A cold storage temperature control system based on refrigerant reflux

Abstract

The present invention belongs to the technical field of temperature control of cold storage, specifically a temperature control system of cold storage based on refrigerant reflux, including a compressor, the exhaust port of the compressor is connected to a condenser, an expansion valve, a slow freezing evaporator and a gas-liquid separator in sequence through a pipeline, the exhaust port of the gas-liquid separator is connected to the air inlet of the compressor through a pipeline; the expansion valve is also connected to the quick freezing evaporator through a pipeline, and the outlet of the quick freezing evaporator is connected to a liquid accumulator through a pipeline; the liquid accumulator includes a liquid storage tank, a liquid accumulation tank and a control box; a return liquid pipe is connected between the lower side of the liquid storage tank and the lower side of the liquid accumulation tank, and a liquid level check valve is arranged on the return liquid pipe; the upper end of the side of the liquid storage tank is connected to the upper end of the liquid accumulation tank through a pipeline; the device can not only avoid excessive liquid refrigerant from flowing back into the gas-liquid separator, but also improve the utilization rate of the liquid refrigerant, thereby reducing the energy consumption of the system by reusing the reflux refrigerant.

Description

Technical Field

[0001] The invention relates to the technical field of cold storage temperature control, and in particular to a cold storage temperature control system based on refrigerant reflux. Background Art

[0002] Cold storage refers to the use of artificial means to create an environment with different temperature or humidity from the outdoor environment. It is also a constant temperature and humidity storage equipment for food, liquids, chemicals, medicines, vaccines, scientific experiments, etc. Cold storage includes: fresh cold storage (its temperature is generally between 0℃ and 10℃), refrigerated cold storage (its temperature is generally between -18℃ and -5℃), frozen cold storage (its temperature is generally between -25℃ and -18℃) and ultra-low temperature cold storage (its temperature is generally between -80℃ and -60℃).

[0003] When the cold storage is refrigerated, the refrigerant is compressed into a high-temperature and high-pressure gas through a compressor and sent to the condenser; the refrigerant releases heat in the condenser and becomes a high-pressure liquid; then, the high-pressure liquid is reduced in pressure through an expansion valve and becomes a low-temperature and low-pressure wet steam that enters the evaporator, where it absorbs heat from the indoor air, lowering the air temperature while evaporating itself into a gas; finally, the gaseous refrigerant is sucked into the compressor again, starting a new round of circulation.

[0004] When the cold storage is refrigerating, the refrigeration efficiency is improved by controlling the flow rate of the refrigerant entering the evaporator; when the fresh-keeping cold storage is refrigerating (or the cold storage is refrigerating with slow temperature control), the flow rate of the refrigerant entering the evaporator is low. At this time, most of the liquid refrigerant evaporates into gas in the evaporator, and a small amount of liquid refrigerant will enter the gas-liquid separator with the gaseous refrigerant and complete evaporation in the gas-liquid separator. When the frozen cold storage and ultra-low temperature cold storage are refrigerating (or the refrigerated cold storage is in rapid temperature adjustment), the refrigerant flow rate entering the evaporator is relatively high. At this time, there will be a large amount of unevaporated liquid refrigerant in the evaporator, and the evaporated gaseous refrigerant enters the gas-liquid separator and evaporates slowly in the gas-liquid separator; in order to prevent the liquid refrigerant from entering the compressor, the gas-liquid separator needs to be equipped with a larger liquid storage tank so that the liquid refrigerant can be completely stored; a large amount of liquid refrigerant is concentrated in the gas-liquid separator for slow evaporation, which on the one hand reduces the energy utilization rate, thereby resulting in poor refrigeration effect of the cold storage; on the other hand, the liquid refrigerant is concentrated in the gas-liquid separator for evaporation, which will cause the temperature of the gaseous refrigerant entering the compressor to be too low, and when excessive low-temperature gaseous refrigerant enters the compressor, it will affect the normal operation of the compressor, and then affect the normal operation of the cold storage temperature control system. It is also possible to prevent liquid refrigerant from entering the compressor by discharging excess refrigerant in the gas-liquid separator. However, this method requires the recovery of the discharged liquid refrigerant, which functions like an external liquid storage device of the gas-liquid separator. Although it will not cause the temperature of the gas-liquid separator to be too low, it will still waste energy in the return refrigerant.

[0005] Therefore, we propose a cold storage temperature control system that reuses the reflux liquid refrigerant. Summary of the invention

[0006] The purpose of the present invention is to provide a cold storage temperature control system based on refrigerant reflux, so as to solve the problem of low energy utilization rate caused by large amount of liquid refrigerant reflux during rapid temperature control of the cold storage temperature control system proposed in the above background technology.

