Multi-heat-source composite heat supply system

Abstract

The invention discloses a multi-heat-source composite heat supply system which comprises a water source heat pump. The air source heat pump provides a low-temperature heat source for the water source heat pump; the environment temperature sensor is used for detecting the temperature of the environment where the multi-heat-source composite heat supply system is located; the control unit is used for controlling the first control valve, the second control valve, the third control valve, the air source heat pump and the water source heat pump to enter a direct heat supply mode or a coupling heat supply mode based on the environment temperature or the water temperature required by a user; and under the coupling heat supply mode, based on the energy efficiency ratio of the air source heat pump, the energy efficiency ratio of the water source heat pump, the total energy efficiency ratio of the system, the environment temperature and the water temperature required by the user target, the coupling heat supply mode is controlled to be kept or switched to the direct heat supply mode. Efficient heating of a user is achieved.

Description

Technical Field

[0001] This invention relates to the field of heating equipment technology, and in particular to a multi-heat source composite heating system. Background Technology

[0002] An air source heat pump, also known as an air-source water heater, works by absorbing low-temperature heat from the air, vaporizing it with a refrigerant, compressing it, and then transferring the resulting high-temperature heat to the water via a heat exchanger. Air source heat pumps are characterized by high efficiency, energy saving, and high energy utilization.

[0003] However, due to the influence of refrigerant characteristics, technical level, and manufacturing cost, the outlet water temperature of air source heat pumps cannot be too high, and the maximum is often only around 60℃, which is difficult to meet the market demand for high water temperature.

[0004] Ground source heat pumps utilize low-grade heat energy resources formed by absorbing solar and geothermal energy from shallow water sources on the Earth's surface, such as groundwater, rivers, and lakes. Employing the heat pump principle, they transfer low-grade heat energy to higher-grade heat energy through a small input of high-grade electricity. Ground source heat pumps are highly efficient and can achieve both cooling and heating with a small amount of electrical energy input, and their development has been rapid in recent years.

[0005] Traditional air source heat pump heating solutions come in two forms: coupled air source heat pump and water source heat pump heating, and direct air source heat pump supply. The coupled solution is suitable when the hot water temperature differs significantly from the ambient temperature (generally, the hot water temperature is more than 50°C higher than the ambient temperature), while direct air source heat pump supply is suitable for situations where the hot water temperature is not significantly different from the ambient temperature. However, during the heating season, ambient temperature fluctuates considerably; therefore, both solutions have their limitations, and relying on a single heating solution for the entire winter does not achieve optimal energy efficiency.

[0006] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Summary of the Invention

[0007] To address the problems mentioned in the background art, this invention provides a multi-heat source composite heating system that considers ambient temperature and user target water temperature requirements. It switches between a direct heating mode using an air source heat pump and a coupled heating mode using both an air source heat pump and a water source heat pump. Furthermore, in the coupled heating mode, based on the energy efficiency ratio of the air source heat pump, the energy efficiency ratio of the water source heat pump, and the overall system energy efficiency ratio, it switches to a direct heating mode or maintains the coupled heating mode, thereby improving system energy efficiency while meeting user heating needs.

[0008] To achieve the above-mentioned objectives, the present invention employs the following technical solution: Some embodiments of this application provide a multi-heat source composite heating system, including: Water source heat pump; The first control valve is used to control whether water from the water collector is supplied to the condenser side of the water source heat pump; An air source heat pump that provides a low-temperature heat source to the water source heat pump; The hot water storage tank has its inlet end connected between the third control valve and the outlet end of the air source heat pump on the condenser side, and its outlet end connected to the inlet end of the water source heat pump on the evaporator side. The second control valve is used to control whether water from the water collector is supplied to the condenser side of the air source heat pump; The water distributor is connected to the condenser-side outlet of the water source heat pump. The third control valve is used to control the supply of water after heat exchange on the condenser side of the air source heat pump to the water distributor or the evaporator side of the water source heat pump. An ambient temperature sensor is used to detect the ambient temperature of the multi-heat source composite heating system. A control unit is used to control whether water is supplied to the multi-heat source composite heating system through the water collector, and the control unit is communicatively connected to both the air source heat pump and the water source heat pump. The control unit controls the first control valve, the second control valve, the third control valve, the air source heat pump, and the water source heat pump based on the ambient temperature or the user's required water temperature, so as to enter the direct heating mode of the air source heat pump or the coupled heating mode of the air source heat pump and the water source heat pump. In the coupled heating mode, based on the energy efficiency ratio of the air source heat pump, the energy efficiency ratio of the water source heat pump, the total energy efficiency ratio of the system, the ambient temperature, and the user's target water temperature requirement, the system controls and maintains the coupled heating mode or switches to the direct heating mode.

[0009] The multi-heat source composite heating system involved in this application includes water source heat pumps and air source heat pumps. When the ambient temperature is low or the user needs high-temperature hot water, a coupled heating mode of water source heat pumps and air source heat pumps is adopted. When the ambient temperature is high or the user does not need high-temperature hot water, the air source heat pump has high energy efficiency. At this time, the direct heating mode of air source heat pumps is adopted, which can save energy while meeting the user's heating needs.

[0010] In the coupled heating mode, the energy efficiency ratio of the air source heat pump, the energy efficiency ratio of the water source heat pump, and the total energy efficiency ratio of the system are considered. The system controls the switching between the direct heating mode of the air source heat pump and the coupled heating mode of the air source heat pump and the water source heat pump to achieve efficient heating.

[0011] In some embodiments of this application, the multi-heat source composite heating system further includes: An intermediate circulating water pump is installed in the circulation loop where the air source heat pump provides a low-temperature heat source to the water source heat pump; A buffer tank, the water inlet of which is connected to the water outlet on the evaporator side of the water source heat pump, and the water outlet of which is connected to the water inlet on the condenser side of the air source heat pump; The control unit controls the opening and closing of the intermediate circulating water pump based on the opening and closing of the air source heat pump.

[0012] In some embodiments of this application, the control unit controls the on / off state of the first control valve, the second control valve, and the third control valve based on the ambient temperature or the user's required water temperature, specifically as follows: When the ambient temperature decreases or the user requests a higher water temperature, the control unit controls the first control valve to open, the second control valve, the third control valve, the air source heat pump and the water source heat pump to start. When the ambient temperature rises or the user requests a lower water temperature, the control unit controls the first control valve to disconnect, the second control valve and the third control valve to open, the air source heat pump to start, and the water source heat pump to disconnect.

