A food fast low-temperature storage system based on reverse brayton cycle
The reverse Brayton cycle food rapid low-temperature storage system, utilizing two-stage compression and mechanical work recovery, solves the problems of traditional refrigerant pollution and slow freezing speed, achieving efficient low-temperature storage and environmental protection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NORTHWEST A & F UNIV
- Filing Date
- 2025-03-04
- Publication Date
- 2026-07-14
AI Technical Summary
In existing technologies, traditional refrigerants pollute the environment and cannot achieve rapid low-temperature cooling, leading to food quality deterioration and spoilage during long-distance transportation. Traditional reverse Brayton refrigeration systems have insufficient pressure ratios and cannot effectively utilize mechanical work.
The food rapid low-temperature storage system based on the reverse Brayton cycle includes components such as a first centrifugal compressor, a water cooling device, a heat exchanger, and a turbine expander. It recovers mechanical work through two-stage compression and coaxial arrangement, and uses oil-free air suspension bearings to achieve efficient low-temperature refrigeration.
It significantly improves freezing speed, maintains food quality, avoids toxic refrigerant contamination, protects the environment, and achieves efficient low-temperature storage.
Smart Images
Figure CN224498797U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a rapid low-temperature food storage system based on the reverse Brayton cycle, belonging to the field of low-temperature refrigeration technology. Background Technology
[0002] Globalization has accelerated international trade, leading to increasingly frequent food trade. However, long-distance transportation, due to changes in time and environment, fluctuations in microorganisms, enzymes, and temperature and humidity can easily lead to bacterial growth and the formation of sulfur compounds, causing a decline in food quality, changes in taste, and even spoilage. Ensuring food freshness during transportation has become a critical issue that urgently needs to be addressed. The current internationally accepted solution is to create a low-temperature environment to inhibit microbial growth, reduce enzyme activity, and minimize chemical reactions in food, thereby preserving its original color, aroma, flavor, and nutritional value. This necessitates the use of rapid freezing technology.
[0003] In the field of rapid freezing technology for food, the traditional refrigeration technology using chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) refrigerants is currently the most widely used. These refrigerants can pollute the environment and cannot meet the requirements for low refrigeration temperatures and rapid cooling.
[0004] Traditional reverse Brayton refrigeration systems using single-stage centrifugal compressors cannot provide a large pressure ratio, thus failing to achieve low turbine expander outlet temperatures. Furthermore, the mechanical work output by turbine expanders with conventional connection methods cannot be effectively utilized during operation. Utility Model Content
[0005] This invention provides a rapid low-temperature food storage system based on the reverse Brayton cycle, which can effectively solve the problems of food quality decline, taste changes and spoilage caused by slow freezing speed. At the same time, it can avoid the use of toxic refrigerants and protect the environment.
[0006] To address the aforementioned technical problems, this utility model discloses a rapid low-temperature food storage system based on the reverse Brayton cycle, comprising a first centrifugal compressor, a water-cooling device, a first heat exchanger, a second centrifugal compressor, a second heat exchanger, a third heat exchanger, a gas storage tank, a ball valve, an electro-proportional valve, a refrigerated air dryer, a turbo expander, a throttling valve, and a cold box. The first and second centrifugal compressors operate under the drive of a motor. Air from the environment enters the first centrifugal compressor for a first adiabatic compression, and is cooled by the water-cooling device through the first heat exchanger. It then enters the second centrifugal compressor for a second adiabatic compression, and is cooled again by the water-cooling device through the second heat exchanger. The lower-temperature gas then enters the gas storage tank through the third heat exchanger. The ball valve and electro-proportional valve can adjust the flow rate of the air output from the gas storage tank to meet different cooling requirements. The refrigerated air dryer can absorb air... Moisture in the air is removed to ensure the normal operation of the turbine expander. In the turbine expander, the air undergoes adiabatic expansion to obtain low-temperature air. The throttling valve further reduces the gas temperature to meet even lower refrigeration requirements. The cold box receives low-temperature air and discharges the original room-temperature air. With a large airflow, a low-temperature environment can be quickly created. The discharged gas can be further cooled by the third heat exchanger at the outlet of the second centrifugal compressor before being discharged into the environment. The first centrifugal compressor, the second centrifugal compressor, the turbine expander, and the motor are arranged coaxially, effectively recovering and utilizing the mechanical work output by the turbine expander, and making the entire system structure compact. Two-stage compression increases the pressure ratio and reduces the outlet temperature of the turbine expander. Air bearings are used to fix the first centrifugal compressor, the second centrifugal compressor, and the turbine expander, making the entire system oil-free, highly efficient, and with low vibration.
