A multi-stage absorption heat pump unit

Abstract

The application provides a multi-stage absorption heat pump unit, which comprises a multi-stage heat pump module, wherein the module comprises a first-stage heat conversion module, a second-stage heat pump module and a heat supply pipeline. In the module, each stage of absorber and evaporator, low-temperature generator and condenser are connected in pairs to enable refrigerant steam from the evaporator to be absorbed by the solution in the absorber and to enable the refrigerant steam generated by the low-temperature generator to condense in the corresponding condenser. The application combines the advantages of single-effect heat pump and double-effect heat pump through single-double-effect switching, in the single-effect mode, low-pressure steam is used to drive the recovery of waste heat to obtain hot water with high outlet water temperature, in the double-effect mode, the unit can be operated with high energy efficiency to produce air conditioning or process cold water, the unit has two functions, the equipment utilization rate is improved, and better energy saving and economic benefits are achieved.

Description

Technical Field

[0001] This invention relates to the field of energy utilization technology. Specifically, it relates to a multi-stage absorption heat pump unit. Background Technology

[0002] In existing absorption heat pump units, such as single-effect lithium bromide absorption heat pump units using lithium bromide as the working fluid, a multi-stage generator combined with a multi-stage absorption process is used to drive the process with low-pressure steam, recover various types of waste heat, and generate a heat source for centralized heating. However, the centralized heating system is idle in summer, resulting in low equipment utilization. Summary of the Invention

[0003] The purpose of this invention is to provide a multi-stage absorption heat pump unit and system, which solves the problems of absorption heat pump units being unable to provide cooling, resulting in limited application scenarios and low efficiency.

[0004] One aspect of the present invention provides a multi-stage absorption heat pump unit, comprising a multi-stage heat pump module, including: a first-stage heat conversion module, a second-stage heat pump module, and a heating pipeline, wherein: The generator in the first-stage heat conversion module is the first generator. A connecting valve is installed in the pipeline connecting the steam outlet of the first generator and the condenser inlet. The first generator is a high-temperature generator.

[0005] The generator in the second-stage heat pump module is the second generator. The tube bundle of the second generator is connected to the steam outlet of the first generator, forming a refrigerant pipeline. A high-temperature generator refrigerant steam valve is installed in the refrigerant pipeline. The second generator is a low-temperature generator.

[0006] The heating pipeline includes a first heating pipeline and a second heating pipeline. The first heating pipeline connects to the tube bundle of the first generator. The second heating pipeline connects to the tube bundle of the second generator. A switching valve is installed in the second heating pipeline. The controller output is connected to the connecting valve, the high-temperature generator refrigerant steam valve, and the switching valve.

[0007] When the setting is single-effect operation, the controller sends an opening drive message to the connecting valve, a closing drive message to the high-temperature generator refrigerant steam valve, and an opening drive message to the switching valve, so that the heat source of the first heating pipeline drives the first-stage heat conversion module to produce heat, and the heat source of the second heating pipeline drives the second-stage heat pump module to produce heat.

[0008] When the setting is in dual-effect operation mode, the controller sends a closing drive message to the connecting valve, an opening drive message to the refrigerant vapor valve of the high-temperature generator, and a closing drive message to the switching valve. This causes the first heating pipeline to heat the tube bundle of the first generator, which then generates refrigerant vapor under the action of the liquid distribution device. The refrigerant vapor then drives the second-stage heat pump module for cooling.

[0009] In one embodiment of the multi-stage absorption heat pump unit of the present invention, it further includes: a third-stage heat pump module, which includes an evaporator and an absorber. The evaporator absorbs heat from a low-temperature heat source through refrigerant water and evaporates it into water vapor, which enters the absorber. A heat conversion solution is attached to the outside of the absorber heat transfer tube bundle in the absorber. The heat conversion solution absorbs the heat released by the water vapor, thereby heating the cooling water in the absorber heat transfer tube bundle during circulation.

[0010] The multi-stage absorption heat pump unit also includes: hot water piping, which connects the absorber tube bundle of the third-stage heat pump module, the low-temperature condenser tube bundle of the second-stage heat pump module, and the high-temperature condenser tube bundle of the first-stage heat conversion module.

[0011] A series control pipeline is installed between the high-temperature condenser tube bundle of the first-stage heat conversion module and the low-temperature condenser tube bundle of the second-stage heat pump module, connecting them in series. A second valve is installed at the outlet of the condenser of the second-stage heat pump module. A parallel control pipeline is provided between the high-temperature condenser tube bundle of the first-stage heat conversion module and the low-temperature condenser tube bundle of the second-stage heat pump module to connect the high-temperature condenser tube bundle of the first-stage heat conversion module and the low-temperature condenser tube bundle of the second-stage heat pump module in parallel.

[0012] The cold water pipeline is connected to the evaporator tube bundle of the third-stage heat pump module, so that the cold water in the evaporator tube bundle releases heat to the refrigerant water in the evaporator, causing it to evaporate into water vapor, which then enters the absorber of the third-stage heat pump module and is absorbed by the solution.

[0013] In another embodiment of the multi-stage absorption heat pump unit of the present invention, a low-temperature solution heat exchange pipeline is included between the low-temperature generator solution outlet of the second-stage heat pump module and the absorber liquid distribution device of the third-stage heat pump module.

[0014] The absorber solution outlet pipe of the third-stage heat pump module is connected in parallel to the low-temperature solution heat exchange pipe and the output pipe of the low-temperature generator heat transfer tube bundle of the second-stage heat pump module. After being combined, the outlet pipe of the generator solution of the first-stage heat conversion module and the generator liquid distribution device of the first-stage heat conversion module are connected in series.

[0015] Heat exchange occurs between the cryogenic solution heat exchanger and the cryogenic solution heat exchange pipeline, and between the low-refrigerant condensate-solution heat exchanger and the output pipeline of the cryogenic generator heat transfer tube bundle of the second-stage heat pump module. Heat exchange also occurs between the high-temperature solution heat exchanger and the outlet pipeline of the generator solution of the first-stage heat conversion module.

[0016] When the setting is in dual-effect operation mode, the generator solution outlet pipeline of the third-stage heat pump module is connected to the low-temperature generator liquid distribution device of the second-stage heat pump module via a high-temperature solution heat exchanger.

[0017] When the setting is single-effect operation, the generator solution outlet pipe of the third-stage heat pump module is connected to the low-temperature generator distribution device of the second-stage heat pump module via a high-temperature solution heat exchanger. Alternatively, the generator solution outlet pipe of the third-stage heat pump module is connected to the low-temperature generator distribution device of the second-stage heat pump module.

[0018] In another embodiment of the multi-stage absorption heat pump unit of the present invention, the condenser pipeline of the first-stage heat conversion module is connected to the refrigerant water pipeline of the condensate in the second-stage heat pump module, and then connected to the evaporator pipeline of the third-stage heat pump module.

[0019] In another embodiment of the multi-stage absorption heat pump unit of the present invention, the second-stage heat pump module includes multiple second-stage heat pump modules.