[0013] This application switches between direct heating mode and coupled heating mode based on changes in ambient temperature or changes in user-demanded water temperature.

[0014] In some embodiments of this application, under coupled heating mode, based on the COP1 of the air source heat pump, the COP2 of the water source heat pump, the overall system COP, the ambient temperature, and the user's target water temperature requirement, the system controls the maintenance of coupled heating mode or switches to direct heating mode, specifically: S1: The air source heat pump is turned on with the target temperature as the target temperature, and the water source heat pump is turned on with the user's target water temperature as the user's target water temperature, and then proceeds to S2. S2: Determine whether the user's requested water temperature meets the user's target water temperature. If yes, proceed to S3; otherwise, return to S2. S3: Increase the target water temperature of the air source heat pump and proceed to S4; S4: Determine if COP1 is greater than COP. If yes, proceed to S5; otherwise, proceed to S8. S5: Switch to direct heating mode and proceed to S6; S6: Determine if the ambient temperature has decreased. If yes, proceed to S7; otherwise, determine if the user's target water temperature has increased. If yes, proceed to S7; otherwise, return to S6. S7: If COP1 reaches the lower limit of the energy efficiency ratio of the water source heat pump when switching to direct heating mode, start the water source heat pump with the current user target water temperature and return to S2. S8: Determine whether the system's overall energy efficiency ratio (COP) has increased. If yes, proceed to S9; otherwise, proceed to S93. S9: Determine whether the system's overall energy efficiency ratio (COP) has reached its energy efficiency peak. If yes, proceed to S91; otherwise, return to S3. S91: Determine if the ambient temperature has increased. If yes, return to S3. Otherwise, determine if the ambient temperature has decreased. If yes, proceed to S93. If no, proceed to S92. S92: Determine whether the user's target water temperature has decreased. If yes, return to S3. Otherwise, determine whether the user's target water temperature has increased. If yes, proceed to S93. If no, return to S91. S93: Reduce the target water temperature of the air source heat pump and proceed to S94; S94: Determine whether the system's overall energy efficiency ratio (COP) has increased. If yes, proceed to S95; otherwise, proceed to S91. S95: Determine whether the system's overall energy efficiency ratio (COP) has reached its energy efficiency peak. If yes, proceed to S91; otherwise, return to S93.

[0015] In some embodiments of this application, after raising the target water temperature of the air source heat pump for a period of time in S3, it is then determined whether COP1 is greater than COP in S4. After lowering the target water temperature of the air source heat pump for a period of time in S93, it is then determined in S94 whether the system's total energy efficiency ratio (COP) has increased.

[0016] The multi-heat source composite heating system involved in this application determines whether to switch to direct heating mode by judging the energy efficiency ratio of the air source heat pump in coupled heating mode. In coupled heating mode, the total energy efficiency ratio (COP) of the system is obtained by changing the target water temperature of the air source heat pump to meet the system's high-efficiency coupled heating needs. In high-efficiency heating mode, the ambient temperature or the user's target hot water temperature is judged to ensure high-efficiency heating.

[0017] In some embodiments of this application, the air source heat pump serves as the low-temperature water source for the water source heat pump, and the method for obtaining the target activation temperature is as follows: Under the current ambient temperature and the user's target water temperature, when the heating capacity of the air source heat pump and the heat output of the water source heat pump are balanced, the outlet water temperature of the hot water storage tank is determined. Set the determined outlet water temperature of the hot water storage tank as the target opening temperature.

[0018] In some embodiments of this application, the multi-heat source composite heating system further includes: A system circulating water pump is installed on the water supply pipeline of the water collector, and the system circulating water pump is connected to the control unit.

[0019] The control unit involved in this application controls the opening and closing of the system's circulating water pump, thereby supplying water from the water collector to the air source heat pump and / or water source heat pump.

[0020] This application also relates to a multi-heat source composite heating system, comprising: Water source heat pump; The first control valve is used to control whether water from the water collector is supplied to the condenser side of the water source heat pump; An air source heat pump that provides a low-temperature heat source to the water source heat pump; The hot water storage tank has its inlet end connected between the third control valve and the outlet end of the air source heat pump on the condenser side, and its outlet end connected to the inlet end of the water source heat pump on the evaporator side. The second control valve is used to control whether water from the water collector is supplied to the condenser side of the air source heat pump; The water distributor is connected to the condenser-side outlet of the water source heat pump. The third control valve is used to control the supply of water after heat exchange on the condenser side of the air source heat pump to the water distributor or the evaporator side of the water source heat pump. An ambient temperature sensor is used to detect the ambient temperature of the multi-heat source composite heating system. A boiler, which is arranged in parallel with the water source heat pump; The fourth control valve is used to control whether water from the water collector is supplied to the boiler; The control unit is used to control whether water is supplied to the multi-heat source composite heating system through the water collector, and the control unit is communicatively connected to the air source heat pump, the water source heat pump and the boiler. The control unit controls the first control valve, the second control valve, the third control valve, the air source heat pump, and the water source heat pump based on the ambient temperature or the user's required water temperature, so as to enter the direct heating mode of the air source heat pump or the coupled heating mode of the air source heat pump and the water source heat pump. In the coupled heating mode, based on the energy efficiency ratio of the air source heat pump, the energy efficiency ratio of the water source heat pump, and the total energy efficiency ratio of the system, the system is controlled to maintain the coupled heating mode or switch to the direct heating mode. When both the air source heat pump and the water source heat pump are operating at full load and still cannot meet the user's heating needs, the control unit then controls the fourth control valve to open and controls the boiler to start.

[0021] The multiple heat sources involved in this application include air source heat pumps, water source heat pumps, and boilers. When the heating demand of users cannot be met even when both air source heat pumps and water source heat pumps are coupled at full load as described above, a boiler is then introduced.

[0022] The combined use of air source heat pumps, water source heat pumps, and boilers increases heating capacity and meets users' heating needs.

[0023] In some embodiments of this application, the control unit monitors the user's heating demand. If the user's heating demand decreases, the control unit gradually controls the reduction of the boiler's power or intermittently turns the boiler on to reduce the boiler's power consumption.

