Heat recovery system based on subcooler and air conditioner and hot water all-in-one machine

Abstract

The embodiment of the invention provides a heat recovery system based on a subcooler and an air conditioner and hot water all-in-one machine. The heat recovery system comprises a compression module, a first heat exchanger, the subcooler, a second heat exchanger and a water tank. The first heat exchanger, the subcooler and the second heat exchanger are sequentially connected in series. The compression module is connected to the first heat exchanger and the second heat exchanger. The water tank is connected to the subcooler, and the subcooler exchanges heat with the refrigerant condensed by the first heat exchanger or the second heat exchanger so as to transfer heat to the water tank. The first heat exchanger, the subcooler and the second heat exchanger are sequentially connected in series, so that the first heat exchanger serves as a condenser and the second heat exchanger serves as an evaporator in the refrigerating process, the second heat exchanger serves as a condenser and the first heat exchanger serves as an evaporator in the heating process, and separation of the condenser and the subcooler is achieved; the energy efficiency ratio of the system is improved; the subcooler is connected with the water tank, so that integration of an air conditioner and a hot water system is achieved, and the multiple requirements of users for refrigeration, heating and hot water supply are met.

Description

Technical Field

[0001] The present invention relates to the technical field of compressor heat recovery, and in particular to a heat recovery system based on a subcooler and an integrated air-conditioning and hot water machine. Background Art

[0002] In the field of modern air-conditioning system technology, the supercooling process has attracted much attention as a core link to improve the energy efficiency and reliability of the system. By supercooling the refrigerant, its temperature can be effectively reduced, so that the refrigerant has a higher latent heat when entering the evaporator, and then absorbs 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 supercooling can also ensure that the refrigerant does not flash before entering the throttle valve, ensuring the reliable operation of the throttling device and greatly improving the overall operational stability of the system.

[0003] In addition, during the supercooling process, the refrigerant will exchange 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 auxiliary heating, which is of great significance to improving the energy utilization rate of the entire system and achieving energy conservation and emission reduction goals. However, the current structural design of traditional air-conditioning systems generally integrates the condensation and supercooling processes within the same heat exchanger. Although this integrated design simplifies the system structure to a certain extent and reduces the complexity of initial assembly, it has obvious disadvantages. For example, due to the different temperature and pressure control requirements for the condensation and supercooling processes, sharing the same heat exchanger will make it difficult to achieve precise temperature and pressure control for the two processes, which in turn reduces the energy efficiency of the system, making it impossible to fully realize the energy-saving potential of the air-conditioning system, and also limits the improvement of heat recovery efficiency, making it difficult to meet the growing demand for high-efficiency and energy-saving air-conditioning products. Summary of the Invention

[0004] The present invention provides a heat recovery system based on a subcooler and an integrated air-conditioning and hot water machine, aiming to solve the problem that in traditional air-conditioning, subcooling and condensing are integrated on the same heat exchanger, resulting in low system energy efficiency.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, an embodiment of the present invention 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 in sequence, the compression module is connected to the first heat exchanger and the second heat exchanger, and the compression module is used to compress the gaseous refrigerant; the water tank is connected to the subcooler, and the subcooler performs heat exchange with the refrigerant condensed by the first heat exchanger or the second heat exchanger to transfer heat to the water tank.

[0007] A first one-way valve is provided between the second heat exchanger and the subcooler, and the flow direction of the first one-way valve is from the second heat exchanger to the subcooler.

[0008] A heating expansion valve is provided between the first heat exchanger and the subcooler; when the compression module operates 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, the first heat exchanger in sequence, and then flows back to the compression module.

[0009] 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.

[0010] A refrigeration expansion valve is provided between the second heat exchanger and the subcooler; when the compressor operates 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, the second heat exchanger in sequence, and then flows back to the compression module.

[0011] A first water pump is provided between the water tank and the subcooler; both ends of the first water pump are respectively connected to the water inlet of the water tank and the water outlet of the subcooler, for driving hot water from the subcooler into the water tank.

[0012] Wherein, the water outlet end of the water tank is connected to the water inlet end of the supercooler.

[0013] Wherein, 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.

