A swash plate compressor for a CO2 high temperature heat pump, a regulation system and a regulation method

Abstract

The application discloses a swash plate compressor, a regulating system and a regulating method for a CO2 high-temperature heat pump, which comprises an oil-gas cylinder, the upper portion of the oil-gas cylinder is connected with a box body, a plurality of CO2 cylinder assemblies are evenly arranged in the box body, and the CO2 cylinder assemblies are connected with the oil-gas cylinder; corresponding through holes are arranged on the oil-gas cylinder and the CO2 cylinder assemblies, piston assemblies are arranged in the through holes, and the piston assemblies and the through holes cooperatively form variable-volume chambers; the chambers are communicated with an oil pool through electromagnetic valve groups, the oil pool is communicated with high-pressure gas, the oil pool and the high-pressure gas cooperatively control the amount of hydraulic oil in the chambers through the electromagnetic valve groups, and the lower portion of the oil-gas cylinder is provided with a swash plate transmission structure matched with the piston assemblies. The application has the advantages of simple structure, adjustment of the amount of hydraulic oil in the chambers, change of the distance between the piston assemblies, change of the displacement and compression ratio of CO2 gas, reduction of operation energy consumption, and good realization of standardization, miniaturization and light weight.

Description

Technical Field

[0001] This invention relates to the field of compressor technology, and in particular to a novel swashplate compressor, regulating system and regulating method for CO2 high-temperature heat pumps. Background Technology

[0002] Carbon dioxide, as a natural and environmentally friendly refrigerant, is gradually gaining market favor due to its excellent low-temperature flow properties and heat exchange characteristics. With the increasing imminent replacement of traditional hydrocarbon-based refrigerants, using CO2 as the working fluid is an inevitable trend in the high-temperature heat pump industry. The safe and reliable operation of a carbon dioxide heat pump system is closely related to the selection of its basic materials and the sufficient pressure-bearing capacity of its components and instruments. According to reports, only by rationally selecting materials and pipe wall thickness can the reliability and safety of the system under a given pressure be guaranteed; ordinary components and materials cannot withstand the pressure requirements of carbon dioxide heat pumps. Because CO2 heat pumps operate at very high supercritical cycle pressures, exceeding 12 MPa, the large leakage and other drawbacks of traditional rotary compressors such as rotor and scroll compressors in refrigeration systems cannot be used. Reciprocating compressors are currently the only viable option for CO2 high-temperature heat pump systems. However, the connecting rod-crankshaft structure of reciprocating compressors results in a bulky and large compressor structure, as well as significant first- and second-order reciprocating inertial forces and moments, leading to considerable noise and vibration.

[0003] Swashplate compressors are an ideal solution for providing small-displacement, high-pressure gases, enabling miniaturization and weight reduction. However, their complex structure and high precision requirements limit their widespread adoption and application. Summary of the Invention

[0004] To address the shortcomings of the aforementioned background technology, this invention proposes a swashplate compressor, regulating system, and regulating method for CO2 high-temperature heat pumps, which solves the problems of large size, bulky and complex structure, and heavy weight of small CO2 high-temperature heat pump compressors in the prior art.

[0005] The technical solution of the present invention is implemented as follows: a swashplate compressor for a CO2 high-temperature heat pump includes an oil cylinder, a housing connected to the upper part of the oil cylinder, and a plurality of evenly distributed CO2 cylinder assemblies arranged inside the housing, all of which are connected to the oil cylinder; the oil cylinder and the CO2 cylinder assemblies are provided with corresponding through holes, and piston assemblies are provided in the through holes, and the piston assemblies cooperate with the through holes to form a chamber with variable volume; the lower part of the oil cylinder is provided with a swashplate transmission structure that cooperates with the piston assemblies.

[0006] Furthermore, the cylinder assembly includes a CO2 cylinder body, a gas cooler is provided on the upper part of the CO2 cylinder body, and a valve assembly is provided between the CO2 cylinder body and the gas cooler.

[0007] Furthermore, the oil-gas cylinder is provided with a plurality of uniformly distributed first cylinder holes, and the CO2 cylinder body is provided with a second cylinder hole that communicates with the first cylinder holes. The diameter of the first cylinder hole is larger than the diameter of the second cylinder hole, and the piston assembly is disposed in the through hole formed by the first cylinder hole and the second cylinder hole.

