I Content 1. GENERAL ......................................................................................................................................................................... 1 2. SPECIFICATIONS ........................................................................................................................................................... 2 2.1 NOMENCLATURE............................................................................................................................................................... 2 2.2 PRODUCT LINE.................................................................................................................................................................. 2 2.3 SPECIFICATIONS................................................................................................................................................................ 3 2.4 APPLICATION LIMITS ....................................................................................................................................................... 4 3. CONSTRUCTION & FUNCTIONS ................................................................................................................................. 6 3.1 DESIGN FEATURES ............................................................................................................................................................ 6 3.2 CAPACITY MODULATION.................................................................................................................................................. 7 3.2.1 Step-type Control ............................................................................................................................................................... 8 3.2.2 Stepless Type Control ...................................................................................................................................................... 13 3.2.3 The Positions of Solenoid Valves .................................................................................................................................... 18 3.3 COMPRESSOR STARTUP LOADING & STOP UNLOADING................................................................................................. 19 4. LUBRICANT ................................................................................................................................................................... 20 4.1 LUBRICANT TABLE ......................................................................................................................................................... 20 4.2 OIL CHARGING ............................................................................................................................................................... 20 4.3 OIL CHANGE............................................................................................................................................................................ 21 4.3.1 Oil Change Schedule: ................................................................................................................................................ 21 4.3.2 Pre-cautions of Changing Oil .................................................................................................................................... 21 5. SYSTEM APPLICATION............................................................................................................................................... 22 5.1 PIPING DESIGN................................................................................................................................................................ 22 5.1.1 Suction and Discharge Piping Layout....................................................................................................................... 22 5.1.2 Economizer Piping Layout ........................................................................................................................................ 24 5.1.3 Minimum Pressure Valve .......................................................................................................................................... 25 5.1.4 Liquid Line Filter Dryer ............................................................................................................................................ 26 5.1.5 Sight Glass with Moisture Indicator.......................................................................................................................... 26 5.2 OIL LINE ......................................................................................................................................................................... 27 5.2.1 Oil Supply ................................................................................................................................................................... 27 5.2.2 Lubrication and Capacity Control Modulation......................................................................................................... 27 5.2.3 Compressor chamber injection cooling system ......................................................................................................... 28 5.2.4 Protection in Oil Line ................................................................................................................................................ 30 5.2.5 Oil Cooling System..................................................................................................................................................... 31 5.3 MOTOR LIQUID INJECTION COOLING ........................................................................................................................... 33 5.4 ECONOMIZER SYSTEM ................................................................................................................................................................... 35 5.4.1 Sub Cooler........................................................................................................................................................................ 35 5.4.2 Flash Tank ........................................................................................................................................................................ 36 5.5 RECOMMENDED SYSTEM LAYOUT ............................................................................................................................................ 37
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Transcript
I
Content
1. GENERAL ......................................................................................................................................................................... 1
2.2 PRODUCT LINE .................................................................................................................................................................. 2
3. CONSTRUCTION & FUNCTIONS ................................................................................................................................. 6
3.1 DESIGN FEATURES ............................................................................................................................................................ 6
3.2.1 Step-type Control ............................................................................................................................................................... 8
3.2.2 Stepless Type Control ...................................................................................................................................................... 13
3.2.3 The Positions of Solenoid Valves .................................................................................................................................... 18
