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This document provides information about vapour absorption cooling systems and their components. It discusses: 1. The basics of lithium bromide and water used in absorption systems. 2. Duhring diagrams which show the relationship between vapour pressure, temperature, and lithium bromide concentration. 3. Pressure profiles for single and double effect machines. It also summarizes materials used for tubes, plates, and valves. Burners, cycle diagrams, and coefficient of performance are briefly covered.

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1 HOW DOES THE VAPOUR ABSORPTION WORK
2
3 Basics • LiBr – Hygroscopic Nature – Properties • Water – Properties
4
5
6
8 WHAT IS A DUHRING DIAGRAM ? • A Duhring Diagram shows the relationship between the vapour pressure and LiBr solution with respect to pressure,temperature and concentration of LiBr,at equilibrium
9
10 c C d a b j i 58 6 4.5 38 95 TEMPERATURE ( DEG C) Absorber (j-b) Absorber (a-b) Evaporator a Condenser (d-i) REFRIGERANT CYCLE ABSORBENT CYCLE DUHRING DIAGRAM FOR S.E M/C c Gen (c -d) 68 40 55
11 PRESSURE PROFILES • DOUBLE EFFECT LOWER SHELL - 6 mm Hg HIGH TEMPERATURE GENERATOR - 707 mm Hg LOW TEMPERATURE GENERATOR / CONDENSER - 58 mm Hg • SINGLE EFFECT LOWER SHELL - 6 mm Hg UPPER SHELL - 70 mm Hg
12 PRESSURE PROFILES • DOUBLE EFFECT LOWER SHELL - 6 mm Hg HIGH TEMPERATURE GENERATOR - 707 mm Hg LOW TEMPERATURE GENERATOR / CONDENSER - 70 mm Hg • SINGLE EFFECT LOWER SHELL - 6 mm Hg UPPER SHELL - 58 mm Hg
13 HOW DOES THE VAPOUR ABSORPTION CREATE AND MAINTAIN VACUUM
14
15 COEFFICIENT OF PERFORMANCE • Coefficient of Performance(COP) is the measure of efficiency in a heat pump or refrigerating machine. • COP = Refrigeration effect/Heat input • COP for different types of Heat Pumps are as follows :- Double effect type = 1.2 Single effect type = 0.65 - 0.7
16 Materials used in VAM/cs • Tubes – Evaporator, Absorber, Condensor – High Temperature Generator Steam and Heat Reclaimer (DE only) – Low Temperature Generator (only DE) – Heat Exchanger High (only DE) – Heat Exchanger Low
17 Materials used in VAm/cs • Plates – Shells, Tube sheets and boxes • Valves – Angle, Service, Check, Dampers • Trays and Eliminators
18 Tubes in Evaporator , Absorber, Condensor - • Standard - DLP Grade Copper seamless • 16 or 19 OD, 0.6 mm thk • Standards - JIS H 3300 - C1201T 1/2H or [ASTM B 75] • Deoxidised Low Phosphorous • Cu - 99.90 min • P - 0.004 to 0.010 • Non standard - CuNi 90/10, CuNi 70/30, SS 316L, Titanium
19 Tubes in High Temperature Generator and Heat Reclaimer • Ferritic Stainless Steel - SS 430 Ti, SA 268 - Grade TP 430 Ti • C- 0.1, Mn 1.00, P-0.040, S-0.030, Si- 1.00, Ni-0.75 max,Cr 16.00-19.50, Ti- 5xC min, 0.75 max • 19 OD, 1mm thk -Welded • Ti grade for improved welding yield • Coefficient of Thermal Expansion close to that of CS - No stresses developed at operating temperature
20 Tubes in Low Temperature Generator (only DE) • DLP Grade Copper seamless • 19.05 OD and 1.42 thk
21 Tubes used in Heat Exchanger High • Spiral tubes of CuNi 90/10 material • OD 9.5mm and thickness 0.5mm • Spiralling done to increase turbulence thereby increasing heat transfer
22 Tubes used in Heat Exchanger Low • Spiral tubes of DLP grade Copper • OD 9.5mm and thickness 0.5mm • Spiralling done to increase turbulence thereby increasing heat transfer
23 Steel plates for shells, tube sheets and boxes • IS 2062 Gr B • Option : SA 515/516 Grade 60 or 70 • Carbon Steel - C - 0.2 % • Sulphur and Phosphorous controlled • Manganese added for stabilization
24 Valves - Angle, Service, Check, Dampers • SS 304 and carbon steel • Gaskets - Viton, Valvelon
25 Trays and Eliminators • SS 430 - 0.3 and 0.8 mm thk
26 CYCLE DIAGRAMS
27 DOWN VALVE REFRIGERANT PUMP ABSORBENT PUMP REFR BLOW PUMP PURGE GENERATOR CONDENSER LOW TEMP HEAT EXCHANGER OVER FLOW PIPE STEAM CONTROL VALVE ProChill Series Flow Cycle Single Effect Steam Driven
28 SUPPLEMENTARY FIRED EXHAUST GAS DRIVEN ABSORPTION MACHINE FIG. N0. 8
29 STEAM DRIVEN SINGLE DOUBLE EFFECT ABSORPTION MACHINE FIG. NO. 9
30 SUPPLIMENTARY FIRED EXHAUST GAS DRIVEN SINGLE DOUBLE EFFECT ABSORPTION MACHINE FIG. NO. 10
31
32
33 TWIN HOT WATER MACHINE TWIN HOT WATER MACHINE 90 33 3333 33 33 33 33 90 76 75 34 35 15 8 Low conc ,High Chw temp. zone 11 39 High conc, Low Chw temp.zone
34 SOLENOID VALVE REFRIGERANT PUMP ABSORBENT PUMP PUMP PURGE LTG CONDENSER LOW TEMP HEAT EXCHANGER OVER FLOW PIPE HEAT RECLAIMER TEMPERATURE GENERATOR HIGH EXCHANGER HIGH TEMP HEAT STEAM CONTROL VALVE Dou ble Effect Steam Fir ed Cycle Diagr am REF BLOWDOWN VALVE
35 BURNERS
36 BURNERS The burner operates by sucking in the fuel and combustion supporter air, mixes them thoroughly together and safely ignites them inside the heat generator furnace. BURNER PARTS 1) COMBUSTON HEAD: Fuel + Air Creates Flame 2] AIR SUPPLY : Fan + Pipes ( for taking air to combustion head) 3] FUEL SUPPLY : Fuel flow & Safety of combustion system 4] ELECTRICAL : Control Components ( req. for flame & motor)
37 Gaseous fuels and Burners Gas burners can be classified as follows: • Natural draught burners • Induced draught burners • Forced draught burners Natural Draught Burners - burner uses fuel gas supply pressure to pull air through Venturi sys. - burners can be extremely sensitive to combn chamber. - primary air can reach up to 50%.
