Waste Heat Recovery Power Generation Engineering Technical Guidanceimg.tradekey.com/images/uploadedimages/brochures/9/0/... · 2011-05-31 · and power engineering, Mr. Tang began

Technical Guidance

- 1 -

Waste Heat Recovery Power Generation Engineering Technical

Guidance

For Dalian EAST

Prepared By

May 2009

Technical Guidance

- 2 -

Content

1 Company Profile 3

2 CV of Chief Technical Director 10

3

The 1st Generation Technology of Pure Low Temperature

Waste Heat Recovery Power Generation for Cement

Plant

13

4

The 2nd Generation Technology of Pure Low Temperature

Waste Heat Recovery Power Generation for Cement

Plant

18

5

The Typical Technical Specification for the 2nd & 1st

Generation Technology of Pure Low Temperature Waste

Heat Recovery Power Generation for Cement Plant

24

6

Low Temperature Waste Heat Recovery Power

Generation Technology with Additional Fuel Boiler for

Cement Plant

32

7 Patent Technology of Dalian EAST 34

8 Introduction about Power Generation Capacity &

Associated Issues 35

Technical Guidance

- 3 -

1. Company Profile Dalian East New Energy Development Co., Ltd. was founded in December of 2005, as a specialized company that puts the technology into the first priority and integrates all that R&D on technology, engineering design, whole package of equipment, project construction and operation & management in one, engaging in the development of new energy industries such as recovering industrial waste heat energy etc. The company has been certified by ISO2000 quality system authentication in 2007 and been identified as high-tech enterprise in the same year, obtained the design qualification Certificate of Class B on Electric Power Industry (New Energy Power Generation) and related Mechanical Equipment Installation Certificate in 2008. The company currently has a number of practical innovation patents for pure low temperature waste heat recovery power generation for cement kiln, one invention patent technology for long kilns to improve the output and one invention patent technology for changing the waste heat power plant with additional fuel boiler for new type of dry cement kiln into a pure low-temperature waste heat power generation. The company is mainly engaged in: Technology consultation, technology services, technology transfer and project design, whole package of equipment, project management, project services, project contracting for the corresponding application in new energy technology of industrial waste heat energy, solar energy, wind energy, wave (tide) energy, geothermal energy, biogas energy, trash energy, etc. Investment, operation & associated energy contract management for the above mentioned projects. R & D, manufacture, assembly and sales on the technology of the process & equipment for energy saving and other regenerative new energy resources. The company has an excellent management & technical team, which takes the honor of being engaged in energy saving, environmental protection and the earth's resources protection as a job of benefiting the human beings, committed in continuous improvement of the technology of energy saving and comprehensive utilization of resource for China and in achieving the goal of sustainable development to realize their life values and beliefs dedicatedly, step by step. The company currently has a total of 248 employees, wherein, 22 senior engineers and 86 engineers, 5 first level project managers and 10 second level project managers.

Technical Guidance

- 4 -

The technical backbone of the company has participated in and held the introduction, digestion, R & D and promotion for the waste heat recovery power generation for cement kiln in China for many years and made indelible contribution to the development history of the technology of the waste heat recovery power generation for cement kiln in China. The company has the following technologies: (1) The 1st generation thermodynamic system technology of high-temperature

two-stage waste heat recovering power generation for long kiln; design and manufacturing technology for horizontal high temperature waste heat boiler equipment, with the primary steam parameters of 1.6~2.45MPa—360~400℃.

(2) The 2nd generation thermodynamic system technology of high-temperature

two-stage waste heat recovering power generation for long kiln; design and manufacturing technology for horizontal high temperature waste heat boiler equipment, with the primary steam parameters of 3.82MPa—450℃.

(3) The 3rd generation thermodynamic system technology of high-temperature

two-stage waste heat recovering power generation for long kiln; design and manufacturing technology for vertical high temperature waste heat boiler equipment, with the primary steam parameters of 3.82MPa—450℃.

(4) Technology of low temperature waste heat recovery power generation with

additional fuel boiler for cement kiln (for new type of dry Kiln and various types of preheater kiln) & the design and manufacturing technology of additional fuel (coal powder) boiler, the 1st Generation suspension preheater waste heat recovery boiler (SP boiler) and the 1st Generation clinker cooler waste heat recovery boiler (AQC boiler)

Technical Guidance

- 5 -

(5) Technology of low temperature waste heat recovery power generation with additional fuel (poor quality fuel like gangue and trash) boiler for cement kiln (for new type of dry kiln and various types of preheater kiln) & the design and manufacturing technology of fluid-bed boiler, the 2nd Generation suspension preheater waste heat recovery boiler (SP boiler) and the 2nd Generation clinker cooler waste heat recovery boiler (AQC boiler)

(6) Technology of pure low temperature waste heat recovery power generation-for

low parameters mixed pressure steam admission (with secondary steam) type of turbine stable secondary steam thermodynamic system configuration.

(7) 1st Generation Technology of pure low temperature waste heat recovery power

generation for new type of dry kiln.

Technical Guidance

- 6 -

(8) The 3rd Generation of design and manufacturing technology for high

temperature & two-stage waste heat recovery power generation for long kiln & vertical high & low temperature waste heat boiler equipment, and low pressure & large capacity of secondary steam type of turbine with stable secondary steam parameter thermodynamic system configuration. The steam parameters are: 1.27～3.82MPa——340～450℃ for primary steam and 0.15～0.3MPa—saturated～180℃ for secondary steam.

(9) The technology renovation of long kilns to increase the output and the

thermodynamic system technology of medium-temperature & two-stage waste heat recovery power generation by using the technology of calciner and 1-2 stage pre-heater, and the design and manufacturing technology of changing the corresponding high-temperature waste heat boiler into a vertical medium-temperature and vertical low-temperature waste heat boiler.

Technical Guidance

- 7 -

(10) The design and manufacturing technology of clinker cooler waste heat boiler (AQC boiler) and the waste heat recovery boiler integrated with additional fuel boiler in one piece.

(11) The design and manufacturing technology of the 3rd generation preheater

waste heat recovery boiler (natural cycle SP boiler) and the 3rd generation clinker cooler waste heat recovery boiler (natural cycle steam and hot water AQC boiler); and the thermodynamic system technology of low-temperature two-stage supplementary waste heat recovery boiler for cement kiln which is used Biofuels as the fuel.

(12) The technology of low energy consumption for new type of dry cement

production with a medium temperature two-stage waste heat recovery power generation system, and the design and manufacturing technology of corresponding vertical medium-temperature and low-temperature waste recovery heat boiler(HPH Boiler、HPL Boiler), steam turbine with secondary steam, two-stage preheater and calciner equipment.

