Organic working medium ejector compression combined heat pump heating system and control method

Abstract

The present application relates to a kind of organic working medium injection compression combined heat pump heating system and control method, system includes condenser, first economizer, evaporator, compressor, second economizer, ejector, working medium pump and generator, condenser is connected with the secondary high pressure fluid inlet of first economizer and ejector outlet, condenser is connected with heating terminal equipment and constitutes heating circuit, evaporator is connected with the low pressure fluid inlet of first economizer and secondary high pressure fluid outlet, evaporator is connected with low temperature heat source and constitutes heat recovery circuit, compressor is connected with the medium pressure fluid inlet of second economizer and the low pressure fluid outlet of first economizer, the medium pressure fluid outlet of second economizer is connected with the injection fluid inlet of ejector, working medium pump is connected with the high pressure fluid inlet of second economizer and condenser outlet, generator is connected with the working fluid inlet of ejector and the high pressure fluid outlet of second economizer, it has the advantages of simple structure, safe and reliable;Method has the advantages of simple process, easy to control.

Description

Technical Field

[0001] This invention relates to a heating system, specifically to a composite heat pump heating system based on organic working fluid ejection and compression, and a control method for the system. Background Technology

[0002] Winter heating accounts for a significant proportion of urban energy consumption in northern my country, presenting substantial potential for energy conservation and carbon reduction. Some cities are increasingly utilizing low-grade heat sources such as industrial waste heat, data center waste heat, and shallow geothermal energy, a crucial pathway for energy conservation and carbon reduction in the heating sector. Consequently, heating systems that couple low-temperature (low-grade) heat sources with high-temperature heat sources such as gas-fired boilers or combined heat and power (CHP) systems are gradually gaining wider application. However, existing such coupled heating systems simply connect compression heat pumps in series or parallel with gas-fired boilers or CHP heat sources, failing to fully utilize the working capacity of high-temperature heat sources. This limits further improvement in overall system energy efficiency and results in relatively high heating costs. Summary of the Invention

[0003] The purpose of this invention is to provide an organic working fluid ejector compression composite heat pump heating system and control method. The system has the advantages of simple structure, low cost, and safety and reliability; the method has the advantages of simple process and convenient operation.

[0004] To address the aforementioned technical problems in the prior art, this invention provides an organic working fluid ejector compression composite heat pump heating system, comprising a condenser, a first economizer, an evaporator, a compressor, a second economizer, an ejector, a working fluid pump, and a generator. The inlet and outlet of the condenser are connected via pipelines to the secondary high-pressure fluid inlet of the first economizer and the outlet of the ejector, respectively. The condenser is also connected via pipelines to heating terminal equipment to form a heating circuit. The inlet and outlet of the evaporator are connected via pipelines to the low-pressure fluid inlet and the secondary high-pressure fluid outlet of the first economizer, respectively. The evaporator is also connected via pipelines to a low-temperature heat source to form a heat recovery circuit. The compressor... The inlet and outlet of the generator are connected to the medium-pressure fluid inlet of the second economizer and the low-pressure fluid outlet of the first economizer via pipelines. The medium-pressure fluid outlet of the second economizer is connected to the ejector fluid inlet via pipelines. The inlet and outlet of the working fluid pump are connected to the high-pressure fluid inlet of the second economizer and the outlet of the condenser via pipelines. The inlet and outlet of the generator are connected to the working fluid inlet of the ejector and the high-pressure fluid outlet of the second economizer via pipelines. An electronic expansion valve is installed on the pipeline between the working fluid inlet of the evaporator and the first economizer. The low-temperature heat source refers to industrial waste heat, data center waste heat, ground source, water source or solar energy.

[0005] Furthermore, the present invention provides an organic working fluid ejector compression composite heat pump heating system, wherein a first electric valve is provided on the pipeline between the condenser and the working fluid pump, and a second electric valve is provided on the pipeline between the second economizer and the working fluid pump.

[0006] Furthermore, the present invention provides an organic working fluid ejector compression composite heat pump heating system, wherein the compressor is an electrically driven compressor, and the heat source of the generator is a high-temperature heat source, which comes from a gas burner, a gas boiler, a high-temperature hot water heat exchanger, or a steam-water heat exchanger.

[0007] Furthermore, the present invention provides an organic working fluid ejector compression composite heat pump heating system, wherein the condenser is provided in two or more units connected in series.

