A supercooler-based heat recovery system and air conditioner water heater all-in-one machine

Abstract

This utility model provides a heat recovery system based on a subcooler and an integrated air conditioning and hot water unit, including: a compression module, a first heat exchanger, a subcooler, a second heat exchanger, and a water tank; the first heat exchanger, subcooler, and second heat exchanger are connected in series, and the compression module is connected to the first and second heat exchangers; the water tank is connected to the subcooler, and the subcooler exchanges heat with the refrigerant condensed by the first or second heat exchanger to transfer heat to the water tank. This utility model, by connecting the first heat exchanger, subcooler, and second heat exchanger in series, allows the first heat exchanger to act as a condenser and the second heat exchanger as an evaporator during the cooling process, and the second heat exchanger to act as a condenser and the first heat exchanger as an evaporator during the heating process, thus separating the condenser and subcooler and improving the system's energy efficiency ratio; by connecting the subcooler to the water tank, the air conditioning and hot water systems are integrated, meeting users' multiple needs for cooling, heating, and hot water supply.

Description

Technical Field

[0001] This utility model relates to the field of compressor heat recovery technology, and in particular to a heat recovery system based on a subcooler and an integrated air conditioning and hot water unit. Background Technology

[0002] In the field of modern air conditioning system technology, the subcooling process is a core element for improving system energy efficiency and reliability, which has attracted much attention. By subcooling the refrigerant, its temperature can be effectively reduced, so that the refrigerant has a higher latent heat when it enters the evaporator. This allows the refrigerant to absorb more heat during the evaporation process, significantly improving the cooling efficiency of the system and enhancing the heat exchange capacity of the evaporator. Maintaining a certain degree of subcooling can also ensure that the refrigerant does not flash before entering the throttling valve, ensuring the reliable operation of the throttling device and greatly improving the overall operational stability of the system.

[0003] Furthermore, during the subcooling process, the refrigerant exchanges heat with the subcooler, allowing the subcooler to gain heat. If this heat can be effectively utilized through a heat recovery device, it can be used to supply hot water or provide auxiliary heating, which is significant for improving the overall system's energy efficiency and achieving energy conservation and emission reduction goals. However, in current traditional air conditioning systems, the condensation and subcooling processes are generally integrated into a single heat exchanger. While this integrated design simplifies the system structure and reduces initial assembly complexity to some extent, it has significant drawbacks. For example, because the condensation and subcooling processes have different temperature and pressure control requirements, sharing the same heat exchanger makes it difficult to achieve precise temperature and pressure control for both processes. This leads to a decrease in the system's energy efficiency ratio, preventing the full realization of the air conditioning system's energy-saving potential and limiting the improvement of heat recovery efficiency, thus failing to meet the growing demand for high-efficiency and energy-saving air conditioning products. Utility Model Content

[0004] This utility model provides a heat recovery system based on a subcooler and an integrated air conditioning and hot water unit, aiming to solve the problem of low system energy efficiency caused by the integration of subcooling and condensation on the same heat exchanger in traditional air conditioners.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, this utility model provides a heat recovery system based on a subcooler, comprising: a compression module, a first heat exchanger, a subcooler, a second heat exchanger, and a water tank; the first heat exchanger, the subcooler, and the second heat exchanger are connected in series, the compression module is connected to the first heat exchanger and the second heat exchanger, and the compression module is used to compress gaseous refrigerant; the water tank is connected to the subcooler, and the subcooler exchanges heat with the refrigerant after it has been condensed by the first heat exchanger or the second heat exchanger, so as to transfer heat to the water tank.

[0006] A first check valve is provided between the second heat exchanger and the subcooler, and the flow direction of the first check valve is from the second heat exchanger to the subcooler.

[0007] A heating expansion valve is provided between the first heat exchanger and the subcooler. When the compression module is operating in heating mode, the refrigerant flows from the compression module through the second heat exchanger, the first one-way valve, the subcooler, the heating expansion valve, and the first heat exchanger before returning to the compression module.

[0008] A second one-way valve is provided between the first heat exchanger and the subcooler, and the flow direction of the second one-way valve is from the first heat exchanger to the subcooler.

[0009] A refrigeration expansion valve is provided between the second heat exchanger and the subcooler; when the compressor is running in refrigeration mode, the refrigerant flows from the compression module through the first heat exchanger, the second one-way valve, the subcooler, the refrigeration expansion valve, and the second heat exchanger in sequence, and then flows back to the compression module.

[0010] A first water pump is provided between the water tank and the subcooler; the two ends of the first water pump are respectively connected to the water inlet of the water tank and the water outlet of the subcooler, and are used to drive hot water from the subcooler into the water tank.

[0011] The outlet of the water tank is connected to the inlet of the subcooler.

[0012] The compression module includes a compressor and a gas-liquid separator; the exhaust pipe of the compressor is connected to the second heat exchanger and the first heat exchanger, and one end of the gas-liquid separator is connected to the intake pipe of the compressor, and the other end is connected to the second heat exchanger and the first heat exchanger.

[0013] It also includes: a four-way valve; the four-way valve has four ports, which are respectively connected to the exhaust pipe of the compressor, the end of the first heat exchanger away from the subcooler, the end of the second heat exchanger away from the subcooler, and the end of the gas-liquid separator away from the compressor.

