High-temperature heat pump system with multiple operating modes

Abstract

The present application relates to a high-temperature heat pump system with multiple operating modes, which includes a high-pressure compressor, a low-pressure compressor, a condenser, a first solenoid valve, a second solenoid valve, a flash tank, an economizer, a first throttle valve, a second throttle valve, and an evaporator. When the entire system is in operation, by controlling the opening and closing of the first solenoid valve and the second solenoid valve, the high-temperature and high-pressure refrigerant output by the condenser can be reduced in pressure through the first throttle valve or the second throttle valve, and then enter the flash tank or undergo heat exchange with the refrigerant in the economizer respectively; at the same time, the high-pressure gaseous refrigerant in the flash tank replenishes the high-pressure compressor; or the low-pressure gaseous refrigerant after the second throttle valve replenishes the low-pressure compressor. The entire system adopts two-stage pressurization, and adopts gas replenishment technology at the high-pressure compressor and the low-pressure compressor respectively, which reduces the compressor exhaust temperature and increases the refrigerant mass flow rate, which can significantly improve the energy efficiency of the heat pump system.

Description

Technical Field

[0001] The present application relates to the field of heat pump technology, and in particular to a high-temperature heat pump system with multiple operating modes. Background Art

[0002] Steam heating is a common practice in industrial production processes, such as textiles, cigarettes, and papermaking. Currently, coal-fired or gas-fired boilers are the primary heat source. These boilers suffer from low heating efficiency, require high operator skills, and pose potential safety risks.

[0003] Compared with electric heating, heat pump heating technology has higher heating efficiency, and the high-temperature heat pump system greatly improves the heating temperature of the heat pump and expands the scope of use of the heat pump.

[0004] However, as the heating temperature of the heat pump increases, the energy efficiency of the heat pump system decreases seriously. Therefore, how to provide a high-energy-efficiency heat pump system has become a technical problem that needs to be solved. Summary of the Invention

[0005] Based on this, it is necessary to provide a high-energy-efficiency, multi-operation-mode high-temperature heat pump system.

[0006] The present application provides a high-temperature heat pump system with multiple operating modes, the system comprising a high-pressure compressor, a low-pressure compressor, a condenser, a first solenoid valve, a second solenoid valve, a flash tank, an economizer, a first throttle valve, a second throttle valve, and an evaporator;

[0007] The output end of the low-pressure compressor is connected to the input end of the high-pressure compressor, the output end of the high-pressure compressor is connected to the input end of the condenser, the output end of the condenser is respectively connected to one end of the first solenoid valve and one end of the second solenoid valve, the other end of the first solenoid valve is connected to the input end of the flash tank through the first throttle valve, the exhaust port of the flash tank is connected to the air supply port of the high-pressure compressor, the output end of the flash tank is connected to the input end of the evaporator, the other end of the second solenoid valve is respectively connected to the input end of the second throttle valve and the input end of the economizer, the output end of the second throttle valve is connected to the air supply port of the low-pressure compressor, the output end of the economizer is connected to the input end of the evaporator, and the output end of the evaporator is connected to the input end of the low-pressure compressor;

[0008] The refrigerant after the pressure drop through the second throttle valve exchanges heat with the refrigerant in the economizer and then flows into the air supply port of the low-pressure compressor.

[0009] In one embodiment, the multi-operation mode high-temperature heat pump system further includes a third throttle valve; the flash tank and the economizer are connected to the evaporator via the third throttle valve.

[0010] In one embodiment, the multi-operation-mode high-temperature heat pump system further includes a heat load module, which performs heat exchange with the condenser and is used to provide heat energy to external user equipment.

[0011] In one embodiment, the heat load module includes a heat exchange component, a third solenoid valve, a fourth solenoid valve, and a heat storage component;

[0012] The heat exchange component exchanges heat with the condenser, the input end of the heat exchange component is connected to an external water source, the output end of the heat exchange component is respectively connected to one end of the third solenoid valve and one end of the fourth solenoid valve, the other end of the third solenoid valve is connected to the heat storage component, and the other end of the fourth solenoid valve is connected to the external user equipment.