38 Induced Draught Burners - burners are used, with a fan fitted up-stream or down- stream from combustion chamber. - primary air can reach up to 100% Forced Draught Burners - air flow rate is guaranteed by elevated head pressure fans. - draught operating condition more or less independent of burner operation. - possible to operate with low excess air & increases combustion efficiency.
39 Liquid fuels and Burners Liquid burners can be classified as: • Mechanical atomization • Pneumatic atomization • Centrifugal atomization Mechanical atomization - atomization is a result of mechanical pressure exerted on the liquid , when it reaches the atomizing nozzle. - fuel oil is split into great deal of extremely small droplets., size of drops depends upon exerted pressure.
40 Pneumatic atomization - atomization is a result of Pneumatic pressure exerted on the liquid , when it reaches the atomizing nozzle. - this system guarantees excellent fuel atomization levels for dense fuel oils - complicated structure & higher installation cost. Centrifugal atomization - drops of fuel are formed by applying a centrifugal force to liquid fuels. - liquid fuel must have sufficiently low viscosity.
41 • The viscosity required for obtaining sufficient fuel oil atomization varies according to the type of burner. • The nozzle required oil viscosity between 6 - 40 Cts at 50 O C in relation to the type of fuel. • This viscosity value determines the pre-heating temp value e.g. supposing we use a fuel oil with viscosity of 150 Cts at 50 O C , to obtain the value of 17 Cts needed by the nozzle to obtain the right atomization, the fuel must be preheated to a temperature between 90 to 100 O C.
42 Force Draught Burners (Classification based on construction ) Mono-block Dual Block Fan + Pump Fan + Pump are integral part are not integral of burner forming part of burner & a single stage body. Forms a separate part of burner
43 Force Draught Burners (Classify depends upon output delivery ) • Single stage burners : Operates with single stage delivery, fuel delivery is invariable and burner con be switched on or off (ON-OFF). T Start up Start up Stop Stop
44 Force Draught Burners (Classify depends upon output delivery ) • Multi- stage burners : Usually two- stage or three-stage , are set for running at one or more reduced out put speeds or at maximum out put (OFF-LOW- HIGH or OFF-LOW-MID-HIGH) • switch over from one stage to another can be automatic or manual T Start up 1st stage Start up 2st stage Stop 2st stage Stop 2st stage Start up 2st stage Stop 2st stage P
45 Force Draught Burners (Classify depends upon output delivery ) • Modulating burners : Delivery output is automatically varied continuously between a minimum and maximum , for optimum delivery of the thermal output in relation to system requirements. T Start up Stop P
46 BURNERS • ACD - VAMS USE EITHER OF THE FOLLOWING BURNERS • A) Nu-Way - For L Series • B) Riello- For M series • C) Bentone For earlier M series Machines • Classification of Burners : • A) Out put Delivery • Single Stage Burners
48 Classification • Monoblock Burners : Pump and fan are integral part forming a single body. • Dual Block : Fan, pump and othe parts are separate from main Body • Basic Parts: • Burner Body Housing : Diffuser Plate, Ignition electrodes , flame sensor, Combustion Head , with Nozzle assembly, Cone etc.
49 • Other parts : Pump, Blower, Pressure gages etc are mounted depending on the constructions. • Control Panel: Includes Sequence Controllers,Ignition transformer relays etc. • Fuels : HSD/Kerosene/GAS • For Smaller range of burners Pump pressure can vary from 11 to 15 kg/cm^2g.
50 • Typical Values of combustion Parameters(OIL) • O2 3.0% • Co2 13% • Co Below 50 ppm • Typical Values of combustion parameters (GAS)
51 • Oxygen O2 3.0 % • Carbon dioxide : 10 % • Carbon Monoxide : Below 50 % • Nozzles: Monarch or Danfoss • Nozzles are rated at 100 Psi • Selection Criteria for burners • a) Thermal Capacity at the heat generator furnace
52 • B) Back pressure in combustion chamber • C)Type of generator • D) Fuel • E)Burner Operation Mode
53 Gas burners • PRV • Multibloc/Air to Gas ratio Controller • Gas pressure switch • Solenoid Valves • Ignition electrodes
54 BURNER GAS VALVE TRAIN 1. Gas valve (Multibloc) 1.1Gas filter 1.2 Pressure switch, min. 1.3 Main gas valve 1.4 Pressure regulator 1.5 Gas valve, 2-stage 2. Valve leak tester (burner capacity > 1200 kW) 1. Ball valve, blow-off 2. Gas pressure switch, min. 3. Valve leak tester 4. Gas valve (DMV-D) 5. Ignition gas valve 6. Gas butterfly valve 7. Gas pressure switch, max. 8. Differential air pressure switch 2-STAGE MODULATING
55 COMPONENTS OF BURNER AND ITS FUNCTION • Gas Train – Pressure proving system - for checking leak tightness of valves – Main safety valve - Quick closure of gas supply in case of trip. – SKP 70 valve - Combined valve & Gas/air ratio regulator – Pilot solenoid valve & Gas governor - For establishing pilot flame – High & Low gas pressure switch - for checking minimum & maximum gas pressure conditions • Air system (Burner motor with fan): – Air damper with modulating control (cam) for controlling air flow thereby controlling gas flow. – Air pressure switch for cutting of burner in case of low air pressure • Gas flame tube & Air diffuser for creating proper mixture of gas & air for good combustion • Electrode & Transformer for initial ignition • Sequence controller for controlling time sequence of operations.
56 PRESSURE PROVING SYSTEM
57 Components of Gas Train
58 Air Damper control & Combustion control
59 Fault Finding instructions in Brief • BURNER MOTOR FAILS TO START – Check Burner electrical control – Check start command from Machine panel • BURNER MOTOR ONLY RUNS CONTINUOUSLY(NO FIRING) OR BURNER DOES NOT MODULATE – Check air damper control wiring and functioning • BURNER GOES TO LOCKOUT BEFORE FIRING – check functioning of Air pressure switch, Electrode and tranformer, Gas pressure, all Valve operations, Gas to air pressure ratio etc. • BURNER FIRES BUT GOES TO LOCK OUT WHEN IT MODULATES FROM LOW TO HIGH FLAME – check gas to air ratio ,Air damper setting high,main gas valve not operating etc.
