Refrigeration unit that can meet wide temperature requirements in refrigerated compartments

Abstract

The present invention provides a refrigeration unit that can achieve the wide range temperature requirements in the refrigerated compartment, including a normal refrigeration unit, an ultra-low temperature auxiliary refrigeration unit and a heat exchanger. The normal refrigeration unit and the ultra-low temperature auxiliary refrigeration unit are respectively equipped with evaporators. The refrigerant after heat release and refrigeration by the condenser in the normal refrigeration unit is output in two ways. The first way is delivered to the first evaporator through the first stop valve and the first thermal expansion valve, and the second way is delivered to the first heat exchange path of the heat exchanger through the second stop valve and the second thermal expansion valve. In the ultra-low temperature auxiliary refrigeration unit, the condenser is replaced by a heat exchanger, and the refrigerant in the ultra-low temperature auxiliary refrigeration unit flows through the second heat exchange path of the heat exchanger to release heat. The unit is equipped with an additional ultra-low temperature auxiliary refrigeration unit and relies on the refrigeration of the normal refrigeration unit for heat dissipation, thereby widening the temperature range of the refrigerated vehicle, playing the role of ultra-low temperature refrigeration under special circumstances, and improving the matching degree of the product to special needs.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration of refrigerated vehicles, and in particular to a refrigeration unit capable of meeting temperature requirements of a wide range in a refrigerated vehicle compartment. Background Art

[0002] At present, refrigerated transport refrigeration equipment has been widely used in refrigerated transport vehicles of various specifications and models. The common cargo temperatures in the market are mostly refrigerated 2℃ to 8℃ and frozen -15℃ to -20℃. Conventional refrigerated refrigeration units can basically meet the cargo temperature requirements.

[0003] However, for goods that exceed the general transportation temperature standards, the temperature in the refrigerated compartment needs to be controlled within the required range throughout the entire process. However, from an economic perspective, the proportion of goods with special temperature requirements in the total refrigerated market is not high. If the refrigerated transport refrigeration unit equipped with the refrigerated vehicle is specially designed with a dedicated refrigeration system for special temperature requirements, the economy will be very poor, which is not conducive to the operation of the transportation company. However, conventional refrigeration refrigeration units cannot meet the lower temperature requirements required by customers, and cannot be transported, resulting in customers having to find another carrier, resulting in a poor customer experience.

[0004] Therefore, from the perspective of functionality and economy, a refrigeration unit is needed that can achieve the wide range of temperature requirements in the refrigerated compartment. It can not only meet the requirements when transporting conventional refrigerated goods, but also meet the requirements of goods when ultra-low temperature requirements are required.

[0005] At present, there are some ultra-low temperature transportation equipment on the market, which is equivalent to placing an ultra-low temperature special equipment in a refrigerated compartment for transportation. This transportation method is not only inefficient, but the ultra-low temperature special equipment cannot be powered on during the transportation, which will also lead to uncontrollable temperature during the transportation process, bringing risks to the transportation quality of ultra-low temperature goods. In addition, due to its bulky size and occupying too much space, the structure of the entire vehicle is not simple, which is a helpless move to deal with existing problems.

[0006] Therefore, a refrigeration unit that can meet the wide temperature requirements in the refrigerated compartment is very important for the refrigerated special vehicles on the current market.

[0007] In order to solve the above problems, people have been seeking an ideal technical solution. Summary of the invention

[0008] The purpose of the present invention is to address the deficiencies of the prior art and to provide a refrigeration unit that can meet both the temperature requirements under normal conditions and the requirements of ultra-low temperature goods, and has a relatively lower modification cost and meets the economic requirements and can achieve a wide range of temperature requirements in a refrigerated compartment.

[0009] The general idea of ​​this application is to add a set of ultra-low temperature auxiliary refrigeration unit to the original refrigeration unit. It uses the refrigeration capacity of the original refrigeration unit to dissipate heat and cool the refrigerant, and is equipped with a refrigerant with better performance. When ultra-low temperature is required, it can be started to achieve ultra-low temperature refrigeration. Since the transformation is based on the original refrigeration unit, the cooling capacity is a superimposed effect. Compared with the addition of dedicated special equipment, the structural optimization degree is higher, the additional components are limited, the effect is better, and it meets the functional and economic requirements.