[0020] In dual-effect mode, the refrigerant water in the low-temperature generating tube bundle of the multi-stage second-stage heat pump module is collected through the manifold and then exchanges heat with the low-temperature solution heat exchange pipeline through the low-generation refrigerant condensate-solution heat exchanger, thereby heating the solution in the low-generation refrigerant condensate-solution heat exchanger. The manifold is connected to the condenser pipeline in the second-stage heat pump module.

[0021] In another embodiment of the multi-stage absorption heat pump unit of the present invention, a second inlet electric valve is provided at the pipeline inlet of the generator tube bundle in the multi-stage second-stage heat pump module.

[0022] In another embodiment of the multi-stage absorption heat pump unit of the present invention, when the set state is the dual-effect operation state, the controller sends a closing drive information to the first bypass valve, the high-temperature condenser tube bundle outlet valve and the high-temperature condenser inlet valve, so as to close the first bypass valve, the high-temperature condenser tube bundle outlet valve and the high-temperature condenser inlet valve.

[0023] Send an opening drive message to the second bypass valve to heat the hot water in the absorber tube bundle of the third-stage heat pump module and the condenser of the second-stage heat pump module.

[0024] When the setting is single-effect operation, the controller controls the valve so that hot water flows through the absorber tube bundle of the third-stage heat pump module, then through the low-temperature condenser tube bundle of the second-stage heat pump module and the high-temperature condenser tube bundle of the first-stage heat conversion module.

[0025] In another embodiment of the multi-stage absorption heat pump unit of the present invention, when the set state is single-effect operation, the controller sends a closing drive information to the hot water inlet valve, the second valve, and the second inlet electric valve, so that the hot water is heated in the absorber tube bundle of the third-stage heat pump module and the high-temperature condenser tube bundle of the multi-stage first-stage heat conversion module.

[0026] In another embodiment of the multi-stage absorption heat pump unit of the present invention, when the set state is single-effect operation, the controller controls the connection of the high-pressure steam, high-temperature hot water, gas or high-temperature flue gas pipeline and the first heating pipeline. The controller controls the connection of the steam or exhaust steam pipeline and the second heating pipeline.

[0027] In another embodiment of the multi-stage absorption heat pump unit of the present invention, when the set state is the dual-effect operation state, the controller controls the outlet pipe of the second heating pipeline and the heat transfer tube bundle of the low temperature generator to be in a vacuum state.

[0028] When the setting is single-effect operation, the controller controls the outlet pipe of the second heating pipeline and the heat transfer tube bundle of the low-temperature generator to be in a non-vacuum state.

[0029] In another embodiment of the multi-stage absorption heat pump unit of the present invention, it further includes: a solution pump, which is disposed between the absorber and generator in the third-stage heat pump module and the first-stage heat conversion module and the second-stage heat pump module, to provide circulating power from the absorber to the generator; and a refrigerant pump, which is disposed between the evaporator shell and the evaporator liquid distribution device in the third-stage heat pump module to provide power for refrigerant liquid distribution. The following text will further explain the characteristics, technical features, advantages, and implementation methods of multi-stage absorption heat pump units and systems in a clear and easy-to-understand manner, with the aid of accompanying drawings. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a multi-stage absorption heat pump unit according to an optional embodiment of the present invention.

[0031] Figure 2 This is a schematic diagram of the structure of a multi-stage absorption heat pump unit, which is another optional embodiment of the present invention.

[0032] Figure 3 This is a schematic diagram of the structure of a multi-stage absorption heat pump unit, which is another optional embodiment of the present invention. Detailed Implementation

[0033] To provide a clearer understanding of the technical features, objectives, and effects of the invention, specific embodiments of the invention are now described with reference to the accompanying drawings. In the drawings, the same reference numerals indicate components with the same or similar structures but the same function.

[0034] In this document, "illustrative" means "serving as an example, illustration, or description," and any illustrations or embodiments described herein as "illustrative" should not be construed as a more preferred or advantageous technical solution. For the sake of brevity, each figure only schematically shows the parts relevant to this exemplary embodiment, and they do not represent the actual structure or true proportions of the product.

[0035] like Figure 1 As shown, one aspect of the present invention provides a multi-stage absorption heat pump unit, which includes a multi-stage heat pump module, comprising: a first-stage heat conversion module 3, a second-stage heat pump module 2, and a heating pipeline 4, wherein: The generator in the first-stage heat conversion module 3 is the first generator. A connecting valve 11 is installed in the pipeline connecting the steam outlet of the first generator and the condenser inlet. The first generator is a high-temperature generator.

[0036] The generator in the second-stage heat pump module 2 is a second generator. The tube bundle of the second generator is connected to the steam outlet of the first generator, forming a refrigerant pipeline. A high-temperature generator refrigerant steam valve 12 is installed in the refrigerant pipeline. The second generator is a low-temperature generator.

[0037] The heating pipeline 4 includes a first heating pipeline 41 and a second heating pipeline 42. The first heating pipeline 41 is connected to the tube bundle of the first generator. The second heating pipeline 42 is connected to the tube bundle of the second generator. A switching valve is installed in the second heating pipeline 42.

[0038] The controller output is connected to the connecting valve 11, the high-temperature generator refrigerant steam valve 12, and the switching valve. When the set state is single-effect operation, the controller sends an opening drive information to the connecting valve 11, a closing drive information to the high-temperature generator refrigerant steam valve 12, and an opening drive information to the switching valve, so that the heat source of the first heating pipeline 41 drives the first-stage heat conversion module 3 to produce heat, and the heat source of the second heating pipeline 42 drives the second-stage heat pump module 2 to produce heat.

[0039] When the setting is in dual-effect operation mode, the controller sends a closing drive information to the connecting valve 11, an opening drive information to the high-temperature generator refrigerant vapor valve 12, and a closing drive information to the switching valve. This causes the first heating pipeline 41 to heat the tube bundle of the first generator, which then generates refrigerant vapor under the action of the liquid distribution device. The refrigerant vapor then drives the second-stage heat pump module 2 for cooling.

[0040] This invention combines the advantages of single-effect and dual-effect heat pumps by switching between single and dual effects. In single-effect mode, it can use low-pressure steam to drive the recovery of waste heat to obtain hot water with a high outlet temperature. In dual-effect mode, it can operate with high energy efficiency to produce chilled water for air conditioning or process use. It can serve two purposes in one machine, improve equipment utilization, and achieve better energy saving and economic benefits.

[0041] To address the aforementioned problems, this invention provides a multi-stage absorption heat pump unit, comprising: a third-stage heat pump module, a second-stage heat pump module, and a first-stage heat conversion module, each having at least one stage. Within each module, the absorber and evaporator, as well as the low-temperature generator and condenser, are connected in a one-to-one correspondence, so that refrigerant vapor is absorbed by the solution from the evaporator to the absorber, and that the refrigerant vapor generated by the low-temperature generator condenses the solution and enters the corresponding condenser for condensation.