[0008] Furthermore, the piston assembly includes an oil piston and a gas piston. The oil piston is disposed in the first cylinder bore and is connected to the swashplate drive structure. The gas piston is disposed in the second cylinder bore. The distance between the oil piston disposed in the first cylinder bore and the gas piston disposed in the second cylinder bore is controlled by the amount of hydraulic oil in the chamber.

[0009] Furthermore, the swashplate drive structure includes a swashplate body, with a main shaft connected to the lower part of the swashplate body, and the inclined surface of the upper part of the swashplate body connected to the piston assembly via a connecting component.

[0010] Furthermore, the connecting assembly includes a swashplate, the lower part of which is connected to the swashplate body via a thrust bearing, and the upper part of which is hinged with several connecting rods that cooperate with the piston assembly.

[0011] Furthermore, the lower part of the oil cylinder is provided with an end cover, and the main shaft is connected to the end cover through an angular contact ball bearing, and the main shaft extends downward out of the end cover.

[0012] A regulating system for a swashplate compressor used in a CO2 high-temperature heat pump includes a chamber connected to an oil sump via a solenoid valve assembly. The oil sump is connected to a high-pressure gas, and the oil sump and high-pressure gas work together to control the hydraulic oil volume within the chamber via the solenoid valve assembly. The oil sump includes a high-pressure oil sump and a low-pressure oil sump, both of which are connected to the high-pressure gas. The hydraulic oil output terminal of the high-pressure oil sump and the hydraulic oil input terminal of the low-pressure oil sump are both connected to the chamber, and the hydraulic oil output terminal of the low-pressure oil sump is connected to the hydraulic oil input terminal of the high-pressure oil sump.

[0013] Furthermore, the high-pressure oil tank and the low-pressure oil tank are connected by a pipeline equipped with a solenoid valve N3. The high-pressure oil tank is connected to a high-pressure oil pipe equipped with a solenoid valve N1. The low-pressure oil tank is connected to a low-pressure oil pipe equipped with a solenoid valve N2. Both the high-pressure and low-pressure oil pipes are connected to their respective chambers via connecting pipes equipped with solenoid valves Y. Each of the high-pressure and low-pressure oil tanks is also connected to a high-pressure air pipe. The high-pressure air pipe connected to the high-pressure oil tank is equipped with a solenoid valve G01, and the high-pressure air pipe connected to the low-pressure oil tank is equipped with solenoid valves G02 and G03.

[0014] A method for regulating a swashplate compressor for a CO2 high-temperature heat pump includes a regulating system. Cold water is injected into the casing of the swashplate compressor. At this point, the water temperature is low, and solenoid valves G01, G02, N3, and N1 are closed. Solenoid valves Y and N2, corresponding to the inner chamber of the swashplate compressor, are opened. After some hydraulic oil is drained back to the low-pressure oil sump, all solenoid valves close. At this point, the compressor displacement increases, the clearance volume increases, and the pressure ratio decreases, rapidly heating the cold water into hot water. As the hot water temperature rises, the exhaust temperature of the CO2 gas to be compressed increases, increasing the compression ratio and decreasing the gas displacement. At this point, solenoid valves G02, N3, and N2 close, and solenoid valves G01, Y, and N1, corresponding to the chamber, open. Solenoid valve G01 opens, connecting the high-pressure oil sump to high-pressure gas. High-pressure gas is injected into the high-pressure oil sump, and after the hydraulic oil is compressed into the chamber, all solenoid valves close, completing the process of decreasing the compressor displacement, decreasing the clearance volume, and increasing the pressure ratio.

[0015] Furthermore, when the water volume in the tank is low or slow heating is required, the hydraulic oil in one or more chambers can be emptied to interrupt the gas compression in the CO2 cylinder corresponding to that chamber, thereby reducing the amount of hot water heated in the tank. When the pressure in the chamber exceeds the limit, the high-pressure protection is activated, and the solenoid valves Y and N2 corresponding to the chamber are both opened, allowing the hydraulic oil in the chamber to enter the low-pressure oil tank to complete the pressure relief. When the oil volume in the high-pressure oil tank is lower than that in the low-pressure oil tank, solenoid valves G02 and N3 are opened, and the remaining solenoid valves are closed. High-pressure gas is introduced into the low-pressure oil tank through solenoid valve G02, and hydraulic oil enters the high-pressure oil tank from the low-pressure oil tank through solenoid valve N2.