[0014] Secondly, this utility model embodiment provides an integrated air conditioning and hot water unit, including the aforementioned heat recovery system based on a subcooler.

[0015] The beneficial effects of this utility model compared with the prior art are as follows: By connecting the first heat exchanger, the subcooler, and the second heat exchanger in series, the first heat exchanger acts as a condenser and the second heat exchanger as an evaporator during the cooling process, and the second heat exchanger acts as a condenser and the first heat exchanger as an evaporator during the heating process. This achieves the separation of the condenser and the subcooler, which helps to achieve precise control of the temperature and pressure during the condensation and subcooling processes, thereby significantly improving the condensation efficiency and subcooling efficiency. It also achieves efficient recovery of the heat released by the refrigerant during the subcooling process, effectively improving the system's energy utilization rate and energy efficiency ratio. By connecting the subcooler to the water tank, the air conditioning and hot water systems are integrated, meeting the user's multiple needs for cooling, heating, and hot water supply, and further improving the cost-effectiveness of the air conditioning products.

[0016] The above description is only an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model, it can be implemented according to the contents of the specification. In order to make the above and other objects, features and advantages of this utility model more obvious and understandable, the following are preferred embodiments, which are described in detail below. Attached Figure Description

[0017] Figure 1 A schematic diagram of the overall structure of a heat recovery system based on a subcooler provided for an embodiment of this utility model; Figure 2 A schematic diagram of refrigerant flow in a refrigeration mode of a heat recovery system based on a subcooler, provided for an embodiment of this utility model; Figure 3 A schematic diagram of refrigerant flow in heating mode of a heat recovery system based on a subcooler, provided for an embodiment of this utility model; Figure 4 A schematic diagram of the connection structure of a four-way valve in the refrigeration mode of a heat recovery system based on a subcooler, provided for an embodiment of this utility model; Figure 5 This is a schematic diagram of the connection structure of a four-way valve in the heating mode of a heat recovery system based on a subcooler, provided as an embodiment of this utility model.

[0018] Figure label: 1. Compression module; 11. Compressor; 12. Gas-liquid separator; 2. First heat exchanger; 21. Finned heat exchanger; 22. Variable frequency fan; 3. Subcooler; 4. Second heat exchanger; 5. Water tank; 6a. First check valve; 6b. Second check valve; 7a. Heating expansion valve; 7b. Cooling expansion valve; 8a. First water pump; 8b. Second water pump; 9. Four-way valve. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0020] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0021] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0022] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0023] Example 1 Please see Figure 1-5 This utility model provides a heat recovery system based on a subcooler, including: a compression module 1, a first heat exchanger 2, a subcooler 3, a second heat exchanger 4, and a water tank 5; the first heat exchanger 2, the subcooler 3, and the second heat exchanger 4 are connected in series, the compression module 1 is connected to the first heat exchanger 2 and the second heat exchanger 4, and the compression module 1 is used to compress gaseous refrigerant; the water tank 5 is connected to the subcooler 3, and the subcooler 3 exchanges heat with the refrigerant after it has been condensed by the first heat exchanger 2 or the second heat exchanger 4, so as to transfer heat to the water tank 5.

[0024] The heat recovery system based on a subcooler in this embodiment connects the first heat exchanger 2, the subcooler 3, and the second heat exchanger 4 in series. During the cooling process, the first heat exchanger 2 acts as a condenser and the second heat exchanger 4 acts as an evaporator; during the heating process, the second heat exchanger 4 acts as a condenser and the first heat exchanger 2 acts as an evaporator. This separation of the condenser and subcooler 3 facilitates precise control of temperature and pressure during condensation and subcooling, significantly improving condensation and subcooling efficiency. It also enables efficient recovery of heat released by the refrigerant during subcooling, effectively enhancing the system's energy utilization rate and energy efficiency ratio. Furthermore, by connecting the subcooler 3 to the water tank 5, the air conditioning and hot water systems are integrated, meeting users' multiple needs for cooling, heating, and hot water supply, further improving the cost-effectiveness of the air conditioning product.

[0025] Understandably, when the compression module 1 operates in cooling mode, the high-temperature, high-pressure refrigerant gas discharged from the compression module 1 enters the first heat exchanger 2 and condenses into a saturated liquid. The saturated liquid enters the subcooler 3 for further cooling, achieving subcooling of the refrigerant. At the same time, the heat exchange with the subcooler 3 allows the refrigerant to heat water and store it in the user's water tank 5. The subcooled refrigerant liquid enters the second heat exchanger 4 for evaporation, providing cooling for the user. The evaporated refrigerant gas then re-enters the compression module 1 for compression, completing the cycle.

[0026] Understandably, when the compression module 1 is operating in heating mode, the high-temperature, high-pressure refrigerant gas discharged from the compression module 1 enters the second heat exchanger 4 and condenses into a saturated liquid. The saturated liquid enters the subcooler 3 for further cooling, achieving subcooling of the refrigerant. At the same time, the heat exchange with the subcooler 3 allows the refrigerant to heat water and store it in the user's water tank 5. The subcooled refrigerant liquid enters the first heat exchanger 2 for evaporation, providing heat to the user. The evaporated refrigerant gas then re-enters the compression module 1 for compression, completing the cycle.

