Heat supply system coupled with WNS type gas boiler and lithium bromide absorption heat pump

Abstract

The invention discloses a heat supply system coupled with a WNS type gas-fired boiler and a lithium bromide absorption heat pump. A first partition plate and a second partition plate are vertically arranged in a boiler barrel of a WNS type gas-fired boiler body in the extending direction of a smoke pipe to divide the inner space of the boiler barrel into three independent cavities; the generator, the return water heat exchanger and the evaporator of the lithium bromide absorption type heat pump system are respectively formed, and compared with separated arrangement of a lithium bromide absorption type heat pump and a WNS boiler, the cost and the occupied area are reduced, and the WNS boiler and the lithium bromide absorption type heat pump are integrally arranged; the high-temperature flue gas discharged from the hearth sequentially heats the return water, the lithium bromide solution, the return water and the refrigerant water, so that the temperature of a driving heat source entering the generator is increased, the outlet flue gas temperature is reduced, and the problems that the outlet flue gas temperature of a heat pump cannot be reduced to a very low degree and the overall efficiency is not high due to low flue gas temperature when the heat pump is driven by boiler flue gas discharge are solved; and the energy utilization efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of boilers, relates to the technical field of gas heating and flue gas waste heat recovery, and in particular to a heating system coupling a WNS type gas boiler and a lithium bromide absorption heat pump. Background Art

[0002] Existing natural gas boilers heat the return water of the heat network through the flue gas in the second return flue pipe and the third return flue pipe to provide heat. The flue gas at the boiler outlet is generally 100-200℃. The flue gas can be cooled to a lower temperature by arranging a condensing heat exchanger at the flue gas outlet. However, due to the high return water temperature of the condenser, which is close to the dew point temperature of the water vapor in the flue gas, it is difficult for the water vapor in the flue gas to undergo a phase change (from gas to liquid) to release the latent heat of vaporization. The water vapor in the flue gas does not have enough power to continue condensing, so the latent heat of vaporization cannot be released, and a large amount of latent heat of vaporization in the flue gas cannot be recovered.

[0003] In addition, the existing lithium bromide absorption heat pumps are mostly split when recovering waste heat from natural gas boiler flue gas. The gas boiler and the absorption heat pump are arranged separately. The flue gas leaves the boiler and then enters the absorption heat pump. At this time, the flue gas at the boiler outlet is too low in temperature when used as a generator driving heat source, resulting in a large amount of latent heat in the flue gas that cannot be recovered. The split arrangement increases the cost and floor space of the system, and is poor in economic efficiency. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a heating system coupling a WNS type gas boiler and a lithium bromide absorption heat pump, which is used for full heat utilization of flue gas to improve boiler efficiency, while having low cost, small footprint and greater economy.

[0005] The present invention is achieved through the following technical solutions:

[0006] A heating system coupled with a WNS gas boiler and a lithium bromide absorption heat pump, comprising a WNS gas boiler body, wherein a first partition plate and a second partition plate are respectively arranged vertically in the boiler drum of the WNS gas boiler body along the extension direction of the smoke pipe to divide the internal space of the boiler drum into three independent chambers; the first chamber is located at a side of the boiler drum away from the smoke exhaust pipe, and a furnace, a second return smoke pipe, and a third return smoke pipe are partially located in the first chamber; the second chamber is located at a side of the boiler drum close to the smoke exhaust pipe, and a tail section of the third return smoke pipe is located in the second chamber; the third chamber is located between the other two chambers, and a furnace, a second return smoke pipe, and a third return smoke pipe are partially located in the third chamber;

[0007] The first chamber is filled with lithium bromide solution to form a generator of a lithium bromide absorption heat pump, the second chamber is provided with a liquid distributor for spraying refrigerant to form an evaporator of the lithium bromide absorption heat pump, and the third chamber is connected to a pipeline for adding return water of the heat network to serve as a return water heat exchanger of a WNS type gas boiler;

[0008] The absorber and condenser are both installed on the return water pipeline of the heating network. The hot water at the return water heat exchanger outlet is used for heating the user, and then it is cooled and becomes the return water of the heating network and enters the return water pipeline of the heating network. The return water of the heating network is heated by the absorber and condenser in turn, and then returns to the boiler return water heat exchanger to be heated into hot water to form a cycle;

[0009] The refrigerant channel of the condenser is connected with the generator and the evaporator respectively; the refrigerant steam inlet of the absorber is connected with the steam outlet of the evaporator, and the lithium bromide concentrated solution inlet and the lithium bromide dilute solution outlet of the absorber are connected with the generator through pipelines respectively; the water vapor generated by the generator enters the condenser for condensation and then passes into the liquid distributor in the evaporator, and the water vapor generated by the refrigerant evaporating after absorbing heat enters the absorber.

