Composite lithium bromide absorption type cold water or hot water unit

Abstract

The invention relates to a composite lithium bromide absorption type cold water or hot water unit, which is characterized in that a refrigeration evaporator, a refrigeration absorber and a refrigeration solution heat exchanger are additionally arranged on the basis of a second-class lithium bromide absorption type heat pump unit for producing high-temperature hot water and single-effect circulation, and the refrigeration evaporator and the refrigeration absorber are arranged at the lower part of the unit; the generator and the condenser are common parts for refrigerating circulation and heating circulation. The refrigerating capacity and the heating capacity of rated working conditions can be achieved when refrigerating and heating of the unit are operated at the same time, the heating load can be increased when the refrigerating load is reduced, and the heating capacity of independent heating operation can reach the maximum value when refrigerating is stopped. Therefore, the unit disclosed by the invention can simultaneously meet the requirements of users for refrigerating water and heating water, and can reduce the initial investment cost, save the equipment management cost and save the equipment occupied space.

Description

Technical Field

[0001] This invention relates to the field of refrigeration equipment technology, specifically to a composite lithium bromide absorption chiller or hot water unit. Background Technology

[0002] In production processes and daily life, both cooling and heating are often required. In situations with medium-temperature waste heat sources, for energy conservation and environmental protection, hot water type lithium bromide absorption chillers (such as...) need to be installed for cooling in summer. Figure 1 (This is a schematic diagram of the working principle of one type of single-effect cycle process of the unit). To produce a heating unit with a temperature higher than the waste heat source, a second type of lithium bromide absorption heat pump unit needs to be built (such as...). Figure 2 (This is a working principle diagram of a single-effect circulation process for producing high-temperature hot water in this unit.) This requires the construction of two types of equipment, which will inevitably increase the initial investment and management costs. In order to meet the demand for simultaneous cooling and heating on the same unit, reduce the initial investment, lower operating and management costs and equipment footprint, and fully recover waste heat to produce more heat, it is necessary to research a composite lithium bromide absorption chiller or hot water unit that is energy-saving, environmentally friendly, safe and reliable, and capable of both cooling and heating. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a composite lithium bromide absorption chiller or hot water unit that can simultaneously cool and heat, or heat independently. This reduces initial investment in equipment, lowers operating and management costs and equipment footprint, and allows for the recovery of more waste heat to produce more heat.

[0004] The objective of this invention is achieved as follows: A composite lithium bromide absorption chiller or hot water unit includes a generator, condenser, heating evaporator, heating absorber, heating solution heat exchanger, heating concentrated solution pump, heating evaporator refrigerant circulation pump, and heating condenser refrigerant water pump for forming a heat pump cycle. It also includes a refrigeration evaporator, a refrigeration absorber, and a refrigeration solution heat exchanger. The refrigeration evaporator and refrigeration absorber are housed in the same cavity and located at the bottom of the unit. The generator, condenser, refrigeration evaporator, refrigeration absorber, refrigeration solution heat exchanger, refrigeration dilute solution pump, and refrigeration evaporator refrigerant circulation pump constitute a refrigeration cycle. The generator and condenser are shared components for both the refrigeration and heating cycles. At the bottom of the concentrated solution bladder of the generator, there are parallel cooling concentrated solution generator pipelines and heating concentrated solution pumps. A concentrated solution bypass pipeline is provided between the concentrated solution pipeline of the heating concentrated solution heat exchanger and the cylinder of the cooling absorber, and a concentrated solution bypass valve is provided on it. A cooling concentrate switching and regulating valve is installed on the pipeline of the cooling concentrate generator; A dilute solution bypass pipeline is provided between the dilute solution outlet pipeline of the refrigeration solution heat exchanger and the concentrated solution pipeline after the refrigeration concentrated solution switching regulating valve, and a dilute solution bypass valve is provided on the dilute solution bypass pipeline; A dilute solution pump is installed at the bottom of the dilute solution bladder of the refrigeration absorber, and a dilute solution switching valve is installed on the pipeline before the dilute solution enters the generator.

