steam powered absorption chiller installation and operation manual tt

Thermal Technologies Europe AB | www.thermatec.se | [email protected]

Steam-fired LiBr Absorption ChillerInstallation & Operation Manual

V5.1

Contents Part 1 Working Conditions ............................................................................................................................. 1 Part 2 Working Principle and Cooling cycle .................................................................................................. 2 Part 3 Main Parts and Their Functions ........................................................................................................... 4 Part 4 Properties of LiBr Solution .................................................................................................................. 6 Part 5 Control System and Protections........................................................................................................... 8 Part 6 Installation of system ......................................................................................................................... 13 Part 7 Preparation and Operation ................................................................................................................. 16 Part 8 Operation Record and Management .................................................................................................. 23 Part 9 Troubleshooting ................................................................................................................................. 27 Part 10 Maintenance .................................................................................................................................... 31 Appendix 1Saturated water vapor temperature & pressure table ............................................................ 37 Appendix 2System diagram .................................................................................................................... 38 Appendix 3Solubility curve of LiBr solution .......................................................................................... 39 Appendix 4Users water system linkage diagram ................................................................................... 40 Appendix 5Control cabinet I/O terminals ............................................................................................... 41 Appendix 6Electrical principle diagram ................................................................................................. 42

Thermal Technologies Europe AB | www.thermatec.se | [email protected]

1

Part 1 Working Conditions

Chilled water outlet temperature: 5

Cooling water inlet temperature: 1834

Chilled/Cooling water system pressure: 0.8MPa (except special orders)

Cooling water: Clean fresh water, with its quality complying with Table 8-1

Working steam: Saturated vapor with dryness fraction>99% and overheating

degree20C (except other vapors specified in the contract)

Power supply: 3 phase, 380V/50Hz

Machine room temperature: 5C40C

Machine room relative humidity: 85%

Machine room should be free of dust

Warning: 1. The chiller is a type of vacuum equipment and all valves on it have been

firmly sealed before shipment from factory. Any forms of modification to these valves are prohibited, that may damage or even destroy the chiller.

2. The chiller should be stored at a place where it is protected from rain and the relative humidity is not greater than 85%, otherwise the electrical elements may be damaged.

3. The chiller should be unpacked only by our companys professional commissioning personnel or properly trained individuals.

4. Do install a strainer (60-80 meshes) at the steam inlet. 5. Do install a check valve at the steam inlet. 6. The customers chilled water pump and cooling water pump are required to

be in linkage with the chiller, otherwise the freezing of tubes may occur.

Thermal Technologies Europe AB | www.thermatec.se | [email protected] p. 1

2

Part 2 Working Principle and Cooling cycle

1. Working principle

Any liquid absorbs heat from its surroundings as it vaporizes. And the lower the

atmospheric pressure, the lower the vaporizing temperature. For example, water vaporizes at

100 under one atmospheric pressure, but under the 0.00891 atmospheric pressure, it

vaporizes at 5.

That is the basic working principle of a LiBr absorption chiller. Water (the refrigerant)

vaporizes in the high-vacuum absorber and absorbs heat from the water to be chilled. The

refrigerant vapor is then absorbed by the LiBr solution (the absorbent) and circulated by pumps

to keep the process going cyclically.

Fig.2-1 Working principle

2. Cooling cycle

The working principle of a steam-fired double-effect LiBr absorption chiller is shown as

Figure 2-1. The diluted solution from the absorber, pumped by the solution pump, passes the

low-temperature heat exchanger (LTHE), condensed water heat exchanger (CWHE) and

6FF54F

F3

F2

1F

1

2

3

4

5

6

7

8

5 4

8

7

6 3

2

1Cooling water

out

Chilled water out

Cooling water in

Chilled water in

CondenserLow-temp generator

Steam in

High-temp generator

Evaporator Absorber

High-temp generator pressure

High-temp generator intermediate solution temp

Automatic decrystallizing tube temp

Evaporator liquid levelEvaporation temp

Automatic purge device liquid level

Cooling water inlet tempCooling water inlet target flowmeter

Chilled water inlet tempChilled water inlet target flowmeter

Chilled water outlet tempChilled water outlet target flowmeter

F1 Main purge valveF2 Ultimate vacuum purge valveF3 Absorber purge changeover valveF4 Refrigerant water sampling valveF5 Solution sampling valveF6 Refrigerant water regereration valve

Condensate out

Steam trap

Condensate heat exchanger

Low-temp heat exchanger

Auto

mati

c de

crys

talliz

ing t

ube

High-temp heat exchanger

Aut

omati

c pu

rge d

evice

Cooler

Vacuum pump Refrigerant pump

Solution pump

Oil trap

Concentrated solution

Intermediate solution

Diluted solution

Chilled water Cooling water

Refrigerant water

Refrigerant vapor

Steam

Condensate


3

high-temperature heat exchanger (HTHE) and enters the high-temperature generator (HTG),

where it is boiled by the working steam flowing in the tubes to generate high-pressure,

high-temperature refrigerant vapor. The diluted solution turns into the intermediate solution.

The intermediate solution flows via HTHE into the low-temperature generator (LTG),

where it is heated by the refrigerant vapor from HTG to generate refrigerant vapor. The

intermediate solution becomes the concentrated solution.

The high-pressure, high-temperature refrigerant from HTG, after heating the intermediate

solution in LTG, condenses into refrigerant water. The refrigerant water then, together with the

refrigerant vapor from LTG, enters the condenser, where the mixture is cooled by the cooling

water and turns into refrigerant water.

The refrigerant water generated in the condenser passes through a U-pipe and enters the

evaporator. Part of the refrigerant water vaporizes due to the very low pressure in the

evaporator, while the majority of it is pumped by the refrigerant pump and sprayed on the

evaporator tube bundle. The refrigerant water sprayed on the tube bundle then absorbs the heat

from the water flowing in the tube bundle and vaporizes.

The concentrated solution from LTG flows via LTHE into the absorber and is sprayed on

the tube bundle. After being cooled by the water flowing in the tube bundle, the concentrated

solution absorbs the refrigerant vapor from the evaporator and becomes diluted solution. In this

way, the concentrated solution continuously absorbs the refrigerant vapor generated in the

evaporator, keeping the evaporation process continuing. In the meantime, the diluted solution is

transmitted by the solution pump to HTG, where it is boiled and concentrated again. Thus a

cooling cycle is completed and the cycle repeats.


