CN215295426U

CN215295426U - Smoke hot water type lithium bromide absorption cold-water heat pump unit

Info

Publication number: CN215295426U
Application number: CN202121673070.5U
Authority: CN
Inventors: 张长江; 陈荣霞
Original assignee: Shuangliang Eco Energy Systems Co Ltd
Current assignee: Shuangliang Eco Energy Systems Co Ltd
Priority date: 2021-07-22
Filing date: 2021-07-22
Publication date: 2021-12-24
Anticipated expiration: 2031-07-22

Abstract

The utility model relates to a flue gas hot water type lithium bromide absorption formula cold water heat pump unit, be provided with the solution of taking the diverter valve, steam and water route closed tube, plate heat exchanger's low temperature side hot water advances, the outlet pipe advances with medium temperature water, the outlet pipe hookup, thereby make the unit both can refrigerate according to the theory of operation of lithium bromide absorption formula refrigerator, also can supply heat according to the theory of operation of first type lithium bromide absorption heat pump unit and the combination heat supply mode of plate heat exchanger heat transfer, possess the function of retrieving waste heat supply, can satisfy refrigeration in summer, the application demand that winter needs first type lithium bromide absorption heat pump heat supply, be favorable to reducing the equipment configuration number of stations of air conditioner energy, reduce energy station equipment investment cost.

Description

Smoke hot water type lithium bromide absorption cold-water heat pump unit

Technical Field

The utility model relates to an air conditioning equipment technical field, concretely relates to flue gas hot water type lithium bromide absorption formula cold water heat pump unit.

Background

A conventional flue gas hot water type lithium bromide absorption cold and hot water unit is shown in fig. 1, and the unit is composed of an evaporator 3, an absorber 1, a flue gas type high pressure generator 17, a steam generator 26, a hot water generator 28, a condenser 31, a low temperature heat exchanger 12, a high temperature heat exchanger 15, a flue gas heat exchanger 18, a plate heat exchanger 33, a solution pump 4, a solution lift pump 7, a refrigerant pump 2, a control system (not shown in the figure), and pipelines and valves for connecting the components. The steam generator 26, the hot water generator 28 and the condenser 31 are arranged in the same low-heat-value condenser cylinder 32, the steam generator 26 and the hot water generator 28 are in a left-right arrangement structure, and a low-heat-value solution separation plate 27 which is vertically arranged is arranged in the low-heat-value condenser cylinder 32; a low-temperature side hot water inlet pipe, namely a plate heat exchange water inlet pipe 48, of the plate heat exchanger 33 is connected with an evaporator water inlet pipe 47 of the unit, a low-temperature side hot water outlet pipe, namely a plate heat exchange water outlet pipe 40, of the plate heat exchanger 33 is connected with an evaporator water outlet pipe 45 of the unit, and the hot water supply flows of the plate heat exchanger 33 and the evaporator 4 are parallel flows when the unit supplies heat; the cooling water flow of the absorber 1 and the condenser 31 is a parallel flow when the unit operates in refrigeration; a heating solution switching valve 53 is installed on a connection pipe between the high refrigerant vapor outlet pipe 16 and the evaporation absorber cylinder 46, and a heating vapor switching valve 54 is installed on a connection pipe between the high refrigerant vapor outlet pipe 24 and the evaporation absorber cylinder 46. The unit is mainly applied to a distributed energy system, and is driven by high-temperature flue gas and high-temperature cylinder sleeve water (heat source hot water) discharged by a gas internal combustion engine generator set to carry out refrigeration and heat supply operation, so that cold water and hot water for comfortable air conditioning or process cooling (or heating) are provided for the outside. When the unit is used for heating, heat exchange and heat supply can be carried out only by using the working principle of the heat exchanger, and the unit does not have the functions of recovering waste heat and supplying heat according to the working principle of the heat pump and is not suitable for application places needing refrigeration in summer and heat supply of the heat pump in winter.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects and provide a flue gas hot water type lithium bromide absorption cold water heat pump unit, the low-temperature side hot water inlet pipe and the low-temperature side hot water outlet pipe of the plate heat exchanger are connected with the medium-temperature water inlet pipe and the medium-temperature water outlet pipe by additionally arranging a solution, steam and water path communicating pipe with a switching valve (or a stop valve) on the basis of the original flue gas hot water type lithium bromide absorption cold and hot water unit, therefore, the unit can not only refrigerate according to the working principle of the lithium bromide absorption refrigerator, but also supply heat according to the working principle of the first type of lithium bromide absorption heat pump unit and a combined heat supply mode of heat exchange of the plate heat exchanger, has the function of recovering waste heat and supplying heat, can meet the application requirements of refrigerating in summer and supplying heat by the first type of lithium bromide absorption heat pump in winter, is beneficial to reducing the equipment configuration number of the air conditioning energy station, and reduces the equipment investment cost of the energy station.

