Three-pressure efficient air-cooled heat pump unit suitable for large temperature difference

Abstract

The utility model provides a three-pressure efficient air-cooled heat pump unit suitable for large temperature difference, which relates to the technical field of heat pump units, and comprises an evaporation pressure regulator, and the evaporation pressure regulator comprises a valve body, a valve core, a valve seat, a front diaphragm, a rear diaphragm and a linkage rod; the front diaphragm is communicated with the valve front pressure cavity; the rear diaphragm is communicated with the valve rear pressure cavity; the two ends of the linkage rod are mechanically connected with the front diaphragm and the rear diaphragm respectively, and a driving connector is formed in the middle of the linkage rod and connected with the valve element. The pressure change of the front pressure cavity of the valve is sensed through the front diaphragm, the pressure change of the rear pressure cavity of the valve is sensed through the rear diaphragm, the opening degree is synchronously adjusted by driving the valve element through rigid transmission of the linkage rod, the hysteresis of single pressure control is eliminated through double-diaphragm mechanical linkage, the suction pressure fluctuation of an auxiliary path compressor is reduced, and the service life of the auxiliary path compressor is prolonged. And the effect of reducing the hysteresis of the driving valve element is achieved.

Description

Technical Field

[0001] This utility model relates to the field of heat pump unit technology, and in particular to a three-pressure high-efficiency air-cooled heat pump unit suitable for large temperature differences. Background Technology

[0002] The three-pressure high-efficiency air-cooled heat pump unit suitable for large temperature differences is a heat pump system that achieves high-efficiency operation over a wide temperature range through multi-stage compression and pressure regulation technology. Its core lies in solving the problem of efficiency reduction in conventional heat pumps when cooling at high temperatures and heating at low temperatures by working together with the main circuit and the auxiliary circuit. It includes the main circuit compressor, the main circuit oil separator, the four-way reversing valve, the auxiliary circuit compressor, the auxiliary circuit oil separator, the evaporator pressure regulator, the heat exchange and throttling components, and the gas-liquid separation and control components.

[0003] A search revealed that utility model patent CN206944526U discloses a three-pressure high-efficiency air-cooled heat pump unit suitable for large temperature differences. It includes a main compressor, a main oil separator, a four-way reversing valve, an outdoor heat exchanger, an outdoor fan, a first one-way valve, a second one-way valve, a third one-way valve, a fourth one-way valve, a fifth one-way valve, a sixth one-way valve, a recooler, a dryer filter, an observation mirror, a first expansion valve, a medium-pressure gas-liquid separator, a second expansion valve, an indoor heat exchanger, a low-pressure gas-liquid separator, an evaporator pressure regulator, an auxiliary compressor, an auxiliary oil separator, and connecting pipes. This design addresses the prominent issues of high-temperature cooling operation in summer and low-temperature heating operation in winter. It also features a wide energy regulation range and rapid defrosting for energy saving, thus broadening the application areas of air-cooled heat pumps.

[0004] In the above-disclosed structure, the regulator relies solely on the inlet pressure, i.e., the evaporation pressure, for control. When operating conditions change abruptly, the response is delayed, which can easily cause fluctuations in the suction pressure of the auxiliary compressor. Utility Model Content

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a high-efficiency air-cooled heat pump unit with three pressures suitable for large temperature differences.

[0006] To achieve the above objectives, this utility model adopts the following technical solution: a high-efficiency air-cooled heat pump unit with three pressures and large temperature difference, comprising an evaporation pressure regulator, wherein the evaporation pressure regulator comprises a valve body, a valve core, a valve seat, a front diaphragm, a rear diaphragm, and a linkage rod; the front diaphragm is connected to the pressure chamber before the valve; the rear diaphragm is connected to the pressure chamber after the valve; the two ends of the linkage rod are mechanically connected to the front diaphragm and the rear diaphragm respectively, and a drive interface is provided in the middle of the linkage rod, wherein the drive interface is connected to the valve core.

[0007] Preferably, the linkage rod is a rigid lever structure, and a support member is provided on the surface of the linkage rod, the surface of which is fixed to the inner wall of the valve body.

[0008] Preferably, a balance spring is provided between the pressure chamber before the valve and the pressure chamber after the valve, and the balance spring is sleeved on the linkage rod.

[0009] Preferably, the sealing surfaces of the valve core and the valve seat are tapered, and the end of the valve core is connected to the linkage rod by a thread.

[0010] Preferably, the sensing chamber of the rear diaphragm is connected to a hydraulic damper, which consists of a piston and a chamber filled with oil.

[0011] Preferably, the front and rear diaphragms are made of 316L stainless steel with a thickness of 0.2-0.5 mm.