[0005] Preferably, the refrigerant water tank of the condenser is provided with a parallel refrigerant water U-tube and a condenser refrigerant water pump for heating, the refrigerant water U-tube is provided with a refrigerant water switching regulating valve, and a refrigerant cooling water switching regulating valve is provided on the cooling water pipeline of the cooling water entering the refrigeration absorber.

[0006] Preferably, the dilute solution bladder of the refrigeration absorber is provided with a refrigeration dilute solution level electrode, the refrigerant water bladder of the refrigeration evaporator is provided with a refrigeration refrigerant water level electrode, the bottom concentrated solution bladder of the generator is provided with a concentrated solution level electrode, the refrigerant water bladder of the condenser is provided with a condenser refrigerant water level electrode, and the dilute solution bladder of the heating absorber is provided with a heating dilute solution level electrode.

[0007] Preferably, the dilute refrigeration solution pump lifts the dilute refrigeration solution according to the dilute refrigeration solution level electrode signal, and the solution is heated by the refrigeration solution heat exchanger before entering the dilute refrigeration solution distribution pipe of the generator; the concentrated heating solution pump lifts part of the concentrated heating solution according to the concentrated heating solution level electrode signal, and the solution is heated by the concentrated heating solution heat exchanger before entering the concentrated heating solution distribution pipe of the heating absorber; the amount of refrigerant water entering the refrigeration evaporator is adjusted according to the refrigerant water level electrode signal; and the refrigerant water pump for the heating condenser pump pumps part of the refrigerant water into the heating evaporator according to the refrigerant water level electrode signal for the condenser.

[0008] Preferably, in summer, when the refrigeration cycle and the heating cycle are running simultaneously, the concentrated solution bypass valve and the dilute solution bypass valve are in the closed state, the refrigeration dilute solution switching valve is in the open state, and the refrigeration concentrated solution switching regulating valve, the refrigeration refrigerant water switching regulating valve and the refrigeration cooling water switching regulating valve are all in the open state. During the early and late summer, when refrigeration requires reduced load operation, the switching valves for the concentrated refrigeration solution, refrigerant water, and cooling water can adjust their openings to change the medium flow rate according to the required refrigeration load. The control system reduces the amount of refrigerant and solution in the refrigeration cycle and increases the amount of refrigerant and solution in the heating cycle accordingly, thereby increasing the heating load and heating capacity.

[0009] Preferably, in spring, autumn, and winter, when the refrigeration cycle needs to be stopped but the heating cycle still needs to run, firstly, the concentrated refrigeration solution switching regulating valve, the dilute refrigeration solution switching valve, and the refrigerant water switching regulating valve are closed, and the dilute solution bypass valve is opened. The refrigeration cycle enters the automatic shutdown dilution operation state. The cooling water switching regulating valve is closed. When the concentration of the concentrated refrigeration solution is detected to be ≤57%, the dilution operation ends, the dilute refrigeration solution pump and the refrigerant circulation pump of the refrigeration evaporator stop, and the refrigeration cycle can be safely stopped. At this time, the control system gradually increases the amount of refrigerant and the solution circulation volume of the heating cycle to the maximum design value, and the heating load reaches the maximum heating capacity.

[0010] Preferably, when the heating cycle is running and the cooling cycle is stopped and needs to be started, first, open the cooling water switching regulating valve, open the concentrated refrigerant switching regulating valve, the dilute refrigerant switching valve and the refrigerant water switching regulating valve, and close the dilute solution bypass valve to start the refrigeration cycle.

[0011] Preferably, during the refrigeration cycle operation, when it is determined that the concentrated solution in the refrigeration solution heat exchanger has crystallized, the concentrated solution bypass valve is opened to allow the high-temperature concentrated solution to bypass into the bottom of the refrigeration absorber, thereby raising the temperature of the dilute solution. The high-temperature solution enters the refrigeration solution heat exchanger to heat the concentrated solution and gradually decrystallize it. After the crystallization is resolved, the concentrated solution bypass valve can be closed.