4.3.2 Pre-cautions of Changing Oil .................................................................................................................................... 21
5. SYSTEM APPLICATION............................................................................................................................................... 22
5.1.4 Liquid Line Filter Dryer ............................................................................................................................................ 26
5.1.5 Sight Glass with Moisture Indicator .......................................................................................................................... 26
5.2 OIL LINE ......................................................................................................................................................................... 27
5.2.2 Lubrication and Capacity Control Modulation ......................................................................................................... 27
5.2.3 Compressor chamber injection cooling system ......................................................................................................... 28
5.2.4 Protection in Oil Line ................................................................................................................................................ 30
5.2.5 Oil Cooling System ..................................................................................................................................................... 31
5.3 MOTOR LIQUID INJECTION COOLING ........................................................................................................................... 33
5.4 ECONOMIZER SYSTEM ................................................................................................................................................................... 35
5.4.1 Sub Cooler ........................................................................................................................................................................ 35
5.4.2 Flash Tank ........................................................................................................................................................................ 36
5.5 RECOMMENDED SYSTEM LAYOUT ............................................................................................................................................ 37
II
6. MOTOR DESIGN ........................................................................................................................................................... 38
6.1 MOTOR PARAMETERS AND DESIGN ............................................................................................................................... 38
8.1.1 Check list before Start up ........................................................................................................................................... 47
8.1.2 Check list during operation ....................................................................................................................................... 48
10.1 ACCESSORY LIST ............................................................................................................................................................. 58
10.2 ACCESSORY FOR GAS REFRIGERANT LINE ..................................................................................................................... 59
10.5 OTHER ACCESSORY......................................................................................................................................................... 74
10.5.1 Mounting pad ........................................................................................................................................................ 74
1
1. General
For conventional single-stage screw compressors, the minimum evaporating temperature
is -40℃to -50℃ when they are used in refrigeration field, and the minimum ambient
temperature is -15℃ when applied to heat pumps. If you want to break this application
limitation, a compound two-stage compressor or multi unit of single stage compressors are
necessary. Meanwhile, the condition of high pressure ratio brings problems to the traditional
single stage compressors during compression process, such as excessive gas leakage and
exhaust temperature overheat etc., which leads to low efficiency and poor reliability when it
is working is such harsh condition.
While the single two-stage compressor well solves above problems. Compared to the
compound two-stage compressors and multi unit of single stage compressors, the single
two-stage compressors occupy less space and the system is easy to control, so it's more
efficiency and reliable.
The LT-S single two-stage low temperature type compressor can achieve
-60~-65℃evaporating temperature; the water outlet temperature of the LT-S-H single
two-stage high temperature type compressor can reach 90℃ when it is applied on water
source and ground source heat pump, which meet the heat demand of the radiator and other
industries and -40℃ when it is applied on air source heat pump, which greatly enlarge the
application field of the traditional air source heat pump. Because its energy efficiency ratio in
the low ambient temperature is higher, it's a perfect solution for haze governance and boiler
replacement.
For above reasons, Shanghai Hanbell Precise Machinery Co., Ltd. specialized in the
development of LT series two-stage screw refrigeration compressors which is composed of
two types: the semi-hermetic type (-S) and open type (-G). They can be used in the field of
low temperature refrigeration and high temperature heat pump according to the application.
High efficiency and reliability under big pressure difference and compression ratio working
condition is the main demand in design. It is a product of elite which accumulates Shanghai
Hanbell's rich technology and extensive application experience. LT can be widely used in low
temperature frozen products, frozen tunnels, freezers, process cooling, pharmaceutical
biochemistry, high temperature hot water, central heating and many other industries.
2. Specifications
2.1 Nomenclature
Figure 2-
2.2 Product Line
Figure
﹡NOTE: LT-XXXX includes LT-S/LT-
Disp
lace
men
t
m
3
/
h
-1. Nomenclature of LT Series Compressors
LT Series Compressor Displacement
Figure 2-2. LT Series Compressor Displacement
-S-H
2
3
2.3 Specifications
Model
Compressor
Low Stage High Stage Rotation
Speed
50Hz
r/min
Capacity Control
(Step type: ST)
(Stepless type: SL)
Lubrication
Type
Nozel Level
Displacement LT-S LT-S-H
50HZ 50HZ
m3/h m3/h ST SL
LT-20/10 224 99
2950
10%/50%
100% 10%~100%
Pressure
differential
80 81
LT-30/12 316 134 81 82
LT-45/20 450 207 83 84
LT-55/25 551 257 84 85
LT-65/32 651 313 10%/50%
75%/100%
86 88
LT-83/41 840 396 87 89
Model
Quality Motor
Pressure Test
Type Starting
Voltage
(V)
50HZ
Insulation Protection LT-S LT-S-H LT-S LT-S-H
Kg Bar
LT-20/10 598 620
3
phase
2 pole
Star
Delta 380 Level F
PTC+
PT100 35 15
LT-30/12 620 650
LT-45/20 1158 1200
LT-55/25 1195 1230
LT-65/32 1395 1450
LT-83/41 1430 1490
Figure 2-3.LT Series Compressor Specification
2.4 Application Limits
Co
nd
ensin
g T
emp
erature
Co
nd
ensin
g T
emp
erature
Figure 2-1. R22 Application Range
Figure 2-2. R404A Application Range
4
Co
nd
ensin
g T
emp
erature
Figure 2-3. R134a Application Range
5
6
3. Construction & Functions
3.1 Design Features
1) Unloading-type slide valve in high stage
Patented design, high voltage, automatic unloading VI blocking structure. The pure
mechanical structure design can simply & effectively realize the light loading of the
compressor without additional configuration of solenoid valves and other external
parts.
