Heat pump system integrated with supercooling heat regenerator and control method

Abstract

The invention relates to the technical field of heat pump systems integrated with supercooling heat regenerators, in particular to a heat pump system integrated with a supercooling heat regenerator and a control method. The heat pump system integrated with the supercooling heat regenerator comprises a compressor, a four-way valve, a plate heat exchanger, the supercooling heat regenerator, a proportional three-way valve, an expansion valve and a fin heat exchanger. An exhaust port of the compressor, the four-way valve, the plate heat exchanger, the supercooling heat regenerator, the expansion valve and the fin heat exchanger are sequentially connected through pipelines to form a refrigerant circulation loop. A water channel, a first refrigerant channel and a second refrigerant channel are integrated in the supercooling heat regenerator, the proportional three-way valve communicates with the water channel, the first refrigerant channel is used for circulating liquid refrigerants, and the second refrigerant channel is used for circulating gaseous refrigerants. According to the heat pump system integrated with the supercooling heat regenerator, the supercooling degree of a refrigerant can be improved, energy consumption is reduced, the throttling stability of the expansion valve is guaranteed, and the service life of the heat pump system integrated with the supercooling heat regenerator is prolonged.

Description

Technical Field

[0001] This invention relates to the field of heat pump system technology with integrated subcooling regenerator, and more particularly to a heat pump system with integrated subcooling regenerator and its control method. Background Technology

[0002] With the increasing prominence of energy issues, heat pump equipment has been widely used in heating, cooling, and hot water supply due to its high efficiency and energy-saving characteristics. Among them, air source heat pump units, as a new type of heat pump, are attracting more and more attention due to their advantages such as low operating costs and convenient installation.

[0003] However, existing air source heat pumps still have some problems in actual operation. For example, when the ambient temperature rises or the unit load increases, the condensing pressure of the heat pump system tends to rise accordingly, causing the condenser to be unable to provide sufficient subcooling to the refrigerant liquid. On the one hand, insufficient subcooling directly reduces the refrigerant's unit heat exchange efficiency, resulting in a decrease in the unit's heating or cooling capacity, a significant reduction in the system's energy efficiency ratio, and difficulty in meeting the requirements for high-efficiency operation. On the other hand, insufficient subcooling can disrupt the stable throttling conditions of the expansion valve, causing throttling oscillations in the expansion valve, reducing the reliability of the heat pump system and affecting its service life.

[0004] Therefore, there is an urgent need to design a heat pump system and control method that integrates a subcooling regenerator to solve the above technical problems. Summary of the Invention

[0005] The purpose of this invention is to propose a heat pump system and control method with an integrated subcooling regenerator, which can improve the subcooling degree of the refrigerant in the heat pump system with the integrated subcooling regenerator, reduce energy consumption, ensure the stability of the expansion valve throttling, and extend service life.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] On one hand, the present invention provides a heat pump system with an integrated subcooling regenerator, including a compressor, a four-way valve, a plate heat exchanger, a subcooling regenerator, a proportional three-way valve, an expansion valve, and a finned heat exchanger. The discharge port of the compressor, the four-way valve, the plate heat exchanger, the subcooling regenerator, the expansion valve, and the finned heat exchanger are sequentially connected by pipelines to form a refrigerant circulation loop, and the finned heat exchanger is connected back to the four-way valve through pipelines, and the four-way valve is connected back to the suction port of the compressor.

[0008] The subcooling regenerator integrates a water channel, a first refrigerant channel, and a second refrigerant channel. The proportional three-way valve is connected to the water channel. The first refrigerant channel is used for the flow of liquid refrigerant, and the second refrigerant channel is used for the flow of gaseous refrigerant.

[0009] As an optional technical solution for a heat pump system with an integrated subcooling regenerator, one end of the first refrigerant channel is connected to the refrigerant outlet of the plate heat exchanger via a liquid pipe, and the other end of the first refrigerant channel is connected to the inlet of the expansion valve via a liquid pipe; one end of the second refrigerant channel is connected to the refrigerant outlet of the finned heat exchanger via a gas pipe, and the other end of the second refrigerant channel is connected to the four-way valve via a gas pipe.

[0010] As an optional technical solution for a heat pump system integrating a subcooling regenerator, the proportional three-way valve includes an inlet port, a first outlet port, and a second outlet port; the inlet port is connected to external cold water through an inlet pipe, the first outlet port is connected to the inlet of the water passage of the subcooling regenerator, and the outlet of the water passage is connected to the water inlet of the plate heat exchanger; the second outlet port is connected to the water inlet of the plate heat exchanger.

[0011] As an optional technical solution for a heat pump system with an integrated subcooling regenerator, the heat pump system with an integrated subcooling regenerator also includes a first liquid pipe temperature sensor, a second liquid pipe temperature sensor, a suction temperature sensor, and a coil temperature sensor.

[0012] The first liquid pipe temperature sensor is installed on the liquid pipe between the first refrigerant channel and the refrigerant outlet of the plate heat exchanger;

[0013] The second liquid pipe temperature sensor is installed on the liquid pipe between the first refrigerant passage and the expansion valve;

[0014] The suction temperature sensor is located between the suction port of the compressor and the four-way valve, and is used to detect the suction temperature of the compressor.

[0015] The coil temperature sensor is installed on the heat exchange coil of the finned heat exchanger and is used to detect the coil temperature.

[0016] As an optional technical solution for a heat pump system with an integrated subcooling regenerator, the heat pump system with an integrated subcooling regenerator further includes a first solenoid valve and a second solenoid valve. The first solenoid valve is connected in series on the gas pipe between the finned heat exchanger and the second refrigerant channel. One end of the second solenoid valve is connected to the inlet of the first solenoid valve, and the other end is connected to the four-way valve. The first solenoid valve and the second solenoid valve have opposite opening and closing states. The first solenoid valve and the second solenoid valve are used to regulate the flow path of the refrigerant flowing out of the finned heat exchanger.