[0012] Preferably, when the liquid level electrode of the dilute refrigeration solution indicates a low liquid level and the liquid level electrode of the concentrated solution indicates a high liquid level, it can be determined that the concentrated solution in the refrigeration solution heat exchanger has crystallized.

[0013] Preferably, when both the refrigeration and heating cycles are running and need to be stopped simultaneously, to prevent low-temperature crystallization of the concentrated solution circulation system after shutdown, the control system automatically shuts down both the refrigeration and heating cycles to dilution operation without valve operation. When the concentration of the concentrated solution is detected to be ≤57%, the dilution operation ends, and both the refrigeration and heating cycles can be safely stopped.

[0014] The beneficial effects of this invention are: Through the aforementioned new processes, structural forms, and valve switching and adjustment, the refrigeration cycle and heating cycle can be realized on the same unit, which can reduce material costs, reduce initial equipment investment, save equipment space, ensure safe, stable and reliable operation of the unit, save equipment management costs, and improve the annual operating utilization rate of the unit. When designing the unit, based on the external parameters and rated load requirements provided by the user, the optimal solution concentrations for both cooling and heating modes can be determined. This allows for the selection of the same dilute solution concentration for cooling mode and heating mode, and vice versa. The required heat exchange area for each component under rated operating conditions is then determined for both cooling and heating modes. Since the generator and condenser are shared components for both cooling and heating cycles, their heat exchange areas are the sum of their respective rated heat exchange areas required for simultaneous operation of the cooling and heating cycles. The heat exchange areas for the evaporator and absorber are the rated heat exchange areas during the cooling cycle. To maximize waste heat recovery and heat production, the heat exchange areas for the evaporator and absorber are the heat exchange areas that maximize heat production while fully utilizing and matching the total heat exchange areas of the generator and condenser. This ensures that the unit can achieve its rated cooling and heating capacity when operating in both cooling and heating modes simultaneously. It also allows the heating load to increase when the cooling load is reduced, and the heating capacity to reach its maximum when cooling is stopped. This maximizes the recovery of waste heat, making it highly energy-efficient and environmentally friendly, and providing excellent economic and social benefits. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the working principle of a single-effect circulation process for one type of solution in a hot water type lithium bromide absorption chiller.

[0016] Figure 2 This is a schematic diagram of the working principle of a single-effect circulation process for producing high-temperature hot water in one type of lithium bromide absorption heat pump unit of the second category.

[0017] Figure 3 This invention provides a flow chart for a composite lithium bromide absorption chiller or hot water unit.

[0018] The components include: 1. Refrigeration evaporator; 2. Refrigeration absorber; 3. Refrigerant concentrated solution outlet generator pipeline; 4. Dilute solution bypass valve; 5. Heating concentrated solution pump; 6. Refrigerant concentrated solution switching regulating valve; 7. Refrigerant dilute solution switching valve; 8. Heating solution heat exchanger; 9. Concentrated solution bypass valve; 10. Concentrated solution level electrode; 11. Generator; 12. Condenser; 13. High-temperature hot water inlet; 14. Heating evaporator refrigerant circulation pump; 15. Heating dilute solution level electrode; 16. Heating evaporator; 17. Heating absorber; 18. High-temperature hot water outlet; 19. Refrigerant... 20. Dilute solution distribution pipe; 21. Heating dilute solution distribution pipe; 22. Waste hot water outlet; 23. Cooling water outlet; 24. Cooling water inlet; 25. Condenser refrigerant water level electrode; 26. Heating condenser refrigerant water pump; 27. Cold water outlet; 28. Cold water inlet; 29. ​​Refrigerant water U-tube; 30. Refrigerant water switching regulating valve; 31. Refrigerant cooling water switching regulating valve; 32. Refrigerant water level electrode; 33. Refrigerant circulation pump for evaporator; 34. Refrigerant dilute solution pump; 35. Refrigerant dilute solution level electrode; 36. Refrigerant solution heat exchanger. Detailed Implementation