[0024] Other features and advantages of the present invention will become clearer after reading the detailed embodiments of the invention in conjunction with the accompanying drawings. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of an embodiment of the multi-heat source composite heating system proposed in this application; Figure 2 This is a control flowchart of the multi-heat source composite heating system embodiment proposed in this application when the heating mode is initially coupled; Figure 3 This is a schematic diagram of an embodiment of the multi-heat source composite heating system proposed in this application, wherein the dashed line shows the water flow direction in the coupled heating mode; Figure 4 This is a control flowchart of the multi-heat source composite heating system embodiment proposed in this application when starting the direct heating mode; Figure 5 This is a schematic diagram of an embodiment of the multi-heat source composite heating system proposed in this application, wherein the dashed line indicates the water flow direction in the direct heating mode; Figure 6 This is a control flowchart of the multi-heat source composite heating system embodiment proposed in this application after entering the coupled heating mode; Figure 7 The performance curves of the heating capacity of the air source heat pump, the heating capacity of the water source heat pump, and the heat extraction of the water source heat pump as the temperature inside the hot water storage tank changes in the multi-heat source composite heating system embodiment proposed in this application are shown. Figure 8The curves showing the changes in the COP1 of the air source heat pump and the COP2 of the water source heat pump as the temperature inside the hot water storage tank changes in the multi-heat source composite heating system embodiment proposed in this application are shown. Figure 9 This is a control flowchart of the multi-heat source composite heating system embodiment proposed in this application when entering the combined heating mode; Figure 10 This is a schematic diagram of an embodiment of the multi-heat source composite heating system proposed in this application, wherein the dashed line shows the water flow direction when the air source heat pump, water source heat pump and boiler are used for combined heating; Figure label: 110. Air source heat pump; 120. Second control valve; 130. Third control valve; 140. Hot water storage tank; 150. Intermediate circulating water pump; 160. Buffer tank; 210. Water source heat pump; 220. First control valve; 310. Water collector; 320. System circulating water pump; 410. Water distributor; 500. Control unit; 600. Ambient temperature sensor; 710. Boiler; 720. Fourth control valve. Detailed Implementation

[0027] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0029] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0030] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0031] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0032] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0033] Working principle of air source heat pump An air source heat pump, also known as an air source heat pump water heater, transfers heat from the air to the water using a refrigerant. Traditional electric and gas water heaters obtain heat energy by consuming gas and electricity, while air source heat pumps heat water by absorbing heat from the air. They can absorb about three times the amount of heat energy to heat water while consuming the same amount of electricity.

[0034] An air source heat pump consists of four main components: an evaporator, a compressor, a condenser, and a throttling device.

[0035] It uses the working principle of an air source heat pump to generate heat, which is the opposite of the cooling principle of an air conditioner.

[0036] The working process of an air source heat pump includes the following four aspects.

[0037] (1) Evaporation process. Inside the evaporator, a low-boiling-point liquid working fluid (such as refrigerant) absorbs heat from the outdoor air and evaporates into vapor. The heat released in this process is the recovered heat.

[0038] (2) Compression process. The compressor compresses the low-temperature, low-pressure working fluid vapor into high-temperature, high-pressure vapor. This process further increases the temperature and pressure of the vapor, providing the necessary conditions for subsequent heat exchange.

[0039] (3) Condensation process. High-temperature and high-pressure steam enters the condenser, exchanges heat with water, releases heat, and heats the water. During this process, the steam gradually cools down and becomes a high-pressure liquid working fluid.

[0040] (4) Throttling process. The high-pressure liquid working fluid is throttled and depressurized through the expansion valve, and the temperature is reduced. It then becomes a low-temperature and low-pressure liquid working fluid again, and then enters the evaporator again to start the next cycle.

[0041] Simply put, an air source heat pump absorbs heat from the air to heat water.

[0042] In addition, air source heat pumps are equipped with a filtration system to remove impurities from the air, protect the equipment, and improve its efficiency.

[0043] At extremely low temperatures, the ultra-low temperature heat pump supplements the compressor with gas through the injection enthalpy-increasing branch, increasing the heat release of the condenser and ensuring normal heating even in low-temperature environments.

[0044] Working principle of water source heat pump The working principle of a water source heat pump is similar to that of an air source heat pump, except that a water source heat pump absorbs heat from the water source, while an air source heat pump absorbs heat from the air.

[0045] A water source heat pump also includes four components: evaporator, compressor, condenser, and throttling device.

[0046] The working process of a water source heat pump includes the following four aspects.

[0047] (1) Evaporation process. Inside the evaporator, a low-boiling-point liquid refrigerant (such as a refrigerant) absorbs heat from the water source and evaporates into steam. The heat released in this process is the recovered heat.

[0048] (2) Compression process. The compressor compresses low-temperature, low-pressure steam into high-temperature, high-pressure steam. This process further increases the temperature and pressure of the steam, providing the necessary conditions for subsequent heat exchange.

[0049] (3) Condensation process. High-temperature and high-pressure steam enters the condenser, exchanges heat with water, releases heat, and heats the water. During this process, the steam gradually cools down and becomes a high-pressure liquid working fluid.

[0050] (4) Throttling process. The high-pressure liquid working fluid is throttled and depressurized through the expansion valve, and the temperature is reduced. It then becomes a low-temperature and low-pressure liquid working fluid again, and then enters the evaporator again to start the next cycle.

[0051] In some embodiments of this application, a multi-heat source composite heating system is disclosed, wherein the multi-heat source includes an air source heat pump 110 and a water source heat pump 210.

[0052] In some embodiments of this application, when air source heat pump 110 and water source heat pump 210 are coupled for heating, how to balance user heating needs and high efficiency is a problem that this application needs to consider.

[0053] In some embodiments of this application, see Figure 1 The multi-heat source composite heating system includes a water source heat pump 210, a first control valve 220, an air source heat pump 110, a hot water storage tank 140, a second control valve 120, a water distributor 410, a third control valve 130, and a water collector 310.

[0054] The control unit 500 is connected to the air source heat pump 110 and the water source heat pump 210, and controls the opening and closing of the first control valve 220, the second control valve 120 and the third control valve 130.

[0055] Water collector 310 is used for external water collection.

[0056] The first control valve 220 is connected at one end to the water collector 310 and at the other end to the condenser-side inlet of the water source heat pump 210. The condenser-side outlet of the water source heat pump 210 is connected to the water distributor 410.

[0057] The second control valve 120 is connected at one end to the water collector 310 and the first control valve 220, and at the other end to the condenser side water inlet of the air source heat pump 110.

[0058] By controlling the opening of the second control valve 120, water is supplied to the condenser of the air source heat pump 110, forming the first circulating water path of the air source heat pump 110.