60 CRYSTALISATION
61 CRYSTALLISATION Crystallisation of LiBr occurs when LiBr percentage in solution is more than that can be dissolved in the solution at specific temperature.
62 Effects of crystallisation • Less or no capacity • Indirect fired machine if generator is crystalised then tube failure due to over heating. Choking of pipe lines and heat exchangers leading to blocked flow
63 When crystalisation occurs? Low solubility Low solution temperature High concentration Both together
64 100 % 0 % 0 10 Distance from cryst. line Valve Opening Concentr ation
65 When crystallisation occurs? – Cooling water temperature low – Dilute solution temperature low – LTHE spray solution temperature low – Low solubility – Crystallisation •Low solution temperature
66 When crystallization occurs? • High concentration • Excess heat input due to – High steam pressure – Faulty control valve / control mechanism – Steam control valve bypass open – Contamination of LiBr in evaporator – Air ingrace – Low solution flow from pump – some other fault in machine due to which capacity of machine is low. – Excess load • Also combination of above will cause severe crystallization.
67 DOWN VALVE REFRIGERANT PUMP ABSORBENT PUMP REFR BLOW PUMP PURGE GENERATOR CONDENSER LOW TEMP HEAT EXCHANGER OVER FLOW PIPE STEAM CONTROL VALVE ProChill Series Flow Cycle Single Effect Steam Driven
69 Start of crystallization / minor crystallization • Pump delivers LiBr to generator • Due to minor crystallization resistance on spray side of LTHE increase • Return flow to absorber lowers • Absorber out flow > return flow(Absorber in) • Absorber level starts dropping • Less return flow means lower absorption of water vapour from evaporator • Evaporator level rises • Over flow pipe becomes hot
70 Starting symptoms of crystallization • Low capacity inspite of good generator temperature • Low absorber level • High evaporator level • Overflow pipe hot
71 Major crystallization • Absorber becomes empty • solution flow to generator reduces drastically • Due to low capacity high chilled water temperature • Control valve opens - full heat to generator • Low dilute flow to generator means no dilution force in generator inspite of full heat • Concentration shoots up very fast • Major crystallization
72 PREVENTIVE MEASURES • Low cooling water cut out • High generator temperature • Adequate refrigerant level (25% insight glass at full load) • Over flow pipe
73 Limitation of above preventive measures • Generator temperature senses temperature (indirectly concentration) • Crystallization depends on both concentration and temperature • At low cooling water temperature generator temperature is low even at high concentration. • Air ingrace / contamination results in rapid absorber depletion • Empty absorber stops diluting LiBr in generator • Thus crystallization cannot be avoided completely though in many cases it may avert.
74 Thermax’s New Crystallization free feature What is the solution?
75 CRYSTALLIZATION FREE MACHINE • Thermax technology - developed sophisticated computer program that calculates concentration of LiBr • PLC will check the distance of solution state point from crystallization line and operate steam control valve to avoid crystallization • Signal given to steam control valve by crystallization software will override chilled water temperature signal for valve opening • If level in absorber drops to 25% automatic blow down will dilute LiBr • If level in absorber becomes very low steam control valve will close.
76 CRYSTALLIZATION FREE MACHINE This way crystallization can never never occur.
77 B4K CHILLERS
78 B4K CYCLE DHE LTHE HR HTHE HTG TRAP CONDENSATE OUT 95°C 170°C 107°C 39°C 43°C 70°C 80°C 130°C FLOW 100% LTHE HTHE HTG CONDENSATE OUT 95°C 170°C 39°C 70°C 140°C 170°C 145°C HR DHE 39°C 74°C NEEDLE VALVE S OLD CYCLE FLOW 15% Ball Valve
79 SOLENOID VALVE REFRIGERANT PUMP ABSORBENT PUMP PUMP PURGE LTG CONDENSER LOW TEMP HEAT EXCHANGER OVER FLOW PIPE HEAT RECLAIMER TEMPERATURE GENERATOR HIGH EXCHANGER HIGH TEMP HEAT STEAM CONTROL VALVE Dou ble Effect Steam Fir ed Cycle Diagr am REF BLOWDOWN VALVE
80 PREVENTIVE MAINTENANCE • 750 HOURS OF OPERATION: – Check oil of Vacuum pump and change if required • 2000 HOURS OF OPERATION – Check working of safety devices – Check currents of all motors – Check combustion analysis – Note the readings in the performance report (all temperatures of various parts as mentioned in the report) – Collect sample of Lithium Bromide ( after running the machine in heater mode for 2 hours) for analysis of : • Inhibitor level • Alkalinity
81 PREVENTIVE MAINTENANCE • 8000 HOURS OF OPERATION – Overhaul vacuum pump – Charge Nitrogen and keep the machine under a slight positive pressure ( say 0.1 bar) – Check Evaporator / Absorber / Condenser tubes. Clean if required. Use only Nylon brushes for cleaning – Check Economiser tubes foar any carbon deposit – Replace diaphragm of purge valves . After the replacement and cleaning of tubes carry out nitrogen pressure test. – Replace UV cell of burner.
82 MAINTENANCE PROCEDURE • Make -up of Lithium Molybdate is required: – Vacuum leakage has occured – Repair of machine had been done after opening the machine to atmospheric pressure. – Loss of inhibitor in the form of non-condensables over a period of time and Analysis results shows inhibitor level is less. • Method of addition of Lithium Molybdate : – Should be charged only when the machine is running in cooling mode. Keep the vacuum pump in operation while charging. – Charging should be done through the service valve on refreigerant pump discharge. – Charging should be done very slowly (at the rate of 1 litre/minute). Just open the service valve slowly until it starts sucking. Do not open more than that. – Machine should be run in Cooling mode for atleast 2 hours after charging.
83 Procedure for storage with water in the circuit: Drain the dirty water from the header circuit. Do auxiliary washing of circuit from a location higher than machine. Fill at once with clean water, and operate the cooling / hot water pump and drain once again (30 min.~ 1 hour) after circulation washing. Fill with clean water once again. Maintain in the same condition.