Technical Guidance

- 8 -

(13) The 2nd generation of pure low-temperature waste heat power generation

technology for new type of dry cement kiln has determined the technical approach improvement for pure low-temperature waste heat power generation for cement kiln，a number of specific technical measures has been invented correspondingly to make the generating capacity technology of pure low-temperature waste heat power generation for cement kiln been improved 12.5% - 31.25% and the operation rate for power plant 2.5% than the 1st generation.

Technical Guidance

- 9 -

- (14) The process technology & equipment design and manufacture technology

of waste heat recovery from cement kiln shell for domestic purpose, such as heating service, refrigeration and air conditioning.

(15) DCS technology for power plant and cement production line. (16) The design and manufacturing technology of auxiliary equipment for

waste heat recovery power generation (valve actuators, special cleaning device for boiler, special deaerator, special pump condenser without power and recycled water pump, ect.)

(17) The technology of waste heat recovery power generation for industries

such as steel & iron making, metallurgical, glass etc.

Technical Guidance

- 10 -

2. CV of Chief Technical Director Chief Technical Director of the company—Mr. Tang Jinquan, Professor Senior Engineer: - After graduated from Harbin Institute of Technology majoring thermal energy

and power engineering, Mr. Tang began his career in TCDRI (Tianjin Cement Industry Design & Research Institute)

- Engaged in design for cement production process from 1983 to June of 1985 - Engaged in cement production process, heating service & ventilation and

waste heat recovery power generation from June of 1985 to October of 1989. As the head of waste heat recovery power generation R&D group and heating service & ventilation group in TCDRI, he took charge of the fulfillment of the technical innovation for 1st generation technology & equipment of high temperature waste heat recovery power generation for long kiln, which had been developed to be the 2nd generation technology & equipment.

- As the head and technical principal of national brainstorm team on National Science & Technology Development Program of 8th Five-year for WHR power generation (including 11 members from 4 organs) organized by the State Building Materials Bureau in 1989, prepared the report for project approval of National Science & Technology Development Program of 8th Five-year for WHR power generation <The Research and Development for the Technology & Equipment of Low Temperature Waste Heat Recovery Power Generation for Cement Kiln>, putting forward that the development for the technology & equipment of low temperature waste heat recovery power generation for cement kiln in China shall follow the technical strategy in two steps to tally with the characteristics of China, i.e. the first step: research and develop <The Technology & Equipment of Low Temperature Waste Heat Recovery Power Generation with Additional Fuel Boiler for Cement Kiln>, and the second step: further research and develop <The Technology & Equipment of Pure Low Temperature Waste Heat Recovery Power Generation for Cement Kiln> basing on success of <The Technology & Equipment of Low Temperature Waste Heat Recovery Power Generation with Additional Fuel Boiler for Cement Kiln>.

- Further educated in Engineering Thermal Physics Department of Tianjin University during January and December of 1991, majoring <The Principle of Steam Turbine and Thermal Power Plant Engineering>.

- Further educated in MAX company in City of Philadelphia, USA during February and May of 1994 on Automation System for Power Plant.

- Appointed to be the director of Waste Heat Recovery Power Generation Department in TCDRI basing on the national brainstorm team on National Science & Technology Development Program of 8th Five-year for WHR power generation organized by the State Building Materials Bureau in 1995

Technical Guidance

- 11 -

- Promoted to be senior engineer and awarded the honor of China’s Youth Academic Pioneer by State Building Materials Bureau in 1995. He has completed the technical negotiation with NEDO (a Japanese company) and plant design for the project using complete set of Japanese equipment (as gift) to set up a 6480kW pure low temperature WHR power plant for Ningguo Cement Company’s new type of dry cement kiln with clinker output of 4000TPD.

- In November of 1996, he completed the brainstorm project of “technology and equipment developing for combined power generation with WHR and additional fuel boiler” and having been awarded the national prize for excellent achievement of key R&D project, and as a great honor, he was interviewed by the highest leaders of Party and State in person, such as Chairman Jiang Zemin etc.

- In 1997, he held and gave lectures for national advanced study class of waste heat recovery power generation for cement kiln in three semesters for the State Building Materials Bureau and gave lectures for French Engineer School.

- GM of Tianjin Nengda Technical Development Co. Ltd (affiliated to TCDRI) in August of 1998, which was the original of SINOMA.

- He held and finalized the 1st Generation Technical Solution of Pure Low Temperature Waste Heat Recovery Power Generation for New Type of Dry Kiln during December of 1999 and May of 2001, to establish the foundation for the development of pure low temperature waste heat recovery power generation technology for cement kiln in China.

- In May of 2001, he resigned his job in TCDRI and set up a cooperative company namely “Hangzhou Qianchao Engineering Technology Co., Ltd.” In title of chairman and general manager.

- During May of 2001 and October of 2005, one by one, he held the completion for: R & D for the technology and equipment of high temperature two-stage waste heat recovery power generation for long kiln, technical innovation and R & D to increase the output and decrease the consumption for long kiln, technical development of new type of dry cement clinker production line for two-stage preheater and precalciner kiln equipped with medium & low temperature waste heat recovery power plant, the design and manufacturing technology of the 3rd generation preheater waste heat recovery boiler (natural cycle SP boiler) and the 3rd generation clinker cooler waste heat recovery boiler (natural cycle steam and hot water AQC boiler); and the thermodynamic system technology of low-temperature two-stage supplementary waste heat recovery boiler for cement kiln which is used Biofuels as the fuel, and the completion of the design and commissioning of low temperature waste heat recovery power plants with additional fuel boiler for 9 lines of cement kilns, which accelerates the experience for improving waste heat recovery power generation technology of new type of dry kiln to establish the technical

Technical Guidance

- 12 -

foundation for the development of the technology & equipment of the 2nd generation of pure low temperature waste heat recovery power generation for new type of dry kiln.

- During May of 2005 and July of 2007, he led the completion of R&D for the 2nd technology and equipment of pure low temperature waste heat recovery power generation for cement kiln, and developed a number of detailed technical measures (6 practical new type patents and 3 patent technologies).

- In October of 2005, set up Dalian East Energy Engineering Co., Ltd. (which becomes Dalian East New Energy Development Co., Ltd.) as one of the founders, in title of Chief Engineer.

- He has been leading the R&D of 3rd generation technology of pure low temperature waste heat recovery power generation for cement kiln since 2007.