[0017] On the other hand, the present invention provides a control method for a heat pump system with an integrated subcooling regenerator. This control method is used to control the aforementioned heat pump system with an integrated subcooling regenerator, and includes the following steps:

[0018] The condensation saturation temperature, the temperature of the liquid refrigerant flowing into the first refrigerant channel, and the temperature of the liquid refrigerant flowing out of the first refrigerant channel are obtained.

[0019] Calculate the primary subcooling degree of the subcooling effect of the associated plate heat exchanger;

[0020] When the subcooling is not less than the preset subcooling threshold, the proportional three-way valve is connected to the plate heat exchanger and disconnected from the subcooling regenerator.

[0021] When the primary subcooling is less than the preset subcooling threshold, the secondary subcooling is calculated based on the subcooling effect of the associated subcooling regenerator.

[0022] The water distribution ratio of the three-way valve is dynamically adjusted according to the secondary subcooling degree so that the liquid refrigerant is subcooled once by the plate heat exchanger and then subcooled twice by the cold regenerator.

[0023] As an optional technical solution for the control method of a heat pump system with an integrated subcooling regenerator, the steps of obtaining the condensation saturation temperature, the temperature of the liquid refrigerant flowing into the first refrigerant channel, and the temperature of the liquid refrigerant flowing out of the first refrigerant channel include:

[0024] The condensing pressure is detected by a high-pressure sensor installed on the compressor's exhaust pipe, and the corresponding condensing saturation temperature is determined by consulting a refrigerant saturation temperature lookup table based on the condensing pressure.

[0025] The temperature of the liquid refrigerant flowing into the first refrigerant channel is obtained by a first liquid pipe temperature sensor installed on the liquid pipe between the first refrigerant channel and the plate heat exchanger, and is recorded as the first liquid pipe temperature.

[0026] The temperature of the liquid refrigerant flowing out of the first refrigerant channel is obtained by a second liquid pipe temperature sensor installed on the liquid pipe between the first refrigerant channel and the expansion valve, and is recorded as the second liquid pipe temperature.

[0027] The step of calculating the primary subcooling degree of the associated plate heat exchanger subcooling effect includes: Primary subcooling degree = condensation saturation temperature – first liquid tube temperature;

[0028] The step of calculating the secondary subcooling degree of the associated subcooling regenerator subcooling effect includes: secondary subcooling degree = first liquid tube temperature - second liquid tube temperature.

[0029] As an optional technical solution for the control method of a heat pump system with an integrated subcooling regenerator, the step of dynamically adjusting the water distribution ratio of the proportional three-way valve according to the secondary subcooling degree includes:

[0030] The first outlet port of the proportional three-way valve is connected to the water passage of the subcooled regenerator, and the second outlet port of the proportional three-way valve is connected to the water inlet of the plate heat exchanger.

[0031] When the secondary subcooling is ≤5℃, the water volume allocated to the first outlet port by the proportional three-way valve is increased by 5% per cycle, and the water volume allocated to the second outlet port is decreased by 5% per cycle, with a 30-second adjustment cycle, until the secondary subcooling is >5℃ or the water volume at the first outlet port reaches the maximum limit.

[0032] When the secondary subcooling is greater than 15°C, the water volume allocated to the first outlet port by the proportional three-way valve is reduced by 5% per cycle, and the water volume allocated to the second outlet port is increased by 5% per cycle, with an adjustment cycle of 30 seconds, until the secondary subcooling is less than or equal to 15°C or the water volume at the second outlet port reaches the maximum limit.

[0033] As an optional technical solution for the control method of a heat pump system with an integrated subcooling regenerator, the control method of the heat pump system with an integrated subcooling regenerator further includes a suction gas regeneration control step:

[0034] Obtain the compressor's suction temperature and the coil temperature of the finned heat exchanger;

[0035] The suction superheat is calculated based on the suction temperature and the coil temperature, wherein the suction superheat = suction temperature - coil temperature;

[0036] The heat pump system with integrated subcooling regenerator is provided with a first solenoid valve connected in series between the finned heat exchanger and the second refrigerant channel, and a second solenoid valve connected in parallel across the two ends of the first solenoid valve, and the first solenoid valve and the second solenoid valve have opposite opening and closing states; the opening and closing states of the first solenoid valve and the second solenoid valve are adjusted according to the suction superheat to control whether the gaseous refrigerant flows through the second refrigerant channel to exchange heat with the liquid refrigerant.

[0037] As an optional technical solution for the control method of a heat pump system with an integrated subcooling regenerator, the step of obtaining the suction temperature of the compressor and the coil temperature of the finned heat exchanger includes detecting the suction temperature by means of a suction temperature sensor set between the compressor suction port and the four-way valve, and detecting the coil temperature by means of a coil temperature sensor set on the heat exchange coil of the finned heat exchanger.

[0038] The step of adjusting the on / off state of the first and second solenoid valves according to the intake superheat includes:

[0039] When the suction superheat is ≥5℃ and the current opening of the expansion valve is ≤400P, the first solenoid valve is closed and the second solenoid valve is opened, so that the gaseous refrigerant bypasses the second refrigerant channel and flows directly back to the suction port of the compressor through the four-way valve.

[0040] When the suction superheat is <1℃ and the current opening degree of the expansion valve is ≤60P, the first solenoid valve is opened and the second solenoid valve is closed, so that the gaseous refrigerant flows through the second refrigerant channel and exchanges heat with the liquid refrigerant in the first refrigerant channel.