[0059] The third control valve 130 is connected at one end to the outlet of the condenser side of the hot water storage tank 140 and the air source heat pump 110, and at the other end to the water distributor 410.

[0060] By controlling the opening of the third control valve 130, the water in the first circulating water circuit exchanges heat with the condenser of the air source heat pump 110 and is then introduced into the water distributor 410.

[0061] The inlet of the hot water storage tank 140 is connected to the outlet of the air source heat pump 110 on the condenser side and the inlet of the hot water storage tank 140 at the connection point, and the outlet is connected to the inlet of the water source heat pump 210 on the evaporator side.

[0062] After the second control valve 120 is disconnected (i.e., the water path from the water collector 310 is cut off), the hot water storage tank 140 provides water to the condenser of the air source heat pump 110, forming the second circulating water path of the air source heat pump 110.

[0063] In some embodiments of this application, a hot water storage tank 140 is used, which also reduces the temperature fluctuation of the water after heat exchange in the condenser of the air source heat pump 110, so as to provide a stable low-temperature heat source for the water source heat pump 210.

[0064] In some embodiments of this application, in order to realize the drainage of the water collector 310, a system circulating water pump 320 is provided on the water supply pipeline of the water collector 310.

[0065] One end of the first control valve 220 is specifically connected to the system circulating water pump 320, and one end of the second control valve 120 is specifically connected at the connection point between the system circulating water pump 320 and the first control valve 220.

[0066] In order to provide circulation power to the water in the second circulation water line, an intermediate circulation water pump 150 is also provided in some embodiments of this application.

[0067] The intermediate circulating water pump 150 is installed in the second circulating water path where the air source heat pump 110 provides a low-temperature heat source for the water source heat pump 210.

[0068] See Figure 1 The intermediate circulating water pump 150 is located between the evaporator-side outlet of the water source heat pump 210 and the condenser-side inlet of the air source heat pump 110.

[0069] See Figure 1 In some embodiments of this application, a buffer tank 160 is provided between the water outlet end of the evaporator side of the water source heat pump 210 and the water inlet end of the condenser side of the air source heat pump 110, which is used to buffer the water temperature after heat exchange through the evaporator of the water source heat pump 210.

[0070] In some embodiments of this application, changes in ambient temperature or changes in user-demanded water temperature can affect the energy efficiency of air source heat pump 110, the energy efficiency of water source heat pump 210, and the overall system energy efficiency. Therefore, based on the ambient temperature or user-demanded water temperature, the system switches to the direct heating mode of air source heat pump 110 (hereinafter referred to as direct heating mode) or the coupled heating mode of air source heat pump 110 and water source heat pump 210 (hereinafter referred to as coupled supply mode).

[0071] See Figure 2The flowchart shows the process when the coupling heating mode is started.

[0072] In some embodiments of this application, when the ambient temperature is low or the user requires a high water temperature, the first control valve 220 is turned on and the second control valve 120 and the third control valve 130 are turned off.

[0073] When all control valves are switched on or off, the system circulating water pump 320, intermediate circulating water pump 150, water source heat pump 210 and air source heat pump 110 are all turned on, and the air source heat pump 110 and water source heat pump 210 are coupled to provide heat.

[0074] When air source heat pump 110 and water source heat pump 210 are coupled for heating, the water flow direction is as follows: Figure 3 As shown by the dashed line.

[0075] The heat released by the condenser of the air source heat pump 110 heats the water in the second circulating water circuit, and flows out through the hot water storage tank 140 to the evaporator side inlet of the water source heat pump 210.

[0076] The evaporator of the water source heat pump 210 absorbs the heat from the heated water and releases the heat at the condenser. The heat is exchanged with the water from the water collector 310. The water after heat exchange is discharged to the water distributor 410, thus realizing the user's need to prepare hot water.

[0077] In some embodiments of this application, the air source heat pump 110 serves as the primary heat pump of the entire system. It uses the heat energy in the air to produce hot water at a preset temperature, which then enters the water source heat pump 210. The water source heat pump 210 then raises the temperature to the user's desired temperature.

[0078] It should be noted that in the coupled heating mode involved in this application, the first control valve 220 is turned on, the second control valve 120 and the third control valve 130 are both turned off, and the system circulating water pump 320, the intermediate circulating water pump 150, the water source heat pump 210 and the air source heat pump 110 are all turned on.

[0079] In some embodiments of this application, when the air source heat pump 110 and the water source heat pump 210 are coupled for heating, the energy efficiency ratio of the air source heat pump 110, the energy efficiency ratio of the water source heat pump 210 and the total energy efficiency ratio of the system are considered, and the system is controlled to maintain the current coupled heating mode of the air source heat pump 110 and the water source heat pump 210 or switch to the direct heating mode of the air source heat pump 110. Details will be described below.

[0080] See Figure 4 It shows a flowchart of the process when starting the direct heating mode.

[0081] In some embodiments of this application, when the ambient temperature is high or the user requires a low water temperature, the second control valve 120 and the third control valve 130 are both turned on, and the first control valve 220 is turned off.

[0082] When all control valves are switched on or off, the system circulating water pump 320 and air source heat pump 110 are both turned on, while the intermediate circulating water pump 150 and water source heat pump 210 are both turned off, with only the air source heat pump 110 providing direct heat.

[0083] In the direct heating mode of the air source heat pump 110, see the water flow direction. Figure 5 As shown by the dashed line.

[0084] When the air source heat pump 110 is working, the heat released by the condenser heats the water in the first circulating water circuit and leads it to the water distributor 410 through the third control valve 130 to prepare hot water to meet the user's needs.

[0085] It should be noted that in the direct heating mode involved in this application, the first control valve 220 is disconnected, the second control valve 120 and the third control valve 130 are both connected, the system circulating water pump 320 and the air source heat pump 110 are both turned on, and the intermediate circulating water pump 150 and the water source heat pump 210 are both disconnected.

[0086] In direct heating mode, air source heat pumps are more efficient when the ambient temperature is high, or when the user's water temperature requirement is not high in a low-temperature environment.

[0087] As described above, the system can switch between coupled heating mode and direct heating mode by controlling the ambient temperature or the water temperature required by the user.