- He has been leading the completion of 14 kinds of waste heat recovery power generation system technology, R&D for 32 kinds of waste heat recovery power generation equipments, 53 waste heat recovery power projects for cement plant, the design and technical revamping for 9 new production lines, and the start-up & commissioning of waste heat recovery power plants for 25 cement plants.

- He has published 29 pieces of technical paper in the field of waste heat recovery on the academic publication at the level of provincial, ministerial and higher, and been awarded the prize of first class for excellent paper at state level.

Technical Guidance

- 13 -

3. The 1st Generation Technology of pure

low-temperature WHR power generation for

Cement kilns 3.1 Definition and Feature

(1) Definition: it is the technology that transfers the waste heat of the flue gas coming from both the pre-heater and the clinker cooler at rear and front of the kiln respectively, which is of new type of dry cement kiln (hereinafter referred as cement kiln in short), into power energy by using steam of 0.69MPa～ 1.27MPa—280℃～ 330℃ without impairing the production output & quality of cement clinker, lowering the cement kiln operation rate, changing cement production technology process & machines, nor increasing the consumption of power energy and heat on clinker as the premise.

(2) Features: The 1st Generation Technology for pure low-temperature WHR power generation for cement kilns also features as two points or more as follows besides the above mentioned definition: The cooler has only one flue gas exhaustion outlet for power generation; The temperature of the primary steam admission to the turbine is not adjustable but varies along with the temperature fluctuation of the flue gas from the cement kiln; The feed water systems for respective AQC boiler and SP boiler are of serial systems; Deaeration system by boiler feed water uses extra consumption of chemicals or power energy.

3.2 Key Points of the Technology and Construction of Thermodynamic

System

(1) Key Points of the Technology Set up a waste heat recovery boiler for the suspending preheater at rear of the cement kiln (hereinafter referred as SP boiler in short) served by recovery of the hot air exhausted from the suspending preheater, and extract the total flue gas exhausted from the clinker cooler at front of the cement kiln as two segments from the clinker cooler (see Diagram 1), wherein, an extraction outlet is opened at the middle part of the clinker cooler to serve extracting flue gas below 400℃ for clinker cooler waste heat recovery boiler (hereinafter referred as AQC boiler in short),

Technical Guidance

- 14 -

meanwhile, another extraction outlet is set up to serve extracting flue gas below 120℃ which is exhausted to the atmosphere directly. Equip a steam turbine and power generation system for the steam generated by WHR boiler; the parameters of the primary steam by power generation plant is 0.69～1.27MPa—280～330 and the actual power generation capacity ℃

basing on per tonnage of clinker is 3140kJ/kg clinker ——28～35kwh (2) Construction of Thermodynamic System

a) The thermodynamic power system mode for the 1st Generation Technology of WHR power generation for cement kiln consists of the following three kinds: Mono pressure pure low temperature WHR power generation technology without secondary steam. (See diagram 1.) b) Combined flash evaporation pure low temperature WHR power generation technology with secondary steam. (See diagram 2.) c) Multi-pressure pure low temperature WHR power generation technology with secondary steam. (See diagram 3.)

Diagram 1 Basic construction for mono-pressure without secondary steam pure

low temperature WHR power generation thermodynamic system

Technical Guidance

- 15 -

Diagram 2 Basic Construction for combined flasher with secondary pure low

temperature WHR power generation thermodynamic system

Diagram 3 Basic construction for dual-pressure with secondary pure low

temperature WHR power generation thermodynamic system

Technical Guidance

- 16 -

3.3 Features of the Technology Abovementioned three modes have no substantial difference but share the common features as: Extract the total flue gas exhausted by the clinker cooler from the cooler as two segments, where a flue gas exhaustion outlet is opened in the middle part of the cooler to extract flue gas below 400 ℃ to produce steam & hot water through AQC boiler which is used for WHR power generation conversion through a set of steam turbine & generator, and another flue gas exhaustion outlet is set up at the rear of the cooler to extract flue gas below 120 , which is emitted into the ℃ atmosphere directly. The waste heat of the flue gas exhausted from the preheater is used for producing steam through SP boiler. The steam generated by SP boiler and the steam & hot water generated by AQC boiler respectively mix before converting into power energy through a set of steam turbine & generator. The temperature of the flue gas exhausted from SP boiler is not adjustable meanwhile meet the maximum drying temperature for raw meal & fuel demanded by the cement production, i.e. the flue gas from the preheater is used for drying the raw & fuel material to meet cement production primarily and the residual waste heat of the flue gas is used for power generation. As the most important characteristic, the parameters of the primary steam for power generation totally vary at range of 0.69～1.27MPa-280～330 .℃ The differences among the three modes are shown as: (1) while the AQC is producing the low pressure & low temperature steam at

0.69～1.27MPa-280～330 , it is reproducing either saturate low pressure & ℃

low temperature steam at 0.1～0.5MPa-saturated～160 or hot water at ℃

105～180 ;℃ (2) Steam turbine is used as the type of either with or without secondary steam; (3) Due to the same flue gas parameter, the power generation capacity will be

100% if based on the first mode, about 101.5%~102% if based on the second mode and about 102~103% if based on the third mode;

(4) The first mode is not affected by the relative location between the steam turbine house and the cooler. The second mode (i.e. combined flash evaporation with secondary steam) is proper for the case that the steam turbine house locates far away from the cooler. The third mode is proper for the case that the (dual-pressure with secondary steam) steam turbine house locates closely to the cooler.

3.4 Power Generation Capacity by Theoretical Calculation

Technical Guidance

- 17 -

The 1st Generation Technology of WHR power generation fills the gap in China's cement industry, and laid the foundation and accumulated valuable experience for China to develop this technology. However, due to the limitations of technical condition, comparing to new type of dry kiln, the level of the 1st Generation Technology of WHR power generation is equivalent to the level of new type of dry kiln at the beginning of last 90s with certain problems existing among any following aspects such as investment, power generation capacity, operational stability, the lifetime of BTG, or operational adjustability. Whereas the 1st Generation Technology of WHR power generation is no good use of clinker cooler exhaustion temperature, system has only been in the production of low-temperature & low pressure steam, therefore, the waste heat has not been recovered in cascade as per the temperature distribution so as to make the thermodynamic power generation efficiency of the circulation system much too low and the waste heat is not able to reach its rated power generation capacity. Regarding the WHR power generation capacity for cement kiln with a 5-stage preheater, under the conditions such as, the flue gas temperature is not higher than 330 at SP, ℃ and the required flue gas temperature is more than 170 to ℃

meet drying the raw material and to meet the required flue gas parameter for coal mill drying, without impacting the cement clinker output and operational rate, increasing the consumption of heat and power on finished production of cement clinker, changing the drying heat supply for raw material to produce cement, nor changing the cement production process or plant, theoretically, the WHR power generation capacity basing on per tonnage of clinker output has no way to be over 3140kj/kg-28~35kwh (for the cement kiln with actual clinker output of 2750t/d, heat consumption less than 3140kj/kg or the flue gas temperature at the outlet of the preheater lower than 330℃, and the drying temperature for raw material higher than 170 , the ℃ maximum power generation output by theoretical calculation is 4000KW or 8000KW for the cement kiln with clinker output of 5500t/d).