[0027] Specifically, the first heat exchanger 2 is an air-cooled heat exchanger. In this embodiment, the first heat exchanger 2 includes a finned heat exchanger 21 and a variable frequency fan 22 disposed on one side of the finned heat exchanger 21. The first heat exchanger 2 releases heat in cooling mode and absorbs heat in heating mode. More specifically, when the system is operating in cooling mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compression module 1 first enters the finned heat exchanger 21. At this time, the variable frequency fan 22 starts, accelerating the airflow. The finned heat exchanger 21 forces the refrigerant to undergo convective heat exchange with the air, thereby causing the high-temperature gaseous refrigerant to gradually release heat and condense into a medium-temperature, high-pressure liquid refrigerant. Subsequently, the liquid refrigerant flows into the subcooler 3 for further cooling. In heating mode, the first heat exchanger 2 operates as an evaporator. Low-temperature, low-pressure refrigerant liquid absorbs heat from the surrounding environment in the finned heat exchanger 21, evaporating into a gaseous state. The variable frequency fan 22 adjusts the airflow to ensure the heat exchange efficiency of the evaporator. Throughout the process, the variable frequency fan 22 can dynamically adjust its speed according to the system load or user needs, achieving precise airflow control. For example, when the ambient temperature is high or the system load is large, the variable frequency fan 22 increases its speed to enhance the heat exchange effect; conversely, it decreases its speed to reduce energy consumption. The variable frequency fan 22 not only accelerates the refrigerant condensation effect but also establishes an intelligent adjustment mechanism for the first heat exchanger 2, enabling it to optimize operation according to actual working conditions and significantly improving the system's energy efficiency ratio.

[0028] Specifically, the second heat exchanger 4 is a water-cooled heat exchanger. In this embodiment, the second heat exchanger 4 is a shell-and-tube heat exchanger. The second heat exchanger 4 absorbs heat in cooling mode and releases heat in heating mode. More specifically, in cooling mode, the low-temperature, high-pressure refrigerant liquid, further cooled by the subcooler 3, enters the shell-and-tube heat exchanger, allowing the refrigerant to flow within it and exchange heat with the cooling water. The refrigerant absorbs heat from the cooling water and evaporates into a low-temperature, low-pressure gaseous refrigerant, providing cooling for the user. In heating mode, the high-temperature, high-pressure gaseous refrigerant enters the shell-and-tube heat exchanger and exchanges heat with the water within it, condensing into a liquid state. The shell-and-tube heat exchanger has a large heat exchange area and excellent heat transfer performance, ensuring efficient heat exchange while achieving precise control of the evaporation and condensation processes. In addition, in cooling mode, water cooling has higher heat exchange efficiency than air cooling, which can more effectively reduce the refrigerant temperature and improve the cooling capacity of the system; and the shell and tube heat exchanger has a compact structure, high reliability, and convenient maintenance, which reduces the operating cost of the system.

[0029] Specifically, a first one-way valve 6a is provided between the second heat exchanger 4 and the subcooler 3. The flow direction of the first one-way valve 6a is from the second heat exchanger 4 to the subcooler 3. It can be understood that the first one-way valve 6a has a flow direction control function. When the compression module 1 is operating in heating mode, the high-temperature and high-pressure gaseous refrigerant is discharged from the compression module 1 and enters the second heat exchanger 4 for condensation. The condensed liquid refrigerant flows to the subcooler 3 through the first one-way valve 6a. Since the flow direction of the first one-way valve 6a is from the second heat exchanger 4 to the subcooler 3, it prevents the refrigerant from flowing in reverse, ensuring that the refrigerant can flow along a predetermined path in heating mode. During the heat exchange with the subcooler 3, the refrigerant is further cooled, and the released heat is used to heat the water in the water tank 5. By setting the first one-way valve 6a, the refrigerant can flow in one direction in the heating mode, ensuring the normal operation of the system, avoiding refrigerant backflow, reducing energy loss, and improving the system's energy efficiency. Compared with the traditional heat recovery system that uses multiple four-way valves 9 and heat exchangers that integrate condensation and subcooling functions, the application of the first one-way valve 6a simplifies the system structure and reduces costs.

[0030] Specifically, a heating expansion valve 7a is provided between the first heat exchanger 2 and the subcooler 3. When the compression module 1 is operating in heating mode, the refrigerant flows from the compression module 1 through the second heat exchanger 4, the first one-way valve 6a, the subcooler 3, the heating expansion valve 7a, and the first heat exchanger 2 before returning to the compression module 1. The heating expansion valve 7a is a device used to regulate the refrigerant flow rate and pressure. In this embodiment, the heating expansion valve 7a throttles and reduces the pressure of the refrigerant in heating mode, enabling the refrigerant to effectively absorb heat in the first heat exchanger 2 and ensuring that the refrigerant fully evaporates in the first heat exchanger 2. More specifically, in heating mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compression module 1 first enters the second heat exchanger 4, where it condenses into a liquid state. The liquid refrigerant then flows through the first one-way valve 6a to the subcooler 3, where it is further cooled, and the released heat is used to heat the water in the water tank 5. When the subcooled liquid refrigerant reaches the heating expansion valve 7a, due to the throttling effect of the valve, the pressure and temperature of the refrigerant drop sharply, becoming a low-temperature, low-pressure gas-liquid mixture. This low-temperature, low-pressure refrigerant enters the first heat exchanger 2, absorbs heat from the external environment, and evaporates into a gaseous refrigerant. Finally, the gaseous refrigerant flows back to the compression module 1, completing the heating cycle. The heating expansion valve 7a enables precise control of the refrigerant flow and pressure during heating, ensuring efficient system operation in heating mode. By throttling and reducing the pressure of the refrigerant, it allows the refrigerant to effectively absorb external heat in the first heat exchanger 2, further improving the system's heating capacity.