4

Part 3 Main Parts and Their Functions

The steam-fired double-effect LiBr absorption chiller mainly consists of the

high-temperature generator (HTG) (not available for single-effect models), low-temperature

generator (LTG), condenser, evaporator, absorber, high-temperature heat exchanger (HTHE)

(not available for single-effect models), low-temperature heat exchanger (LTHE), condensed

water heat exchanger (CWHE)automatic purge device, vacuum pump, solution pump,

refrigerant pump, electric valve, electric control cabinet, etc.

Table 3-1

S/N Part Name Function

1 HTG

Boils the solution with the working steam to generate the primary refrigerant

vapour which will enter LTG and concentrates the solution into the

intermediate solution which will flow to HTHE.

Working condition: absolute pressure700mmHg

solution temperature155C

2 LTG

Utilizes the primary refrigerant vapour to concentrate the intermediate

solution into concentrated solution. The primary refrigerant vapour changes

into refrigerant water and the secondary refrigerant vapour is created.

For a single-effect model, LTG evaporates the solution with the working

steam to generate the refrigerant vapour, and the solution becomes

concentrated solution.


solution temperature90C

3 Condenser

Condenses the refrigerant vapour from LTG into refrigerant water and cools

down the primary refrigerant water from HTG, with the heat generated taken

away by the cooling water.

Working condition: absolute pressure55mmHg.

4 Evaporator Evaporates the refrigerant water to cool down the chilled water.


5 Absorber Uses the concentrated solution to absorb the refrigerant vapour from the

evaporator, with the heat being taken away by the cooling water.

6 HTHE Recovers heat from the intermediated solution in HTG, improving the

thermodynamic coefficient of the chiller.


5

7 LTHE Recovers heat from the concentrated solution in LTG, improving the

thermodynamic coefficient of the chiller.

8 CWHE Recovers heat from the condensate of the working steam in HTG, improving

the thermodynamic coefficient and lowering the steam consumption of the

chiller.

9 Automatic

purge device They constitute the purge system which removes the non-condensable gas in

the chiller, guaranteeing the performance and extending the service life of the

chiller. 10 Vacuum pump

11 Refrigerant

pump

Circulates the refrigerant water, making it dispersed evenly on the heat

transfer tube bundle in the evaporator.

12 Solution pump Circulates the solution.

13 Electric valve

set

Regulates the input of working steam or cuts off the working steam

14 Electric control

cabinet

Accommodates components of the control system.


6

Part 4 Properties of LiBr Solution

1. General properties

Lithium bromide (LiBr) is similar to sodium chloride (NaCl) in property. As a stable

substance, it is nonperishable, non-decomposable and nonvolatile in the atmosphere. Its

solution is a clear, transparent, and nontoxic liquid, which has a bitter taste and can cause slight

itching on the skin. LiBr solution becomes slight yellow after lithium chromate (Li2CrO3) is

added in, and remains clear with lithium molybdate (Li2MoO4). Avoid touching it directly with

skin, splashing it into eyes and tasting it.

The quality of the LiBr solution decides the chiller performance to a large extent.

Therefore, strict measures must be taken to control its quality, which should meet the following

standards:

Concentration: 500.5%

Alkalinity: pH 9.0~10.5

Li2CrO3 content: 0.10.3% ( Li2MoO4 content: 0.012~0.018%) Maximum content of impurities:

ChlorideCl-: 0.05%

SulphateSO4-: 0.02% BromateBO4-: non-reaction

AmmoniaNH3: 0.0001%

BariumBa: 0.001% CalciumCa: 0.001%

MagnesiumMg: 0.001%

2. Solubility

The concentration of the saturated LiBr solution is about 60% at normal temperature. At a

given concentration, crystals separate out from the solution when the temperature drops. And at

a given temperature, crystals separate out when the concentration rises. Crystallization must

be avoided during the chillers operation and shutdown period. See Appendix 3 for the

solubility curve of LiBr solution.

3. Specific gravity

The specific gravity of LiBr solution is greater than that of water and is a function of the

concentration and temperature of the solution itself. So once the specific gravity and


7

temperature of the solution is measured, the concentration can be obtained.

4. Causticity

Though LiBr solution has little caustic effect on common metals under vacuum condition,

it causes severe corrosion with presence of an extremely little amount of oxygen within the

chiller. Therefore, preventing air leaking into the chiller is the fundamental measures for

anti-corrosion. Adding proper amount of Li2CrO3(Li2MoO4) in the LiBr solution and keeping

pH value at 9.0~10.5 also effectively reduces its caustic effect on metals.


8

Part 5 Control System and Protections

1. Components of control system

The control system of the chiller is composed of the PLC, touch screen, inverter,

temperature acquisition module, analog output module, liquid level controller, AC contactor,

thermal relay, intermediate relay, etc. Its peripheral input sensors include target flow switch,

liquid level electrode, platinum resistor, pressure switch, etc.

2. Functions of control system

S/N Function Description

1 Touch screen

operation

Easy and reliable touch operation compared to mechanical

contacts.

2 Human-machine

dialogue

Customers can change the parameter settings, correct the

measured values of parameters, learn how to operate and

maintain the chiller and have access to the memory through the

human-machine interface.

3 Clock display Time can be displayed on the screen, including the year, month,

date, hour, minute, second and weekday.

4 Auto start/stop The chiller can be automatically started or stopped at the

customer set time.

5 Information display Information about the chiller operating status, parameter setting,

correction, etc. is displayed in different pages on the screen.

6 Real-time test and display

Parameters such as temperature, flow and liquid level are

monitored and displayed in real-time mode.

7 Password protection

Three-level password protection system (power-on password,

parameter correction password and parameter setting password)

prevents unauthorized operations.

8 Auto load-adjusting

When the load varies, the steam input and circulating solution

amount are automatically controled, making the chiller operating

at the best status.


9

9 Solution pump

inverter control

The solution pump is controlled by an inverter, ensuring

optimum circulating amount of the solution and optimum liquid

level in HTG.

10 Interlock control

system

The chilled water pump, cooling water pump and cooling tower

fan are automatically started or stopped according to the

operating condition, thus realizing automatic control throughout

the air conditioning system.

11 Fault protection and alarm

Once a fault occurs in the water system or the chiller itself, the

degree of the fault is automatically identified, an alarm is given

and corresponding protective measures are taken.

12 Self-diagnosis Faults are automatically diagnosed. Their location, cause and

remedy are suggested.

13 Fault record Information about faults, such as occurring time and type, is

stored automatically.

14 Remote control (extended function)

Control and monitoring of the chiller can be conducted from a

remote place and or via a DCS/PLC system.

