Novel transcritical carbon dioxide energy efficiency enhancement device and refrigeration system
By using a combination of solenoid valves, three-way valves, and pressure exchangers in a transcritical carbon dioxide refrigeration system to control valve opening and switching, and recovering pressure work to pre-compress the evaporator return vapor, the energy efficiency loss caused by direct throttling and pressure reduction of high-pressure exhaust is solved, thereby improving the energy efficiency of the refrigeration system.
Patent Information
- Application Number
- CN202521286740.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-23
- Publication Date
- 2026-06-02
- Estimated Expiration
- 2035-06-23
AI Technical Summary
When a transcritical carbon dioxide refrigeration system operates above the critical point, the direct throttling and pressure reduction of the high-pressure exhaust leads to irreversible pressure loss and reduces system energy efficiency.
By employing a combination of solenoid valves, a first three-way valve, a second three-way valve, and a pressure exchanger, the pressure work is recovered to pre-compress the evaporator return steam by controlling the opening and switching of the valves, thereby reducing compressor energy consumption.
Without increasing additional energy consumption, the energy efficiency of the refrigeration system can be improved by reducing compressor energy consumption and enhancing system performance through the recovery of pressure work.
Smart Images
Figure CN224316452U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a carbon dioxide refrigeration device, and more particularly to a novel transcritical carbon dioxide energy efficiency enhancement device and refrigeration system. Background Technology
[0002] Currently, transcritical carbon dioxide refrigeration systems commonly employ direct high-pressure throttling of the high-pressure fluid after it has been cooled by a gas cooler following the discharge from the high-pressure compressor. The high-pressure compressor discharge, after being cooled by the gas cooler, becomes a high-pressure fluid with a temperature slightly higher than ambient temperature. This high-pressure fluid directly enters an electrically regulated high-pressure throttling valve for pressure reduction, thereby producing liquid carbon dioxide suitable for refrigeration and flash gas that needs to be discharged.
[0003] Problem: Because transcritical carbon dioxide refrigeration systems operate above the critical point with very high exhaust pressures (>=74 bar), while the liquid supply pressure of the receiver is typically around 30-40 bar. This leads to direct throttling and pressure reduction, resulting in an irreversible pressure loss of at least 30 bar, thus reducing the overall system energy efficiency. Utility Model Content
[0004] To address the aforementioned problems, this utility model provides a novel transcritical carbon dioxide energy efficiency enhancement device, the specific technical solution of which is as follows:
[0005] A novel transcritical carbon dioxide energy efficiency enhancement device includes: a solenoid valve located at the outlet of a gas cooler; a first three-way valve located between the inlet of the gas cooler and a liquid reservoir; a second three-way valve located between the liquid reservoir and a cryogenic evaporator; and a pressure exchanger, wherein the high-pressure output port A of the pressure exchanger is connected to the first three-way valve, the high-pressure input port B is connected to the solenoid valve, the low-pressure input port C is connected to the second three-way valve, and the low-pressure output port D is connected to the liquid inlet of the liquid reservoir.
[0006] Preferably, it further includes: a high-pressure throttle valve disposed between the liquid reservoir and the gas cooler, and the low-pressure output port disposed between the high-pressure throttle valve and the liquid reservoir.
[0007] A novel transcritical carbon dioxide refrigeration system includes: a novel transcritical carbon dioxide energy efficiency enhancement device.
[0008] Compared with the prior art, the present invention has the following beneficial effects:
[0009] This invention provides a novel transcritical carbon dioxide energy efficiency enhancement device that, without increasing additional energy consumption, recovers a portion of the pressure work of the transcritical carbon dioxide refrigeration system to pre-compress the evaporator return vapor, thereby reducing the energy consumption of the compressor and thus improving the energy efficiency of the refrigeration system. Attached Figure Description
[0010] Figure 1 This is a schematic diagram of the structure of a novel transcritical carbon dioxide energy efficiency enhancement device. Detailed Implementation
[0011] The present invention will now be further described with reference to the accompanying drawings.
[0012] like Figure 1 As shown, a novel transcritical carbon dioxide energy efficiency enhancement device includes a solenoid valve 3, a first three-way valve 1, a second three-way valve 2, and a pressure exchanger 4. The solenoid valve 3 is installed at the outlet of the gas cooler 62; the first three-way valve 1 is installed between the inlet of the gas cooler 62 and the liquid receiver 63; the second three-way valve 2 is installed between the liquid receiver 63 and the cryogenic evaporator 64; the high-pressure output port A of the pressure exchanger 4 is connected to the first three-way valve 1, the high-pressure input port B of the pressure exchanger 4 is connected to the solenoid valve 3, the low-pressure input port C of the pressure exchanger 4 is connected to the second three-way valve 2, and the low-pressure output port D of the pressure exchanger 4 is connected to the liquid receiver 63.