[0041] The beneficial effects of the present invention include at least the following:

[0042] This invention provides a heat pump system with an integrated subcooling regenerator. The system includes a compressor, a four-way valve, a plate heat exchanger, a subcooling regenerator, a proportional three-way valve, an expansion valve, and a finned heat exchanger. The compressor's discharge port, the four-way valve, the plate heat exchanger, the subcooling regenerator, the expansion valve, and the finned heat exchanger are sequentially connected via pipelines to form a refrigerant circulation loop. The finned heat exchanger is connected back to the four-way valve via pipelines, and the four-way valve is connected back to the compressor's suction port. The subcooling regenerator internally integrates a water channel, a first refrigerant channel, and a second refrigerant channel. The proportional three-way valve is connected to the water channel. The first refrigerant channel is used for the flow of liquid refrigerant, and the second refrigerant channel is used for the flow of gaseous refrigerant.

[0043] The above optimization of refrigerant subcooling and heat exchange efficiency, achieved through the use of a subcooling regenerator and a proportional three-way valve, demonstrates how the three-fluid design of the subcooling regenerator—comprising a water channel, a first refrigerant channel, and a second refrigerant channel—ensures sufficient subcooling of the liquid refrigerant before it enters the expansion valve. This prevents efficiency losses due to insufficient refrigerant subcooling during expansion valve throttling, thereby improving the energy efficiency and extending the lifespan of the heat pump system with the integrated subcooling regenerator. Simultaneously, the proportional three-way valve, connected to the water channel, allows for adjustable water flow to accommodate different subcooling requirements, ensuring appropriate refrigerant subcooling. Furthermore, the subcooling regenerator improves the state of the high-pressure liquid refrigerant before throttling, preventing expansion valve oscillations caused by insufficient subcooling, ensuring stable compressor operation, and enhancing the stability and reliability of the heat pump system with the integrated subcooling regenerator.

[0044] The present invention also provides a control method for a heat pump system with an integrated subcooling regenerator. This control method can ensure that the refrigerant obtains sufficient subcooling, thereby improving the energy efficiency ratio and operational stability of the heat pump system with the integrated subcooling regenerator. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0046] Figure 1 This is a schematic diagram of a heat pump system with an integrated subcooling regenerator provided in an embodiment of the present invention;

[0047] Figure 2 This is a flowchart of a control method for a heat pump system with an integrated subcooling regenerator provided in an embodiment of the present invention.

[0048] Figure Labels

[0049] 1. Compressor; 2. Four-way valve; 3. Plate heat exchanger; 4. Subcooling regenerator; 41. Water passage; 42. First refrigerant passage; 43. Second refrigerant passage; 5. Proportional three-way valve; 6. Expansion valve; 7. Finned heat exchanger; 8. First liquid line temperature sensor; 9. Second liquid line temperature sensor; 10. Suction temperature sensor; 11. Coil temperature sensor; 12. First solenoid valve; 13. Second solenoid valve; 14. High pressure sensor. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0051] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0052] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0053] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0054] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0055] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0056] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0057] This embodiment provides a heat pump system with an integrated subcooling regenerator, which can improve the subcooling of the refrigerant in the heat pump system with the integrated subcooling regenerator, reduce energy consumption, ensure the stability of the expansion valve throttling, and extend service life.

[0058] like Figure 1As shown, the integrated subcooling regenerator heat pump system mainly includes a compressor 1, a four-way valve 2, a plate heat exchanger 3, a subcooling regenerator 4, a proportional three-way valve 5, an expansion valve 6, and a finned heat exchanger 7. The discharge port of the compressor 1, the four-way valve 2, the plate heat exchanger 3, the subcooling regenerator 4, the expansion valve 6, and the finned heat exchanger 7 are sequentially connected through pipelines to form a refrigerant circulation loop. The finned heat exchanger 7 is connected back to the four-way valve 2 through pipelines, and the four-way valve 2 is connected back to the suction port of the compressor 1. The subcooling regenerator 4 integrates a water channel 41, a first refrigerant channel 42, and a second refrigerant channel 43. The proportional three-way valve 5 is connected to the water channel 41. The first refrigerant channel 42 is used for the flow of liquid refrigerant, and the second refrigerant channel 43 is used for the flow of gaseous refrigerant. It can be understood that... Figure 1 The direction of refrigerant flow is indicated by a solid arrow. Figure 1 The direction of water flow is indicated by dashed arrows.

[0059] Based on the above design, in this embodiment, the subcooling and heat exchange efficiency of the refrigerant is optimized by setting up a subcooling regenerator 4 and a proportional three-way valve 5. The three-fluid design of the subcooling regenerator 4, namely the water channel 41, the first refrigerant channel 42, and the second refrigerant channel 43, ensures that the liquid refrigerant is sufficiently subcooled before entering the expansion valve 6. This avoids efficiency loss due to insufficient refrigerant subcooling when the expansion valve 6 is throttled, thereby improving the energy efficiency of the heat pump system with the integrated subcooling regenerator and extending its service life. At the same time, the proportional three-way valve 5 is connected to the water channel 41, which can adjust the water flow to adapt to different subcooling requirements and ensure that the refrigerant subcooling is appropriate. In addition, the subcooling regenerator 4 improves the state of the high-pressure liquid refrigerant before throttling, avoids oscillation of the expansion valve 6 due to insufficient subcooling, ensures the stable operation of the compressor 1, and improves the stability and reliability of the heat pump system with the integrated subcooling regenerator.

