Energy-saving carbon dioxide heat pump

Abstract

The present application relates to the technical field of heat pump, disclose a kind of energy-saving carbon dioxide heat pump, wherein carbon dioxide scroll compressor includes fixed scroll, orbiting scroll, rack and back pressure cavity, orbiting scroll bottom plate is equipped with back pressure hole, throttle component is installed in back pressure hole. Throttle component includes throttle hole seat, main throttle hole, auxiliary throttle hole and elastic valve sheet, elastic valve sheet covers on the top of auxiliary throttle hole outlet, and the opening of auxiliary throttle hole is automatically adjusted according to the pressure difference between compression cavity and back pressure cavity. Orbiting scroll bottom plate back is equipped with annular pressure equalizing groove and radiation distribution groove, annular pressure equalizing groove is communicated to the outlet of each throttle component along the circumferential direction to realize circumferential pressure equalization, and radiation distribution groove distributes the gas to the inner and outer edge regions of back pressure cavity after pressure equalization. The present application is through the synergistic effect of self-adapting throttle and pressure equalizing groove network, so that back pressure cavity can quickly respond to pressure change and realize uniform distribution under the variable frequency condition of compressor, improve the precision and stability of orbiting scroll axial gap control.

Description

Technical Field

[0001] This invention relates to the field of heat pump technology, and more specifically, to an energy-saving carbon dioxide heat pump. Background Technology

[0002] A carbon dioxide heat pump is an energy-saving device that uses carbon dioxide as the working fluid and utilizes the reverse Carnot cycle principle to transfer heat. Carbon dioxide, as a natural working fluid, has excellent heat release characteristics in transcritical cycles, making it suitable for applications requiring large temperature rises, such as heat pump water heaters. The carbon dioxide scroll compressor is the core component of a carbon dioxide heat pump system; its moving scroll and stationary scroll need to maintain a small axial clearance to balance sealing and movement flexibility.

[0003] In the prior art, carbon dioxide scroll compressors typically employ a back pressure chamber structure to apply axial thrust to the moving scroll. The back pressure chamber is connected to the intermediate pressure stage of the compression chamber through a back pressure hole. The intermediate pressure is used to push the moving scroll closer to the fixed scroll, thereby achieving adaptive adjustment of the axial clearance.

[0004] However, when the compressor operates under variable frequency conditions, the pressure build-up rate and distribution characteristics within the compression chamber change significantly. The back pressure chamber, due to its relatively large volume and the delayed throttling response of the back pressure orifice, cannot keep up with the changing operating conditions. Simultaneously, gas entering the back pressure chamber from the back pressure orifice needs to diffuse throughout the chamber to establish uniform pressure, leading to uneven stress on the moving scroll and causing it to tilt. This combined effect of pressure response mismatch and uneven distribution causes axial displacement fluctuations and tilting oscillations in the moving scroll during frequency switching, resulting in increased scroll scraping or leakage, reduced compressor efficiency, and impacting the overall energy-saving performance of the carbon dioxide heat pump system. Summary of the Invention

[0005] This invention provides an energy-saving carbon dioxide heat pump that solves the technical problem in related technologies where the pressure response of the back pressure chamber of a carbon dioxide scroll compressor is lagging and unevenly distributed under variable frequency operation, leading to unstable control of the axial clearance of the moving scroll.

[0006] This invention discloses an energy-saving carbon dioxide heat pump, comprising a heat pump circulation system and a carbon dioxide scroll compressor. The heat pump circulation system includes a carbon dioxide scroll compressor, a gas cooler, a throttling device, and an evaporator, which are sequentially connected by pipelines to form a closed transcritical carbon dioxide circulation loop. The carbon dioxide scroll compressor includes a fixed scroll, a moving scroll, a frame, and a back pressure chamber. A back pressure hole is provided on the bottom plate of the moving scroll, and a throttling component is installed in the back pressure hole. The throttling component includes a throttling orifice seat, a main throttling orifice, an auxiliary throttling orifice, an elastic valve plate, and a limiting member. The elastic valve plate covers the outlet of the auxiliary throttling orifice. An annular pressure equalization groove and a radial distribution groove are provided on the back side of the bottom plate of the moving scroll. The annular pressure equalization groove connects the outlets of each throttling component circumferentially, and the radial distribution groove connects the annular pressure equalization groove with the inner and outer edge regions of the back pressure chamber.

