Parallel compression device of carbon dioxide pressurization refrigeration system
By using gas and liquid injectors in the CO2 transcritical booster refrigeration system to work in conjunction with parallel compressors, the pressure loss caused by high pressure and flash gas throttling in the system is solved, and the energy efficiency of the system is improved.
Patent Information
- Application Number
- CN202421962211.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-14
- Publication Date
- 2025-05-27
- Estimated Expiration
- 2034-08-14
AI Technical Summary
When the CO2 transcritical boosting refrigeration system works above the critical point, there are pressure losses caused by high-pressure throttling and flash air throttling, which reduces the energy efficiency of the entire system.
The gas ejector and liquid ejector are used to work in conjunction with the parallel compressor, and the suction pressure of the medium-temperature compressor is increased through gaseous and liquid ejection, reducing the throttling loss, and reducing the heat exchange temperature difference of the medium-temperature evaporator.
It effectively reduces the throttling loss of high pressure and flash air, increases the suction pressure of the medium-temperature compressor, saves the compressor's work, and thus improves the energy efficiency of the system.
Smart Images
Figure CN222912014U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a carbon dioxide boosting refrigeration system, in particular to a parallel compression device of the carbon dioxide boosting refrigeration system. Background Art
[0002] Currently CO 2 Transcritical boost refrigeration systems are commonly used for high-pressure CO 2 The fluid is directly throttled by a high-pressure throttle valve to produce liquid and flash gas. The liquid part is sent to the evaporator through a pipeline for refrigeration. The flash gas left in the liquid storage needs to be throttled and reduced in pressure again through a flash gas throttle valve, and then enters the suction side of the medium-temperature compressor, mixes with the exhaust gas of the low-temperature compressor, and is compressed by the medium-temperature compressor. Problems with this method:
[0003] Due to CO 2 When the transcritical boost refrigeration system works above the critical point, the exhaust pressure is very high (≥74bar), while the supply pressure of the liquid reservoir is generally 30-40bar. Therefore, the use of direct high-pressure throttling will lead to an irreversible pressure loss of at least 30bar due to throttling and pressure reduction. At the same time, the flash gas of the liquid reservoir is throttled directly from about 40bar to the suction pressure of the medium-temperature compressor, and the pressure loss is also about 20bar. The secondary throttling and pressure reduction reduces the energy efficiency of the entire system. Utility Model Content
[0004] In order to solve the problem that the energy efficiency of the whole system is reduced due to the large pressure loss, the utility model provides a parallel compression device for a carbon dioxide booster refrigeration system. The specific technical solution is as follows:
[0005] A parallel compression device for a carbon dioxide boosted refrigeration system comprises: a parallel compressor, wherein a parallel air outlet and a parallel air inlet of the parallel compressor are respectively connected to a cooling air inlet of a gas cooler and a liquid storage air outlet of a liquid reservoir of the carbon dioxide boosted refrigeration system; a gas ejector, respectively connected to the cooling air outlet of the gas cooler and the liquid storage air inlet of the liquid reservoir; and a liquid ejector, respectively connected to a liquid separation outlet of a gas-liquid separator of the carbon dioxide boosted refrigeration system and a liquid storage air inlet of the liquid reservoir.
[0006] Compared with the prior art, the utility model has the following beneficial effects:
[0007] The utility model provides a parallel compression device for a carbon dioxide booster refrigeration system, which adopts a gas ejector and a liquid ejector to work in conjunction with a parallel compressor, effectively reducing the throttling loss of high pressure and flash gas, while reducing the heat exchange temperature difference of the medium-temperature evaporator, increasing the suction pressure of the medium-temperature compressor, saving the work of the compressor, and thus improving the energy efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Figure 1 This is the structural schematic diagram of the present application. Detailed implementation manners
[0009] The present utility model will be further described below in conjunction with the accompanying drawings.
[0010] As Figure 1 shown, a parallel compression device of a carbon dioxide boosting refrigeration system includes: a parallel compressor 13, a gas ejector 8 and a liquid ejector 7; the parallel outlet and the parallel inlet of the parallel compressor 13 are respectively connected to the cooling inlet of a gas cooler 6 and the liquid outlet of a liquid storage tank 4 of the carbon dioxide boosting refrigeration system; the gas ejector 8 is respectively connected to the cooling outlet of the gas cooler 6 and the liquid inlet of the liquid storage tank 4; the liquid ejector 7 is respectively connected to the liquid outlet separated by a gas-liquid separator 3 and the liquid inlet of the liquid storage tank 4 of the carbon dioxide boosting refrigeration system.