[0012] Preferably, the downstream pressure chamber of the evaporator pressure regulator is connected to the suction port of the auxiliary compressor via a metal pipeline.

[0013] Preferably, an elastic element, which is a wave spring, is provided between the linkage rod and the valve core.

[0014] Beneficial effects:

[0015] 1. This utility model realizes that by sensing the pressure change in the pressure chamber before the front diaphragm sensing valve and the pressure change in the pressure chamber after the rear diaphragm sensing valve, the valve core is driven to adjust the opening synchronously through the rigid transmission of the linkage rod. The mechanical linkage of the two diaphragms eliminates the lag of single pressure control, and the fluctuation of the auxiliary compressor suction pressure is reduced, thereby reducing the lag of the driven valve core.

[0016] 2. This utility model achieves the effect of reducing the risk of liquid slugging in the auxiliary circuit compressor by using a balance spring sleeved on the linkage rod, which compresses or releases kinetic energy to buffer the impact force when the pressure before or after the valve changes abruptly.

[0017] 3. This utility model achieves axial elastic compensation between the linkage rod and the valve core through the elastic element wave spring, which absorbs thermal expansion and contraction deformation, so that the equipment remains sealed at low temperatures, avoids ice blockage, and improves the applicability of the equipment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the present invention;

[0019] Figure 2 This is a schematic diagram illustrating the working principle of the evaporation pressure regulator of this utility model.

[0020] Figure 3 This is a flowchart illustrating the working process of the heat pump unit of this utility model;

[0021] Figure 4 This is a flowchart of the winter heating process of this utility model;

[0022] Figure 5 This is a flowchart illustrating the summer cooling process of this utility model.

[0023] Legend:

[0024] 1. Evaporator pressure regulator; 101. Valve body; 102. Valve core; 103. Valve seat;

[0025] 2. Front diaphragm; 201. Rear diaphragm; 202. Linkage rod;

[0026] 3. Pre-valve pressure chamber; 301. Post-valve pressure chamber;

[0027] 4. Support components;

[0028] 5. Balance spring;

[0029] 6. Hydraulic damper;

[0030] 7. Piston;

[0031] 8. Auxiliary compressor;

[0032] 9. Elastic elements. Detailed Implementation

[0033] To make the technical means, creative features, and achieved objectives and effects of this utility model easier to understand, the present utility model is further described below with reference to specific embodiments and accompanying drawings. However, the following embodiments are merely preferred embodiments of this utility model and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments described in the implementation plan without creative effort are all within the protection scope of this utility model.

[0034] The specific embodiments of this utility model are described below with reference to the accompanying drawings. Specific Implementation Example 1:

[0036] Reference Figures 1-5 This is suitable for high-efficiency air-cooled heat pump units with large temperature differences and three pressures. It includes an evaporator pressure regulator 1, which comprises a valve body 101, a valve core 102, a valve seat 103, a front diaphragm 2, a rear diaphragm 201, and a linkage rod 202. The front diaphragm 2 is connected to the pressure chamber 3 before the valve, and the rear diaphragm 201 is connected to the pressure chamber 301 after the valve. The two ends of the linkage rod 202 are mechanically connected to the front diaphragm 2 and the rear diaphragm 201, respectively. A drive interface is provided in the middle of the linkage rod 202, which is connected to the valve core 102. The front diaphragm 2 senses the pressure change in the pressure chamber 3 before the valve, and the rear diaphragm 201 senses the pressure change in the pressure chamber 301 after the valve. Through the rigid transmission of the linkage rod 202, the valve core 102 is driven to adjust the opening synchronously. The mechanical linkage of the two diaphragms eliminates the lag of single pressure control, and the suction pressure fluctuation of the auxiliary compressor 8 is reduced.

[0037] The linkage rod 202 is a rigid lever structure. A support member 4 is provided on the surface of the linkage rod 202. The surface of the support member 4 is fixed to the inner wall of the valve body 101. The support member 4 fixes the linkage rod 202 to the inner wall of the valve body 101, forming a lever fulcrum. The rigid structure of the linkage rod 202 ensures that the small displacement of the front diaphragm 2 or the rear diaphragm 201 is amplified into the effective stroke of the valve core 102. The lever amplification mechanism greatly improves the pressure response sensitivity and avoids the valve core 102 from jamming.

[0038] A balance spring 5 is provided between the pressure chamber 3 before the valve and the pressure chamber 301 after the valve. The balance spring 5 is sleeved on the linkage rod 202. When the pressure before or after the valve changes abruptly, the spring buffers the impact force by compressing or releasing elastic potential energy, and converts the elastic potential energy into internal energy through friction, thereby suppressing pressure oscillation and reducing the risk of liquid slugging in the auxiliary compressor 8.