[0088] In some embodiments of this application, when the ambient temperature decreases or the user demands a higher water temperature, the control unit 500 controls the first control valve 220 to open, and the second control valve 120 and the third control valve 130 to disconnect. The system circulating water pump 320, intermediate circulating water pump 150, water source heat pump 210 and air source heat pump 110 are all turned on, and the system enters the coupled heating mode of air source heat pump 110 and water source heat pump 210.

[0089] Since ambient temperature affects users' demand for water temperature, ambient temperature should be considered first, followed by the user's desired water temperature.

[0090] Therefore, when the ambient temperature decreases, it enters the coupled heating mode.

[0091] When the ambient temperature does not decrease (e.g., increases) and the user's required water temperature increases, the system enters the coupled heating mode.

[0092] In some embodiments of this application, when the ambient temperature rises or the user's required water temperature decreases, the second control valve 120 and the third control valve 130 are both turned on, the first control valve 220 is turned off, the system circulating water pump 320 and the air source heat pump 110 are both turned on, and the intermediate circulating water pump 150 and the water source heat pump 210 are both turned off, entering the direct heating mode of the air source heat pump 110.

[0093] Since ambient temperature affects users' demand for water temperature, ambient temperature should be considered first, followed by the user's desired water temperature.

[0094] Therefore, when the ambient temperature rises, the air source water pump is highly efficient, thus entering the direct heating mode of the air source heat pump 110, thereby reducing energy consumption.

[0095] When the ambient temperature does not rise (e.g., it decreases) and the user's required water temperature decreases, the air source water pump is also highly efficient. Therefore, it enters the direct heating mode of the air source heat pump 110, thereby reducing energy consumption.

[0096] When entering the direct heating mode of the air source heat pump 110, the heating mode (including direct heating mode and coupled heating mode) can be switched according to the ambient temperature or user-required water temperature as described above.

[0097] It should be noted that the ambient temperature can be obtained by the ambient temperature sensor 600.

[0098] This application focuses on how, under coupled heating mode, the heating mode can be switched based on the energy efficiency ratio of the air source heat pump 110, the energy efficiency ratio of the water source heat pump 210, and the overall system energy efficiency ratio, so as to meet the user's heating needs while ensuring the system operates at its highest energy efficiency.

[0099] See Figure 6 It shows the control flow diagram in the coupled heating mode.

[0100] S1: The air source heat pump 110 starts at the target temperature, and the water source heat pump 210 starts at the user's target water temperature, and proceeds to S2.

[0101] In some embodiments of this application, both the air source heat pump 110 and the water source heat pump 210 are turned on, entering a coupled heating mode.

[0102] The target temperature of the air source heat pump 110 and the user's target water temperature of the water source heat pump 210 can both be preset.

[0103] In some embodiments of this application, in order to ensure that the heating capacity of the air source heat pump 110 can be largely met and used for the heat extraction of the water source heat pump 210, and to avoid energy waste, the target start-up temperature is obtained in advance before the system is started, and is used as the target temperature when the air source heat pump 110 is turned on.

[0104] The process of obtaining the target activation temperature is described below.

[0105] The hot water storage tank 140 not only provides a stable low-temperature heat source for the water source heat pump 210, but also provides a water source for the air source heat pump 110 when the second control valve 120 is disconnected.

[0106] Therefore, the temperature of the hot water storage tank 140 can represent the outlet water temperature discharged from the condenser side of the air source heat pump 110.

[0107] Under the current ambient temperature and the user's target water temperature Tw, as the water temperature in the hot water storage tank 140 rises, the heating capacity of the air source heat pump 110 gradually decreases; that is, the heating capacity of the air source heat pump 110 gradually decreases. (See [reference]). Figure 7 Line L1; while the heating capacity of the water source heat pump 210 increases with the increase of the water temperature in the hot water storage tank 140, see [reference]. Figure 7 L3 line.

[0108] Figure 7 The L2 line in the middle indicates the heat output of the water source heat pump 210.

[0109] When lines L1 and L2 intersect, the heating capacity of the air source heat pump 110 and the heat output of the water source heat pump 210 are the same, and a balance is reached. At this time, the temperature of the corresponding hot water storage tank 140 is t1.

[0110] The obtained t1 will be used as the target temperature for activation as described above.

[0111] The L1 and L2 lines can be found by querying the performance parameters of the heat pump product or by obtaining the actual performance curves through cloud data collection.

[0112] Thus, the air source heat pump 110 is turned on at the target temperature t1, and the water source heat pump 210 is turned on at the user's target water temperature Tw.

[0113] S2: Determine whether the user's requested water temperature meets the user's target water temperature. If yes, proceed to S3; otherwise, return to S2.

[0114] When entering the coupled heating mode, the goal is to meet the user's heating needs. Therefore, it is necessary to determine in real time whether the user's required water temperature has reached the user's target water temperature Tw.

[0115] In some embodiments of this application, under coupled heating mode, the outlet water temperature on the condenser side of the water source heat pump 210 is the actual required water temperature.

[0116] The required water temperature can be obtained through the temperature sensor on the water source heat pump 210.

[0117] S3: Increase the target water temperature of the air source heat pump 110 and proceed to S4.

[0118] If the user's required water temperature reaches the user's target water temperature Tw, it means that the user's heating needs have been met.

[0119] While meeting users' heating needs, ensuring the system operates at its highest energy efficiency is a crucial consideration.

[0120] In some embodiments of this application, the maximum value of the system's total energy efficiency ratio is sought by increasing the target temperature of the air source heat pump 110.

[0121] As described above, the air source heat pump 110 and the water source heat pump 210 are turned on. After the two heat pumps are working stably, the system calculates the energy efficiency ratio COP1 of the air source heat pump 110, the energy efficiency ratio COP2 of the water source heat pump 210 and the total energy efficiency ratio COP of the system, and records COP1, COP2 and COP for each period of time in real time.

[0122] Assuming that, under the current ambient temperature, the COP2 of the water source heat pump 210 is higher than the COP1 of the air source heat pump 110.

[0123] If the COP2 of a water source heat pump 210 is represented by curve L22, and the COP1 of an air source heat pump 110 is represented by curve L11, their curve changes are as follows: Figure 8 .

[0124] The curve of the system's total energy efficiency ratio (COP) is located between the COP1 curve and the COP2 curve, and the shape of the curve is close to that of the COP2 curve.

[0125] Increasing the target temperature of the air source heat pump 110 (i.e., increasing the temperature of the hot water storage tank 140) will decrease the COP1 of the air source heat pump 110, while the COP2 of the water source heat pump 210 will decrease after rising to a certain value. That is, at this time, COP1, COP2 and COP are all changing.