84 Note: At the time of maintenance operation, the temperature of cooling / hot water system, with water inside the machine, increases above 90oC. Because hot water inside expands, the pressure inside increases. To relieve the pressure, crack open the air vent valve on the outlet of the machine.
85 Procedure for storage w/o water in the circuit: Drain the dirty water from the header circuit. Do auxiliary washing of circuit from a location higher than machine. Fill at once with clean water, and operate the cooling / hot water pump and drain once again [ 30 min~1 hour ] after circulation washing. Maintain in the same condition.
86 Function of Octyl alcohol: Surface active agent in the absorber, results in better wettability and heat transfer. (Marangonie Effect) Refrigerant vapour Tube Soln concentration becomes uniform at this point
87 AMMONIA ABSORTION FOR REFRIGERATION
88 Sequence • Thermax Introduction • History of Absorption Cycles • Compression and Absorption - Comparison • Explanation of Operating Cycle • Machine Illustration • Control System and Safety Features • Manufacturing and Component Features • Options - fuels etc • Application possibilities • Reference Installations • Feasibility Analysis • Summing up
89 Thermax Introduction • An Energy and Environment Company • 1500 people • 3 Core Business Areas – Cooling and Heating Products – Boilers, Heaters, Power, and Environmental Projects – Water and Waste water and Chemicals • India’s largest Absorption manufacturer International presence • 51,345 sq m of manufacturing space • Sales of 1200 Cr
90 History of Absorption Refrigeration • Cycle invented by Ferdinand Carre in 1846 • Ammonia as refrigerant and water as absorbent, at two pressure levels • Single pressure level cycle invented in 1922 by Munters and Platen • Considered useful only if waste was available • Invention of GAX cycle to improve efficiency • Resurgence of Ammonia Absorption as – Hydrocarbon fuels become expensive – Heat recovery applications become attractive – Solid fuel shift
91 Compression and Absorption - Comparison • Compressor is replaced by a combination of absorber, solution pump and generator Condenser Compressor High Pr Heat Evaporator Low Pr. Heat Condenser High Pr Heat Evaporator Low Pr. Heat Generator Absorber
92 BASIC OPERATING CYCLE Condenser Heat Exchanger Stripping Colm Rect Colm Partial Condenser Evaporator Cond Out In Out In Out In Out Expansion Valve Expansion Valve Cooling Water Cooling Water Cooling Water Brine Solution Pump Generator Steam In Subcooler In Out Bleed HE Absorber Animate
93 Machine Illustration Condenser and buffer tank Absorber Stripping Column Rectification column Evaporator Partial condenser Heat Exchanger Generator Solution Pump Sub-cooler
94 Utility Consumption • Steam Consumption – Evaporation Temp Steam Consumption – - 5 °C 9.25 kg/hr/TR – -15 °C 10.3 kg/hr/TR – -25 °C 11.75 kg/hr/TR • Cooling Water Requirement – Evaporation Temp CW Consumption – - 5 °C 1.55 m3/hr/TR – -15 °C 1.85 m3/hr/TR – -25 °C 1.96 m3/hr/TR
95 Minimum Steam Pressure Required – Evaporation Temp Steam Pressure – - 5 °C 2 kg/cm2g – -15 °C 3 kg/cm2g – -25 °C 5 kg/cm2g
96 Control system and Safety features • Fully automatic operation • Modulating Turndown from 100% to 10% • PLC control panel • LCD Operator Interface • 3 PID loops – Generator temperature control – Absorber solution flow control – Generator solution flow control • Pressure, temperature, flow, and level safeties • Relief valves on high and low side
97 Manufacturing and Component Features • Design of pressure vessels to ASME Sec VIII • ISO 9001 and ISO 14001 certified manufacturing • Heat exchangers sized for high efficiency • Compact design • Modularized design for quick installation • Stainless steel column internals for long life • Stainless steel solution distribution system • High Efficiency Grundfos solution pump • Standby pump for high availability
98 Options – fuels etc • Direct fired – Gas and Liquid fuel units • Genset Exhaust gas fired units • Optional partial condenser temperature control • Process integrated controls • Special tube metallurgy – SS, Ti etc possible • Two evaporation level systems • Integrated Ammonia and Brine systems
99 GAX Cycle Overview • Applicable above -5°C • Min Steam Pressure required : 9 kg/cm2g • Strong Aqua ammonia in heat exchange with weak aqua ammonia in the absorber • Weak aqua concentration : 10 % • Strong aqua concentration : 40 % • Steam consumption : 8 kg/hr/TR
100 Application possibilities • Brine systems – Reactor Cooling etc • Ammonia systems – Process chillers – Ice bank tanks – Ice block manufacture – Cold storages – Food processing – etc
101 Reference Installations - by Application / Industry • Process Integrated – HWB Heavy Water plant - Tuticorin – HWB Heavy Water plant - Baroda • Chemicals – - Shriram Fertilizers and Chemicals (DSCL) – - Sajjan India • Pharmaceutical – - Dishman Pharma • Dairy – - Milkfood Limited • Cold Storage – - JR Agro
102 Feasibility Analysis 200 TR - Steam fired AVAM (-25°C evaporation) Re. DESCRIPTION Unit Comp. AVAM 1 Capacity TR 200 200 2 Power consumption Unit kW 360.0 18.0 CW circuit kW 12.5 27.5 Cooling tower fan kW 4 10 3 Steam Consumption Unit kg/hr 0 2400 4 Total Operational Costs Power cost Rs. per kW Rs / kW 4.5 4.5 Steam cost per kg Rs / kg 0.45 0.45 Total Cost of Running - 8000 Hrs Rs lacs 135.5 106.4 5 Net Savings per annum Rs lacs 29.2