The purpose of the utility model is realized like this:

a flue gas hot water type lithium bromide absorption cold water heat pump unit comprises an evaporator, an absorber, a flue gas type high-pressure generator, a hot water generator, a steam generator, a condenser, a low-temperature heat exchanger, a high-temperature heat exchanger, a flue gas heat exchanger, a plate heat exchanger, a solution pump, a solution lift pump and a refrigerant pump. The hot water generator, the steam generator and the condenser are arranged in the same low-temperature condenser cylinder, and the hot water generator and the steam generator are of a left-right arrangement structure. A solution stop valve is arranged on a liquid outlet pipe of the solution lift pump, a first solution switching valve is arranged on a liquid outlet pipe of the flue gas heat exchanger, a dilute solution communicating pipe with a second solution switching valve is connected between the liquid outlet pipe of the flue gas heat exchanger and the liquid outlet pipe of the solution lift pump, and a concentrated solution communicating pipe with a third solution switching valve is connected between a solution inlet pipe of the steam generator and a liquid inlet pipe of the absorber. A condenser steam inlet pipe with a steam stop valve is connected between the high refrigerant steam outlet pipe and the low refrigerant condenser cylinder. The water inlet pipe of the condenser is provided with a first switching valve of the water inlet pipe, a condenser water inlet communicating pipe with a second switching valve of the water inlet pipe is connected between the water outlet pipe of the absorber and the water inlet pipe of the condenser, and an absorber water outlet straight-through pipe with a first switching valve of the water outlet pipe is connected between the water outlet pipe of the absorber and the medium temperature water outlet pipe. The plate heat exchange water inlet pipe on the low-temperature hot water side of the plate heat exchanger is connected with the medium-temperature water inlet pipe, and the plate heat exchange water outlet pipe on the low-temperature hot water side of the plate heat exchanger is connected with the medium-temperature water outlet pipe. When the unit operates in a refrigerating mode, the solution circulation flow is a composite type series flow, and the cooling water flow of the absorber and the condenser is a parallel flow; when the unit is in heating operation, the hot water flow of the plate heat exchanger, the absorber and the condenser is a parallel flow.

Preferably, the hot water generator and the steam generator are arranged vertically, and when the unit operates in a refrigerating mode, the solution circulation flow is a composite series flow.

Preferably, the hot water generator and the steam generator are arranged up and down, and when the unit operates in a refrigerating mode, the solution circulation flow is an inverted series flow.

Preferably, when the unit is operated in a refrigerating mode, the cooling water flow of the absorber and the condenser is a series flow.

Preferably, when the unit is operated for supplying heat, the hot water flow of the plate heat exchanger, the absorber and the condenser is a series flow.

The utility model has the advantages that:

the utility model discloses the unit is provided with the solution of taking diverter valve (or stop valve), steam and water route closed tube, plate heat exchanger's low temperature side hot water advances, the outlet pipe advances with medium temperature water, the outlet pipe hookup, thereby make the unit both can refrigerate according to the theory of operation of lithium bromide absorption refrigerator, also can supply heat according to the theory of operation of first type lithium bromide absorption heat pump unit and the combination heat supply mode of plate heat exchanger heat transfer, possess the function of retrieving waste heat supply, can satisfy refrigeration in summer, the application demand that needs first type lithium bromide absorption heat pump heat supply winter, be favorable to reducing the equipment configuration number at air conditioner energy station, reduce energy station equipment investment cost.

Drawings

Fig. 1 is a schematic structural diagram of a conventional flue gas hot water type lithium bromide absorption cold and hot water unit.

Fig. 2 is a schematic structural view of a flue gas hot water type lithium bromide absorption water heating pump unit according to the first embodiment of the present invention.

Fig. 3 is a schematic structural view of a flue gas hot water type lithium bromide absorption water heating pump unit according to the second embodiment of the present invention.