Technical Guidance

- 18 -

4. The 2nd Generation Technology of pure

low-temperature WHR power generation for

cement kilns 4.1 Definition and Feature (1) Definition: it is the technology that transfers the waste heat of the flue gas

coming from both the pre-heater and the clinker cooler at rear and front of the kiln respectively, which is of new type of dry cement kiln (hereinafter referred as cement kiln in short), into power energy by using steam of 1.27MPa～3.43MPa—340℃～435℃ without impairing the production output & quality of cement clinker, lowering the cement kiln operation rate, changing cement production technology process & machines, nor increasing the consumption of power energy and heat on clinker as the premise.

(2) Features: The 2nd Generation Technology for pure low-temperature WHR power generation also features as two points or more as follow besides the above mentioned definition: The cooler has two flue gas extraction outlets or more for power generation (patent of Dalian East New Energy Development Co., Ltd.); An independent superheater is set up near AQC, through which the temperature of the primary steam admission to the turbine is adjustable but does not follow the temperature fluctuation of the flue gas from the kiln (patent of Dalian East New Energy Development Co., Ltd.); An independent superheater is set up inside C1 (the last stage of preheater) to improve the operational rate & stability of the power plant (patent of Dalian East New Energy Development Co., Ltd.); The water feed systems for respective AQC boiler and SP boiler are of parallel systems which do not affect mutually but with respective independence (patent of Dalian East New Energy Development Co., Ltd.); Deaeration system by boiler feed water uses low-temperature waste heat below 145 without the consumption of extra chemicals or power energy℃ (patent of Dalian East New Energy Development Co., Ltd.); An adjusting unit is equipped at the outlet of the SP boiler to adjust the outlet flue gas temperature to meet the various drying temperature requirement for

Technical Guidance

- 19 -

various humidity in different seasons (patent of Dalian East New Energy Development Co., Ltd.); The cooling air from the clinker cooler is of circulation (patent of Dalian East New Energy Development Co., Ltd.).

4.2 Key Points of the Technology and Construction of Thermodynamic System

(1) Key Points of the Technology

Set up a suspension preheater boiler to recover the hot air emitted from the suspension preheater at rear of the kiln and the flue gas emitted from the clinker cooler through changing the emission method as three segments from the clinker cooler, wherein, a flue gas extraction outlet is opened in the front-middle part of the cooler to extract a small quantity of flue gas below 500 separately℃ to serve an independent clinker cooler flue gas waste heat superheater (hereinafter as ASH superheater); a flue gas extraction outlet is opened in the middle part of the cooler to recover the flue gas below 360℃ emitted from the clinker cooler to serve a hot air quick cooler boiler (hereinafter as AQC boiler); and another flue gas exhaustion outlet is set up at the rear of the cooler to extract flue gas below 120 , which is emitted into the ℃

atmosphere directly. equip a steam turbine with secondary steam for the waste heat boiler and the waste heat superheater; the parameters of the primary steam for power generation system is 1.27～3.43MPa—340～435 , ℃ the parameters of the secondary steam are 0~0.2 MPa—saturated~160 and the ℃

power generation capacity is 3140kJ/kg clinker output ——38～45kwh/t clinker output.

(2) Construction of Thermodynamic System The prevailing thermodynamic power system mode for the 2nd Generation Technology of WHR power generation for cement kiln consists of the following two kinds: The first mode is of basic configuration system, for whose construction, see Diagram 4. The second mode is of adjustable configuration system, for whose construction, see Diagram 5.

Technical Guidance

- 20 -

Diagram 4 Basic configuration mode for 2nd generation technology of WHR

power generation thermodynamic system

Diagram 5 Adjustable configuration mode for 2nd generation technology of WHR

power generation thermodynamic system

Technical Guidance

- 21 -

4.3 Features of the Technology Regarding both the waste heat recovery method for the flue gas from the clinker cooler and the construction of the thermodynamic system by the 2nd Generation Technology of pure low temperature WHR power generation for cement kiln, the new generation technology not only inherits the technology features of the predecessor but also specifies itself by other characteristics as follow, The cooler works in a multi-stage way of extracting the flue gas to create the conditions for providing relative high temperature & high pressure primary steam parameters for the power plant and realizing the recovery of waste heat in cascade as per the flue gas temperature; Install a separate clinker cooler flue gas superheater to create conditions for adjusting and controlling the steam parameters (such as temperature, pressure); The power plant uses the relative high temperature and high pressure primary steam parameters as 1.27~3.43MPa—340~435 to ensure the improvement of ℃

the WHR power generation capacity; The turbine uses the way of multi-stage mixed steam feed (i.e. with secondary steam mode), and AQC boiler uses the relative high pressure steam segment as 1.47~3.43MPa, low pressure steam segment as 0.15~0.5MPa and 100~120 ℃

hot water segment arrangement of heating surface to provide the measures for changing the low pressure and low temperature steam & hot water of 0.15~0.5MPa generated by flue gas waste heat below 190 into power energy℃ and using 100~120℃ hot water to serve feed water & deaeration by flue gas waste heat below 145℃; The water feed systems for respective AQC boiler and SP boiler are of independent system which creates the conditions for the operation of both boilers without mutual influence; Deaeration system by boiler feed water uses low-temperature waste heat below 145 without the consumption of extra chemicals or power en℃ ergy. An adjusting unit is equipped at the outlet of the SP boiler to adjust the outlet flue gas temperature to follow the various drying temperature requirement for cement production so as to provide the measures of converting the waste heat into the power energy to the utmost. 4.4 The Achievement by the 2nd Generation Technology of Pure Low

Temperature Waste Heat Recovery Power Generation for Cement Kiln

Technical Guidance

- 22 -

For the 2nd Generation Technology of pure low temperature power for cement kiln, comparing with the existing problems by the 1st Generation Technology of WHR power generation, in case of without impacting the heat consumption of cement clinker, meeting the required minimum temperature of 170 for drying raw ℃ meal & fuel, without changing cement production process and equipments, nor impacting the cement kiln operation, the achievement by the 2nd generation technology of pure low temperature waste heat recovery power generation for cement kiln is as follow: (1) The waste heat is able to generate either sub-medium pressure or medium

pressure steam of saturated-overheat 450 , low pressure and low ℃

temperature steam of 01.~ 05MPa saturated-180 , and ℃ hot water of 85~110 at the same time;℃