15 Telephone networking (extended function)

Various data can be transmitted via the telephone network. Our

company can learn about the operation status of customers units

at any place by telephone, thus achieving active after-sale

service.

16 Building interface (extended function)

Reserved interface, used for linking with the building control

center.


10

3. Operation sequence of the AI (artificial intelligence) system

Close air switch K1

Close air switch K2

Input power-on password

Function selection menu

Chiller function selection

Operation mode selection

Auxiliary function selection

Coo

ling

Aut

o ru

n

Man

ual r

un

Tim

ed o

pera

tion

Rem

ote

cont

rol

Con

trol p

aram

eter

cor

rect

ion

Con

trol p

aram

eter

setti

ng

Faul

t man

agem

ent

Syst

em fu

nctio

n

Ope

ratio

n re

cord

retri

eval

Auto run (cooling)

Cooling + auto run

Manual run (cooling)

Cooling + manual run

Timed operation (cooling)

Cooling + timed operation

Remote control (cooling)

Cooling + remote control


11

4. Safety protection functions

Note: A single-effect absorption chiller doesnt have the long-time low liquid level fault in

HTG, high-pressure fault in HTG and false liquid level fault in HTG.

Power supply phase loss or phase reversed

Solution pump or inverter fault

Long-time low liquid level fault in HTG

High-pressure fault in HTG

Low-temp fault of chilled water

Stop of chilled water supply

Chilled water flow sensor fault

Stop of cooling water supply

Cooling water flow sensor fault

Refrigerant pump fault

False liquid level fault in HTG

High-temp fault in HTG

Evaporation low-temp fault

Cooling water high-temp fault

Cooling water low-temp fault

De-crystallizing tube high-temp fault

Chilled water inlet-outlet temp difference overlarge fault

Chilled water inlet temp sensor fault

Chilled water outlet temp sensor fault

Evaporating temp sensor fault

Cooling water temp sensor fault

HTG temp sensor fault

De-crystallizing tube temp sensor fault

Vacuum pump fault

Chiller stops, with alarm

If faults occur during auto/manual run, the chiller switches to dilution operation, with alarm

This function doesnt affect the control of the chiller.

If faults occur during auto run, the chiller switches to dilution operation. If faults occur during manual run, these functions dont affect the control of the chiller. In both cases, alarm is given


12

5. Main parameter settings

AI system is an intelligent control system, which collects the real-time operating data about

the customer system and the chiller itself and adjusts the steam input and the circulating

amount of the solution based on the data. The default settings of the parameters listed below

may be reset by users as required.

Table 5-1

S/N Parameter name Default setting Setting range

1 Cooling water outlet temp 7C 620C

2 Temp difference between cooling water

inlet and outlet temp 5C 510C

3 HTG temp(cooling) 160C (98C for

singe-effect models)

145~160C (90~101C for

singe-effect models)

4 Pressure of pressure controller 0.02MPa Change prohibited

5 Inverter highest operating frequency 50Hz 40 50Hz (non-settable for

certain models)

6 Power-on password 1 09999

7 Parameter setting password **** 09999

8 Parameter correction password **** 09999

Parameter setting procedure

Input the power-on password and parameter setting password, enter the parameter

setting menu and set the parameter.

For safe operation purpose, parameters should be set by professional technicians!

6. Grounding requirement

To ensure safe and reliable operation of the chiller, the chiller is required to have a special

ground pole with the grounding resistance not greater than 10. The grounding terminals of the chillers electrical devices should be securely connected to this pole. Without a special

ground pole (or a neutral line), the chiller may be damaged and people be injured.


13

Part 6 Installation of system

1. Machine room

Try to select a machine room which is close to the steam source and to where the

chilled water is used.

The machine room should have enough brightness and good ventilation with the relative humidity less than 85%. In case the chiller is installed outside the room, the

electrical devices and measuring instruments should be protected from moisture, rain,

sunshine, etc.

Sufficient space should be reserved around the chiller for maintenance: 1m in the

lengthwise direction, 0.2m above the chiller, 1.2m on the control cabinet side and

0.5m on other sides. And on either end of the chiller, a tube-drawing apace, not less

than the distance between the two tube sheets, should be kept so that the heat transfer

tubes can be drawn out.

The machine room should be equipped with necessary devices like electric outlets and water taps. And there should be drains around the chiller.

2. Placement of chiller

Since the LiBr absorption chiller runs stably

with slight vibration, its foundation may be

designed according to its static load (i.e. operating

weight)

After putting the chiller in place, calibrate the

chiller horizontally with the help of the 4 basic

holes in the two tube sheets. The error of the level

degree should not be greater than 0.002. The level

degree can be regulated through the cushion block

located between the foundation and the support of

the chiller and can be measured with a gradient or a

transparent plastic connecting pipe.

Basic holes

Wat

er-f

illed

pla

stic

pip

e


14

3. Piping

Flexible connectors and manometers should be mounted at the inlets/outlets of the chilled

water and cooling water. If the dryness of the working steam is less than 0.90, a steam-water

separator should be mounted. At the inlets of chilled and cooling water there should be

strainers with 3-6mm meshes, or the cooling capacity may decrease and frozen tubes may

occur. And at the inlet of the working steam, there should be a strainer with 60-80 meshes,

otherwise failure in the electric valve may occur.

The steam piping is suggested as below:

In certain cases the steam supply cannot be cut off suddenly, for it may affect the

production process or the system. In such cases, replace the motorized two-way valve with a

three-way valve (as shown below).

4. Steam condensate piping

The pressure of the steam condensate usually stands at 0.05MPa. If the condensate cannot

return to the boiler room by itself, install a condensate tank at the condensate exit and then

Steam

Steam piping diagram(for reference)

Strainer(80-100 meshes)


Cut-off valve

Cut-off valve

Cut-off valve

Pressure reducing

valve

Electric valve

Pipe reducer

HTG end enclosure

Steam

Cut-off valve

Cut-off valve

Cut-off valve



Pressure reducing

valveElectric valve

Pipe reducer

HTG end enclosure

to cooling equipment when the chiller stops

3-way steam valve piping diagram(for reference)


15

pump the condensate to the boiler room. The condensate tank should be lower than lowest

place of HTG. The weight of all external pipes connected to the chiller must be carried by

the chiller!


16

Part 7 Preparation and Operation

1. Preparation for initial start

Preparation of instruments and tools: Hand tools

Absolute pressure gauge

Digital multi-meter Liquid-charging flexible pipe: diameter 1 inch25mmlength 6m.