Fig. 4 is a schematic structural view of a flue gas hot water type lithium bromide absorption water heat pump unit according to a third embodiment of the present invention.

Fig. 5 is a schematic structural view of a flue gas hot water type lithium bromide absorption water heating pump unit according to a fourth embodiment of the present invention.

Fig. 6 is a schematic structural view of a flue gas hot water type lithium bromide absorption water heating pump unit according to a fifth embodiment of the present invention.

Wherein: 1-absorber, 2-refrigerant pump, 3-evaporator, 4-solution pump, 5-absorber liquid inlet pipe, 6-steam generator liquid outlet pipe, 7-solution lift pump, 8-solution lift pump liquid outlet pipe, 9-solution stop valve, 10-first solution switching valve, 11-second solution switching valve, 12-low temperature heat exchanger, 13-flue gas heat exchanger liquid outlet pipe, 14-dilute solution communicating pipe, 15-high temperature heat exchanger, 16-high liquid outlet pipe, 17-flue gas type high pressure generator, 18-flue gas heat exchanger, 19-flue gas outlet pipe, 20-flue gas inlet pipe, 21-third solution switching valve, 22-concentrated solution communicating pipe, 23-hot water generator liquid outlet pipe, 24-high refrigerant steam outlet pipe, 25-steam generator liquid inlet pipe, 26-steam generator, 27-low heat generation solution partition board, 28-hot water generator, 29-condenser steam inlet pipe, 30-steam stop valve, 31-condenser, 32-low heat generation condenser cylinder, 33-plate heat exchanger, 34-heat source hot water inlet pipe, 35-heat source hot water outlet pipe, 36-condenser water outlet pipe, 37-absorber water outlet pipe, 38-water inlet pipe second switching valve, 39-condenser water inlet communicating pipe, 40-plate heat exchange water outlet pipe, 41-hot water pipe first stop valve, 42-medium temperature water outlet pipe, 43-absorber outlet water straight-through pipe, 44-water outlet pipe first switching valve, 45-evaporator water outlet pipe, 46-evaporation absorber cylinder, 47-evaporator water inlet pipe, 28-hot water generator, 29-condenser steam inlet pipe, 30-steam stop valve, 31-condenser, 32-low heat generation condenser cylinder, 33-plate heat exchanger, 34-heat source hot water inlet pipe, 35-heat source hot water outlet pipe, 36-condenser water outlet pipe, 37-absorber outlet pipe, 38-absorber outlet pipe first switching valve, 44-evaporator water inlet pipe first switching valve, 45-evaporator water outlet pipe, 46-evaporator water outlet pipe, 47-evaporator water outlet pipe, 45-evaporator water outlet pipe, 40-evaporator water outlet pipe, and 40-heat exchanger water outlet pipe, and 40-absorber water pipe, 6-absorber water pipe, and 40-absorber water pipe, 48-plate heat exchange water inlet pipe, 49-hot water pipe second stop valve, 50-condenser inlet pipe, 51-inlet pipe first switching valve, 52-medium temperature water inlet pipe, 53-heat supply solution switching valve, 54-heat supply steam switching valve, 55-low concentration solution inlet pipe and 56-outlet pipe second switching valve.