[0042] In one embodiment of the present invention, a multi-stage absorption heat pump unit is provided, comprising: a third-stage heat pump module 1, a second-stage heat pump module, and a first-stage heat conversion module, each having at least one stage. When the unit operates in single-effect mode, the first-stage heat conversion module has the same function as the second-stage heat pump module and is connected in series after the second-stage heat pump module; each stage absorber and evaporator, low-temperature generator and condenser are connected in a one-to-one correspondence, so that refrigerant vapor is absorbed by the solution from the evaporator to the absorber and that the refrigerant vapor generated by the low-temperature generator condenses the solution enters the corresponding condenser for condensation.

[0043] In the first-stage heat conversion module, a refrigerant vapor valve is installed between the generator and the condenser of this module. A refrigerant vapor valve is also installed between the refrigerant vapor outlet of the high-temperature generator and the generator of the second-stage heat pump module. The inlet and outlet of the low-temperature generator of each stage of the second-stage heat pump module are equipped with external drive heat source inlet and outlet and switching valve.

[0044] In one embodiment of the multi-stage absorption heat pump unit of the present invention, it further includes: a third-stage heat pump module 1, which includes an evaporator and an absorber. The evaporator absorbs heat from a low-temperature heat source through refrigerant water and evaporates it into water vapor, which enters the absorber. A heat conversion solution is attached to the outside of the absorber heat transfer tube bundle 1-1 in the absorber. The heat conversion solution absorbs the heat released by the water vapor, thereby heating the cooling water in the absorber heat transfer tube bundle 1-1 in circulation.

[0045] In one embodiment, the third-stage heat pump module 1 includes an absorber heat transfer tube bundle 1-1, an evaporator heat transfer tube bundle 1-2, an absorber liquid distribution device 1-3, and an evaporator liquid distribution device 1-4; the second-stage heat pump module includes a low-temperature condenser tube bundle 2-1, a low-temperature generator heat transfer tube bundle 2-2, and a low-temperature generator liquid distribution device 2-3; and the first-stage heat conversion module includes a high-temperature condenser tube bundle 3-1, a high-temperature generator tube bundle 3-2, and a high-temperature generator liquid distribution device 3-3.

[0046] The multi-stage absorption heat pump unit also includes: a hot water pipe 5, which connects to the absorber tube bundle of the third-stage heat pump module 1, the low-temperature condenser tube bundle 2-1 of the second-stage heat pump module 2, and the high-temperature condenser tube bundle 3-1 of the first-stage heat conversion module 3.

[0047] A series control pipeline is installed between the condenser tube bundle of the first-stage heat conversion module 3 and the condenser tube bundle of the second-stage heat pump module 2, connecting the high-temperature condenser tube bundle 3-1 of the first-stage heat conversion module 3 and the low-temperature condenser tube bundle 2-1 of the second-stage heat pump module 2 in series. A second valve 17 is installed at the outlet of the condenser of the second-stage heat pump module 2. A parallel control pipeline is provided between the condenser tube bundle of the first-stage heat conversion module 3 and the low-temperature condenser tube bundle 2-1 of the second-stage heat pump module 2, so that the high-temperature condenser tube bundle 3-1 of the first-stage heat conversion module 3 and the low-temperature condenser tube bundle 2-1 of the second-stage heat pump module 2 are connected in parallel.

[0048] The cold water pipeline is connected to the evaporator tube bundle of the third-stage heat pump module 1, so that the cold water in the evaporator tube bundle releases heat to the refrigerant water in the evaporator, causing it to evaporate into water vapor, which then enters the absorber of the third-stage heat pump module 1 and is absorbed by the solution.

[0049] In one embodiment, when the unit is operating in single-effect mode, the valve 11 connecting the generator and condenser in the first-stage heat conversion module is opened, and all the refrigerant vapor generated by the generator in the first-stage heat conversion module enters the condenser of this module for condensation.

[0050] When the inlet and outlet valves 13 and 14 of the external heating pipeline 4 or the second driving heat source pipeline 7 are connected to the low-temperature generators at each stage, the valve 15 connecting the outlet of the low-temperature generator heat transfer tube bundle to the low-temperature refrigerant condensate-solution heat exchanger is closed. The generator of each stage of the second-stage heat pump module uses the external heat source to drive the heating of the concentrated solution. At this time, the first-stage heat conversion module and the second-stage heat pump module have the same function. Hot water is heated in each stage of the absorber, low-temperature condenser and high-temperature condenser in sequence.

[0051] In one embodiment, during dual-effect operation, the valve 11 connecting the generator and the condenser of the first-stage heat conversion module is closed, and the valve 12 connecting the high-temperature generator refrigerant vapor outlet and the generator of the second-stage heat pump module is opened, allowing the refrigerant vapor generated by the concentrated solution of the high-temperature generator to enter each low-temperature generator as a driving heat source.

[0052] At the same time, the inlet and outlet valves 13 and 14 of the external heating pipeline connected to the low-temperature generators at each level are closed, and the valve 15 connecting the outlet of the heat transfer tube bundle of the low-temperature generator to the low-power refrigerant condensate-solution heat exchanger is opened. The refrigerant vapor generated in each high-temperature generator heats and concentrates the solution in each low-temperature generator, then enters the low-power refrigerant condensate-solution heat exchanger 8-3 to continue heating the dilute solution, and then enters the condenser after throttling.

[0053] In another embodiment of the multi-stage absorption heat pump unit of the present invention, a low-temperature solution heat exchange pipeline is included between the low-temperature generator solution outlet of the second-stage heat pump module 2 and the absorber liquid distribution device 1-3 of the third-stage heat pump module 1.

[0054] The absorber solution outlet pipe of the third-stage heat pump module 1 is connected in parallel to the low-temperature solution heat exchange pipe and the output pipe of the low-temperature generator heat transfer tube bundle 2-2 of the second-stage heat pump module 2. After being combined, the outlet pipe of the generator solution of the first-stage heat conversion module 3 and the generator liquid distribution device 3-3 of the first-stage heat conversion module 3 are connected in series.

[0055] Heat exchange occurs between the cryogenic solution heat exchanger 8-2 and the cryogenic solution heat exchange pipeline, and between the cryogenic generator heat transfer tube bundle 2-2 of the second-stage heat pump module 2 and the output pipeline of the cryogenic generator heat transfer tube bundle 2-2 of the low-refrigerant condensate-solution heat exchanger 8-3. Heat exchange also occurs between the high-temperature solution heat exchanger 8-1 and the generator solution outlet pipeline of the first-stage heat conversion module 3.

[0056] When the setting is in dual-effect operation mode, the generator solution outlet pipeline of the third-stage heat pump module 1 is connected to the low-temperature generator liquid distribution device 2-3 of the second-stage heat pump module 2 via the high-temperature solution heat exchanger 8-1.

[0057] When the setting is single-effect operation, the generator solution outlet pipe of the third-stage heat pump module 1 is connected to the low-temperature generator liquid distribution device 2-3 of the second-stage heat pump module 2 via the high-temperature solution heat exchanger 8-1. Alternatively, the generator solution outlet pipe of the third-stage heat pump module 1 is connected to the low-temperature generator liquid distribution device 2-3 of the second-stage heat pump module 2.

[0058] In another embodiment of the multi-stage absorption heat pump unit of the present invention, the condenser pipeline of the first-stage heat conversion module 3 is connected to the refrigerant water pipeline of the condensate in the second-stage heat pump module 2, and then connected to the evaporator pipeline of the third-stage heat pump module 1.