[0031] Specifically, a second one-way valve 6b is provided between the first heat exchanger 2 and the subcooler 3. The flow direction of the second one-way valve 6b is from the first heat exchanger 2 to the subcooler 3. When the system is running in cooling mode, the high-temperature and high-pressure gaseous refrigerant discharged from the compression module 1 enters the first heat exchanger 2 for condensation. The condensed liquid refrigerant flows to the subcooler 3 through the second one-way valve 6b. Since the flow direction of the second one-way valve 6b is from the first heat exchanger 2 to the subcooler 3, it ensures that the refrigerant can flow smoothly from the first heat exchanger 2 to the subcooler 3 in cooling mode, avoiding reverse flow of the refrigerant. During the heat exchange with the subcooler 3, the refrigerant is further cooled, and the released heat is used to heat the water in the water tank 5. The second one-way valve 6b ensures unidirectional flow of refrigerant in refrigeration mode, optimizes system operating efficiency, avoids refrigerant backflow, reduces energy loss, and improves system energy efficiency. Compared with traditional heat recovery systems that use multiple four-way valves 9 and heat exchangers that integrate condensation and subcooling functions, the application of the second one-way valve 6b simplifies the system structure and reduces costs.

[0032] Specifically, a refrigeration expansion valve 7b is provided between the second heat exchanger 4 and the subcooler 3. When the compressor operates in refrigeration mode, the refrigerant flows from the compression module 1 through the first heat exchanger 2, the second one-way valve 6b, the subcooler 3, the refrigeration expansion valve 7b, and the second heat exchanger 4 before returning to the compression module 1. The refrigeration expansion valve 7b is a device used to regulate the refrigerant flow and pressure. In this embodiment, the refrigeration expansion valve 7b throttles and reduces the pressure of the refrigerant in refrigeration mode, enabling the refrigerant to effectively absorb heat in the second heat exchanger 4 and ensuring that the refrigerant fully evaporates in the second heat exchanger 4. More specifically, in cooling mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compression module 1 first enters the first heat exchanger 2, where it condenses into a liquid state. The liquid refrigerant then flows through the second one-way valve 6b to the subcooler 3, where it is further cooled, and the released heat is used to heat the water in the water tank 5. When the subcooled liquid refrigerant reaches the expansion valve 7b, due to the throttling effect of the expansion valve 7b, the pressure and temperature of the refrigerant drop sharply, becoming a low-temperature, low-pressure gas-liquid mixture. This low-temperature, low-pressure refrigerant then enters the second heat exchanger 4, where it absorbs heat from the cooling water and evaporates into a gaseous refrigerant, thus providing cooling capacity to the user. The expansion valve 7b enables precise control of the refrigerant flow and pressure during the cooling process, ensuring efficient system operation in cooling mode. By throttling and reducing the pressure of the refrigerant, it allows the refrigerant to effectively absorb external heat in the second heat exchanger 4, further improving the system's cooling capacity.

[0033] Specifically, the first one-way valve 6a is connected in parallel with the refrigeration expansion valve 7b. It can be understood that the flow directions of the first one-way valve 6a and the refrigeration expansion valve 7b are opposite. During system operation, the parallel structure of the first one-way valve 6a and the refrigeration expansion valve 7b enables intelligent switching of the refrigerant flow direction between cooling and heating modes. When the system is in cooling mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compression module 1 condenses into a liquid state in the first heat exchanger 2, and then flows to the subcooler 3 through the second one-way valve 6b. The subcooled refrigerant liquid needs to undergo throttling and pressure reduction before entering the second heat exchanger 4 for evaporation. Since the flow direction of the first one-way valve 6a is opposite to the refrigerant flow direction, the first one-way valve 6a is in the closed state, and the refrigerant can only undergo throttling and pressure reduction through the refrigeration expansion valve 7b before entering the second heat exchanger 4. In heating mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compression module 1 condenses into a liquid state in the second heat exchanger 4. Due to the high resistance of the refrigeration expansion valve 7b, the refrigerant cannot pass through the refrigeration expansion valve 7b. Instead, it flows through the first one-way valve 6a to the subcooler 3, and then enters the first heat exchanger 2 after being throttled and depressurized by the heating expansion valve 7a. The parallel design of the first one-way valve 6a and the refrigeration expansion valve 7b simplifies the system structure, reduces costs, and improves system reliability. Compared with traditional heat recovery systems that use multiple four-way valves 9 and heat exchangers that integrate condensation and subcooling functions, this design reduces the number of four-way valves 9, lowers flow resistance, thereby reducing energy loss and improving the system's energy efficiency ratio. In addition, this design simplifies system control, allowing for active refrigerant flow in both cooling and heating modes without changing or adjusting the flow direction of the first one-way valve 6a or the refrigeration expansion valve 7b, thus improving the system's operational convenience.