[0126] The system records the overall energy efficiency ratio (COP). After increasing the target temperature of the air source heat pump 110, the COP may increase or decrease.

[0127] If the system's overall energy efficiency ratio (COP) rises to a certain value and then decreases, and then returns to the previous value, this value is the energy efficiency peak, and the system records it.

[0128] S4: Determine if COP1 is greater than COP. If yes, proceed to S5; otherwise, proceed to S8.

[0129] In some embodiments of this application, the COP1 of the air source heat pump 110 is lower than the COP2 of the water source heat pump 210 under different ambient temperatures. See [link to relevant documentation]. Figure 8 Alternatively, the COP1 of an air source heat pump 110 will be higher than the COP2 of a water source heat pump 210.

[0130] However, regardless of the circumstances, the total system power ratio (COP) curve lies between the COP1 and COP2 curves, and its trend is similar to that of COP2.

[0131] Therefore, when adjusting the target temperature of the air source heat pump 110 to increase, as mentioned above, the COP may increase or decrease. First, it is necessary to determine whether COP1 is greater than COP.

[0132] As mentioned above, COP1, COP2, and COP are all acquired in real time during system operation.

[0133] S5: Switch to direct heating mode and proceed to S6.

[0134] When COP1 is greater than COP, the control unit 500 controls the first control valve 220, which is currently open, to be disconnected, and the second control valve 120 and the third control valve 130, which are currently disconnected, to be connected. The circulating water pump 320 and the air source heat pump 110 are kept on, and the intermediate circulation pump and the water source heat pump 210, which are currently open, are disconnected. The system switches from coupled heating mode to direct heating mode.

[0135] S6: Determine if the ambient temperature has decreased. If yes, proceed to S7; otherwise, determine if the user's target water temperature has increased. If yes, proceed to S7; otherwise, return to S6.

[0136] Since ambient temperature affects users' heating needs, in some embodiments of this application, the influence of ambient temperature is given priority, followed by the influence of the user's target water temperature requirement.

[0137] Therefore, first determine whether the ambient temperature has decreased, and then determine whether the user's target water temperature has increased.

[0138] S7: If COP1 reaches the energy efficiency ratio of the water source heat pump 210 when switching to direct heating mode, start the water source heat pump 210 at the current user target water temperature and return to S2.

[0139] When switching to direct heating mode in S5, it is necessary to record the energy consumption ratio of water source heat pump 210 at the time of switching. This value is recorded as COP2'.

[0140] In direct heating mode, the energy efficiency ratio (COP1) of the air source heat pump 110 is calculated in real time.

[0141] When COP1 reaches COP2', it means that COP1 is greater than or equal to COP2', that is, the current energy efficiency ratio of the air source heat pump 110 is still relatively high, so the current direct heating mode is maintained.

[0142] When COP1 does not reach COP2', it means that COP1 is less than COP2', that is, the current energy efficiency ratio of the air source heat pump 110 is relatively low. Therefore, the direct heating mode is not used alone, and the coupled heating mode is switched at this time.

[0143] That is, the control unit 500 turns on the disconnected first control valve 220, turns off the connected second control valve 120 and third control valve 130, keeps the system circulation pump and air source heat pump 110 on, and turns on the disconnected intermediate circulation water pump 150 and water source heat pump 210, thereby switching from direct heating mode to coupled heating mode.

[0144] Among them, the water source heat pump 210 is started based on the current updated user target water temperature requirement.

[0145] S8: Determine if the system's overall energy efficiency ratio (COP) has increased. If yes, proceed to S9; otherwise, proceed to S93.

[0146] At the current ambient temperature, raising the target temperature of the air source heat pump 110 will cause a change in the system's overall energy efficiency ratio (COP), which may increase or decrease.

[0147] As mentioned above, the system needs to record the maximum energy efficiency (i.e., the energy efficiency peak). That is, when the energy efficiency ratio rises to a certain value, then decreases, and then rises back to the previous value, this value is the energy efficiency peak.

[0148] Therefore, it is necessary to determine whether the system has reached its energy efficiency peak based on the trend of the overall energy efficiency ratio (COP), where the energy efficiency peak is denoted as COP'.

[0149] The first step should be to determine whether the overall energy efficiency ratio has increased.

[0150] S9: Determine whether the system's total energy efficiency ratio (COP) has reached its energy efficiency peak. If yes, proceed to S91; otherwise, return to S3.

[0151] When the overall system efficiency ratio (COP) increases, determine whether the high efficiency point (COP') has been reached.

[0152] If the high energy efficiency point COP' is reached, then the ambient temperature or the target temperature of the air source heat pump 110 will be judged, and the specific judgment is described below.

[0153] If the high energy efficiency ratio COP' is not reached, return to S3 and raise the target temperature of the air source heat pump 110. The energy efficiency ratio COP1 of the air source heat pump 110, the energy efficiency ratio COP2 of the water source heat pump 210, and the total energy efficiency ratio COP of the system will all change.

[0154] S91: Determine if the ambient temperature has increased. If yes, return to S3. Otherwise, determine if the ambient temperature has decreased. If yes, proceed to S93. If no, proceed to S92.

[0155] Since ambient temperature affects users' demand for water temperature, we should take the change in ambient temperature first, and then consider the user's target water temperature.

[0156] Therefore, when the ambient temperature rises, return to S3 to raise the target temperature of the air source heat pump 110.

[0157] If the ambient temperature does not rise, then determine whether the ambient temperature has decreased.

[0158] If the ambient temperature does not decrease, it means that the ambient temperature will neither increase nor decrease, that is, maintain the current ambient temperature, and then determine the user's target temperature requirement.

[0159] When the ambient temperature decreases, proceed to S93 to lower the target temperature of the air source heat pump 110.

[0160] S92: Determine whether the user's target water temperature has decreased. If yes, return to S3. Otherwise, determine whether the user's target water temperature has increased. If yes, proceed to S93. If no, return to S91.

[0161] If the ambient temperature neither rises nor falls, then determine the user's target temperature requirement.

[0162] When the ambient temperature neither rises nor falls, and when the user's target water temperature decreases, return to S3 and raise the target temperature of the air source heat pump 110.

[0163] When the ambient temperature neither rises nor falls, and when the user's target water temperature rises, proceed to S93 to lower the target temperature of the air source heat pump 110.