[0016] The beneficial effects of this invention are as follows: The invention has a simple structure. By adjusting the amount of hydraulic oil in the chamber, the distance between the piston assemblies is changed, thereby altering the CO2 gas displacement and compression ratio, which helps reduce operating energy consumption and achieves standardization, miniaturization, and weight reduction. By setting up a hydraulic cylinder and an oil piston, the clearance volume is changed by altering the amount of hydraulic oil in the cylinder, thus changing the CO2 flow rate and gas compression ratio. Since the diameter of the first cylinder bore of the hydraulic cylinder is larger than the diameter of the second cylinder bore of the CO2 cylinder body, the ratio of the gas piston's movement distance to the oil piston's movement distance is (the square of the hydraulic cylinder diameter and the CO2 cylinder body diameter), achieving a larger piston stroke with a smaller swing amplitude. The hydraulic cylinder, oil piston, and connecting rod are all of the same specifications, which is beneficial for mass production and manufacturing; the axial clearance can be adjusted using the amount of oil in the hydraulic cylinder, reducing machining accuracy and costs; the CO2 cylinder body can be manufactured with different cylinder diameters and heights according to different needs and can be interchanged, which is beneficial for standardized production. The CO2 cylinder block and gas cooler are installed in the condenser section, allowing for enhanced heat transfer and a compact compressor structure. High-pressure protection can be achieved through cylinder pressure and a solenoid valve. When the cylinder pressure exceeds the set pressure, the solenoid valve opens, allowing oil to flow back through it, thus reducing the cylinder pressure. Attached Figure Description

[0017] To more clearly illustrate the embodiments of the present invention, the accompanying drawings used in the description of the embodiments 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 these drawings without creative effort.

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

[0019] Figure 2 This is a system connection diagram of the present invention.

[0020] In the diagram: 1. Main spindle, 2. End cap, 3. Angular contact ball bearing, 4. Swashplate, 5. Thrust bearing, 6. Swing plate, 7. Connecting rod, 8. Hydraulic cylinder, 9. Hydraulic piston, 10. Chamber, 11. Cylinder body, 12. Gas piston, 13. Valve assembly, 14. Gas cooler, 15. Housing. Detailed Implementation

[0021] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figure 1As shown in Embodiment 1, a swashplate compressor for a CO2 high-temperature heat pump includes an oil cylinder 8. A housing 15 is connected to the upper part of the oil cylinder 8. The housing 15 can be filled with liquids such as water. A water inlet is located at the lower part of the housing 15 near the oil cylinder 8, and a water outlet is located at the upper part of the housing 15 away from the oil cylinder 8. Several evenly distributed CO2 cylinder assemblies are arranged inside the housing 15, and each CO2 cylinder assembly is connected to the oil cylinder 8. The CO2 cylinder assemblies are used to heat the water inside the housing 15. Corresponding through holes are provided on the oil cylinder 8 and the CO2 cylinder assemblies. Piston assemblies are installed within these through holes, and the piston assemblies cooperate with the through holes to form a variable-volume chamber 10. Changing the volume of the chamber 10 changes the distance between the piston assemblies, thereby changing the gas compression ratio within the CO2 cylinder assemblies. A swashplate drive structure that cooperates with the piston assemblies is located at the lower part of the oil cylinder 8. The swashplate drive structure is connected to the motor, which drives the piston assembly to move within the through-hole via the swashplate drive structure. This compresses the gas within the CO2 cylinder assembly and heats the water in the housing 15. This device effectively solves the problems of large size and heavy weight of small CO2 high-temperature heat pump compressors, which is conducive to standardized production. By adjusting the hydraulic oil volume in chamber 10, the distance between the piston assemblies can be changed, thereby altering the CO2 gas displacement and compression ratio, which helps reduce operating energy consumption.

[0023] Example 2: In a swashplate compressor for a CO2 high-temperature heat pump, the cylinder assembly includes a CO2 cylinder body 11. A gas cooler 14 is located on the upper part of the CO2 cylinder body 11, and a valve assembly 13 is located between the cylinder body 11 and the gas cooler 14. The valve assembly 13 includes an exhaust valve. The gas cooler 14 is a cast aluminum microchannel enhanced heat exchanger. The outer surface of the gas cooler 14 is cast with reinforced ribs to facilitate heat exchange with water. The CO2 cooling channels are machined into spiral microchannels to facilitate the transfer of heat from the CO2 gas to the gas cooler 14. The gas cooler 14 is connected to the CO2 cylinder body 11 and the valve plate on the exhaust valve by screws, all housed within the gas cooler 14. Cold water enters the gas cooler 14, absorbs heat from the gas cooler 14, is heated to a set temperature, and then flows out of the gas cooler 14.

[0024] All other structures are the same as in Example 1.