[0007] Furthermore, the elastic valve plate is a stainless steel spring plate with a thickness of 0.1 to 0.3 mm. When there is a preset pressure difference between the compression chamber and the back pressure chamber, it can generate elastic deformation to open the auxiliary throttling orifice.

[0008] Furthermore, the limiting component is an arc-shaped baffle fixed to the end face of the throttle orifice seat, and the gap between the arc surface of the arc-shaped baffle and the upper surface of the free end of the elastic valve plate is 0.3 to 0.8 mm.

[0009] Furthermore, there are three throttling components, which are evenly distributed at 120 degrees along the circumference of the bottom plate of the moving vortex disk.

[0010] Furthermore, the number of radiation distribution slots is six to twelve, and the circumferential angle between adjacent radiation distribution slots is equal.

[0011] Furthermore, a sealing ring is provided between the outer circular surface of the throttling orifice seat and the wall of the back pressure hole, and the sealing ring is embedded in the annular groove of the outer circular surface of the throttling orifice seat.

[0012] Furthermore, the width of the annular equalizing groove is two to five millimeters, and the radial position of the annular equalizing groove ensures that the outlets of each throttling component fall within the width range of the annular equalizing groove.

[0013] Furthermore, the radiation distribution groove is also provided with a bifurcated branch groove in the radially outer region, which branches off from the middle section of the radiation distribution groove and extends to both sides in the circumferential direction.

[0014] The energy-saving carbon dioxide heat pump provided by this invention utilizes a throttling assembly with a main throttling orifice, an auxiliary throttling orifice, and an elastic valve plate at the back pressure hole position on the bottom plate of the moving scroll. The elastic valve plate automatically adjusts the opening of the auxiliary throttling orifice according to the pressure difference between the compression chamber and the back pressure chamber, achieving an adaptive throttling function of rapid gas filling during acceleration and moderate gas release during deceleration. Furthermore, by setting an annular pressure equalization groove and a radial distribution groove on the back side of the bottom plate of the moving scroll to form a pressure equalization groove network, circumferential pressure equalization and radial distribution of the gas in the back pressure chamber are achieved. This invention solves the technical problems of lag and uneven pressure distribution in the back pressure chamber of carbon dioxide scroll compressors under variable frequency operation, achieving the technical effects of improving the control accuracy and stability of the axial clearance of the moving scroll, reducing axial leakage loss and frictional power consumption, and improving compressor efficiency. Attached Figure Description

[0015] Figure 1 A schematic diagram of the structure of an energy-saving carbon dioxide heat pump Figure 1 ; Figure 2 A schematic diagram of the structure of an energy-saving carbon dioxide heat pump Figure 2 ; Figure 3 A schematic diagram of the structure of an energy-saving carbon dioxide heat pump Figure 3; Figure 4 Schematic diagram of the moving scroll plate Figure 1 ; Figure 5 Schematic diagram of the moving scroll plate Figure 2 ; Figure 6 This is a cross-sectional view of an energy-saving carbon dioxide heat pump; Detailed Implementation

[0016] A carbon dioxide heat pump is an energy-saving device that uses carbon dioxide as the working fluid to transfer heat, based on the reverse Carnot cycle principle. Carbon dioxide, as a natural working fluid, exhibits excellent heat release characteristics in transcritical cycles, making it suitable for applications requiring large temperature rises, such as heat pump water heaters. However, the high-pressure side pressure of a carbon dioxide heat pump system can reach eight to twelve MPa, placing higher demands on the compressor's sealing and efficiency.

[0017] The carbon dioxide scroll compressor 1 is the core component of the carbon dioxide heat pump system. Its moving scroll 3 and fixed scroll need to maintain a small axial clearance. Excessive axial clearance between the moving scroll 3 and fixed scroll will increase axial leakage, while insufficient clearance will cause dry friction. Existing technology uses a back pressure chamber structure to apply axial thrust to the moving scroll 3. The back pressure chamber is connected to the intermediate pressure stage of the compression chamber through a back pressure hole 4. This intermediate pressure pushes the moving scroll 3 closer to the fixed scroll, achieving adaptive adjustment of the axial clearance.