[0014] Among them, it also includes: a four-way valve; the four-way valve is provided with four ports, and the four ports 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.

[0015] In a second aspect, an embodiment of the present invention provides an integrated air-conditioning and water-heating machine, comprising the above-mentioned heat recovery system based on a subcooler.

[0016] The beneficial effects of the present invention compared with the prior art are as follows: the present invention realizes the separation of the condenser and the subcooler by connecting the first heat exchanger, the subcooler and the second heat exchanger in series in sequence, so that in the cooling process, the first heat exchanger acts as a condenser and the second heat exchanger acts as an evaporator, and in the heating process, the second heat exchanger acts as a condenser and the first heat exchanger acts as an evaporator, which helps to achieve precise control of the temperature and pressure of the condensation and subcooling processes, thereby greatly improving the condensing efficiency and subcooling efficiency, and also achieving efficient recovery of heat released by the refrigerant in the subcooling process, effectively improving the energy utilization rate and energy efficiency ratio of the system; by connecting the subcooler to the water tank, the integration of the air conditioning and hot water system is realized, meeting the user's multiple needs for cooling, heating and hot water supply, and further improving the cost performance of air-conditioning products.

[0017] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In addition, in order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following preferred embodiments are specifically cited and described in detail as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of the overall structure of a heat recovery system based on a subcooler provided in an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of the refrigerant flow in a refrigeration mode of a heat recovery system based on a subcooler provided by an embodiment of the present invention;

[0020] Figure 3 A schematic diagram of the refrigerant flow in heating mode of a heat recovery system based on a subcooler provided by an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of the connection structure of a four-way valve in a cooling mode of a heat recovery system based on a subcooler provided in an embodiment of the present invention;

[0022] Figure 5 A schematic diagram of the communication structure of a four-way valve in a heating mode of a heat recovery system based on a subcooler provided in an embodiment of the present invention.

[0023] Reference numerals:

[0024] 1. Compression module; 11. Compressor; 12. Gas-liquid separator; 2. First heat exchanger; 21. Fin heat exchanger; 22. Variable frequency fan; 3. Subcooler; 4. Second heat exchanger; 5. Water tank; 6a. First one-way valve; 6b. Second one-way valve; 7a. Heating expansion valve; 7b. Cooling expansion valve; 8a. First water pump; 8b. Second water pump; 9. Four-way valve. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0026] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0027] 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 present invention. As used in the specification and appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0028] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0029] Example 1

[0030] See also Figure 1-5 An embodiment of the present invention provides a heat recovery system based on a subcooler, comprising: 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 in sequence, 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 the gaseous refrigerant; the water tank 5 is connected to the subcooler 3, and the subcooler 3 performs heat exchange with the refrigerant condensed by the first heat exchanger 2 or the second heat exchanger 4 to transfer heat to the water tank 5.

[0031] The heat recovery system based on the subcooler of this embodiment realizes the separation of the condenser and the subcooler 3 by connecting the first heat exchanger 2, the subcooler 3 and the second heat exchanger 4 in series in sequence, so that in the cooling process, the first heat exchanger 2 acts as a condenser and the second heat exchanger 4 acts as an evaporator, and in the heating process, the second heat exchanger 4 acts as a condenser and the first heat exchanger 2 acts as an evaporator, thereby facilitating the precise control of the temperature and pressure of the condensation and subcooling processes, thereby greatly improving the condensation efficiency and subcooling efficiency, and realizing the efficient recovery of the heat released by the refrigerant in the subcooling process, effectively improving the energy utilization rate and energy efficiency ratio of the system; by connecting the subcooler 3 with the water tank 5, the integration of the air conditioning and hot water systems is realized, meeting the user's multiple needs for cooling, heating and hot water supply, and further improving the cost performance of air-conditioning products.

[0032] It can be understood that when the compression module 1 operates in the cooling mode, the high-temperature and high-pressure high-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 to achieve supercooling of the refrigerant. At the same time, the heat of the refrigerant is used to heat water and store it in the user's water tank 5 by heat exchange with the subcooler 3; the supercooled refrigerant liquid enters the second heat exchanger 4 for evaporation to provide cooling for the user; the evaporated refrigerant gas enters the compression module 1 again for compression to complete the cycle.