[0019] See Figure 3 This invention relates to a composite lithium bromide absorption chiller or hot water unit, comprising a generator 11, a condenser 12, a refrigeration evaporator 1, a refrigeration absorber 2, a refrigeration solution heat exchanger 36, a heating evaporator 16, a heating absorber 17, a heating solution heat exchanger 8, a dilute refrigeration solution pump 34, a refrigerant circulation pump 33 for the refrigeration evaporator, a concentrated heating solution pump 5, a refrigerant circulation pump 14 for the heating evaporator, a refrigerant water pump 26 for the heating condenser, and connecting pipes, valves, level electrodes, and a control system between the components. The unit is powered by the generator 11, condenser 12, heating evaporator 16, heating absorber 17, heating solution heat exchanger 8, concentrated heating solution pump 5, refrigerant circulation pump 14 for the heating evaporator, and refrigerant water pump 26 for the heating condenser. The water pump 26 constitutes a second-type lithium bromide absorption heat pump unit with a single-effect cycle for producing high-temperature hot water. The refrigeration evaporator 1 and refrigeration absorber 2 are placed at the bottom of the second-type lithium bromide absorption heat pump unit. The refrigeration cycle consists of a generator 11, a condenser 12, a refrigeration evaporator 1, a refrigeration absorber 2, a refrigeration solution heat exchanger 36, a refrigeration dilute solution pump 34, and a refrigeration evaporator refrigerant circulation pump 33. The heating cycle consists of a generator 11, a condenser 12, a heating evaporator 16, a heating absorber 17, a heating solution heat exchanger 8, a heating concentrated solution pump 5, a heating evaporator refrigerant circulation pump 14, and a heating condenser refrigerant water pump 26. The generator 11 and the condenser 12 are shared components of the refrigeration cycle and the heating cycle.

[0020] The generator 11 is equipped with a cooling dilute solution distribution pipe 20 and a heating dilute solution distribution pipe 21, respectively, and both the cooling dilute solution and the heating dilute solution enter the generator's spray plate for distribution.

[0021] The dilute solution bladder of the refrigeration absorber 2 is provided with a refrigeration dilute solution level electrode 35, the refrigerant water bladder of the refrigeration evaporator 1 is provided with a refrigeration refrigerant water level electrode 32, the bottom concentrated solution bladder of the generator 11 is provided with a concentrated solution level electrode 10, the refrigerant water bladder of the condenser 12 is provided with a condenser refrigerant water level electrode 25, and the dilute solution bladder of the heating absorber 17 is provided with a heating dilute solution level electrode 15.

[0022] A dilute solution pump 34 is installed at the bottom of the dilute solution bladder of the refrigeration absorber 2. The dilute solution pump 34 lifts the dilute solution according to the signal of the dilute solution level electrode 35, and heats it through the refrigeration solution heat exchanger 36 before entering the dilute solution distribution pipe 20 of the generator 11. A dilute solution switching valve 7 is installed on the pipeline before the dilute solution enters the dilute solution distribution pipe 20 of the refrigeration generator.

[0023] At the bottom of the concentrated solution bladder of the generator 11, there are parallel cooling concentrated solution outlet generator pipes 3 and heating concentrated solution pumps 5. The cooling concentrated solution flows by gravity through the cooling solution heat exchanger 36 to cool down and enters the cooling absorber 2 for distribution. The heating concentrated solution pump 5 lifts part of the heating concentrated solution according to the signal of the heating dilute solution level electrode 10, and heats it through the heating solution heat exchanger 8 before entering the heating absorber 17 for distribution. A concentrated solution bypass pipe is provided between the concentrated solution outlet pipe of the heating solution heat exchanger 8 and the cylinder of the cooling absorber 2, and a concentrated solution bypass valve 9 is provided on it. A cooling concentrated solution switching regulating valve 6 is provided on the cooling concentrated solution outlet generator 11 pipe. A dilute solution bypass pipe is provided between the cooling dilute solution outlet pipe of the cooling solution heat exchanger 36 and the concentrated solution pipe after the cooling concentrated solution switching regulating valve 6, and a dilute solution bypass valve 4 is provided on the dilute solution bypass pipe.