[0034] Specifically, the refrigeration expansion valve 7b is an electronic expansion valve. An electronic expansion valve is an expansion valve whose opening is controlled by electronic signals. In this embodiment, the electronic expansion valve, as the refrigeration expansion valve 7b, can adjust the refrigerant flow rate in real time according to system operating conditions. More specifically, the electronic expansion valve is equipped with a temperature sensing bulb. In the refrigeration expansion valve 7b, the temperature sensing bulb is used to sense the refrigerant temperature at the output end of the first heat exchanger 2, and the electronic expansion valve has the function of automatically adjusting the valve opening, ensuring that the refrigerant evaporates fully in the first heat exchanger 2, improving the heating efficiency of the system. In cooling mode, when the compression module 1 is running, the electronic expansion valve can adjust the valve opening in real time according to parameters such as system load, refrigerant temperature and pressure at the outlet of the second heat exchanger 4. For example, when the system load increases, the electronic expansion valve automatically increases the opening, allowing more refrigerant to enter the second heat exchanger 4 to meet the cooling demand; when the system load decreases, the electronic expansion valve decreases the opening, reducing the refrigerant flow rate and avoiding unnecessary energy consumption. The precise control of the electronic expansion valve allows the refrigerant to fully evaporate in the second heat exchanger 4, improving the system's refrigeration efficiency and significantly enhancing the system's control accuracy and energy efficiency ratio. At the same time, the electronic expansion valve can also quickly respond to changes in system operating conditions, rapidly adjusting the valve opening during system startup, shutdown, or sudden load changes to ensure stable system operation.

[0035] Specifically, the second one-way valve 6b is connected in parallel with the heating expansion valve 7a. It can be understood that the flow directions of the second one-way valve 6b and the heating expansion valve 7a are opposite. During system operation, the parallel structure of the second one-way valve 6b and the heating expansion valve 7a enables intelligent switching of the refrigerant flow direction between heating and cooling modes. When the system is in heating mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compression module 1 condenses into a liquid state in the second heat exchanger 4 and flows to the subcooler 3 through the first one-way valve 6a. The subcooled refrigerant liquid needs to undergo throttling and pressure reduction before entering the first heat exchanger 2 for evaporation. Since the flow direction of the second one-way valve 6b is opposite to the refrigerant flow direction, the second one-way valve 6b is in a closed state, and the refrigerant can only undergo throttling and pressure reduction through the heating expansion valve 7a before entering the first heat exchanger 2. In cooling mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compression module 1 condenses into a liquid state in the first heat exchanger 2. Due to the high resistance of the heating expansion valve 7a, the refrigerant cannot pass through the heating expansion valve 7a. Instead, it flows through the second one-way valve 6b to the subcooler 3, and then, after being throttled and depressurized by the cooling expansion valve 7b, enters the second heat exchanger 4. This parallel structure ensures that the refrigerant can flow along a predetermined path in different modes. The parallel design of the second one-way valve 6b and the heating expansion valve 7a enables the switching of refrigerant flow direction between cooling and heating modes without the need for complex control logic. It also reduces redundant components in the system, lowers costs, and improves system reliability.

[0036] Specifically, the heating expansion valve 7a is an electronic expansion valve. An electronic expansion valve is an expansion valve whose opening is controlled by electronic signals. In this embodiment, the electronic expansion valve, serving as the heating expansion valve 7a, can adjust the refrigerant flow rate in real time according to system operating conditions. More specifically, the electronic expansion valve is equipped with a temperature sensing bulb. In the heating expansion valve 7a, the temperature sensing bulb is used to sense the refrigerant temperature at the output end of the first heat exchanger 2, and the electronic expansion valve has the function of automatically adjusting the valve opening, ensuring that the refrigerant fully evaporates in the first heat exchanger 2, improving the system's heating efficiency. In heating mode, when the compression module 1 is running, the electronic expansion valve adjusts the valve opening in real time according to parameters such as system load, refrigerant temperature and pressure at the outlet of the first heat exchanger 2. For example, when the ambient temperature is low and the system needs to provide more heat, the electronic expansion valve will automatically increase the opening, allowing more refrigerant to enter the first heat exchanger 2 to enhance the heating effect; when the ambient temperature is high or the system load decreases, the electronic expansion valve will decrease the opening, reducing the refrigerant flow rate and avoiding energy waste. Using an electronic expansion valve as the heating expansion valve 7a allows the refrigerant to fully evaporate in the first heat exchanger 2, improving the system's heating efficiency. At the same time, the heating expansion valve 7a can also quickly respond to changes in system operating conditions, rapidly adjusting the valve opening when the system starts up, stops, or experiences sudden load changes, ensuring stable system operation.

[0037] It is understood that, in other embodiments, a thermostatic expansion valve may be used instead of an electronic expansion valve, depending on actual needs. The thermostatic expansion valve can control the valve opening through its own temperature sensing bulb and diaphragm to achieve throttling and pressure reduction control of the refrigerant.