[0010] Furthermore, an adjusting branch pipe is connected between the second return smoke pipe and the same smoke pipe in the third return smoke pipe in the third chamber, and valves are installed on the adjusting branch pipe and on the second return smoke pipe and the third return smoke pipe connected to the adjusting branch pipe. The conduction and shutdown between the second return smoke pipe and the third return smoke pipe in the third chamber are controlled by the adjusting branch pipe and the valve.

[0011] Furthermore, a solution heat exchanger is arranged on the lithium bromide dilute solution and concentrated solution pipelines connecting the absorber and the generator.

[0012] Furthermore, a solution pump is installed on the lithium bromide concentrated solution pipeline connecting the solution heat exchanger and the generator.

[0013] Furthermore, valves are installed respectively on the lithium bromide concentrated solution pipeline connecting the solution heat exchanger and the generator and on the pipeline connecting the refrigerant outlet of the condenser and the refrigerant inlet of the liquid distributor.

[0014] Furthermore, the cooling water inlet of the absorber is connected to the heat network return water pipeline, the cooling water outlet of the absorber is connected to the cooling water inlet of the condenser, the cooling water outlet of the condenser is connected to the return water heat exchanger inlet, and the return water heat exchanger outlet is connected to the heat network pipeline.

[0015] Furthermore, a water pump is installed on the pipeline connecting the return water pipeline of the heat network and the cooling water inlet of the absorber.

[0016] Furthermore, the second return smoke pipe is a straight pipe, and the third return smoke pipe is an internally threaded pipe.

[0017] The present invention has the following beneficial effects:

[0018] In the drum of the WNS gas boiler body, the first partition and the second partition are respectively arranged vertically along the extension direction of the smoke pipe to divide the internal space of the drum into three independent chambers, which respectively constitute the generator, return water heat exchanger and evaporator of the lithium bromide absorption heat pump system. The generator, return water heat exchanger and evaporator are arranged inside the drum. The internal space of the drum is relatively regular, and the idle space of the drum can be fully utilized, avoiding the need to set up a large installation site for the heat pump system outside the boiler. At the same time, compared with the separate arrangement of the lithium bromide absorption heat pump and the WNS boiler, the cost and floor space are reduced. In addition, the internal arrangement reduces the material cost and installation cost of the pipeline. Because the length of the pipeline is shortened, not only the purchase cost of the pipe is reduced, but also the labor cost and the number of pipe fittings used during the pipeline installation process are reduced.

[0019] The medium temperature inside the drum is relatively high, which is conducive to the operation of the lithium bromide absorption heat pump system. The high-temperature flue gas in the second and third return smoke pipes of the boiler provides a driving heat source for the heat pump, and the evaporator provides a low-temperature cold source for the flue gas. The coupling of the gas boiler and the absorption heat pump reduces the floor space, reduces costs, and improves energy efficiency. The generator inside the drum can better utilize the high-temperature heat source in the drum and improve the generation efficiency of the lithium bromide solution. The return water heat exchanger and evaporator can also have better heat transfer performance because they are close to the heat source in the drum, reducing the investment in additional heating or cooling equipment, thereby improving the economy of the entire system. The flue gas temperature in the generator smoke pipe is relatively high, and the smoke pipe is immersed in the lithium bromide solution to prevent the solution from drying up due to the high temperature.

[0020] The WNS boiler and lithium bromide absorption heat pump are arranged in an integrated manner. The generator is arranged at the rear section of the second return and the front section of the third return. The internal lithium bromide solution is separated from the return water by a partition. The evaporator is arranged at the rear section of the third return. The refrigerant is sprayed onto the surface of the smoke pipe through a horizontal falling film distributor. The refrigerant evaporates after absorbing heat. The high-temperature flue gas coming out of the furnace heats the return water, lithium bromide solution, return water and refrigerant water in turn, which increases the temperature of the driving heat source entering the generator, reduces the outlet flue gas temperature, improves energy utilization efficiency, and solves the problem that if the heat pump is driven by boiler exhaust, the outlet flue gas temperature of the heat pump cannot be reduced to a very low level due to the low flue gas temperature, resulting in low overall efficiency. The refrigerant solution temperature in the evaporator is relatively low. The refrigerant solution is evenly distributed on the surface of the smoke pipe through the distributor to fully absorb the waste heat of the flue gas, avoiding the problem that the existing method cannot fully recover a large amount of latent heat of vaporization in the flue gas through the condenser, and improves the heat exchange efficiency.