(2) The thermodynamic circulation system is able to use sub-medium pressure and medium temperature parameters, to improve the thermodynamic circulation system efficiency, and to realize the principle of heat utilization in cascade as per the fluctuation of temperature meanwhile making full use of the waste heat as per various flue gas temperature from the cement kiln;

(3) The 2nd Generation Technology of pure low temperature power generation for cement kiln thermodynamic circulation system, circulation parameters and flue gas extraction method coverts the flue gas waste heat from cement kiln by its quality into the power energy to the maximum extent so that the WHR power generation capacity is improved highly than the 1st Generation Technology pure low temperature power generation for cement kiln to reach 3140KJ/Kg---38~45kWh/t in actual. Comparing with the 1st Generation Technology of pure low temperature WHR power generation, the WHR power generation capacity per ton of clinker is improved 12.%~31.25% at the premise of the constant heat consumption of clinker;

(4) It solves the problem that the primary steam temperature of the 1st Generation Technology of pure low temperature power generation is not adjustable so as to impact the lifetime of the steam turbine;

(5) Employing primary steam with quite high pressure and temperature creates the conditions for the steam turbine operation with smooth parameters of primary steam pressure and temperature in a large various range (When the primary steam pressure and temperature are designed as 2.29MPa-370 , ℃

the actual operational various range is able to reach 1.27~2.47MPa, 325 ~400 ); yet the ℃ ℃ actual permissible various range of the turbine primary steam pressure and temperature for the 1st Generation Technology of the pure low temperature power generation is much smaller (When the primary steam pressure and temperature are designed as 0.689MPa-317 , the ℃

actual operational various range is able to reach 0.49~0.98MPa, 292 ~330℃ ℃ only). Therefore, meanwhile being able to improve the WHR power generation capacity, the 2nd Generation Technology of pure low temperature power

Technical Guidance

- 23 -

generation is much better than the 1st Generation Technology on the aspects of operational rate & reliability of the power generation system, and adaptability for the fluctuation of the cement kiln production due to the permissible operational various range of the primary steam parameters by the 2nd Generation Technology of WHR power generation much larger than that by the 1st Generation;

(6) It solves the problems such as the mutual influence because of the serial connection between AQC boiler and SP boiler, difficult controlling water feed system, and unstable service of the system etc.;

(7) Due to the adjustable unit set up at SP boiler to govern the temperature of the outlet flue gas from the SP boiler, without control the existing gas duct damper on the cement line, the temperature of the outlet flue gas from the SP boiler can be along with the various temperature required by drying raw meal & fuel for cement production as well as convert the waste heat into the power energy to the utmost.

(8) Serving the feed water & deaeration system in a thermal way of low temperature waste heat of below 145℃，it has no longer the consumption of extra chemical dose or power energy as wells improve the stability for feed water and the continuity of the boiler operation with the requirement on the oxygen content in the feed water.

Above mentioned points have been already proven by the WHR power plants put into production.

Technical Guidance

- 24 -

5. Technical Specifications for the 2nd & 1st

Generation Technology of Pure Low Temperature

Waste Heat Recovery Power Generation for

Cement Kiln with Typical Clinker Output

5.1 Typical Technical Specifications for the 2nd Generation Technology of Pure Low Temperature Waste Heat Recovery Power Generation for Cement Kiln

Technical Specifications of Pure Low Temperature Waste Heat Recovery Power Generation for New Type of Dry Cement Kiln with Typical Clinker Output of 1300tpd (by the 2nd Generation Technology)

Description Value Parameters of hot air from PH 75000～105000Nm³/h—320～350℃ Parameters of flue gas from clinker cooler 56000～85000Nm³/h—260～290℃

Actual clinker output 1000～1500tpd Designed power capacity 2.0～3.0MW Operational rate of the power plant

As 97.5% of the operational rate of cement kiln

Power self-consumption by the power plant 6.5～7.2%

Posts and staff 17(persons) AQC boiler, superheater 1set

SP boiler, superheater 1set

Steam turbine 1set

Main equipment

Generator 1set

Technical Guidance

- 25 -

Technical Specifications of Pure Low Temperature Waste Heat Recovery Power Generation for New Type of Dry Cement Kiln with Typical Clinker

Output of 2000tpd (by the 2nd Generation Technology) Description Value

Parameters of hot air from PH 108000～163000Nm³/h—320～340℃ Parameters of flue gas from clinker cooler 88000～133000Nm³/h—270～290℃






Steam turbine 1set

Main equipment

Generator 1set









Steam turbine 1set

Main equipment

Generator 1set

Technical Guidance

- 26 -









Steam turbine 1set

Main equipment

Generator 1set









Steam turbine 1set

Main equipment

Generator 1set

Technical Guidance

- 27 -




Actual clinker output 5000～5800tpd Designed power capacity 9.0～12MW Operational rate of the power plant





Steam turbine 1set

Main equipment

Generator 1set

Technical Guidance

- 28 -

5.2 Technical Specifications for the 1st Generation Technology of Pure Low Temperature Waste Heat Recovery Power Generation for Cement Kiln with Typical Clinker Output

Technical Specifications of Pure Low Temperature Waste Heat Recovery Power Generation for New Type of Dry Cement Kiln with Typical Clinker Output of 1300tpd (by the 1st Generation Technology) Description Value Parameters of hot air from PH 75000～105000Nm³/h—320～350℃ Parameters of flue gas from clinker cooler 56000～85000Nm³/h—260～290℃






Steam turbine 1set

Main equipment

Generator 1set

Technical Guidance

- 29 -







Steam turbine 1set

Main equipment

Generator 1set







Steam turbine 1set

Main equipment

Generator 1set

Technical Guidance

- 30 -







Steam turbine 1set

Main equipment

Generator 1set







Steam turbine 1set

Main equipment

Generator 1set

Technical Guidance

- 31 -







Steam turbine 1set

Main equipment

Generator 1set


Actual clinker output 5000～5800tpd Designed power capacity 7.5～10MW Operational rate of the power plant