[0038] Specifically, a first water pump 8a is installed between the water tank 5 and the subcooler 3. The two ends of the first water pump 8a are connected to the inlet of the water tank 5 and the outlet of the subcooler 3, respectively, to drive hot water from the subcooler 3 into the water tank 5. When the refrigerant undergoes subcooling in the subcooler 3, it releases heat, which is absorbed by the water in the subcooler 3, raising the water temperature. After the first water pump 8a is turned on, hot water flows out from the outlet of the subcooler 3 and is then transported by the first water pump 8a to the inlet of the water tank 5 for storage, making it available for user use. The stable operation of the first water pump 8a ensures the continuity and stability of the hot water supply, improves the user experience, and utilizes the heat generated by the air conditioner's cooling and heating functions to heat the user's water, improving heat recovery efficiency and energy utilization, thus meeting the market demand for energy-saving and environmentally friendly air conditioning products.

[0039] Specifically, the first water pump 8a is a variable frequency water pump. Through frequency conversion control, the first water pump 8a can automatically adjust its flow rate according to the water temperature of the water tank 5, the system's heat recovery requirements, or the user's water demand. This helps improve energy utilization, avoid resource waste, and reduce system energy consumption. For example, when the water temperature in the water tank 5 reaches the set value, the first water pump 8a reduces its speed, thus reducing energy consumption.

[0040] Specifically, the outlet of water tank 5 is connected to the inlet of subcooler 3. The connection between the outlet of water tank 5 and the inlet of subcooler 3 allows water tank 5 to supply water to subcooler 3, which improves the cooling efficiency of subcooler 3 for refrigerant and shortens the heat exchange path between refrigerant and water, thereby improving heat recovery efficiency. The outlet of subcooler 3 and the inlet of water tank 5 are connected through the first water pump 8a. Because the outlet of water tank 5 and the inlet of subcooler 3 are connected, water tank 5 and subcooler 3 form a complete hot water circulation loop. More specifically, when the system is in cooling or heating mode, the low-temperature water in water tank 5 flows out from the outlet of water tank 5 and is transported through pipes to the inlet of subcooler 3. The refrigerant undergoes subcooling in subcooler 3, releasing heat. At this time, the low-temperature water exchanges heat with the high-temperature refrigerant, absorbing the heat released by the refrigerant, thus raising the water temperature. The heated hot water flows out from the outlet of subcooler 3 and is then pumped back to the inlet of water tank 5 by the first water pump 8a, entering water tank 5 for storage. This cycle continues continuously, causing the water temperature in water tank 5 to gradually rise. The hot water circulation loop achieves a closed-loop hot water system, realizing effective heat recovery and utilization, improving heat recovery efficiency. By directly transporting the low-temperature water from water tank 5 to subcooler 3, the heat released by the refrigerant is fully utilized, reducing heat loss and enabling faster heating of the water in water tank 5 to meet users' hot water needs. Furthermore, the closed-loop connection method makes the system structure more compact, reducing the floor space and lowering installation costs.

[0041] Specifically, water tank 5 is also equipped with a water inlet, through which users can access hot water from water tank 5. When users need hot water, they simply open the water inlet, and the hot water in water tank 5 will flow out under pressure. The water inlet in water tank 5 directly meets users' hot water needs, achieving an integrated design of the air conditioning system and hot water supply. This eliminates the need for additional hot water heating equipment, reducing system production and operating costs, and consequently lowering users' investment and operating expenses. Furthermore, heating hot water using heat recovery technology improves energy efficiency, reduces energy waste, and meets energy conservation and emission reduction requirements.

[0042] Specifically, a second water pump 8b is also provided at the inlet end of the second heat exchanger 4; the second water pump 8b is used to drive external water into the second heat exchanger 4. During system operation, the second water pump 8b can provide cooling water to the second heat exchanger 4. When the system is in cooling mode, the second heat exchanger 4 works as an evaporator and needs to absorb external heat. At this time, the second water pump 8b starts, draws cold water from the external water source, and transports it to the inlet end of the second heat exchanger 4 through pipelines; in the second heat exchanger 4, the cold water exchanges heat with the low-temperature, low-pressure refrigerant. The refrigerant absorbs the heat from the cold water and evaporates into a gaseous state, while the cold water releases heat and its temperature rises; the heated cooling water flows out from the outlet end of the second heat exchanger 4. When the system is in heating mode, the second heat exchanger 4 works as a condenser. At this time, the second water pump 8b starts to draw cooling water from an external water source. The high-temperature and high-pressure refrigerant gas discharged from the compression module 1 directly enters the second heat exchanger 4. Due to the high internal pressure, the refrigerant condenses into a liquid in the second heat exchanger 4, releasing heat to the water flowing through the second heat exchanger 4.