[0060] like Figure 1 As shown, in this embodiment, one end of the first refrigerant channel 42 is connected to the refrigerant outlet of the plate heat exchanger 3 through a liquid pipe, and the other end of the first refrigerant channel 42 is connected to the inlet of the expansion valve 6 through a liquid pipe; one end of the second refrigerant channel 43 is connected to the refrigerant outlet of the finned heat exchanger 7 through a gas pipe, and the other end of the second refrigerant channel 43 is connected to the four-way valve 2 through a gas pipe.

[0061] One end of the first refrigerant channel 42 is connected to the refrigerant outlet of the plate heat exchanger 3 via a liquid pipe, and the other end is connected to the inlet of the expansion valve 6 via a liquid pipe, ensuring that the liquid refrigerant, after condensing in the plate heat exchanger 3, can flow smoothly into the subcooling regenerator 4 for subcooling. One end of the second refrigerant channel 43 is connected to the refrigerant outlet of the finned heat exchanger 7 via a gas pipe, and the other end is connected to the four-way valve 2 via a gas pipe, allowing the gaseous refrigerant flowing out of the finned heat exchanger 7 to flow through the gas pipe into the second refrigerant channel 43 in the subcooling regenerator 4 to indirectly exchange heat with the liquid refrigerant in the first refrigerant channel 42, further improving the subcooling degree.

[0062] The water channel 41 of the subcooling regenerator 4 can introduce low-temperature chilled water (such as ambient chilled water or system return water) to directly exchange heat with the liquid refrigerant in the first refrigerant channel 42. Simultaneously, the low-temperature gaseous refrigerant (from the finned heat exchanger 7) in the second refrigerant channel 43 can indirectly exchange heat with the liquid refrigerant in the first refrigerant channel 42, further enhancing the subcooling of the refrigerant. Compared to traditional heat pump systems with integrated subcooling regenerators without a subcooling regenerator 4, this structure can improve the subcooling of the liquid refrigerant, reduce the amount of flash gas during throttling, thereby avoiding frequent fluctuations in the opening of the expansion valve 6 due to the unstable state of the refrigerant, improving the stability of the throttling of the expansion valve 6, and extending its service life.

[0063] like Figure 1 As shown, the proportional three-way valve 5 includes an inlet port (i.e., port A), a first outlet port (i.e., port B), and a second outlet port (i.e., port C). The inlet port is connected to external cold water through an inlet pipe. The first outlet port is connected to the inlet of the water passage 41 of the subcooling regenerator 4, and the outlet of the water passage 41 is connected to the water inlet of the plate heat exchanger 3, allowing cold water to flow through the subcooling regenerator 4 to provide the necessary cooling capacity for the refrigerant liquid. The second outlet port is connected to the water inlet of the plate heat exchanger 3. When the subcooling regenerator 4 is not required for subcooling, the cold water can flow directly to the plate heat exchanger 3 for normal heat exchange operations.

[0064] The proportional three-way valve 5's connection method enables flexible distribution of chilled water between the plate heat exchanger 3 and the subcooling regenerator 4, improving the utilization rate of chilled water and enhancing the adaptability of the heat pump system with integrated subcooling regenerator to different operating conditions.

[0065] Specifically, when the heat pump system with integrated subcooling regenerator needs to increase subcooling, the proportional three-way valve 5 can increase the opening of ports A and B and decrease the opening of port C, allowing more chilled water to enter the subcooling regenerator 4 to exchange heat with the liquid refrigerant. When the system has sufficient subcooling, the opening of ports A and C is increased, and the opening of port B is decreased, allowing chilled water to directly enter the plate heat exchanger 3, avoiding ineffective flow of chilled water in the subcooling regenerator 4. The second outlet port is directly connected to the water inlet of the plate heat exchanger 3, ensuring that the plate heat exchanger 3 always has sufficient chilled water regardless of whether the subcooling regenerator 4 needs water supply, preventing the condensing pressure of the plate heat exchanger 3 from increasing due to insufficient water volume, and further stabilizing the operation of the heat pump system with integrated subcooling regenerator.

[0066] like Figure 1 As shown, the heat pump system integrating the subcooling regenerator also includes a first liquid pipe temperature sensor 8, a second liquid pipe temperature sensor 9, a suction temperature sensor 10, and a coil temperature sensor 11. The first liquid pipe temperature sensor 8 is located on the liquid pipe between the first refrigerant passage 42 and the refrigerant outlet of the plate heat exchanger 3, and is used to monitor the temperature of the refrigerant liquid flowing into the subcooling regenerator 4 in real time. The second liquid pipe temperature sensor 9 is located on the liquid pipe between the first refrigerant passage 42 and the expansion valve 6, and is used to detect the temperature of the refrigerant liquid flowing out of the subcooling regenerator 4. The suction temperature sensor 10 is located between the suction port of the compressor 1 and the four-way valve 2, and is used to detect the suction temperature of the compressor 1. The coil temperature sensor 11 is located on the heat exchange coil of the finned heat exchanger 7, and is used to detect the coil temperature.

[0067] like Figure 1 As shown, the heat pump system with integrated subcooling regenerator also includes a first solenoid valve 12 and a second solenoid valve 13. The first solenoid valve 12 is connected in series on the gas pipe between the finned heat exchanger 7 and the second refrigerant channel 43. One end of the second solenoid valve 13 is connected to the inlet of the first solenoid valve 12, and the other end is connected to the four-way valve 2. The opening and closing states of the first solenoid valve 12 and the second solenoid valve 13 are opposite. The first solenoid valve 12 and the second solenoid valve 13 are used to regulate the flow path of the refrigerant flowing out of the finned heat exchanger 7.