[0010] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a refrigeration unit that can achieve the temperature requirements of a wide range in a refrigerated compartment, including a normal refrigeration unit, an ultra-low temperature auxiliary refrigeration unit and a heat exchanger, the normal refrigeration unit and the ultra-low temperature auxiliary refrigeration unit are respectively equipped with evaporators, and the refrigerant in the normal refrigeration unit after heat release and refrigeration by the condenser is output in two ways, the first way is transported to the first evaporator through the first stop valve and the first thermal expansion valve, and the second way is transported to the first heat exchange path of the heat exchanger through the second stop valve and the second thermal expansion valve, the condenser in the ultra-low temperature auxiliary refrigeration unit is replaced by the heat exchanger, and the refrigerant in the ultra-low temperature auxiliary refrigeration unit flows through the second heat exchange path of the heat exchanger for heat release process.

[0011] Based on the above, the heat exchanger is a plate heat exchanger or a tube heat exchanger.

[0012] Based on the above, the refrigerant in the normal refrigeration unit is R404a, and the refrigerant in the ultra-low temperature auxiliary refrigeration unit is R507a.

[0013] Based on the above, the normal refrigeration unit includes a compressor, a first oil-gas separator, a condenser, the first stop valve, the second stop valve, the first thermal expansion valve, the second thermal expansion valve, a first evaporator, a first heater, a second heater, a first liquid reservoir and a first gas-liquid separator. The exhaust port of the compressor is sequentially connected to the first oil-gas separator, the condenser and the first liquid reservoir, and the outlet of the first liquid reservoir is divided into two outputs:

[0014] The first path is delivered to the first evaporator through the first stop valve and the first thermal expansion valve, and the circuit of the first evaporator flows back to the compressor through the first gas-liquid separator;

[0015] The second path is delivered to the first heat exchange path of the heat exchanger through the second stop valve and the second thermal expansion valve, and the circuit of the first heat exchange path flows back to the compressor through the first gas-liquid separator;

[0016] The first heater and the second heater are both installed in the first evaporator.

[0017] Based on the above, the compressor includes a road compressor and a first electric compressor, and the road compressor and the first electric compressor are arranged in parallel at the front end of the first oil-gas separator, and the road compressor and the first electric compressor are connected to the input end of the first oil-gas separator through a one-way valve respectively, and the oil return port of the oil-gas separator is connected to the first electric compressor and the road compressor respectively, and the outlet of the first gas-liquid separator is also connected to the first electric compressor and the road compressor respectively.

[0018] Based on the above, the ultra-low temperature auxiliary refrigeration unit includes a second electric compressor, a second oil-gas separator, a third thermal expansion valve, a fourth thermal expansion valve, a second evaporator, a third evaporator, a second gas-liquid separator and a fourth stop valve. The exhaust port of the second electric compressor passes through the second oil-gas separator, the second heat exchange passage of the heat exchanger and the fourth stop valve in sequence, and is divided into two paths, which flow into the second evaporator through the third thermal expansion valve and into the third evaporator through the fourth thermal expansion valve respectively. The outlets of the second evaporator and the third evaporator are merged and flow into the inlet of the second gas-liquid separator. The outlet of the second gas-liquid separator flows back to the second electric compressor, and the oil return port of the second oil-gas separator flows back to the second electric compressor.

[0019] Based on the above, the ultra-low temperature auxiliary refrigeration unit also includes a liquid storage barrel and a third stop valve. The outlet end of the heat exchanger is connected to the inlet of the liquid storage barrel through the third stop valve and a pipeline. The outlet of the liquid storage barrel is connected to the inlet of the fourth stop valve. The liquid storage barrel stores R507a refrigerant.