[0024] The condenser 12 has a refrigerant water U-shaped pipe 29 and a heating condenser refrigerant water pump 26 arranged in parallel on the refrigerant water tank. The refrigerant water U-shaped pipe 29 is equipped with a refrigerant water switching regulating valve 30, which can adjust the amount of refrigerant water entering the evaporator 1 according to the signal of the refrigerant water level electrode 32. The heating condenser refrigerant water pump 26 pumps part of the refrigerant water into the heating evaporator 16 according to the signal of the condenser refrigerant water level electrode 25.

[0025] A cooling water switching regulating valve 31 is installed on the cooling water pipeline into the refrigeration absorber 2.

[0026] In summer, when the refrigeration and heating cycles operate simultaneously, the concentrated solution bypass valve 9 and the dilute solution bypass valve 4 are closed, the refrigeration dilute solution switching valve 7 is open, and the refrigeration concentrated solution switching regulating valve 6, the refrigerant water switching regulating valve 30, and the refrigeration cooling water switching regulating valve 31 are all open. At the beginning and end of summer, when the refrigeration needs to be reduced in load, the refrigeration concentrated solution switching regulating valve 6, the refrigerant water switching regulating valve 30, and the refrigeration cooling water switching regulating valve 31 can adjust the valve opening to change the medium flow rate according to the required refrigeration load. The control system reduces the amount of refrigerant and solution in the refrigeration cycle and increases the amount of refrigerant and solution in the heating cycle accordingly, thereby increasing the heating load and the heating capacity.

[0027] In spring, autumn, and winter, when the refrigeration cycle needs to be stopped but the heating cycle still needs to run, firstly, close the refrigeration concentrated solution switching regulating valve 6, the refrigeration dilute solution switching valve 7, and the refrigerant water switching regulating valve 30, and open the dilute solution bypass valve 4. The refrigeration cycle enters the automatic shutdown dilution operation state. Close the refrigeration cooling water switching regulating valve 31. When the concentration of the refrigeration concentrated solution is detected to be ≤57% (to prevent solution crystallization), the dilution operation ends, the refrigeration dilute solution pump 34 and the refrigeration evaporator refrigerant circulation pump 33 stop, and the refrigeration cycle can be safely stopped. At this time, the control system gradually increases the refrigerant dosage and solution circulation volume of the heating cycle to the maximum design value, and the heating load reaches the maximum heating capacity.

[0028] When the heating cycle is running and the cooling cycle is stopped, and the cooling cycle needs to be started, first, open the cooling water switching regulating valve 31, open the concentrated cooling solution switching regulating valve 6, the dilute cooling solution switching valve 7 and the refrigerant water switching regulating valve 30, and close the dilute solution bypass valve 4 to start the cooling cycle.

[0029] During the refrigeration cycle, if the dilute solution level electrode 35 indicates a low level while the concentrated solution level electrode 10 indicates a high level, or for other reasons, it is determined that the concentrated solution in the refrigeration solution heat exchanger has crystallized, the concentrated solution bypass valve 9 is opened to allow the high-temperature concentrated solution to bypass into the bottom of the refrigeration absorber 2, thereby raising the temperature of the dilute solution. The high-temperature solution then enters the refrigeration solution heat exchanger 36 to heat the concentrated solution and gradually decrystallize it. After the crystallization is resolved, the concentrated solution bypass valve 9 can be closed.

[0030] When both the refrigeration and heating cycles are running and need to be stopped simultaneously, to prevent low-temperature crystallization of the concentrated solution circulation system after shutdown, the control system automatically shuts down both the refrigeration and heating cycles to dilution operation without valve operation. When the concentration of the concentrated solution is detected to be ≤57%, the dilution operation ends, and both the refrigeration and heating cycles can be safely stopped.