Steam turbine 1set

Main equipment

Generator 1set

Technical Guidance

- 32 -

6. The Technology of Low Temperature Waste Heat

Recovery Power Generation with Additional Fuel

Boiler for Cement Kiln 6.1 Features of the Technology An HRSG-SP recovering the waste heat from the 300∼350°C flue gas exhausted from SP; An HRSG-AQC recovering the waste heat from the 300∼400°C hot air attracted from AQC; An additional fuel boiler served by gangue, trash or biogas adjusts the the parameters of the steam and hot water coming from AQC & SP boiler until meeting the admission for the turbine. 6.2 The Construction of the Thermodynamic System

Diagram 6 the Mode of the Construction of Low Temperature Waste Heat Recovery Power Generation Thermodynamic System with Additional Fuel Boiler

for Cement Kiln

Technical Guidance

- 33 -

6.3 Installed Power Generation Capacity for Power Plant Basing on the resource and supply capacity of gangue, trash or biogas, the installed power generation capacity for low temperature waste heat recovery power plant with additional fuel boiler for cement kiln can be determined as less than 80% of total consuming power for the whole cement plant. In this case, energizing from the cement plant to grid inversely will be avoided. In case of the confirmed waste heat from the cement kiln, the capacity of the additional fuel boiler is determined by the installed power generation capacity.

Technical Guidance

- 34 -

7. Patent Technology of Dalian East New Energy

Development Co., Ltd. 7.1 Practical New Pattern 1- Preheater C2 Waste Heat Recovery Power

Generation System (Technology for steam superheater built-in preheater C2). 7.2 Practical New Pattern 2- Clinker Cooler Waste Heat Recovery Power

Generation System (Technology for multi-stage waste heat extraction from the clinker cooler).

7.3 Practical New Pattern 3- Clinker Cooler Circulation Air (Technology for

circulation air used by clinker cooler). 7.4 Practical New Pattern 4- Multi-stage Waste Heat Extraction from the Clinker

Cooler System (2) (Technology for improving multi-stage waste heat extraction from the clinker cooler).

7.5 Practical New Pattern 5- An Independent Steam Superheater System for

Clinker Cooler. 7.6 Practical New Pattern 6- Adjusting Unit for the Temperature of Outlet Hot Air

from SP boiler (Technology for low pressure steam segment built in SP boiler).

Technical Guidance

- 35 -

8. Introduction about Power Generation Capacity

& Associated Issues

8.1 About Designed Average Power Generation Capacity (attributed to the

issue that cement plant owners seldom study in depth)

8.1.1 Several Aspects Working on the Designed Average Power Generation

Capacity of WHR for a Cement Plant:

At the premise of all the definite parameters of the waste heat from cement kiln, such as flowrate & temperature of the hot air from the preheater outlet, flowrate & temperature of the flue gas for drying raw meal and the flowrate & temperature of the hot air from the clinker cooler, the designed average power generation capacity is also worked on by other aspects probably as follows besides the technical proposal for WHRPP for a cement plant as the main consideration, to calculate the designed average power generation capacity,:

8.1.1.1 The lower the exhaust steam pressure from the turbine, the larger the designed average power generation capacity.

8.1.1.2 The higher the turbine internal high & low pressure steam admission efficiency factors (F1, F2 respectively), the efficiency factor of turbine mechanical, heat dissemination and self-consumption power loss (F3), and generator efficiency factor (F4), the larger the designed average power generation capacity.

8.1.1.3 The larger the efficiency factor of air duct heat dissemination, bypass air duct leakage, or steam & water pipe steam leakage & heat dissemination (F5), the larger the designed average power generation capacity.

8.1.2 Dalian East New Energy Development Co., Ltd. puts the abovementioned three aspects into the consideration on the calculation of designed average power generation capacity for cement kiln as follows to calculate the designed average power generation capacity for a WHRPP:

8.1.2.1 The turbine steam exhaust pressure is considered as 0.007MPa, the temperature of the exhausted steam is considered as 39℃ and the required temperature of the cooling water is 26℃.

8.1.2.2 F1 is considered as 82%, F2 is considered as 80%, F3 is considered as 97.5%, F4 is considered as 97.5%, generally.

8.1.2.3 F5 is generally at the range of 91~93% for a kiln of 2,500TPD-level

Technical Guidance

- 36 -

output, and 93~95% for a kiln of 5,000TPD-level output respectively. 8.1.3 Other suppliers put the abovementioned three aspects into the

consideration on the calculation of designed average power generation capacity for cement kiln as follows to calculate the designed average power generation capacity for a WHRPP:

8.1.3.1 The turbine steam exhaust pressure is considered as 0.0053MPa, the temperature of the exhausted steam is considered as 33.9℃ and the required temperature of the cooling water is 21℃.

The problems will exist when the turbine steam exhaust pressure is considered as 0.0053MPa: When the required the temperature of the cooling water is not higher than 21 , the ambient daily average℃ dry ball temperature has to be not higher than 20 subsequently. Unfortunately, ℃

the period with daily average temperature lower than 20 is very short, ℃

and what is more, the pressure of exhausted steam from the turbine in the actual operation is hardly able to meet 0.0053MPa, therefore, the actual power generation capacity can in no way guarantee to meet the designed power generation capacity proposed by these suppliers.

8.1.3.2 F1 is considered as 85% or even higher, F2 is considered as 83% even higher, F3 is considered as 98.5% even higher, F4 is considered as 98.5% even higher, generally.

The problems will exist when above four efficiency values (F1&2&3&4) are considered as F1=85% or even higher, F2=83% or even higher, F3=98.5% or even higher, F4=98.5% or even higher, which are provided by the manufacturers are to be met only under ideal operation condition and rated state, however, during the actual operation of the WHR power plant, either steam parameters, power capacity or cooling water operation condition vary too much to keep the installation in operation under ideal operation condition or rated state for a long term, so that the actual efficiency values will be lower than those provided by the manufacturers, i.e. their actual power generation capacity is not able to meet the calculated power generation capacity of design by these suppliers.

8.1.3.3 F5 is generally considered as 100%.

The problems will exist when F5 is generally considered as 100%: In practice, since the valve of the flue gas duct is not possibly closed completely, it is impossible for flue gas duct or steam pipe to have zero heat dissemination or zero air (steam) leakage, F5 is never 100%, which means their actual power generation capacity will be far away to meet the designed & calculated power generation capacity by these suppliers.

Technical Guidance

- 37 -

8.2 The designed average power generation capacities for new type of dry kiln with clinker output of 5800TPD proposed by suppliers

Take a WHR power plant for a cement kiln with output of 5800TPD for example, its conditions of the waste heat are as follows: actual clinker output of 5800TPD, hot air from the preheater with the parameters of 380,000Nm3/h--330 , the required maximum drying temperature of 2℃ 20 , ℃

and hot air from the clinker cooler with the parameters of 295,000 Nm3/h--300 )℃ .