[0059] In another embodiment of the multi-stage absorption heat pump unit of the present invention, the second-stage heat pump module 2 includes multiple second-stage heat pump modules 2.

[0060] In dual-effect mode, the refrigerant water in the low-temperature generating tube bundle of the multi-stage second-stage heat pump module 2 is collected through the manifold and then exchanges heat with the low-temperature solution heat exchange pipeline through the low-refrigerant condensate-solution heat exchanger 8-3, thereby heating the solution in the low-refrigerant condensate-solution heat exchanger 8-3. The manifold is connected to the condensation pipeline in the second-stage heat pump module 2.

[0061] In another embodiment of the multi-stage absorption heat pump unit of the present invention, a second inlet electric valve 22 is provided at the pipeline inlet of the generator tube bundle in the multi-stage second-stage heat pump module 2.

[0062] In another embodiment of the multi-stage absorption heat pump unit of the present invention, when the set state is the dual-effect operation state, the controller sends a closing drive information to the first bypass valve 18, the high-temperature condenser tube bundle outlet valve 21 and the high-temperature condenser inlet valve 19 to close the first bypass valve 18, the high-temperature condenser tube bundle outlet valve 21 and the high-temperature condenser inlet valve 19.

[0063] An opening drive message is sent to the second bypass valve 20 to heat the hot water in the absorber tube bundle of the third-stage heat pump module 1 and the condenser of the second-stage heat pump module 2.

[0064] When the setting is single-effect operation, the controller controls the valve so that the hot water flows through the absorber tube bundle of the third-stage heat pump module 1, and then through the low-temperature condenser tube bundle 2-1 of the second-stage heat pump module 2 and the high-temperature condenser tube bundle 3-1 of the first-stage heat conversion module 3.

[0065] In another embodiment of the multi-stage absorption heat pump unit of the present invention, when the set state is single-effect operation, the controller sends a closing drive information to the hot water inlet valve 16, the second valve 17 and the second inlet electric valve 22, so that the hot water is heated in the absorber tube bundle of the third-stage heat pump module 1 and the high-temperature condenser tube bundle 3-1 of the multi-stage first-stage heat conversion module 3.

[0066] In another embodiment of the multi-stage absorption heat pump unit of the present invention, when the set state is single-effect operation, the controller controls the connection of the high-pressure steam, high-temperature hot water, gas or high-temperature flue gas heating pipeline 4 and the first heating pipeline 41. The controller controls the connection of the steam or exhaust steam heating pipeline 4 and the second heating pipeline 42.

[0067] In another embodiment of the multi-stage absorption heat pump unit of the present invention, when the set state is the dual-effect operation state, the controller controls the outlet pipe of the second heating pipeline 42 and the heat transfer tube bundle of the low temperature generator to be in a vacuum state.

[0068] When the setting is single-effect operation, the controller controls the outlet pipe of the second heating pipeline 42 and the heat transfer tube bundle of the low-temperature generator to be in a non-vacuum state.

[0069] In another embodiment of the multi-stage absorption heat pump unit of the present invention, it further includes: Solution pump 101, located between the absorber and generator in the third-stage heat pump module 1 and the first-stage heat conversion module 3 and the second-stage heat pump module 2, provides circulating power from the absorber to the generator. Refrigerant pump 102, located between the evaporator shell and the evaporator liquid distribution device in the third-stage heat pump module 1, provides power for refrigerant liquid distribution.

[0070] In one embodiment of the present invention, an operating mode switching and bypass valve is provided between the absorber of the third-stage heat pump module 1, the low-temperature condenser of the second-stage heat pump module 2, and the high-temperature condenser of the first-stage heat conversion module 3: a hot water inlet valve 16, a second valve 17, and a first bypass valve 18 of the condenser of the second-stage heat pump module; and valves between the high- and low-temperature condensers, namely, a high-temperature condenser inlet valve 19, a second bypass valve 20 for the hot water inlet of the condenser of the first-stage heat conversion module, and a high-temperature condenser tube bundle outlet valve 21.

[0071] During dual-effect operation, the high-temperature condenser inlet valve 19 and the high-temperature condenser tube bundle outlet valve 21 of the first-stage heat conversion module are closed, and the second bypass valve 20 is open. Hot water is only heated in the absorbers of the third-stage heat pump module 1 and the condensers of the second-stage heat pump modules.

[0072] In single-effect operation, the hot water pipeline is generally connected in series between the absorber heat transfer tube bundle 1-1, the low-temperature condenser tube bundle 2-1, and the high-temperature condenser tube bundle 3-1. The hot water inlet valve 16, the second valve 17, the high-temperature condenser inlet valve 19, and the high-temperature condenser tube bundle outlet valve 21 of the high-temperature and low-temperature condensers are all open, while the first bypass valve 18 and the second bypass valve 20 are both closed. The hot water is heated sequentially in the absorber, the low-temperature condenser, and the high-temperature condenser.

[0073] In one embodiment, the hot water pipeline can also be connected to the aforementioned tube bundle in parallel or series-parallel configuration. For example, when the hot water first passes through the absorber tube bundles 1-1 at each stage, and then is connected in parallel to the low-temperature condenser tube bundle 2-1 and the high-temperature condenser tube bundle 3-1, the hot water inlet valve 16, the second valve 17, the first bypass valve 18, the second bypass valve 20, and the high-temperature condenser tube bundle outlet valve 21 can be opened, while the high-temperature condenser inlet valve 19 is closed. If the absorber tube bundle 1-1 is also connected in parallel with the low-temperature and high-temperature condensers, additional switching pipelines and valves are required.

[0074] In one embodiment, when the unit load is low, the condenser hot water inlet valve 16, the second valve 17, the condenser inlet valve 19 of the second-stage heat pump module and the high-temperature condenser inlet valve 19 of the first-stage heat conversion module, the second bypass valve 20 of the condenser hot water of the first-stage heat conversion module, and the low-temperature generator drive heat source inlet valve 13 of the second-stage heat pump module can be closed. The condenser hot water first bypass valve 18 of the second-stage heat pump module and the high-temperature condenser tube bundle outlet valve 21 of the first-stage heat conversion module can be opened. The hot water is only heated in the absorber of the third-stage heat pump module 1 and the condenser of the first-stage heat conversion module.

[0075] In one embodiment, cold water flows in series or in parallel between the evaporator heat transfer tube bundles 1-2 of each level of the third-stage heat pump module 1. When connected in series, the flow direction can be from the evaporator of the lowest-level module to the evaporator of the highest-level module or in the opposite direction.

[0076] In one embodiment, the system further includes solution heat exchangers, namely a high-temperature solution heat exchanger 8-1, a low-temperature solution heat exchanger 8-2, and a low-refrigerant condensate-solution heat exchanger 8-3. In single and double-effect modes, the circulation method is generally as follows: In dual-effect operation, the absorber solution outlet pipeline of the lowest-level third-stage heat pump module 1 is connected in parallel and first passes through the low-temperature solution heat exchanger 8-2 and the low-temperature refrigerant condensate-solution heat exchanger 8-3, where it is heated by the concentrated solution and refrigerant water from the low-temperature generator, respectively. Then it enters the high-temperature solution heat exchanger 8-1 and is heated by the solution at the outlet of the high-temperature generator. Finally, it is connected to the liquid distribution device 3-3 of the high-temperature generator of the highest-level first-stage heat conversion module.

