A frost-free freezing and refrigerating storage system

Abstract

The present invention discloses a frost-free freezing cold storage system, including an antifreeze spray heat exchanger arranged in the cold storage and a refrigeration unit arranged outside the cold storage, the refrigeration unit including a cooling tower, a cooling circulation pump connected to the cooling tower at one end, the other end of the cooling circulation pump connected to the refrigeration unit condenser, and also including a refrigeration unit evaporator, a refrigeration unit compressor and a refrigeration unit throttling device, one end of the refrigeration unit evaporator is connected to the antifreeze spray heat exchanger through a refrigerant circulation pump, and the refrigerant in the refrigerant overflow tank is sucked into the refrigeration unit evaporator to release latent heat and be cooled, thereby completing the open circulation of the system refrigerant. The present invention saves more than 30% energy than the existing water-cooled cold storage, and is more energy-efficient than the air-cooled cold storage, there is no loss of antifreeze (refrigerant), and there is no loss of defrosting brine, water consumption is very small, and it has a strong environmental advantage.

Description

Technical Field

[0001] The present invention relates to refrigeration machinery, in particular to the technical field of cold storage refrigeration machinery, and specifically to a frost-free freezing and refrigerating storage system. Background Art

[0002] The operating cost of cold storage is mainly composed of electricity consumption, depreciation and labor wages. Compared with the total cost, refrigeration and power electricity account for 25% to 40%, warehouse roof and refrigeration equipment depreciation account for about 25% to 35%, production workers' wages and surcharges account for about 0% to 15%, and the above three expenses account for about 60% to 90% of the total cost. Therefore, saving electricity and improving the utilization rate and labor productivity of cold storage are the key to reducing the cost of cold storage. A large part of the electricity consumption of cold storage comes from defrosting. Frosting in cold storage is caused by the temperature of the cold storage. Below 0℃, the surface of the air cooler evaporator is often lower than the temperature of the cold storage, and it will absorb moisture in the cold storage and frost, thereby reducing the heat transfer efficiency. Poor heat exchange effect means high energy consumption, and the cooling speed of the storage temperature will also slow down, and its energy consumption will increase by more than 30%. When frosting is serious, the heat exchange effect is greatly reduced, and the storage temperature will no longer drop. At the same time, insufficient evaporation of the refrigerant will cause liquid hammer failure of the refrigeration compressor unit outside the storage, which will cause huge economic losses to the cold storage company. In the process of use, the existing frost-free freezing and refrigeration system has many problems or defects:

[0003] In the actual use of traditional frost-free freezing and refrigeration systems, cold air blowers (coolers) operating at sub-zero temperatures in cold storages at home and abroad are all equipped with defrosting devices, such as hot water defrosting, refrigerant heat recovery defrosting, electric defrosting, etc., which all require high temperature and frequent storage operations, and the defrosting process is the reverse process of refrigeration, which requires a large amount of cold storage capacity. At the same time, the heat brought into the cold storage will increase the temperature in the cold storage, causing fluctuations in the storage temperature, especially in small and medium-sized cold storages, where the temperature fluctuation can reach more than 1°C, which will seriously affect the preservation effect and quality of the stored goods. The following table shows the impact of the frost layer on the refrigeration efficiency. The refrigeration efficiency decreases due to frost, as shown in Table 1:

[0004] Table 1: Variation of evaporation temperature and refrigeration coefficient with frost layer when refrigeration load remains constant

[0005]

[0006] There are five common defrosting methods:

[0007] 1. Use compressed air for defrosting, because the mid-term defrosting of the continuous freezing food quick-freezing device during operation (generally using hot air defrosting + water defrosting) will seriously affect the production capacity of the device, waste production materials and increase production costs (because other production workers also have to be on standby during the defrosting period), and the frost-free quick-freezing technology can solve the various disadvantages of mid-term defrosting.

