Organic rankine cycle for exhaust waste heat recovery of a disel engine

1

ORGANIC RANKINE CYCLE FOR EXHAUST WASTE HEAT RECOVERY OF A DIESEL ENGINE

GUIDED BY PRESENTED BYSREEVATSAN RAMESH VIPIN MP ( AP, ME) ROLLNO:52 S7,ME

2

CONTENTS

• INTRODUCTION• WORKING PRINCIPLE• CONSTRUCTION OF ORC• WORKING FLUIDS• PERFORMANCE MAP OF THE DIESEL ENGINE• ADVANTAGES OF ORC.• EFFECT OF EVAPORATION PRESSURE.• EFFECTS OF EXHAUST TEMPERATURE .

3

INTRODUCTION

• Organic Rankine cycle(ORC) is a thermodynamic cycle which convert thermal energy into mechanical.

• ORC technology is similar to a traditional steam turbine.

• ORC generators are a way to convert waste heat into electricity.

• Internal combustion(IC) engines only convert about 40% of the total fuel combustion energy into useful work.

4

WORKING PRINCIPLE

• The ORC is a thermodynamic cycle that converts heat into work.

Figure 1: ORC VIDEO

5

CONSTRUCTION OF ORC

Figure-2 Schematic diagram of the ORC system

6

T-S diagram of the ORC system

Process 1-2 (Expander)🌕 Process 2-4 (Condenser)🌕 Process 4-5 (Pump)🌕 Process 5-1 (Evaporator)🌕

Figure-5

7

WORKING FLUIDS

• Water is the only working fluid for steam rankine cycle.

• Plenty of organic fluids are suitable for ORC.

WATER ORGANIC FLUIDSSmall, fast moving molecules Large flow rate

Metal parts and blade erosion No wear of blades and metal parts

8

CHOICE OF WORKING FLUID

• The selection of the working fluid is very important in ORC.• In order to recover low-grade heat, the fluid generally has a

lower boiling temperature than water.• Refrigerants and hydrocarbons are two commonly used

working fluids.

9

PROPERTIES OF WORKING FLUIDS

Figure-3 T-s diagram of the six selected working fluids

Table 1 Properties of the selected working fluids

10

EFFECT OF CRITICAL TEMPERATURE OF WORKING FLUIDS

• Net power output increases with increasing working fluids critical temperature

Figure-4

11

EFFECT OF EVAPORATION PRESSURE

• Power output increases with the evaporation pressure

Figure-6

12

PERFORMANCE MAP OF THE DIESEL ENGINE

• Exhaust energy of diesel engine varies with the operating conditions.

• Variation of the exhaust energy has an effect on the operating parameters of the ORC system.

(a) (b)

13

EFFECT OF EXHAUST TEMPERATURE

Figure-7

14

INSTALLATION COST

The ORC system will cost an estimated 2000-2500$/kW of installed capacity

15

ADVANTAGES OF ORC

• High turbine / thermodynamic cycle efficiency.• Turbine low mechanical stress.• No need to demineralize water.• No risk of blade erosion.• Non-oxidizing working fluid with no corrosion issues.• Completely automatic .• Simple maintenance procedure.• No operator attendance required.• Long life of the plant (> 20 years);.• Possibility to work at low temperatures (90+°C)

16

CONCLUSION

• ORC system is used to recover the exhaust waste heat from a diesel engine.

• Thermal efficiency and exergy efficiency are relative low.

• Power output increases with the evaporation pressure.

• Net power output increases with increasing working fluids critical temperature

17

REFERENCESFubin Yang, Hongguang Zhang, Songsong Song,Chen Bei, Hongjin

Wang,Enhua Wang “Thermoeconomic multi-objective optimization of an organic Rankine cycle for exhaust waste heat recovery of a diesel engine”. Energy 93(2015) 2208-2228.

Wolfgang Lang, Piero Colonna, Raimund Almbauer “Assessment of Waste Heat Recovery From a Heavy-Duty Truck Engine by Means of an ORC Turbogenerator”. Institute for Internal Combustion Engines and Thermodynamics, Graz University of Technology , inffeldgasse 21 , Graz,8010,Austria, APRIL2013,Vol,135/042313-1

Rongqi Shi, Tianqi He, Jie Peng, Yangjun Zhang, Weilin Zhuge “System design and control for waste heat recovery of automotive engines based on Organic Rankine Cycle ”State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing, China 0360-5442/©(2016) Elsevier Ltd