2) Check valve, shutoff valve and built-in economizer filter
Pre-install check valve, shutoff valve and economizer filter to realize the reliable
protection of the compressor and simplify customer's configuration system.
3) Optimized motor cooling path
Excellent design of the motor cooling path which cools down the motor coil reliably,
that enables the compressors to be used in wider range and enhanced the adaptability
of the compressor.
4) Pressure designed can meet high temperature application
The designed pressure is 36bar which meets the requirements of high temperature
application.
7
3.2 Capacity Modulation
The capacity modulation of LT series screw compressors has step type (3-step / 4-step)
and stepless type. Both of these two different capacity modulations work with the slide valve,
piston rod, cylinder, and piston. See below Figure 3-1.
When the slide valve is at the suction side completely, the screw rotors work with full
displacement under full load, at that time the compressor work volume is the maximum.
When the slide valve moves to the discharge side, the bypass occurs between the slide valve
and the suction side. The existing of the bypass results in the compressed gas of this range
bypassing to the low pressure directly, and the actual suction volume of the screw rotor
decreases. The more the sliding valve moves to the discharge side, the smaller the actual
suction capacity of the compressor will be, thereby reducing the system cooling capacity.
The slide valve is driven by the pressure difference among the internal capacity
modulation.
The lubricant comes from the external oil separator and passes through the oil filter then
enters into the oil inlet port of the compressor, and at last divided into both sides of the piston.
As a result, the piston can be controlled by discharge one side of the high pressure lubricant
to low pressure, letting it flow to the low pressure side so that the slide valve will move with
the piston to realize the loading and unloading of the compressor.
The purpose of the piston spring is to push the piston to its initial position (min. load
position), so as to realize the automatic unloading start. It not only reduces the mechanical
impact on the compressor's moving parts, but also reduces the electrical current during
compressor start up.
Stepless capacity control, solenoid valve(SV1:unloading, SV3:50%, SV5:100% ) is
controlled by a micro controller or a thermal switch to adjust the piston smoothly with stable
control of the cold output. If the oil filter in the capacity adjusting system, capillary or
solenoid valve don't work properly, it will cause the capacity adjusting system to be abnormal
and fail.
Figure 3-1 Capacity Modulation
8
3.2.1 Step-type Control
1) Step-type table
Y: Energize the solenoid valve N: Do not energize the solenoid valve
LT-83/41 &
65/32
Capacity
regulating
system
SV1:
(NC)
SV2:10%
(NC)
SV3:50%
(NC)
SV4:75%
(NC)
SV5:100%
(NC)
100% N N N N Y
75% Y N N Y N
50% Y N Y N N
10%
(Startup/Stop) Y Y N N N
LT-20/10
LT-30/12
LT-45/20
LT-55/25
Capacity
regulating
system
SV1:
(NC)
SV2:10%
(NC)
SV3:50%
(NC) /
SV5:100%
(NC)
100% N N N / Y
50% Y N Y / N
10%
(Startup/Stop) Y Y N / N
Table 3-1. Step-type Capacity Regulating Control Logic
2) Step-type capacity modulation diagram
Figure
3) Description of Step
� 10% load
capacity modulation diagram
Figure 3-2. Step-type capacity modulation
Description of Step-type control
Figure 3-3.10% Load
9
When starting up the compressor, SV1(unloading) & SV2 (10%) need
make the piston keep at the 10% position(Left side)
Under this situation, the high pressure oil passes through SV1 then goes to the right side
of the piston. At the same time, the oil in left side of the piston passes through SV2 (10%)
then going out to the low pressure side.
position.