[0008] 2. The manual defrosting method is that the operator uses a cleaning tool to directly remove the condensed frost on the surface of the evaporator. This method is called manual defrosting. It is generally only suitable for defrosting the wall and top pipes of frozen cold storage. The frozen cold storage room is a cold storage room for long-term storage. The pipes are on the top of the goods or close to the surrounding of the goods. If hot air defrosting or electric heating defrosting is used, the melting of the frost will not only make the goods damp, but also stick the goods into blocks. The working conditions of manual defrosting are very poor. In addition to increasing the cost of workers, they also need to be equipped with cold-proof clothing for defrosting workers. Therefore, a scientific balance method must be used to determine whether it is reasonable to increase labor costs by manual defrosting or to increase the operating electricity costs. This depends on which is more cost-effective and a reasonable defrosting cycle should be formulated.

[0009] 3. Use water spray to defrost. Install the water spray pipe above the evaporator. When defrosting, spray water with a certain pressure evenly onto the surface of the frost layer through the water spray pipe. This defrosting method is called water flushing. The water flushing method can only be used for defrosting of air coolers. It is generally used in combination with hot air defrosting. When used alone, it is only suitable for situations where the frosting speed of the air cooler is slow and the frost layer is relatively thin, such as defrosting of air coolers in cooling and refrigerating rooms. This method is simple and easy to implement, but its defrosting cost is too high, and it consumes a lot of electricity and water.

[0010] 4. Hot gas defrosting. Since most food cold storages currently use ammonia refrigeration systems, hot gas defrosting is also called hot ammonia defrosting. This method is to introduce the compressor exhaust after oil filtration through the oil separator into the evaporator, and use the sensible heat and latent heat of the refrigerant to heat and melt the frost on the outer surface of the evaporator, so as to achieve the purpose of defrosting. The original low-temperature refrigerant liquid in the evaporator must be removed before defrosting. Therefore, the refrigeration system of hot ammonia defrosting needs to be equipped with drainage facilities to receive the residual liquid in the evaporator before defrosting and the liquid condensed by the refrigerant during the defrosting process. The advantage of hot gas (refrigerant) defrosting is energy saving, because in the normal refrigeration cycle, the hot ammonia gas needs to be cooled with cooling water to liquefy it. In the hot gas defrosting process, the frost plays the role of cooling water while being melted. At this time, the evaporator becomes a condenser that does not require cooling water, and does not consume electricity during defrosting. Compared with electric heating defrosting and water defrosting, it has a double energy-saving effect. The disadvantage of this method is that the system is relatively complicated, and a drainage bucket must be specially set up in the system to hold the liquid or a low-circulation bucket must be used to hold the liquid.

[0011] 5. Electric defrosting: This defrosting method is to wrap the heating wire around the surface of the evaporator, and the defrosting time is controlled by a time relay. The advantage is that the method is simple and easy to implement, and it is easiest to automate. The main disadvantage is energy consumption. The defrosting method that simply uses electric heat to melt the frost layer has the highest energy consumption cost of all methods. In the refrigeration system of large and medium-sized cold storages, the pure thermoelectric defrosting method is generally rarely used. In the refrigeration system with a high degree of automation and good automatic oil return of the evaporator.