[0077] The solution flows continuously between the high-temperature generators at each stage, and is concentrated sequentially in each high-temperature generator. The generated refrigerant vapor enters the heat transfer tube bundles 2-2 of each low-temperature generator via the refrigerant vapor valve 12 of the high-temperature generator, serving as a driving heat source to heat the concentrated solution. The solution outlet pipe of the generator in the lowest-level heat conversion module is connected to the liquid distribution device 2-3 of the low-temperature generator in the highest-level second-level heat pump module via the high-temperature solution heat exchanger 8-1. The solution flows continuously between the low-temperature generators at each stage, and is concentrated sequentially in each low-temperature generator. The generated refrigerant vapor enters the corresponding condensers at each stage for condensation.

[0078] The generator solution outlet pipe of the lowest-level second-stage heat pump module is connected to the absorption and distribution device 1-3 of the highest-level third-stage heat pump module 1 via a low-temperature solution heat exchanger 8-2. The solution flows in series between the absorbers of each stage, and the solution absorbs water vapor from each evaporator in turn to become a dilute solution.

[0079] In single-effect operation, the absorber solution outlet pipe of the lowest-level third-stage heat pump module 1 is connected in series or parallel to the high-temperature generator liquid distribution device 3-3 of the highest-level first-stage heat conversion module via the low-temperature solution heat exchanger 8-2 and the high-temperature solution heat exchanger 8-1. The solution flows in series between the high-temperature generators of each stage, and the solution is concentrated in the high-temperature generators in sequence. The generated refrigerant vapor enters the condenser corresponding to this module for condensation.

[0080] The generator solution outlet pipe of the lowest first-stage heat conversion module can be connected to the low-temperature generator liquid distribution device 2-3 of the highest second-stage heat pump module, with or without passing through the high-temperature solution heat exchanger 8-1. The solution flows in series between the low-temperature generators of each stage, and the solution is concentrated in the low-temperature generators in sequence. The generated refrigerant vapor enters the corresponding condenser tube bundles of each stage for condensation.

[0081] The generator solution outlet pipe of the lowest-level second-stage heat pump module is connected to the absorption and distribution device 1-3 of the highest-level third-stage heat pump module 1 via the low-temperature solution heat exchanger 8-2, or with or without passing through the high-temperature solution heat exchanger 8-1. The solution flows in series between the absorbers of each stage, and the solution absorbs water vapor from each evaporator in turn to become a dilute solution.

[0082] In one embodiment, the condenser refrigerant water pipelines of the first-stage heat conversion module and the low-temperature generator-condenser are connected sequentially from top to bottom, and finally enter the evaporator of the third-stage heat pump module 1 from the condenser of the lowest-level second-stage heat pump module. The upper-level evaporator can replenish the refrigerant water to the lower-level evaporator.

[0083] In dual-effect mode, the refrigerant water in the heat transfer tube bundle of the low-temperature generator of each stage of the second-stage heat pump module is collected and enters the low-temperature refrigerant condensate-solution heat exchanger 8-3 to be cooled by the solution. After throttling, it enters the condenser of the lowest stage of the second-stage heat pump module.

[0084] In one embodiment, a second inlet electric valve 22 is provided at the inlet of the low-temperature generator heat transfer tube bundle 2-2 of each second-stage heat pump module 2, which can cut off the driving heat source input or adjust parameters such as the flow rate and pressure of the driving heat source input according to load changes.

[0085] In one embodiment, during single-effect operation, the high-temperature generator and the low-temperature generator use different types of driving heat sources. The driving heat source for the high-temperature generator can be high-pressure steam, high-temperature hot water, gas, or high-temperature flue gas, while the low-temperature generator uses steam or exhaust steam that is structurally compatible and feasible as its driving heat source.

[0086] In one embodiment, during dual-effect operation, the inlet and outlet pipes of the driving heat source of each stage of the cryogenic generator and the heat transfer tube bundle of the cryogenic generator are in a vacuum state. During single-effect operation, they are in a non-vacuum state. Accordingly, the inlet and outlet pipes of the driving heat source of each stage of the cryogenic generator are equipped with vacuuming pipes, vacuum valves and pressure sensors, as well as vacuuming equipment and vacuum detection devices, to extract non-condensable gases such as air from the space of the aforementioned pipes and tube bundles when the unit switches from single-effect operation to dual-effect operation.

[0087] In one embodiment, the unit further includes a solution pump 101 and a refrigerant pump 102. The solution pump is connected between the bottom of the absorber housing of the lowest-level third-stage heat pump module and the low-temperature solution heat exchanger 8-2 and the low-temperature refrigerant condensate-solution heat exchanger 8-3, providing power for the circulation of solution from the absorber to the generator. Each evaporator stage is equipped with a refrigerant pump 102, or multiple evaporators share a common refrigerant pump 102. The refrigerant pump 102 is connected between the evaporator housing and the evaporator liquid distribution device 1-4, providing power for refrigerant liquid distribution.

[0088] In one embodiment, the solution is circulated in parallel, series-parallel, or reverse series configurations among the various absorbers, low-temperature generators, and high-temperature generators. In this case, additional solution pumps, valves, and pipelines are required.

[0089] like Figure 1 As shown, in one optional embodiment of the present invention, a multi-stage absorption heat pump unit is provided, including: a two-stage third-stage heat pump module, a second-stage heat pump module 2, a first-stage heat conversion module 3, a heating pipeline 4, a hot water pipeline 5, a cold water pipeline 6, a high-temperature solution heat exchanger 8-1, a low-temperature solution heat exchanger 8-2, a low-temperature refrigerant condensate-solution heat exchanger 8-3, a solution pump 101, a refrigerant pump 102, a connecting valve 11 for the refrigerant vapor of the high-temperature generator, a refrigerant vapor valve 12 for the high-temperature generator, inlet and outlet valves and switching valves 13, 14, and 15 for the low-temperature generator driving heat source, a hot water inlet valve 16 for the low-temperature condenser, a second valve 17, a first bypass valve 18, an inlet valve 19 for the high-temperature condenser, a second bypass valve 20, an outlet valve 21 for the high-temperature condenser tube bundle, a second inlet electric valve 22 for the inlet of the low-temperature generator heat transfer tube bundle, and a low-temperature generator heat transfer tube bundle 2-2 and a liquid distribution device in each module.

[0090] The driving heat source is steam, which is connected to a high-temperature generator and two-stage low-temperature generators via heating pipeline 4. Valves 13 and 14 are installed between heating pipeline 4 and the two low-temperature generators. A second inlet electric valve 22 is installed at the inlet of the heat transfer tube bundle of each low-temperature generator. During single-effect operation, the refrigerant steam connecting valve 11 of the high-temperature generator is open, and the refrigerant steam valve 12 of the high-temperature generator is closed. All the refrigerant steam generated by the generator in the first-stage heat conversion module enters the condenser of this module for condensation.