[0020] Based on the above, a temperature sensor and a heat exchange pipeline are installed in the liquid storage barrel, the outlet end of the heat exchange pipeline is connected to the inlet end of the first gas-liquid separator, and the outlet end of the first liquid storage is connected to the inlet end of the heat exchange pipeline through the fifth stop valve and the thermal expansion valve;

[0021] The temperature sensor is associated with the fifth stop valve, the second stop valve and the compressor of the normal refrigeration unit. When the temperature in the liquid storage barrel exceeds the set value, the compressor is controlled to be turned on, the second stop valve is closed, and the fifth stop valve is opened to cool the refrigerant in the liquid storage barrel through the heat exchange pipeline.

[0022] Based on the above, the road compressor is installed on the chassis of the refrigerated truck near the engine, a battery pack is also installed on the chassis of the refrigerated truck, the first electric compressor and the second electric compressor are integrated on the front side of the refrigerated compartment, and the first evaporator, the second evaporator and the third evaporator are arranged around the interior space of the refrigerated compartment.

[0023] Based on the above, the battery pack includes an on-board low-voltage battery and a dedicated battery pack, the on-board low-voltage battery supplies power to the first heater, and the dedicated battery pack supplies power to the second heater, the first electric compressor and the second electric compressor.

[0024] Compared with the prior art, the present invention has outstanding substantial features and significant progress. Specifically, on the basis of the normal refrigeration unit, the present invention adds a set of ultra-low temperature auxiliary refrigeration unit and heat exchanger. In the ultra-low temperature working mode, the heat exchanger serves as the condenser of the ultra-low temperature auxiliary refrigeration unit and as the evaporator of the normal refrigeration unit. The cold energy generated by the normal refrigeration unit is used for the heat dissipation of the ultra-low temperature auxiliary refrigeration unit, so that the ultra-low temperature auxiliary refrigeration unit can produce a lower temperature, and then the refrigerated compartment is ultra-low temperature cooled through the second evaporator and the third evaporator, so as to reach a low temperature of -30°, realizing refrigeration in a wide range.

[0025] Furthermore, the compressors in the normal refrigeration unit include a road compressor and a first electric compressor, which can be driven by an engine or a battery to meet the driving requirements in different situations; and the second electric compressor is used in the ultra-low temperature auxiliary refrigeration unit, which is driven by a battery to meet the driving requirements of the entire refrigeration system.

[0026] Furthermore, setting two evaporators for the ultra-low temperature auxiliary refrigeration unit can maximize the refrigeration effect.

[0027] Furthermore, a liquid storage barrel is provided in the ultra-low temperature auxiliary refrigeration unit. When the ultra-low temperature auxiliary refrigeration unit is not in use, the refrigerant can be recovered into the liquid storage barrel to prevent the refrigerant from absorbing external heat.

[0028] Furthermore, for the liquid storage barrel, the normal refrigeration unit is also configured with a heat exchange pipeline, which cools the refrigerant in the liquid storage barrel through the normal refrigeration unit to prevent it from absorbing too much heat, so that the ultra-low temperature auxiliary refrigeration unit can take effect faster. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is an overall working principle diagram of the refrigeration unit of the present invention that can achieve the temperature requirements of a wide range in the refrigerated compartment.

[0030] Figure 2 This is a structural distribution diagram of a refrigeration unit in the present invention that can achieve wide-range temperature requirements in a refrigerated compartment.

[0031] Figure 3 This is a working principle diagram of the vehicle-mounted mode in Example 1 of the present invention.

[0032] Figure 4 It is a working principle diagram of the parking mode in embodiment 2 of the present invention.

[0033] Figure 5 This is a working principle diagram of the vehicle-mounted mode in Example 3 of the present invention.

[0034] Figure 6It is a working principle diagram of the parking mode in embodiment 4 of the present invention.

[0035] In the picture: 1. Refrigerated compartment; 2. Front condensing assembly; 3. Special battery pack; 4. Plate heat exchanger.

[0036] 11. Road compressor; 12. First electric compressor; 13. First one-way valve; 14. Second one-way valve; 15. First oil-gas separator; 16. First condenser; 17. First liquid storage tank; 18. Second stop valve; 19. Second thermal expansion valve; 20. First evaporator;

[0037] 21. First stop valve; 22. First thermal expansion valve; 23. First heater; 24. Second heater; 25. First gas-liquid separator;

[0038] 31. Second electric compressor; 32. Second oil-gas separator; 33. Fourth stop valve; 34. Third thermal expansion valve; 35. Fourth thermal expansion valve; 36. Second evaporator; 37. Third evaporator; 38. Second gas-liquid separator;

[0039] 41. Liquid storage tank; 42. Third stop valve; 43. Fifth stop valve; 44. Fifth thermal expansion valve; 45. Temperature sensor. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is further described in detail below through specific implementation methods.