103 Summing Up • Replacement Cases – - Payback in 2 years • New Facility – - Payback in 6 months
104 BASIC OPERATING CYCLE Condenser Heat Exchanger Stripping Colm Rect Colm Partial Condenser Evaporator Cond Out In Out In Out In Out Expansion Valve Solution Control Valve Cooling Water Cooling Water Cooling Water Brine Solution Pump Generator Steam In In Out Absorber Bleed HE Subcooler Exit

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discription aboit vam and how it can works

  • 1. 1 HOW DOES THE VAPOUR ABSORPTION WORK
  • 2. 2
  • 3. 3 Basics • LiBr – Hygroscopic Nature – Properties • Water – Properties
  • 4. 4
  • 5. 5
  • 6. 6
  • 7. 8 WHAT IS A DUHRING DIAGRAM ? • A Duhring Diagram shows the relationship between the vapour pressure and LiBr solution with respect to pressure,temperature and concentration of LiBr,at equilibrium
  • 8. 9
  • 9. 10 c C d a b j i 58 6 4.5 38 95 TEMPERATURE ( DEG C) Absorber (j-b) Absorber (a-b) Evaporator a Condenser (d-i) REFRIGERANT CYCLE ABSORBENT CYCLE DUHRING DIAGRAM FOR S.E M/C c Gen (c -d) 68 40 55
  • 10. 11 PRESSURE PROFILES • DOUBLE EFFECT LOWER SHELL - 6 mm Hg HIGH TEMPERATURE GENERATOR - 707 mm Hg LOW TEMPERATURE GENERATOR / CONDENSER - 58 mm Hg • SINGLE EFFECT LOWER SHELL - 6 mm Hg UPPER SHELL - 70 mm Hg
  • 11. 12 PRESSURE PROFILES • DOUBLE EFFECT LOWER SHELL - 6 mm Hg HIGH TEMPERATURE GENERATOR - 707 mm Hg LOW TEMPERATURE GENERATOR / CONDENSER - 70 mm Hg • SINGLE EFFECT LOWER SHELL - 6 mm Hg UPPER SHELL - 58 mm Hg
  • 12. 13 HOW DOES THE VAPOUR ABSORPTION CREATE AND MAINTAIN VACUUM
  • 13. 14
  • 14. 15 COEFFICIENT OF PERFORMANCE • Coefficient of Performance(COP) is the measure of efficiency in a heat pump or refrigerating machine. • COP = Refrigeration effect/Heat input • COP for different types of Heat Pumps are as follows :- Double effect type = 1.2 Single effect type = 0.65 - 0.7
  • 15. 16 Materials used in VAM/cs • Tubes – Evaporator, Absorber, Condensor – High Temperature Generator Steam and Heat Reclaimer (DE only) – Low Temperature Generator (only DE) – Heat Exchanger High (only DE) – Heat Exchanger Low
  • 16. 17 Materials used in VAm/cs • Plates – Shells, Tube sheets and boxes • Valves – Angle, Service, Check, Dampers • Trays and Eliminators
  • 17. 18 Tubes in Evaporator , Absorber, Condensor - • Standard - DLP Grade Copper seamless • 16 or 19 OD, 0.6 mm thk • Standards - JIS H 3300 - C1201T 1/2H or [ASTM B 75] • Deoxidised Low Phosphorous • Cu - 99.90 min • P - 0.004 to 0.010 • Non standard - CuNi 90/10, CuNi 70/30, SS 316L, Titanium
  • 18. 19 Tubes in High Temperature Generator and Heat Reclaimer • Ferritic Stainless Steel - SS 430 Ti, SA 268 - Grade TP 430 Ti • C- 0.1, Mn 1.00, P-0.040, S-0.030, Si- 1.00, Ni-0.75 max,Cr 16.00-19.50, Ti- 5xC min, 0.75 max • 19 OD, 1mm thk -Welded • Ti grade for improved welding yield • Coefficient of Thermal Expansion close to that of CS - No stresses developed at operating temperature
  • 19. 20 Tubes in Low Temperature Generator (only DE) • DLP Grade Copper seamless • 19.05 OD and 1.42 thk
  • 20. 21 Tubes used in Heat Exchanger High • Spiral tubes of CuNi 90/10 material • OD 9.5mm and thickness 0.5mm • Spiralling done to increase turbulence thereby increasing heat transfer
  • 21. 22 Tubes used in Heat Exchanger Low • Spiral tubes of DLP grade Copper • OD 9.5mm and thickness 0.5mm • Spiralling done to increase turbulence thereby increasing heat transfer
  • 22. 23 Steel plates for shells, tube sheets and boxes • IS 2062 Gr B • Option : SA 515/516 Grade 60 or 70 • Carbon Steel - C - 0.2 % • Sulphur and Phosphorous controlled • Manganese added for stabilization
  • 23. 24 Valves - Angle, Service, Check, Dampers • SS 304 and carbon steel • Gaskets - Viton, Valvelon
  • 24. 25 Trays and Eliminators • SS 430 - 0.3 and 0.8 mm thk
  • 26. 27 DOWN VALVE REFRIGERANT PUMP ABSORBENT PUMP REFR BLOW PUMP PURGE GENERATOR CONDENSER LOW TEMP HEAT EXCHANGER OVER FLOW PIPE STEAM CONTROL VALVE ProChill Series Flow Cycle Single Effect Steam Driven
  • 27. 28 SUPPLEMENTARY FIRED EXHAUST GAS DRIVEN ABSORPTION MACHINE FIG. N0. 8
  • 28. 29 STEAM DRIVEN SINGLE DOUBLE EFFECT ABSORPTION MACHINE FIG. NO. 9
  • 29. 30 SUPPLIMENTARY FIRED EXHAUST GAS DRIVEN SINGLE DOUBLE EFFECT ABSORPTION MACHINE FIG. NO. 10
  • 30. 31
  • 31. 32
  • 32. 33 TWIN HOT WATER MACHINE TWIN HOT WATER MACHINE 90 33 3333 33 33 33 33 90 76 75 34 35 15 8 Low conc ,High Chw temp. zone 11 39 High conc, Low Chw temp.zone
  • 33. 34 SOLENOID VALVE REFRIGERANT PUMP ABSORBENT PUMP PUMP PURGE LTG CONDENSER LOW TEMP HEAT EXCHANGER OVER FLOW PIPE HEAT RECLAIMER TEMPERATURE GENERATOR HIGH EXCHANGER HIGH TEMP HEAT STEAM CONTROL VALVE Dou ble Effect Steam Fir ed Cycle Diagr am REF BLOWDOWN VALVE
  • 35. 36 BURNERS The burner operates by sucking in the fuel and combustion supporter air, mixes them thoroughly together and safely ignites them inside the heat generator furnace. BURNER PARTS 1) COMBUSTON HEAD: Fuel + Air Creates Flame 2] AIR SUPPLY : Fan + Pipes ( for taking air to combustion head) 3] FUEL SUPPLY : Fuel flow & Safety of combustion system 4] ELECTRICAL : Control Components ( req. for flame & motor)
  • 36. 37 Gaseous fuels and Burners Gas burners can be classified as follows: • Natural draught burners • Induced draught burners • Forced draught burners Natural Draught Burners - burner uses fuel gas supply pressure to pull air through Venturi sys. - burners can be extremely sensitive to combn chamber. - primary air can reach up to 50%.