[0043] Specifically, the second water pump 8b is a variable frequency water pump. By setting up the second water pump 8b, sufficient cooling water is ensured for the second heat exchanger 4, guaranteeing the normal operation of the system. Furthermore, the second water pump 8b utilizes variable frequency technology, enabling intelligent adjustment of operating parameters based on system load or cooling water temperature requirements, thus achieving flow regulation and reducing energy consumption. In addition, the variable frequency settings of the first water pump 8a, the second water pump 8b, and the variable frequency fan 22 enable intelligent control of the heat recovery system, further improving the user experience. Specifically, when the system operates in cooling mode, the frequency control of the variable frequency fan 22 and the flow control of the first water pump 8a improve the heat exchange efficiency of the first heat exchanger 2 and the heat recovery efficiency of the subcooler 3, further enhancing the overall energy efficiency. When the system operates in heating mode, since both the condensation and subcooling processes can provide heat to the user, the output of the variable frequency fan 22 and the second water pump 8b can be controlled according to the priority of user needs.

[0044] More specifically, in cooling mode, the frequencies of the variable frequency fan 22 and the first water pump 8a can be adjusted according to the degree of subcooling. In practice, the system acquires the finned liquid tube temperature and condensing pressure of the first heat exchanger 2 and calculates the degree of subcooling of the finned liquid tube; it also acquires the output temperature and condensing pressure of the subcooler 3 and calculates the heat recovery subcooling, thereby controlling the frequencies of the variable frequency fan 22 and the first water pump 8a. For example, by adjusting the frequency of the variable frequency fan 22, the subcooling of the first heat exchanger 2 can be controlled to be around 0°C; by adjusting the frequency of the first water pump 8a, the heat recovery subcooling of the subcooler 3 can be controlled to be between 7 and 9°C.

[0045] More specifically, in heating mode, the frequencies of the second water pump 8b and the first water pump 8a can be adjusted based on the subcooling. In practice, the system obtains the shell-and-tube liquid-tube temperature and condensing pressure of the second heat exchanger 4 to calculate the subcooling, and calculates the heat recovery subcooling based on the output temperature and condensing pressure of the subcooler 3, thereby controlling the frequencies of the second water pump 8b and the first water pump 8a. For example, the frequency of the second water pump 8b is adjusted to keep the subcooling of the second heat exchanger 4 around 0°C; the frequency of the first water pump 8a is adjusted to keep the heat recovery subcooling of the subcooler 3 between 7 and 9°C. If the user's heating demand is high, the frequency of the second water pump 8b is increased to improve the heat exchange efficiency of the second heat exchanger 4, thus providing more heat to the user; if the user's hot water demand is high, the frequency of the first water pump 8a is increased to improve the heat recovery efficiency of the subcooler 3, thereby generating more hot water.

[0046] In a preferred embodiment, the second heat exchanger 4 can be connected to the water tank 5. The water tank 5 provides low-temperature water to the second heat exchanger 4, where the low-temperature water exchanges heat with the refrigerant, raising the water temperature and completing the heating process. The heated water then enters the water tank 5 for storage and is available for user use. This design, connecting the second heat exchanger 4 to the water tank 5, forms a closed-loop heat exchange circuit, preventing heat loss and significantly improving heat recovery efficiency. Simultaneously, it reduces reliance on external water sources and water supply systems, lowering system energy consumption and operating costs.

[0047] Specifically, the compression module 1 includes a compressor 11 and a gas-liquid separator 12. The discharge pipe of the compressor 11 is connected to the second heat exchanger 4 and the first heat exchanger 2. One end of the gas-liquid separator 12 is connected to the intake pipe of the compressor 11, and the other end is connected to the second heat exchanger 4 and the first heat exchanger 2. The gas-liquid separator 12 is used to separate the refrigerant into gas and liquid states, ensuring that the refrigerant entering the compressor is in a gaseous state, preventing liquid refrigerant from entering the compressor 11, avoiding liquid slugging that could damage the compressor, and ensuring the reliability and safety of the heat recovery system.

[0048] Specifically, the heat recovery system based on the subcooler in this embodiment further includes: a four-way valve 9; the four-way valve 9 has four ports, which are respectively connected to the exhaust pipe of the compressor 11, the end of the first heat exchanger 2 away from the subcooler 3, the end of the second heat exchanger 4 away from the subcooler 3, and the end of the gas-liquid separator 12 away from the compressor 11. See also Figure 4-5The four ports are C, D, E, and S. Port C is connected to the end of the first heat exchanger 2 furthest from the subcooler 3; port D is connected to the exhaust pipe of the compressor 11; port E is connected to the end of the second heat exchanger 4 furthest from the subcooler 3; and port S is connected to the end of the gas-liquid separator 12 furthest from the compressor 11. When the compressor module 1 operates in cooling mode, port D is connected to port C, and port E is connected to port S. When the compressor module 1 operates in heating mode, port D is connected to port E, and port C is connected to port S. The four-way valve 9 allows the system to flexibly switch between cooling and heating modes, and integrates the cooling and heating systems into one system, simplifying the system structure. Compared with the traditional dual-system design with separate cooling and heating systems, the application of the four-way valve 9 reduces the number of devices, shrinks the system size, and improves the system's compactness and ease of installation. When the system needs to operate in cooling mode, the high-temperature, high-pressure gaseous refrigerant discharged from compressor 11 enters the four-way valve 9 through port D, and then flows through port C to the first heat exchanger 2 for condensation. The condensed liquid refrigerant then passes through the subcooler 3 and the refrigeration expansion valve 7b in sequence, and enters the second heat exchanger 4 for evaporation. The evaporated low-temperature, low-pressure gaseous refrigerant flows out of the second heat exchanger 4, enters the four-way valve 9 through port E, then flows through port S to the gas-liquid separator 12, and finally returns to compressor 11. When the system needs to operate in heating mode, the high-temperature, high-pressure gaseous refrigerant discharged from compressor 11 enters the four-way valve 9 through port D, and then flows through port E to the second heat exchanger 4 for condensation. The condensed liquid refrigerant then passes through the subcooler 3 and the heating expansion valve 7a in sequence, and enters the first heat exchanger 2 for evaporation. The evaporated low-temperature, low-pressure gaseous refrigerant flows out of the first heat exchanger 2, enters the four-way valve 9 through port C, then flows through port S to the gas-liquid separator 12, and finally returns to compressor 11.