[0021] An adjusting branch is set between the second return smoke pipe and the third return smoke pipe. When the load of the boiler changes, part of the second return smoke pipe and the third return smoke pipe are turned on or off through the adjusting branch, and the amount of flue gas passing through the generator 7 is adjusted to adjust the operation of the generator and adjust the working condition of the entire heating system. When the water supply temperature demand of the external heating network changes, the system has flexible adjustment capabilities, so that the system can adapt well to the changes in heat load at different times, ensuring the stable operation of the system under various working conditions.

[0022] The second return smoke pipe is a straight pipe, and the third return smoke pipe is an internally threaded pipe, which improves the heat exchange coefficient of the flue gas in the pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Figure numerals: 1. burner; 2. furnace; 3. backfire chamber; 4. front return smoke chamber; 5. second return smoke duct; 6. third return smoke duct; 7. generator; 8. return water heat exchanger; 9. evaporator; 10. smoke exhaust pipe; 11. liquid distributor; 12-1. first partition; 12-2. second partition; 13. boiler drum; 14. absorber; 15. condenser; 16. solution heat exchanger; 17. solution pump; 18. feed water pump; 19. first valve; 20. second valve; 21. third valve. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0026] See also Figure 1 The present invention provides a heating system coupling a WNS gas boiler and a lithium bromide absorption heat pump, comprising a burner 1, a furnace 2, a re-ignition chamber 3, a front smoke return chamber 4, a second return smoke pipe 5, a third return smoke pipe 6, a generator 7, a return water heat exchanger 8, an evaporator 9, a smoke exhaust pipe 10, a liquid distributor 11, a first baffle 12-1, a second baffle 12-2, a drum 13, an absorber 14, a condenser 15, a solution heat exchanger 16, a solution pump 17, a feed water pump 18, a first valve 19, a second valve 20, and a third valve 21.

[0027] In the drum 13 of the WNS gas boiler, a first partition 12-1 and a second partition 12-2 are respectively arranged along the extension direction of the smoke pipe. The vertically arranged first partition 12-1 and second partition 12-2 divide the internal space of the drum 13 into three independent chambers. The first partition 12-1 is arranged on the side of the drum 13 away from the boiler exhaust pipe 10, and a first chamber is formed in the drum 13 away from the exhaust pipe 10. The furnace 2, the second return smoke pipe 5, and the front section of the third return smoke pipe 6 are all located in the first chamber. The second partition 12-2 is arranged on the side of the drum 13 close to the boiler exhaust pipe 10, and a second chamber close to the exhaust pipe 10 is formed in the drum 13. The tail section of the third return smoke pipe 6 is located in the second chamber. A third chamber is formed between the first partition 12-1 and the second partition 12-2 in the drum 13, and the middle part of the furnace 2, the second return smoke pipe 5, and the third return smoke pipe 6 is located in the third chamber.

[0028] The first chamber is filled with lithium bromide solution to form a generator 7 of a lithium bromide absorption heat pump, a liquid distributor 11 for spraying refrigerant is arranged in the second chamber to form an evaporator 9 of the lithium bromide absorption heat pump, and the third chamber is connected to a pipeline for adding return water from the heating network to heat the return water from the heating network, serving as a return water heat exchanger 8 of a WNS type gas boiler; the generator 7, the return water heat exchanger 8 and the evaporator 9 are arranged inside the boiler drum 13 and separated by a first partition 12-1 and a second partition 12-2.

[0029] An absorber 14 and a condenser 15 are arranged above the boiler drum 13. Both the absorber 14 and the condenser 15 are installed on the return water pipeline of the heat network. The refrigerant inlet of the condenser 15 is connected to the steam outlet of the generator 7, the refrigerant outlet of the condenser 15 is connected to the refrigerant inlet of the liquid distributor 11 arranged in the evaporator 9, the cooling water inlet of the condenser 15 is connected to the return water pipeline of the heat network, the cooling water outlet of the condenser 15 is connected to the water inlet of the return water heat exchanger 8, and the water outlet of the return water heat exchanger 8 is connected to the heat network pipeline to provide high-calorie hot water for users.