[0041] In this embodiment, there are four working modes, namely, the vehicle mode and the parking mode in the normal temperature range, and the vehicle mode and the parking mode under ultra-low temperature requirements. The operation of the whole system is explained below through the respective descriptions of the four working modes.

[0042] like Figure 1 and Figure 2 As shown, a refrigeration unit that can meet the temperature requirements of a wide range in a refrigerated compartment includes a normal refrigeration unit, an ultra-low temperature auxiliary refrigeration unit and a heat exchanger. The heat exchanger is a plate heat exchanger. In other embodiments, a tube heat exchanger can also be used. The refrigerant in the normal refrigeration unit is R404a, and the refrigerant in the ultra-low temperature auxiliary refrigeration unit is R507a.

[0043] Among them, the electric compressor and related components in the normal refrigeration unit and the ultra-low temperature auxiliary refrigeration unit are integrated on the front side of the refrigerated compartment 1 as a front condensing assembly 2, and the road compressor 11 is installed on the engine side of the chassis for easy power extraction. The first evaporator 20, the second evaporator 36 and the third evaporator 37 are respectively installed in the refrigerated compartment 1. The first evaporator 20 cooperates with the normal refrigeration unit for heat absorption and heat release at conventional freezing temperatures, and the second evaporator 36 and the third evaporator 37 cooperate with the ultra-low temperature refrigeration unit to be responsible for heat absorption in the ultra-low temperature refrigerated compartment.

[0044] Example 1

[0045] like Figure 3 As shown in the figure, in vehicle-mounted mode, the process of conventional temperature freezing control for the refrigerated compartment is as follows:

[0046] The road compressor draws power from the engine, and the refrigerant R404a flows out from the exhaust port of the road compressor 11, passes through the first one-way valve 13, the first oil-gas separator 15, and the first condenser 16 to release heat into the air. The condensed liquid refrigerant passes through the first liquid reservoir 17, the second stop valve 18 and the second thermal expansion valve 19 and then flows into the first evaporator 20 to cool the interior of the refrigerated compartment. After absorbing the temperature in the compartment, the refrigerant returns to the road compressor 11 through the first gas-liquid separator, wherein the lubricating oil separated by the first oil-gas separator 15 flows back to the road compressor 11 through the pipeline.

[0047] When the temperature in the refrigerated compartment is low and needs to be heated, the vehicle-mounted low-voltage battery is used to power the first heater 23 to generate heat, and then the refrigerated compartment is heated through the fan circulation of the first evaporator 20 .

[0048] During this process, if the R507a refrigerant temperature sensor 45 in the liquid storage barrel 41 senses that the temperature exceeds 45°, the refrigerant flowing out of the first liquid storage tank 17 will pass through the fifth stop valve 43 and the fifth thermal expansion valve 44 to enter the heat exchange pipeline, cool the R507a refrigerant in the liquid storage barrel, and then merge with the refrigerant R404a flowing out of the first evaporator 20 and flow through the first gas-liquid separator 25 back to the intake port of the road compressor 11, realizing the circulation of the R404a refrigerant. When the temperature of the R507a refrigerant in the liquid storage barrel 41 is lower than 0 degrees, the fifth stop valve 43 is closed, and the refrigerant in the liquid storage barrel 41 is no longer cooled.

[0049] Example 2

[0050] like Figure 4 As shown in the figure, in parking mode, the process of conventional temperature freezing control for the refrigerated compartment is as follows:

[0051] Its working mode is the same as that of Example 1, except that the power source is changed from a road compressor to a first electric compressor 12, which is driven by electrical energy from a dedicated battery pack 3. The refrigerant R404a flows out of the first electric compressor 12, passes through the second one-way valve 14, and performs the same heat exchange process as in Example 1.