[0018] When the compressor operates under variable frequency conditions, the pressure build-up rate and distribution characteristics within the compression chamber change significantly. However, due to its relatively large volume and the delayed throttling response of the back pressure chamber (back pressure orifice 4), the pressure in the back pressure chamber cannot keep pace with these changes. Simultaneously, after entering the back pressure chamber through the back pressure orifice 4, the gas needs to diffuse throughout the chamber to establish uniform pressure. The pressure response is faster near the back pressure orifice 4 and slower further away, causing uneven stress on the moving scroll 3 and resulting in tilting. This mismatch in pressure response and uneven distribution, combined, causes axial displacement fluctuations and tilting oscillations in the moving scroll 3 during frequency switching, leading to increased scroll scraping or leakage, reduced compressor efficiency, and impacting the overall energy-saving performance of the carbon dioxide heat pump system.

[0019] like Figure 1-6 According to an embodiment of this invention, an energy-saving carbon dioxide heat pump includes a heat pump cycle system and a carbon dioxide scroll compressor 1.

[0020] The heat pump cycle system includes a carbon dioxide scroll compressor 1, a gas cooler, a throttling device, and an evaporator. The exhaust port 2 of the carbon dioxide scroll compressor 1 is connected to the inlet of the gas cooler via a high-pressure pipeline. The outlet of the gas cooler is connected to the inlet of the throttling device via a pipeline. The outlet of the throttling device is connected to the inlet of the evaporator via a pipeline. The outlet of the evaporator is connected to the suction port of the carbon dioxide scroll compressor 1 via a low-pressure pipeline, forming a closed transcritical carbon dioxide cycle loop. The carbon dioxide working fluid sequentially completes the processes of compression, heat release, throttling, and heat absorption in the cycle loop, realizing the heat transfer from a low-temperature heat source to a high-temperature heat source.

[0021] The carbon dioxide scroll compressor 1 includes a fixed scroll, a moving scroll 3, a frame, and a back pressure chamber. The fixed scroll is fixedly installed inside the compressor housing, and its bottom surface has fixed scroll teeth formed by scroll profiles. The moving scroll 3 is located below the fixed scroll, and its top surface has moving scroll teeth formed by scroll profiles. The moving scroll teeth mesh with the fixed scroll teeth to form multiple crescent-shaped compression chambers. The frame is located below the moving scroll 3 and supports it, guiding it in translational circular motion. The moving scroll 3 includes a base plate and moving scroll teeth on the top surface of the base plate.

[0022] The back pressure chamber is formed by the back side of the base plate of the moving scroll 3, the upper surface of the frame, an inner sealing ring, and an outer sealing ring. The inner sealing ring is installed in the inner groove on the upper surface of the frame and seals against the inner edge area of ​​the back side of the base plate of the moving scroll 3. The outer sealing ring is installed in the outer groove on the upper surface of the frame and seals against the outer edge area of ​​the back side of the base plate of the moving scroll 3. The back pressure chamber is an annular closed space used to contain back pressure gas and apply axial thrust to the base plate of the moving scroll 3.

[0023] A back pressure hole 4 is provided on the bottom plate of the moving scroll 3. The back pressure hole 4 penetrates the bottom plate of the moving scroll 3 and connects the intermediate pressure stage of the compression chamber with the back pressure chamber. There are two to four back pressure holes 4, which are evenly distributed along the circumference of the bottom plate of the moving scroll 3.

[0024] The throttling assembly is installed at each back pressure hole 4 on the base plate of the moving scroll 3. The throttling assembly includes a throttling orifice seat 5, a main throttling orifice 6, an auxiliary throttling orifice 7, an elastic valve plate 8, and a limiting component. The throttling orifice seat 5 is a cylindrical structure, embedded in the back pressure hole 4 of the base plate of the moving scroll 3. The outer circular surface of the throttling orifice seat 5 is either interference-fitted or threadedly fitted to the hole wall of the back pressure hole 4. The throttling orifice seat 5 has a main throttling orifice 6 and an auxiliary throttling orifice 7, both of which are through holes penetrating the throttling orifice seat 5, connecting the compression chamber and the back pressure chamber in parallel. The main throttling orifice 6 is located at the center of the throttling orifice seat 5, and the auxiliary throttling orifice 7 is located on the periphery of the main throttling orifice 6. The flow area of ​​the auxiliary throttling orifice 7 is two to four times that of the main throttling orifice 6.