[0025] Example 3, a swashplate compressor for a CO2 high-temperature heat pump, differs from Example 2 in that the oil-gas cylinder 8 has several evenly distributed first cylinder holes, and the CO2 cylinder body 11 has a second cylinder hole communicating with the first cylinder holes. The diameter of the first cylinder hole is larger than the diameter of the second cylinder hole. Therefore, the ratio of the movement distance of the gas piston 12 to the movement distance of the oil piston 9 is the square of the diameter of the oil-gas cylinder 8 and the diameter of the CO2 cylinder body 11, achieving a larger piston stroke with a smaller oscillation amplitude. The CO2 cylinder body 11 can be manufactured with different cylinder diameters and heights according to different needs, and these cylinder bodies 11 can be interchanged, which is beneficial for standardized production. The piston assembly is disposed within the through hole formed by the first cylinder hole and the second cylinder hole.

[0026] In this embodiment, the piston assembly includes an oil piston 9 and a gas piston 12. The oil piston 9 is disposed in the first cylinder bore and is connected to the swashplate drive structure. The gas piston 12 is disposed in the second cylinder bore. The oil piston 9 pushes hydraulic oil to make the gas piston 12 move up and down within the cylinder body 11, thereby realizing the intake, compression, and exhaust of CO2 gas. The distance between the oil piston 9 disposed in the first cylinder bore and the gas piston 12 disposed in the second cylinder bore is controlled by the amount of hydraulic oil in the chamber 10. The axial clearance can be adjusted by utilizing the amount of hydraulic oil in the oil-gas cylinder 8, reducing machining accuracy and machining costs.

[0027] All other structures are the same as in Example 2.

[0028] like Figure 2 As shown in Embodiment 4, a swashplate compressor for a CO2 high-temperature heat pump differs from Embodiment 3 in that the swashplate drive structure includes a swashplate body 4. A main shaft 1 is connected to the lower part of the swashplate body 4, and the inclined surface of the upper part of the swashplate body 4 is connected to a connecting assembly, which is connected to a piston assembly. The main shaft 1 drives the swashplate body to rotate, and the inclined surface of the upper part of the swashplate body can drive the swing plate 6 to swing up and down. The swing plate 6 is connected to an oil piston 9 via a connecting rod 7, which moves up and down within the first oil hole of the oil cylinder 8. Multiple oil pistons 9 move up and down sequentially in a clockwise or counterclockwise direction, thereby driving hydraulic oil to move within the first and second cylinder holes. This achieves the purpose of the oil piston 9 driving the gas piston 12 to move up and down. Furthermore, a small movement of the oil piston 9 can drive the gas to move at a higher speed, achieving a larger piston stroke with a smaller swing amplitude.

[0029] In this embodiment, the connecting assembly includes a swing plate 6. The lower part of the swing plate 6 is connected to the swashplate body 4 via a thrust bearing 5. Several connecting rods 7 that cooperate with the piston assembly are hinged to the upper part of the swing plate 6. The connecting rods 7 are hinged to the lower part of the piston, and the connecting rods 7 and the piston assembly are in a one-to-one cooperation relationship. The swing plate 6 has guide rods, and the lower part of the oil cylinder 8 has a vertical guide groove. The guide rods slide up and down in the guide groove, restricting the swing plate 6 to only swing up and down. The guide rods and the vertical guide groove form an anti-rotation device to prevent the swing plate 6 from rotating. In the material selection of the connecting rods 7, oil pistons 9, and gas pistons 12, titanium alloy is selected for the connecting rods 7, cast aluminum for the oil pistons 9, and titanium alloy for the gas pistons 12, reducing the moving mass and achieving the purpose of reducing the first and second order reciprocating inertial forces of the compressor and reducing vibration. The oil cylinders 8 and 9, as well as the connecting rods 7, are all of the same specification, which is beneficial for mass production and manufacturing.

[0030] In this embodiment, the lower part of the hydraulic cylinder 8 is provided with an end cover 2. The main shaft 1 is connected to the end cover 2 through an angular contact ball bearing 3, and the main shaft 1 extends downward beyond the end cover 2. The main shaft 1 drives the swashplate to rotate. A thrust bearing 5 is provided between the swashplate and the swing plate 6. Since the swing plate 6 is restricted from rotating by the anti-rotation device, it swings axially under the push of the swashplate. Through the connection of the connecting rod 7, the oil piston 9 reciprocates in the hydraulic cylinder 8 as the swing plate 6 swings up and down, driving the hydraulic oil to move. Under the action of the hydraulic oil, the gas piston 12 reciprocates synchronously in the CO2 cylinder 11, realizing the intake, compression and exhaust of CO2 gas in the cylinder.