[0007] As a preferred technical solution of this utility model, the entire system operates in an oil-free environment and can input clean, low-temperature air into the cold box.
[0008] As a preferred technical solution of this utility model, the interstage water cooling scheme between the first centrifugal compressor and the second centrifugal compressor effectively reduces the outlet temperature of the compressor and improves the compression efficiency of the compressor.
[0009] As a preferred embodiment of this invention, the throttle valve can further reduce the temperature of the gas to provide a lower cooling temperature.
[0010] As a preferred technical solution of this utility model, the system is an open-loop system, which makes the system structure simpler. The air source is air from the natural environment, and at the same time, it can ensure that the inlet temperature of the first compressor is room temperature.
[0011] The beneficial effects achieved by this invention are as follows: This rapid low-temperature food storage system based on the reverse Brayton cycle can significantly improve the freezing speed, thereby effectively avoiding problems such as decreased food quality, changes in taste, and spoilage caused by bacterial growth due to a slow freezing process. By accelerating freezing, the nutritional components and freshness of food can be maintained, ensuring high quality during long-term storage. Simultaneously, this method eliminates the need for toxic chemical refrigerants in traditional refrigeration processes, reducing environmental pollution and greenhouse gas emissions, thus effectively protecting the ecological environment while ensuring food safety. Attached Figure Description
[0012] The accompanying drawings are provided to further understand the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation thereof.
[0013] Figure 1 This is a system flow diagram of a rapid low-temperature food storage system based on the reverse Brayton cycle according to this utility model.
[0014] In the diagram: 1. First centrifugal compressor; 2. Water cooling device; 3. First heat exchanger; 4. Second centrifugal compressor; 5. Second heat exchanger; 6. Third heat exchanger; 7. Air tank; 8. Ball valve; 9. Electro-proportional valve; 10. Refrigerated air dryer; 11. Turbine expander; 12. Throttling valve; 13. Cold box. Detailed Implementation
[0015] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.
[0016] like Figure 1As shown, this utility model provides a rapid low-temperature food storage system based on the reverse Brayton cycle, including a first centrifugal compressor 1, a water-cooling device 2, a first heat exchanger 3, a second centrifugal compressor 4, a second heat exchanger 5, a third heat exchanger 6, a gas storage tank 7, a ball valve 8, an electro-proportional valve 9, a refrigerated air dryer 10, a turbo expander 11, a throttle valve 12, and a cold box 13. The first centrifugal compressor 1 and the second centrifugal compressor 4 start operating under the drive of a motor. Air from the environment enters the first centrifugal compressor 1 for the first adiabatic compression, and is cooled by the first heat exchanger 3 under the action of the water-cooling device 2. Then, it enters the second centrifugal compressor 4 for the second adiabatic compression, and is cooled by the second heat exchanger 5 under the action of the water-cooling device 2. The lower-temperature gas then enters the gas storage tank 7 through the third heat exchanger 6. The ball valve 8 and the electro-proportional valve 9 can adjust the flow rate of the air output from the gas storage tank 7 to meet different cooling needs. The refrigerated air dryer 10 can... The turbine expander 11 absorbs moisture from the air to ensure its normal operation. In the turbine expander 11, the air undergoes adiabatic expansion to obtain low-temperature air. The throttle valve 12 further reduces the gas temperature to meet even lower refrigeration requirements. The cold box 13 inputs low-temperature air and discharges the original room-temperature air. When the airflow is large, a low-temperature environment can be quickly created. The discharged gas can be further cooled by the third heat exchanger 6, and then discharged into the environment. The first centrifugal compressor 1, the second centrifugal compressor 4, the turbine expander 11, and the motor are arranged coaxially, effectively recovering and utilizing the mechanical work output by the turbine expander 11, and making the entire system structure compact. Two-stage compression increases the pressure ratio and reduces the outlet temperature of the turbine expander 11. Air suspension bearings are used to fix the first centrifugal compressor 1, the second centrifugal compressor 4, and the turbine expander 11, giving the entire system oil-free operation, high efficiency, and low vibration.