[0049] It is understandable that the compressor 11, gas-liquid separator 12, four-way valve 9, first heat exchanger 2, second one-way valve 6b, heating expansion valve 7a, subcooler 3, first one-way valve 6b, cooling expansion valve 7b, and second heat exchanger 4 are connected by refrigerant pipelines; the subcooler 3, first water pump 8a, and water tank 5 are connected by water pipelines, and the second heat exchanger 4 is connected to an external water source by water pipelines.

[0050] Example 2 Please see Figure 1-5 This utility model provides an integrated air conditioning and hot water unit, including the heat recovery system based on a subcooler as described in Embodiment 1.

[0051] This embodiment of the integrated air conditioning and hot water unit incorporates the heat recovery system based on a subcooler as described in Embodiment 1. It integrates cooling, heating, and hot water supply functions into a single device, meeting diverse user needs and avoiding the redundant construction and energy waste caused by the separation of functions in traditional air conditioning and hot water units. This significantly saves installation space and user investment costs, demonstrating significant market competitiveness and application value. Utilizing the efficient use of subcooling and heating by the heat recovery system, waste heat can be simultaneously converted into hot water during both cooling and heating operations, significantly improving energy efficiency and reducing operating energy consumption. Furthermore, the first water pump 8a, the second water pump 8b, and the variable frequency fan 22 in the subcooler-based heat recovery system can dynamically adjust system operating parameters according to ambient temperature or user needs, ensuring the equipment is always operating at high efficiency. This not only improves cooling and heating efficiency but also ensures a stable hot water supply, enhancing the user experience.

[0052] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A subcooler-based heat recovery system, characterized by, include: The system comprises a compression module, a first heat exchanger, a subcooler, a second heat exchanger, and a water tank. The first heat exchanger, the subcooler, and the second heat exchanger are connected in series. The compression module is connected to the first heat exchanger and the second heat exchanger and is used to compress gaseous refrigerant. The water tank is connected to the subcooler, and the subcooler exchanges heat with the refrigerant after it has been condensed by the first or second heat exchanger to transfer heat to the water tank.

2. The subcooler-based heat recovery system of claim 1, wherein, A first check valve is provided between the second heat exchanger and the subcooler, and the flow direction of the first check valve is from the second heat exchanger to the subcooler.

3. The heat recovery system based on a subcooler according to claim 2, characterized in that, A heating expansion valve is provided between the first heat exchanger and the subcooler; when the compression module is operating in heating mode, the refrigerant flows from the compression module through the second heat exchanger, the first one-way valve, the subcooler, the heating expansion valve, and the first heat exchanger in sequence, and then flows back to the compression module.

4. The subcoiiider-based heat recovery system of claim 1, wherein, A second check valve is provided between the first heat exchanger and the subcooler, and the flow direction of the second check valve is from the first heat exchanger to the subcooler.

5. The heat recovery system based on a subcooler according to claim 4, characterized in that, A refrigeration expansion valve is provided between the second heat exchanger and the subcooler; when the compressor is running in refrigeration mode, the refrigerant flows from the compression module through the first heat exchanger, the second check valve, the subcooler, the refrigeration expansion valve, and the second heat exchanger in sequence, and then flows back to the compression module.

6. The heat recovery system based on a subcooler according to claim 1, characterized in that, A first water pump is also provided between the water tank and the subcooler; the two ends of the first water pump are respectively connected to the water inlet of the water tank and the water outlet of the subcooler, and are used to drive hot water from the subcooler into the water tank.

7. The heat recovery system based on a subcooler according to claim 1, characterized in that, The outlet of the water tank is connected to the inlet of the subcooler.

8. The heat recovery system based on a subcooler according to claim 1, characterized in that, The compression module includes a compressor and a gas-liquid separator; the exhaust pipe of the compressor is connected to the second heat exchanger and the first heat exchanger, one end of the gas-liquid separator is connected to the intake pipe of the compressor, and the other end is connected to the second heat exchanger and the first heat exchanger.

9. The subcoiiier-based heat recovery system of claim 8, wherein, Also includes: Four-way valve; The four-way valve has four ports, which are respectively connected to the exhaust pipe of the compressor, the end of the first heat exchanger away from the subcooler, the end of the second heat exchanger away from the subcooler, and the end of the gas-liquid separator away from the compressor.

10. An integrated air conditioning and hot water unit, characterized in that, Including the heat recovery system based on a subcooler as described in any one of claims 1-9.

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