[0039] The sealing surfaces of valve core 102 and valve seat 103 are tapered, and the end of valve core 102 is connected to linkage rod 202 by a thread. When the tapered sealing surface of valve core 102 fits against valve seat 103, leakage is greatly reduced. The threaded connection ensures the synchronous displacement of linkage rod 202 and valve core 102, thereby extending the sealing life and reducing refrigerant leakage.

[0040] The sensing chamber of the rear diaphragm 201 is connected to the hydraulic damper 6. The hydraulic damper 6 consists of a piston 7 and a chamber filled with oil. The hydraulic damper 6 filled with oil absorbs the instantaneous displacement of the rear diaphragm 201. The piston 7 converts the hydraulic pressure into a smooth mechanical motion, reducing the pressure surge during the defrosting mode switching.

[0041] The front diaphragm 2 and the rear diaphragm 201 are made of 316L stainless steel with a thickness of 0.2-0.5mm. The 0.2-0.5mm thick 316L stainless steel diaphragm is resistant to refrigerant corrosion and has a fatigue strength of 10 to the seventh power under commonly used operating conditions of -30℃ to 120℃, thereby improving the diaphragm life.

[0042] The downstream pressure chamber 301 of the evaporator pressure regulator 1 is connected to the suction port of the auxiliary compressor 8 through a metal pipe. The metal pipe directly transmits the actual pressure of the suction port of the auxiliary compressor 8 to the downstream diaphragm 201, reducing the pressure attenuation of the rubber hose and reducing pressure feedback error.

[0043] An elastic element 9 is provided between the linkage rod 202 and the valve core 102. The elastic element 9 is a wave spring. The wave spring provides axial elastic compensation between the linkage rod 202 and the valve core 102, absorbs thermal expansion and contraction deformation, and keeps the equipment sealed at a low temperature of -40℃ to avoid ice blockage. Specific Implementation Example 2:

[0045] Reference Figures 1-5The structure disclosed in this utility model was used by staff in a centralized heating renovation project in a frigid region of Inner Mongolia. The lowest winter temperature is -32 degrees Celsius, and the highest summer temperature is 42 degrees Celsius. The heat pump unit needs to raise the temperature of the air source (minus 15 degrees Celsius) to 55 degrees Celsius for water supply in winter (a temperature difference of 70 degrees Celsius), and lower the temperature of the return water (38 degrees Celsius) to 7 degrees Celsius in summer (a temperature difference of 31 degrees Celsius). During defrosting switching, the auxiliary compressor suction pressure of the original unit fluctuated by ±0.4 MPa, resulting in nine shutdowns per year.

[0046] In implementation, the valve body of the evaporative pressure regulator is made of QT450 ductile iron, and the valve core and seat sealing cone surfaces are overlaid with Stellite alloy. The front and rear diaphragms are made of 0.3 mm thick 316L stainless steel, and the linkage rod is a No. 45 steel forging (lever ratio 1:3). The balance spring stiffness is set at 80 N / mm and is fitted in the middle of the linkage rod. The hydraulic damper chamber is filled with No. 46 anti-wear hydraulic oil, and the piston stroke is 20 mm. The elastic element is a stainless steel wave spring (axial compensation ±0.5 mm). The downstream pressure chamber is directly connected to the suction port of the Bitzer SCC 065 auxiliary compressor via a copper pipe.

[0047] During operation in extremely cold winter conditions, when the ambient temperature suddenly drops to -28 degrees Celsius, the pressure chamber before the valve senses the evaporation pressure drop to 0.15 MPa, causing the front diaphragm to move the linkage rod to the left; simultaneously, the pressure chamber after the valve monitors the auxiliary compressor suction pressure dropping to 0.18 MPa, causing the rear diaphragm to move to the right. The dual diaphragms amplify the displacement through rigid levers, increasing the valve core opening by 40%, thus increasing the refrigerant flow rate to 320 kg / h. A 14mm compression balance spring absorbs pressure shocks, and a hydraulic damper delays the pressure jump during defrosting switching from 0.8 seconds to 2.5 seconds. A wave spring compensates for the 0.2mm metal contraction caused by temperatures of -30 degrees Celsius, ensuring a tight, leak-free seal.

[0048] During high-temperature operation in summer, at 42 degrees Celsius, the pressure before the valve surges to 1.8 MPa, causing the front diaphragm to push the linkage rod to move 30% to the right; simultaneously, the pressure after the valve rises to 1.5 MPa, causing the rear diaphragm to move in the opposite direction. This dual pressure feedback precisely reduces the valve opening by 25%, stabilizing the flow rate at 210 kg / h. The balance spring releases stored energy to suppress oscillations, and the wave spring absorbs 0.3 mm of thermal expansion.