[0031] All other structures are the same as in Example 3.

[0032] Example 5: A regulating system for a swashplate compressor in a CO2 high-temperature heat pump includes a swashplate compressor. A chamber 10 is connected to an oil sump via a solenoid valve assembly. The oil sump is connected to a high-pressure gas source. The oil sump and high-pressure gas work together, and the solenoid valve assembly controls the hydraulic oil volume within the chamber 10. High-pressure protection can be achieved through the cylinder pressure and the solenoid valves. When the cylinder pressure exceeds a set pressure, the solenoid valves open, allowing hydraulic oil to flow back through them, thus reducing the cylinder pressure. The oil sump includes a high-pressure oil sump and a low-pressure oil sump, both connected to the high-pressure gas source. The hydraulic oil output of the high-pressure oil sump and the hydraulic oil input of the low-pressure oil sump are both connected to the chamber 10. The hydraulic oil output of the low-pressure oil sump is connected to the hydraulic oil input of the high-pressure oil sump. The high-pressure oil tank, the piston and the first cylinder bore of the oil-gas cylinder 8 and the second cylinder bore of the CO2 cylinder body 11 form a hydraulic oil circulation loop. The high-pressure oil tank and the low-pressure oil tank work together to adjust the amount of hydraulic oil in the chamber 10. The axial clearance can be adjusted by the amount of oil in the oil-gas cylinder 8, which reduces machining accuracy and machining cost. It achieves the purpose of changing the flow rate and compression ratio by changing the clearance volume, and achieving a larger piston stroke with a smaller swing amplitude.

[0033] In this embodiment, the high-pressure oil tank and the low-pressure oil tank are connected by a pipeline equipped with a solenoid valve N3. A high-pressure oil pipe is connected to the high-pressure oil tank, and a solenoid valve N1 is installed on the high-pressure oil pipe. A low-pressure oil pipe is connected to the low-pressure oil tank, and a solenoid valve N2 is installed on the low-pressure oil pipe. Both the high-pressure and low-pressure oil pipes are connected to their respective chambers via connecting pipes, and solenoid valves Y are installed on these connecting pipes. This device has n chambers 10, where n ≥ 2. The solenoid valves Y on the connecting pipes corresponding to each chamber 10 are Y01 to Yn, respectively. High-pressure air pipes are also connected to both the high-pressure and low-pressure oil tanks. A solenoid valve G01 is installed on the high-pressure air pipe connected to the high-pressure oil tank, and solenoid valves G02 and G03 are installed on the high-pressure air pipe connected to the low-pressure oil tank. High-pressure protection can be achieved through the cylinder pressure and the solenoid valves. When the cylinder pressure exceeds the set pressure, the solenoid valves open, oil flows back through the solenoid valves, and the cylinder pressure decreases.

[0034] All other structures are the same as in Example 4.

[0035] Example 6: A method for regulating a swashplate compressor for a CO2 high-temperature heat pump, comprising a regulating system. Cold water is injected into the housing 15 of the swashplate compressor. At this time, the water temperature is low, and solenoid valves G01, G02, N3, and N1 are closed. The swashplate compressor has n chambers. Solenoid valves Y01 to Yn and solenoid valve N2 corresponding to the n chambers 10 of the swashplate compressor are opened. After some hydraulic oil is discharged from the chamber 10 where the oil piston 9 is located back to the low-pressure oil sump, all solenoid valves are closed. At this time, the compressor displacement increases, the clearance volume increases, and the pressure ratio decreases, rapidly heating the cold water into hot water. The disc drive structure drives the piston to move, which can quickly heat cold water into hot water through the CO2 gas assembly. As the water temperature rises, the exhaust temperature of the compressed CO2 gas needs to rise, increasing the compression ratio and reducing the gas displacement. At this time, solenoid valves G02, N3, and N2 are closed, while solenoid valve G01, solenoid valve Y corresponding to chamber 10, and solenoid valve N1 are opened. Solenoid valve G01 opens to connect the high-pressure oil tank to the high-pressure gas. The high-pressure gas is injected into the high-pressure oil tank. After the hydraulic oil is pressed to the chamber 10 where the oil piston 9 is located, all solenoid valves are closed, thus reducing the compressor displacement, reducing the clearance volume, and increasing the pressure ratio.