[0007] To achieve the above-mentioned object, the present invention provides the following technical solution: a cold storage temperature control system based on refrigerant reflux, comprising a compressor, the exhaust port of the compressor is sequentially connected to a condenser, an expansion valve, a slow freezing evaporator and a gas-liquid separator through a pipeline, the exhaust port of the gas-liquid separator is connected to the air inlet of the compressor through a pipeline; the expansion valve is also connected to a quick freezing evaporator through a pipeline, and the outlet of the quick freezing evaporator is connected to a liquid accumulator through a pipeline;

[0008] The liquid accumulator comprises a liquid storage tank, a liquid accumulation tank and a control box; a liquid return pipe is connected between the lower side of the liquid storage tank and the lower side of the liquid accumulation tank, and a liquid level one-way valve is arranged on the liquid return pipe; the upper end of the side of the liquid storage tank is connected to the upper end of the liquid accumulation tank through a pipeline; the liquid accumulation tank is installed on the upper side of the control box;

[0009] An exhaust column is arranged on the upper side of the control box, and an exhaust plug is movably arranged on the inner side of the exhaust column; a liquid discharge column is arranged on the lower side of the control box, and a liquid discharge plug is movably arranged on the inner side of the liquid discharge column; a hollow guide tube is arranged on the lower side of the liquid storage tank, and a load-bearing plug is arranged on the inner side of the hollow guide tube, and a load-bearing plate is arranged on the lower side of the load-bearing plug; a lever assembly for driving the load-bearing plate, the exhaust plug and the liquid discharge plug to slide up and down is arranged in the inner cavity of the control box;

[0010] The upper end of the liquid storage tank is connected to the exhaust column through a pipeline, and the lower end of the liquid storage tank is connected to the drain column through a pipeline;

[0011] The exhaust column of the liquid accumulator is connected to the gas-liquid separator through a pipe; the discharge column of the liquid accumulator is connected to the lateral evaporator through a pipeline, and the other end of the lateral evaporator is connected to the gas-liquid separator through a pipeline; the temperature of the cold storage where the lateral evaporator is located is higher than the temperature of the cold storage where the quick-freezing evaporator is located, and the position height of the lateral evaporator is lower than the position height of the quick-freezing evaporator;

[0012] The condenser comprises an outdoor condenser and an indoor condenser, and the outdoor condenser and the indoor condenser are connected in parallel; when the gaseous refrigerant passes through the condenser, it only passes through the outdoor condenser or the indoor condenser.

[0013] Preferably, the quick-freezing evaporator and the slow-freezing evaporator are respectively located on the top walls of the inner cavities of different cold storages; the indoor condenser and the lateral evaporator are both located on the side walls of the inner cavity of the cold storage, and the indoor condenser is located on the upper side of the lateral evaporator.

[0014] Preferably, the lever assembly includes a lever support installed on the lower wall of the inner cavity of the control box, and a supporting lever is movably installed on the upper side of the lever support; the left end of the supporting lever is hinged with a No. 1 connecting rod, and the right end of the supporting lever is hinged with a No. 2 connecting rod and a No. 3 connecting rod; the other end of the No. 2 connecting rod is hinged to the lower end of the exhaust plug; the other end of the No. 3 connecting rod is hinged to the upper end of the drain plug; the other end of the No. 1 connecting rod is hinged to the lower end of the load-bearing plate.

[0015] Preferably, the upper wall and the lower wall of the inner cavity of the control box are both provided with limit blocks, and the support lever is located between the upper and lower limit blocks.

[0016] Preferably, a return spring is provided on the outer side of the load-bearing plate, the upper side of the return spring is connected to the load-bearing plate, and the lower side of the return spring is connected to the outer wall of the control box.

[0017] Preferably, a spoiler is provided on the upper side of the inner cavity of the liquid accumulation tank, and the spoiler is located on the upper side of the load-bearing plug.

[0018] Preferably, a gas reversing valve is provided between the compressor and the condenser, and the gas inlet end and the gas outlet end of the gas reversing valve are connected to the compressor and the condenser respectively; the gas reversing valve is also connected to a gas-liquid heat exchanger through a pipeline, and the gas outlet end of the gas-liquid heat exchanger is connected to the condenser through a pipeline;

[0019] A liquid reversing valve is arranged between the liquid accumulator and the lateral evaporator, and the liquid inlet and liquid outlet of the liquid reversing valve are respectively connected to the liquid accumulator and the lateral evaporator; the gas reversing valve is also connected to the liquid inlet of the gas-liquid heat exchanger through a pipeline, and the liquid outlet of the gas-liquid heat exchanger is connected to the gas-liquid separator through a pipe.

[0020] Preferably, the gas reversing valve and the liquid reversing valve are driven by the same type of power, and when performing a switching operation, the gas reversing valve and the liquid reversing valve switch directions synchronously.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] 1) This device collects the reflux liquid refrigerant flowing through the quick freezing evaporator through a liquid storage tank. When other cold storages with higher temperatures need to be cooled, the reflux liquid refrigerant from the quick freezing evaporator is introduced into the lateral evaporator in the cold storage with higher temperatures. The reflux liquid refrigerant evaporates and absorbs heat in the lateral evaporator. By reusing the reflux refrigerant, not only can excessive liquid refrigerant be prevented from flowing back into the gas-liquid separator, but the utilization rate of the liquid refrigerant can also be improved, thereby reducing the energy consumption of the system.