[0012] Defrosting is usually a troublesome thing. The above five commonly used defrosting methods have more or less deficiencies and defects. In order to achieve frost-free refrigeration, many scientific and technological workers have explored and invented a variety of new technologies for frost-free cold storage. Here is an introduction to the invention patent of "a high-humidity frost-free cold storage" applied by Shandong Fruit Research Institute. The patented technology includes a refrigeration compressor unit and a cold air machine (cooler). The refrigeration compressor unit is connected to the cold air machine, and the cold air machine (cooler) is arranged in the cold storage. It is characterized by also including a liquid storage tank, a circulating pump, a spray pipe, etc. The liquid storage tank is arranged at the bottom of the cold storage, and a low freezing point solution is placed in the liquid storage tank. The evaporator is immersed in the low freezing point solution. The liquid storage tank is provided with a feeding port, a liquid feeding port and a liquid discharge port leading to the outside of the cold storage. The liquid inlet of the circulating pump extends into the low freezing point solution in the liquid storage tank through a pipeline. The liquid outlet of the circulating pump is connected to the spray pipe arranged on the upper side of the cold air machine in the cold storage through a pipeline, and can spray the cold air machine and the inner wall of the cold storage. In order to improve the refrigeration effect, a liquid sprinkling device is provided in the cold storage. The liquid sprinkling device includes a circulating pump and a spray pipe. The liquid inlet of the circulating pump extends into the refrigerant in the shallow pool at the bottom of the cold storage through a pipeline, and the liquid outlet of the circulating pump is connected to the spray pipe through a pipeline. The spray pipe is provided in the upper part of the cold storage. The circulating pump sends the refrigerant cooled by the evaporative exhaust pipe in the shallow pool of the cold storage to the spray pipe, which sprays into the cold storage through the spray pipe, thereby accelerating the cooling speed and improving the refrigeration effect, and reducing the temperature difference in the cold storage. It can prevent the evaporator (cooler) of the air cooler from frosting, and can also humidify the cold storage, increase the humidity in the cold storage, keep the storage temperature relatively constant, reduce the number of times the refrigeration compressor is turned on and off, save energy, extend the life of the equipment, and improve the refrigeration efficiency, that is, frost-free, and high humidity. However, low freezing point solution must be continuously added to prevent its freezing point temperature from rising and freezing. At the same time, there will be problems such as the loss of low freezing point solution and contamination of water and soil. Similarly, the cooler is also indispensable. The evaporator in the liquid storage tank in the cold storage is far away from the compressor, so the refrigerant circulation distance is also very long, and the refrigerant flow resistance is large, which is bound to greatly reduce the refrigerant circulation efficiency and increase the power consumption of the compressor. This is also a common problem of existing cold storage technology. Summary of the invention

[0013] The object of the present invention is to provide a frost-free freezing and refrigerating storage system to solve the problems raised in the above-mentioned background technology.

[0014] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a frost-free freezing cold storage system, comprising an antifreeze spray heat exchanger arranged in the cold storage and a refrigeration unit arranged outside the cold storage, the refrigeration unit comprising a cooling tower, a cooling circulation pump connected to the cooling tower at one end, the other end of the cooling circulation pump is connected to the refrigeration unit condenser, and also comprising a refrigeration unit evaporator, a refrigeration unit compressor and a refrigeration unit throttling device arranged in series between the refrigeration unit evaporator and the refrigeration unit condenser, the refrigeration unit compressor drives the refrigerant in the cooling tower to circulate between the refrigeration unit evaporator and the refrigeration unit condenser, one end of the refrigeration unit evaporator is connected to the antifreeze spray heat exchanger through a refrigerant circulation pump, the antifreeze spray heat exchanger absorbs the heat in the cold storage and then flows into the refrigerant overflow tank, the refrigerant overflow tank is connected to the refrigeration unit evaporator, the refrigerant in the refrigerant overflow tank is sucked into the refrigeration unit evaporator and releases latent heat to be cooled, thereby completing the open circulation of the system refrigerant.

[0015] Preferably, the antifreeze spray heat exchanger includes a supercooled air duct space with a heat exchanged air inlet fan (fan), an antifreeze spray chamber and an antifreeze spray pipe, an air outlet is provided at the top of the antifreeze spray chamber, and the air inlet (return air outlet) is facing the frozen goods space, the air outlet is installed with a fan, the lower part of the antifreeze spray pipe is the antifreeze spray chamber, and a spray chamber baffle is installed on the side of the antifreeze spray chamber close to the wall, an antifreeze tray is provided at the bottom of the antifreeze spray chamber, the supercooled air duct space is connected to the fan space, an antifreeze outlet is provided at the bottom of the antifreeze tray, and a supercooled air duct space is formed on the side of the spray chamber baffle away from the return air outlet and the surrounding wall of the antifreeze spray chamber.