[0030] The refrigerant vapor inlet of the absorber 14 is connected to the vapor outlet of the evaporator 9, and the lithium bromide concentrated solution inlet and the lithium bromide dilute solution outlet of the absorber 14 are connected to the generator 7 through pipelines respectively; the cooling water inlet of the absorber 14 is connected to the heat network return pipeline, and the cooling water outlet of the absorber 14 is connected to the cooling water inlet of the condenser 15. The water vapor generated by the generator 7 directly enters the condenser 15 through the steam outlet above the boiler drum 13, and the water vapor generated by the evaporator 9 directly enters the absorber 14 through the steam outlet above the boiler drum 13.

[0031] The solution heat exchanger 16 is arranged on the lithium bromide dilute solution and concentrated solution pipelines connecting the absorber 14 and the generator 7, and is used to realize the heat exchange between the lithium bromide dilute solution and the concentrated solution entering and leaving the drum, so as to increase the temperature of the lithium bromide dilute solution entering the drum and improve the overall thermal efficiency of the boiler. A solution pump 17 is installed on the lithium bromide concentrated solution pipeline connecting the solution heat exchanger 16 and the generator 7 to provide a driving force for the lithium bromide dilute solution to enter the generator 7; valves are respectively installed on the lithium bromide concentrated solution pipeline connecting the solution heat exchanger 16 and the generator 7 and on the pipeline connecting the refrigerant outlet of the condenser 15 and the refrigerant inlet of the liquid distributor 11.

[0032] The generator 7 is filled with lithium bromide solution, the furnace 2, the second return smoke pipe 5, and the front section of the third return smoke pipe 6 are all immersed in the lithium bromide solution, and the lithium bromide solution generates water vapor after heating. The water vapor generated in the generator 7 enters the condenser 15 through the steam outlet above the boiler for condensation; the return water heat exchanger 8 is filled with heat network return water, and the furnace 2, the second return smoke pipe 5, and the middle section of the third return smoke pipe 6 are all immersed in the heat network return water; the upper part of the evaporator 9 is arranged with a horizontal falling film liquid distributor 11 to spray the refrigerant solution onto the surface of the third return smoke pipe 6. The refrigerant solution at the inlet of the evaporator 9 is evenly distributed to the smoke pipe surface through the horizontal falling film liquid distributor 11, and evaporated after being heated. The refrigerant vapor at the outlet of the evaporator 9 is absorbed by the lithium bromide concentrated solution in the absorber 14.

[0033] like Figure 1 As shown, in order to adapt to the change of water supply temperature of the heating network, when the load of the boiler changes, the load of the heat pump can be adjusted by opening or closing the valve, so that the whole system has the ability of flexible adjustment. An adjusting branch is connected between the same smoke pipe in part of the second return smoke pipe 5 and the third return smoke pipe 6 in the third chamber, and the same smoke pipe in the second return smoke pipe 5 and the third return smoke pipe 6 is connected through the adjusting branch. The first valve 19 is installed on the adjusting branch. Correspondingly, a second valve 20 is installed on the second return smoke pipe 5 connected to the adjusting branch, and a third valve 21 is installed on the third return smoke pipe 6 connected to the adjusting branch. Along the direction of flue gas flow, the second valve 20 and the third valve 21 are located after the adjusting branch. When the load of the heating system increases, the second valve 20 and the third valve 21 are opened, and the first valve 19 is closed to close the adjusting branch, so that the flue gas passes through the generator, and the heat load of the generator 7 is large; the lithium bromide absorption heat pump meets the heat output demand under high load. When the load of the heating system decreases, the first valve 19 is opened, and the second valve 20 and the third valve 21 are closed, so that the regulating branch pipe partially connects the second return smoke pipe 5 and the third return smoke pipe 6, thereby reducing the amount of smoke entering the generator 7. The heat load of the generator 7 is small, reducing the heat output of the lithium bromide absorption heat pump, and meeting the low-load operation requirements of the system.