[0013] In one embodiment, the heat storage component includes a heat storage component using an inorganic hydrated salt, or a heat storage component using mineral oil.

[0014] In one embodiment, the multi-operation mode high-temperature heat pump system further includes a controller connected to the control ends of the first solenoid valve and the second solenoid valve;

[0015] In the energy efficiency ratio priority operation mode, the controller controls the first solenoid valve to open and controls the second solenoid valve to close;

[0016] In the heating amount priority operation mode, the controller controls the first solenoid valve to be closed and controls the second solenoid valve to be open.

[0017] In one embodiment, the controller is further connected to the first throttle valve;

[0018] The controller adjusts the opening of the first throttle valve to adjust the internal pressure of the flash tank to maintain a preset flash tank target pressure, where the preset flash tank target pressure is determined based on a condenser pressure and an evaporator pressure.

[0019] In one embodiment, the controller is further configured to adjust the opening of the first throttle valve so as to adjust the internal pressure of the flash tank to maintain a preset flash tank target pressure using a PID (Proportional-Integral-Derivative) pressure control algorithm.

[0020] In one embodiment, the controller is further configured to adopt an energy efficiency priority operation mode when the compressor driving power is gray electricity; and adopt a heating amount priority operation mode when the compressor driving power is green electricity.

[0021] In one embodiment, the multi-operation mode high-temperature heat pump system further includes a controller connected to the control ends of the first solenoid valve, the second solenoid valve, the third solenoid valve, and the fourth solenoid valve;

[0022] In the energy efficiency ratio priority operation mode, the controller controls the first solenoid valve to open and controls the second solenoid valve to close;

[0023] In the heating priority operation mode, the controller controls the first solenoid valve to close and controls the second solenoid valve to open;

[0024] In the pure heat storage mode, the controller controls the third solenoid valve to open and controls the fourth solenoid valve to close;

[0025] In the heat extraction mode, the controller controls the third solenoid valve to close and controls the fourth solenoid valve to open.

[0026] The multi-mode high-temperature heat pump system includes a high-pressure compressor, a low-pressure compressor, a condenser, a first solenoid valve, a second solenoid valve, a flash tank, an economizer, a first throttle valve, a second throttle valve, and an evaporator. During operation, the refrigerant is compressed by the low-pressure compressor and then the high-pressure compressor before entering the condenser, releasing heat to the external load (providing heat to the user). By controlling the opening and closing of the first and second solenoid valves, the high-temperature, high-pressure refrigerant output from the condenser can be reduced in pressure by the first or second throttle valve before entering the flash tank or undergoing heat exchange with the refrigerant in the economizer. Simultaneously, the high-pressure gaseous refrigerant in the flash tank replenishes the high-pressure compressor, or the low-pressure gaseous refrigerant after passing through the second throttle valve replenishes the low-pressure compressor. The remaining cooled and reduced-pressure refrigerant flows back to the evaporator. Because the entire system utilizes two-stage pressurization and employs gas replenishment technology at both the high-pressure and low-pressure compressors, the exhaust temperature of the compressors (both high-pressure and low-pressure compressors) is reduced while increasing the refrigerant mass flow rate, significantly improving the energy efficiency of the heat pump system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A schematic structural diagram of a high-temperature heat pump system with multiple operating modes according to an embodiment of the present invention;

[0028] Figure 2 This is a structural diagram of a high-temperature heat pump system with multiple operating modes according to another embodiment of the present invention;

[0029] Figure 3 This is a structural diagram of a high-temperature heat pump system with multiple operating modes in another embodiment of the present application;

[0030] Figure 4A schematic diagram of an operating state corresponding to an energy efficiency ratio priority operating mode in one embodiment;