[0016] Preferably, the fan used in the antifreeze spray heat exchanger is a cross-flow fan, a centrifugal fan or an axial flow fan, the motor is arranged on the outer wall of the antifreeze spray heat exchanger, and a protective cover is provided to shield the splash of antifreeze.

[0017] Preferably, the antifreeze liquid spray heat exchanger is made of anti-corrosion materials.

[0018] Preferably, the surface of the antifreeze liquid spray heat exchanger is provided with an anti-corrosion coating.

[0019] Preferably, the coolant overflow tank is connected to the evaporator of the refrigeration unit via a dilute antifreeze storage tank, a dilute antifreeze concentration device and a concentrated antifreeze delivery pump in sequence.

[0020] Preferably, a liquid level controller is installed at the inner bottom of the dilute antifreeze liquid storage tank.

[0021] Preferably, the antifreeze in the dilute antifreeze storage tank is concentrated using negative pressure low-temperature concentration technology.

[0022] Preferably, the coolant in the coolant overflow tank is a calcium chloride aqueous solution, and a corrosion inhibitor is added to the solution.

[0023] Preferably, the pipe connecting the evaporator of the refrigeration unit and the refrigerant overflow tank is inserted into the refrigerant overflow tank.

[0024] Compared with the prior art, the beneficial effects of the present invention are: the frost-free freezing and refrigerating storage system has the following advantages:

[0025] (1) It can save more than 30% energy than the existing water-cooled cold storage and even more energy than the air-cooled cold storage;

[0026] (2) There is no loss of antifreeze (coolant), and no loss of defrosting brine. The water consumption is very small, which has a strong environmental advantage;

[0027] (3) It can transport cold air over long distances and has the advantage of large-scale application.

[0028] (4) Under the condition of the same scale of cold storage refrigeration capacity, the investment cost of refrigeration equipment can be reduced by more than 15% due to its high refrigeration efficiency and the use of antifreeze spray heat exchanger.

[0029] (5) No need for defrosting, saving labor costs and reducing labor intensity.

[0030] (6) Refrigeration equipment takes up little space, the equipment can be centrally arranged, cold air can be transported over long distances, and centralized management of the equipment becomes possible.

[0031] (7) The temperature fluctuation in the cold storage is extremely small, and the temperature control can be accurate and timely. There is no temperature blind spot, which has the advantage of ensuring the quality of frozen and refrigerated meat, fruits and vegetables.

[0032] (8) Reduce the failure rate of cold storage refrigeration equipment and extend the service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the process of the present invention;

[0034] Figure 2 It is a structural schematic diagram of the antifreeze liquid spray heat exchanger of the present invention;

[0035] In the figure: 1. Cold storage; 2. Antifreeze spray heat exchanger; 3. Refrigeration unit evaporator; 4. Coolant overflow tank; 5. Dilute antifreeze storage tank; 6. Cooling tower; 7. Coolant circulation pump; 8. Refrigeration unit compressor; 9. Refrigeration unit condenser; 10. Refrigeration unit throttling device; 11. Antifreeze concentration device; 12. Cooling circulation pump; 13. Concentrated antifreeze delivery pump; 14. Supercooled air duct space; 15. Spray chamber liquid baffle; 16. Antifreeze outlet; 17. Fan; 18. Antifreeze spray pipe; 19. Antifreeze tray; 20. Antifreeze spray chamber; 21 Return air; 22 Outlet air. DETAILED DESCRIPTION

[0036] 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. In the present invention, the coolant and the antifreeze liquid both indicate the same object.