[0068] The configuration of the first solenoid valve 12 and the second solenoid valve 13 enables flexible switching of the refrigerant flow path. Specifically, when the heat pump system with integrated subcooling and heat recovery needs to increase the superheat of the refrigerant, the first solenoid valve 12 opens and the second solenoid valve 13 closes. The gaseous refrigerant enters the second refrigerant channel 43 to exchange heat with the liquid refrigerant in the first refrigerant channel 42, thereby increasing the superheat of the refrigerant. When the superheat of the refrigerant is sufficient, the second solenoid valve 13 opens and the first solenoid valve 12 closes. The gaseous refrigerant flows directly back to the compressor 1, avoiding ineffective heat recovery that would increase the energy consumption of the heat pump system with integrated subcooling and heat recovery, thus saving costs.

[0069] like Figure 2As shown in the figure, this embodiment also provides a control method for a heat pump system with an integrated subcooling regenerator. The control method for the heat pump system with an integrated subcooling regenerator is used to control the aforementioned heat pump system with an integrated subcooling regenerator. The control method for the heat pump system with an integrated subcooling regenerator includes the following steps.

[0070] Step 1: Parameter Acquisition: Acquire the condensation saturation temperature of the refrigerant, the temperature of the liquid refrigerant flowing into the first refrigerant channel 42, and the temperature of the liquid refrigerant flowing out of the first refrigerant channel 42. Specifically, the controller of the heat pump system with integrated subcooling regenerator detects the condensing pressure through the high-pressure sensor 14 installed at the exhaust port of compressor 1, and acquires the temperatures of the liquid refrigerant flowing into and out of the first refrigerant channel 42 through the first liquid pipe temperature sensor 8 and the second liquid pipe temperature sensor 9, respectively.

[0071] Step 2: Calculate the primary subcooling degree of the subcooling effect of the associated plate heat exchanger 3.

[0072] Specifically, the controller has a built-in R32 refrigerant saturation temperature lookup table. Based on the detected condensing pressure, it looks up the corresponding refrigerant's condensing saturation temperature and then calculates the subcooling. The first subcooling = condensing saturation temperature - the temperature of the liquid refrigerant flowing into the first refrigerant channel 42, that is, the first subcooling = condensing saturation temperature - the temperature of the first liquid line.

[0073] Step 3: Control logic for proportional three-way valve 5.

[0074] When the subcooling is not less than the preset subcooling threshold (set to 5℃), the proportional three-way valve 5 is connected to the plate heat exchanger 3 and disconnected from the subcooling regenerator 4.

[0075] When the primary subcooling is less than the preset subcooling threshold, the secondary subcooling of the associated subcooling regenerator 4 is calculated; the water distribution ratio of the proportional three-way valve 5 is dynamically adjusted according to the secondary subcooling so that the liquid refrigerant is subcooled once by the plate heat exchanger 3 and then subcooled twice by the subcooling regenerator 4.

[0076] Specifically, when the primary subcooling is ≥5℃ (e.g., condensing saturation temperature 50℃, inflow temperature 45℃, primary subcooling 5℃), the controller outputs a signal to close the proportional three-way valve 5B port (connected to the subcooling regenerator 4) (0% opening), and fully open the C port (connected to the plate heat exchanger 3) and the A port (100% opening), so that cold water only enters the plate heat exchanger 3.

[0077] When the primary subcooling is less than 5℃ (e.g., condensation saturation temperature 50℃, inflow temperature 46℃, primary subcooling 4℃), the controller calculates the secondary subcooling = first liquid pipe temperature - second liquid pipe temperature. (e.g., inflow 46℃, outflow 42℃, secondary subcooling 4℃), and then adjusts the opening of ports B and C of the proportional three-way valve 5 according to the secondary subcooling.

[0078] The control method of this integrated subcooling regenerator heat pump system avoids the drawbacks of traditional integrated subcooling regenerator heat pump systems, which suffer from either no subcooling or complete subcooling, through a hierarchical logic of primary subcooling judgment and secondary subcooling adjustment. When the primary subcooling is sufficient, the water supply to the subcooling regenerator 4 is disconnected, thereby saving energy consumption of the integrated subcooling regenerator heat pump system. When the primary subcooling is insufficient, the secondary subcooling is precisely adjusted to increase the subcooling of the refrigerant, thereby improving the stability of the expansion valve 6 and reducing or avoiding throttling oscillation problems.

[0079] Further, in this embodiment, the steps of obtaining the condensation saturation temperature of the refrigerant, the temperature of the liquid refrigerant flowing into the first refrigerant channel 42, and the temperature of the liquid refrigerant flowing out of the first refrigerant channel 42 include:

[0080] Condensation saturation temperature acquisition: The condensing pressure is detected by the high-pressure sensor 14 installed on the discharge end pipeline of compressor 1. Based on the condensing pressure, the corresponding condensing saturation temperature is determined by consulting the refrigerant saturation temperature lookup table. For example, if the high-pressure sensor 14 detects a condensing pressure of 1.8 MPa at the discharge end of compressor 1, the controller consults the built-in R32 refrigerant saturation temperature lookup table (1.8 MPa corresponds to a saturation temperature of 50°C) and determines the condensing saturation temperature to be 50°C.

[0081] First liquid pipe temperature acquisition: The temperature of the liquid refrigerant flowing into the first refrigerant channel 42 is acquired by the first liquid pipe temperature sensor 8 installed on the liquid pipe between the first refrigerant channel 42 and the plate heat exchanger 3, and recorded as the first liquid pipe temperature. For example, the first liquid pipe temperature sensor 8 detects that the temperature of the liquid refrigerant flowing into the first refrigerant channel 42 is 46°C (recorded as the first liquid pipe temperature 46°C).