[0025] The resilient valve plate 8 is a thin, elastic metal sheet fixed to the end face of the throttle orifice seat 5 facing the back pressure chamber. One end of the resilient valve plate 8 is a fixed end, which is fixed to the fixed seat on the end face of the throttle orifice seat 5 by rivets or screws; the other end of the resilient valve plate 8 is a free end, which covers the outlet of the auxiliary throttle orifice 7 in its natural state, blocking the auxiliary throttle orifice 7. A limiting member is fixed to the end face of the throttle orifice seat 5, located above the free end of the resilient valve plate 8. There is a preset gap between the limiting member and the resilient valve plate 8 to limit the maximum opening height of the resilient valve plate 8.

[0026] The main throttling orifice 6 remains open at all times and is unaffected by the elastic valve plate 8. The orifice diameter of the main throttling orifice 6 is determined by calculation based on the flow rate required to meet the back pressure chamber discharge demand under the compressor's maximum deceleration condition, ensuring that the gas in the back pressure chamber can be discharged in a timely manner during deceleration.

[0027] The back of the bottom plate of the moving vortex disk 3 is machined with an annular equalizing groove 9 and a radial distribution groove 10, which together form an equalizing groove network.

[0028] The annular equalizing groove 9 is a concentric annular groove formed on the back side of the bottom plate of the moving scroll 3, located within the back pressure cavity area. The radial position of the annular equalizing groove 9 corresponds to the installation position of each throttling orifice seat 5, so that the outlet of each throttling component faces the annular equalizing groove 9. The annular equalizing groove 9 extends continuously in the circumferential direction, forming a closed annular channel.

[0029] The radiation distribution groove 10 consists of multiple shallow grooves extending radially from the central region to the outer edge region on the back side of the driven vortex 3 base plate. The radiation distribution groove 10 is evenly distributed circumferentially, connecting the inner and outer edge regions of the annular equalizing groove 9 and the back pressure cavity. The radially inner end of the radiation distribution groove 10 extends to the inner edge of the annular equalizing groove 9 and communicates with the annular equalizing groove 9, while the radially outer end of the radiation distribution groove 10 extends to the outer edge region of the back pressure cavity.

[0030] The depth of the annular equalizing groove 9 is 0.5 to 1.5 mm, and the depth of the radial distribution groove 10 is 0.2 to 0.5 mm. The depth of the annular equalizing groove 9 is greater than the depth of the radial distribution groove 10, so that the annular equalizing groove 9 has a larger flow cross-section as the main channel for airflow distribution, and the radial distribution groove 10 has a smaller flow cross-section as the branch channel for airflow distribution, forming an airflow distribution network with a "main channel-branch channel" hierarchical structure.

[0031] When the compressor is running, a small gap is maintained between the back pressure chamber and the upper surface of the frame. The annular equalizing groove 9 and the radial distribution groove 10 on the back of the bottom plate of the moving scroll 3 together with the upper surface of the frame form an airflow distribution channel network.

[0032] In some embodiments, the elastic valve plate 8 is a stainless steel spring plate with a thickness of 0.1 to 0.3 mm, which can generate elastic deformation to open the auxiliary throttling orifice 7 when there is a preset pressure difference between the compression chamber and the back pressure chamber.

[0033] In some embodiments, the limiting member is an arc-shaped baffle fixed to the end face of the throttle seat 5, and the gap between the arc surface of the arc-shaped baffle and the upper surface of the free end of the elastic valve plate 8 is 0.3 to 0.8 mm.

[0034] In some embodiments, the number of throttling components is three, which are evenly distributed at 120 degrees along the circumference of the bottom plate of the moving scroll 3.

[0035] In some embodiments, the number of radiation distribution slots 10 is six to twelve, and the directional angles between adjacent radiation distribution slots 10 are equal.

[0036] Furthermore, in order to improve the sealing between the throttle hole seat 5 and the bottom plate of the moving scroll 3, a sealing ring is provided between the outer circular surface of the throttle hole seat 5 and the hole wall of the back pressure hole 4, and the sealing ring is embedded in the annular groove of the outer circular surface of the throttle hole seat 5.