[0037] See also Figure 1-2 , an embodiment of the present invention: a frost-free freezing cold storage system, including an antifreeze spray heat exchanger 2 arranged in a cold storage 1 and a refrigeration unit arranged outside the cold storage, the antifreeze spray heat exchanger 2 is provided with several, the refrigeration unit includes a cooling tower 6, a cooling circulation pump 12 connected to the cooling tower at one end, the other end of the cooling circulation pump is connected to the refrigeration unit condenser 9, and also includes a refrigeration unit evaporator 3, a refrigeration unit compressor 8 and a refrigeration unit throttling device connected in series between the refrigeration unit evaporator and the refrigeration unit condenser 10. The compressor of the refrigeration unit drives the refrigerant in the cooling tower to circulate between the evaporator 3 of the refrigeration unit and the condenser 9 of the refrigeration unit. One end of the evaporator of the refrigeration unit is connected to several antifreeze spray heat exchangers 2 through a refrigerant circulation pump 7. The antifreeze spray heat exchanger absorbs the heat in the cold storage and flows into the refrigerant overflow tank 4. The refrigerant overflow tank is connected to the evaporator of the refrigeration unit. The refrigerant in the refrigerant overflow tank is sucked into the evaporator of the refrigeration unit and releases latent heat to be cooled, thereby completing the open circulation of the system refrigerant;

[0038] Specifically, Figure 1 and Figure 2As shown, when in use, when the system cooling circulation pump 12 and the refrigerant circulation pump 7 are started, the refrigeration unit compressor 8, the refrigeration unit throttling device 10 and the cooling tower 6 start to work, and the refrigeration unit compressor 8 drives the refrigerant to circulate between the refrigeration unit evaporator 3 and the refrigeration unit condenser 9, and the operation of the cooling tower 6 and the cooling circulation pump 12 can transfer the latent heat released by the refrigerant in the refrigeration unit condenser 9 to the air outside the cold storage 1, and the refrigerant is condensed. After condensation, the refrigerant passes through the refrigeration unit throttling device 10 again and enters the refrigeration unit evaporator 3 to absorb the latent heat of the other refrigerant in the refrigeration unit evaporator 3, and the gaseous refrigerant is pressed into the refrigeration unit condenser 9 by the refrigeration unit compressor 8 to realize the circulation of the refrigerant. The refrigerant circulation pump 7 pumps the refrigerant after releasing the latent heat into each antifreeze spray heat exchanger 2 of the cold storage 1 for spraying, and absorbs the heat of the air in the storage and condenses the water vapor in the air and dilutes its latent heat before flowing into the refrigerant overflow tank 4, and then is sucked into the evaporator of the refrigeration unit through the pipe inserted into the refrigerant overflow tank 4 and connected to the evaporator of the refrigeration unit to release the latent heat to the refrigerant on the other side of the evaporator of the refrigeration unit, thereby realizing the circulation process of the refrigerant. There is no loss of antifreeze (refrigerant), and no loss of defrosting brine, and the water consumption is very small, which has a strong environmental advantage;

[0039] The coolant overflow tank is connected to the evaporator 3 of the refrigeration unit through the dilute antifreeze storage tank 5, the dilute antifreeze concentration device 11 and the concentrated antifreeze delivery pump 13 in sequence. A liquid level controller is installed inside the dilute antifreeze storage tank 5. The antifreeze concentration device 11 adopts negative pressure low-temperature concentration technology and negative pressure evaporation achieved by a water ring vacuum pump or a jet pump to achieve the purpose of mass transfer and heat transfer concentration, and the heat of cooling water is used to heat the dilute antifreeze, thereby reducing the energy consumption required for cooling and reducing the energy consumption required for concentration.

[0040] When in use, the pipe connected to the evaporator 3 of the refrigeration unit inserted into the bottom area of ​​the brine overflow tank 4 can absorb the brine into the evaporator 3 of the refrigeration unit to release latent heat again and get cooled, thereby completing the circulation process of the brine. The brine absorbs the heat of the air in the warehouse and also absorbs the water vapor in the air into the brine solution, making the concentration of the brine solution further diluted. The mass of the diluted antifreeze will increase and overflow from the brine overflow tank 4 into the dilute antifreeze storage tank 5. The dilute antifreeze storage tank 5 can also be used as a concentrated antifreeze adding device. When the liquid level of the dilute antifreeze storage tank 5 reaches a certain height, it indicates that the antifreeze is diluted to a certain extent.