[0049] Two consecutive heating seasons of operation showed that the auxiliary compressor suction pressure fluctuation was controlled within ±0.08 MPa, and the defrosting switching liquid slugging fault was eliminated. The unit achieved a heating efficiency ratio of 2.6 at -30°C and a cooling efficiency ratio of 3.9 at 42°C. The diaphragm fatigue life exceeded 5 million cycles, and the annual refrigerant leakage was less than 15 grams. Compared to before the upgrade, the system achieved an annual energy saving rate of 37.2%, and downtime due to malfunctions was reduced by 94%.

[0050] The working principle of this utility model is as follows: The unit achieves precise pressure control through the evaporator pressure regulator 1. The pressure change in the pressure chamber 3 before the valve acts on the front diaphragm 2, and the pressure change in the pressure chamber 301 after the valve acts on the rear diaphragm 201. The two are mechanically linked by the rigid linkage rod 202, which amplifies the displacement and drives the valve core 102 to synchronously adjust the opening, thereby dynamically balancing the suction pressure of the auxiliary compressor 8 and eliminating the lag of single pressure control. The balance spring 5 is sleeved on the linkage rod 202. When the pressure before or after the valve changes abruptly, it compresses or releases elastic potential energy to buffer pressure shocks and suppress oscillations. Low risk of liquid slugging; the hydraulic damper 6 connects to the sensing chamber of the diaphragm 201, and the oil-filled chamber and piston 7 convert instantaneous displacement into smooth motion, reducing pressure surges during defrosting switching; the elastic element 9 wave spring between the linkage rod 202 and the valve core 102 provides axial elastic compensation, absorbs thermal expansion and contraction deformation, and ensures that the sealing surface remains effectively in contact at -40℃, avoiding ice blockage; the conical sealing structure of the valve core 102 and the valve seat 103 combined with the threaded connection further reduces refrigerant leakage, ultimately achieving efficient and stable operation over a wide temperature range from -30℃ to 120℃.

[0051] 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.

[0052] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency air-cooled heat pump unit with three pressures suitable for large temperature differences, including an evaporator pressure regulator (1), characterized in that: The evaporation pressure regulator (1) includes a valve body (101), a valve core (102), a valve seat (103), a front diaphragm (2), a rear diaphragm (201), and a linkage rod (202); The front diaphragm (2) is connected to the pressure chamber (3) before the valve; The rear diaphragm (201) is connected to the pressure chamber (301) after the valve; The linkage rod (202) is mechanically connected to the front diaphragm (2) and the rear diaphragm (201) at both ends, and a drive interface is provided in the middle of the linkage rod (202), which is connected to the valve core (102).

2. The high-efficiency air-cooled heat pump unit with three pressures suitable for large temperature differences as described in claim 1, characterized in that: The linkage rod (202) is a rigid lever structure. The surface of the linkage rod (202) is provided with a support member (4), and the surface of the support member (4) is fixed to the inner wall of the valve body (101).

3. The high-efficiency air-cooled heat pump unit with three pressures suitable for large temperature differences as described in claims 1 and 2, characterized in that: A balance spring (5) is provided between the pressure chamber before the valve (3) and the pressure chamber after the valve (301), and the balance spring (5) is sleeved on the linkage rod (202).

4. The high-efficiency air-cooled heat pump unit with three pressures suitable for large temperature differences according to claim 3, characterized in that: The sealing surfaces of the valve core (102) and the valve seat (103) are tapered, and the end of the valve core (102) is connected to the linkage rod (202) by a thread.

5. The high-efficiency air-cooled heat pump unit with three pressures suitable for large temperature differences according to claim 1, characterized in that: The sensing chamber of the rear diaphragm (201) is connected to a hydraulic damper (6), which consists of a piston (7) and a chamber filled with oil.

6. The high-efficiency air-cooled heat pump unit with three pressures suitable for large temperature differences according to claim 1, characterized in that: The front diaphragm (2) and the rear diaphragm (201) are made of 316L stainless steel and have a thickness of 0.2-0.5mm.

7. The high-efficiency air-cooled heat pump unit with three pressures suitable for large temperature differences according to claim 1, characterized in that: The downstream pressure chamber (301) of the evaporator pressure regulator (1) is connected to the suction port of the auxiliary compressor (8) via a metal pipeline.

8. The high-efficiency air-cooled heat pump unit with three pressures suitable for large temperature differences according to claim 1, characterized in that: An elastic element (9) is provided between the linkage rod (202) and the valve core (102), and the elastic element (9) is a wave spring.

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