[0052] When heating is required, the second heat exchanger 24 is switched to operate, and the power comes from the dedicated battery pack 3, so as to avoid the vehicle being unable to start due to the low-voltage battery on board being low in power.

[0053] Example 3

[0054] like Figure 5 As shown in the figure, in vehicle-mounted mode, the control process for ultra-low temperature freezing (-30°C) or even lower temperature of the refrigerated compartment is as follows:

[0055] In the normal refrigeration unit, the refrigerant R404a flows out from the exhaust port of the road compressor 11, passes through the first oil-gas separator 15 to filter the refrigeration oil, and then passes through the first condenser 16 to dissipate heat. After passing through the first liquid storage tank 17, the outflowing refrigerant enters the first heat exchange path of the plate heat exchanger 4 through the first stop valve 21 and the first thermal expansion valve 22, exchanges heat with the refrigerant R507a in the ultra-low temperature auxiliary refrigeration unit in the plate heat exchanger 4, absorbs heat, and then returns to the road compressor 11 through the first gas-liquid separator 25;

[0056] The second electric compressor 31 in the ultra-low temperature auxiliary refrigeration unit is powered by a dedicated battery pack 3. The refrigerant R507a flows out from the exhaust port of the second electric compressor 31, filters the refrigeration oil through the second oil-gas separator 32, and releases heat to the R404a refrigerant in the normal refrigeration unit through the second heat exchange path of the plate heat exchanger 4. The condensed R507a refrigerant then passes through the fourth stop valve 33, flows to the third thermal expansion valve 34 and the fourth thermal expansion valve 35 respectively, and then enters the second evaporator 36 and the third evaporator 37 respectively, absorbs the heat in the refrigerated compartment 1 for cooling, and the outflowing refrigerant R507a is merged and flows through the second gas-liquid separator 38 back to the second electric compressor 31, wherein the refrigeration oil at the filtering point of the second oil-gas separator 32 flows back to the second electric compressor 31 through the pipeline.

[0057] Through the continuous cycle of heat absorption and heat dissipation of the normal refrigeration unit, the heat in the ultra-low temperature auxiliary refrigeration unit is dissipated to the outside at a lower temperature, maintaining the cold capacity in the ultra-low temperature auxiliary refrigeration unit, and then using the refrigerant and two evaporators to achieve ultra-low temperature refrigeration.

[0058] Example 4

[0059] like Figure 6 As shown in the figure, in parking mode, the process of ultra-low temperature freezing control of the refrigerated compartment is as follows:

[0060] Its working mode is the same as that of Example 1, the difference lies in the power source. The road compressor 11 in the normal refrigeration unit is replaced by the first electric compressor 12, which is driven by electric energy from the dedicated battery pack 3. The refrigerant R404a flows out from the first electric compressor 12, passes through the second one-way valve 14, and performs the same heat exchange process as Example 3.

[0061] The circulation system of refrigerant R507a remains unchanged.

[0062] Finally, whether in vehicle mode or parking mode, when the ultra-low temperature auxiliary refrigeration unit does not need to be operated and the second electric compressor 31 has not stopped running, the fourth stop valve 33 is closed and the third stop valve 42 is opened to uniformly recover the refrigerant R507a into the liquid storage barrel 41. Since the outer wall of the liquid storage barrel 41 is adhered with thermal insulation cotton, the refrigerant can reduce the heat absorbed by the outside world.