[0041] When the antifreeze is diluted to a certain extent and there is a danger of freezing the pipes, the liquid level controller can be used to give an alarm, or instruct the refrigeration unit to shut down urgently, or add concentrated antifreeze, or instruct the antifreeze concentration device 11 to concentrate the dilute antifreeze. The concentrated antifreeze is pumped into the evaporator 3 of the refrigeration unit through the concentrated antifreeze delivery pump 13, and part of the cooling water coming out of the condenser 9 of the refrigeration unit can be used to heat the dilute antifreeze, so as to improve the efficiency of evaporating and concentrating the dilute antifreeze, and at the same time can also play a role in lowering the cooling water temperature, thereby improving the effect of condensing the refrigerant.

[0042] The coolant is calcium chloride solution. Since calcium chloride solution has a large specific heat capacity, low purchase cost, is non-toxic, and does not affect the quality of meat, fruits and vegetables in the cold storage, solid calcium chloride can also be used as a food moisture-proof powder, and corrosion inhibitors are added to this solution;

[0043] In particular, the antifreeze spray heat exchanger 2 has a strong cold transport capacity. The antifreeze spray heat exchanger 2 includes a supercooled air duct space 14 of a heat exchanged inlet fan (fan), an antifreeze spray chamber 20 and an antifreeze spray pipe 18. An air outlet is provided at the top of the antifreeze spray chamber, and the air inlet (return air outlet) facing the frozen goods space is the antifreeze spray chamber. The antifreeze spray chamber is just below the spray pipe 18, between the return air outlet and the liquid baffle 15. A fan 17 is installed at the air outlet of the antifreeze spray heat exchanger. The fan can be a cross-flow fan, a centrifugal fan or an axial flow fan. A spray chamber baffle 15 is installed on the antifreeze spray chamber near the wall side. An antifreeze tray 19 is provided at the bottom of the antifreeze spray chamber. The antifreeze liquid spray heat exchanger 2 is connected to the fan space, and the bottom of the antifreeze liquid spray room is provided with an antifreeze liquid outlet 16 connected to the antifreeze liquid tray. The side of the spray room liquid baffle 15 away from the return air port forms an overcooled air duct space with the antifreeze liquid spray room wall. The antifreeze liquid spray heat exchanger 2 uses the refrigerant circulating pump 7 to force the antifreeze liquid into the antifreeze liquid spray pipe 18 for spraying to absorb the heat of the return air 21 (the cold air entering the spray room). After successfully absorbing heat, it falls into the antifreeze liquid tray 19, and then enters the antifreeze liquid reflux main pipe through the antifreeze liquid outlet 16 at the bottom of the antifreeze liquid tray 19. The antifreeze liquid then flows into the refrigerant overflow tank 4 through the reflux main pipe (if the refrigerant overflow tank is located at a higher position, a booster pump can be set on the reflux main pipe). The cooled air passes through the spray chamber baffle 15 and enters the supercooled air duct space 14 behind the spray baffle, and is then blown out by the fan 17, becoming a lower supercooled outlet air 22 (the air out of the antifreeze spray heat exchanger is supercooled air). The air inlet and outlet of the antifreeze spray heat exchanger must face the items in the warehouse to prevent the cold air from bringing out the antifreeze droplets and affecting the equipment and facilities in the warehouse, and to prevent the equipment from being corroded by the antifreeze. Therefore, the wall of the antifreeze spray heat exchanger must be made of anticorrosive materials or sprayed with anticorrosive paint, and backed against the cold storage wall. The cold storage wall can also be used as one side of the wall. This setting method can prevent the antifreeze from splashing to other places, especially the fan motor must be set outside the wall and equipped with a protective cover or shielding device. In addition, the antifreeze spray heat exchanger can also use a filler falling film method to increase the contact area with the air. There is no drawing here, and it is only explained in text.