[0031] The detailed water system flow of the unit is as follows: When the refrigeration cycle and heating cycle are running simultaneously, cooling water enters the condenser 12 and refrigeration absorber 2 in parallel from the cooling water inlet 24 to raise its temperature. When the refrigeration cycle stops and the heating cycle is running, all the cooling water from the cooling water inlet 24 enters the condenser 12 to raise its temperature. The heated cooling water flows out of the unit from the cooling water outlet 23. Waste hot water enters the heating evaporator 16 in series from the waste hot water inlet 19 to cool down, and then enters the generator 11 to continue cooling down. The heat of the waste hot water is recovered and utilized, and it flows out of the unit from the waste hot water outlet 22. Cold water enters the refrigeration evaporator 1 from the cold water inlet 28 to release heat and cool down, becoming cold water at an even lower temperature, and flows out of the unit from the cold water outlet 27 for user use. High-temperature hot water enters the heating absorber 17 from the high-temperature hot water inlet 13 to absorb heat and raise its temperature, becoming the high-temperature hot water to be produced, and flows out of the unit from the high-temperature hot water outlet 18 for user use.

[0032] The detailed refrigeration cycle process is as follows: The dilute solution pump 34 lifts the dilute solution according to the signal from the dilute solution level electrode 35, and after being heated by the refrigeration solution heat exchanger 36, it enters the dilute solution distribution pipe 20 of the generator, and is then evenly distributed into the generator's spray plate. The dilute solution is sprayed onto the surface of the tube bundle of the generator 11, absorbing heat from the residual hot water inside the tube bundle to concentrate it into a concentrated solution, while simultaneously generating refrigerant vapor. The concentrated solution flows by gravity due to the pressure and potential difference between the chambers, is cooled by the refrigeration solution heat exchanger 36, and enters the spray plate of the refrigeration absorber 2. The refrigerant vapor enters the tube bundle of the condenser 12, where the heat is absorbed by the refrigerant vapor flowing through the tube bundle. The refrigerant water is carried out and condenses into refrigerant water. This refrigerant water flows by gravity through the refrigerant water U-shaped pipe 29 into the evaporator 1 for flashing. The unflashed refrigerant water enters the bottom of the evaporator 1. The refrigerant water is then pumped into the evaporator 1 by the refrigerant circulation pump 33 and sprayed onto the surface of the tube bundle, absorbing heat from the cold water inside the tube bundle and evaporating. The evaporated refrigerant vapor enters the tube bundle of the absorber 2 and is absorbed by the concentrated solution sprayed onto the tube bundle surface within the absorber 2's spray plate. The concentrated solution becomes a dilute solution and enters the bottom of the absorber 2. The heat released by the concentrated solution during the absorption of refrigerant vapor is carried away by the cooling water inside the absorber 2's tube bundle. This continuous cycle produces chilled water for user use.

[0033] The detailed heating cycle process is as follows: The dilute solution at the bottom of the heating absorber 17 flows by gravity due to the pressure and potential difference between the chambers, is cooled by the heating solution heat exchanger 8, and enters the heating dilute solution distribution pipe 21 of the generator. It is then evenly distributed into the generator's spray plate. The dilute solution is sprayed onto the surface of the tube bundle of the generator 11, absorbing heat from the residual hot water in the tube bundle and concentrating it into a concentrated solution, while simultaneously generating refrigerant vapor. The concentrated solution is partially lifted by the heating concentrated solution pump 5 according to the signal from the concentrated solution level electrode 10, and then heated by the heating solution heat exchanger 8 before entering the spray plate of the heating absorber 17. The refrigerant vapor enters the tube bundle of the condenser 12, where the heat is absorbed by the cooling water flowing through the tube bundle. The refrigerant vapor is carried out and condenses into refrigerant water. Based on the signal from the refrigerant water level electrode 25, the refrigerant water is pumped by the refrigerant water pump 26 of the heating condenser into the refrigerant water sac at the bottom of the heating evaporator 16. Then, the refrigerant circulation pump 14 pumps it into the spray plate of the heating evaporator 16 and sprays it onto the surface of the tube bundle, absorbing heat from the residual hot water in the tube bundle and evaporating. The evaporated refrigerant vapor enters the tube bundle space of the heating absorber 17 and is absorbed by the concentrated solution sprayed onto the surface of the tube bundle inside the spray plate of the heating absorber 17. The concentrated solution becomes a dilute solution and enters the bottom of the heating absorber 17. The heat released by the concentrated solution when absorbing the refrigerant vapor is absorbed by the high-temperature hot water in the tube bundle of the heating absorber 17. This continuous cycle recovers the heat from the residual hot water to produce high-temperature hot water for users.