[0023] 2) This device uses a liquid storage tank to perform preliminary separation of the gaseous refrigerant and the liquid refrigerant discharged from the quick freezing evaporator; then the gaseous refrigerant in the liquid storage tank is controlled to be discharged by moving the exhaust plug up and down in the exhaust column; the liquid refrigerant in the liquid storage tank is controlled to be discharged by moving the drain plug up and down in the drain column; when discharging the gaseous refrigerant, the liquid refrigerant is intercepted, so that a certain amount of liquid refrigerant can be stored in the liquid storage tank, and then there is sufficient liquid refrigerant to evaporate and absorb heat in the lateral evaporator; when the liquid refrigerant needs to be discharged, the gaseous refrigerant is intercepted, so that the gaseous refrigerant is pushed to be discharged by the gas pressure generated by the gaseous refrigerant;

[0024] 3) This device uses the gravity of liquid refrigerant to push the lever assembly. Since the density of liquid refrigerant is low, its buoyancy is small, and traditional buoyancy control is difficult to effectively control. However, this device uses the gravity of liquid refrigerant to push, and the amount of liquid refrigerant can be increased according to the force requirements, so that it has enough gravity to push the lever assembly to rotate.

[0025] 4) This device divides the condenser into an outdoor condenser and an indoor condenser. When the temperature inside the cold storage needs to be raised, the high-temperature and high-pressure liquid (refrigerant) is introduced into the indoor condenser so that the refrigerant can dissipate heat inside the cold storage, thereby raising the temperature inside the cold storage while lowering the refrigerant temperature (the refrigerant temperature is slightly lower than that of the outdoor condenser), thereby reducing the amount of refrigerant under the same cooling conditions, thereby reducing the compressor cycle frequency and reducing system energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the pipe connection of the temperature control system of the present invention;

[0027] Figure 2 This is a schematic diagram of the refrigerant circulation during the slow temperature adjustment of the present invention;

[0028] Figure 3 This is a schematic diagram of the circulation structure of the refrigerant evaporated through the heat exchanger during the rapid temperature adjustment of the present invention;

[0029] Figure 4 This is a schematic diagram of the refrigerant circulation through the lateral evaporator during rapid temperature adjustment of the present invention;

[0030] Figure 5 It is a schematic diagram of the structure of the liquid accumulator of the present invention;

[0031] Figure 6 It is a schematic diagram of the cross-sectional structure of the liquid storage tank and the control box of the present invention;

[0032] Figure 7 The diagram is a schematic diagram of the layout of the slow freezing evaporator, outdoor condenser and indoor condenser in a cold storage according to the present invention.

[0033] In the figure: 1 compressor, 2 gas-liquid separator, 3 gas reversing valve, 4 gas-liquid heat exchanger, 5 condenser, 6 expansion valve, 7 quick-freezing evaporator, 8 slow-freezing evaporator, 9 liquid accumulator, 10 liquid reversing valve, 11 lateral evaporator;

[0034] 51 outdoor condenser, 52 indoor condenser;

[0035] 91 liquid storage tank, 92 liquid level one-way valve, 93 liquid accumulation tank, 94 control box;

[0036] 931 spoiler, 932 hollow guide tube, 933 load-bearing plug, 934 load-bearing plate, 935 return spring;

[0037] 941 exhaust column, 942 exhaust plug, 943 drain column, 944 drain plug;

[0038] 951 lever support, 952 supporting lever, 953 connecting rod No. 1, 954 connecting rod No. 2, 955 connecting rod No. 3, 956 limiting block. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. Example

[0041] See also Figure 1-7The present invention provides a technical solution: a cold storage temperature control system based on refrigerant reflux, comprising a compressor 1, the exhaust port of the compressor 1 is connected to a condenser 5, an expansion valve 6, a slow freezing evaporator 8 and a gas-liquid separator 2 in sequence through a pipeline, and the exhaust port of the gas-liquid separator 2 is connected to the air inlet of the compressor 1 through a pipeline; the connection between the compressor 1, the condenser 5, the expansion valve 6, the slow freezing evaporator 8 and the gas-liquid separator 2 adopts the existing technology, wherein the temperature sensor, humidity controller, compressor load sensor and other cold storage temperature control system monitoring and temperature control devices required for the temperature control system all adopt commonly used electronic components in the existing technology (not shown in the figure). When the fresh-keeping cold storage is refrigerating (or the refrigerated cold storage is refrigerating with slow temperature control), the cold storage temperature control system in the prior art can be used normally, that is, the compressor 1 compresses the gaseous refrigerant into high-temperature and high-pressure gas, and sends the high-temperature and high-pressure gas into the condenser 5 to release heat and become a high-pressure liquid, and then the high-pressure liquid is reduced in pressure through the expansion valve 6 and flows into the slow freezing evaporator 8, and the high-pressure liquid evaporates and absorbs heat in the slow freezing evaporator 8, and part of the high-pressure liquid will evaporate into gas (that is, the refrigerant in the slow freezing evaporator 8 at this time has both gaseous refrigerant and liquid refrigerant, among which the gaseous refrigerant is more and the liquid refrigerant is less), and then the refrigerant in the slow freezing evaporator 8 enters the gas-liquid separator 2, and the gas-liquid separation is carried out in the gas-liquid separator 2, and then the gaseous refrigerant enters the compressor 1 again. Among them, in order to prevent the refrigerant from flowing back into the slow freezing evaporator 8, a one-way valve is provided at the outlet of the slow freezing evaporator 8.