[0013] The high-pressure throttle valve 5 is installed between the liquid reservoir 63 and the gas cooler 62, and the low-pressure output port D is located between the high-pressure throttle valve 5 and the liquid reservoir 63.
[0014] Pressure exchanger 4 is a commercially available product.
[0015] A pressure exchanger 4 is installed at the outlet of the gas cooler 62 of the transcritical carbon dioxide refrigeration system. The system energy efficiency is improved by controlling the opening and closing of the solenoid valve 3 and the switching of the first three-way valve 1 and the second three-way valve 2.
[0016] When the system operates in transcritical mode, solenoid valve 3 opens; ports 11 and 12 of the first three-way valve 1 are connected; ports 21 and 22 of the second three-way valve 2 are connected, guiding the high-pressure carbon dioxide fluid from gas cooler 62 into the pressure-reducing side of pressure exchanger 4. This causes the fluid to expand under reduced pressure within the hollow cavity of the rotor core of pressure exchanger 4, thereby rotating the rotor of pressure exchanger 4. This, in turn, compresses the carbon dioxide flash gas from receiver 63 within the other cavity, increasing its pressure before it enters the inlet of gas cooler 62 for cooling. Because a portion of the pressure energy of the high-pressure fluid is exchanged with the flash gas, it reaches a high-pressure state upon passing through pressure exchanger 4, thus reducing the work done by the medium-temperature compressor, reducing compressor energy consumption, and consequently improving the energy efficiency of the entire refrigeration system.
[0017] When the system operates in subcritical mode, solenoid valve 3 opens; ports 11 and 13 of the first three-way valve 1 are connected; ports 22 and 23 of the second three-way valve 2 are connected, guiding the high-pressure carbon dioxide fluid from gas cooler 62 into the pressure-reducing side of pressure exchanger 4. After pressure reduction and expansion, it enters liquid receiver 63. On the other side of pressure exchanger 4, low-pressure carbon dioxide gas from cryogenic evaporator 64 is compressed before entering liquid receiver 63. This reduces the work done by the cryogenic compressor, reduces energy consumption, and improves system energy efficiency.
[0018] When the system is operating in subcritical mode and the low-temperature evaporator 64 is not in operation, the solenoid valve 3 is closed.
[0019] A novel transcritical carbon dioxide refrigeration system includes: a novel transcritical carbon dioxide energy efficiency enhancement device.
[0020] The novel transcritical carbon dioxide refrigeration system also includes a low-temperature carbon dioxide compressor 68, a medium-temperature carbon dioxide compressor 61, a low-temperature evaporator 64, a medium-temperature evaporator 65, a low-temperature expansion valve 66, a medium-temperature expansion valve 67, and a flash bypass valve 69. The novel transcritical carbon dioxide refrigeration system is an existing mature system and will not be described in detail here.
[0021] The technical principles of this utility model have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of this utility model and should not be construed as limiting the scope of protection of this utility model in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of this utility model without inventive effort, and these embodiments will all fall within the protection scope of the claims of this utility model.
Claims
1. A novel transcritical carbon dioxide energy efficiency enhancement device, characterized in that, include: Solenoid valve (3) is located at the outlet of gas cooler (62); The first three-way valve (1) is located between the air inlet of the gas cooler (62) and the liquid reservoir (63); A second three-way valve (2) is located between the liquid reservoir (63) and the low-temperature evaporator (64); and The pressure exchanger (4) has a high pressure output port A connected to the first three-way valve (1), a high pressure input port B connected to the solenoid valve (3), a low pressure input port C connected to the second three-way valve (2), and a low pressure output port D connected to the liquid inlet of the liquid reservoir (63).
2. The novel transcritical carbon dioxide energy efficiency enhancement device according to claim 1, characterized in that, Also includes: A high-pressure throttle valve (5) is located between the liquid reservoir (63) and the gas cooler (62), and the low-pressure output port D is located between the high-pressure throttle valve (5) and the liquid reservoir (63).
3. A novel transcritical carbon dioxide refrigeration system, characterized in that, include: The novel transcritical carbon dioxide energy efficiency enhancement device according to claim 1.