[0034] In addition to the above embodiments, the present invention also includes other embodiments. All technical solutions formed by equivalent transformation or equivalent substitution should fall within the protection scope of the claims of the present invention.

Claims

1. A composite lithium bromide absorption chiller or hot water unit, comprising a generator (11), a condenser (12), a heating evaporator (16), a heating absorber (17), a heating solution heat exchanger (8), a heating concentrated solution pump (5), a heating evaporator refrigerant circulation pump (14), and a heating condenser refrigerant water pump (26) for forming a heat pump cycle, characterized in that: It also includes a refrigeration evaporator (1), a refrigeration absorber (2) and a refrigeration solution heat exchanger (36). The refrigeration evaporator (1) and the refrigeration absorber (2) are located in the same cavity and at the bottom of the unit. The generator (11), condenser (12), refrigeration evaporator (1), refrigeration absorber (2), refrigeration solution heat exchanger (36), refrigeration dilute solution pump (34), and refrigeration evaporator refrigerant circulation pump (33) constitute a refrigeration cycle. The generator (11) and the condenser (12) are shared components for the refrigeration cycle and the heating cycle. At the bottom of the concentrated solution bladder of the generator (11), there are parallel cooling concentrated solution generator pipelines (3) and heating concentrated solution pumps (5). A concentrated solution bypass pipeline is provided between the concentrated solution pipeline of the heating concentrated solution heat exchanger (8) and the cylinder of the cooling absorber (2), and a concentrated solution bypass valve (9) is provided on it. A cooling concentrate switching regulating valve (6) is provided on the pipeline of the cooling concentrate generator (11); A dilute solution bypass pipeline is provided between the dilute solution outlet pipeline of the refrigeration solution heat exchanger (36) and the concentrated solution pipeline after the refrigeration concentrated solution switching regulating valve (6), and a dilute solution bypass valve (4) is provided on the dilute solution bypass pipeline. A dilute solution pump (34) is installed at the bottom of the dilute solution bladder of the refrigeration absorber 2, and a dilute solution switching valve (7) is installed on the pipeline before the dilute solution enters the generator's dilute solution distribution pipe (20).

2. The composite lithium bromide absorption chiller or hot water unit according to claim 1, characterized in that: The condenser (12) is provided with a parallel refrigerant water U-tube (29) and a condenser refrigerant water pump (26) for heating. The refrigerant water U-tube (29) is provided with a refrigerant water switching regulating valve (30). A refrigerant water switching regulating valve (31) is provided on the cooling water pipeline into the refrigeration absorber (2).

3. A composite lithium bromide absorption chiller or hot water unit according to claim 2, characterized in that: The dilute solution bladder of the refrigeration absorber (2) is provided with a refrigeration dilute solution level electrode (35), the refrigerant water bladder of the refrigeration evaporator (1) is provided with a refrigeration refrigerant water level electrode (32), the bottom concentrated solution bladder of the generator (11) is provided with a concentrated solution level electrode (10), the refrigerant water bladder of the condenser (12) is provided with a condenser refrigerant water level electrode (25), and the dilute solution bladder of the heating absorber (17) is provided with a heating dilute solution level electrode (15).

4. A composite lithium bromide absorption chiller or hot water unit according to claim 3, characterized in that: The cooling dilute solution pump (34) lifts the cooling dilute solution according to the signal of the cooling dilute solution level electrode (35), and heats it through the cooling solution heat exchanger (36) before entering the cooling dilute solution distribution pipe (20) of the generator (11). The heating concentrated solution pump (5) lifts part of the heating concentrated solution according to the signal of the heating dilute solution level electrode (10), and heats it through the heating solution heat exchanger (8) before entering the heating absorber (17) for distribution. The amount of refrigerant water entering the evaporator (1) is adjusted according to the signal from the refrigerant water level electrode (32); The refrigerant water pump (26) for heating condenser pumps a portion of the refrigerant water into the heating evaporator (16) based on the signal from the refrigerant water level electrode (25).