[0042] When the freezing cold storage and the ultra-low temperature cold storage are refrigerating (or the refrigerated cold storage is rapidly adjusting the temperature), a large amount of liquid refrigerant cannot be completely evaporated in one evaporator, so it is necessary to divide the liquid refrigerant into two evaporators to adjust the temperature of different cold storages respectively. The expansion valve 6 is also connected to the quick freezing evaporator 7 through a pipeline, and multiple expansion valves 6 can be set, and the quick freezing evaporator 7 and the slow freezing evaporator 8 are respectively connected to an expansion valve 6. The quick freezing evaporator 7 and the slow freezing evaporator 8 are arranged in different cold storages, and the slow freezing evaporator 8 corresponds to the fresh cold storage or the refrigerated cold storage with slow temperature adjustment refrigeration; the quick freezing evaporator 7 corresponds to the freezing cold storage, the ultra-low temperature cold storage or the refrigerated cold storage with rapid temperature adjustment refrigeration; when the fresh cold storage or the refrigerated cold storage with slow temperature adjustment refrigeration is refrigerated, the liquid refrigerant enters the slow freezing evaporator 8 through the expansion valve 6; when the freezing cold storage, the ultra-low temperature cold storage or the refrigerated cold storage with rapid temperature adjustment refrigeration is refrigerated, the liquid refrigerant enters the quick freezing evaporator 7 through the expansion valve 6. The outlet of the quick-freezing evaporator 7 is connected to a liquid accumulator 9 through a pipeline. When the reflux refrigerant is reused for a second time, a certain amount of refrigerant is required. Here, the unevaporated refrigerant in the quick-freezing evaporator 7 is collected by the liquid accumulator 9.

[0043] The liquid accumulator 9 includes a liquid storage tank 91, a liquid storage tank 93 and a control box 94; the liquid storage tank 91 is used to collect the unevaporated refrigerant in the freezing evaporator 7, so a pipeline is set on the outside of the liquid storage tank 91 to connect with the outlet of the freezing evaporator 7. The liquid storage tank 93 is used to detect whether the amount of liquid refrigerant stored in the liquid storage tank 91 reaches the discharge standard; the upper end of the side of the liquid storage tank 91 is connected to the upper end of the liquid storage tank 93 through a pipeline. As the amount of liquid refrigerant in the liquid storage tank 91 increases, the liquid level of the liquid refrigerant in the liquid storage tank 91 will also increase. When the amount of liquid refrigerant in the liquid storage tank 91 reaches the discharge standard, the liquid refrigerant begins to enter the liquid storage tank 93 from the upper side of the liquid storage tank 93 through the pipeline. When discharging the liquid refrigerant in the liquid storage tank 91, it is necessary to ensure that the liquid level of the liquid refrigerant in the liquid storage tank 91 begins to cover the liquid refrigerant discharge outlet of the liquid storage tank 91, that is, to prevent the liquid refrigerant in the liquid storage tank 91 from being completely discharged. Similarly, the liquid level of the liquid storage tank 91 is detected by the liquid storage tank 93. A return pipe is connected between the lower side of the liquid storage tank 91 and the lower side of the liquid storage tank 93. The liquid refrigerant in the liquid storage tank 93 can be discharged into the liquid storage tank 91 through the return pipe. When the liquid storage tank 93 is discharged to a certain amount, it means that the liquid refrigerant in the liquid storage tank 91 can stop being discharged. In order to prevent the liquid refrigerant in the liquid storage tank 91 from entering the liquid storage tank 93 through the return pipe, a liquid level check valve 92 can be set on the return pipe to prevent the liquid refrigerant in the liquid storage tank 91 from entering the liquid storage tank 93 along the return pipe. The load-bearing plug 933 can also be used to block the pipe opening at the connection between the return pipe and the liquid storage tank 93 to prevent the liquid refrigerant in the liquid storage tank 91 from entering the liquid storage tank 93 through the return pipe. The control box 94 is used to control the discharge and retention of the liquid refrigerant and the gaseous refrigerant in the liquid storage tank 91. The liquid storage tank 93 is installed on the upper side of the control box 94 and is used to transmit the detection signal to the control box 94.

[0044] An exhaust column 941 is provided on the upper side of the control box 94, and an exhaust plug 942 is movably provided on the inner side of the exhaust column 941; an air guide hole is provided through the side of the exhaust column 941, one end of the air guide hole is connected to the upper end of the liquid storage tank 91 through a pipeline, and the other end of the air guide hole is connected to the gas-liquid separator 2 through a pipeline. In order to prevent the refrigerant from flowing back to the exhaust column 941, a one-way valve is also provided between the air guide hole and the gas-liquid separator 2. An air vent is also provided through the outer side of the exhaust plug 942. When the air vent and the air guide are aligned, the gaseous refrigerant in the liquid storage tank 91 can be discharged normally; after the exhaust plug 942 is moved up, the air vent and the air guide are misaligned, and the gaseous refrigerant in the liquid storage tank 91 is difficult to discharge. A drain column 943 is provided at the lower side of the control box 94, and a drain hole is provided on the outer side of the drain column 943, one end of the drain hole is connected to the lower end of the liquid storage tank 91 through a pipeline, and the other end of the drain hole is connected to the lateral evaporator 11 through a pipeline. A guide hole is provided on the outer side of the drain column 943, and when the guide hole and the drain hole are misaligned, the liquid refrigerant in the liquid storage tank 91 is difficult to discharge; when the drain column 943 moves upward, the guide hole is aligned with the drain hole, and the liquid refrigerant in the liquid storage tank 91 can be discharged normally. A hollow guide tube 932 is provided at the lower side of the liquid accumulating tank 93, and a bearing plug 933 is provided at the inner side of the hollow guide tube 932. The bearing plug 933 is configured as a piston, which is sealed with the hollow guide tube 932. After a sufficient amount of liquid refrigerant is poured into the liquid accumulating tank 93, the liquid refrigerant pushes the bearing plug 933 downward by gravity, and a bearing plate 934 is provided at the lower side of the bearing plug 933, and the bearing plate 934 is synchronously raised and lowered with the bearing plug 933. A lever assembly is provided in the inner cavity of the control box 94, and the lever assembly is used to drive the bearing plate 934, the exhaust plug 942 and the drain plug 944 to slide up and down. The bearing plate 934 transmits a downward movement signal, and the lever assembly moves downward at one end, driving the other end to move upward, thereby driving the exhaust plug 942 and the drain plug 944 to move upward, thereby controlling the gaseous refrigerant to stop discharging and controlling the liquid refrigerant to discharge.