[0164] If the ambient temperature does not rise or fall, and the user's target water temperature does not rise or fall, return to S91 to re-evaluate the ambient temperature and the user's target water temperature.

[0165] S93: Reduce the target water temperature of the air source heat pump 110 and proceed to S94.

[0166] As mentioned above, since the total energy consumption ratio of the system may increase or decrease, if the total energy efficiency ratio (COP) does not increase, then in order to find the high point of the total energy efficiency ratio, it is necessary to lower the target water temperature of the air source heat pump 110.

[0167] S94: Determine whether the system's overall energy efficiency ratio (COP) has increased. If yes, proceed to S95; otherwise, proceed to S91.

[0168] After lowering the target water temperature of the air source heat pump 110, if the system's overall energy efficiency ratio (COP) increases, it will then be determined whether the energy efficiency peak has been reached.

[0169] If the overall system efficiency ratio (COP) decreases, it means that no matter whether the target water temperature of the air source heat pump 110 is lowered or raised, the COP cannot be increased. Therefore, at this point, the COP has reached the energy efficiency peak, and so proceed to S91.

[0170] S95: Determine whether the system's overall energy efficiency ratio (COP) has reached its energy efficiency peak. If yes, proceed to S91; otherwise, return to S93.

[0171] When the overall system efficiency ratio (COP) increases, determine whether the high efficiency point (COP'') has been reached.

[0172] If the high energy efficiency point COP is reached, proceed to S91, and then determine the ambient temperature or the target temperature of the air source heat pump 110.

[0173] If the high energy efficiency COP'' is not reached, return to S93 and continue to lower the target temperature of the air source heat pump 110. The energy efficiency ratio COP1 of the air source heat pump 110, the energy efficiency ratio COP2 of the water source heat pump 210, and the total energy efficiency ratio COP of the system will all change.

[0174] Thus, after entering the coupled heating mode, while meeting the user's heating needs, the target temperature of the air source heat pump 110 is increased to change the energy efficiency ratio, thereby switching to the direct heating mode when the air source heat pump 110 is in high energy efficiency, so as to meet the system's efficient direct heating needs.

[0175] Furthermore, when the air source heat pump 110 is not very efficient, the system can obtain a high point of energy efficiency by changing the target temperature of the air source heat pump 110, thus meeting the system's efficient coupled heating needs, while still meeting the user's heating requirements.

[0176] Furthermore, in the high-efficiency heating mode, the impact of ambient temperature and user target temperature on the heating mode is further assessed.

[0177] In some embodiments of this application, in S3 as described above, a delay is required when raising the target temperature of the air source heat pump 110 (see...). Figure 6Then, the energy efficiency ratio is judged (i.e., S4) to provide time for the heating system to operate stably after the target temperature of the air source heat pump 110 is raised.

[0178] In some embodiments of this application, in S93 as described above, a delay is required for a certain period of time when lowering the target temperature of the air source heat pump 110 (see...). Figure 6 Then, the energy efficiency ratio is judged again (i.e., S94) to provide time for the heating system to operate stably after the target temperature of the air source heat pump 110 is reduced.

[0179] In some embodiments of this application, the heat source involved in the heating system also includes a boiler 710.

[0180] See Figure 10 The boiler 710 and the water source heat pump 210 are arranged side by side.

[0181] The fourth control valve 720 is used to control the flow of water from the collector 310 into the boiler 710, which is connected to the distributor 410.

[0182] In some embodiments of this application, the boiler 710 is communicatively connected to the control unit 500 and is started by the control unit 500.

[0183] Boiler 710 is independent of air source heat pump 110 and water source heat pump 210, and directly produces hot water for users.

[0184] In coupled heating mode, if both air source heat pump 110 and water source heat pump 210 are operating at full load, the user's heating demand still cannot be met. (See [reference needed]) Figure 9 The control unit 500 then controls the fourth control valve 720 to open.

[0185] When all control valves are switched on or off, the system circulating water pump 320, intermediate circulating water pump 150, water source heat pump 210, air source heat pump 110 and boiler 710 are all turned on, and the boiler 710, air source heat pump 110 and water source heat pump 210 work together to provide heating.

[0186] When boiler 710, air source heat pump 110, and water source heat pump 210 are used for combined heating, the water flow direction is as follows: Figure 10 As shown by the dashed line.

[0187] The heat released by the condenser of the air source heat pump 110 heats the water in the second circulating water circuit, and flows out through the hot water storage tank 140 to the evaporator side inlet of the water source heat pump 210.

[0188] The evaporator of the water source heat pump 210 absorbs the heat from the heated water and releases the heat at the condenser. The heat is exchanged with the water from the water collector 310. The water after heat exchange is discharged to the water distributor 410, thus realizing the user's need to prepare hot water.

[0189] Boiler 710 discharges water to distributor 410 through fourth control valve 720 to prepare hot water to meet user needs.

[0190] In order to reduce energy consumption in the combined heating process, the control unit 500 monitors the user's heating demand. If the user's heating demand decreases, the control unit 500 gradually controls the reduction of the power of the boiler 710 or turns the boiler 710 on intermittently to save energy.

[0191] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0192] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A multi-heat source composite heating system, characterized in that, include: Water source heat pump; The first control valve is used to control whether water from the water collector is supplied to the condenser side of the water source heat pump; An air source heat pump that provides a low-temperature heat source to the water source heat pump; The second control valve is used to control whether water from the water collector is supplied to the condenser side of the air source heat pump; The water distributor is connected to the condenser-side outlet of the water source heat pump. The third control valve is used to control the supply of water after heat exchange on the condenser side of the air source heat pump to the water distributor or the evaporator side of the water source heat pump. The hot water storage tank has its inlet end connected between the third control valve and the outlet end of the air source heat pump on the condenser side, and its outlet end connected to the inlet end of the water source heat pump on the evaporator side. An ambient temperature sensor is used to detect the ambient temperature of the multi-heat source composite heating system. A control unit is used to control whether water is supplied to the multi-heat source composite heating system through the water collector, and the control unit is communicatively connected to both the air source heat pump and the water source heat pump. The control unit controls the first control valve, the second control valve, the third control valve, the air source heat pump, and the water source heat pump based on the ambient temperature or the user's required water temperature, so as to enter the direct heating mode of the air source heat pump or the coupled heating mode of the air source heat pump and the water source heat pump. In the coupled heating mode, based on the energy efficiency ratio of the air source heat pump, the energy efficiency ratio of the water source heat pump, the total energy efficiency ratio of the system, the ambient temperature, and the user's target water temperature requirement, the system controls and maintains the coupled heating mode or switches to the direct heating mode.