Densi-meter and mercury thermometer

Check of jobsite piping Check the chilled/cooling water pipes according to the Piping system diagram

Check if the inlets/outlets of the water system, water pumps and cooling tower are

misconnected;

Check if there is a discharge valve on each pipeline;

Check if there is leakage at flanged connections;

Make sure the chilled/cooling water flow rate meets the operation requirement and check the pressure borne by the chiller water system;

A hand-operated cut-off valve and pressure reducing valve should be installed on the

steam pipe;

Check if a drain valve has been installed at the lowest site of both the steam pipe and

the steam condensate pipe.

Check of purge system Check if the vacuum pump oil brand number is correct;

Check if the vacuum pump oil has been emulsified and the oil level is in the middle of

the sight glass;

Check the ultimate vacuum of the vacuum pump: close the main purge valve F1, start

the vacuum pump and pump the oil trap only. Connect a McLeod vacuum gauge to the

ultimate vacuum purge valve F2, start the vacuum pump and let it run for 3-5 minutes.

If the reading on the McLeod vacuum gauge is consistent with the ultimate vacuum of

the pump, that indicates the vacuum pump is excellent in performance.

Check of wiring All system equipment is required to be checked.

Check if the wiring complies with the Wiring diagram and meets the requirement.

Check if the power supply for the cooling tower fan/chilled water pump/cooling water pump is correctly connected.


17

Check if the voltage and frequency of the power supply match the motor nameplate parameters and meet the requirements of the control system.

Check the permitted overload capacity and fuse size of each motor.

Check if all electrical devices have been earthed as required. During operation, check if all motors lubrication, power supply and rotation direction

are normal.

Do not start the solution pump or refrigerant pump before the LiBr solution is fully

charged into the chiller. Otherwise, the pump will be seriously damaged. Charging of LiBr solution

The LiBr solution is generally a 50% mixed solution, in which 0.2% lithium chromate (or

0.015% lithium molybdate) has been added as a corrosion inhibitor. The pH value of the

solution has been adjusted within the range of 9~10.5. It is recommended to recheck the

solution and take a sample and reserve the sample prior to the charging.

Charging principle The solution is sucked into the absorber by the high vacuum in the chiller sucks via the

sampling valve (F5) located at the solution pump outlet.

Attention points a) Do not start the solution pump while charging the solution.

b) Do not charge the solution directly from a small container into the chiller. That may

bring air into the chiller.

c) When the charging begins, start the vacuum pump to

remove non-condensable gases out of the chiller.

Charging method Prepare a solution container (made of corrosion

resistant material), pour the solution in it(if solution is turbid

or dirty, filter it first), and connect as the figure on the right.

Fill the flexible pipe with solution to keep air out. Connect

one end of the pipe with the sampling valve, and dip the other end in the container. Notice:

keep the flexible pipe filled with water to prevent air entering; and the end dipped in the

container should be at least 30mm away from the bottom of the container lest the deposits and

impurities flow into the chiller with the solution.

Charging amount Refer to the nominal parameter table for the charging amount of the solution. Whether

Flexible pipe

Solution container

Sampling valve


18

the amount is appropriate can be judged by observing if it meets the circulating requirement of

the chiller under the standard operation condition.

2. Operation of the chiller

Manual run screen

Manual run procedure

a) Start the chilled water pump and open its discharge valve, and regulate the flow rate to

the rated valve;

b) Start the cooling water pump and open its discharge valve, and regulate the flow rate to

the rated value;

c) Open the hand-operated steam valve and condensate drain valve, drain the condensate

water in the steam supply pipe, and regulated the steam pressure to the rated value.

d) Turn on the power switch in the control cabinet. The start-up menu is displayed on the

touch screen. Press Power-on password key, input the pre-set power-on password,

press Confirmation and then enter the Manual run menu following the prompts on

the screen;

e) Press Chilled water pump, Cooling water pump, Solution pump and Refrigerant


19

pump keys(highlighted after pressed) in sequence. Start the electric valve slowly. The

chiller enters normal operation. When the screen indicates that the cooling water inlet

temperature is equal to or greater than 30, start the cooling tower.

f) Stop procedure: Close all valves first. The chiller starts the dilution operation. Wait until

the temperature of the solution at the HTG exit drops below 80, stop the Solution

pump, Refrigerant pump, Cooling water pump and Chilled water pump in

sequence. Press Back key in the upper right corner of the screen returning to the

start-up menu, then switch off the control power supply.

Function of other touch keys

Vacuum pumpUsed to start the vacuum pump

Alarm silenceUsed to eliminate the fault warning sound temporarily

Solution pump frequencyUsed to display the frequency of the current voltage

HTG levelUsed to display the HTG liquid level, which can be regulated by changing

the frequency of the inverter

Right part of screen: Used to display main operating parameters

Manual run of the chiller is only for commissioning and must be performed by

professional personnel!

To prevent the heat transfer tubes in the evaporator from being frozen due to stop of

cooling water flow, observe the following items:

Confirm that the target flow switch works normally before starting the chiller.

When starting the chiller, start the chilled water pump (and confirm it has run)

first and then the cooling water pump.

After dilution and shutdown, stop the cooling water pump first and then the

chilled water pump.


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Auto run screen

Auto run procedure

a) Enter the function selection menu and select Auto run.

b) Press the Auto start key. The chilled water pump, cooling water pump, solution pump,

electric valve and refrigerant pump are started in sequence. If any fault occurs, the

chiller begins dilution operation and gives an alarm and the screen automatically

switches to the fault management menu, which provides information about the fault and

its treatment.

c) Stop procedure: Press the Auto stop key and the chiller begins the dilution operation.

Once the HTG temperature drops to the pre-set value, the chiller stops automatically.

Then stop the cooling water pump, and two minutes later stop the chilled water pump

and turn off the power supply to the chillerwhen the chilled water pump and cooling

water pump are not interlocked with the chiller.

Note: Solution pump, Refrigerant pump, Electric valve, Chilled water pump, Cooling

water pump, and Cooling tower are used only for display. They cannot be operated.


21

The frequency of the solution pump has been set in the factory, no people other than

professional technicians is permitted to modify it!

Close the steam cut-off valve first after the chiller is stopped (whether automatically

or manually), otherwise hazardous faults such as crystallization in HTG or high pressure

may occur.

5. Purging

In cooling cycle

In cooling operation, purge valves 1 and 2 are closed.