[0031] Figure 5 Schematic diagram of the operating status corresponding to the heating amount priority operating mode in one embodiment. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0033] like Figure 1 As shown, a high-temperature heat pump system with multiple operating modes includes a high-pressure compressor 110, a low-pressure compressor 120, a condenser 130, a first solenoid valve 140, a second solenoid valve 150, a flash tank 160, an economizer 170, a first throttle valve 180, a second throttle valve 190 and an evaporator 210;

[0034] The output end of the low-pressure compressor 120 is connected to the input end of the high-pressure compressor 110, the output end of the high-pressure compressor 110 is connected to the input end of the condenser 130, the output end of the condenser 130 is respectively connected to one end of the first solenoid valve 140 and one end of the second solenoid valve 150, the other end of the first solenoid valve 140 is connected to the input end of the flash tank 160 through the first throttle valve 180, the exhaust port of the flash tank 160 is connected to the air supply port of the high-pressure compressor 110, the output end of the flash tank 160 is connected to the input end of the evaporator 210, the other end of the second solenoid valve 150 is respectively connected to the input end of the second throttle valve 190 and the input end of the economizer 170, the output end of the second throttle valve 190 is connected to the air supply port of the low-pressure compressor 120, the output end of the economizer 170 is connected to the input end of the evaporator 210, and the output end of the evaporator 210 is connected to the input end of the low-pressure compressor 120;

[0035] The refrigerant whose pressure has been reduced by the second throttle valve 190 exchanges heat with the refrigerant in the economizer 170 and then flows into the air supply port of the low-pressure compressor 120 .

[0036] High-pressure compressor 110, as the final stage of the system's compression process, has its input connected to the output of low-pressure compressor 120, receiving the refrigerant gas initially compressed by low-pressure compressor 120. High-pressure compressor 110 is equipped with a gas injection port, which is connected to the exhaust port of flash tank 160 and is used to receive gaseous refrigerant discharged from flash tank 160. This port injects gas and increases enthalpy, thereby improving compressor efficiency and refrigerant temperature and pressure.

[0037] The low-pressure compressor 120 is responsible for the front-end of the system's compression process. Its input is connected to the output of the evaporator 210, drawing in low-temperature, low-pressure gaseous refrigerant from the evaporator 210. The low-pressure compressor 120 is also equipped with a gas injection port, which is connected to the economizer 170 via a second throttle valve 190. This port is used to receive refrigerant gas after heat exchange with the economizer 170, thereby enhancing the compressor's compression capacity. It should be noted that the "high pressure" and "low pressure" described above with respect to the high-pressure compressor 110 and the low-pressure compressor 120 are relative terms, and this application does not limit the specific operating pressure values ​​of the two compressors.

[0038] The input of condenser 130 is connected to the output of high-pressure compressor 110, receiving high-pressure, high-temperature gaseous refrigerant. Within condenser 130, the refrigerant exchanges heat with the surrounding environment, releasing heat. Some of the refrigerant transforms from gas to liquid, while some remains in a gaseous state. The output of condenser 130 is connected to one end of a first solenoid valve 140 and a second solenoid valve 150, respectively. The refrigerant flows along different paths depending on the switch status of these solenoid valves.

[0039] Evaporator 210 is the heat-absorbing component of the system. Its input is connected to the output of flash tank 160 and the output of economizer 170, respectively, receiving refrigerant from these two components. In evaporator 210, the refrigerant absorbs heat from the air or other waste heat source, transforming from liquid to gas. The refrigerant is then output to the input of low-pressure compressor 120, completing a cycle.

[0040] The input of economizer 170 is connected to the other end of second solenoid valve 150, and its output is connected to the input of evaporator 210. Economizer 170's function is to subcool some of the refrigerant as it flows through the refrigerant by exchanging heat with another refrigerant, while also generating gaseous refrigerant to provide replenishment for low-pressure compressor 120.

