Rapid pre-cooling anti-freezing device for yak milk producing area and control method

Abstract

The invention relates to the technical field of pre-cooling preservation of dairy products, and provides a quick pre-cooling anti-freezing device for a yak milk producing area and a control method. A material cavity is formed in the tank body, the material cavity is sleeved with a first heat exchange cavity and a second heat exchange cavity from inside to outside, and a food-grade propylene glycol aqueous solution and a 0-DEG C phase change material are poured into the material cavity to serve as cooling capacity transfer media; the heat exchange assembly comprises a first heat exchange refrigerant pipe arranged in the first heat exchange cavity and a second heat exchange refrigerant pipe arranged in the second heat exchange cavity. The controller quickly precools the first heat exchange cavity and precisely cools the second heat exchange cavity, so that the yak milk in the material cavity is quickly precooled, and double anti-freezing and precise cooling are realized. Two-section heat exchange is adopted, so that the problem of local supercooling during single-medium low-temperature heat exchange is avoided, the pre-cooling efficiency is improved through the gradient design of first fast and then stable, large-scale and short-time yak milk pretreatment in a production place is adapted, and the retention and deterioration risk of raw milk at normal temperature is reduced.

Description

Technical Field

[0001] This invention relates to the field of dairy product pre-cooling and preservation technology, and in particular to a rapid pre-cooling and antifreeze device and control method for yak milk at its place of origin. Background Technology

[0002] Yaks are even-toed ungulates belonging to the genus *Bos* in the family Bovidae. They feed on natural pastures and primarily inhabit high-altitude plateau regions, generally above 3000 meters. The favorable ecological environment for yaks ensures the natural and green quality of yak milk. The nutritional components of yak milk (dry matter content, milk fat content, milk protein, and calcium content) are all higher than those of regular cow's milk. It also contains higher levels of various vitamins, nicotinic acid, and carotenoids. In particular, the levels of lactoferrin and immunoglobulins even exceed those of bovine colostrum and breast milk. With economic development and increasing health awareness, consumer demand for green, natural, and nutritious dairy products has exploded. Driven by this consumer trend, the yak farming industry has ushered in unprecedented development opportunities. Local governments have increased their support for yak farming, encouraging herders to expand their operations and improve their farming techniques through policy guidance and subsidies. Yak milk production has also steadily increased with the expansion of farming scale and the advancement of farming techniques.

[0003] With the expansion of yak farming and the growth of market demand, yak milk production has been steadily increasing. However, the processing and preservation of yak milk has become increasingly prominent, becoming a bottleneck restricting the further development of the industry. Currently, with strong government support and the active promotion of relevant enterprises, milk stations have been established in concentrated yak grazing areas in agricultural and pastoral regions. These stations are equipped with advanced testing and refrigeration equipment. Staff at the milk stations conduct rigorous testing on each batch of delivered yak milk, including alcohol tests, physicochemical indicators, and antibiotic tests. Only yak milk that fully meets the current raw milk purchase standards is purchased. After being filtered and pre-cooled to a suitable temperature, the fresh yak milk is temporarily stored in refrigerated storage tanks at a constant temperature of 2-6℃, awaiting subsequent transfer to processing plants.

[0004] After fresh yak milk is milked, farmers and herders typically use ice water cooling, simple refrigeration equipment, or natural cooling to quickly lower the milk temperature and inhibit microbial growth. The milk is then packed into insulated containers and transported to nearby milk collection stations. However, during this process, the yak milk temperature exceeds 10°C, causing the lactic acid bacteria, E. coli, and other microorganisms it contains to proliferate rapidly. This not only decomposes lactose and protein, producing unpleasant flavors such as sourness and off-flavors, and disrupting colloidal stability, leading to separation and coagulation, but also directly threatens the safety of yak milk for consumption due to the excessive proliferation of harmful microorganisms. However, because most farmers and herders live scattered and lack professional pre-cooling and refrigeration equipment at the production site, it is impossible to guarantee that fresh yak milk can quickly reach the appropriate refrigeration temperature after milking. If the transportation distance is long, the quality of the milk during storage and transportation becomes difficult to guarantee, which directly limits the milk collection area of ​​milk collection stations. This limited collection area not only affects the stable supply of raw materials to milk collection stations but also restricts the large-scale development of the entire yak dairy industry, making it difficult to meet the growing market demand.