Detailed Description

The first embodiment is shown in fig. 2, and the utility model relates to a flue gas hot water type lithium bromide absorption cold water heat pump unit, which comprises an evaporator 3, an absorber 1, a flue gas type high pressure generator 17, a hot water generator 28, a steam generator 26, a condenser 31, a low temperature heat exchanger 12, a high temperature heat exchanger 15, a flue gas heat exchanger 18, a plate heat exchanger 33, a solution pump 4, a solution lift pump 7, a refrigerant pump 2, a control system (not shown in the figure) and pipelines and valves for connecting all parts. The hot water generator 28, the steam generator 26 and the condenser 31 are arranged in the same low-temperature condenser cylinder 32, the low-temperature condenser cylinder 32 is internally provided with a low-temperature solution separation plate 27 which is vertically arranged, and the hot water generator 28 and the steam generator 26 adopt a left-right arrangement structure. The solution lift pump 7 is arranged on a solution outlet pipe of a hot water generator 28, namely a hot water generator liquid outlet pipe 23, a solution stop valve 9 is arranged on a solution outlet pipe of the solution lift pump 7, namely a solution lift pump liquid outlet pipe 8, a first solution switching valve 10 is arranged on a solution outlet pipe of a flue gas heat exchanger 18, namely a flue gas heat exchanger liquid outlet pipe 13, a dilute solution communicating pipe 14 with a second solution switching valve 11 is connected between the flue gas heat exchanger liquid outlet pipe 13 and the solution lift pump liquid outlet pipe 8, and a concentrated solution communicating pipe 22 with a third solution switching valve 21 is connected between a solution inlet pipe of a steam generator 26, namely a steam generator liquid inlet pipe 25, and a concentrated solution inlet pipe of an absorber 1, namely an absorber liquid inlet pipe 5; a condenser steam inlet pipe 29 with a steam stop valve 30 is connected between a refrigerant steam outlet pipe-high refrigerant steam outlet pipe 24 and a low refrigerant condenser cylinder 32 of the smoke type high pressure generator 17; a condenser water inlet pipe 50 of the condenser 31 is connected with a medium temperature water inlet pipe 52 of the unit, a first switching valve 51 of the water inlet pipe is arranged on the condenser water inlet pipe 50, a condenser water inlet communicating pipe 39 with a water inlet pipe second switching valve 38 is connected between an absorber water outlet pipe 37 of the absorber 1 and the condenser water inlet pipe 50, and an absorber water outlet straight-through pipe 43 with a water outlet pipe first switching valve 44 is connected between the absorber water outlet pipe 37 and a medium temperature water outlet pipe 42 of the unit. A hot water inlet pipe at the low-temperature hot water side of the plate heat exchanger 33, namely a plate heat exchange water inlet pipe 48 is connected with a medium-temperature water inlet pipe 52, and a hot water pipe second stop valve 49 is arranged on the plate heat exchange water inlet pipe 48; a hot water outlet pipe at the low-temperature hot water side of the plate heat exchanger 33, namely a plate heat exchange water outlet pipe 40, is connected to a medium-temperature water outlet pipe 42, and a hot water pipe first stop valve 41 is arranged on the plate heat exchange water outlet pipe 40.

When the unit operates in a refrigerating mode, the solution stop valve 9, the first solution switching valve 10, the first water inlet pipe switching valve 51 and the first water outlet pipe switching valve 44 are opened, the second solution switching valve 11, the third solution switching valve 21, the steam stop valve 30, the second water inlet pipe switching valve 38, the first hot water pipe stop valve 41 and the second hot water pipe stop valve 49 are closed, and the plate heat exchanger 33 does not work. The solution circulation flow of the unit is a composite series flow, and the solution circulation flow path is as follows: absorber 1 → solution pump 4 → low temperature heat exchanger 12 → flue gas heat exchanger 18 → hot water generator 28 → solution lift pump 7 → high temperature heat exchanger 15 → flue gas type high pressure generator 17 → high temperature heat exchanger 15 → steam generator 26 → low temperature heat exchanger 12 → absorber 1. The medium-temperature water inlet pipe 52 and the medium-temperature water outlet pipe 42 are used as cooling water inlet and outlet pipes, and the cooling water flow of the absorber 1 and the condenser 31 is a parallel flow; the water inlet pipe 47 of the evaporator and the water outlet pipe 45 of the evaporator of the unit are used as cold water inlet and outlet pipes.

When the unit supplies heat, the solution stop valve 9, the first solution switching valve 10, the first switching valve 51 of the water inlet pipe and the first switching valve 44 of the water outlet pipe are closed, the second solution switching valve 11, the third solution switching valve 21, the steam stop valve 30, the second switching valve 38 of the water inlet pipe, the first pipe stop valve 41 of the hot water pipe and the second stop valve 49 of the hot water pipe are opened, the evaporator 3, the absorber 1, the flue gas type high-pressure generator 17, the condenser 31, the high-temperature heat exchanger 15, the flue gas heat exchanger 18, the solution pump 4, the refrigerant pump 2 and the pipelines and valves connecting the components form a flue gas single-effect type first-class lithium bromide heat pump heat supply system, the solution lift pump 8 does not operate, the hot water generator 28 and the steam generator 26 do not operate, the low-temperature heat exchanger 12 is only used as a dilute solution circulation channel, and the solution circulation flow path is: absorber 1 → solution pump 4 → low temperature heat exchanger 12 → flue gas heat exchanger 18 → high temperature heat exchanger 15 → flue gas type high pressure generator 17 → high temperature heat exchanger 15 → absorber 1. The hot water flow of the plate heat exchanger 33, the absorber 1 and the condenser 33 is a parallel flow, the medium temperature water inlet pipe 52 and the medium temperature water outlet pipe 42 are used as a hot water inlet pipe and a hot water outlet pipe, and the evaporator water inlet pipe 47 and the evaporator water outlet pipe 45 are used as a residual hot water inlet pipe and a residual hot water outlet pipe.