  • 37. 38 Induced Draught Burners - burners are used, with a fan fitted up-stream or down- stream from combustion chamber. - primary air can reach up to 100% Forced Draught Burners - air flow rate is guaranteed by elevated head pressure fans. - draught operating condition more or less independent of burner operation. - possible to operate with low excess air & increases combustion efficiency.
  • 38. 39 Liquid fuels and Burners Liquid burners can be classified as: • Mechanical atomization • Pneumatic atomization • Centrifugal atomization Mechanical atomization - atomization is a result of mechanical pressure exerted on the liquid , when it reaches the atomizing nozzle. - fuel oil is split into great deal of extremely small droplets., size of drops depends upon exerted pressure.
  • 39. 40 Pneumatic atomization - atomization is a result of Pneumatic pressure exerted on the liquid , when it reaches the atomizing nozzle. - this system guarantees excellent fuel atomization levels for dense fuel oils - complicated structure & higher installation cost. Centrifugal atomization - drops of fuel are formed by applying a centrifugal force to liquid fuels. - liquid fuel must have sufficiently low viscosity.
  • 40. 41 • The viscosity required for obtaining sufficient fuel oil atomization varies according to the type of burner. • The nozzle required oil viscosity between 6 - 40 Cts at 50 O C in relation to the type of fuel. • This viscosity value determines the pre-heating temp value e.g. supposing we use a fuel oil with viscosity of 150 Cts at 50 O C , to obtain the value of 17 Cts needed by the nozzle to obtain the right atomization, the fuel must be preheated to a temperature between 90 to 100 O C.
  • 41. 42 Force Draught Burners (Classification based on construction ) Mono-block Dual Block Fan + Pump Fan + Pump are integral part are not integral of burner forming part of burner & a single stage body. Forms a separate part of burner
  • 42. 43 Force Draught Burners (Classify depends upon output delivery ) • Single stage burners : Operates with single stage delivery, fuel delivery is invariable and burner con be switched on or off (ON-OFF). T Start up Start up Stop Stop
  • 43. 44 Force Draught Burners (Classify depends upon output delivery ) • Multi- stage burners : Usually two- stage or three-stage , are set for running at one or more reduced out put speeds or at maximum out put (OFF-LOW- HIGH or OFF-LOW-MID-HIGH) • switch over from one stage to another can be automatic or manual T Start up 1st stage Start up 2st stage Stop 2st stage Stop 2st stage Start up 2st stage Stop 2st stage P
  • 44. 45 Force Draught Burners (Classify depends upon output delivery ) • Modulating burners : Delivery output is automatically varied continuously between a minimum and maximum , for optimum delivery of the thermal output in relation to system requirements. T Start up Stop P
  • 45. 46 BURNERS • ACD - VAMS USE EITHER OF THE FOLLOWING BURNERS • A) Nu-Way - For L Series • B) Riello- For M series • C) Bentone For earlier M series Machines • Classification of Burners : • A) Out put Delivery • Single Stage Burners
  • 46. 48 Classification • Monoblock Burners : Pump and fan are integral part forming a single body. • Dual Block : Fan, pump and othe parts are separate from main Body • Basic Parts: • Burner Body Housing : Diffuser Plate, Ignition electrodes , flame sensor, Combustion Head , with Nozzle assembly, Cone etc.
  • 47. 49 • Other parts : Pump, Blower, Pressure gages etc are mounted depending on the constructions. • Control Panel: Includes Sequence Controllers,Ignition transformer relays etc. • Fuels : HSD/Kerosene/GAS • For Smaller range of burners Pump pressure can vary from 11 to 15 kg/cm^2g.
  • 48. 50 • Typical Values of combustion Parameters(OIL) • O2 3.0% • Co2 13% • Co Below 50 ppm • Typical Values of combustion parameters (GAS)
  • 49. 51 • Oxygen O2 3.0 % • Carbon dioxide : 10 % • Carbon Monoxide : Below 50 % • Nozzles: Monarch or Danfoss • Nozzles are rated at 100 Psi • Selection Criteria for burners • a) Thermal Capacity at the heat generator furnace
  • 50. 52 • B) Back pressure in combustion chamber • C)Type of generator • D) Fuel • E)Burner Operation Mode
  • 51. 53 Gas burners • PRV • Multibloc/Air to Gas ratio Controller • Gas pressure switch • Solenoid Valves • Ignition electrodes
  • 52. 54 BURNER GAS VALVE TRAIN 1. Gas valve (Multibloc) 1.1Gas filter 1.2 Pressure switch, min. 1.3 Main gas valve 1.4 Pressure regulator 1.5 Gas valve, 2-stage 2. Valve leak tester (burner capacity > 1200 kW) 1. Ball valve, blow-off 2. Gas pressure switch, min. 3. Valve leak tester 4. Gas valve (DMV-D) 5. Ignition gas valve 6. Gas butterfly valve 7. Gas pressure switch, max. 8. Differential air pressure switch 2-STAGE MODULATING
  • 53. 55 COMPONENTS OF BURNER AND ITS FUNCTION • Gas Train – Pressure proving system - for checking leak tightness of valves – Main safety valve - Quick closure of gas supply in case of trip. – SKP 70 valve - Combined valve & Gas/air ratio regulator – Pilot solenoid valve & Gas governor - For establishing pilot flame – High & Low gas pressure switch - for checking minimum & maximum gas pressure conditions • Air system (Burner motor with fan): – Air damper with modulating control (cam) for controlling air flow thereby controlling gas flow. – Air pressure switch for cutting of burner in case of low air pressure • Gas flame tube & Air diffuser for creating proper mixture of gas & air for good combustion • Electrode & Transformer for initial ignition • Sequence controller for controlling time sequence of operations.
  • 56. 58 Air Damper control & Combustion control
  • 57. 59 Fault Finding instructions in Brief • BURNER MOTOR FAILS TO START – Check Burner electrical control – Check start command from Machine panel • BURNER MOTOR ONLY RUNS CONTINUOUSLY(NO FIRING) OR BURNER DOES NOT MODULATE – Check air damper control wiring and functioning • BURNER GOES TO LOCKOUT BEFORE FIRING – check functioning of Air pressure switch, Electrode and tranformer, Gas pressure, all Valve operations, Gas to air pressure ratio etc. • BURNER FIRES BUT GOES TO LOCK OUT WHEN IT MODULATES FROM LOW TO HIGH FLAME – check gas to air ratio ,Air damper setting high,main gas valve not operating etc.