[0033] It can be understood that when the compression module 1 operates in the heating mode, the compression module 1 discharges high-temperature and high-pressure high-temperature refrigerant gas into the second heat exchanger 4 to condense into a saturated liquid; the saturated liquid enters the subcooler 3 for further cooling to achieve supercooling of the refrigerant. At the same time, the heat of the refrigerant is used to heat water and store it in the user's water tank 5 by heat exchange with the subcooler 3; the supercooled refrigerant liquid enters the first heat exchanger 2 for evaporation to provide heat for the user; the evaporated refrigerant gas enters the compression module 1 again for compression to complete the cycle.

[0034] Specifically, the first heat exchanger 2 is an air-cooled heat exchanger. In this embodiment, the first heat exchanger 2 includes a fin heat exchanger 21 and a variable frequency fan 22 provided on one side of the fin heat exchanger 21. The first heat exchanger 2 releases heat in cooling mode and absorbs heat in heating mode. More specifically, when the system operates in cooling mode, the high-temperature and high-pressure gaseous refrigerant discharged by the compression module 1 first enters the fin heat exchanger 21. At this time, the variable frequency fan 22 starts to accelerate the air flow, and the fin heat exchanger 21 causes the refrigerant and the air to undergo forced convection heat exchange, thereby causing the high-temperature gaseous refrigerant to gradually release heat and condense into a medium-temperature and high-pressure liquid refrigerant; subsequently, the liquid refrigerant flows into the subcooler 3 for further cooling. In heating mode, the first heat exchanger 2 works as an evaporator. The low-temperature, low-pressure refrigerant liquid absorbs external heat in the fin heat exchanger 21 and evaporates into a gaseous state. The variable-frequency fan 22 ensures the heat exchange efficiency of the evaporator by adjusting the air volume. Throughout the process, the variable-frequency fan 22 can dynamically adjust the speed according to the system load or user needs to achieve precise air volume control. For example, when the ambient temperature is high or the system load is large, the variable-frequency fan 22 increases the speed to enhance the heat exchange effect; otherwise, it reduces the speed to reduce energy consumption. The setting of the variable-frequency fan 22 not only accelerates the condensation effect of the refrigerant, but also builds an intelligent adjustment mechanism for the first heat exchanger 2, allowing the first heat exchanger 2 to optimize its operation according to actual operating conditions, significantly improving the energy efficiency of the system.

[0035] 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 and high-pressure refrigerant liquid further cooled by the subcooler 3 enters the shell and tube heat exchanger, causing the refrigerant to flow in the shell and tube heat exchanger and perform heat exchange with the cooling water in the shell and tube heat exchanger. The refrigerant absorbs the heat of the cooling water and evaporates into a low-temperature and low-pressure gaseous refrigerant, providing cooling for the user. In heating mode, the high-temperature and high-pressure gaseous refrigerant enters the shell and tube heat exchanger, performs heat exchange with the water in the shell and tube heat exchanger, and the refrigerant condenses into a liquid. The shell and tube heat exchanger has a large heat exchange area and good heat transfer performance, which ensures efficient heat exchange and realizes 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 easy maintenance, which reduces the operating cost of the system.

[0036] Specifically, a first one-way valve 6a is provided between the second heat exchanger 4 and the subcooler 3, and 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 operates in the 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, the refrigerant is prevented from flowing in the opposite direction, ensuring that the refrigerant can flow along the predetermined path in the heating mode; in the process of 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, one-way flow of refrigerant is achieved in the heating mode, ensuring the normal operation of the system, avoiding backflow of refrigerant, reducing energy loss, and improving the energy efficiency of the system. Compared with the traditional heat recovery system that uses multiple four-way valves 9 and a heat exchanger with integrated condensing and subcooling functions, the application of the first one-way valve 6a simplifies the system structure and reduces costs.