[0008] Furthermore, the present invention provides an organic working fluid ejector compression composite heat pump heating system, wherein the evaporator is provided in two or more units connected in series.

[0009] Furthermore, the present invention provides an organic working fluid ejector compression composite heat pump heating system, wherein the generator is provided in two or more units connected in series.

[0010] Furthermore, the present invention provides an organic working fluid ejector compression composite heat pump heating system, wherein the organic working fluid is R290.

[0011] Based on the same concept, the present invention also provides a control method for the above-mentioned heating system, comprising the following steps: S1. When the system is running in combined heat pump mode, start the compressor, working fluid pump and generator, and open the first electric valve and the second electric valve. S2. The organic working fluid circulates in the compression heat pump circuit and the absorption heat pump circuit. The compression heat pump circuit is a circuit consisting of a condenser, a first economizer, an electronic expansion valve, an evaporator, a compressor, a second economizer, and an ejector connected in sequence. The absorption heat pump circuit is a circuit consisting of a condenser, a first electric valve, a working fluid pump, a second electric valve, a second economizer, a generator, and an ejector connected in sequence. S3. In the heating circuit, the water exchanges heat with the organic working fluid in the condenser. The organic working fluid releases heat, and the water in the heating circuit absorbs heat and transfers the heat to the heating terminal equipment. In the heat recovery circuit, the water exchanges heat with the organic working fluid in the evaporator. The organic working fluid absorbs heat, and the water in the heat recovery circuit releases heat and flows back to the low-temperature heat source.

[0012] Furthermore, the control method for a heating system of the present invention further includes the following steps: S4. When the system is running in compression heat pump mode, start the compressor, stop the working fluid pump and generator, and close the first electric valve and the second electric valve. S5. The organic working fluid circulates in the compression heat pump circuit. The water in the heating circuit absorbs heat in the condenser and then returns to the heating terminal equipment to release heat. The water in the heat recovery circuit releases heat in the evaporator and then returns to the low-temperature heat source to absorb heat.

[0013] Compared with existing technologies, the organic working fluid ejector compression composite heat pump heating system and control method of this invention have the following advantages: This invention, by setting up a condenser, a first economizer, an evaporator, a compressor, a second economizer, an ejector, a working fluid pump, and a generator, connects the inlet and outlet of the condenser to the secondary high-pressure fluid inlet of the first economizer and the outlet of the ejector via pipelines, and connects the condenser to the heating terminal equipment via pipelines to form a heating loop. Similarly, the inlet and outlet of the evaporator are connected to the low-pressure fluid inlet and the secondary high-pressure fluid outlet of the first economizer via pipelines, and the evaporator is connected to a low-temperature heat source via pipelines to form a heat recovery loop. The compressor's inlet and outlet are connected to the medium-pressure fluid inlet of the second economizer and the low-pressure fluid outlet of the first economizer via pipelines. The medium-pressure fluid outlet of the second economizer is connected to the ejector's inlet via pipelines. The working fluid pump's inlet and outlet are connected to the high-pressure fluid inlet of the second economizer and the condenser's outlet via pipelines. The generator's inlet and outlet are connected to the working fluid inlet of the ejector and the high-pressure fluid outlet of the second economizer via pipelines. An electronic expansion valve is installed on the pipeline between the evaporator's working fluid inlet and the first economizer. The low-temperature heat source refers to industrial waste heat, data center waste heat, ground source, water source, or solar energy. This constitutes a simple, low-cost, safe, and reliable organic working fluid ejector compression composite heat pump heating system. During system operation, the high-temperature, high-pressure gaseous working fluid enters the condenser and releases heat, changing from sub-high-pressure saturated steam to saturated liquid. This process is used to heat the water in the heating loop. After being heated, the water in the heating loop returns to the heating terminal equipment through circulation. A portion of the working fluid from the condenser outlet, which is also a saturated liquid, is subcooled by the first economizer and then expands through the electronic expansion valve to become a low-temperature, low-pressure unsaturated liquid. This low-temperature, low-pressure unsaturated liquid then enters the evaporator, where the working fluid absorbs heat and evaporates to form low-temperature, low-pressure saturated steam. This process is used to recover heat from the low-temperature heat source. The water in the heat recovery loop releases heat and returns to the low-temperature heat source through circulation. The low-temperature, low-pressure saturated steam then enters the first... The economizer exchanges heat with the working fluid from the condenser outlet to achieve superheating, forming low-temperature, low-pressure superheated steam. This low-temperature, low-pressure superheated steam then enters the compressor and isentropically pressurizes to form medium-pressure superheated steam. The medium-pressure superheated steam then enters the second economizer to exchange heat with the working fluid from the working fluid pump outlet, forming medium-pressure ejector fluid, which enters the ejector. Another portion of the working fluid, which is a saturated liquid from the condenser outlet, enters the working fluid pump and isentropically pressurizes to form a subcooled liquid. The subcooled liquid enters the second economizer for preheating, then enters the generator for further heating to form high-temperature, high-pressure saturated steam. This steam then enters the ejector to form the working fluid used to eject the medium-pressure fluid. Through ejection by the ejector, the high-temperature, high-pressure saturated steam mixes with the medium-pressure superheated steam to form sub-high-pressure steam, which then enters the condenser to release heat, thus completing a full cycle. This cycle repeats continuously to provide heating and energy.This invention improves the energy efficiency of compression heat pump systems in scenarios involving coupled low-temperature and high-temperature heat sources by establishing a composite heat pump heating system based on organic working fluid compression and ejection. The working fluid, which releases heat in the evaporator, is heated to higher temperature and pressure by a compressor to form ejected steam. The working fluid is then further heated to higher temperature and pressure by a working fluid pump and generator to prepare working steam for ejection. An ejector further increases the working fluid pressure. Compared to traditional compression heat pump systems, this method fully utilizes the work capacity of the high-temperature heat source (generator's heat source), effectively reducing the compressor exhaust pressure, decreasing compressor workload, improving system energy efficiency, and lowering heating costs. The control method for this heating system provided by this invention is simple in process and easy to operate.