[0082] Second liquid pipe temperature acquisition: The temperature of the liquid refrigerant flowing out of the first refrigerant channel 42 is acquired by the second liquid pipe temperature sensor 9 installed on the liquid pipe between the first refrigerant channel 42 and the expansion valve 6, and recorded as the second liquid pipe temperature. For example, the second liquid pipe temperature sensor 9 detects that the temperature of the liquid refrigerant flowing out of the first refrigerant channel 42°C is 42°C (recorded as the second liquid pipe temperature 42°C).

[0083] Primary subcooling calculation: The steps for calculating the primary subcooling effect of the associated plate heat exchanger 3 include: Primary subcooling = Condensation saturation temperature – First liquid tube temperature. For example, the controller calculates the primary subcooling using the formula: 50℃ - 46℃ = 4℃ (< 5℃).

[0084] Secondary subcooling calculation: The steps for calculating the secondary subcooling effect of the associated subcooling regenerator 4 include: Secondary subcooling = First liquid tube temperature - Second liquid tube temperature. For example, the controller calculates the secondary subcooling using the formula: 46℃ - 42℃ = 4℃.

[0085] In this embodiment, the step of dynamically adjusting the water distribution ratio of the proportional three-way valve 5 according to the secondary subcooling degree includes:

[0086] The first outlet port of the proportional three-way valve 5 is connected to the water passage 41 of the subcooled regenerator 4, and the second outlet port of the proportional three-way valve 5 is connected to the water inlet of the plate heat exchanger 3.

[0087] When the secondary subcooling is ≤5℃, the water volume allocated to the first outlet port by the proportional three-way valve 5 is increased by 5% per cycle, and the water volume allocated to the second outlet port is decreased by 5% per cycle, with a 30-second adjustment cycle, until the secondary subcooling is >5℃ or the water volume at the first outlet port reaches the maximum limit.

[0088] When the secondary subcooling is greater than 15°C, the water volume allocated to the first outlet port by the proportional three-way valve 5 is reduced by 5% per cycle, and the water volume allocated to the second outlet port is increased by 5% per cycle, with a 30-second adjustment cycle, until the secondary subcooling is less than or equal to 15°C or the water volume at the second outlet port reaches the maximum limit.

[0089] In some optional embodiments, the initial state before adjustment is: primary subcooling 4°C < 5°C, secondary subcooling 4°C ≤ 5°C, and the current opening of the proportional three-way valve 5 is: port B 30% (water flow 1.5m³). 3 / h), C outlet 70% (water volume 3.5m 3 / h), total water volume 5m 3 / h.

[0090] Regulation logic execution: The controller operates in a 30-second regulation cycle. In each cycle, the output signal controls the proportional three-way valve 5B port opening to increase by 5% (to 35%), and the C port opening to decrease by 5% (to 65%), correspondingly increasing the water flow at port B to 1.75m³. 3 / h, the water flow at point C decreased to 3.25m 3 / h.

[0091] Post-adjustment monitoring: After the first cycle ends, check if the secondary subcooling rises to 4.5℃ (still ≤5℃), then continue the second cycle adjustment (B port 40%, C port 60%) until the secondary subcooling rises to 6℃ (>5℃), then stop the adjustment and maintain the current opening (B port 40%, C port 60%).

[0092] If the secondary subcooling is greater than 15°C, the opening of port B decreases by 5% and the opening of port C increases by 5% in each cycle, until the secondary subcooling is less than or equal to 15°C or the opening of port C reaches 100% (port B 0%).

[0093] A 30-second adjustment cycle and a 5% gradient are used to avoid fluctuations in subcooling caused by large one-time adjustments, ensuring a stable increase in subcooling, for example, an increase of 0.5–1°C per adjustment cycle. This results in a smoother response for the heat pump system with the integrated subcooling regenerator. This dynamic adjustment of the proportional three-way valve 5 can promptly adjust the water flow based on changes in secondary subcooling, ensuring the refrigerant liquid achieves suitable subcooling and further optimizing the operating performance of the heat pump system with the integrated subcooling regenerator.

[0094] The control method for the heat pump system with integrated subcooling regenerator in this embodiment also includes a suction gas regeneration control step:

[0095] Parameter acquisition: The suction temperature of compressor 1 and the coil temperature of finned heat exchanger 7 are acquired. Specifically, the suction temperature is detected by suction temperature sensor 10, which is located between the suction port of compressor 1 and four-way valve 2, and the coil temperature is detected by coil temperature sensor 11, which is located on the heat exchange coil of finned heat exchanger 7. For example, the suction temperature of compressor 1 is 15°C, and the coil temperature of finned heat exchanger 7 is 10°C.

[0096] Calculate the suction superheat: Based on the suction temperature and coil temperature, calculate the suction superheat as follows: Suction superheat = Suction temperature - Coil temperature. The suction superheat calculated using the formula is: 15℃ - 10℃ = 5℃.

[0097] Switching logic of the first solenoid valve 12 and the second solenoid valve 13: The heat pump system with integrated subcooling regenerator is provided with a first solenoid valve 12 connected in series between the finned heat exchanger 7 and the second refrigerant channel 43, and a second solenoid valve 13 connected in parallel across the two ends of the first solenoid valve 12, and the opening and closing states of the first solenoid valve 12 and the second solenoid valve 13 are opposite; the opening and closing states of the first solenoid valve 12 and the second solenoid valve 13 are adjusted according to the suction superheat to control whether the gaseous refrigerant flows through the second refrigerant channel 43 to exchange heat with the liquid refrigerant.

[0098] Specifically, when the suction superheat is ≥5°C and the current opening of expansion valve 6 is ≤400P, the first solenoid valve 12 is closed and the second solenoid valve 13 is opened, allowing the gaseous refrigerant to bypass the second refrigerant channel 43 and flow directly back to the suction port of compressor 1 via the four-way valve 2. For example, when the suction superheat is 5°C and the current opening of expansion valve 6 is 380P, the controller closes the first solenoid valve 12 and opens the second solenoid valve 13, allowing the gaseous refrigerant to bypass the second refrigerant channel 43 and flow directly back to the suction port of compressor 1 via the four-way valve 2.