★ Note: 10% load is for start up only. Running the compressor
recommended.
� 50% load
Under 50% load, SV1&SV3 (50%)
oil passes to the left side of the piston continuously. At the same time, the oil passes through
SV1 goes to the right side of the piston.
If the piston position is at the left side of the 50% hole (the loading is lower than 50%),
the oil in the right side of the piston will pass through SV3 (50%) and go out to the low
pressure side then the piston will move to right side until the position
It’s called loading to the 50% position.
Vice versa, if the piston position is at the right side of the 50% hole (the loading is higher
than 50%), the oil in the left side of the piston will pass through SV3 (50%) and go out to the
When starting up the compressor, SV1(unloading) & SV2 (10%) need
make the piston keep at the 10% position(Left side)
Under this situation, the high pressure oil passes through SV1 then goes to the right side
of the piston. At the same time, the oil in left side of the piston passes through SV2 (10%)
hen going out to the low pressure side. By doing so, the piston can be held at the 10%
p only. Running the compressor at 10% load for a long time is not
Figure 3-4.50% Load
1&SV3 (50%) are energized. Under this situation, the high pressure
oil passes to the left side of the piston continuously. At the same time, the oil passes through
goes to the right side of the piston.
If the piston position is at the left side of the 50% hole (the loading is lower than 50%),
the oil in the right side of the piston will pass through SV3 (50%) and go out to the low
pressure side then the piston will move to right side until the position b
It’s called loading to the 50% position.
Vice versa, if the piston position is at the right side of the 50% hole (the loading is higher
than 50%), the oil in the left side of the piston will pass through SV3 (50%) and go out to the
10
When starting up the compressor, SV1(unloading) & SV2 (10%) need to be energized to
Under this situation, the high pressure oil passes through SV1 then goes to the right side
of the piston. At the same time, the oil in left side of the piston passes through SV2 (10%)
doing so, the piston can be held at the 10%
at 10% load for a long time is not
energized. Under this situation, the high pressure
oil passes to the left side of the piston continuously. At the same time, the oil passes through
If the piston position is at the left side of the 50% hole (the loading is lower than 50%),
the oil in the right side of the piston will pass through SV3 (50%) and go out to the low
blocks the 50% hole.
Vice versa, if the piston position is at the right side of the 50% hole (the loading is higher
than 50%), the oil in the left side of the piston will pass through SV3 (50%) and go out to the
low pressure side then the piston will move to left until the position
called unloading to the 50% position.
� 75% load
Under 75% load, SV1&SV4 (75%)
The logic of 75% load is similar to th
75% hole to make the compressor run under 75% position.
pressure side then the piston will move to left until the position blocks the
called unloading to the 50% position.
Figure 3-5.75% Load
Under 75% load, SV1&SV4 (75%) are energized.
The logic of 75% load is similar to that of 50%. The piston can be held at the 75% position by
75% hole to make the compressor run under 75% position.
11
blocks the 50% hole. It’s
of 50%. The piston can be held at the 75% position by
� 100% load
Under 100% load, SV5 (100%)
passes to the left side of the piston continuously. At the same time, the oil in the right side of
the piston passes through SV5 (100%) then goes to the low pressure side to make the piston
be held at 100% position.
1) The control of the water temperature with step
★ Note: T & T' should be adjusted by system designer’s experience and practical application.
50%
Start
Set point + 2T
Set point + T
Set point
Set point– T'
100%
t1 t2
75% 10%
1~3
min
Condensing water temp.
Figure 3-6.100% Load
Under 100% load, SV5 (100%) are energized. Under this situation, the high pressure oil
to the left side of the piston continuously. At the same time, the oil in the right side of
the piston passes through SV5 (100%) then goes to the low pressure side to make the piston
The control of the water temperature with step type
Figure3-7. Water Temperature Control with Step Type
should be adjusted by system designer’s experience and practical application.