[0037] Specifically, a heating expansion valve 7a is disposed between the first heat exchanger 2 and the subcooler 3. When the compression module 1 operates 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 for regulating the flow and pressure of the refrigerant. 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 is fully evaporated in the first heat exchanger 2. More specifically, in heating mode, the high-temperature, high-pressure gaseous refrigerant discharged from compression module 1 first enters second heat exchanger 4, where it condenses into a liquid state. The liquid refrigerant then flows through first one-way valve 6a to subcooler 3, where it is further cooled and the released heat is used to heat the water in water tank 5. When the supercooled liquid refrigerant reaches heating expansion valve 7a, the throttling action of heating expansion valve 7a causes the refrigerant's pressure and temperature to drop sharply, transforming it into a low-temperature, low-pressure gas-liquid mixture. After entering first heat exchanger 2, the low-temperature, low-pressure refrigerant absorbs heat from the external environment and evaporates into a gaseous refrigerant. Finally, the gaseous refrigerant returns to compression module 1, completing the heating cycle. The provision of heating expansion valve 7a enables precise control of the refrigerant flow and pressure during the heating process, ensuring efficient operation of the system in heating mode. By throttling and reducing the pressure of the refrigerant, the refrigerant can effectively absorb external heat in first heat exchanger 2, further improving the system's heating capacity.

[0038] 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 operating in cooling mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compression module 1 enters the first heat exchanger 2 for condensation. The condensed liquid refrigerant then flows through the second one-way valve 6b to the subcooler 3. Because the flow direction of the second one-way valve 6b is from the first heat exchanger 2 to the subcooler 3, the refrigerant can flow smoothly from the first heat exchanger 2 to the subcooler 3 in cooling mode, preventing reverse flow of the refrigerant. During the heat exchange process with the subcooler 3, the refrigerant is further cooled, and the heat released is used to heat the water in the water tank 5. The setting of the second one-way valve 6b ensures the one-way flow of the refrigerant in the refrigeration mode, optimizes the operating efficiency of the system, avoids the backflow of the refrigerant, reduces energy loss, and improves the energy efficiency of the system. Compared with the traditional heat recovery system that uses multiple four-way valves 9 and a heat exchanger with integrated condensing and subcooling functions, the application of the second one-way valve 6b simplifies the system structure and reduces costs.

[0039] Specifically, a refrigeration expansion valve 7b is provided between the second heat exchanger 4 and the subcooler 3. When the compressor is operating in cooling 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 for regulating the flow and pressure of the refrigerant. In this embodiment, the refrigeration expansion valve 7b throttles and reduces the pressure of the refrigerant in cooling mode, allowing the refrigerant to effectively absorb heat in the second heat exchanger 4 and ensuring that the refrigerant is fully evaporated 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. The released heat is used to heat the water in the water tank 5. When the supercooled refrigerant liquid reaches the refrigeration expansion valve 7b, the throttling effect of the refrigeration expansion valve 7b causes the refrigerant's pressure and temperature to drop sharply, transforming it into a low-temperature, low-pressure gas-liquid mixed state. After entering the second heat exchanger 4, the low-temperature, low-pressure refrigerant absorbs heat from the cooling water and evaporates into a gaseous refrigerant, thereby providing cooling capacity for the user. The provision of the refrigeration expansion valve 7b enables precise control of the refrigerant flow and pressure during the cooling process, ensuring efficient operation of the system in cooling mode. By throttling and reducing the pressure of the refrigerant, the refrigerant can effectively absorb external heat in the second heat exchanger 4, further improving the system's cooling capacity.