[0045] The other end of the lateral evaporator 11 is connected to the gas-liquid separator 2 through a pipeline. In order to prevent the refrigerant from flowing back into the lateral evaporator 11, a one-way valve is also provided between the lateral evaporator 11 and the gas-liquid separator 2. The temperature of the cold storage where the lateral evaporator 11 is located is higher than the temperature of the cold storage where the quick freezing evaporator 7 is located. For example, the quick freezing evaporator 7 is used for a freezing cold storage at -25°C to -18°C, then the lateral evaporator 11 can only be used for a refrigeration cold storage at -18°C to -5°C or a fresh-keeping cold storage at 0°C to 10°C; after passing through the expansion valve 6, part of the liquid refrigerant will evaporate and absorb heat in the quick freezing evaporator 7, and the remaining unevaporated liquid refrigerant can still evaporate and absorb heat in other evaporators, so it should be put into a high-temperature cold storage for use, thereby cooling the high-temperature cold storage. Since the liquid refrigerant after passing through the quick-freezing evaporator 7 has insufficient power, the present device is provided with two methods to prompt the liquid refrigerant passing through the quick-freezing evaporator 7 to enter the side evaporator 11; one is to seal the discharge of the gaseous refrigerant in the liquid storage tank 91, increase the air pressure in the liquid storage tank 91, and press the liquid refrigerant into the side evaporator 11 through the air pressure; the other is to make the position height of the side evaporator 11 lower than the position height of the quick-freezing evaporator 7 during installation, so that the liquid refrigerant can automatically flow into the side evaporator 11 under the action of gravity.

[0046] When heating up the cold storage, the prior art is to increase the temperature inside the cold storage by ventilating the cold storage; this method will also lead to energy waste. The condenser 5 includes two types: an outdoor condenser 51 and an indoor condenser 52; the outdoor condenser 51 is installed outside the cold storage, and the indoor condenser 52 is installed inside the cold storage; the outdoor condenser 51 and the indoor condenser 52 are connected in parallel, that is, other refrigerants entering the condenser 5 are diverted by a diverter or a tee (not shown in the figure), and the outdoor condenser 51 and the indoor condenser 52 are both connected to the diverter (or tee) through a pipeline, and a valve is provided on the pipeline; through the valve control, it is selected whether the refrigerant in the diverter (or tee) enters the outdoor condenser 51 or the indoor condenser 52, and when the refrigerant passes through the outdoor condenser 51, it is prohibited to enter the indoor condenser 52; when the refrigerant passes through the indoor condenser 52, it is prohibited to enter the outdoor condenser 51. When it is necessary to heat up the cold storage, the refrigerant is controlled to enter the indoor condenser 52.

[0047] When installing the quick-freezing evaporator 7, the slow-freezing evaporator 8, the lateral evaporator 11 and the indoor condenser 52; the quick-freezing evaporator 7 and the slow-freezing evaporator 8 are both located on the top wall of the inner cavity of the cold storage, and the indoor condenser 52 and the lateral evaporator 11 are both located on the side wall of the inner cavity of the cold storage; so that the height of the quick-freezing evaporator 7 is higher than the height of the lateral evaporator 11. During installation, the quick-freezing evaporator 7, the lateral evaporator 11 and the indoor condenser 52 can be installed in one cold storage, and only the quick-freezing evaporators 7 and the lateral evaporators 11 in different cold storages are connected, and the quick-freezing evaporator 7 and the lateral evaporator 11 in the same cold storage are not connected; the slow-freezing evaporator 8, the lateral evaporator 11 and the indoor condenser 52 can be installed in one cold storage. In the cold storage, the indoor condenser 52 is located on the upper side of the lateral evaporator 11, thereby further increasing the height difference between the lateral evaporator 11 and the quick-freezing evaporator 7.

[0048] The lever assembly includes a lever support 951 installed on the lower wall of the inner cavity of the control box 94, and a support lever 952 is movably installed on the upper side of the lever support 951. The support point of the support lever 952 is located to the right of its midpoint, so that the force arm corresponding to the load-bearing plate 934 has a larger length, thereby facilitating the load-bearing plate 934 to push the support lever 952 to rotate. The left end of the support lever 952 is hinged with a No. 1 connecting rod 953, and the right end of the support lever 952 is hinged with a No. 2 connecting rod 954 and a No. 3 connecting rod 955; the other end of the No. 2 connecting rod 954 is hinged to the lower end of the exhaust plug 942; the other end of the No. 3 connecting rod 955 is hinged to the upper end of the drain plug 944; the No. 2 connecting rod 954 and the No. 3 connecting rod 955 are both hinged to the right end of the support lever 952, so that when the support lever 952 rotates, it will drive the exhaust plug 942 and the drain plug 944 to move synchronously, so that the exhaust plug 942 and the drain plug 944 will move up and down synchronously, and after the liquid refrigerant in the liquid accumulation tank 93 flows out, the exhaust plug 942 and the drain plug 944 will drive the right end of the support lever 952 to move downward under the action of gravity, thereby driving the support lever 952 to reset. The other end of the No. 1 connecting rod 953 is hinged to the lower end of the bearing plate 934 .