  • 59. 61 CRYSTALLISATION Crystallisation of LiBr occurs when LiBr percentage in solution is more than that can be dissolved in the solution at specific temperature.
  • 60. 62 Effects of crystallisation • Less or no capacity • Indirect fired machine if generator is crystalised then tube failure due to over heating. Choking of pipe lines and heat exchangers leading to blocked flow
  • 61. 63 When crystalisation occurs? Low solubility Low solution temperature High concentration Both together
  • 62. 64 100 % 0 % 0 10 Distance from cryst. line Valve Opening Concentr ation
  • 63. 65 When crystallisation occurs? – Cooling water temperature low – Dilute solution temperature low – LTHE spray solution temperature low – Low solubility – Crystallisation •Low solution temperature
  • 64. 66 When crystallization occurs? • High concentration • Excess heat input due to – High steam pressure – Faulty control valve / control mechanism – Steam control valve bypass open – Contamination of LiBr in evaporator – Air ingrace – Low solution flow from pump – some other fault in machine due to which capacity of machine is low. – Excess load • Also combination of above will cause severe crystallization.
  • 65. 67 DOWN VALVE REFRIGERANT PUMP ABSORBENT PUMP REFR BLOW PUMP PURGE GENERATOR CONDENSER LOW TEMP HEAT EXCHANGER OVER FLOW PIPE STEAM CONTROL VALVE ProChill Series Flow Cycle Single Effect Steam Driven
  • 66. 69 Start of crystallization / minor crystallization • Pump delivers LiBr to generator • Due to minor crystallization resistance on spray side of LTHE increase • Return flow to absorber lowers • Absorber out flow > return flow(Absorber in) • Absorber level starts dropping • Less return flow means lower absorption of water vapour from evaporator • Evaporator level rises • Over flow pipe becomes hot
  • 67. 70 Starting symptoms of crystallization • Low capacity inspite of good generator temperature • Low absorber level • High evaporator level • Overflow pipe hot
  • 68. 71 Major crystallization • Absorber becomes empty • solution flow to generator reduces drastically • Due to low capacity high chilled water temperature • Control valve opens - full heat to generator • Low dilute flow to generator means no dilution force in generator inspite of full heat • Concentration shoots up very fast • Major crystallization
  • 69. 72 PREVENTIVE MEASURES • Low cooling water cut out • High generator temperature • Adequate refrigerant level (25% insight glass at full load) • Over flow pipe
  • 70. 73 Limitation of above preventive measures • Generator temperature senses temperature (indirectly concentration) • Crystallization depends on both concentration and temperature • At low cooling water temperature generator temperature is low even at high concentration. • Air ingrace / contamination results in rapid absorber depletion • Empty absorber stops diluting LiBr in generator • Thus crystallization cannot be avoided completely though in many cases it may avert.
  • 71. 74 Thermax’s New Crystallization free feature What is the solution?
  • 72. 75 CRYSTALLIZATION FREE MACHINE • Thermax technology - developed sophisticated computer program that calculates concentration of LiBr • PLC will check the distance of solution state point from crystallization line and operate steam control valve to avoid crystallization • Signal given to steam control valve by crystallization software will override chilled water temperature signal for valve opening • If level in absorber drops to 25% automatic blow down will dilute LiBr • If level in absorber becomes very low steam control valve will close.
  • 73. 76 CRYSTALLIZATION FREE MACHINE This way crystallization can never never occur.
  • 75. 78 B4K CYCLE DHE LTHE HR HTHE HTG TRAP CONDENSATE OUT 95°C 170°C 107°C 39°C 43°C 70°C 80°C 130°C FLOW 100% LTHE HTHE HTG CONDENSATE OUT 95°C 170°C 39°C 70°C 140°C 170°C 145°C HR DHE 39°C 74°C NEEDLE VALVE S OLD CYCLE FLOW 15% Ball Valve
  • 76. 79 SOLENOID VALVE REFRIGERANT PUMP ABSORBENT PUMP PUMP PURGE LTG CONDENSER LOW TEMP HEAT EXCHANGER OVER FLOW PIPE HEAT RECLAIMER TEMPERATURE GENERATOR HIGH EXCHANGER HIGH TEMP HEAT STEAM CONTROL VALVE Dou ble Effect Steam Fir ed Cycle Diagr am REF BLOWDOWN VALVE
  • 77. 80 PREVENTIVE MAINTENANCE • 750 HOURS OF OPERATION: – Check oil of Vacuum pump and change if required • 2000 HOURS OF OPERATION – Check working of safety devices – Check currents of all motors – Check combustion analysis – Note the readings in the performance report (all temperatures of various parts as mentioned in the report) – Collect sample of Lithium Bromide ( after running the machine in heater mode for 2 hours) for analysis of : • Inhibitor level • Alkalinity
  • 78. 81 PREVENTIVE MAINTENANCE • 8000 HOURS OF OPERATION – Overhaul vacuum pump – Charge Nitrogen and keep the machine under a slight positive pressure ( say 0.1 bar) – Check Evaporator / Absorber / Condenser tubes. Clean if required. Use only Nylon brushes for cleaning – Check Economiser tubes foar any carbon deposit – Replace diaphragm of purge valves . After the replacement and cleaning of tubes carry out nitrogen pressure test. – Replace UV cell of burner.
  • 79. 82 MAINTENANCE PROCEDURE • Make -up of Lithium Molybdate is required: – Vacuum leakage has occured – Repair of machine had been done after opening the machine to atmospheric pressure. – Loss of inhibitor in the form of non-condensables over a period of time and Analysis results shows inhibitor level is less. • Method of addition of Lithium Molybdate : – Should be charged only when the machine is running in cooling mode. Keep the vacuum pump in operation while charging. – Charging should be done through the service valve on refreigerant pump discharge. – Charging should be done very slowly (at the rate of 1 litre/minute). Just open the service valve slowly until it starts sucking. Do not open more than that. – Machine should be run in Cooling mode for atleast 2 hours after charging.
  • 80. 83 Procedure for storage with water in the circuit: Drain the dirty water from the header circuit. Do auxiliary washing of circuit from a location higher than machine. Fill at once with clean water, and operate the cooling / hot water pump and drain once again (30 min.~ 1 hour) after circulation washing. Fill with clean water once again. Maintain in the same condition.