[0040] Specifically, the first one-way valve 6a is connected in parallel with the refrigeration expansion valve 7b. It can be understood that the flow direction of the first one-way valve 6a is opposite to that of the refrigeration expansion valve 7b. During the operation of the system, the parallel structure of the first one-way valve 6a and the refrigeration expansion valve 7b realizes the intelligent switching of the refrigerant flow direction in the cooling and heating modes. When the system is in the cooling mode, the high-temperature and high-pressure gaseous refrigerant discharged by the compression module 1 is condensed into liquid in the first heat exchanger 2, and then flows to the subcooler 3 through the second one-way valve 6b. The supercooled refrigerant liquid needs to be throttled and depressurized before entering the second heat exchanger 4 for evaporation. Since the flow direction of the first one-way valve 6a is opposite to the flow direction of the refrigerant, the first one-way valve 6a is in a closed state, and the refrigerant can only be throttled and depressurized through the refrigeration expansion valve 7b, and then enter the second heat exchanger 4. In heating mode, after the high-temperature, high-pressure gaseous refrigerant discharged from compression module 1 is condensed into a liquid in second heat exchanger 4, it is unable to pass through refrigeration expansion valve 7b due to the high resistance of refrigeration expansion valve 7b. Instead, the refrigerant flows through first check valve 6a to subcooler 3, and then enters first heat exchanger 2 after throttling and reducing the pressure through heating expansion valve 7a. The parallel design of first check valve 6a and 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 with integrated condensing and subcooling functions, this design reduces the number of four-way valves 9, reduces flow resistance, and thus reduces energy loss and improves the system's energy efficiency. Furthermore, this design simplifies system control, enabling active refrigerant flow in both cooling and heating modes without changing or adjusting the flow direction of first check valve 6a or refrigeration expansion valve 7b, thereby improving system operation convenience.

[0041] Specifically, the refrigeration expansion valve 7b is an electronic expansion valve. An electronic expansion valve uses an electronic signal to control its valve opening. In this embodiment, the electronic expansion valve, acting as the refrigeration expansion valve 7b, can adjust the refrigerant flow rate in real time based on system operating conditions. More specifically, the electronic expansion valve is equipped with a temperature sensor. The temperature sensor in the refrigeration expansion valve 7b senses the refrigerant temperature at the output of the first heat exchanger 2. The electronic expansion valve also automatically adjusts its valve opening, ensuring sufficient evaporation of the refrigerant in the first heat exchanger 2 and improving the system's heating efficiency. In cooling mode, when the compression module 1 is operating, the electronic expansion valve can adjust its valve opening in real time based on parameters such as the system load and the 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 its opening, allowing more refrigerant to enter the second heat exchanger 4 to meet cooling demand. When the system load decreases, the electronic expansion valve decreases its opening, reducing the refrigerant flow rate and avoiding unnecessary energy consumption. The precise control of the electronic expansion valve enables the refrigerant to fully evaporate in the second heat exchanger 4, thereby improving the cooling efficiency of the system and significantly improving the control accuracy and energy efficiency of the system. At the same time, the electronic expansion valve can also quickly respond to changes in the system operating conditions. When the system starts, stops or the load suddenly changes, the valve opening is quickly adjusted to ensure stable operation of the system.

[0042] Specifically, the second one-way valve 6b is connected in parallel with the heating expansion valve 7a. It can be understood that the flow direction of the second one-way valve 6b is opposite to that of the heating expansion valve 7a. During the operation of the system, the parallel structure of the second one-way valve 6b and the heating expansion valve 7a realizes the intelligent switching of the refrigerant flow direction in the heating and cooling modes. When the system is in the heating mode, the high-temperature and high-pressure gaseous refrigerant discharged by the compression module 1 is condensed into liquid in the second heat exchanger 4, and then flows to the subcooler 3 through the first one-way valve 6a; the supercooled refrigerant liquid needs to be throttled and depressurized before entering the first heat exchanger 2 for evaporation. Since the flow direction of the second one-way valve 6b is opposite to the flow direction of the refrigerant, the second one-way valve 6b is in a closed state, and the refrigerant can only be throttled and depressurized through the heating expansion valve 7a, and then enter the first heat exchanger 2. In cooling mode, the high-temperature, high-pressure gaseous refrigerant discharged from compression module 1 condenses into a liquid in first heat exchanger 2. Due to the high resistance of heating expansion valve 7a, the refrigerant cannot pass through heating expansion valve 7a. Instead, it flows through second one-way valve 6b to subcooler 3. After throttling and reducing the pressure by cooling expansion valve 7b, it enters second heat exchanger 4. This parallel structure ensures that the refrigerant flows along the predetermined path in different modes. The parallel design of second one-way valve 6b and heating expansion valve 7a enables switching of refrigerant flow between cooling and heating modes without the need for complex control logic, reducing redundant components in the system, lowering costs, and improving system reliability.