8.2.1 The designed average power generation capacities for this project proposed by Dalian East New Energy Development Co., Ltd.

8.2.1.1 The technical proposal for this project by Dalian East New Energy Development Co., Ltd.

According to the conditions of the flue gas waste heat from the cement kiln, three options are shown for this project as follows:

Option 1: it is of dual-pressure technical solution with the parameters of the primary steam & secondary steam admission into the steam turbine as high pressure of 2.29MPa － 370 and as low pressure of ℃

0.2MPa-150 overheated respectively (hereinafter referred as the 2nd ℃

Generation Technical Solution in short).

Option 2: it is of mono-pressure technical solution with the parameters of the primary steam (without secondary steam) admission into the steam turbine as high pressure of 1.27MPa － 315 (hereinafter ℃

referred as the 1st Generation Technical Solution 1 in short).

Option 3: it is of dual-pressure flashing evaporation technical solution with the parameters of the primary steam & secondary steam admission into the steam turbine as high pressure of 0.689MPa－315 and as ℃

low pressure of 0.14MPa- saturated respectively (hereinafter referred as the 1st Generation Technical Solution 2 in short).

8.2.1.2 The designed average power generation capacities of the three options

As per the flue gas condition for this project and the available guarantee in the actual operation, the pressure of exhausted steam from turbine is considered as 0.007MPa, F1 is considered as 82%, F2 is considered as 80%, F3 is considered as 97.5%, F4 is considered as 97.5% and F5=93.5%. We provide the detailed calculation and the calculation procedure, which is for the owner to check, for the designed average

Technical Guidance

- 38 -

power generation capacities of three options in our technical proposal, i.e. 2nd Generation Technical Solution, 1st Generation Technical Solution 1 and 1st Generation Technical Solution 2. Wherein,

By 2nd Generation Technical Solution, the designed power generation capacity is 9,330 kW;

By 1st Generation Technical Solution 1, the designed power generation capacity is 7,840 kW;


These are the maximum power generation capacities which we guarantee in our technical proposal, to be realized at the following premises: the actual clinker output of 5,800 TPD, hot air from the preheater with the parameters of 380,000Nm3/h--330℃, required maximum drying temperature of 220 , and hot air from the clinker ℃

cooler with the parameters of 295,000 Nm3/h--300℃

8.2.2 The designed average power generation capacity proposed by other suppliers

Supposing, the exhaust steam pressure of turbine is considered as 0.0053MPa; F1 =85%; F2 =83%; F3 =98.5%; F4 =98.5%; F5 =100%;

We also provide the detailed calculation and the calculation procedure, which is for the owner to check, for the power generation capacities of three options in our technical proposal, i.e. 2nd Generation Technical Solution, 1st Generation Technical Solution 1 and 1st Generation Technical Solution 2. Wherein,

By 2nd Generation Technical Solution, the designed power generation capacity is 10,850 kW;



These designed & calculated power generation capacities basing on the flue gas conditions in this project have no way to be realized by either 2nd Generation Technical Solution or 1st Generation Technical

Technical Guidance

- 39 -

Solutions (We do not propose these figures of power generation capacities because we think these values of efficiency factors are considered too high to realize in actual)

8.3 About the Weight of Waste Heat Recovery Boiler (HRSGs) and other Aspects that work on the Actual Average Power Generation Capacity (attributed to the issue that cement plant owners seldom pay attention to)

At the premise of the finalization of the technical proposal for a WHRPP, the insufficient heating transferring surface of the boilers (i.e. the heat-exchanging pipes inside the boilers), which fails to meet the actual required, is one of the main reasons that impact the actual average power generation capacity negatively.

Adapting to the fluctuation of cement kiln production line at the same time of transferring the waste heat of flue gas from cement kiln into steam & hot water, a waste heat recovery boiler has to suffice enough heat-exchanging surface which means enough heat-transferring pipes or weight of the waste heat recovery boiler, and in total of which compression heat-transferring parts such as heat-transferring pipes built in the waste heat recovery boiler shall be larger than 53% and other parts such as beams, columns, stairs or platforms etc. shall be not larger than 47%. The actual power capacity of a WHRPP has no way to meet the calculated power capacity by design in case the weight of the waste heat recovery boiler is configured insufficiently.

For the WHRPPs built on a cement kiln production line at level of 5,500~5,800TPD clinker output (with the preheater outlet flue gas temperature of 320~340 ):℃

The total weight of the boiler by the 1st Generation Technical Solution (0.689～1.27MPa－280～330 ) needs about 950~1,000 tons to make the ℃

designed average power capacity of 7,580~8,000 kW available (for the WHRPPs put into operation already in China, the weight of the boilers is only around 850 tons and the actual power generation capacities only range 5,800 kW~7,120 kW); The total weight of the boiler by the 2nd Generation Technical Solution (2.29MPa－370 ) needs about 1,320 tons to make the ℃

designed average power capacity of 8,800~9,600 kW available (which tally with the reality for the WHRPPs put into operation already in China);

Regarding abovementioned project:

To meet designed power generation capacity of 9,330 kW by 2nd Generation

Technical Guidance

- 40 -

Technical Solution with the parameters of 2.29MPa－370 for admission ℃

high pressure steam into the steam turbine, the weight of total boiler needs to be 1,382 tons;

To meet designed power generation capacity of 7,840 kW by 1st Generation Technical Solution 1, as the parameters of 1.27MPa－315 for admission ℃

high pressure steam into the steam turbine, the weight of total boiler needs to be 999 tons;

To meet designed power generation capacity of 7,470 kW by 1st Generation Technical Solution 2, as the parameters of 0.689MPa－315 for admission ℃

high pressure steam into the steam turbine, the weight of total boiler needs to be 957 tons;

For details about the comparison of the actual power generation capacity and boiler weight for the typical WHRPPs put into operation at the level of 5,500~5,800TPD clinker output for cement plants by 2nd Generation Technology or 1st Generation Technology in China, see Chapter 11 The Collection of Actual Operation Information for the Pure Low Temperature Waste Heat Recovery Power Plant for New Dry Method Kiln Cement Plants Put into Production.