  • 81. 84 Note: At the time of maintenance operation, the temperature of cooling / hot water system, with water inside the machine, increases above 90oC. Because hot water inside expands, the pressure inside increases. To relieve the pressure, crack open the air vent valve on the outlet of the machine.
  • 82. 85 Procedure for storage w/o water in the circuit: Drain the dirty water from the header circuit. Do auxiliary washing of circuit from a location higher than machine. Fill at once with clean water, and operate the cooling / hot water pump and drain once again [ 30 min~1 hour ] after circulation washing. Maintain in the same condition.
  • 83. 86 Function of Octyl alcohol: Surface active agent in the absorber, results in better wettability and heat transfer. (Marangonie Effect) Refrigerant vapour Tube Soln concentration becomes uniform at this point
  • 85. 88 Sequence • Thermax Introduction • History of Absorption Cycles • Compression and Absorption - Comparison • Explanation of Operating Cycle • Machine Illustration • Control System and Safety Features • Manufacturing and Component Features • Options - fuels etc • Application possibilities • Reference Installations • Feasibility Analysis • Summing up
  • 86. 89 Thermax Introduction • An Energy and Environment Company • 1500 people • 3 Core Business Areas – Cooling and Heating Products – Boilers, Heaters, Power, and Environmental Projects – Water and Waste water and Chemicals • India’s largest Absorption manufacturer International presence • 51,345 sq m of manufacturing space • Sales of 1200 Cr
  • 87. 90 History of Absorption Refrigeration • Cycle invented by Ferdinand Carre in 1846 • Ammonia as refrigerant and water as absorbent, at two pressure levels • Single pressure level cycle invented in 1922 by Munters and Platen • Considered useful only if waste was available • Invention of GAX cycle to improve efficiency • Resurgence of Ammonia Absorption as – Hydrocarbon fuels become expensive – Heat recovery applications become attractive – Solid fuel shift
  • 88. 91 Compression and Absorption - Comparison • Compressor is replaced by a combination of absorber, solution pump and generator Condenser Compressor High Pr Heat Evaporator Low Pr. Heat Condenser High Pr Heat Evaporator Low Pr. Heat Generator Absorber
  • 89. 92 BASIC OPERATING CYCLE Condenser Heat Exchanger Stripping Colm Rect Colm Partial Condenser Evaporator Cond Out In Out In Out In Out Expansion Valve Expansion Valve Cooling Water Cooling Water Cooling Water Brine Solution Pump Generator Steam In Subcooler In Out Bleed HE Absorber Animate
  • 90. 93 Machine Illustration Condenser and buffer tank Absorber Stripping Column Rectification column Evaporator Partial condenser Heat Exchanger Generator Solution Pump Sub-cooler
  • 91. 94 Utility Consumption • Steam Consumption – Evaporation Temp Steam Consumption – - 5 °C 9.25 kg/hr/TR – -15 °C 10.3 kg/hr/TR – -25 °C 11.75 kg/hr/TR • Cooling Water Requirement – Evaporation Temp CW Consumption – - 5 °C 1.55 m3/hr/TR – -15 °C 1.85 m3/hr/TR – -25 °C 1.96 m3/hr/TR
  • 92. 95 Minimum Steam Pressure Required – Evaporation Temp Steam Pressure – - 5 °C 2 kg/cm2g – -15 °C 3 kg/cm2g – -25 °C 5 kg/cm2g
  • 93. 96 Control system and Safety features • Fully automatic operation • Modulating Turndown from 100% to 10% • PLC control panel • LCD Operator Interface • 3 PID loops – Generator temperature control – Absorber solution flow control – Generator solution flow control • Pressure, temperature, flow, and level safeties • Relief valves on high and low side
  • 94. 97 Manufacturing and Component Features • Design of pressure vessels to ASME Sec VIII • ISO 9001 and ISO 14001 certified manufacturing • Heat exchangers sized for high efficiency • Compact design • Modularized design for quick installation • Stainless steel column internals for long life • Stainless steel solution distribution system • High Efficiency Grundfos solution pump • Standby pump for high availability
  • 95. 98 Options – fuels etc • Direct fired – Gas and Liquid fuel units • Genset Exhaust gas fired units • Optional partial condenser temperature control • Process integrated controls • Special tube metallurgy – SS, Ti etc possible • Two evaporation level systems • Integrated Ammonia and Brine systems
  • 96. 99 GAX Cycle Overview • Applicable above -5°C • Min Steam Pressure required : 9 kg/cm2g • Strong Aqua ammonia in heat exchange with weak aqua ammonia in the absorber • Weak aqua concentration : 10 % • Strong aqua concentration : 40 % • Steam consumption : 8 kg/hr/TR
  • 97. 100 Application possibilities • Brine systems – Reactor Cooling etc • Ammonia systems – Process chillers – Ice bank tanks – Ice block manufacture – Cold storages – Food processing – etc
  • 98. 101 Reference Installations - by Application / Industry • Process Integrated – HWB Heavy Water plant - Tuticorin – HWB Heavy Water plant - Baroda • Chemicals – - Shriram Fertilizers and Chemicals (DSCL) – - Sajjan India • Pharmaceutical – - Dishman Pharma • Dairy – - Milkfood Limited • Cold Storage – - JR Agro
  • 99. 102 Feasibility Analysis 200 TR - Steam fired AVAM (-25°C evaporation) Re. DESCRIPTION Unit Comp. AVAM 1 Capacity TR 200 200 2 Power consumption Unit kW 360.0 18.0 CW circuit kW 12.5 27.5 Cooling tower fan kW 4 10 3 Steam Consumption Unit kg/hr 0 2400 4 Total Operational Costs Power cost Rs. per kW Rs / kW 4.5 4.5 Steam cost per kg Rs / kg 0.45 0.45 Total Cost of Running - 8000 Hrs Rs lacs 135.5 106.4 5 Net Savings per annum Rs lacs 29.2
  • 100. 103 Summing Up • Replacement Cases – - Payback in 2 years • New Facility – - Payback in 6 months
  • 101. 104 BASIC OPERATING CYCLE Condenser Heat Exchanger Stripping Colm Rect Colm Partial Condenser Evaporator Cond Out In Out In Out In Out Expansion Valve Solution Control Valve Cooling Water Cooling Water Cooling Water Brine Solution Pump Generator Steam In In Out Absorber Bleed HE Subcooler Exit