[0043] Specifically, the heating expansion valve 7a is an electronic expansion valve. An electronic expansion valve uses an electronic signal to control its valve opening. In this embodiment, the electronic expansion valve 7a serves as the heating expansion valve, enabling real-time adjustment of the refrigerant flow rate based on system operating conditions. More specifically, the electronic expansion valve 7a is equipped with a temperature sensor that senses the refrigerant temperature at the output of the first heat exchanger 2. The electronic expansion valve also automatically adjusts its valve opening, ensuring sufficient evaporation of the refrigerant in the first heat exchanger 2 and improving the system's heating efficiency. In heating mode, when the compression module 1 is operating, the electronic expansion valve adjusts its valve opening in real time based on parameters such as the system load and the 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 automatically increases its 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 decreases its opening, reducing the refrigerant flow rate and avoiding energy waste. The use of an electronic expansion valve as the heating expansion valve 7a allows the refrigerant to fully evaporate in the first heat exchanger 2, thereby improving the heating efficiency of the system. At the same time, the heating expansion valve 7a can also quickly respond to changes in the system operating conditions. When the system starts, stops, or the load suddenly changes, the valve opening is quickly adjusted to ensure stable operation of the system.

[0044] It is understood that in other embodiments, a thermal expansion valve can be used instead of an electronic expansion valve according to actual needs. The thermal expansion valve can control the valve opening through its own temperature sensing package and diaphragm to achieve throttling and pressure reduction control of the refrigerant.

[0045] Specifically, a first water pump 8a is provided between the water tank 5 and the subcooler 3. The two ends of the first water pump 8a are connected to the water inlet of the water tank 5 and the water outlet of the subcooler 3, respectively, and are used to drive hot water from the subcooler 3 into the water tank 5. When the refrigerant is supercooled in the subcooler 3, heat is released, which is absorbed by the water in the subcooler 3, causing the water temperature to rise. After the first water pump 8a is turned on, hot water flows out of the water outlet of the subcooler 3 and is then transported by the first water pump 8a to the water inlet of the water tank 5, where it is stored in the water tank 5 for users to access and 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 conditioning cooling and heating system to heat the user's water, thereby improving heat recovery efficiency and energy utilization, thus meeting the market demand for energy-saving and environmentally friendly air conditioning products.

[0046] Specifically, first water pump 8a is a variable frequency water pump. Through variable frequency control, first water pump 8a automatically adjusts the pump flow rate based on the water temperature in water tank 5, the system's heat recovery requirements, or user water needs. This helps improve energy utilization, avoids resource waste, and reduces system energy consumption. For example, when the water temperature in water tank 5 reaches a set value, first water pump 8a reduces its speed, reducing energy consumption.

[0047] Specifically, the water outlet of the water tank 5 is connected to the water inlet of the subcooler 3. This connection allows the water tank 5 to supply water to the subcooler 3, improving the subcooler 3's cooling efficiency for the refrigerant and shortening the heat exchange path between the refrigerant and water, thereby improving heat recovery efficiency. The water outlet of the subcooler 3 is connected to the water inlet of the water tank 5 via the first water pump 8a. Because the water outlet of the water tank 5 is connected to the water inlet of the subcooler 3, the water tank 5 and the 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 the water tank 5 flows out of the water outlet of the water tank 5 and is transported through a pipe to the water inlet of the subcooler 3. The refrigerant is supercooled in the 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, thereby increasing the water temperature. The heated hot water flows out of the water outlet of the subcooler 3 and is then transported back to the water inlet of the water tank 5 by the first water pump 8a, entering the water tank 5 for storage. This cycle continues, causing the water temperature in the water tank 5 to gradually increase. The hot water circulation loop realizes a closed loop of hot water, achieves effective heat recovery and utilization, and improves heat recovery efficiency. By directly transporting the low-temperature water in the water tank 5 to the subcooler 3, the heat released by the refrigerant is fully utilized, heat loss is reduced, and the water in the water tank 5 can be heated more quickly to meet the user's demand for hot water. In addition, the closed loop connection method makes the system structure more compact, reduces the floor space, and reduces installation costs.