[0041] The input end of flash tank 160 is connected to the other end of first solenoid valve 140, the exhaust port is connected to the gas supply port of high-pressure compressor 110, and the output end is connected to the input end of evaporator 210. Flash tank 160 receives refrigerant from condenser 130 through first solenoid valve 140, performs gas-liquid separation within the tank, and the gaseous refrigerant enters the high-pressure compressor 110 through the exhaust port for gas supply, while the liquid refrigerant is output to evaporator 210.

[0042] The input end of second throttle valve 190 is connected to the other end of second solenoid valve 150, and the output end is connected to the air supply port of low-pressure compressor 120. A portion of the refrigerant passing through second solenoid valve 150 undergoes pressure reduction through second throttle valve 190, undergoes heat exchange with the refrigerant in economizer 170, and then flows into the air supply port of low-pressure compressor 120, providing air supply to low-pressure compressor 120 and improving system performance.

[0043] In practical applications, the entire system can adopt the flash tank air supply mode and the economizer air supply mode. The details are as follows:

[0044] Flash tank air supply mode. When the first solenoid valve 140 is opened and the second solenoid valve 150 is closed, the system enters the flash tank 160 air supply mode. At this time, the liquid refrigerant output by the condenser 130 enters the flash tank 160 through the first solenoid valve 140. In the flash tank 160, the refrigerant is separated into gas and liquid, and the gaseous refrigerant enters the air supply port of the high-pressure compressor 110 through the exhaust port, replenishing the high-pressure compressor 110 with air and increasing the enthalpy, thereby improving the efficiency of the high-pressure compressor 110 and the condensation temperature and pressure of the refrigerant. The liquid refrigerant flows out from the output end of the flash tank 160, enters the evaporator 210, absorbs heat and becomes gaseous, then enters the low-pressure compressor 120 for preliminary compression, and finally enters the high-pressure compressor 110 to complete the entire compression cycle. In this mode, the system mainly uses the flash tank 160 to realize the air supply function, which is suitable for specific working conditions.

[0045] Economizer air supply mode. When the second solenoid valve 150 is open and the first solenoid valve 140 is closed, the system switches to economizer 170 air supply mode. The liquid refrigerant output from the condenser 130 passes through the second solenoid valve 150 and is divided into two paths: one path enters the economizer 170, and the other path passes through the second throttle valve 190 for pressure reduction. The refrigerant entering the economizer 170 and the refrigerant after the pressure reduction by the second throttle valve 190 undergo heat exchange within the economizer 170, causing the refrigerant entering the economizer 170 to be supercooled and generating gaseous refrigerant. After passing through the second throttle valve 190 and exchanging heat with the refrigerant in the economizer 170, the gaseous refrigerant flows into the air supply port of the low-pressure compressor 120, replenishing the low-pressure compressor 120. The supercooled liquid refrigerant enters the evaporator 210 from the output of the economizer 170, absorbs heat, and becomes gaseous, entering the low-pressure compressor 120, completing the cycle. This mode achieves supplementary air and refrigerant subcooling through the economizer 170, thereby improving the energy efficiency of the system under different operating conditions.

[0046] In actual applications, the evaporation temperature of the refrigerant is higher than 50°C, and the condensation temperature is higher than 120°C. Under such high-temperature conditions, traditional heat pump systems often face the problem of low energy efficiency. The high-temperature heat pump system with multiple operating modes in this application adopts compressor air supply technology, which can effectively improve the energy efficiency of the system whether it is the flash tank 160 air supply mode or the economizer 170 air supply mode. During the air supply process, the enthalpy value of the refrigerant is increased, and the compression efficiency of the compressor is improved, so that the system can still maintain high performance under high-temperature conditions, thereby expanding the application range of the heat pump system and meeting the user's needs for high-temperature heat sources in different scenarios.