[0044] Working principle: When in use, first of all, it does not need to set up a cooler (evaporator) in the warehouse, nor does it need to set up a liquid storage tank, and it is not necessary to put the evaporator in the tank. Instead, the cooler is changed to an antifreeze spray heat exchanger 2. The refrigerant directly passes through the evaporator 3 of the refrigeration unit to release latent heat. The cooled refrigerant can directly exchange heat with the air in the warehouse to cool the air in the warehouse. Unlike the existing cold storage unit system pipeline connecting the cooler to form a closed refrigerant cycle, or the connected cooler to form a closed antifreeze cycle, the different temperature requirement areas in the warehouse can be controlled by the refrigerant flow and antifreeze The number and size of the liquid spray heat exchanger 2 can be controlled, and the problem of the freezing point temperature shifting upward in the refrigerant absorption storage can be well solved by the corresponding technical solution. The evaporator can be prevented from freezing pipes by concentrating the dilute antifreeze or adding concentrated antifreeze. This can not only achieve the various benefits brought by frost-free freezing and refrigeration, but also reduce investment costs and save the operating costs of the cold storage 1. There is no labor cost for defrosting, especially no need for defrosting, no energy consumption for defrosting, and the water consumption of the cold storage 1 is also very small, and there is no problem of water and soil pollution by defrosting brine;

[0045] Secondly, the efficiency of the refrigeration process is improved, which is energy-saving in multiple senses. First of all, it is energy-saving without defrosting. The more important energy saving is that the heat exchange efficiency between the antifreeze spray heat exchanger 2 and the air in the warehouse is very high. The antifreeze and the air in the warehouse directly exchange heat, unlike the cooler, which has the thermal resistance of the heat exchange partition. The thermal resistance of the partition affects its heat exchange effect. This technology also has the advantage of a large heat exchange area, because the surface area of ​​the spray liquid is much larger than the heat exchange surface area of ​​the cooler (tubular fins). Although both use a cross-flow heat exchange method, the antifreeze spray heat exchanger 2 is in the form of many liquid droplets in parallel with the air for heat exchange contact, while the tubular fins are multiple pipes connected in series to form a serpentine tube heat exchange. Obviously, the series thermal resistance is greater than the parallel thermal resistance, and the heat flux density per unit time of the coolant is much greater than that of the refrigerant (refrigerant) per unit time. Heat flux density (in the case of phase change heat transfer, although the heat flux density per unit mass of refrigerant is greater than that of antifreeze), the overall heat flux density is much smaller than that which can be achieved by circulating pump transportation, especially the long-distance medium transportation of compressor is far less cost-effective than that of circulating pump. Compressor is only suitable for transporting gaseous medium, and the density of gaseous medium is much smaller than that of liquid medium. Therefore, under the same power consumption, the mass of medium transported by circulating pump is more than one hundred times that of compressor, and thus the cooling capacity transported is also many times different. Under the same cooling capacity, the compressor will have to overcome much more fluid pressure and resistance than the circulating pump, because the longer the pipeline distance, the greater the pipe wall resistance, and the gas pressure will be greater than the relative pressure of the liquid. This is why water-cooled air conditioners are much more energy-efficient than air-cooled multi-split units.

[0046] In short, it is a combination of factors that lead to the antifreeze spray heat exchanger 2 being much more energy-efficient than the closed cooler, thus demonstrating its huge energy-saving advantage, as well as the advantage of large-scale application (because the circulating pump can transport cold air over long distances, but the compressor cannot). From the perspective of investment cost, the cooler (evaporator) is more than 50% higher than the antifreeze spray heat exchanger 2.