When the liquid level in the gas tank falls below the

sight glass or the control cabinet operation panel requires,

the vacuum pump should be started for purging. Purging

steps are:

1) Start the vacuum pump and keep it running for about half a minute;

2) Open valve 1 and pump for at least three minutes;

3) Open valve 2 and keep pumping until the cooling effect recovers;

4) Close valve 1 first and then valve 2;

5) Let the vacuum pump run for another half an hour, and then stop it.

Attention: If valve 2 is not closed, non-condensable gases in the gas tank will return to the inside of the chiller through it.

In shutdown period During a long period of shutdown, the purging should be performed once every month,

each time for about one hour. The method is: start the vacuum pump and open valves 1 and 2.

After purging, close valve 1 first and then stop the vacuum pump and close valve 2, otherwise

the vacuum pump oil will be pumped into the chiller and degrade the cooling performance

greatly.

The chiller must be kept highly airtight and the air in it must be pumped out timely,

1

2

Purge valve 1

Purge valve 2

Sight glass

Vacuum pump

Gas

takn

Solu

tion

in

Oil trap

Ejector


22

otherwise the life of the chiller will be shortened and the energy consumption increased dramatically!

Replacement of diaphragms

1) The diaphragms of valves 1 and 2 must be replaced every 3 years.

2) Other valve diaphragms must be replaced every 5 years.

Maintenance of the vacuum pump

1) If a water layer emerges at the bottom of the vacuum pump oil, drain it out slowly. During the pumping of the vacuum pump, the gas ballast valve on it should be left

open so that the water vapor can be removed out of the pump.

2) If the vacuum pump oil is emulsified and turns white, replace it.

Secondary seal for the vacuum valve

Sealing rings wear out due to the rotation of the valve shaft, which in turn will cause gas

leakage; therefore, great attention should be paid to the secondary seal.

1) Remove the oil stains, scrap iron and sealant residues on the valve cap screw thread,

valve body screw thread and O-rings with a steel brush;

2) Spray Letai detergent on them, brush again and dry them;

3) Spread a layer of Letai 567 sealant for pipe thread;

4) Tighten the valve cap with a spanner to secure the seal.


23

Part 8 Operation Record and Management 1. Operation record form

The operation record is an important document to track the operation status of the chiller.

It is usually recorded at an interval of 1 to 2 hours, which may be longer or shorter as

required.

Operation Record Form for Steam-fired Chillers Model or S/N Date Recorder

Recording items Time

Unit

Evaporator Chilled water

inlet temp

Chilled water

outlet temp

Evaporation

temp

Chilled water

inlet pressure

MPa

Chilled water

outlet pressure

MPa

Chilled water

flowrate

m3/h

HTG Steam

consumption

Kg/h

Steam temp

Steam pressure kPa

Solution temp at

HTG outlet

Condensate

discharge temp

HTHE Intermediate

solution outlet

temp

Diluted solution

outlet temp

LTHE Diluted solution

inlet temp

Concentrated

solution inlet

temp


24

Concentrated

solution outlet

temp

Absorber Cooling water

inlet temp

Cooling water

outlet temp

Cooling water

inlet pressure

MPa

Cooling water

flowrate

m3/h

Condenser Cooling water

outlet temp

Cooling water

outlet pressure

MPa

Note

2. Operation management

Management of solution In the initial stage of the operation of the chiller, the content of lithium chromate (or

lithium molybdate) in the solution would decrease due to the generation of the protective film.

And if there is rust or air in the chiller, even an extremely little amount, will lead to chemical

reactions, which in turn will raise the pH value of the solution and even accelerate corrosion of

the chiller. Therefore, the solution should be sampled to check the content of lithium chromate

(or lithium molybdate), iron ion, copper ion, chlorine ion, etc. as well as the pH value of the

solution after the chiller has run for a period of time.

If the content of lithium chromate (or lithium molybdate) drops below 0.1% (or 0.012%),

add some more in time. And the pH value should be kept between 9.0 and 10.5. If its too high,

adjust it with hydro bromic acid (HBr); if its too low, adjust it with lithium hydroxide ( LiOH).

Management of refrigerant water If the specific weight of the refrigerant water is greater than 1.0 during the running of the

chiler, which means the refrigerant water contains lithium bromide. This is also called

Polluted refrigerant water, which will lower the cooling capacity. The refrigerant water is

usually regarded normal when its specific weight is less than 1.02, otherwise it must be

regenerated and the cause of the pollution be analyzed to prevent its recurrence.


25

Regeneration of the refrigerant water is as follows:

1) Start the refrigerant pump and open the regeneration valve F3, pumping the

refrigerant water in the evaporator into the absorber via a by-pass.

2) Close F3 and stop the refrigerant pump; 3) When the solution has been concentrated and the refrigerant water has condensed on

the evaporator to a certain amount, restart the refrigerant pump.

Replenishment of octanol

Octanol is insoluble in the solution. After the chiller has run for some time, part of octanol

will float on the surface of the refrigerant water and the solution. And since octanol is a volatile

substance, the running of the vacuum pump will bring some octanol out of the chiller, thus

reducing its circulating amount and affecting the chillers performance. Therefore, octanol

should be replenished as required.

The method for charging octanol is similar to that for the solution. Remember to start the

vacuum pump after the charging to remove the air that might leak into the chiller during the

charging.

Management of water quality

The performance and life span of the chiller depend largely upon the quality of the cooling

water. Water of poor quality is easy to scale on the wall of heat transfer tubes, reducing the

cooling capacity.

The water used in the LiBr absorption chiller should comply with the requirements shown

in Table 8-1. If the water is too hard, soften it before using it.


26

Table 8-1 Water quality standard

Item Unit

Quality of cooling water Quality

standard for

recharged

water

Standard

value

Tendency

Corrosion Scaling

PH25 6.58.0 + + 6.58.0

Conductivity(25 microhm/cm

27

Part 9 Troubleshooting 1. Crystallization

During cooling cycle, when crystallization occurs in the concentrated solution in LTHE or

pipes, the temperature of the automatic de-crystallizing tube will rise and an alarm will be

given, while the temperature of the concentrated solution pipe leading to the absorber fall

dramatically.

Remedy Stop the cooling water pump and chilled water pump, and close the steam cut-off

valve to 40%. Now the high-temperature concentrated solution coming out of LTG

flows directly into the absorber via the de-crystallizing tube and heats the diluted

solution in the absorber. The heated diluted solution then enters LTHE, heats the

concentrated solution there and melts the crystals.

For crystals in pipes, melt them by heating them directly with steam, high-temperature water or flames.

2. Refrigerant water pollution In cooling operation, the phenomenon of LiBr solution mixing into the refrigerant water is

referred to as refrigerant water pollution.