[0091] The inlet and outlet switching valves 13 and 14 of the heating pipeline 4 connected to the two-stage low-temperature generator are open. The valve 15 connecting the outlet of the low-temperature generator heat transfer tube bundle to the low-temperature refrigerant condensate-solution heat exchanger is closed. The generator of the second-stage heat pump module uses an external heat source (steam) to drive the heating of the concentrated solution. At this time, the first-stage heat conversion module and the second-stage heat pump module have the same function. The hot water inlet valve 16, the second valve 17, the high-temperature condenser inlet valve 19, and the high-temperature condenser tube bundle outlet valve 21 are open. The first bypass valve 18 and the second bypass valve 20 are closed. The hot water is heated in sequence in the two-stage absorber, the two-stage low-temperature condenser, and the high-temperature condenser.

[0092] The solution originates from the absorber outlet pipe of the lowest-level third-stage heat pump module 1, passes through the solution pump 101 in series, and connects to the high-temperature generator distribution device 3-3 via the low-temperature solution heat exchanger 8-2 and the high-temperature solution heat exchanger 8-1. The high-temperature generator solution outlet pipe can connect to the low-temperature generator distribution device 2-3 of the highest-level second-stage heat pump module via the high-temperature solution heat exchanger 8-1. The solution flows in series between the two low-temperature generators, and is concentrated sequentially in the low-temperature generators. The generated refrigerant vapor enters the corresponding condensers at each stage for condensation.

[0093] The generator solution outlet pipe of the lowest-level second-stage heat pump module is connected to the absorption and distribution device 1-3 of the highest-level third-stage heat pump module 1 via a low-temperature solution heat exchanger 8-2. The solution flows in series between the two absorbers, and the solution absorbs water vapor from the evaporator in sequence to become a dilute solution, thus completing the solution cycle.

[0094] The refrigerant water generated by the condenser of the first-stage heat conversion module enters the condenser of the top-level second-stage heat pump module. After merging with the refrigerant water in this condenser, it enters the condenser of the next-stage low-temperature generator-condenser. Then, after being throttled, it enters the evaporator of the top-level third-stage heat pump module 1. Part of the refrigerant water evaporates in the previous-stage evaporator, and the remainder is supplied to the next-stage evaporator. Each evaporator is equipped with a refrigerant pump 102, which is connected to the evaporator liquid distribution device 1-4. The refrigerant water after the evaporator enters the corresponding absorber, completing the refrigerant cycle.

[0095] In one embodiment, depending on the operating conditions, the hot water can be connected in parallel with the low-temperature condenser and the high-temperature condenser, or only the high-temperature condenser can be used, which only requires adjusting the state of valves 16-21.

[0096] When operating in dual-effect mode, the refrigerant steam connecting valve 11 of the high-temperature generator is closed, and the refrigerant steam valve 12 of the high-temperature generator is open. At this time, the refrigerant steam does not enter the condenser of this module. The corresponding high-temperature condenser inlet valve 19 and high-temperature condenser tube bundle outlet valve 21 are closed, and the second bypass valve 20 is open. The hot water does not pass through the condenser of the first-stage heat conversion module, but is heated only through the two-stage absorber and the two-stage low-temperature condenser. The corresponding hot water inlet valve 16, the second valve 17, and the second bypass valve 20 are open.

[0097] The low-temperature generator of the second-stage heat pump module drives the heat source inlet and outlet valves 13 and 14 to close. The low-temperature generator uses refrigerant vapor from the high-temperature generator to heat the concentrated solution. The second inlet electric valve 22 at the inlet of the heat transfer tube bundle 2-2 of the two-stage low-temperature generator can regulate the flow rate and pressure of the refrigerant vapor entering the two-stage low-temperature generator to match different operating conditions.

[0098] The solution circulation is as follows: The absorber solution outlet pipeline of the lowest level third-stage heat pump module 1 passes through the solution pump 101 in parallel, first through the low-temperature solution heat exchanger 8-2 and the low-temperature refrigerant condensate-solution heat exchanger 8-3, where it is heated by the concentrated solution and refrigerant water from the low-temperature generator, respectively. Then it enters the high-temperature solution heat exchanger 8-1, and then connects to the high-temperature generator liquid distribution device 3-3 of the first-stage heat conversion module.

[0099] After being concentrated in the high-temperature generator, the solution is connected to the low-temperature generator distribution device 2-3 of the uppermost second-stage heat pump module via the high-temperature solution heat exchanger 8-1. The solution flows continuously between the two low-temperature generators, and is concentrated sequentially in both low-temperature generators. The generated refrigerant vapor enters the corresponding condenser and condenses. The solution outlet pipe of the generator of the lowermost second-stage heat pump module is connected to the absorption distribution device 1-3 of the uppermost third-stage heat pump module 1 via the low-temperature solution heat exchanger 8-2. The solution flows continuously between the two absorbers, and absorbs water vapor from the evaporator sequentially to become a dilute solution, completing the solution cycle.

[0100] The refrigerant cycle is as follows: The refrigerant water in the heat transfer tube bundle 2-2 of the low-temperature generator of the two-stage second-stage heat pump module is collected and enters the low-temperature refrigerant condensate-solution heat exchanger 8-3 through valve 15. It is cooled by the solution and then enters the condenser of the lowest-stage second-stage heat pump module after throttling. Then, it enters the evaporator of the highest-stage third-stage heat pump module 1 after throttling. A portion of the refrigerant water evaporates in the upper-stage evaporator, and the remainder is supplied to the lower-stage evaporator. Each stage of evaporator is equipped with a refrigerant pump 102, which is connected to the evaporator liquid distribution device 1-4. The refrigerant water after the evaporator enters the corresponding absorber to complete the refrigerant cycle.

[0101] In one embodiment, the cold water pipeline flows in series between the evaporator tube bundles 1-2 of the two-stage third-stage heat pump module 1, with the flow direction from bottom to top.

[0102] like Figure 2 As shown, in another optional embodiment of the present invention, a multi-stage absorption heat pump unit is provided, including: a two-stage third-stage heat pump module, a second-stage heat pump module 2, a first-stage heat conversion module 3, a heating pipeline 4, a hot water pipeline 5, a cold water pipeline 6, a second driving heat source pipeline 7, a high-temperature solution heat exchanger 8-1, a low-temperature solution heat exchanger 8-2, a low-temperature refrigerant condensate-solution heat exchanger 8-3, a solution pump 101, a refrigerant pump 102, a connecting valve 11 for the refrigerant vapor of the high-temperature generator, a refrigerant vapor valve 12 for the high-temperature generator, inlet and outlet valves and switching valves 13, 14, and 15 for the driving heat source of the low-temperature generator, a hot water inlet valve 16 for the high-temperature and low-temperature condensers, a second valve 17, a first bypass valve 18, an inlet valve 19 for the high-temperature condenser, a second bypass valve 20, an outlet valve 21 for the high-temperature condenser tube bundle, a second inlet electric valve 22 for the inlet of the low-temperature generator heat transfer tube bundle, and a low-temperature generator heat transfer tube bundle 2-2 and a liquid distribution device in each module.