[0049] Limit blocks 956 are provided on the upper and lower walls of the inner cavity of the control box 94, and the support lever 952 is located between the upper and lower limit blocks 956; the limit blocks 956 are used to limit the rotation angle of the support lever 952, thereby limiting the up and down movement distance of the load-bearing plate 934, the exhaust plug 942 and the drain plug 944.

[0050] A return spring 935 is arranged on the outer side of the load-bearing plate 934. The upper side of the return spring 935 is connected to the load-bearing plate 934, and the lower side of the return spring 935 is connected to the outer wall of the control box 94. The load-bearing plate 934 is made of metal, and the metal plate is not easy to deform. The return spring 935 can push the load-bearing plate 934 to move up and return to its original position through elastic force, and then push the load-bearing plug 933 to move up through the load-bearing plate 934; the load-bearing plate 934 is pushed up by the return spring 935, and the load-bearing plate 934 will drive the support lever 952 to reset, further increasing the torsion force on the support lever 952 when it is reset, so as to facilitate the automatic reset of the support lever 952.

[0051] In order to prevent the impact force of the liquid refrigerant entering the liquid storage tank 93, causing the load-bearing plug 933 to move downward; a spoiler 931 is provided on the upper side of the inner cavity of the liquid storage tank 93, and the spoiler 931 is located on the upper side of the load-bearing plug 933; after the liquid refrigerant enters the liquid storage tank 93, it will impact the spoiler 931, and through the interference of the spoiler 931, the liquid refrigerant will flow down from the non-center side of the inner cavity of the liquid storage tank 93, thereby preventing the liquid refrigerant from directly impacting the load-bearing plug 933.

[0052] The refrigerant is reused by introducing the refluxed liquid refrigerant into the lateral evaporator 11. However, this method can only be used when the cold storage where the lateral evaporator 11 is located needs to be cooled. When the cold storage where the lateral evaporator 11 is located does not need to be cooled, other methods are required to heat the refluxed liquid refrigerant. An air reversing valve 3 is provided between the compressor 1 and the condenser 5. The air inlet end of the air reversing valve 3 is connected to the air outlet end of the compressor 1 through a pipeline. One air outlet end of the air reversing valve 3 is connected to the condenser 5 through a pipeline. The other air outlet end of the air reversing valve 3 is connected to the air inlet end of the gas-liquid heat exchanger 4 through a pipeline. The air outlet end of the gas-liquid heat exchanger 4 is connected to the condenser 5 through a pipeline. In order to prevent the airflow from flowing back, a one-way valve is also provided between the air outlet end of the gas-liquid heat exchanger 4 and the condenser 5. A liquid reversing valve 10 is provided between the liquid accumulator 9 and the lateral evaporator 11, the inlet of the liquid reversing valve 10 is connected to the drainage column 943 of the liquid accumulator 9 through a pipeline, one outlet of the liquid reversing valve 10 is connected to the lateral evaporator 11, and the other outlet of the liquid reversing valve 10 is connected to the liquid inlet of the gas-liquid heat exchanger 4; the liquid outlet of the gas-liquid heat exchanger 4 is connected to the gas-liquid separator 2 through a pipeline, and in order to prevent the refrigerant from flowing back to the gas-liquid heat exchanger 4, a one-way valve is also provided on the pipeline. When the lateral evaporator 11 does not need liquid refrigerant; by adjusting the gas reversing valve 3 and the liquid reversing valve 10, the gaseous refrigerant enters the gas-liquid heat exchanger 4 first; at the same time, the liquid refrigerant discharged from the accumulator 9 will also enter the gas-liquid heat exchanger 4; the liquid refrigerant and the gaseous refrigerant exchange heat in the gas-liquid heat exchanger 4, the liquid refrigerant evaporates and takes away the heat, and the temperature of the gaseous refrigerant decreases and becomes liquid (since the gaseous refrigerant releases more heat, its temperature will also be lower). When lowering the same temperature, the lower the refrigerant temperature, the lower its usage; therefore, when the refrigerant temperature is low, the amount of refrigerant passing through the expansion valve 6 will also be reduced accordingly, and then the operating frequency of the compressor 1 can be reduced, thereby achieving the purpose of energy saving, which can be adjusted by opening and closing the expansion valve 6 (the opening and closing control of the expansion valve 6 belongs to the prior art and will not be repeated here).

[0053] The gas reversing valve 3 and the liquid reversing valve 10 are driven by the same type of power, such as both are pneumatic or both are electric; during switching operations, the reversing valves driven by the same power can perform synchronous direction switching, thereby facilitating simultaneous changes in the flow direction of the refrigerant in the gas reversing valve 3 and the liquid reversing valve 10.