5. A composite lithium bromide absorption chiller or hot water unit according to claim 2, characterized in that: In summer, when the refrigeration cycle and the heating cycle are running simultaneously, the concentrated solution bypass valve (9) and the dilute solution bypass valve (4) are closed, the refrigeration dilute solution switching valve (7) is open, and the refrigeration concentrated solution switching regulating valve (6), the refrigeration refrigerant water switching regulating valve (30) and the refrigeration cooling water switching regulating valve (31) are all open. During the early and late summer, when the refrigeration needs to be reduced in load, the refrigeration concentrated solution switching regulating valve (6), the refrigeration refrigerant water switching regulating valve (30) and the refrigeration cooling water switching regulating valve (31) can adjust the valve opening to change the medium flow according to the needs of the refrigeration load. The control system reduces the amount of refrigerant and solution in the refrigeration cycle and increases the amount of refrigerant and solution in the heating cycle accordingly, so the heating load increases accordingly and the heating capacity increases accordingly.

6. A composite lithium bromide absorption chiller or hot water unit according to claim 2, characterized in that: In spring, autumn, and winter, when the refrigeration cycle needs to be stopped but the heating cycle still needs to be run, first, close the refrigeration concentrated solution switching regulating valve (6), the refrigeration dilute solution switching valve (7), and the refrigeration refrigerant water switching regulating valve (30), and open the dilute solution bypass valve (4). The refrigeration cycle enters the automatic shutdown dilution operation state. Close the refrigeration cooling water switching regulating valve (31). When the concentration of the refrigeration concentrated solution is detected to be ≤57%, the dilution operation ends, the refrigeration dilute solution pump (34) and the refrigeration evaporator refrigerant circulation pump (33) stop, and the refrigeration cycle can be safely stopped. At this time, the control system gradually increases the amount of refrigerant and the solution circulation volume of the heating cycle to the maximum design value, and the heating load reaches the maximum heating capacity.

7. A composite lithium bromide absorption chiller or hot water unit according to claim 2, characterized in that: When the heating cycle is running and the cooling cycle is stopped, and the cooling cycle needs to be started, first, open the cooling water switching regulating valve (31), open the concentrated cooling solution switching regulating valve (6), the dilute cooling solution switching valve (7) and the refrigerant water switching regulating valve (30), and close the dilute solution bypass valve (4) to start the cooling cycle.

8. A composite lithium bromide absorption chiller or hot water unit according to claim 1 or 5, characterized in that: During the operation of the refrigeration cycle, when it is determined that the concentrated solution in the refrigeration solution heat exchanger (36) has crystallization, the concentrated solution bypass valve (9) is opened to allow the high-temperature concentrated solution to bypass into the bottom of the refrigeration absorber (2) so that the temperature of the dilute solution rises. The high-temperature solution enters the refrigeration solution heat exchanger (36) to heat the concentrated solution and gradually decrystallize. After the crystallization is removed, the concentrated solution bypass valve (9) can be closed.

9. A composite lithium bromide absorption chiller or hot water unit according to claim 8, characterized in that: When the liquid level electrode (35) of the refrigerated dilute solution indicates a low liquid level and the liquid level electrode (10) of the concentrated solution indicates a high liquid level, it can be determined that the concentrated solution of the refrigerated solution heat exchanger (36) has crystallized.

10. A composite lithium bromide absorption chiller or hot water unit according to claim 1, characterized in that: When both the refrigeration and heating cycles are running and need to be stopped simultaneously, to prevent low-temperature crystallization of the concentrated solution circulation system after shutdown, the control system automatically shuts down both the refrigeration and heating cycles into a dilution operation state without the need to operate the valves. When the concentration of the concentrated solution is detected to be ≤57%, the dilution operation ends, and both the refrigeration and heating cycles can be safely stopped.

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