Severe pollution will result in a great drop in chiller performance or even operation failure.

The refrigerant water should be regenerated if its density exceeds 1.02.

Regenerating method

With the refrigerant pump running, open the refrigerant water by-pass valve, diverting the polluted refrigerant water in the evaporator to the absorber.

Causes of refrigerant water pollution

Circulating solution amount is too large and the liquid level in the generator is too high.

At the beginning of the chiller operation, the pressure of the solution vapor rises too

fast, causing the solution in the generator to boil too violently and enter the

condenser.

The cooling water temperature is too low.


28

3. Common faults and remedies (see Table 9-1)

Table 9-1

S/N Faults Possible causes Remedies

1 Chiller cant be started

aNo power is connected to the control cabinet

bFuse in the control cabinet blows

aCheck the main power supply and control switch

bCheck the grounding wiring or short circuits, and replace the fuse

2

Cooling capacity lower than the set point

a Poor sealing causes air leakage into the chiller

b Refrigerant water is polluted

c Circulating amount of the diluted solution is too small

d Vacuum pump is poor in pumping performance

e Spraying device is blocked f Scaling or clogging of heat

transfer tubes g Cooling water temp is too

high h Cooling water flow rate is

too small i Vapor pressure is too low

a Start the vacuum pump to pump air out and eliminate the leakage

b Examine the density of refrigerant water. If it is over 1.02, regenerate it

c Increase the frequency of the inverter

d Test the vacuum pumps performance and repair the fault

e Clean or replace spraying device f Eliminate scales and impurities on

the inside wall of heat transfer tubes g Regulate the cooling tower and

check the cooling water system h Raise the cooling water flow rate i Increase the vapor pressure

3 Chilled water outlet temp is too high

a External load is greater than the chillers cooling capacity

b Cooling water flow rate is too small or its temp is too high

c Set point of the chilled water is too high

d The amount of octanol decreases

e There are non-condensable gases in the chiller

a Decrease external load b Increase the cooling water flow rate

or decrease its temp c Reset the set point of the chilled

water temp d Add octanol e Start the vacuum pump to pump out

non-condensable gases

4 Refrigerant water is polluted

a Circulating amount of the solution sent to HTG is too large and liquid level in HTG is too high

b Cooling water temp is too low and cooling water amount is too large

a Regulate the frequency of the inverter

b Decrease the amount of the cooling water


29

5 Crystallization in LTHE

a Cooling water temp is too low

b Circulating amount of the solution sent to HTG is too small

a Increase the cooling water temp and decrease its flow rate moderately

b Increase the circulating amount of the solution which is sent to HTG

6 Crystallization of solution after shutdown

a Dilution time is too short b Chillers ambient temp is

too low

a Increase the dilution time, guaranteeing full mixture of the solution

b Add refrigerant water to dilute the solution, preventing it from crystalizing

7 Cavitation erosion in solution pump

a Insufficient solution amount

b Crystallization of solution

a Add solution b Melt crystals

8 Purge system runs abnormally

Incorrect operation of purge valves

Check if the valves are correctly opened or closed, or tightened.

9 Vacuum degree drops Leakage

Check to see if valves or instruments connected directly to atmosphere are loose, or valve diaphragms become aged

4. Treatment for action of safety devices

During operating, the chiller will stop automatically and give an alarm if any failure

occurs and the safety protection level has been reached. Remedies for the action of safety

devices are listed in Table 9-2 below.


30

Table 9-2 Remedies for action of safety devices

S/N Location of action Remedies

1 Cooling/chilled water flow switch operates

a Check to see if the operation of water pumps is normal. b Check to see if pressure is normal and if air enters water system.

Discharge air if air enters water system. c Check to see if valves are open and open them wider. d Check to see if filters are clogged.

2 Cooling/refrigerant water temp over load alarm

a Check to see if external load is lower than the cooling capacity adjusting range.

b Check to see if cooling water temperature is too low.

3 HTG pressure switch operates

a Check the airtightness of the chiller, seeing if the purge system operates normally, and if there is any leakage.

b Check to see if vapor pressure is too high. c Check to see if the cooling water flow rate is too small. d Check to see if scaling occurs in the absorber/condenser heat

transfer tubes.

4 HTG low liquid level alarm

a Check to see if the level control electrode is sensitive. b Check to see if the solution pump runs normally. c Check to see if the liquid level is normal.


31

Part 10 Maintenance 1. Maintenance during short-term shutdown

During short-term shutdown(less than two weeks), the chiller should be maintained as

follows:

Keep a high vacuum degree in the chiller. If air enters the chiller, pump it out timely.

Track the temperature change to prevent crystallization.

During dilution before shutdown, transfer all refrigerant water in the evaporator to the absorber via the by-pass valve, ensuring full dilution of the solution.

When doing repairs during shutdown period, such as replacing the canned pump or

valves, avoid exposing the inside of the chiller to the atmosphere for a long time. So

conduct the repair quickly, otherwise the chiller may be eroded.

2. Maintenance during long-term shutdown Great attention should be paid to the long-term shutdown maintenance in order to ensure

the chillers high performance and long life. The maintenance work includes:

Preventing air leaking into the chiller and causing corrosion Vacuum method: Start the vacuum pump regularly (every 15-30 days) to pump out

air which has leaked into the chiller.

Nitrogen method: Charge high-purity nitrogen gas (99.999%) into the chiller until the pressure reaches 0.02MPa. Before charging, purge the valve and rubber

tube with the nitrogen gas to prevent air entering the chiller.

For both methods, the diaphragm valves should be sealed lest it should be opened by accident!

Preventing crystallization

During the dilution operation prior to shutdown, transfer all refrigerant water in the evaporator to the absorber via the by-pass valve, allowing solution coming

from different parts of the chiller to mix fully and preventing crystallization.

Cleaning heat transfer tubes and water system Open the water chambers of the absorber, condenser and evaporator, check heat

transfer tubes, and remove residues in water chambers and heat transfer tubes.

If there is scale in the tubes, chemical methods may be used to remove it. The 81-A acidic cleaning agent produced by Shanghai No.2 Reagent Factory is

recommended. The cleaning process is as follows: make the cleaning agent into a


32

5-10% solution, heat it to 50-60 and circulate it through the transfer tubes. It

normally takes about 18 hours to eliminate 1mm-thick scale. After the cleaning,

drain the cleaning agent, charge 0.5-1% solution of trisodium phosphate (Na3PO4)

or sodium carbonate (Na2CO3) into the tubes and circulate it to neutralize the

acidic solution left in the tubes.