[0014] The following detailed description, in conjunction with the accompanying drawings, illustrates a composite heat pump heating system and control method based on an organic working fluid ejector compression. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of an organic working fluid ejector compression composite heat pump heating system according to the present invention. Detailed Implementation

[0016] First, it should be noted that the directional terms such as up, down, left, right, front, and back used in this invention are merely descriptions based on the accompanying drawings for ease of understanding, and are not intended to limit the technical solution or the scope of protection claimed in this invention.

[0017] like Figure 1The present invention illustrates a specific embodiment of an organic working fluid ejector compression composite heat pump heating system, comprising a condenser 1, a first economizer 2, an evaporator 3, a compressor 4, a second economizer 5, an ejector 6, a working fluid pump 7, and a generator 8. Connect the inlet and outlet of condenser 1 to the secondary high-pressure fluid inlet of first economizer 2 and the outlet of ejector 6 via pipelines, and connect condenser 1 to heating terminal equipment via pipelines to form a heating circuit; connect the inlet and outlet of evaporator 3 to the low-pressure fluid inlet and secondary high-pressure fluid outlet of first economizer 2 via pipelines, and connect evaporator 3 to a low-temperature heat source via pipelines to form a heat recovery circuit; connect the inlet and outlet of compressor 4 to the medium-pressure fluid inlet of second economizer 5 and the low-pressure fluid outlet of first economizer 2 via pipelines, and connect the medium-pressure fluid outlet of second economizer 5 to the ejected fluid inlet of ejector 6 via pipelines; connect the inlet and outlet of working fluid pump 7 to the high-pressure fluid inlet of second economizer 5 and the outlet of condenser 1 via pipelines; connect the inlet and outlet of generator 8 to the working fluid inlet of ejector 6 and the high-pressure fluid outlet of second economizer 5 via pipelines. Among them, an electronic expansion valve 9 is installed on the pipeline between the working fluid inlet of the evaporator 3 and the first economizer 2. The low-temperature heat source refers to industrial waste heat, data center waste heat, ground source, water source or solar energy.