[0099] When the suction superheat is <1℃ and the current opening degree of expansion valve 6 is ≤60P, the first solenoid valve 12 is opened and the second solenoid valve 13 is closed, so that the gaseous refrigerant flows through the second refrigerant channel 43 and exchanges heat with the liquid refrigerant in the first refrigerant channel 42. Through suction reheat control, the gaseous refrigerant can exchange heat with the liquid refrigerant when the suction superheat is low, thereby increasing the suction superheat, preventing liquid slugging in compressor 1, extending the service life of compressor 1, and improving the reliability of the heat pump system with integrated subcooling reheater.

[0100] This suction gas reheat control step also solves the problem of wasted energy due to ineffective reheat when the refrigerant suction superheat is sufficient. Specifically, when the calculated suction superheat is ≥5℃, the controller can reverse the flow by closing the first solenoid valve 12 and opening the second solenoid valve 13, allowing the gaseous refrigerant to bypass the reheat channel and flow directly back to the compressor 1. This avoids the gaseous refrigerant from heating up due to ineffective reheat and reduces pipeline resistance losses during the reheat process.

[0101] This suction reheat control step precisely regulates the flow path of the gaseous refrigerant and optimizes the suction superheat. When the suction superheat is low, the gaseous refrigerant is controlled to flow through the subcooler 4, exchanging heat with the liquid refrigerant to raise its temperature, preventing liquid slugging in compressor 1, and improving the operational reliability of the heat pump system with the integrated subcooler 4. When the suction superheat is high, it is controlled to bypass the subcooler 4, reducing refrigerant superheat, avoiding energy waste, and improving energy efficiency. This step achieves dynamic balance of suction superheat, enhancing the stability and adaptability of the heat pump system with the integrated subcooler 4, enabling it to operate efficiently and stably under different operating conditions.

[0102] Obviously, the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

[0103] Note that in the description of this specification, the references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

Claims

1. A heat pump system integrating a subcooling regenerator, characterized in that, The system includes a compressor (1), a four-way valve (2), a plate heat exchanger (3), a subcooling regenerator (4), a proportional three-way valve (5), an expansion valve (6), and a finned heat exchanger (7). The discharge port of the compressor (1), the four-way valve (2), the plate heat exchanger (3), the subcooling regenerator (4), the expansion valve (6), and the finned heat exchanger (7) are connected in sequence through pipelines to form a refrigerant circulation loop. The finned heat exchanger (7) is connected back to the four-way valve (2) through a pipeline, and the four-way valve (2) is connected back to the suction port of the compressor (1). The subcooled regenerator (4) integrates a water channel (41), a first refrigerant channel (42), and a second refrigerant channel (43). The proportional three-way valve (5) is connected to the water channel (41). The first refrigerant channel (42) is used for the flow of liquid refrigerant, and the second refrigerant channel (43) is used for the flow of gaseous refrigerant.

2. The heat pump system with an integrated subcooling regenerator according to claim 1, characterized in that, One end of the first refrigerant channel (42) is connected to the refrigerant outlet of the plate heat exchanger (3) through a liquid pipe, and the other end of the first refrigerant channel (42) is connected to the inlet of the expansion valve (6) through a liquid pipe; one end of the second refrigerant channel (43) is connected to the refrigerant outlet of the finned heat exchanger (7) through a gas pipe, and the other end of the second refrigerant channel (43) is connected to the four-way valve (2) through a gas pipe.

3. The heat pump system with an integrated subcooling regenerator according to claim 1, characterized in that, The proportional three-way valve (5) includes an inlet port, a first outlet port, and a second outlet port; the inlet port is connected to external cold water through an inlet pipe, the first outlet port is connected to the inlet of the water channel (41) of the subcooled regenerator (4), and the outlet of the water channel (41) is connected to the water inlet of the plate heat exchanger (3); the second outlet port is connected to the water inlet of the plate heat exchanger (3).

4. The heat pump system with an integrated subcooling regenerator according to claim 1, characterized in that, The heat pump system with integrated subcooling regenerator also includes a first liquid pipe temperature sensor (8), a second liquid pipe temperature sensor (9), a suction temperature sensor (10), and a coil temperature sensor (11). The first liquid pipe temperature sensor (8) is installed on the liquid pipe between the first refrigerant channel (42) and the refrigerant outlet of the plate heat exchanger (3); The second liquid pipe temperature sensor (9) is installed on the liquid pipe between the first refrigerant channel (42) and the expansion valve (6); The suction temperature sensor (10) is located between the suction port of the compressor (1) and the four-way valve (2) and is used to detect the suction temperature of the compressor (1); The coil temperature sensor (11) is installed on the heat exchange coil of the finned heat exchanger (7) to detect the coil temperature.

5. The heat pump system with an integrated subcooling regenerator according to claim 4, characterized in that, The heat pump system with integrated subcooling regenerator also includes a first solenoid valve (12) and a second solenoid valve (13). The first solenoid valve (12) is connected in series on the gas pipe between the finned heat exchanger (7) and the second refrigerant channel (43). One end of the second solenoid valve (13) is connected to the inlet of the first solenoid valve (12), and the other end is connected to the four-way valve (2). The opening and closing states of the first solenoid valve (12) and the second solenoid valve (13) are opposite. The first solenoid valve (12) and the second solenoid valve (13) are used to regulate the flow path of the refrigerant flowing out of the finned heat exchanger (7).