[0103] The difference from Example 1 is that, during single-effect operation, the driving heat sources for the high-temperature generator and the low-temperature generator are different. The high-temperature generator is driven by high-pressure steam or gas, while the low-temperature generator is driven by low-pressure steam. The connection methods for other hot water pipes, solution circulation, refrigerant circulation, and cold water pipes are the same as in Example 1, and will not be repeated here.

[0104] like Figure 3 As shown, in another optional embodiment of the present invention, a multi-stage absorption heat pump unit is provided, including: two-stage third-stage heat pump modules, one-stage second-stage heat pump module 2, two-stage first-stage heat conversion modules 3, heating pipeline 4, hot water pipeline 5, cold water pipeline 6, high-temperature solution heat exchanger 8-1, low-temperature solution heat exchanger 8-2, low-temperature refrigerant condensate-solution heat exchanger 8-3, solution pump 101, refrigerant pump 102, high-temperature generator refrigerant vapor connecting valve 11, high-temperature generator refrigerant vapor valve 12, low-temperature generator drive heat source inlet and outlet and switching valves 13, 14, 15, low-temperature generator hot water inlet valve 16, second valve 17, first bypass valve 18, high-temperature condenser inlet valve 19, second bypass valve 20, high-temperature condenser tube bundle outlet valve 21, low-temperature generator heat transfer tube bundle inlet second inlet electric valve 22, and low-temperature generator heat transfer tube bundle 2-2 and liquid distribution device in each module.

[0105] The difference from Embodiment 1 lies in the different matching relationships between the number of the second-stage heat pump module 2 and the first-stage heat conversion module 3. In specific design, the number of the three modules, the configuration of the heat transfer tube bundles of each module, and the operating condition switching valves can be matched according to the requirements of the operating conditions. The connection methods of other hot water pipelines, solution circulation, refrigerant circulation, and cold water pipelines are the same as in Embodiment 1, and will not be described again.

[0106] The multi-stage absorption heat pump unit provided in this embodiment of the invention is not limited to... Figures 1-3 The optional embodiment shown includes at least one first-stage heat conversion module, at least one second-stage heat pump module, at least one third-stage heat pump module 1, and a single / dual-effect mode switching valve. In single-effect mode, the generators of all second-stage heat pump modules are driven by an external heat source. The refrigerant vapor generated by the concentrated solution in the generators of the high / second-stage heat pump modules enters the corresponding condenser for condensation. Hot water flows in series or parallel through the absorbers and condensers at each stage, cooling the refrigerant vapor. Higher-temperature hot water can be generated using low-pressure steam.

[0107] When the unit operates in dual-effect mode, the refrigerant vapor generated by the generator of the first-stage heat conversion module no longer enters the condenser of the corresponding module. Instead, it enters the generator tube bundle of each stage of the low-temperature generator-condenser module through a switching valve. At the same time, the generators of each stage of the low-temperature generator-condenser module no longer receive external heat sources. The refrigerant vapor generated by the concentrated solution of the low-temperature generator enters the corresponding condenser for condensation. Hot water flows in series or parallel in each stage of the absorber and low-pressure condenser to cool the refrigerant vapor. The hot water does not enter the condenser of each stage of the first-stage heat conversion module.

[0108] Solution piping is connected between each stage of absorber and generator in series, parallel, or series-parallel configurations. Cold water flows in series or parallel within the evaporators of each stage of the third-stage heat pump module 1. Single / dual-effect mode switching matches different operating conditions, providing both heating and cooling, enabling dual-purpose operation, improving equipment utilization, and achieving better energy savings and economic benefits.

[0109] The above-described technical solution of the present invention has the following beneficial technical effects: The embodiments of this invention redesign the original multi-stage generator-condenser absorption heat pump to accommodate both single and dual-effect operation by adding switching valves and pipelines. In single-effect mode, all generators receive external heat sources, and the refrigerant vapor produced by the concentrated solution enters the corresponding condenser to heat the hot water, resulting in higher-temperature hot water for winter heating, particularly suitable for applications where the heat source is low-pressure steam or exhaust steam. In dual-effect mode, the unit has high energy efficiency and consumes less high-temperature heat sources such as steam or gas, making it suitable for producing chilled water for air conditioning or process use in summer. The switching between single and dual-effect modes matches different operating conditions, providing both heating and cooling, improving equipment utilization, and achieving better energy savings and economic benefits.

[0110] It should be understood that although this specification describes various embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0111] The detailed descriptions listed above are merely specific descriptions of feasible embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-stage absorption heat pump unit, characterized in that, It includes a multi-stage heat pump module, which includes: A first-stage heat conversion module (3) has a first generator, a high-temperature condenser and a high-temperature condenser tube bundle (3-1), and a connecting valve (11) is provided in the pipeline connecting the steam outlet of the first generator and the inlet of the condenser; the first generator is a high-temperature generator. A second-stage heat pump module (2) has a second generator, a low-temperature condenser and a low-temperature condenser tube bundle (2-1), the tube bundle of the second generator is connected to the steam outlet of the first generator to form a refrigerant pipeline; a high-temperature generator refrigerant steam valve (12) is provided in the refrigerant pipeline; the second generator is a low-temperature generator. A heating pipeline (4) includes a first heating pipeline (41) and a second heating pipeline (42); the first heating pipeline (41) is connected to the tube bundle of the first generator; the second heating pipeline (42) is connected to the tube bundle of the second generator; a switching valve is provided in the second heating pipeline (42); and A controller, the output of which is connected to the connecting valve (11), the high-temperature generator refrigerant steam valve (12), and the switching valve; A third-stage heat pump module (1) includes an evaporator and an absorber; the evaporator absorbs heat from a low-temperature heat source through refrigerant water and evaporates it into water vapor, which enters the absorber; a heat conversion solution is attached to the outside of the absorber heat transfer tube bundle (1-1) in the absorber, which absorbs the heat released by the water vapor to heat the cooling water in the absorber heat transfer tube bundle (1-1) in circulation; Hot water pipe (5) is connected to the absorber tube bundle of the third-stage heat pump module (1), the low-temperature condenser tube bundle (2-1) of the second-stage heat pump module (2) and the high-temperature condenser tube bundle (3-1) of the first-stage heat conversion module (3). A series control pipeline is provided between the high-temperature condenser tube bundle (3-1) of the first-stage heat conversion module (3) and the low-temperature condenser tube bundle (2-1) of the second-stage heat pump module (2), connecting the high-temperature condenser tube bundle (3-1) of the first-stage heat conversion module (3) and the low-temperature condenser tube bundle (2-1) of the second-stage heat pump module (2) in series; a second valve (17) is provided at the outlet of the condenser of the second-stage heat pump module (2); and A parallel control pipeline is provided between the high-temperature condenser tube bundle (3-1) of the first-stage heat conversion module (3) and the low-temperature condenser tube bundle (2-1) of the second-stage heat pump module (2) to connect the high-temperature condenser tube bundle (3-1) of the first-stage heat conversion module (3) and the low-temperature condenser tube bundle (2-1) of the second-stage heat pump module (2) in parallel. The cold water pipeline is connected to the evaporator tube bundle of the third-stage heat pump module (1) so that the cold water in the evaporator tube bundle releases heat to the refrigerant water in the evaporator, causing it to evaporate into water vapor, and then enters the absorber of the third-stage heat pump module (1) to be absorbed by the solution. When the setting state is single-effect operation state, the controller sends an opening drive information to the connecting valve (11), a closing drive information to the high-temperature generator refrigerant steam valve (12), and an opening drive information to the switching valve, so that the heat source of the first heating pipeline (41) drives the first stage heat conversion module (3) to heat; so that the heat source of the second heating pipeline (42) drives the second stage heat pump module (2) to heat; When the setting state is the dual-effect operation state, the controller sends a closing drive information to the connecting valve (11), sends an opening drive information to the high-temperature generator refrigerant steam valve (12), and sends a closing drive information to the switching valve, so that after the first heating pipeline (41) heats the tube bundle of the first generator, the first generator generates refrigerant steam under the action of the liquid distribution device; and drives the second-stage heat pump module (2) to cool through the refrigerant steam.