[0018] The above configuration constitutes a simple, low-cost, safe, and reliable organic working fluid ejector compression composite heat pump heating system. During system operation, the high-temperature, high-pressure gaseous working fluid enters condenser 1 and releases heat, transforming from sub-high-pressure saturated steam to saturated liquid. This process heats the water in the heating loop, which, after being heated, circulates back to the terminal heating equipment. A portion of the working fluid from the condenser 1 outlet, now in saturated liquid form, is subcooled by the first economizer 2 and then expands under reduced pressure through the electronic expansion valve 9, becoming a low-temperature, low-pressure unsaturated liquid. This unsaturated liquid then enters evaporator 3, where it absorbs heat and evaporates to form low-temperature, low-pressure saturated steam. This process recovers heat from the low-temperature heat source. The water in the heat recovery loop releases heat and circulates back to the low-temperature heat source. The low-temperature, low-pressure saturated steam then enters the first economizer 2 to exchange heat with the working fluid from the condenser 1 outlet, achieving superheating. Low-temperature, low-pressure superheated steam is formed, then enters compressor 4 and isentropically pressurized to form medium-pressure superheated steam. This medium-pressure superheated steam then enters the second economizer 5 and exchanges heat with the working fluid from the outlet of working fluid pump 7, forming a medium-pressure ejector fluid that enters the ejector. Another portion of the working fluid, which is a saturated liquid from the outlet of condenser 1, enters working fluid pump 7 and isentropically pressurized to form a subcooled liquid. This subcooled liquid enters the second economizer 5 for preheating, then enters generator 8 for further heating to form high-temperature, high-pressure saturated steam. This steam then enters ejector 6 to form the working fluid used to eject the medium-pressure fluid. Through ejection by ejector 6, the high-temperature, high-pressure saturated steam mixes with the medium-pressure superheated steam to form sub-high-pressure steam, which then enters the condenser to release heat, thus completing a full cycle. This continuous cycle provides heat and energy. This invention improves the energy efficiency of compression heat pump systems in scenarios where low-temperature and high-temperature heat sources are coupled for heating by setting up a composite heat pump heating system based on organic working fluid compression and ejection. The working fluid that releases heat in the evaporator is heated to higher temperature and pressure by the compressor to form ejected steam. The working fluid temperature and pressure are further increased by the working fluid pump and generator to prepare working steam for ejection. The working fluid pressure is further increased by the ejector. Compared with traditional compression heat pump systems, this method has the advantage of fully utilizing the work capacity of the high-temperature heat source (the heat source of the generator), effectively reducing the compression exhaust pressure, reducing the workload of the compressor, improving system energy efficiency, and reducing heating costs. It should be noted that the condenser, economizer, evaporator, compressor, ejector and generator in this application are all existing equipment in the art, and their structure, principle and connection method are well known to those skilled in the art. Among them, the compressor is an electrically driven compressor, which can realize electric drive operation and improve the convenience of control. The heat source of the generator is a high-temperature heat source, which can be a gas burner, a gas boiler, a high-temperature hot water heat exchanger or a steam-water heat exchanger. The high-temperature hot water in the high-temperature hot water heat exchanger or the high-temperature steam in the steam-water heat exchanger can come from various sources such as cogeneration.It should also be noted that the present invention typically uses R290 as the organic working medium, but is not limited to R290; other organic working media with equivalent functions may also be used.

[0019] As an optimization, this specific embodiment includes a first electric valve 10 on the pipeline between the condenser 1 and the working fluid pump 7, and a second electric valve 11 on the pipeline between the second economizer 5 and the working fluid pump 7. This arrangement utilizes the pipeline shut-off function of the first electric valve 10 and the second electric valve 11 to improve the system's adaptability and flexibility, allowing the system to switch between a combined heat pump mode and a compression heat pump mode to meet the requirements of high and low heating loads. The combined heat pump mode refers to the operating mode where all equipment in the system is working, while the compression heat pump mode refers to the mode where the first electric valve 10 and the second electric valve 11 are closed, and the working fluid pump 7 and the generator 8 are stopped. Under low heating load conditions, this system utilizes a higher proportion of heat from the low-temperature heat source than the lithium bromide absorption heat pump system; under high heating load conditions, this system can more fully utilize the work capacity of the high-temperature heat source, improving the energy efficiency of the compression heat pump. In practical applications, depending on actual needs, the present invention can connect two or more condensers 1, evaporators 3, and generators 8 in series.

[0020] Based on the same concept, the present invention also provides a control method for the heating system, comprising the following steps: S1. When the system operates in combined heat pump mode, start compressor 4, working fluid pump 7, and generator 8, and open the first electric valve 10 and the second electric valve 11. At this time, the heat provided by the system can meet the requirements of high heating load.