[0017] The working principle of this invention is as follows: During operation, the first centrifugal compressor 1 and the second centrifugal compressor 4 start running under the drive of a motor. Ambient air enters the first centrifugal compressor 1 for the first adiabatic compression, and is cooled by the first heat exchanger 3 under the action of the water cooling device 2. Then, it enters the second centrifugal compressor 4 for the second adiabatic compression, and is cooled again by the second heat exchanger 5 under the action of the water cooling device 2. The lower-temperature gas then enters the air storage tank 7 through the third heat exchanger 6. The ball valve 8 and the electro-proportional valve 9 can adjust the flow rate of the air output from the air storage tank 7 to meet different cooling needs. The refrigerated air dryer 10 absorbs moisture from the air to ensure the normal operation of the turbine expander 11. In the turbine expander 11, the air undergoes adiabatic expansion to obtain low-temperature air. The throttle valve 12 can further reduce the gas temperature to meet even lower cooling requirements. In the cold box 13, low-temperature air is input, and the original room-temperature air is discharged. When the air flow rate is large, a low-temperature environment can be quickly created. The discharged gas can be further cooled by the third heat exchanger 6, and then the air is discharged into the environment.
[0018] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A fast low temperature food storage system based on reverse Brayton cycle, comprising a first centrifugal compressor (1), a water cooling device (2), a first heat exchanger (3), a second centrifugal compressor (4), a second heat exchanger (5), a third heat exchanger (6), a gas storage tank (7), a ball valve (8), an electric proportional valve (9), a refrigerated air dryer (10), a turbine expander (11), a throttle valve (12), a cold box (13); characterized in that, The first centrifugal compressor (1) and the second centrifugal compressor (4) start to operate under the drive of the motor. The air in the environment enters the first centrifugal compressor (1) for the first adiabatic compression. It is cooled by the first heat exchanger (3) under the action of the water cooling device (2). Then it enters the second centrifugal compressor (4) for the second adiabatic compression. It is cooled by the second heat exchanger (5) under the action of the water cooling device (2). The lower temperature gas enters the gas storage tank (7) through the third heat exchanger (6). The ball valve (8) and the electric proportional valve (9) can adjust the flow rate of the air output from the gas storage tank (7) to meet different cooling needs. The refrigerated air dryer (10) can absorb the moisture in the air to ensure the normal operation of the turbine expander (11). The air undergoes adiabatic expansion in the turbine expander (11) to obtain low temperature air. The throttle valve (12) The temperature of the gas can be further reduced to meet the refrigeration requirements at lower temperatures. In the cold box (13), low-temperature air is introduced and the original room-temperature air is discharged. When the air flow rate is large, a low-temperature environment can be quickly created. The discharged gas can be further cooled by the third heat exchanger (6) and then the air is discharged into the environment. The first centrifugal compressor (1), the second centrifugal compressor (4), the turbine expander (11) and the motor are arranged in a coaxial manner, which effectively recovers and utilizes the mechanical work output by the turbine expander (11) and makes the entire system structure compact. The pressure ratio is increased by two-stage compression, and the outlet temperature of the turbine expander (11) is reduced. The first centrifugal compressor (1), the second centrifugal compressor (4) and the turbine expander (11) are fixed by air suspension bearings, so that the entire system has the characteristics of being oil-free, highly efficient and with low vibration.
2. The rapid low-temperature food storage system based on the reverse Brayton cycle according to claim 1, characterized in that, The entire system operates in an oil-free environment and can introduce clean, low-temperature air into the cold box.
3. The rapid low-temperature food storage system based on the reverse Brayton cycle according to claim 1, characterized in that, The interstage water cooling scheme between the first centrifugal compressor (1) and the second centrifugal compressor (4) effectively reduces the outlet temperature of the compressor and improves the compression efficiency of the compressor.
4. The rapid low-temperature food storage system based on the reverse Brayton cycle according to claim 1, characterized in that, The throttle valve (12) can further reduce the temperature of the gas to provide a lower cooling temperature.
5. A rapid low-temperature food storage system based on the reverse Brayton cycle according to claim 1, characterized in that, The system is an open-loop system, which simplifies the system structure. The air source is natural air, and it can ensure that the inlet temperature of the first compressor is at room temperature.