[0047] The multi-operation mode high-temperature heat pump system includes a high-pressure compressor 110, a low-pressure compressor 120, a condenser 130, a first solenoid valve 140, a second solenoid valve 150, a flash tank 160, an economizer 170, a first throttle valve 180, a second throttle valve 190 and an evaporator 210. When the entire system is in operation, the refrigerant is compressed in turn by the low-pressure compressor 120 and the high-pressure compressor 110 before entering the condenser 130 to release heat to the external load (provide heat to the user). By controlling the opening and closing of the first solenoid valve 140 and the second solenoid valve 150, the high-temperature and high-pressure refrigerant output by the condenser 130 can be reduced in pressure through the first throttle valve 180 or the second throttle valve 190, and then enter the flash tank 160 respectively, or exchange heat with the refrigerant in the economizer 170; at the same time, the high-pressure gaseous refrigerant in the flash tank 160 replenishes the high-pressure compressor 110; or the low-pressure gaseous refrigerant after passing through the second throttle valve 190 replenishes the low-pressure compressor 120, and the remaining refrigerant after cooling and reducing pressure flows back to the evaporator 210. Since the entire system adopts two-stage boosting and air replenishment technology is used at the high-pressure compressor 110 and the low-pressure compressor 120 respectively, the exhaust temperature of the compressors (including the high-pressure compressor 110 and the low-pressure compressor 120) is reduced, and the refrigerant mass flow rate is increased at the same time, which can significantly improve the energy efficiency of the heat pump system.

[0048] In one embodiment, Figure 2 As shown, the multi-operation mode high-temperature heat pump system further includes a third throttle valve 220 ; the flash tank 160 and the economizer 170 are connected to the evaporator 210 via the third throttle valve 220 .

[0049] In this embodiment, the flash tank 160 and the economizer 170 are connected to the evaporator 210 via a third throttle valve 220. Specifically, the output of the flash tank 160 and the output of the economizer 170 are not directly connected to the input of the evaporator 210. Instead, the refrigerant is first fed to the input of the third throttle valve 220. After throttling and reducing the pressure of the refrigerant through the third throttle valve 220, the refrigerant flows into the evaporator 210 from the output of the third throttle valve 220. The presence of the third throttle valve 220 ensures that the refrigerant output from the flash tank 160 and the economizer 170 undergoes uniform throttling before entering the evaporator 210. Regardless of the system's operating mode, the refrigerant parameters entering the evaporator 210 can be precisely controlled by adjusting the opening of the third throttle valve 220. This prevents fluctuations in the heat exchange efficiency of the evaporator 210 caused by unstable refrigerant conditions, thereby enhancing the operational stability of the entire system.

[0050] In one embodiment, Figure 2 As shown, the multi-operation mode high-temperature heat pump system further includes a heat load module 230 , which performs heat exchange with the condenser 130 , and is used to provide heat energy to external user equipment.

[0051] In this embodiment, the heat load module 230 exchanges heat with the condenser 130. Specifically, the heat load module 230 typically takes the form of a heat exchanger, connected to the condenser 130 via a pipeline, forming a closed heat exchange loop. Within this loop, the heat released by the refrigerant in the condenser 130 enters the heat load module 230, where it transfers the heat to a heat medium (such as water or thermal oil) within the heat load module 230. The heat medium absorbs the heat, raising its temperature. The heat is then transferred to external user equipment through a circulation system, providing the required thermal energy. The refrigerant, having released its heat, continues to circulate within the system, participating in subsequent compression, condensation, throttling, and evaporation processes. Specifically, when the high-temperature, high-pressure gaseous refrigerant enters the condenser 130 from the output of the high-pressure compressor 110, it exchanges heat with the external environment within the condenser 130, releasing a significant amount of heat and converting a portion of its gaseous state into a liquid state. At this point, the heat load module 230 and the condenser 130 are engaged in heat exchange. The heat medium flows in the pipe of the heat load module 230, continuously absorbing the heat released by the refrigerant, and the temperature gradually increases.

[0052] In one embodiment, Figure 3 , the heat load module 230 includes a heat exchange component 231, a third solenoid valve 232, a fourth solenoid valve 233 and a heat storage component 234;

[0053] The heat exchange component 231 exchanges heat with the condenser 130. The input end of the heat exchange component 231 is connected to an external water source, and the output end of the heat exchange component 231 is respectively connected to one end of the third solenoid valve 232 and one end of the fourth solenoid valve 233. The other end of the third solenoid valve 232 is connected to the heat storage component 234, and the other end of the fourth solenoid valve 233 is connected to an external user device.