[0063] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A refrigeration unit capable of meeting the temperature requirements of a wide range in a refrigerated compartment, characterized in that: Including normal refrigeration unit, ultra-low temperature auxiliary refrigeration unit and heat exchanger; The normal refrigeration unit comprises a compressor, a first oil-gas separator, a condenser, a first stop valve, a second stop valve, a first thermal expansion valve, a second thermal expansion valve, a first evaporator, a first heater, a second heater, a first liquid reservoir and a first gas-liquid separator. The exhaust port of the compressor is sequentially connected to the first oil-gas separator, the condenser and the first liquid reservoir. The outlet of the first liquid reservoir is divided into two outputs: The first path is delivered to the first heat exchange path of the heat exchanger through the first stop valve and the first thermal expansion valve, and the loop of the first heat exchange path flows back to the compressor through the first gas-liquid separator; The second path is delivered to the first evaporator via the second stop valve and the second thermal expansion valve, and the circuit of the first evaporator flows back to the compressor via the first gas-liquid separator; The first heater and the second heater are both installed in the first evaporator; The ultra-low temperature auxiliary refrigeration unit includes a second electric compressor, a second oil-gas separator, a third thermal expansion valve, a fourth thermal expansion valve, a second evaporator, a third evaporator, a second gas-liquid separator and a fourth stop valve. The exhaust port of the second electric compressor passes through the second oil-gas separator, the second heat exchange passage of the heat exchanger and the fourth stop valve in sequence, and then is divided into two paths, which flow into the second evaporator through the third thermal expansion valve and into the third evaporator through the fourth thermal expansion valve respectively. The outlets of the second evaporator and the third evaporator merge and then flow into the inlet of the second gas-liquid separator. The outlet of the second gas-liquid separator flows back to the second electric compressor, and the oil return port of the second oil-gas separator flows back to the second electric compressor.

2. The refrigeration unit capable of achieving wide temperature range requirements in a refrigerated compartment according to claim 1, characterized in that: The heat exchanger is a plate heat exchanger or a tube heat exchanger.

3. The refrigeration unit capable of meeting the temperature requirements of a wide range in a refrigerated compartment according to claim 1 or 2, characterized in that: The refrigerant in the normal refrigeration unit is R404a, and the refrigerant in the ultra-low temperature auxiliary refrigeration unit is R507a.

4. The refrigeration unit capable of achieving wide temperature range requirements in a refrigerated compartment according to claim 3, characterized in that: The compressor includes a road compressor and a first electric compressor, which are arranged in parallel at the front end of the first oil-gas separator, and the road compressor and the first electric compressor are connected to the input end of the first oil-gas separator through a one-way valve respectively, and the oil return port of the oil-gas separator is connected to the first electric compressor and the road compressor respectively, and the outlet of the first gas-liquid separator is also connected to the first electric compressor and the road compressor respectively.

5. The refrigeration unit capable of achieving wide temperature range requirements in a refrigerated compartment according to claim 4, characterized in that: The ultra-low temperature auxiliary refrigeration unit also includes a liquid storage barrel and a third stop valve. The outlet end of the heat exchanger is connected to the inlet of the liquid storage barrel through the third stop valve and a pipeline. The outlet of the liquid storage barrel is connected to the inlet of the fourth stop valve. R507a refrigerant is stored in the liquid storage barrel, and an insulation layer is arranged on the outside of the liquid storage barrel.

6. The refrigeration unit capable of achieving wide temperature range requirements in a refrigerated compartment according to claim 5, characterized in that: A temperature sensor and a heat exchange pipeline are installed in the liquid storage barrel, the outlet end of the heat exchange pipeline is connected to the inlet end of the first gas-liquid separator, and the outlet end of the first liquid storage is connected to the inlet end of the heat exchange pipeline through the fifth stop valve and the thermal expansion valve; The temperature sensor is associated with the fifth stop valve, the second stop valve and the compressor of the normal refrigeration unit. When the temperature in the liquid storage barrel exceeds the set value, the compressor is controlled to be turned on, the second stop valve is closed, and the fifth stop valve is opened to cool the refrigerant in the liquid storage barrel through the heat exchange pipeline.

7. The refrigeration unit capable of achieving wide temperature range requirements in a refrigerated compartment according to any one of claims 4 to 6, characterized in that: The road compressor is installed on the chassis of the refrigerated truck near the engine. A battery pack is also installed on the chassis of the refrigerated truck. The first electric compressor and the second electric compressor are integrated on the front side of the refrigerated compartment. The first evaporator, the second evaporator and the third evaporator are arranged around the interior space of the refrigerated compartment.

8. The refrigeration unit capable of achieving wide temperature range requirements in a refrigerated compartment according to claim 7, characterized in that: The battery pack includes an on-board low-voltage battery and a dedicated battery pack. The on-board low-voltage battery supplies power to the first heater, and the dedicated battery pack supplies power to the second heater, the first electric compressor, and the second electric compressor.

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