[0037] Furthermore, in order to facilitate pressure equalization and gas mixing among the various throttling components, the width of the annular equalizing groove 9 is two to five millimeters, and the radial position of the annular equalizing groove 9 ensures that the outlets of each throttling component fall within the width range of the annular equalizing groove 9.

[0038] Furthermore, in order to shorten the path of gas transmission to the outer edge region of the back pressure cavity, the radiation distribution groove 10 is also provided with a bifurcated branch groove in the radially outer region. The bifurcated branch groove branches off from the middle section of the radiation distribution groove 10 and extends to both sides in the circumferential direction to increase the coverage of gas distribution.

[0039] Instructions for use; Step 1: Install each throttling component into the back pressure hole 4 of the bottom plate of the moving scroll 3, with the elastic valve plate 8 facing the back pressure cavity side, and the outlet of each throttling component facing the annular equalizing groove 9 on the back of the bottom plate of the moving scroll 3.

[0040] Step 2: Install the moving scroll 3 on the top of the frame. The inner and outer sealing rings seal and fit with the inner and outer edge areas of the back of the bottom plate of the moving scroll 3, respectively, to form a closed back pressure cavity. The annular equalizing groove 9 and the radiation distribution groove 10 on the back of the bottom plate of the moving scroll 3 together with the upper surface of the frame to form an airflow distribution network.

[0041] Step 3: When the compressor is running in steady state, the gas in the intermediate pressure stage of the compression chamber continuously enters the annular equalizing groove 9 through the main throttling orifice 6 of each throttling component; the elastic valve plate 8 maintains a certain balanced opening under the action of the steady-state pressure difference between the compression chamber and the back pressure chamber, and the auxiliary throttling orifice 7 is partially opened or closed.

[0042] Step four: The gas flows rapidly in the circumferential direction within the annular pressure equalization groove 9, achieving uniform circumferential pressure distribution among the various throttling components and forming a continuous annular pressure distribution zone.

[0043] Step 5: Gas is simultaneously distributed from the annular equalizing groove 9 to the inner and outer edge regions of the back pressure cavity through each radiation distribution groove 10, establishing a uniform pressure distribution within the back pressure cavity.

[0044] Step six: The gas pressure in the back pressure chamber acts on the back side of the bottom plate of the moving scroll 3, generating an axial thrust pointing in the direction of the fixed scroll, pushing the moving scroll 3 closer to the fixed scroll, thereby realizing the adaptive adjustment of the axial gap between the moving scroll 3 and the fixed scroll.

[0045] Step 7: When the compressor accelerates, the pressure in the intermediate pressure stage of the compression chamber rises rapidly, and the pressure difference between it and the back pressure chamber increases. The increased pressure difference pushes the elastic valve plate 8 to open further, the flow area of ​​the auxiliary throttling orifice 7 increases, and the gas rushes into the annular equalizing groove 9 at a large flow rate.

[0046] Step 8: The large flow of gas is rapidly mixed and pressure-equalized in the annular pressure equalization tank 9 along the circumference, and then distributed to each area of ​​the back pressure chamber through the radiation distribution tank 10, so that the overall pressure of the back pressure chamber rises rapidly and uniformly, and the moving vortex 3 obtains sufficient axial thrust in time to maintain the small gap between it and the stationary vortex.

[0047] Step 9: When the compressor decelerates, the pressure in the intermediate pressure stage of the compression chamber decreases, and the pressure difference between it and the back pressure chamber decreases. The elastic valve plate 8 falls back under its own elastic restoring force, and the auxiliary throttle orifice 7 closes or reduces its opening. The gas in the back pressure chamber can only be discharged to the compression chamber through the main throttle orifice 6.

[0048] Step 10: Since the diameter of the main throttle orifice 6 is determined according to the venting requirements of the maximum deceleration condition, the gas in the back pressure chamber can be discharged at an appropriate rate, the pressure in the back pressure chamber drops steadily, and the axial position of the moving scroll 3 transitions stably, avoiding scroll scraping caused by excessive back pressure.

[0049] In some embodiments, the preload of the elastic valve plate 8 in step three is determined based on the steady-state pressure difference between the intermediate pressure stage of the compression chamber and the back pressure chamber under the rated operating conditions of the compressor, so that the elastic valve plate 8 maintains a small opening under the rated operating conditions, and the auxiliary throttling orifice 7 is in a critically open state.