[0054] Heat exchange assembly 231 is the core component for heat exchange within heat load module 230, performing heat exchange with condenser 130. When high-temperature, high-pressure gaseous refrigerant enters condenser 130 from high-pressure compressor 110, it releases a significant amount of heat. Heat exchange assembly 231, positioned adjacent to condenser 130, absorbs this heat from the refrigerant through heat conduction and convection. Furthermore, the input of heat exchange assembly 231 is connected to an external water source. When external water (such as tap water or industrial circulating water) flows into heat exchange assembly 231, it exchanges heat with components within heat exchange assembly 231 that have absorbed heat from condenser 130, raising the water temperature and generating high-temperature steam. This design fully utilizes the heat released by condenser 130. Specifically, heat exchange assembly 231 can be a heat exchange pipe network tightly connected to condenser 130 to absorb the heat released by condenser 130.

[0055] Heat storage assembly 234 is connected to the output end of heat exchange assembly 231 via third solenoid valve 232. Heat storage assembly 234 uses, but is not limited to, inorganic hydrated salts or mineral oils for thermal energy storage. When third solenoid valve 232 is opened, high-temperature steam flows into heat storage assembly 234. The heat storage medium (such as inorganic hydrated salts or mineral oil) absorbs heat from the high-temperature steam, raising its own temperature and undergoing physical or chemical changes (such as dehydration of inorganic hydrated salts), storing the heat as latent heat or sensible heat. When the stored heat is needed, the heat storage medium releases the heat through the reverse process, transferring it back to a heat medium (such as water), which then transmits the heat to external user equipment through a circulation system.

[0056] In one embodiment, the multi-operating mode high-temperature heat pump system further includes a controller, which is connected to the control ends of the first solenoid valve 140 and the second solenoid valve 150; in the energy efficiency ratio priority operating mode, the controller controls the first solenoid valve 140 to open and controls the second solenoid valve 150 to close; in the heating amount priority operating mode, the controller controls the first solenoid valve 140 to close and controls the second solenoid valve 150 to open.

[0057] The controller is used to control the opening and closing of the first solenoid valve 140 and the second solenoid valve 150 to switch between different operating modes.

[0058] like Figure 4As shown, in the energy efficiency ratio priority operation mode (high energy efficiency ratio operation mode), the controller ( Figure 4 The controller (not shown) controls the first solenoid valve 140 to open and the second solenoid valve 150 to close. The first throttle valve 180 is used for preliminary throttling and cooling before entering the flash tank 160. The saturated gas in the flash tank 160 enters the air supply port of the high-pressure compressor, and the saturated liquid in the flash tank 160 enters the third throttle valve 220 and enters the evaporator 210 after throttling. The pressure in the flash tank 160 is controlled by the first throttle valve 180. Further, the controller adjusts the opening of the first throttle valve 180 to adjust the internal pressure of the flash tank 160 to maintain it at a preset flash tank target pressure. The preset flash tank target pressure is determined based on the condenser pressure and the evaporator pressure. Specifically, a pressure sensor can be set in the flash tank 160 to obtain the pressure value in the flash tank 160. The controller uses a PID pressure control algorithm to control the opening of the first throttle valve 180 to maintain the pressure in the tank at the preset flash tank target pressure. Specifically, the preset flash tank target pressure = (condenser pressure * evaporator pressure) 1 / 2 .

[0059] like Figure 5 As shown, in the heating priority operation mode (high heating operation mode), the controller ( Figure 5 A controller (not shown) controls the closing of first solenoid valve 140 and the opening of second solenoid valve 150. Second throttle valve 190 initially throttles and cools the refrigerant before it enters economizer 170. The gas generated by economizer 170 enters the low-pressure compressor air supply port. The cooled refrigerant in economizer 170 enters third throttle valve 220 and, after throttling, enters evaporator 210. The opening degree of second throttle valve 190 determines the refrigerant mass flow rate passing through second throttle valve 190 and the mass flow rate entering the low-pressure compressor air supply line.