Stop
50% 75%
60~90 sec
12
energized. Under this situation, the high pressure oil
to the left side of the piston continuously. At the same time, the oil in the right side of
the piston passes through SV5 (100%) then goes to the low pressure side to make the piston
Water Temperature Control with Step Type
should be adjusted by system designer’s experience and practical application.
Time
Stop
10%
60~90 sec
3.2.2 Stepless Type Control
Stepless type is suitable when the refrigeration system needs to achieve precise control of
cooling capacity.
1) Stepless-type table
N: Do not energize the solenoid valve
LT Series
Capacity
regulating system
SV1:
(NC)
Loading N
Unloading Pulse active
Holding N
10% load
(Start/Stop) Stay active
Table 3-2. Stepless Type Capacity Regulating Control 50%~100%
2) Stepless-type capacity modulation diagram
Figure 3
is suitable when the refrigeration system needs to achieve precise control of
type table
Do not energize the solenoid valve
SV2:10%
(NC)
SV3:50%
(NC)
N N
Pulse active N Stay active
N N
Stay active Stay active N
2. Stepless Type Capacity Regulating Control 50%~100%
type capacity modulation diagram
Figure 3-8. Stepless-type capacity modulation
13
is suitable when the refrigeration system needs to achieve precise control of
SV5:100%
(NC)
Pulse active
N
N
N
2. Stepless Type Capacity Regulating Control 50%~100%
3) Description of Stepless
In stepless type control, the oil keeps going to the left side of the piston. The oil bypass
in the left side of the piston is controlled by SV
the piston is controlled by SV1 and oil bypass in the right side of the pisto
SV5 (100%). These three solenoid valves are controlled by temperature controller or PLC.
Through the three solenoid valve, the cooling capacity can be controlled at any position
from 50%~100%, so periodical adjustment of
stably.
★ Note: SV2(10%) can only be used for machine start and stop. Don't run the machine
at 10% loading for long time once the machine is started. It shall be switched to loading
model directly.
The stepless type capacity regula
controller(optional), eg. PLC etc. in order to control the system at the
� Loading
During loading process, the SV5 (100%)
valve are not activated. In this kind of situation, the
the piston continuously and the oil in the right side of the piston bypasses through SV5 (100%)
to the low pressure side. The piston
compressor will load.
Description of Stepless-type control
type control, the oil keeps going to the left side of the piston. The oil bypass
s controlled by SV3 (50%). The oil charging in the right side of
the piston is controlled by SV1 and oil bypass in the right side of the pisto
SV5 (100%). These three solenoid valves are controlled by temperature controller or PLC.
Through the three solenoid valve, the cooling capacity can be controlled at any position
from 50%~100%, so periodical adjustment of SV1、SV3、SV5 can control the energy output
SV2(10%) can only be used for machine start and stop. Don't run the machine
at 10% loading for long time once the machine is started. It shall be switched to loading
The stepless type capacity regulating system shall be connected to the micro
etc. in order to control the system at the 6
Figure 3-9. Loading
he SV5 (100%) adopts pulse activation, and the
valve are not activated. In this kind of situation, the high pressure oil goes into the left side of
the piston continuously and the oil in the right side of the piston bypasses through SV5 (100%)
to the low pressure side. The piston will continue to move to the right side and the
14
type control, the oil keeps going to the left side of the piston. The oil bypass
0%). The oil charging in the right side of
the piston is controlled by SV1 and oil bypass in the right side of the piston is controlled by
SV5 (100%). These three solenoid valves are controlled by temperature controller or PLC.