The conclusion from abovementioned information collection:

The actual power generation capacity in operation is in compliance with the value of theoretical calculation for the WHR power plant built by using 2nd Generation Technical Solution from Annexure 3 & 4. The substantial reasons of actual power generation capacity in operation is lower than the value of calculation for the WHR power plant built by using 1st Generation Technical Solution lie in: Firstly, during the calculation for designed average power generation capacity design, other suppliers have much higher efficiency factors (F1 & 2 & 3 & 4 & 5) as abovementioned; Secondly, lacking of experience of design or construction, or reducing the investment on purpose during the engineering design for the power plant; Thirdly, the contractor takes some improper technical measures, for example, improper selection of the insulation material for air duct or steam & water pipe, construction quality or insulation thickness leads to great loss of heat dissemination; the over less configuration of the heat-exchanging surface or improper structure style of the boiler leads to its lack of actual production

Technical Guidance

- 41 -

capacity and increase the flowrate of air leakage; improper installation of flue gas ducts & their valves lead to the increase of flowrate of air or gas leakage; Fourthly, the flow speed of steam & water inside the steam & water pipe is designed too large so as to lead too much loss of steam & water pressure etc.

8.4 About the Weight of the Boilers (Heat-transferring surface of the boilers) that works on the investment & operation for a WHRPP (attributed to the issue that cement plant owners seldom pay attention to either)

The 2nd Generation Technical Solution adopts relatively high primary steam pressure with higher saturated temperature (which is 223.9 as the primary ℃

steam pressure of 2.29MPa) so that the heat exchange temperature difference for the boiler is relatively smaller, which is approximately ｛(320-223.9)+15｝/2=55.55 for HRSG℃ -SP boiler of the WHR power plant for abovementioned kiln of 5,500~5,800 TPD that has been put into operation. While the 1st Generation Technical Solutions adopt relatively low primary steam pressure with lower saturated temperature (which is 178.1 ℃

as the primary steam pressure of 0.689MPa) so that the heat exchange temperature difference for the boiler is relatively larger, which is approximately ｛ (320-178.1)+15 ｝ /2=78.45 for the℃ abovementioned HRSG-SP boiler as an example. If 55.55 is considered as the base of the ℃

exchanging temperature difference for the boiler under 2nd Generation Technical Solution, the exchanging temperature difference for the boiler under the 1st Generation Technical Solutions is 141.2% of that under 2nd Generation Technical Solution.

Because of the different heat exchanging temperature difference for the boiler, for the specific cement kiln: the heat exchanging surface for the HRSGs under the 2nd Generation Technical Solution is much larger than that under the 1st Generation Technical Solutions so that the metal weigh of the boiler is much larger, in detail, If the heat exchanging surface for the HRSGs under the 1st Generation Technical Solutions is considered as the base, the heat exchanging surface for the boiler under the 2nd Generation Technical Solution is around 141.2% of that under 1st Generation Technical Solutions; likewise, the metal weight for the boiler under the 2nd Generation Technical Solution is over 125% of that under 1st Generation Technical Solutions. Take the abovementioned WHR power plant which has been put into operation ( at level of 5,500~5,800 TPD) as example: by using the 2nd Generation Technical Solution, the actual metal weight of total HRSGs is about 1,320~1,380 tons, its actual power generation capacity can make around 8,800~9,600 kW available as the designed average power capacity, if this project adopts 1st Generation Technical Solutions, the actual weight of the total HRSGs will be around 950~1,000 tons, to make the designed

Technical Guidance

- 42 -

average power generation capacity of 7,580～8,000KW available, which means the actual weight of total HRSGs by 2nd Generation Technical Solution is around 135% of that by 1st Generation Technical Solutions(for the WHRPP at level of 5,500~5,800 TPD which has been put into operation by 1st Generation Technical Solutions, its actual power generation capacity is only 5,800~7,120KW, because its actual weight of total HRSGs is only 850 tons which is far lower than the practically required tonnage (950~1,000 tons).

Since the heat-transferring surface of the boilers by 2nd Generation Technical Solution is larger than that by 1st Generation Technical Solutions, the investment on the boilers by 2nd Generation Technical Solution is higher than that by 1st Generation Technical Solutions and likewise the investment on a WHRPP by 2nd Generation Technical Solution is larger than that by 1st Generation Technical Solutions if the weigh of the boilers is considered alone. Actually, by 2nd Generation Technical Solution, the parameters of the admission steam is improved so that the actual power generation capacity by 2nd Generation Technical Solution is larger than that by 1st Generation Technical Solutions through increasing the heat-transferring surface of the boilers. Therefore, as a result, the 2nd Generation Technical Solution put the saving of the investment from power plant joint pipes, valves, heat insulation material, hanger support, circulation pump, cooling tower, deaeration system and so on through improve the steam parameters on increasing the heat exchanging surface (the metal weight of HRSGs) so that the unit investment of per kW installed power capacity by 2nd Generation Technical Solution is smaller than that by 1st Generation Technical Solutions by putting investment for a WHRPP on the boilers as the most important equipment; on the other hand, because the heat exchanging surface of HRSGs of 2nd Generation Technical Solution becomes larger, which guarantees substantially that WHRPP can be adapted to the large-scope fluctuation of the cement production line, and operation rate, reliability and security. While the 1st Generation Technical Solutions, neither puts the investment on the key equipments nor meets the requirement of large-scope fluctuation from the cement production line, nor has the same operation rate, reliability and security as the 2nd Generation Technical Solution due to too small heat-exchanging surface of HRSGs.

8.5 About Efficiency of Waste Heat Recovery Boiler

When the cement plant owner has some doubts on the heat-transferring surface of the boilers (the weight of the boilers) provided by the WHRPP supplier (or the boiler manufacturer), the WHRPP supplier (or the boiler manufacturer) usually explains these doubt by boiler heat-transferring surface efficiency or boiler thermal efficiency. But regarding the boilers used

Technical Guidance

- 43 -

for a WHRPP for a cement plant:

Firstly, the properties of the flue gas from the cement kiln (the temperature of the flue gas is low and the dust content is great) determines that various measures to improve the heat-exchanging efficiency of the heat-exchanging surface of the pipes inside the boiler are extremely limited, which means it will be unavailable substantially by the way of improving efficiency of the heat-exchanging of but decreasing the heat-exchanging surface (the weight) of the pipes inside the boiler;

Secondly, the flue gas from outlet of the waste heat boiler has to be recovered for cement production, therefore the heat exchanging efficiency for the waste heat recovery boiler as so called do not make any sense.

So, the technical specification to measure the waste heat recovery boiler normally are: flue gas temperature from the outlet of the waste heat recovery boiler, air leakage rate of the waste heat recovery boiler, flue gas resistance of the waste heat recovery boiler, temperature insulation protection outside the boiler wall, heat exchanging surface (weight) of the boiler, and so on.

Waste Heat Recovery Power Generation Engineering Technical Guidanceimg.tradekey.com/images/uploadedimages/brochures/9/0/... · 2011-05-31 · and power engineering, Mr. Tang began

Documents