[0036] In this embodiment, when the water volume in the tank 15 is low or slow heating is required, the hydraulic oil in one or more chambers 10 can be emptied to interrupt the gas compression in the CO2 cylinder 11 corresponding to that chamber, thereby reducing the amount of hot water heated in the tank 15. When the pressure in the chamber 10 exceeds the limit, the high-pressure protection is activated, and the solenoid valves Y and N2 corresponding to the chamber 10 are both opened, allowing the hydraulic oil in the chamber 10 to enter the low-pressure oil tank and complete the pressure relief. When the oil volume in the high-pressure oil tank is lower than that in the low-pressure oil tank, the solenoid valves G02 and N3 are opened, and the remaining solenoid valves are closed. The high-pressure gas is filled into the low-pressure oil tank through the solenoid valve G02, and the hydraulic oil enters the high-pressure oil tank from the low-pressure oil tank through the solenoid valve N2. This means that the flow rate and compression ratio are changed by altering the clearance volume, which is achieved through the switching of solenoid valves. Specifically, when heating at a low water temperature, the solenoid valve connected to the high-pressure oil tank is closed, and hydraulic oil is discharged into the low-pressure oil tank, accelerating the heating process. When the water temperature rises, the solenoid valve connected to the low-pressure oil tank is closed, and hydraulic oil enters the oil port from the high-pressure oil tank. For smaller water volumes, the number of solenoid valves on the oil cylinder 8 is changed to adjust the hydraulic oil volume in the oil port, achieving different heating speeds. High-pressure protection involves draining the hydraulic oil from the oil cylinder 8 back into the high-pressure oil cylinder.

[0037] All other structures are the same as in Example 5.

[0038] Example 7: A swashplate compressor, regulating system, and regulating method for a CO2 high-temperature heat pump, taking a swashplate compressor for a heat pump water heater with an outlet water temperature of 75°C as an example. Figure 1 and Figure 2As shown, an oil piston 9 is installed in the first cylinder bore of the oil-gas cylinder 8. A CO2 cylinder assembly is connected to the upper part of the oil-gas cylinder 8. The CO2 cylinder assembly has a second cylinder bore, the diameter of which is smaller than that of the first cylinder bore. A gas piston 12 is installed in the second cylinder bore. Hydraulic oil is filled between the oil piston 9 and the gas piston 12. A valve assembly 13 is installed on the upper part of the CO2 cylinder assembly. A gas cooler 14 is installed on the valve assembly 13, and a radiator is installed inside the gas cooler 14. The main shaft 1 drives the swashplate to rotate. A thrust bearing 5 is installed between the swashplate and the swing plate 6. Since the swing plate 6 cannot rotate due to the anti-rotation device, it swings axially under the push of the swashplate. Through the connection of the connecting rod 7, the oil piston 9 reciprocates in the oil-gas cylinder 8 as the swing plate 6 swings up and down, pushing the hydraulic oil to move. Under the action of the hydraulic oil, the gas piston 12 reciprocates synchronously in the CO2 cylinder body 11, realizing the intake, compression, and exhaust of CO2 gas in the cylinder.

[0039] This embodiment uses a five-cylinder assembly as an example. Five CO2 cylinder bodies are configured, each with a first cylinder bore diameter of Φ40mm. The centers of each cylinder are equidistantly distributed on the circumference of the oil-gas cylinder 8, which has a diameter of Φ178mm. The assembly is manufactured using integral casting of cast aluminum. This reduces the first and second-order reciprocating inertial forces of the compressor, while also minimizing airflow pulsation during intake and exhaust in each stage of the cylinder, thus reducing compressor noise and vibration.

[0040] The second cylinder bore inside the CO2 cylinder body 11 has a diameter of Φ20mm and is cast from HZ250 cast iron. The CO2 cylinder body 11 is connected to the oil cylinder 8 body by screws and is located on the upper side of the oil cylinder 8. The outer surface of the CO2 cylinder body 11 is cast with ribs, which facilitates heat dissipation and improves the efficiency of the compressor.

[0041] After being compressed within the CO2 cylinder block 11, the CO2 gas enters the gas cooler 14 through the exhaust valve. The gas cooler 14 is a cast aluminum microchannel enhanced heat exchanger. Reinforced fins are cast onto the outer surface of the gas cooler 14 to facilitate heat exchange with water. The CO2 cooling channels are machined into spiral microchannels to facilitate the transfer of heat from the CO2 gas to the gas cooler 14. The gas cooler 14 is connected to the CO2 cylinder block 11 and the valve plate with screws, all housed within the cooler. Cold water enters the cooler, absorbs heat from the five gas coolers 14, is heated to 75°C, and then flows out of the cooler.