[0050] In some embodiments, the total flow area of ​​the auxiliary throttling orifice 7 after it is opened in steps seven and eight is three to five times the flow area of ​​the main throttling orifice 6, so that the pressure response speed of the back pressure chamber under acceleration conditions is increased to three to five times that when only the main throttling orifice 6 is present.

[0051] The energy-saving carbon dioxide heat pump of this embodiment solves two key bottlenecks in the back pressure response link by setting a throttling component with a main throttling orifice 6, an auxiliary throttling orifice 7 and an elastic valve plate 8 at the back pressure hole 4 position of the bottom plate of the moving scroll 3, and setting an equalizing groove network formed by an annular equalizing groove 9 and a radial distribution groove 10 on the back side of the bottom plate of the moving scroll 3, and adopting a coordinated strategy of "adaptive throttling and networked distribution".

[0052] To address the issue of throttling response lag, the elastic valve plate 8 automatically adjusts the opening of the auxiliary throttling orifice 7 based on the pressure difference between the compression chamber and the back pressure chamber, forming a negative feedback regulation. When the pressure response lag in the back pressure chamber leads to an increase in the pressure difference, the elastic valve plate 8 is pushed open by the pressure difference, increasing the opening of the auxiliary throttling orifice 7, thus increasing the gas flow area and accelerating the charging of the back pressure chamber. When the pressure difference decreases, the elastic valve plate 8 falls back under its own elastic restoring force, closing or reducing the opening of the auxiliary throttling orifice 7, leaving only the main throttling orifice 6 to maintain the venting capacity. The orifice diameter of the main throttling orifice 6 is determined to meet the venting requirements under maximum deceleration conditions, ensuring that the gas in the back pressure chamber can be discharged in a timely manner during deceleration, avoiding excessive back pressure that could cause the scroll plate to scrape. This "fast charging, slow discharging, but sufficient discharging" characteristic matches the actual requirements of scroll plate clearance control.

[0053] To address the issue of uneven pressure distribution, the annular pressure equalization groove 9 serves as a circumferentially connected pressure bus, aggregating the point source outputs of each throttling component and achieving circumferential pressure equalization. The radial distribution groove 10 acts as a pressure branch, simultaneously distributing the equalized gas to both the inner and outer edge regions of the back pressure chamber. This network structure transforms the gas transmission path from "point to surface" to "point to line to surface," shortening the equivalent transmission distance of the farthest region within the back pressure chamber. Each region responds to pressure changes almost synchronously, preventing the moving vortex 3 from tilting and oscillating due to uneven force.

[0054] The throttling component accelerates the response speed of gas entering the back pressure chamber, while the pressure equalizing network accelerates the homogenization speed of gas distribution within the chamber. The two are connected in series to form a complete fast response link. Therefore, when the carbon dioxide scroll compressor 1 of this embodiment is running under variable frequency conditions, the moving scroll 3 can quickly obtain sufficient axial support force during frequency switching, while maintaining uniform force to avoid tilting and swaying, resulting in more precise and stable axial clearance control.

[0055] Precise control of axial clearance reduces axial leakage losses in the compression chamber, improving compression efficiency; avoiding scroll scraping reduces frictional power consumption and mechanical energy loss. Both factors work together to improve the compressor's volumetric efficiency and isentropic efficiency. For a carbon dioxide heat pump system, improved compressor efficiency means lower energy consumption for the same heating demand, thus improving the overall energy efficiency ratio of the heat pump system and achieving the technical goal of energy-saving carbon dioxide heat pumps.