[0048] Specifically, water tank 5 is also equipped with a water inlet, through which users access hot water from tank 5. When the user requires hot water, they simply open the inlet, and the hot water in tank 5 flows out under pressure. The provision of a water inlet directly meets the user's need for hot water, achieving an integrated design of the air conditioning system and hot water supply. This eliminates the need for additional hot water heating equipment, reduces system production and operating costs, and consequently, reduces user investment and operating expenses. The use of heat recovery technology to heat hot water improves energy utilization and reduces energy waste, meeting energy conservation and emission reduction requirements.

[0049] Specifically, a second water pump 8b is further provided at the water inlet of the second heat exchanger 4; the second water pump 8b is used to drive an external water source 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 operates 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 water inlet of the second heat exchanger 4 through a pipeline; in the second heat exchanger 4, the cold water exchanges heat with the low-temperature, low-pressure refrigerant. The refrigerant absorbs the heat of 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 of the water outlet 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 liquid in the second heat exchanger 4, releasing heat to the water flowing through the second heat exchanger 4.

[0050] Specifically, the second water pump 8b is a variable-frequency water pump. By providing 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, enabling flow regulation of the second water pump 8b and reducing energy consumption. Furthermore, the variable-frequency configuration of the first water pump 8a, the second water pump 8b, and the variable-frequency fan 22 enables intelligent regulation of the heat recovery system, further enhancing the user experience. Specifically, when the system operates in cooling mode, frequency control of the variable-frequency fan 22 and 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 of the system. When the system operates in heating mode, since both the condensation process and the subcooling process can provide heat to the user, the output of the variable-frequency fan 22 and the second water pump 8b can be controlled based on the priority of user needs.

[0051] More specifically, in cooling mode, the frequency of the variable-frequency fan 22 and the first water pump 8a can be adjusted based on the degree of subcooling. In practice, the system obtains the fin-liquid-tube temperature and condensing pressure of the first heat exchanger 2 and calculates the degree of subcooling. It also obtains the output temperature and condensing pressure of the subcooler 3 and calculates the heat recovery subcooling degree. This information is then used to control the frequency 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 degree of the first heat exchanger 2 is controlled at approximately 0°C; by adjusting the frequency of the first water pump 8a, the heat recovery subcooling degree of the subcooler 3 is controlled at 7-9°C.

[0052] 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 degree of subcooling. During specific implementation, the system obtains the shell-and-tube liquid-pipe temperature and condensing pressure of the second heat exchanger 4 to calculate the degree of subcooling of the shell-and-tube liquid-pipe, 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 degree of subcooling of the second heat exchanger 4 at around 0°C; the frequency of the first water pump 8a is adjusted to keep the degree of heat recovery subcooling of the subcooler 3 at 7-9°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, thereby 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 producing more hot water.

[0053] In a preferred embodiment, the second heat exchanger 4 can be connected to a water tank 5. The water tank 5 provides low-temperature water to the second heat exchanger 4. The low-temperature water exchanges heat with the refrigerant in the second heat exchanger 4, raising the water temperature and completing the heating of the water. The heated water is then stored in the water tank 5 for user access. The connection between the second heat exchanger 4 and the water tank 5 forms a closed-loop heat exchange circuit, preventing heat loss and significantly improving heat recovery efficiency. It also reduces reliance on external water sources and water supply systems, lowering system energy consumption and operating costs.

[0054] Specifically, compression module 1 includes a compressor 11 and a gas-liquid separator 12. The exhaust pipe of compressor 11 is connected to the second heat exchanger 4 and the first heat exchanger 2. One end of gas-liquid separator 12 is connected to the intake pipe of compressor 11, and the other end is connected to the second heat exchanger 4 and the first heat exchanger 2. Gas-liquid separator 12 is used to separate the gas and liquid of the refrigerant, ensuring that the refrigerant entering the compressor is in a gaseous state, preventing liquid refrigerant from entering compressor 11 and damaging the compressor due to liquid hammer, thereby ensuring the reliability and safety of the heat recovery system.