[0042] The system adjustment method for the swashplate compressor used in the CO2 high-temperature heat pump is as follows: In this adjustment system, the solenoid valves corresponding to the five chambers 10 (i.e., n=5) formed by the five oil pistons 9 and the gas piston 12 are Y01, Y02, Y03, Y04, and Y05, respectively. When the CO2 heat pump water heater first starts heating cold water, the water temperature is low, requiring a large displacement of compressed CO2 gas with a low exhaust temperature to heat the water. At this time, solenoid valves G01, G02, N3, and N1 are closed, while Y01, Y02, Y03, Y04, Y05, and N2 are open. Some hydraulic oil is discharged back to the low-pressure oil sump on the right side. Then, all solenoid valves are closed. At this time, the compressor displacement increases, the clearance volume increases, and the pressure ratio decreases. As the water temperature rises, the exhaust temperature of the compressed CO2 gas needs to increase, increasing the compression ratio and decreasing the gas displacement. At this time, solenoid valves G02, N3, and N2 are closed, while solenoid valves G01, Y01, Y02, Y03, Y04, Y05, and N1 are open. Solenoid valve G01 is connected to high-pressure gas, which is injected into the high-pressure oil sump on the left side. The hydraulic oil is pressed to the oil piston 9, and then all solenoid valves close. At this time, the compressor displacement decreases, the clearance volume decreases, and the pressure ratio increases.

[0043] When the water consumption of a CO2 heat pump water heater is low, energy regulation is achieved by reducing the number of cylinders in operation. For example, when two cylinders need to work and three cylinders need to stop working, solenoid valves G01, G02, N3, N1, Y01, and Y03 are closed, while Y02, Y04, Y05, and N2 are open. The oil pistons 9 of cylinders 2, 4, and 5 discharge hydraulic oil to the low-pressure oil sump on the right side, and cannot transmit power to the gas piston 12. Therefore, the gas in the CO2 cylinder body 11 cannot be compressed.

[0044] When the compressed CO2 pressure inside the CO2 cylinder 11 exceeds the limit, high-pressure protection is triggered. At this time, solenoid valves G01, G02, N3, and N1 close, while solenoid valves Y01, Y02, Y03, Y04, Y05, and N2 open. The hydraulic oil is quickly discharged back to the low-pressure oil sump on the right side, and the CO2 gas inside the CO2 cylinder 11 is quickly depressurized, thus achieving high-pressure protection.

[0045] When the hydraulic oil level in the left high-pressure oil tank is low and the hydraulic oil level in the right low-pressure oil tank is high, solenoid valves G01, G03, Y01, Y02, Y03, Y04, Y05, N1, and N2 are closed, while G02 and N3 are opened. Solenoid valve G02 is connected to high-pressure gas, which is injected into the right low-pressure oil tank, and the hydraulic oil is forced to the left high-pressure oil tank.

[0046] All other structures are the same as in Example 6.