Second embodiment referring to fig. 3, the hot water generator 28 and the steam generator 26 are arranged in an up-down configuration, and a low-boiling-solution partition plate 27 is provided in a horizontal arrangement at a lower portion of the hot water generator 28. The rest of the structure is the same as that of the first embodiment.

Third embodiment referring to fig. 4, the hot water generator 28 and the steam generator 26 are arranged up and down, without a low-concentration solution partition plate, the solution lift pump 7 is disposed on the solution outlet pipe of the steam generator 26, i.e., the steam generator outlet pipe 6, the high-temperature side solution outlet pipe of the high-temperature heat exchanger 15 is used as the concentrated solution inlet pipe of the low-temperature heat exchanger 12, i.e., the low-concentration solution inlet pipe 55 is connected to the low-temperature heat exchanger 12, and no concentrated solution communicating pipe and no third solution switching valve are provided. The rest of the structure is the same as that of the first embodiment. When the unit is operated in a refrigerating mode, the solution circulation flow is an inverted series flow, the solution from the hot water generator 28 directly enters the steam generator 26, and the solution circulation flow path is as follows: absorber 1 → solution pump 4 → low temperature heat exchanger 12 → flue gas heat exchanger 18 → hot water generator 28 → steam generator 26 → solution lift pump 7 → high temperature heat exchanger 15 → flue gas type high pressure generator 17 → high temperature heat exchanger 15 → low temperature heat exchanger 12 → absorber 1. When the unit supplies heat, the solution circulation flow path is as follows: absorber 1 → solution pump 4 → low temperature heat exchanger 12 → flue gas heat exchanger 18 → high temperature heat exchanger 15 → flue gas type high pressure generator 17 → high temperature heat exchanger 15 → low temperature heat exchanger 12 → absorber 1.

Fourth embodiment referring to fig. 5, the condenser inlet pipe 50 is connected to the absorber outlet pipe 37 without a first switching valve for the inlet pipe, a condenser inlet water communication pipe and a second switching valve for the inlet pipe thereof, and without an absorber outlet water straight pipe and a first switching valve for the outlet pipe thereof. The rest of the structure is the same as that of the first embodiment. When the unit is operated in a refrigerating mode, the cooling water flow of the absorber 1 and the condenser 31 adopts a series flow.

Fifth embodiment referring to fig. 6, an outlet pipe second switching valve 56 is provided on the condenser outlet pipe 36 of the condenser 31, and the plate heat exchange water inlet pipe 48 is connected to the condenser outlet pipe 36. The rest of the structure is the same as that of the first embodiment. When the unit operates in a refrigerating mode, the second switching valve 56 of the water outlet pipe is opened; when the unit is in heating operation, the second switching valve 56 of the water outlet pipe is closed, and the hot water flow of the plate heat exchanger 33, the absorber 1 and the condenser 33 is a series flow.

In addition to the above embodiments, the present invention also includes other embodiments, and all technical solutions formed by equivalent transformation or equivalent replacement should fall within the protection scope of the claims of the present invention.

Claims

1. The utility model provides a flue gas hot water type lithium bromide absorption formula cold water heat pump unit, includes evaporimeter (3), absorber (1), flue gas type high pressure generator (17), hot water generator (28), steam generator (26), condenser (31), low temperature heat exchanger (12), high temperature heat exchanger (15), flue gas heat exchanger (18), plate heat exchanger (33), solution pump (4), solution elevator pump (7) and refrigerant pump (2), hot water generator (28), steam generator (26) and condenser (31) set up in same low condenser barrel (32), its characterized in that:

a solution stop valve (9) is arranged on a solution outlet pipe of the solution lift pump (7), namely a solution lift pump liquid outlet pipe (8), a first solution switching valve (10) is arranged on a solution outlet pipe of the flue gas heat exchanger (18), namely a flue gas heat exchanger liquid outlet pipe (13), and a dilute solution communicating pipe (14) with a second solution switching valve (11) is connected between the flue gas heat exchanger liquid outlet pipe (13) and the solution lift pump liquid outlet pipe (8);

a condenser steam inlet pipe (29) with a steam stop valve (30) is connected between a refrigerant steam outlet pipe, namely a high-heating-agent steam outlet pipe (24), of the smoke high-pressure generator (17) and a low-heating-agent condenser cylinder (32);

a hot water outlet pipe at the low-temperature hot water side of the plate heat exchanger (33), namely a plate heat exchange water outlet pipe (40), is connected to a medium-temperature water outlet pipe (42), and a hot water pipe first stop valve (41) is arranged on the plate heat exchange water outlet pipe (40).

2. The flue gas hot water type lithium bromide absorption cold water heat pump unit according to claim 1, characterized in that: the solution lift pump (7) is arranged on a solution outlet pipe of the hot water generator (28), namely a hot water generator liquid outlet pipe (23), a concentrated solution communicating pipe (22) with a third solution switching valve (21) is connected between a solution inlet pipe of a steam generator (26), namely a steam generator liquid inlet pipe (25), and a concentrated solution inlet pipe of the absorber (1), namely an absorber liquid inlet pipe (5), and a solution circulation flow during refrigerating operation of the unit is a composite series flow.

3. The flue gas hot water type lithium bromide absorption cold water heat pump unit according to claim 1, characterized in that: the hot water generator (28) and the steam generator (26) adopt an up-and-down arrangement structure, the solution lift pump (7) is arranged on a solution outlet pipe of the steam generator (26), namely a steam generator liquid outlet pipe (6), and a high-temperature side solution outlet pipe of the high-temperature heat exchanger (15) is used as a concentrated solution inlet pipe of the low-temperature heat exchanger (12), namely a low cross concentrated solution inlet pipe (55) is connected to the low-temperature heat exchanger (12); when the unit operates in a refrigerating mode, the solution circulation process is an inverted series connection process.

4. The flue gas hot water type lithium bromide absorption cold water heat pump unit according to claim 1, 2 or 3, characterized in that: a condenser water inlet pipe (50) of the condenser (31) is connected with a medium temperature water inlet pipe (52), a first switching valve (51) of the water inlet pipe is arranged on the condenser water inlet pipe (50), a condenser water inlet communicating pipe (39) with a second switching valve (38) of the water inlet pipe is connected between an absorber water outlet pipe (37) of the absorber (1) and the condenser water inlet pipe (50), and an absorber water outlet straight-through pipe (43) with a first switching valve (44) of the water outlet pipe is connected between the absorber water outlet pipe (37) and the medium temperature water outlet pipe (42); when the unit operates in a refrigerating mode, the cooling water flow of the absorber (1) and the condenser (31) is a parallel flow.

5. The flue gas hot water type lithium bromide absorption cold water heat pump unit according to claim 1 or 2, characterized in that: a water inlet pipe (50) of the condenser is connected with a water outlet pipe (37) of the absorber; when the unit operates in a refrigerating mode, the cooling water flow of the absorber (1) and the condenser (31) is a series flow.

6. The flue gas hot water type lithium bromide absorption cold water heat pump unit according to claim 1, characterized in that: a hot water inlet pipe at the low-temperature hot water side of the plate heat exchanger (33), namely a plate heat exchange water inlet pipe (48), is connected with a medium-temperature water inlet pipe (52) of the unit, and a hot water pipe second stop valve (49) is arranged on the plate heat exchange water inlet pipe (48); when the unit is in heating operation, the hot water flow of the plate heat exchanger (33), the absorber (1) and the condenser (31) is a parallel flow.

7. The flue gas hot water type lithium bromide absorption cold water heat pump unit according to claim 1, characterized in that: a second switching valve (56) of the water outlet pipe is arranged on the water outlet pipe (36) of the condenser (31), a plate heat exchange water inlet pipe (48) of the plate heat exchanger (33) is connected with the water outlet pipe (36) of the condenser, and a second stop valve (49) of the hot water pipe is arranged on the plate heat exchange water inlet pipe (48); when the unit is in heating operation, the hot water flow of the plate heat exchanger (33), the absorber (1) and the condenser (31) is a series flow.