2. The multi-heat source composite heating system according to claim 1, characterized in that, The multi-heat source composite heating system also includes: An intermediate circulating water pump is installed in the circulation loop where the air source heat pump provides a low-temperature heat source to the water source heat pump; A buffer tank, the water inlet of which is connected to the water outlet on the evaporator side of the water source heat pump, and the water outlet of which is connected to the water inlet on the condenser side of the air source heat pump; The control unit controls the opening and closing of the intermediate circulating water pump based on the opening and closing of the air source heat pump.

3. The multi-heat source composite heating system according to claim 1, characterized in that, The control unit controls the first control valve, the second control valve, the third control valve, the air source heat pump, and the water source heat pump based on the ambient temperature or the user's required water temperature, specifically: When the ambient temperature decreases or the user requests a higher water temperature, the control unit controls the first control valve to open, the second control valve and the third control valve to close, and the air source heat pump and the water source heat pump to start. When the ambient temperature rises or the user requests a lower water temperature, the control unit controls the first control valve to disconnect, the second control valve and the third control valve to open, the air source heat pump to start, and the water source heat pump to disconnect.

4. The multi-heat source composite heating system according to claim 1, characterized in that, In the case of coupled heating, based on the COP1 of the air source heat pump, the COP2 of the water source heat pump, the overall system COP, the ambient temperature, and the user's target water temperature requirement, the system is controlled to maintain the coupled heating mode or switch to direct heating mode, specifically as follows: S1: The air source heat pump is turned on with the target temperature as the target temperature, and the water source heat pump is turned on with the user's target water temperature as the user's target water temperature, and then proceeds to S2. S2: Determine whether the user's requested water temperature meets the user's target water temperature. If yes, proceed to S3; otherwise, return to S2. S3: Increase the target water temperature of the air source heat pump and proceed to S4; S4: Determine if COP1 is greater than COP. If yes, proceed to S5; otherwise, proceed to S8. S5: Switch to direct heating mode and proceed to S6; S6: Determine if the ambient temperature has decreased. If yes, proceed to S7; otherwise, determine if the user's target water temperature has increased. If yes, proceed to S7; otherwise, return to S6. S7: If COP1 reaches the energy efficiency ratio of the water source heat pump when switching to direct heating mode, start the water source heat pump with the current user target water temperature and return to S2. S8: Determine whether the system's overall energy efficiency ratio (COP) has increased. If yes, proceed to S9; otherwise, proceed to S93. S9: Determine whether the system's overall energy efficiency ratio (COP) has reached its energy efficiency peak. If yes, proceed to S91; otherwise, return to S3. S91: Determine if the ambient temperature has increased. If yes, return to S3. Otherwise, determine if the ambient temperature has decreased. If yes, proceed to S93. If no, proceed to S92. S92: Determine whether the user's target water temperature has decreased. If yes, return to S3. Otherwise, determine whether the user's target water temperature has increased. If yes, proceed to S93. If no, return to S91. S93: Reduce the target water temperature of the air source heat pump and proceed to S94; S94: Determine whether the system's overall energy efficiency ratio (COP) has increased. If yes, proceed to S95; otherwise, proceed to S91. S95: Determine whether the system's overall energy efficiency ratio (COP) has reached its energy efficiency peak. If yes, proceed to S91; otherwise, return to S93.

5. The multi-heat source composite heating system according to claim 4, characterized in that, After raising the target water temperature of the air source heat pump for a period of time in S3, it is then determined whether COP1 is greater than COP in S4. After lowering the target water temperature of the air source heat pump for a period of time in S93, it is then determined in S94 whether the system's total energy efficiency ratio (COP) has increased.

6. The multi-heat source composite heating system according to claim 4, characterized in that, The method for obtaining the target temperature is as follows: Under the current ambient temperature and the user's target water temperature, when the heating capacity of the air source heat pump and the heat output of the water source heat pump are balanced, the outlet water temperature of the hot water storage tank is determined. Set the determined outlet water temperature of the hot water storage tank as the target opening temperature.

7. The multi-heat source composite heating system according to claim 1, characterized in that, The multi-heat source composite heating system also includes: A system circulating water pump is installed on the water supply pipeline of the water collector, and the system circulating water pump is connected to the control unit.

8. A multi-heat source composite heating system, characterized in that, include: Water source heat pump; The first control valve is used to control whether water from the water collector is supplied to the condenser side of the water source heat pump; An air source heat pump that provides a low-temperature heat source to the water source heat pump; The second control valve is used to control whether water from the water collector is supplied to the condenser side of the air source heat pump; The water distributor is connected to the condenser-side outlet of the water source heat pump. The third control valve is used to control the supply of water after heat exchange on the condenser side of the air source heat pump to the water distributor or the evaporator side of the water source heat pump. The hot water storage tank has its inlet end connected between the third control valve and the outlet end of the air source heat pump on the condenser side, and its outlet end connected to the inlet end of the water source heat pump on the evaporator side. An ambient temperature sensor is used to detect the ambient temperature of the multi-heat source composite heating system. A boiler, which is arranged in parallel with the water source heat pump; The fourth control valve is used to control whether water from the water collector is supplied to the boiler; The control unit is used to control whether water is supplied to the multi-heat source composite heating system through the water collector, and the control unit is communicatively connected to the air source heat pump, the water source heat pump and the boiler. The control unit controls the first control valve, the second control valve, the third control valve, the air source heat pump, and the water source heat pump based on the ambient temperature or the user's required water temperature, so as to enter the direct heating mode of the air source heat pump or the coupled heating mode of the air source heat pump and the water source heat pump. In the coupled heating mode, based on the energy efficiency ratio of the air source heat pump, the energy efficiency ratio of the water source heat pump, the total energy efficiency ratio of the system, the ambient temperature, and the user's target water temperature, the system controls and maintains the coupled heating mode or switches to the direct heating mode. When both the air source heat pump and the water source heat pump are operating at full load and still cannot meet the user's heating needs, the control unit then controls the fourth control valve to open and controls the boiler to start.

9. The multi-heat source composite heating system according to claim 8, characterized in that, The control unit monitors the user's heating demand. If the user's heating demand decreases, the control unit gradually controls the reduction of the boiler's power or turns the boiler on intermittently.

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