[0054] This device is designed based on the outdoor temperature being higher than the indoor temperature of the cold storage. Some valves commonly used in the cold storage temperature control system, such as the four-way reversing valve, solenoid valve, safety valve, etc., are not drawn in the figure. Technical personnel in this field can add these common valves as needed during installation.

[0055] Working principle: When the cold storage needs to be heated up, first, the valves corresponding to both ends of the outdoor condenser 51 are closed by opening and closing the valves, and the valves corresponding to both ends of the indoor condenser 52 in the cold storage that needs to be heated up are opened. When the compressor 1 is working, the gas refrigerant is compressed into high-temperature and high-pressure gas, and then the high-temperature and high-pressure gas flows into the indoor condenser 52 through the gas reversing valve 3, and the high-temperature and high-pressure gas dissipates heat in the indoor condenser 52, thereby driving the temperature in the cold storage to rise; since the temperature in the cold storage is lower than the outdoor temperature, the temperature of the high-temperature and high-pressure gas will be lower than that of the outdoor temperature when it is cooled down; the high-temperature and high-pressure gas will become a high-pressure liquid after cooling down, and the high-pressure liquid will evaporate and absorb heat in the evaporator after the pressure is reduced by the expansion valve 6, and then the refrigerant in the evaporator will flow back to the gas-liquid separator 2, and the gas pressure separation will be carried out in the gas-liquid separator 2, and finally the gaseous refrigerant will flow back to the compressor 1 for the next cycle. When the refrigerant enters the evaporator, the opening and closing of the expansion valve 6 can be used to control the refrigerant to enter the quick freezing evaporator 7 or the slow freezing evaporator 8.

[0056] When there are two cold storages with temperature difference that need to be cooled, and the cold storage with lower temperature is in quick-freezing evaporator 7; first, the refrigerant enters quick-freezing evaporator 7, and then the liquid refrigerant evaporates in quick-freezing evaporator 7, but some liquid refrigerant does not evaporate in time, and enters into liquid storage tank 91 of liquid accumulator 9 together with the evaporated gaseous refrigerant; in liquid storage tank 91, the gaseous refrigerant floats up and is discharged into gas-liquid separator 2 along exhaust column 94 through pipeline, and the liquid refrigerant therein is deposited at the bottom of liquid storage tank 91, and as the liquid level of the liquid refrigerant in liquid storage tank 91 rises, the liquid refrigerant will eventually flow into liquid accumulator 93 along the pipeline, and as the weight of the liquid refrigerant in liquid accumulator 93 increases, the liquid refrigerant will be discharged under the influence of gravity. Under the action of , the load-bearing plug 933 will be pressed downward, and the load-bearing plug 933 will move the load-bearing plate 934 downward. The load-bearing plate 934 will drive the support lever 952 to rotate through the No. 1 connecting rod 953, and the support lever 952 will drive the exhaust plug 942 to move upward through the No. 2 connecting rod 954. The exhaust plug 942 moves upward to cut off the air guide hole of the exhaust column 941, and the air pressure in the liquid storage tank 91 gradually increases; when the support lever 952 rotates, it will also drive the drain plug 944 to move upward, and the drain plug 944 moves upward to connect the guide hole of the drain column 943, and the liquid refrigerant in the liquid storage tank 91 begins to be discharged into the side evaporator 11, and continues to evaporate and absorb heat in the side evaporator 11; finally, the refrigerant in the side evaporator 11 is discharged into the gas-liquid separator 2. When the liquid level of the liquid refrigerant in the liquid storage tank 91 drops to the same level as the liquid level of the liquid refrigerant in the liquid accumulation tank 93, the liquid refrigerant in the liquid accumulation tank 93 flows into the liquid storage tank 91 through the liquid level one-way valve 92, and drops synchronously with the liquid level of the liquid refrigerant in the liquid storage tank 91. As the liquid refrigerant in the liquid accumulation tank 93 gradually decreases, when the weight of the liquid refrigerant in the liquid accumulation tank 93 is not enough to suppress the load-bearing plug 933, the dead weight of the exhaust plug 942 and the drain plug 944 and the elastic force of the return spring 935 will drive the support lever 952 to rotate in the opposite direction. At this time, the exhaust plug 942 moves downward, and the air guide hole of the exhaust column 941 is reconnected, so that the gaseous refrigerant in the liquid storage tank 91 can be discharged normally; the drain plug 944 moves downward, cutting off the guide hole of the drain column 943, and the liquid refrigerant in the liquid storage tank 91 cannot be discharged normally.

[0057] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention; therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is limited by the attached claims rather than the above description. Therefore, it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the present invention, and any figure marks in the claims should not be regarded as limiting the claims involved.