[0060] like Figure 4 and Figure 5 As shown, in one embodiment, the third solenoid valve 232 and the fourth solenoid valve 233 included in the heat load module are also controlled by the controller. In the pure heat storage mode, the controller controls the third solenoid valve 232 to open and controls the fourth solenoid valve 233 to close; at this time, high-temperature steam enters the heat storage component 234 through the third solenoid valve 232 for heat storage; in the heat extraction mode, the controller controls the third solenoid valve 232 to close and controls the fourth solenoid valve 233 to open, and at this time, the high-temperature steam transfers heat to the user through the fourth solenoid valve 233.

[0061] In one embodiment, the controller is further configured to adopt an energy efficiency priority operation mode when the compressor driving power is gray electricity; and adopt a heating amount priority operation mode when the compressor driving power is green electricity.

[0062] Gray power generally refers to electricity generated from traditional fossil fuels, such as coal, oil, and natural gas. This type of power generation emits significant amounts of greenhouse gases, including carbon dioxide, during the production process, significantly impacting the environment. While gray power generation costs are relatively stable, its price can be affected by fluctuations in the energy market. From an energy efficiency perspective, traditional fossil fuel power generation involves significant energy losses, resulting in limited overall energy conversion efficiency.

[0063] Green electricity refers to electricity generated from renewable energy sources, including solar, wind, hydro, and biomass. Green electricity is clean, environmentally friendly, and renewable. It produces little or no greenhouse gas emissions during the power generation process, making it far more environmentally friendly than gray electricity. However, green electricity generation is intermittent and unstable. For example, solar power generation depends on the duration and intensity of sunlight, while wind power generation is significantly affected by wind speed and direction. To fully utilize green electricity, appropriate energy storage equipment is required to balance fluctuations in power supply and demand.

[0064] When the controller detects that the compressor drive power is from grey electricity, it activates the energy efficiency ratio (EER) priority mode. EER is a key performance metric for heat pump systems, indicating the amount of cooling or heating generated per unit of electrical energy input. In EER priority mode, the system optimizes operating parameters of various components, such as compressor speed, throttle valve opening, and heat exchanger efficiency, to maximize EER. This means the system minimizes electricity consumption while meeting basic production needs, improving energy efficiency. The advantage of EER priority mode is that it significantly reduces system electricity consumption and operating costs. In production scenarios where grey electricity prices are high or energy costs are sensitive, this mode can bring significant economic benefits to businesses. Furthermore, by improving energy efficiency, it reduces dependence on traditional fossil fuels and reduces greenhouse gas emissions, offering significant environmental benefits. For example, in industrial processes where heat demand is relatively stable but energy costs are minimized, EER priority mode is a very suitable option.

[0065] When the controller detects that the compressor drive power is green electricity, it activates the heating priority mode. Because green electricity is clean and renewable, and because it may be in excess during power generation or require rapid consumption, the heating priority mode can fully utilize green electricity and quickly generate large amounts of heat. This mode prioritizes meeting the system's heating needs, maximizing heating capacity while ensuring safe and stable system operation. The advantage of the heating priority mode is that it fully utilizes green electricity, enabling rapid heating to meet emergency or large-scale heating needs during production. Furthermore, by integrating with thermal energy storage, it effectively addresses the intermittent and unstable nature of green electricity, improving energy efficiency. In production scenarios with high heat demands and the desire to utilize clean energy, such as solar thermal systems and biomass thermal systems, the heating priority mode can fully leverage the advantages of green electricity and achieve a green and efficient heat supply. For example, in large industrial drying plants, where materials need to be dried quickly, the heating priority mode can quickly provide sufficient heat, improving production efficiency.