Preventing oxygen corrosion and icing

After cleaning up heat transfer tubes and water system,

If icing is impossible, the water system should be fully charged with water to

prevent oxygen corrosion in water chambers of the absorber, condenser and

evaporator.

If icing is possible, drain heat transfer tubes and water system and dry them to

avoid frozen tubes and reduces oxygen corrosion.

Check and replace failed parts Such as the graphite bearing of the canned pump, valve sealing rings,

diaphragms of diaphragm valves, auto-control components and spring for the

rotary vanes of the vacuum pump.

While replacing the parts of the vacuum system, avoid exposing the inside of the

chiller to the atmosphere for a long time.

All electrical equipment and instruments should be protected against moisture.

3. Treatment of LiBr solution

If LiBr solution becomes turbid and turns dark red, black or green, it must be treated.

There are two methods to treat the solution

Deposition method: put the LiBr solution in a large container, after a certain period

of time, the deposits will settle on the bottom of the container and the solution will

become clear again. Extract the upper clean solution and reuse it.

Filtering method: use a strainer made of propylene, with its meshes being 3mm in

diameter, to filter the solution. While filtering solution containing deposits, it is

recommended to filter it after it has been deposited for 1 or 2 days. Do not use a

strainer made of cotton fiber.

Then measure the content of lithium chromate (or lithium molybdate) and pH value, and

adjust them to the specified values.

4Regular check The chiller should be checked periodically, during both operation period and shutdown


33

period, to maintain its good performance and safety running. The check items are listed in the

following table.

Table 10-1 Regular check items

Items Check points Check cycle

daily weekly monthly yearly

Vacuum pump a) Pollution and emulsification of oil b) Performance of vacuum pump c) Insulation of motor

Solution pump & refrigerant

pump

a) Operating status of the chiller. Check to see If there is any unusual noise

b) If power supply to motor exceeds the normal value

c) Insulation of motor d) Dismantlement and check of vanes; cleaning

of return pipes

Every about 5 years

e) Replacement of graphite bearing Every 5 years

LiBr solution

a) Concentration b) Cleanness degree c) pH value and lithium chromate(or lithium

molybdate) concentration

Refrigerant water

Check its pollution condition and decide whether to regenerate it

Heat transfer tubes

a) Corrosion of inner wall b) Scaling on inner wall

Sealing of chiller

a) Change of temperature difference between diluted solution and cooling water; change of cooling effect

b) Record of pressure changes during shutdown period

Diaphragm valves and

solution adjusting valves

a) Sealing condition b) Replacement of diaphragms of valves 1 and 2 Every 3

years c) Replacement of diaphragms of other

diaphragm valves Every 5

years

d) Replacement of the O-ring of the changeover valve

Every 5 years

Pressure gauge and control

cabinet

a) Calibration of indication b) Insulation of electrical devices c) Reliability of switches for electrical devices


34

Operation Rules

(Double-effect steam-fired LiBr absorption chiller)

1. Machine room management rule (1) The operators must observe this rule to ensure safe running of the chiller.

(2) There should be strict management regulation and shift regulation for the machine room.

(3) There should be personnel on duty in the machine room during running of the chiller.

(4) No one other than qualified persons is allowed to operate the chiller alone.

(5) No one other than the operators is allowed to enter the machine room without permission.

(6) No one other than machine room staff is allowed to open or close any valve or other

components of the chiller, otherwise accident may occur.

(7) The machine room should have excellent ventilation and the relative humidity in it should

be controlled below 75%.

(8) The power supply in the machine room should be normal with stable voltage.

(9) The machine room should have sufficient high-purity (99.999%) nitrogen gas and

common tools, materials and spare parts which are necessary for the maintenance of the

chiller and system.

2. Safe operation rule (1) It is prohibited to change safety protection parameters. For example, the set point of the

HTG temperature (cooling) is 160.

(2) It is prohibited to adjust safety devices. For example, the set point of the pressure

controller is 0.02MPa.

(3) It is prohibited to start the chiller if there is any abnormality with safety protection

functions.

(4) It is prohibited to start the chiller if there is any abnormality with the target flow regulator

for chilled water.

(5) It is prohibited to start the chiller if there is any leakage.

(6) It is prohibited to start the cooling water pump first and then start the chilled water pump.

(7) It is prohibited to stop the chilled water pump first and then stop the cooling water pump.

When the cooling water temperature is low (25), the chilled water pump must be

stopped two to five minutes after the cooling water pump has been stopped.

(8) It is prohibited to start the chiller if the chiller is obviously vibrated by the piping system.


35

3. Chiller operation rule Check the following items each time before starting the chiller

(1) Confirm that the valves at the chilled/cooling water inlet/outlet are open.

(2) Confirm that the safety protection parameters are properly set and select Auto

operation mode on the touch screen.

(3) Safety devices should work normally, particularly when the flow rate of chilled or

cooling water is lower than the specified value, an alarm can be given, the working

steam be cut off, and the chiller be stopped automatically.

Start sequence

(1) Start the chilled water pump first, observe its inlet-outlet pressure difference, and

confirm that the water flow rate meets the operation requirement.

(2) Start the cooling water pump.

(3) Open the by-pass valve for the vapor condensate, and close it after the condensate

water in the pipe has been drain. Then open the vapor cut-off valve.

(4) Press the Auto key.

(5) Start the cooling tower fan when the cooling water inlet temperature reaches 30 (if

the system adopts interlock control, the cooling tower fan will start automatically).

Stop sequence

(1) Press the Stop key and manually close the vapor cut-off valve.

(2) Switch off the power after the automatic dilution process ends.

(3) Stop the cooling tower fan and cooling water pump.

(4) Finally, stop the chilled water pump.

Operation monitoring

(1) Make detailed operation records which are used for the analysis of the chiller

operation condition.

(2) Monitor the liquid level in HTG and the temperature and pressure of the solution in

HTG. The liquid level mustnt be too low, and the temperature and pressure mustnt

be too high, otherwise the heat transfer tubes will be damaged.

(3) Monitor the running of the canned pump. If its shell temperature exceeds 80, stop it

immediately and troubleshoot the problem.

(4) Check to see if the working steam pressure is within the specified range.

(4) Shut off the working steam immediately in any of the following circumstances:

Loss of chilled water flow or failure in the canned pump

Serious air leakage Liquid level rises unexpectedly or disappears


36

Accidental power failure

4. Emergency treatment rule

When any significant fault occurs during the running of the chiller, the machine room staff

must take corresponding measures as soon as possible.