[0058] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cold storage temperature control system based on refrigerant reflux, comprising a compressor (1), wherein the exhaust port of the compressor (1) is sequentially connected to a condenser (5), an expansion valve (6), a slow freezing evaporator (8) and a gas-liquid separator (2) via a pipeline, and the exhaust port of the gas-liquid separator (2) is connected to the air inlet of the compressor (1) via a pipeline; characterized in that: The expansion valve (6) is also connected to a quick-freezing evaporator (7) via a pipeline, and the outlet of the quick-freezing evaporator (7) is connected to a liquid accumulator (9) via a pipeline; The liquid accumulator (9) comprises a liquid storage tank (91), a liquid accumulation tank (93) and a control box (94); a liquid return pipe is connected between the lower side of the liquid storage tank (91) and the lower side of the liquid accumulation tank (93), and a liquid level check valve (92) is provided on the liquid return pipe; the upper end of the side surface of the liquid storage tank (91) is connected to the upper end of the liquid accumulation tank (93) through a pipeline; the liquid accumulation tank (93) is installed on the upper side of the control box (94); An exhaust column (941) is provided on the upper side of the control box (94), and an exhaust plug (942) is movably provided on the inner side of the exhaust column (941); a liquid discharge column (943) is provided on the lower side of the control box (94), and a liquid discharge plug (944) is movably provided on the inner side of the liquid discharge column (943); a hollow guide tube (932) is provided on the lower side of the liquid accumulation tank (93), a load-bearing plug (933) is provided on the inner side of the hollow guide tube (932), and a load-bearing plate (934) is provided on the lower side of the load-bearing plug (933); a lever assembly for driving the load-bearing plate (934), the exhaust plug (942) and the liquid discharge plug (944) to slide up and down is provided in the inner cavity of the control box (94); The upper end of the liquid storage tank (91) is connected to the exhaust column (941) via a pipeline, and the lower end of the liquid storage tank (91) is connected to the drain column (943) via a pipeline; The exhaust column (941) of the liquid accumulator (9) is connected to the gas-liquid separator (2) via a pipe; the discharge column (943) of the liquid accumulator (9) is connected to the lateral evaporator (11) via a pipe, and the other end of the lateral evaporator (11) is connected to the gas-liquid separator (2) via a pipe; the temperature of the cold storage where the lateral evaporator (11) is located is higher than the temperature of the cold storage where the quick-freezing evaporator (7) is located, and the height of the lateral evaporator (11) is lower than the height of the quick-freezing evaporator (7); The condenser (5) comprises an outdoor condenser (51) and an indoor condenser (52), and the outdoor condenser (51) and the indoor condenser (52) are connected in parallel; when the gaseous refrigerant passes through the condenser (5), it only passes through the outdoor condenser (51) or the indoor condenser (52).

2. According to claim 1, a cold storage temperature control system based on refrigerant reflux is characterized in that: The quick freezing evaporator (7) and the slow freezing evaporator (8) are respectively located on the top walls of the inner cavities of different cold storages; the indoor condenser (52) and the lateral evaporator (11) are both located on the side walls of the inner cavity of the cold storage, and the indoor condenser (52) is located on the upper side of the lateral evaporator (11).

3. According to claim 1, a cold storage temperature control system based on refrigerant reflux is characterized in that: The lever assembly comprises a lever support (951) mounted on the lower wall of the inner cavity of the control box (94); a support lever (952) is movably mounted on the upper side of the lever support (951); a No. 1 connecting rod (953) is hingedly connected to the left end of the support lever (952); a No. 2 connecting rod (954) and a No. 3 connecting rod (955) are hingedly connected to the right end of the support lever (952); the other end of the No. 2 connecting rod (954) is hingedly connected to the lower end of the exhaust plug (942); the other end of the No. 3 connecting rod (955) is hingedly connected to the upper end of the drain plug (944); and the other end of the No. 1 connecting rod (953) is hingedly connected to the lower end of the load-bearing plate (934).

4. A cold storage temperature control system based on refrigerant reflux according to claim 3, characterized in that: Limit blocks (956) are provided on both the upper wall and the lower wall of the inner cavity of the control box (94), and the support lever (952) is located between the upper and lower limit blocks (956).

5. According to claim 1, a cold storage temperature control system based on refrigerant reflux is characterized in that: A return spring (935) is arranged on the outer side of the load-bearing plate (934); the upper side of the return spring (935) is connected to the load-bearing plate (934), and the lower side of the return spring (935) is connected to the outer wall of the control box (94).

6. A cold storage temperature control system based on refrigerant reflux according to claim 1, characterized in that: A spoiler (931) is provided on the upper side of the inner cavity of the liquid accumulation tank (93), and the spoiler (931) is located on the upper side of the load-bearing plug (933).

7. A cold storage temperature control system based on refrigerant reflux according to claim 1, characterized in that: An air reversing valve (3) is provided between the compressor (1) and the condenser (5), and the air inlet end and the air outlet end of the air reversing valve (3) are respectively connected to the compressor (1) and the condenser (5); the air reversing valve (3) is also connected to an air-liquid heat exchanger (4) via a pipeline, and the air outlet end of the air-liquid heat exchanger (4) is connected to the condenser (5) via a pipeline; A liquid reversing valve (10) is provided between the liquid accumulator (9) and the lateral evaporator (11); the liquid inlet end and the liquid outlet end of the liquid reversing valve (10) are respectively connected to the liquid accumulator (9) and the lateral evaporator (11); the gas reversing valve (3) is also connected to the liquid inlet end of the gas-liquid heat exchanger (4) via a pipeline, and the liquid outlet end of the gas-liquid heat exchanger (4) is connected to the gas-liquid separator (2) via a pipe.

8. A cold storage temperature control system based on refrigerant reflux according to claim 7, characterized in that: The gas reversing valve (3) and the liquid reversing valve (10) are driven by the same type of power, and when performing a switching operation, the gas reversing valve (3) and the liquid reversing valve (10) switch directions synchronously.

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