[0021] S2. The organic working fluid circulates in the compression heat pump circuit and the absorption heat pump circuit. The compression heat pump circuit is a circuit consisting of the condenser 1, the first economizer 2, the electronic expansion valve 9, the evaporator 3, the first economizer 2, the compressor 4, the second economizer 5 and the ejector 6 connected in sequence. The absorption heat pump circuit is a circuit consisting of the condenser 1, the first electric valve 10, the working fluid pump 7, the second electric valve 11, the second economizer 5, the generator 8 and the ejector 6 connected in sequence.

[0022] S3. In the heating circuit, the water exchanges heat with the organic working fluid in the condenser 1. The organic working fluid releases heat, and the water in the heating circuit absorbs heat and transfers the heat to the heating terminal equipment. In the heat recovery circuit, the water exchanges heat with the organic working fluid in the evaporator 3. The organic working fluid absorbs heat, and the water in the heat recovery circuit releases heat and flows back to the low-temperature heat source.

[0023] S4. When the system is running in compression heat pump mode, start compressor 4, stop working fluid pump 7 and generator 8, and close the first electric valve 10 and the second electric valve 11. At this time, the heat provided by the system can meet the requirements of low heating load.

[0024] S5. The organic working fluid circulates in the compression heat pump circuit. The water in the heating circuit absorbs heat in the condenser 1 and then returns to the heating terminal equipment to release heat. The water in the heat recovery circuit releases heat in the evaporator 3 and then returns to the low-temperature heat source to absorb heat.

[0025] To aid technical personnel in understanding, the functions of the first and second economizers in this invention are briefly explained below: The purpose of setting up the first and second economizers is to increase the superheat and subcooling of the organic working fluid during the circulation process, thereby improving the system's operating efficiency. The condenser outlet working fluid temperature is the evaporator design temperature, close to the supply water temperature of the heating network (heating circuit), approximately 60°C. The evaporator outlet working fluid temperature is the evaporator design temperature, close to the circulating water temperature of the low-temperature heat source (heat recovery circuit), approximately 5°C. The low-temperature working fluid at the evaporator outlet and the medium-temperature working fluid at the condenser outlet exchange heat through the first economizer, providing subcooling to the condenser outlet working fluid. This increases the amount of heat absorbed by the working fluid after depressurization and expansion via the electronic expansion valve before entering the evaporator, enhancing the heat pump system's utilization of the low-temperature heat source. The working fluid undergoes an isentropic pressurization process as a saturated liquid through the working fluid pump, with minimal temperature change, close to the evaporator outlet temperature of approximately 60°C. The working fluid then undergoes an isentropic pressurization process as superheated steam through the compressor, resulting in a rapid temperature increase, reaching over 90°C. The high-temperature steam at the compressor outlet and the medium-temperature liquid at the working fluid pump outlet exchange heat through a second economizer, preheating the subcooled liquid at the pump outlet. This reduces the heat absorbed by the working fluid upon entering the generator, decreases the system's heat demand from the high-temperature heat source, and increases the proportion of heating from the low-temperature heat source.

[0026] The organic working fluid in this invention can be adjusted according to the application scenario and the temperature of the low-temperature heat source, and can be a single-component organic working fluid or a mixture of organic working fluids. The composite heat pump heating system provided by this invention can be equipped with two or more generators connected in series, with the high-temperature heat source passing through each generator sequentially to more thoroughly absorb the heat from the high-temperature heat source. Similarly, two or more condensers connected in series can be installed, with the heating circuit passing through each condenser sequentially to ensure more complete heating of the water in the heating circuit. Likewise, two or more evaporators connected in series can be installed, with the heat recovery circuit passing through each evaporator sequentially to ensure more complete heat recovery from the low-temperature heat source. Compression heat pumps have a high compression ratio, and the evaporator design temperature can reach 5°C or below, enabling full recovery and utilization of heat from low-temperature heat sources such as industrial waste heat, data center waste heat, ground source, water source, and solar energy. By utilizing the coupled high-temperature heat source, it is a more efficient waste heat utilization method. At the same time, the ejector has a simple structure, small size, and low cost, making the composite heat pump heating system provided by this invention compact and cost-effective. It should be noted that the working medium and organic working medium in this document should be understood as the same concept.

[0027] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Various modifications made by those skilled in the art based on the technical solutions of the present invention without departing from the design concept of the present invention should fall within the scope of protection defined by the claims of the present invention.