Claims

1. An energy-saving carbon dioxide heat pump, characterized in that, include: A heat pump cycle system, the heat pump cycle system comprising a carbon dioxide scroll compressor, a gas cooler, a throttling device and an evaporator connected in sequence through pipelines to form a closed loop; The carbon dioxide scroll compressor includes a fixed scroll, a moving scroll, a frame, and a back pressure chamber; the moving scroll includes a moving scroll base plate and moving scroll teeth disposed on the top surface of the moving scroll base plate, the moving scroll teeth meshing with the fixed scroll teeth of the fixed scroll to form a compression chamber; the back pressure chamber is formed by the space between the back surface of the moving scroll base plate and the upper surface of the frame; A back pressure hole is provided through the bottom plate of the moving scroll plate, and the back pressure hole connects the intermediate pressure stage of the compression chamber with the back pressure chamber; a differential pressure response throttling component is installed in the back pressure hole. The differential pressure responsive throttling assembly includes a throttling orifice seat, a normally open main throttling orifice, a variable flow area auxiliary throttling orifice, and a differential pressure driven elastic valve plate. The throttling orifice seat is fixed inside the back pressure orifice. The normally open main throttling orifice and the variable flow area auxiliary throttling orifice are connected in parallel inside the throttling orifice seat, connecting the compression chamber and the back pressure chamber. The differential pressure driven elastic valve plate is fixed to the side of the throttling orifice seat facing the back pressure chamber, and the free end of the differential pressure driven elastic valve plate blocks the outlet of the variable flow area auxiliary throttling orifice in its natural state. The back of the moving vortex base plate is provided with a circumferentially connected pressure equalization groove and a radially distributed distribution groove. The circumferentially connected pressure equalizing groove is an annular groove located within the back pressure cavity region; the radially distributed distribution groove extends from the circumferentially connected pressure equalizing groove to the inner and outer edge regions of the back pressure cavity.

2. The energy-saving carbon dioxide heat pump according to claim 1, characterized in that, The differential pressure driven elastic valve plate is an elastic metal sheet. One end of the differential pressure driven elastic valve plate is a fixed end, which is fixed to the fixed seat on the end face of the throttling orifice seat by fasteners, and the other end is a free end.

3. The energy-saving carbon dioxide heat pump according to claim 2, characterized in that, The differential pressure responsive throttling assembly also includes an opening limiter, which is fixed to the end face of the throttling orifice seat facing the back pressure chamber and located above the free end of the differential pressure driven elastic valve plate. There is a preset gap between the opening limiter and the differential pressure driven elastic valve plate.

4. The energy-saving carbon dioxide heat pump according to claim 3, characterized in that, The opening limiter is an arc-shaped baffle, and the arc surface of the arc-shaped baffle is positioned opposite to the upper surface of the free end of the differential pressure driven elastic valve plate.

5. The energy-saving carbon dioxide heat pump according to claim 1, characterized in that, The differential pressure responsive throttling components are multiple and are evenly distributed along the circumference of the moving vortex base plate; the radial position of the circumferentially connected pressure equalizing groove corresponds to the installation position of each differential pressure responsive throttling component, so that the outlet of each differential pressure responsive throttling component is directly opposite the circumferentially connected pressure equalizing groove.

6. The energy-saving carbon dioxide heat pump according to claim 5, characterized in that, The variable flow area auxiliary throttling orifice is located on the periphery of the normally open main throttling orifice, and the flow area of ​​the variable flow area auxiliary throttling orifice is larger than the flow area of ​​the normally open main throttling orifice.

7. The energy-saving carbon dioxide heat pump according to claim 1, characterized in that, The radially distributed distribution groove consists of multiple shallow grooves evenly distributed around the circumference of the bottom plate of the moving vortex disk. The radially inner end of the radially distributed distribution groove is connected to the circumferentially connected pressure equalization groove, and the radially outer end of the radially distributed distribution groove extends to the outer edge region of the back pressure cavity.

8. The energy-saving carbon dioxide heat pump according to claim 7, characterized in that, The depth of the circumferentially connected equalizing groove is greater than the depth of the radially distributed distribution groove. The circumferentially connected equalizing groove forms the main channel for airflow distribution, and the radially distributed distribution groove forms the branch channel for airflow distribution.

9. The energy-saving carbon dioxide heat pump according to claim 7, characterized in that, The radially distributed distribution slot has a branched branch slot in the radially outer region. The branched branch slot branches off from the middle section of the radially distributed distribution slot and extends to both sides in the circumferential direction.

10. The energy-saving carbon dioxide heat pump according to claim 1, characterized in that, The back pressure chamber is formed by the back side of the moving scroll base plate, the upper surface of the frame, the inner sealing ring, and the outer sealing ring. The inner sealing ring is installed in the inner groove on the upper surface of the frame and seals with the inner edge area of ​​the back side of the moving scroll base plate. The outer sealing ring is installed in the outer groove on the upper surface of the frame and seals with the outer edge area of ​​the back side of the moving scroll base plate.

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