[0047] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

Claims

1. A frost-free freezing and refrigerating storage system, characterized in that: The invention comprises an antifreeze liquid spray heat exchanger (2) arranged in a cold storage (1) and a refrigeration unit arranged outside the cold storage, wherein the refrigeration unit comprises a cooling tower (6), a cooling circulation pump (12) connected to the cooling tower at one end, and the other end of the cooling circulation pump is connected to a refrigeration unit condenser (9), and further comprises a refrigeration unit evaporator (3), a refrigeration unit compressor (8) arranged in series between the refrigeration unit evaporator and the refrigeration unit condenser, and a refrigeration unit throttling device (10), wherein the refrigeration unit compressor drives the refrigeration unit to The antifreeze agent circulates between the refrigeration unit evaporator (3) and the refrigeration unit condenser (9), one end of the refrigeration unit evaporator is connected to the antifreeze liquid spray heat exchanger (2) through a refrigerant circulating pump (7), the antifreeze liquid spray heat exchanger absorbs the heat in the cold storage and then flows into the refrigerant overflow tank (4), the refrigerant overflow tank is connected to the refrigeration unit evaporator, the refrigerant in the refrigerant overflow tank is sucked into the refrigeration unit evaporator and releases latent heat to be cooled, thereby completing the open circulation of the system refrigerant; The antifreeze liquid spray heat exchanger (2) comprises an air duct space (14) for supercooled air entering a blower after heat exchange, an antifreeze liquid spray chamber (20) and an antifreeze liquid spray pipe (18); an air outlet is provided at the top of the antifreeze liquid spray chamber (20); a return air outlet is provided at the part facing the frozen goods space; a fan (17) is installed at the air outlet; the lower part of the antifreeze liquid spray pipe (18) is the antifreeze liquid spray chamber; a spray chamber baffle plate (15) is installed on the side of the spray chamber close to the wall; an antifreeze liquid tray (19) is provided at the bottom of the antifreeze liquid spray chamber; the supercooled air duct space (14) is connected to the fan space; an antifreeze liquid outlet (16) is provided at the bottom of the antifreeze liquid tray; a side of the spray chamber baffle plate (15) away from the return air outlet forms a supercooled air duct space (14) with the surrounding wall of the antifreeze liquid spray chamber; The coolant overflow tank is connected to the evaporator (3) of the refrigeration unit via a dilute antifreeze storage tank (5), a dilute antifreeze concentration device (11) and a concentrated antifreeze delivery pump (13) in sequence; The pipe connecting the evaporator (3) of the refrigeration unit and the refrigerant overflow tank (4) is inserted into the refrigerant overflow tank (4).

2. A frost-free freezing and refrigerating storage system according to claim 1, characterized in that: The fan (17) used in the antifreeze liquid spray heat exchanger (2) is a cross-flow fan, a centrifugal fan or an axial flow fan. The motor is arranged on the outer wall of the antifreeze liquid spray heat exchanger and is provided with a protective cover capable of shielding the splashing of the antifreeze liquid.

3. A frost-free freezing and refrigerating storage system according to claim 1, characterized in that: The antifreeze liquid spray heat exchanger (2) is made of anti-corrosion materials.

4. A frost-free freezing and refrigerating storage system according to claim 1, characterized in that: The surface of the antifreeze liquid spraying heat exchanger (2) is provided with an anti-corrosion coating.

5. A frost-free freezing and refrigerating storage system according to claim 1, characterized in that: A liquid level controller is installed at the inner bottom of the dilute antifreeze liquid storage tank (5).

6. A frost-free freezing and refrigerating storage system according to claim 1, characterized in that: The antifreeze liquid in the dilute antifreeze liquid storage tank (5) is concentrated by using negative pressure low temperature concentration technology.

7. A frost-free freezing and refrigerating storage system according to claim 1, characterized in that: The coolant in the coolant overflow tank is a calcium chloride aqueous solution, and a corrosion inhibitor is added to the solution.

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