[0055] Specifically, the heat recovery system based on the subcooler of 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. Figure 4-5, the four ports are port C, port D, port E, and port S. Port C is connected to the end of the first heat exchanger 2 away 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 away from the subcooler 3, and port S is connected to the end of the gas-liquid separator 12 away from the compressor 11. When the compression module 1 operates in cooling mode, port D is connected to port C, and port E is connected to port S; when the compression module 1 operates in heating mode, port D is connected to port E, and port C is connected to port S. The setting of the four-way valve 9 enables the system to flexibly switch between cooling and heating modes, and also integrates the cooling and heating systems into one system, simplifying the system structure. Compared with the traditional independent dual-system design of cooling and heating, the application of the four-way valve 9 reduces the number of equipment, reduces the system volume, and improves the compactness and installation convenience of the system. When the system needs to operate in cooling mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 11 enters the four-way valve 9 from port D, then flows through port C to the first heat exchanger 2 for condensation. The condensed liquid refrigerant passes through the subcooler 3 and the refrigeration expansion valve 7b in sequence, then 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 the compressor 11. When the system needs to operate in heating mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 11 enters the four-way valve 9 from port D, then flows through port E to the second heat exchanger 4 for condensation. The condensed liquid refrigerant passes through the subcooler 3 and the heating expansion valve 7a in sequence, then 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 the compressor 11.

[0056] It can be understood that the compressor 11, the gas-liquid separator 12, the four-way valve 9, the first heat exchanger 2, the second one-way valve 6b, the heating expansion valve 7a, the subcooler 3, the first one-way valve 6b, the cooling expansion valve 7b, and the second heat exchanger 4 are connected through a refrigerant pipeline; the subcooler 3, the first water pump 8a, and the water tank 5 are connected through a water pipeline, and the second heat exchanger 4 is connected to an external water source through a water pipeline.

[0057] Example 2

[0058] See also Figure 1-5 An embodiment of the present invention provides an air-conditioning and hot water integrated machine, including the heat recovery system based on the supercooler of embodiment one.

[0059] The air-conditioning and hot water all-in-one machine of this embodiment is equipped with the heat recovery system based on the subcooler in Example 1, which integrates the cooling, heating and hot water supply functions into the same device, meets the diverse functional needs of users, avoids the duplication of construction and energy waste caused by the separation of the functions of traditional air-conditioning equipment and water heaters, greatly saves installation space and user investment costs, and has significant market competitiveness and application value; by utilizing the heat recovery system to efficiently utilize supercooled heat, waste heat can be simultaneously converted into hot water regardless of whether the air-conditioning is operating for cooling or heating, significantly improving energy utilization and reducing operating energy consumption; at the same time, the first water pump 8a, the second water pump 8b and the variable frequency fan 22 in the heat recovery system based on the subcooler can dynamically adjust the system operating parameters according to the ambient temperature or user needs to ensure that the equipment is always in an efficient operating state, which not only improves the cooling and heating efficiency, but also ensures a stable hot water supply, thereby improving the user experience.

[0060] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention 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 the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A heat recovery system based on a subcooler, characterized in that: include: 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 in sequence, the compression module is connected to the first heat exchanger and the second heat exchanger, and the compression module is used to compress the gaseous refrigerant; the water tank is connected to the subcooler, and the subcooler performs heat exchange with the refrigerant condensed by the first heat exchanger or the second heat exchanger to transfer heat to the water tank.

2. The heat recovery system based on a subcooler according to claim 1, characterized in that: A first one-way valve is provided between the second heat exchanger and the subcooler, and the flow direction of the first one-way 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 operates 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, the first heat exchanger in sequence, and then flows back to the compression module.

4. The heat recovery system based on a subcooler according to claim 1, characterized in that: 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.

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 operates 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, 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 further provided between the water tank and the supercooler; both ends of the first water pump are respectively connected to the water inlet end of the water tank and the water outlet end of the supercooler, for driving hot water from the supercooler into the water tank.

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

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 heat recovery system based on a subcooler according to claim 8, characterized in that: Also includes: Four-way valve; The four-way valve is provided with four ports, which are respectively connected to the exhaust pipe of the compressor, one end of the first heat exchanger away from the subcooler, one end of the second heat exchanger away from the subcooler, and one end of the gas-liquid separator away from the compressor.

10. An air-conditioning and hot water integrated machine, characterized in that: The heat recovery system comprises the subcooler-based heat recovery system according to any one of claims 1 to 9.

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