[0047] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for adjusting a swashplate compressor used in a CO2 high-temperature heat pump, characterized in that: The swashplate compressor includes an oil-gas cylinder (8), the upper part of which is connected to a housing (15). The housing (15) contains several evenly distributed CO2 cylinder assemblies, all of which are connected to the oil-gas cylinder (8). The oil-gas cylinder (8) and the CO2 cylinder assemblies have corresponding through holes, and piston assemblies are provided in the through holes. The piston assemblies cooperate with the through holes to form a variable volume chamber (10). The lower part of the oil-gas cylinder (8) is provided with a swashplate drive structure that cooperates with the piston assemblies. The cylinder assembly includes a CO2 cylinder body (11), a gas cooler (14) is provided on the upper part of the CO2 cylinder body (11), and a valve assembly (13) is provided between the CO2 cylinder body (11) and the gas cooler (14). The oil-gas cylinder (8) is provided with a number of evenly distributed first cylinder holes, and the CO2 cylinder body (11) is provided with a second cylinder hole that communicates with the first cylinder holes. The diameter of the first cylinder hole is larger than the diameter of the second cylinder hole, and the piston assembly is set in the through hole formed by the first cylinder hole and the second cylinder hole. The piston assembly includes an oil piston (9) and a gas piston (12). The oil piston (9) is disposed in the first cylinder bore and is connected to the swashplate drive structure. The gas piston (12) is disposed in the second cylinder bore. The distance between the oil piston (9) disposed in the first cylinder bore and the gas piston (12) disposed in the second cylinder bore is controlled by the amount of hydraulic oil in the chamber (10). The adjustment method includes an adjustment system, which includes a swashplate compressor. The chamber (10) inside the swashplate compressor is connected to the oil sump through a solenoid valve group. The oil sump is connected to the high-pressure gas. The oil sump and the high-pressure gas cooperate and control the hydraulic oil volume in the chamber (10) through the solenoid valve group. The oil sump includes a high-pressure oil sump and a low-pressure oil sump. Both the high-pressure oil sump and the low-pressure oil sump are connected to the high-pressure gas. The hydraulic oil output end of the high-pressure oil sump and the hydraulic oil input end of the low-pressure oil sump are connected to the chamber (10). The hydraulic oil output end of the low-pressure oil sump is connected to the hydraulic oil input end of the high-pressure oil sump. The high-pressure oil tank and the low-pressure oil tank are connected by a pipeline. The pipeline is equipped with a solenoid valve N3. The high-pressure oil tank is connected to a high-pressure oil pipe, which is equipped with a solenoid valve N1. The low-pressure oil tank is connected to a low-pressure oil pipe, which is equipped with a solenoid valve N2. The high-pressure oil pipe and the low-pressure oil pipe are connected to the corresponding chamber (10) through connecting pipes. The connecting pipes are equipped with a solenoid valve Y. The high-pressure oil tank and the low-pressure oil tank are also connected to high-pressure air pipes. The high-pressure air pipe connected to the high-pressure oil tank is equipped with a solenoid valve G01, and the high-pressure air pipe connected to the low-pressure oil tank is equipped with a solenoid valve G02 and a solenoid valve G03. Cold water is injected into the housing (15) of the swashplate compressor. At this time, the water temperature is low. Solenoid valves G01, G02, N3 and N1 are closed. Solenoid valves Y and N2 corresponding to the inner chamber (10) of the swashplate compressor are opened. After some hydraulic oil is discharged back to the low-pressure oil sump, all solenoid valves are closed. At this time, the compressor displacement increases, the clearance volume increases, the pressure ratio decreases, and the cold water is quickly heated into hot water. As the water temperature of the hot water rises, the exhaust temperature of the CO2 gas that needs to be compressed rises, the compression ratio increases, and the gas displacement decreases. When the solenoid valves G02, N3, and N2 close, the solenoid valves G01, Y, and N1 corresponding to the chamber (10) open. The opening of the solenoid valve G01 connects the high-pressure oil tank to the high-pressure gas. The high-pressure gas is injected into the high-pressure oil tank. After the hydraulic oil is pressed into the chamber (10), all the solenoid valves close, thus reducing the compressor displacement, decreasing the clearance volume, and increasing the pressure ratio. When the water volume in the tank (15) is low or slow heating is required, the hydraulic oil in one or more chambers (10) can be drained to interrupt the gas compression in the CO2 cylinder (11) corresponding to that chamber, thereby reducing the amount of heating water in the tank (15). When the pressure in chamber (10) exceeds the limit, the high pressure protection is activated, and the solenoid valves Y and N2 corresponding to chamber (10) are opened, and the hydraulic oil in chamber (10) enters the low pressure oil pool to complete the pressure relief. When the oil level in the high-pressure oil tank is lower than that in the low-pressure oil tank, solenoid valves G02 and N3 are opened, and all other solenoid valves are closed. High-pressure gas is introduced into the low-pressure oil tank through solenoid valve G02, and hydraulic oil enters the high-pressure oil tank from the low-pressure oil tank through solenoid valve N2.

2. The adjustment method for the swashplate compressor of a CO2 high-temperature heat pump according to claim 1, characterized in that: The swashplate drive structure includes a swashplate body (4), the lower part of which is connected to a main shaft (1), and the inclined surface of the upper part of the swashplate body (4) is connected to a piston assembly through a connecting assembly.

3. The adjustment method for the swashplate compressor of a CO2 high-temperature heat pump according to claim 2, characterized in that: The connecting assembly includes a swashplate (6), the lower part of which is connected to the swashplate body (4) via a thrust bearing (5), and the upper part of which is hinged with several connecting rods (7) that cooperate with the piston assembly.

4. The adjustment method for the swashplate compressor of a CO2 high-temperature heat pump according to claim 3, characterized in that: The lower part of the oil cylinder (8) is provided with an end cover (2), the main shaft (1) is connected to the end cover (2) through an angular contact ball bearing (3), and the main shaft (1) extends downward out of the end cover (2).

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