Through the three solenoid valve, the cooling capacity can be controlled at any position
control the energy output
SV2(10%) can only be used for machine start and stop. Don't run the machine
at 10% loading for long time once the machine is started. It shall be switched to loading
ting system shall be connected to the micro
6
and the rest solenoid
high pressure oil goes into the left side of
the piston continuously and the oil in the right side of the piston bypasses through SV5 (100%)
to the right side and the
� Unloading
During unloading process, t
and the rest solenoid valve are not activated. T
continues to inject into the left side of the piston &
right side of the piston. Through SV3(50%), it bypasses to the low pressure side, so that the
piston continues to move to the lift side, an
Figure 3-10. Unloading
During unloading process, the SV2(50%) stays active, and SV1 adopts pulse activation
rest solenoid valve are not activated. The high pressure oil coming from the oil tank
into the left side of the piston & passes through SV1 and goes into the
Through SV3(50%), it bypasses to the low pressure side, so that the
piston continues to move to the lift side, and the compressor will load to 50% piston.
15
and SV1 adopts pulse activation ,
coming from the oil tank
passes through SV1 and goes into the
Through SV3(50%), it bypasses to the low pressure side, so that the
d the compressor will load to 50% piston.
� Holding
During this process, all S/V are not energized.
tank continues to inject into the left side of the piston. The left side oil inlet of the piston
SV1and SV5(100%) are closed to keep the oil amount in the piston right side. The piston will
not be able to move and stay at its original position, so that the compressor capacity wil
change as well.
� The control of the water temperature with stepless type
Below picture shows load control model of single compressor using stepless type capacity
regulation.
Chilled water temp.
Figure 3-11. Holding
, all S/V are not energized. The high pressure oil coming from the oil
into the left side of the piston. The left side oil inlet of the piston
to keep the oil amount in the piston right side. The piston will
not be able to move and stay at its original position, so that the compressor capacity wil
The control of the water temperature with stepless type
load control model of single compressor using stepless type capacity
Figure 3-12 Stepless Capacity Regulation
16
The high pressure oil coming from the oil
into the left side of the piston. The left side oil inlet of the piston
to keep the oil amount in the piston right side. The piston will
not be able to move and stay at its original position, so that the compressor capacity will not
load control model of single compressor using stepless type capacity
12 Stepless Capacity Regulation Time
★ Note:X′ : Upper Limit;X〞:Lower Limit
� Description
� The real value is larger than the top line between A & B. It means the required cooling
capacity is increasing and the compressor needs to be loaded until the
the control range.
� The real value is smaller than the bottom line between C & D. It means the required
cooling capacity is decreasing and the compressor needs to be unloaded until the real
value returns to the control range.
Figure 3-13 Solenoid Valve Action Intervals
★ Note:For detail stepless type capacity regulation control logic, please refer to Table 3
Load/Unload functions between A and B & C and D.
� Open means S/V is energized
� Close means S.V is not energized
� T1,T3:Pulse time 0.5~1.5seconds
� T2,T4:Pause time 10~20seconds
:Lower Limit;X:Set Point;H: Control Range;
The real value is larger than the top line between A & B. It means the required cooling
capacity is increasing and the compressor needs to be loaded until the
The real value is smaller than the bottom line between C & D. It means the required
cooling capacity is decreasing and the compressor needs to be unloaded until the real
value returns to the control range.
13 Solenoid Valve Action Intervals-Stepless type
For detail stepless type capacity regulation control logic, please refer to Table 3
Load/Unload functions between A and B & C and D.
Open means S/V is energized
Close means S.V is not energized
Pulse time 0.5~1.5seconds
Pause time 10~20seconds
17
;Y:Actual value
The real value is larger than the top line between A & B. It means the required cooling
capacity is increasing and the compressor needs to be loaded until the real value returns to
The real value is smaller than the bottom line between C & D. It means the required
cooling capacity is decreasing and the compressor needs to be unloaded until the real
Stepless type
For detail stepless type capacity regulation control logic, please refer to Table 3-2
3.2.3 The Positions of Solenoid Valves
1. LT-65/32, LT-83/41
Figure
2. LT-20/10, LT-30/12, LT
Figure 3-15 LT
3.2.3 The Positions of Solenoid Valves
Figure 3-14 LT-83/41<-65/32 S/V position
LT-45/20, LT-55/25
LT-20/10<-30/12<-45/20<-55/25 S/V position
18
S/V position
3.3 Compressor startup loading
To decrease the mechanical loading to compressor’s parts and
during start up. Hanbell designs for LT compressor the function of unloading startup. To