[0011] The carbon dioxide boosting refrigeration system includes a low-temperature compressor 11, a medium-temperature compressor 12, a gas cooler 6, a liquid storage tank 4, a flash gas bypass valve 5, a gas-liquid separator 3, a medium-temperature evaporator 21, a medium-temperature expansion valve 31, a low-temperature expansion valve 32 and a low-temperature evaporator 22. The medium-temperature exhaust port of the medium-temperature compressor 12 is connected to the cooling inlet of the gas cooler 6, the cooling outlet of the gas cooler 6 is connected to the liquid inlet of the liquid storage tank 4, the liquid outlet of the liquid storage tank 4 is connected to the flash gas bypass valve 5, and the flash gas bypass valve 5 is connected to the medium-temperature inlet of the medium-temperature compressor 12. The liquid outlet of the liquid storage tank 4 is respectively connected to the medium-temperature expansion valve 31 and the low-temperature expansion valve 32, the medium-temperature expansion valve 31 is connected to the medium-temperature evaporator 21, and the medium-temperature evaporator 21 is connected to the separation inlet of the gas-liquid separator 3; the low-temperature expansion valve 32 is connected to the low-temperature evaporator 22, the low-temperature evaporator 22 is connected to the low-temperature inlet of the low-temperature compressor 11, and the low-temperature exhaust port of the low-temperature compressor 11 is connected to the medium-temperature inlet of the medium-temperature compressor 12.
[0012] The gas ejector 8 uses the high-pressure fluid cooled by the gas as the ejector flow and the gas from the outlet of the gas-liquid separator 3 after the medium-temperature evaporator 21 as the ejected flow. The gas ejector 8 ejects the gas at the outlet of the medium-temperature evaporator 21 through the high-pressure fluid, so as to increase the pressure of the final mixed gas to the internal pressure of the liquid storage tank 4; the liquid ejector 7, with the help of an electronic expansion valve and its controller, sets the superheat degree at the outlet of the medium-temperature evaporator 21 to 0-1K to ensure that the outlet of the medium-temperature evaporator 21 is in a gas-liquid two-phase state. Thus, the heat transfer temperature difference of the medium-temperature evaporator 21 can be reduced, and the suction pressure of the medium-temperature compressor 12 can be increased by 3-5 bar. The two-phase flow at the outlet of the medium-temperature evaporator 21 enters the gas-liquid separator 3, the liquid is stored at the bottom of the gas-liquid separator 3, and after being ejected by the liquid ejector 7, the pressure is increased to the liquid storage tank 4.
[0013] Due to the increase in the suction pressure of the medium-temperature compressor 12 and the decrease in the gas volume, some of the originally configured medium-temperature compressors 12 no longer need to operate on the medium-temperature side. The suction pipeline of the medium-temperature compressor 12 can be changed to the outlet of the liquid receiver 4, so that it can be functionally transformed into a parallel compression compressor. Since the suction pressure of the parallel compressor 13 is 10 - 20 bar higher than the previous medium-temperature suction pressure at the pressure of the liquid receiver 4, the power consumption of the compressor can be significantly reduced compared with the previous situation. The gas and liquid ejector 7 works in cooperation with the parallel compressor 13, effectively reducing the throttling losses of the high pressure and flash gas. At the same time, the heat transfer temperature difference of the medium-temperature evaporator 21 is reduced, the suction pressure of the medium-temperature compressor 12 is increased, the work done by the compressor is saved, and thus the energy efficiency of the system is improved.
[0014] The technical principle of the present utility model has been described above in combination with specific embodiments. These descriptions are only for explaining the principle of the present utility model and cannot be interpreted in any way as a limitation on the protection scope of the present utility model. Based on the explanations herein, those skilled in the art can readily conceive of other specific embodiments of the present utility model without creative efforts, and these embodiments will all fall within the protection scope of the claims of the present utility model.
Claims
1. A parallel compression device for a carbon dioxide booster refrigeration system, characterized in that: include: A parallel compressor (13), wherein a parallel air outlet and a parallel air inlet of the parallel compressor (13) are respectively connected to a cooling air inlet of a gas cooler (6) of a carbon dioxide boost refrigeration system and a liquid storage air outlet of a liquid storage device (4); a gas ejector (8) connected to the cooling gas outlet of the gas cooler (6) and the liquid storage gas inlet of the liquid storage device (4), respectively; and The liquid ejector (7) is respectively connected to the liquid separation outlet of the gas-liquid separator (3) of the carbon dioxide boost refrigeration system and the liquid storage air inlet of the liquid storage device (4).