[0034] The high-temperature flue gas coming out of the furnace passes through the generator 7, the return water heat exchanger 8, and the evaporator 9 in the three return paths of the furnace 2, the second return flue pipe 5, and the third return flue pipe 6. The high-temperature flue gas coming out of the furnace first enters the generator. At this time, the flue gas temperature is the highest, which can provide enough heat for the generator to drive the generation process of the lithium bromide solution. Then, the flue gas with a lowered temperature enters the return water heat exchanger to effectively heat the return water. The flue gas in the third return flue pipe enters the evaporator. Although the flue gas temperature has been reduced at this time, it can still provide heat for the evaporator to achieve multiple heat exchanges. After multiple heat recovery, the heat of the flue gas is fully utilized, thereby achieving full absorption of latent heat.

[0035] A water pump 18 is installed on the connecting pipe between the heat network return water pipeline and the cooling water inlet of the absorber 14. The hot water at the boiler outlet is cooled after being supplied to the user for heating and becomes the heat network return water. The heat network return water is first pressurized by the water pump 18 and then enters the absorber 14 and the condenser 15 in turn to be heated, and finally returns to the boiler to be heated into hot water to form a cycle.

[0036] In order to further improve the heat exchange efficiency, the second return smoke pipe is a straight pipe, and the third return smoke pipe is an internally threaded pipe.

[0037] Table 1 System operation temperature table

[0038] variable unit Numeric Furnace outlet flue gas temperature ℃ 946 Generator inlet flue gas temperature ℃ 450 Generator outlet flue gas temperature ℃ 150 Evaporator inlet flue gas temperature ℃ 60 Evaporator outlet flue gas temperature ℃ 34.5 Absorber inlet return water temperature ℃ 50 Absorber outlet return water temperature ℃ 56.5 Condenser inlet return water temperature ℃ 58.5 Condenser outlet return water temperature ℃ 63.6 Generator inlet dilute solution temperature ℃ 89.7 Generator outlet concentrated solution temperature ℃ 123.1 Generator outlet steam temperature ℃ 123.1 Absorber outlet dilute solution temperature ℃ 54.3 Condenser inlet water vapor temperature ℃ 123.1 Condenser outlet liquid water temperature ℃ 69.1 Evaporator inlet liquid water temperature ℃ 21 Evaporator outlet water vapor temperature ℃ 22.2 Concentrated solution temperature at the inlet of solution heat exchanger ℃ 123.1 Dilute solution temperature at the inlet of solution heat exchanger ℃ 54.3 Concentrated solution temperature at outlet of solution heat exchanger ℃ 66.5 Dilute solution temperature at solution heat exchanger outlet ℃ 89.7

[0039] As shown in Table 1, after testing the heating system of the coupling WNS gas boiler and lithium bromide absorption heat pump of the present invention, the flue gas temperature at the outlet of the system furnace 2 is 946°C, the flue gas temperature at the inlet of the generator 7 is 450°C, the flue gas temperature at the outlet of the generator 7 is 150°C, the flue gas temperature at the inlet of the evaporator 9 is 60°C, the flue gas temperature at the outlet of the exhaust pipe 10 is about 30°C, and 80% of the water vapor in the flue gas is condensed. The temperature of the return water entering the absorber 14 is 50°C, the temperature of the return water leaving the absorber 14 and entering the condenser 15 is 56.5°C, and the temperature of the return water leaving the condenser 15 and entering the boiler return water heater 8 is 63.6°C.

[0040] At the same time, the traditional split-type gas boiler and lithium bromide absorption heat pump heating system were tested. When no other driving heat source was provided in the generator, the flue gas temperature at the gas boiler outlet was 160°C, that is, the flue gas temperature at the generator inlet was 160°C, the flue gas temperature at the generator outlet was 110°C, the flue gas temperature at the evaporator inlet was 60°C, and the evaporator outlet temperature was 56°C. Most of the water vapor in the flue gas cannot be condensed, the exhaust gas residual temperature reaches 60°C, and a large amount of latent heat is wasted.

[0041] Through the above comparison, it can be found that, by using the heating system of the present invention coupling the WNS type gas boiler and the lithium bromide absorption heat pump, the waste heat in the flue gas is fully absorbed, thereby improving the heat exchange efficiency.