2. The multi-stage absorption heat pump unit according to claim 1, characterized in that, A low-temperature solution heat exchange pipeline is included between the low-temperature generator solution outlet of the second-stage heat pump module (2) and the absorber liquid distribution device (1-3) of the third-stage heat pump module (1). The absorber solution outlet pipeline of the third-stage heat pump module (1) is divided into a first branch and a second branch. The solution in the low-temperature solution heat exchange pipeline exchanges heat with the first branch through the low-temperature solution heat exchanger (8-2); the refrigerant condensate in the output pipeline of the low-temperature generator heat transfer tube bundle (2-2) of the second-stage heat pump module (2) exchanges heat with the second branch through the low-temperature refrigerant condensate-solution heat exchanger (8-3); the solution in the outlet pipeline of the generator solution of the first-stage heat conversion module (3) exchanges heat with the solution after the first and second branches merge through the high-temperature solution heat exchanger (8-1), and is connected to the generator liquid distribution device (3-3) of the first-stage heat conversion module (3). When the setting is in the dual-effect operation state, the absorber solution outlet pipeline of the third-stage heat pump module (1) is connected to the low-temperature generator liquid distribution device (2-3) of the second-stage heat pump module (2) via the high-temperature solution heat exchanger (8-1). When the setting is single-effect operation, the absorber solution outlet pipe of the third-stage heat pump module (1) is connected to the low-temperature generator liquid distribution device (2-3) of the second-stage heat pump module (2) via the high-temperature solution heat exchanger (8-1); or the absorber solution outlet pipe of the third-stage heat pump module (1) is connected to the low-temperature generator liquid distribution device (2-3) of the second-stage heat pump module (2).

3. The multi-stage absorption heat pump unit according to claim 2, characterized in that, After the condenser pipeline of the first-stage heat conversion module (3) is connected to the refrigerant water pipeline of the condensate in the second-stage heat pump module (2), it is connected to the evaporator pipeline of the third-stage heat pump module (1).

4. The multi-stage absorption heat pump unit according to claim 2, characterized in that, The second-stage heat pump module (2) is configured as multi-stage; In dual-effect mode, the refrigerant water in the low-temperature generator heat transfer tube bundle (2-2) of the multi-stage second-stage heat pump module (2) is collected through the manifold and then heats the solution in the low-temperature solution heat exchange pipeline through the low-temperature refrigerant condensate-solution heat exchanger (8-3) to heat the solution in the low-temperature refrigerant condensate-solution heat exchanger (8-3); the manifold is connected to the condensation pipeline in the second-stage heat pump module (2).

5. The multi-stage absorption heat pump unit according to claim 4, characterized in that, A second inlet electric valve (22) is installed at the pipeline inlet of the generator tube bundle in the multi-stage second-stage heat pump module (2).

6. The multi-stage absorption heat pump unit according to claim 1, characterized in that, When the setting state is dual-effect operation state, the controller sends a closing drive information to the first bypass valve (18), the high-temperature condenser tube bundle outlet valve (21) of the high-temperature condenser tube bundle (3-1), and the high-temperature condenser inlet valve (19) of the high-temperature condenser tube bundle (3-1) to close the first bypass valve (18), the high-temperature condenser tube bundle outlet valve (21), and the high-temperature condenser inlet valve (19); wherein, the first bypass valve (18) is provided on the bypass pipeline between the inlet and outlet of the low-temperature condenser tube bundle (2-1); Send an opening drive information to the second bypass valve (20) of the condenser hot water of the first stage heat conversion module (3) so that the hot water is heated in the absorber tube bundle of the third stage heat pump module (1) and the condenser of the second stage heat pump module (2); wherein the second bypass valve (20) is provided on the bypass line between the inlet and outlet of the high temperature condenser tube bundle (3-1); When the setting state is single-effect operation, the controller controls the valve so that after the hot water flows through the absorber tube bundle of the third-stage heat pump module (1), it flows through the low-temperature condenser tube bundle (2-1) of the second-stage heat pump module (2) and the high-temperature condenser tube bundle (3-1) of the first-stage heat conversion module (3).

7. The multi-stage absorption heat pump unit according to claim 5, characterized in that, When the setting state is single-effect operation, the controller sends a closing drive information to the hot water inlet valve (16) of the low-temperature condenser tube bundle (2-1), the second valve (17) at the outlet of the low-temperature condenser tube bundle (2-1), and the second inlet electric valve (22) at the inlet of the low-temperature generator heat transfer tube bundle (2-2) of the second-stage heat pump module (2), and sends an opening drive information to the first bypass valve (18) so that the hot water is heated in the absorber tube bundle of the third-stage heat pump module (1) and the high-temperature condenser tube bundle (3-1) of the multi-stage first-stage heat conversion module (3); wherein, the first bypass valve (18) is set on the bypass pipeline between the inlet and outlet of the low-temperature condenser tube bundle (2-1).

8. The multi-stage absorption heat pump unit according to claim 1, characterized in that, When the setting is single-effect operation, the controller controls the high-pressure steam, high-temperature hot water, gas or high-temperature flue gas pipeline to connect with the first heating pipeline (41); the controller controls the steam or exhaust steam pipeline to connect with the second heating pipeline (42).

9. The multi-stage absorption heat pump unit according to claim 2, characterized in that, When the setting state is the dual-effect operation state, the controller controls the outlet pipe of the second heating pipeline (42) and the heat transfer tube bundle (2-2) of the low temperature generator to be in a vacuum state; When the setting state is single-effect operation state, the controller controls the outlet pipe of the second heating pipeline (42) and the heat transfer tube bundle of the low temperature generator to be in a non-vacuum state.

10. The multi-stage absorption heat pump unit according to claim 1, characterized in that, Also includes: A solution pump (101), disposed between the absorber and generator in the third-stage heat pump module (1) and the first-stage heat conversion module (3) and the second-stage heat pump module (2), provides circulating power from the absorber to the generator; and A refrigerant pump (102) is located between the evaporator housing and the evaporator liquid distribution device in the third-stage heat pump module (1) to provide power for refrigerant liquid distribution.

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