[0066] The technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0067] The above embodiments merely illustrate several implementation methods of the present application. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art may make various modifications and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present application. Therefore, the scope of protection of the present application shall be determined by the appended claims.

Claims

1. A high-temperature heat pump system with multiple operating modes, characterized in that: The system includes a high-pressure compressor, a low-pressure compressor, a condenser, a first solenoid valve, a second solenoid valve, a flash tank, an economizer, a first throttle valve, a second throttle valve, and an evaporator; The output end of the low-pressure compressor is connected to the input end of the high-pressure compressor, the output end of the high-pressure compressor is connected to the input end of the condenser, the output end of the condenser is respectively connected to one end of the first solenoid valve and one end of the second solenoid valve, the other end of the first solenoid valve is connected to the input end of the flash tank through the first throttle valve, the exhaust port of the flash tank is connected to the air supply port of the high-pressure compressor, the output end of the flash tank is connected to the input end of the evaporator, the other end of the second solenoid valve is respectively connected to the input end of the second throttle valve and the input end of the economizer, the output end of the second throttle valve is connected to the air supply port of the low-pressure compressor, the output end of the economizer is connected to the input end of the evaporator, and the output end of the evaporator is connected to the input end of the low-pressure compressor; The refrigerant after the pressure drop through the second throttle valve exchanges heat with the refrigerant in the economizer and then flows into the air supply port of the low-pressure compressor.

2. The system according to claim 1, wherein: It also includes a third throttle valve; the flash tank and the economizer are connected to the evaporator through the third throttle valve.

3. The system according to claim 1, wherein: It also includes a heat load module, which performs heat exchange with the condenser and is used to provide heat energy to external user equipment.

4. The system according to claim 3, characterized in that The heat load module includes a heat exchange component, a third solenoid valve, a fourth solenoid valve and a heat storage component; The heat exchange component exchanges heat with the condenser, the input end of the heat exchange component is connected to an external water source, the output end of the heat exchange component is respectively connected to one end of the third solenoid valve and one end of the fourth solenoid valve, the other end of the third solenoid valve is connected to the heat storage component, and the other end of the fourth solenoid valve is connected to the external user equipment.

5. The system according to claim 4, characterized in that The heat storage component includes a heat storage component using inorganic hydrated salt or a heat storage component using mineral oil.

6. The system according to claim 1, wherein: Also included is a controller connected to the control ends of the first solenoid valve and the second solenoid valve; In the energy efficiency ratio priority operation mode, the controller controls the first solenoid valve to open and controls the second solenoid valve to close; In the heating amount priority operation mode, the controller controls the first solenoid valve to be closed and controls the second solenoid valve to be open.

7. The system according to claim 6, characterized in that The controller is also connected to the first throttle valve; The controller adjusts the opening of the first throttle valve to adjust the internal pressure of the flash tank to maintain a preset flash tank target pressure, where the preset flash tank target pressure is determined based on a condenser pressure and an evaporator pressure.

8. The system according to claim 7, characterized in that The controller is further configured to adjust the opening of the first throttle valve so as to adopt a PID pressure control algorithm to adjust the internal pressure of the flash tank to maintain it at a preset flash tank target pressure.

9. The system according to claim 6, 7 or 8, characterized in that: The controller is further configured to adopt an energy efficiency ratio priority operation mode when the compressor driving power is gray electricity; and adopt a heating amount priority operation mode when the compressor driving power is green electricity.

10. The system according to claim 4, wherein: Also included is a controller connected to the control ends of the first solenoid valve, the second solenoid valve, the third solenoid valve, and the fourth solenoid valve; In the energy efficiency ratio priority operation mode, the controller controls the first solenoid valve to open and controls the second solenoid valve to close; In the heating priority operation mode, the controller controls the first solenoid valve to close and controls the second solenoid valve to open; In the pure heat storage mode, the controller controls the third solenoid valve to open and controls the fourth solenoid valve to close; In the heat extraction mode, the controller controls the third solenoid valve to close and controls the fourth solenoid valve to open.

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