Claims

1. An organic working fluid ejector compression composite heat pump heating system, characterized in that, The system includes a condenser (1), a first economizer (2), an evaporator (3), a compressor (4), a second economizer (5), an ejector (6), a working fluid pump (7), and a generator (8). The inlet and outlet of the condenser (1) are connected to the sub-high pressure fluid inlet of the first economizer (2) and the outlet of the ejector (6) via pipelines. The condenser (1) is also connected to the heating terminal equipment via pipelines to form a heating circuit. The inlet and outlet of the evaporator (3) are connected to the low pressure fluid inlet and the sub-high pressure fluid outlet of the first economizer (2) via pipelines. The evaporator (3) is also connected to the low temperature heat exchanger via pipelines. The source connection forms a heat recovery loop. The inlet and outlet of the compressor (4) are connected to the medium-pressure fluid inlet of the second economizer (5) and the low-pressure fluid outlet of the first economizer (2) through pipelines. The medium-pressure fluid outlet of the second economizer (5) is connected to the ejector (6) through pipelines. The inlet and outlet of the working fluid pump (7) are connected to the high-pressure fluid inlet of the second economizer (5) and the outlet of the condenser (1) through pipelines. The inlet and outlet of the generator (8) are connected to the working fluid inlet of the ejector (6) and the high-pressure fluid outlet of the second economizer (5) through pipelines. An electronic expansion valve (9) is provided on the pipeline between the working fluid inlet of the evaporator (3) and the first economizer (2). The low-temperature heat source refers to industrial waste heat, data center waste heat, ground source, water source or solar energy.

2. The organic working fluid ejector compression composite heat pump heating system according to claim 1, characterized in that, A first electric valve (10) is provided on the pipeline between the condenser (1) and the working fluid pump (7), and a second electric valve (11) is provided on the pipeline between the second economizer (5) and the working fluid pump (7).

3. The organic working fluid ejector compression composite heat pump heating system according to claim 2, characterized in that, The compressor (4) is an electrically driven compressor, and the heat source of the generator (8) is a high-temperature heat source, which comes from a gas burner, a gas boiler, a high-temperature hot water heat exchanger or a steam-water heat exchanger.

4. The organic working fluid ejector compression composite heat pump heating system according to claim 3, characterized in that, The condenser (1) has two or more units connected in series.

5. The organic working fluid ejector compression composite heat pump heating system according to claim 3, characterized in that, The evaporator (3) has two or more units connected in series.

6. The organic working fluid ejector compression composite heat pump heating system according to claim 3, characterized in that, The generator (8) has two or more units connected in series.

7. The organic working fluid ejector compression composite heat pump heating system according to claim 3, characterized in that, The organic working fluid is R290.

8. A control method for the heating system according to claim 3, characterized in that, Includes the following steps: S1. When the system is running in the combined heat pump mode, start the compressor (4), working fluid pump (7) and generator (8), and open the first electric valve (10) and the second electric valve (11). S2. The organic working fluid circulates in the compression heat pump circuit and the absorption heat pump circuit. The compression heat pump circuit is a circuit consisting of the condenser (1), the first economizer (2), the electronic expansion valve (9), the evaporator (3), the first economizer (2), the compressor (4), the second economizer (5), and the ejector (6) connected in sequence. The absorption heat pump circuit is a circuit consisting of the condenser (1), the first electric valve (10), the working fluid pump (7), the second electric valve (11), the second economizer (5), the generator (8), and the ejector (6) connected in sequence. S3. The water in the heating circuit exchanges heat with the organic working medium in the condenser (1). The organic working medium releases heat, and the water in the heating circuit absorbs heat and transfers the heat to the heating terminal equipment. The water in the heat recovery circuit exchanges heat with the organic working medium in the evaporator (3). The organic working medium absorbs heat, and the water in the heat recovery circuit releases heat and flows back to the low-temperature heat source.

9. The control method for a heating system according to claim 8, characterized in that, It also includes the following steps: S4. When the system is running in compression heat pump mode, start the compressor (4), stop the working fluid pump (7) and generator (8), and close the first electric valve (10) and the second electric valve (11). S5. The organic working fluid circulates in the compression heat pump circuit. The water in the heating circuit absorbs heat in the condenser (1) and then returns to the heating terminal equipment to release heat. The water in the heat recovery circuit releases heat in the evaporator (3) and then returns to the low-temperature heat source to absorb heat.

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