6. A control method for a heat pump system integrating a subcooling regenerator, characterized in that, The control method for the heat pump system with the integrated subcooling regenerator is used to control the heat pump system with the integrated subcooling regenerator as described in any one of claims 1-5, and the control method for the heat pump system with the integrated subcooling regenerator includes the following steps: The condensation saturation temperature of the refrigerant, the temperature of the liquid refrigerant flowing into the first refrigerant channel (42), and the temperature of the liquid refrigerant flowing out of the first refrigerant channel (42) are obtained. Calculate the primary subcooling degree of the subcooling effect of the associated plate heat exchanger (3); When the subcooling degree is not less than the preset subcooling threshold, the proportional three-way valve (5) is connected to the plate heat exchanger (3) and the proportional three-way valve (5) is disconnected from the subcooling regenerator (4). When the primary subcooling is less than the preset subcooling threshold, the secondary subcooling of the associated subcooling regenerator (4) is calculated. The water distribution ratio of the dynamic adjustment proportional three-way valve (5) for secondary subcooling is adjusted so that the liquid refrigerant is subcooled once by the plate heat exchanger (3) and then subcooled twice by the cold regenerator (4).

7. The control method for a heat pump system with an integrated subcooling regenerator according to claim 6, characterized in that, The steps of obtaining the condensation saturation temperature of the refrigerant, the temperature of the liquid refrigerant flowing into the first refrigerant channel (42), and the temperature of the liquid refrigerant flowing out of the first refrigerant channel (42) include: The condensing pressure is detected by a high-pressure sensor (14) installed on the exhaust pipe of the compressor (1), and the corresponding condensing saturation temperature of the refrigerant is determined by looking up the refrigerant saturation temperature reference table based on the condensing pressure. The temperature of the liquid refrigerant flowing into the first refrigerant channel (42) is obtained by the first liquid pipe temperature sensor (8) installed on the liquid pipe between the first refrigerant channel (42) and the plate heat exchanger (3), and is recorded as the first liquid pipe temperature. The temperature of the liquid refrigerant flowing out of the first refrigerant channel (42) is obtained by a second liquid pipe temperature sensor (9) installed on the liquid pipe between the first refrigerant channel (42) and the expansion valve (6), and is recorded as the second liquid pipe temperature. The steps for calculating the primary subcooling degree of the associated plate heat exchanger (3) include: primary subcooling degree = condensation saturation temperature – first liquid tube temperature; The step of calculating the secondary subcooling degree of the associated subcooling regenerator (4) includes: secondary subcooling degree = first liquid tube temperature - second liquid tube temperature.

8. The control method for a heat pump system with an integrated subcooling regenerator according to claim 7, characterized in that, The step of dynamically adjusting the water distribution ratio of the proportional three-way valve (5) according to the secondary subcooling degree includes: The first outlet port of the proportional three-way valve (5) is connected to the water passage (41) of the subcooled regenerator (4), and the second outlet port of the proportional three-way valve (5) is connected to the water inlet of the plate heat exchanger (3). When the secondary subcooling is ≤5℃, the water volume allocated to the first outlet port by the proportional three-way valve (5) is increased by 5% per cycle and the water volume allocated to the second outlet port is decreased by 5% per cycle, with a 30-second adjustment cycle, until the secondary subcooling is >5℃ or the water volume at the first outlet port reaches the maximum limit. When the secondary subcooling is greater than 15°C, the water volume allocated to the first outlet port by the proportional three-way valve (5) is reduced by 5% per cycle, and the water volume allocated to the second outlet port is increased by 5% per cycle, with a 30-second adjustment cycle, until the secondary subcooling is less than or equal to 15°C or the water volume at the second outlet port reaches the maximum limit.

9. The control method for a heat pump system with an integrated subcooling regenerator according to claim 6, characterized in that, The control method for the heat pump system with integrated subcooling regenerator also includes a suction gas regeneration control step: Obtain the suction temperature of the compressor (1) and the coil temperature of the finned heat exchanger (7); The suction superheat is calculated based on the suction temperature and the coil temperature, wherein the suction superheat = suction temperature - coil temperature; The heat pump system with integrated subcooling regenerator is provided with a first solenoid valve (12) connected in series between the finned heat exchanger (7) and the second refrigerant channel (43), and a second solenoid valve (13) connected in parallel across the first solenoid valve (12), and the first solenoid valve (12) and the second solenoid valve (13) have opposite switching states; the switching states of the first solenoid valve (12) and the second solenoid valve (13) are adjusted according to the suction superheat to control whether the gaseous refrigerant flows through the second refrigerant channel (43) to exchange heat with the liquid refrigerant.

10. The control method for a heat pump system with an integrated subcooling regenerator according to claim 9, characterized in that, The steps of obtaining the suction temperature of the compressor (1) and the coil temperature of the finned heat exchanger (7) include detecting the suction temperature by means of a suction temperature sensor (10) set between the suction port of the compressor (1) and the four-way valve (2), and detecting the coil temperature by means of a coil temperature sensor (11) set on the heat exchange coil of the finned heat exchanger (7). The step of adjusting the on / off state of the first solenoid valve (12) and the second solenoid valve (13) according to the intake superheat includes: When the suction superheat is ≥5℃ and the current opening degree of the expansion valve (6) is ≤400P, the first solenoid valve (12) is closed and the second solenoid valve (13) is opened, so that the gaseous refrigerant bypasses the second refrigerant channel (43) and flows back to the suction port of the compressor (1) directly through the four-way valve (2); When the suction superheat is <1℃ and the current opening degree of the expansion valve (6) is ≤60P, the first solenoid valve (12) is opened and the second solenoid valve (13) is closed, so that the gaseous refrigerant flows through the second refrigerant channel (43) and exchanges heat with the liquid refrigerant in the first refrigerant channel (42).

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