Claims

1. A heating system coupling a WNS gas boiler and a lithium bromide absorption heat pump, characterized in that: The invention comprises a WNS type gas boiler body, wherein a first partition plate (12-1) and a second partition plate (12-2) are respectively arranged vertically in a boiler drum (13) along the extension direction of the smoke pipe to divide the internal space of the boiler drum (13) into three independent chambers; the first chamber is located at a side of the boiler drum (13) away from the smoke exhaust pipe (10), and the furnace (2), the second return smoke pipe (5), and the third return smoke pipe (6) are partially located in the first chamber; the second chamber is located at a side of the boiler drum (13) close to the smoke exhaust pipe (10), and the tail section of the third return smoke pipe (6) is located in the second chamber; the third chamber is located between the other two chambers, and the furnace (2), the second return smoke pipe (5), and the third return smoke pipe (6) are partially located in the third chamber; A lithium bromide solution is injected into the first chamber to form a generator (7) of a lithium bromide absorption heat pump, a liquid distributor (11) for spraying refrigerant is arranged in the second chamber to form an evaporator (9) of the lithium bromide absorption heat pump, and the third chamber is connected to a pipeline for adding return water to the heat network to serve as a return water heat exchanger (8) of a WNS type gas boiler; The absorber (14) and the condenser (15) are both installed on the return water pipeline of the heating network. The hot water at the outlet of the return water heat exchanger (8) is used for heating the user and then cooled to become the return water of the heating network and enter the return water pipeline of the heating network. The return water of the heating network is heated in turn by the absorber (14) and the condenser (15) and then returns to the boiler return water heat exchanger (8) to be heated into hot water for supply, forming a cycle. The refrigerant channel of the condenser (15) is respectively connected to the generator (7) and the evaporator (9); the refrigerant steam inlet of the absorber (14) is connected to the steam outlet of the evaporator (9); the lithium bromide concentrated solution inlet and the lithium bromide dilute solution outlet of the absorber (14) are respectively connected to the generator (7) through pipelines; the water vapor generated by the generator (7) enters the condenser (15) for condensation and then enters the liquid distributor (11) in the evaporator (9); the water vapor generated by the refrigerant evaporating after absorbing heat enters the absorber (14).

2. The heating system of coupling a WNS type gas boiler and a lithium bromide absorption heat pump according to claim 1 is characterized in that: An adjusting branch pipe is connected between the second return smoke pipe (5) and the third return smoke pipe (6) in the third chamber, and valves are installed on the adjusting branch pipe and on the second return smoke pipe (5) and the third return smoke pipe (6) connected to the adjusting branch pipe. The connection and disconnection between the second return smoke pipe (5) and the third return smoke pipe (6) in the third chamber are controlled by the adjusting branch pipe and the valve.

3. The heating system of coupling a WNS type gas boiler and a lithium bromide absorption heat pump according to claim 2 is characterized in that: A solution heat exchanger (16) is provided on the lithium bromide dilute solution and concentrated solution pipelines connecting the absorber (14) and the generator (7).

4. The heating system of coupling a WNS type gas boiler and a lithium bromide absorption heat pump according to claim 3 is characterized in that: A solution pump (17) is installed on the lithium bromide concentrated solution pipeline connecting the solution heat exchanger (16) and the generator (7).

5. The heating system of coupling a WNS type gas boiler and a lithium bromide absorption heat pump according to claim 4 is characterized in that: Valves are respectively installed on the lithium bromide concentrated solution pipeline connecting the solution heat exchanger (16) and the generator (7) and on the pipeline connecting the refrigerant outlet of the condenser (15) and the refrigerant inlet of the liquid distributor (11).

6. The heating system of coupling a WNS type gas boiler and a lithium bromide absorption heat pump according to any one of claims 1 to 5, characterized in that: The cooling water inlet of the absorber (14) is connected to the return water pipeline of the heat network, the cooling water outlet of the absorber (14) is connected to the cooling water inlet of the condenser (15), the cooling water outlet of the condenser (15) is connected to the water inlet of the return water heat exchanger (8), and the water outlet of the return water heat exchanger (8) is connected to the heat network pipeline.

7. The heating system of coupling a WNS type gas boiler and a lithium bromide absorption heat pump according to claim 6 is characterized in that: A water pump (18) is installed on a pipeline connecting a heat network return water pipeline and a cooling water inlet of an absorber (14).

8. The heating system of coupling a WNS type gas boiler and a lithium bromide absorption heat pump according to claim 6, characterized in that: The second return smoke pipe (5) is a straight pipe, and the third return smoke pipe (6) is an internally threaded pipe.

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