Copper tubes are frozen or damaged

Symptom: Liquid level at various locations rises too greatly and the cooling effect

disappears.

Remedy:

1) Stop the chilled water pump and close the valves at the chilled water inlet and outlet at once.

2) Turn off the main switch in the control cabinet and stop the cooling water pump.

3) Drain the water from the water chamber. 4) Charge nitrogen gas into the chiller until the pressure reaches 0.02MPa.

Discharge the solution into the solution tank for regeneration.

Sudden power-off during operation 1) Close the vapor cut-off valve at once.

2) Resume power supply and start the chiller as soon as possible lest the

concentrated solution should crystallize.

5. Maintenance rule

Maintenance should be performed strictly in accordance with the Operation Instruction.

Maintenance should be performed by or under the direction of qualified personnel.


37

Appendix 1Saturated water vapor temperature & pressure table

Temperature Pressure Temperature Pressure

kgf/cm2 mmHg kgf/cm2 mmHg

1 0.006697 4.93 66 0.2666 196.2

2 0.007194 5.29 68 0.2912 214.3

4 0.008289 6.10 70 0.3178 233.8

6 0.009530 7.01 72 0.3463 254.7

8 0.01932 8.04 74 0.3769 277.3

10 0.0125 9.2 76 0.4098 301.5

12 0.014292 10.5 78 0.4451 327.4

14 0.01629 12 80 0.4829 355.3

16 0.018529 13.6 82 0.5234 385

18 0.021034 15.5 84 0.5667 416.9

20 0.02383 17.5 86 0.6129 450.9

22 0.026948 19.8 88 0.6623 487.2

24 0.030415 22.4 90 0.7149 525.9

26 0.034266 25.2 92 0.7425 546.2

28 0.038536 28.3 94 0.8306 611

30 0.043261 31.8 96 0.8941 657.7

32 0.04848 35.7 98 0.9616 707.3

34 0.05424 39.9 100 1.033 760

36 0.06058 44.6 102 1.087 799

38 0.06756 49.7 104 1.166 858.7

40 0.07522 55.3 106 1.250 919.6

42 0.08362 61.5 108 1.339 985.1

44 0.09281 68.3 110 1.432 1053

46 0.1028 75.7 112 1.531 1126

48 0.1138 83.7 114 1.636 1026

50 0.1258 92.5 116 1.746 1284

52 0.1388 102.1 118 1.862 1370

54 0.1530 112.5 120 1.98 1456

56 0.1683 123.9 125 2.366 1740

58 0.1850 136.1 130 2.754 2026

60 0.2031 149.4 135 3.192 2348

62 0.2227 163.8 140 3.684 2710

64 0.2438 179.4 145 4.236 3116


38

Appendix 2System diagram

Chilled water system Cooling water system Steam system

LoadExpansion water tank

Cooling tower

Pressure reducing valve

Working steam in

Condensate out

Check valve Steam trap Electric valveCut-off valve

Filter Flexible connectorThermo-meter

Pressure gauge


39

Appendix 3Solubility curve of LiBr solution

t

100.0

75.0

50.0

25.0

0.0

-25.0

-50.050.0 55.0 60.0 65.0 70.0 50.0

LiBr %

Crystallization temperature curve of LiBr solution

(smoothed values) Horizontal axis: LiBr %

Vertical axis: Crystallization temperature


40

Appendix 4Users water system linkage diagram

3

: 1AC250V,5A

()

Q131 Q132 Q141 Q142 Q152Q151

Control cabinet for Hope Deepblue steam-fired absorption chiller

Chilled water pump run command

Cooling water pump run command

Cooling tower fan run command

Note: 1. The capacity of the output relays for the linkage terminals of above

water pumps is AC 250V, 5A (resistance load). 2. Q131, Q132, Q141, Q142, Q151 and Q152 are code numbers for wires

in the control cabinet. Please pay attention not to misconnect them. 3. While running the unit, make sure the chilled water pump and cooling

water pump are in linkage control.

Non-voltage output


41

Appendix 5Control cabinet I/O terminals

T3A

PE

V4

04

PEL1

NNL2

0102

03

V2U2

L3W2

U4

0506

0807

09

15

W4NN

1211

1013

14

A07

A03

NN

1816

1719

20

T0A

L3NN

PEL1

L2U2

V2U4

W2V4

A131

VPVP

E211

E22

A142

A141

A132

A152

A151

W4NN

NNA07

A03

PE

T0BT0CT1AT1B

T2B

T2A

T1C

T2C

A132

VPE21

VPA131

E22

A142

A151

A141

T0A

A152

T1C

T1A

T0C

T0B

T1B

T2B

T2A

T3A

T2C

YW4

32

VP

26

W5U5

V5A172THR

2221

2325

24

E241

YW1

YW3

YW2

2927

2830

31

E07

YW5

VP

33

YW5

VP

V5U5

W5THR

A172

YW2

E241

YW1

YW3YW4

T3C

T3B

T5B

T5A

T5C

E07

VP

T3C

T3B

T5B

T5A

T5C

4041

4342

4445

4746

4853

4951

5052

5554

6157

5659

5860

6362

NN

3839

NNA11

NNA12

NNA11

A12

NN

T4A

T4BT4C

T4A

T4C

T4B

E21

JXP

JXP

3435

3637

HTG

tem

p C

oolin

g w

ater

in

let t

emp

Evap

orat

ion

tem

p C

hille

d w

ater

in

let t

emp

Chi

lled

wat

er

outle

t tem

p So

leno

id

valv

e se

t Va

cuum

pu

mp

Ref

riger

ant

pum

p th

erm

al

prot

ectio

n

Ref

riger

ant

pum

p

Pow

er su

pply

to

cont

rol c

abin

et

Exte

rnal

ac

oust

oopt

ic

war

ning

Coo

ling

tow

er fa

n C

oolin

g w

ater

pu

mp

Chi

lled

wat

er

pum

p

Liqu

id le

vel

elec

trode

term

inal

So

lutio

n pu

mp

term

inal

H

TG

high

pr

essu

re

faul

t

Coo

ling

wat

er

cut-o

ff

Chi

lled

wat

er

cut-o

ff

Dec

ryst

alliz

ing

tube

tem

p


42

Appendix 6Electrical principle diagram

Electrical Principle Diagram


steam powered absorption chiller installation and operation manual tt

Documents

system diagram

control system

clean fresh water

special orders cooling

installation of system

working steam

saturated vapor

cooling cycle