[0005] In the rapid cooling and storage of yak milk, cell protection technology is the core key to maintaining its quality and freshness. Current traditional yak milk pre-cooling equipment generally suffers from slow pre-cooling rates and low overall efficiency. However, using rapid cooling technology for pre-cooling can promote the formation of smaller ice crystals from residual water in the milk, effectively reducing the probability of cell wall rupture. When accelerating the pre-cooling of yak milk through large temperature difference heat transfer, strict temperature control is necessary to avoid crystallization caused by excessively low temperatures, which can damage the cell walls. If the ice crystals are too large or too numerous, they can directly cause cell wall rupture, leading to loss of nutrients, a deterioration in taste, and a significant decline in overall quality.

[0006] Therefore, it is urgent to find an efficient and reliable pre-cooling device and method for yak milk at its origin. Pre-cooling at the origin can ensure the quality of yak milk from the source, eliminating farmers' and herders' worries about milk spoilage and effectively guaranteeing their income. Milk stations will be able to absorb more scattered high-quality milk sources, achieving large-scale and stable raw material supply, thereby laying a solid foundation for the large-scale and intensive development of the industry and promoting the sustainable and healthy development of the yak milk industry. Summary of the Invention

[0007] In order to overcome or alleviate one or more of the above technical problems, the purpose of this invention is to provide a rapid pre-cooling and antifreeze device and control method for yak milk production areas.

[0008] This invention provides the following technical solution:

[0009] A rapid pre-cooling and antifreeze device for yak milk production areas, comprising:

[0010] The main unit (100) and the precooling tank (200) are mounted on the support (103). The tank body (201) of the precooling tank (200) is provided with a material chamber (205). The material chamber (205) is provided with a first heat exchange chamber (206) and a second heat exchange chamber (207) from the inside to the outside. The material chamber (205) is used to hold yak milk to be precooled. The first heat exchange chamber (206) and the second heat exchange chamber (207) are respectively filled with food-grade propylene glycol aqueous solution and 0℃ phase change material as cold energy transfer medium.

[0011] The heat exchange assembly includes a first heat exchange refrigerant pipe (118) disposed in the first heat exchange chamber (206) and a second heat exchange refrigerant pipe (117) disposed in the second heat exchange chamber (207).

[0012] The controller (102) is electrically connected to the refrigeration component, the heat exchange component, and the sensor component, respectively. The sensor component includes multiple distributed temperature sensors for collecting temperature signals in the material chamber (205), the first heat exchange chamber (206), and the second heat exchange chamber (207), respectively. The controller (102) and the refrigeration component are located inside the main unit housing (100).

[0013] The refrigeration component and the heat exchange component are connected through a refrigerant pipeline. The controller (102) controls the refrigeration component to cool and transport the refrigerant according to the temperature signal returned by the sensor component. By rapidly pre-cooling or heating the first heat exchange chamber (206) and precisely cooling the second heat exchange chamber (207), the yak milk in the material chamber (205) is rapidly pre-cooled, precisely cooled, and double-frozen.

[0014] When the sensor assembly obtains that the real-time temperature of the yak milk in the material chamber (205) is ≤4℃ or less than the set maximum temperature for pre-cooling the yak milk, and the real-time temperature of the first heat exchange chamber (206) is <0℃, the controller (102) controls the first heat exchange refrigerant pipe (118) of the heat exchange assembly to heat the first heat exchange chamber (206) according to the temperature signal returned by the sensor assembly, and utilizes the constant temperature heat exchange characteristics of the 0℃ phase change material of the second heat exchange chamber (207) to achieve dual-chamber temperature control and dual antifreeze.

[0015] Preferably, the inlet end of the first heat exchange refrigerant pipe (118) is provided with a first heat exchange inlet solenoid valve (111), and the outlet end is provided with a first heat exchange electronic expansion valve (112) and a first heat exchange outlet solenoid valve (110).

[0016] The inlet end of the second heat exchange refrigerant pipe (117) is provided with a second heat exchange inlet solenoid valve (113) and a second heat exchange electronic expansion valve (114), and the outlet end is provided with a second heat exchange check valve (116) and a second heat exchange outlet solenoid valve (115). The remaining components of the heat exchange assembly, except for the first and second heat exchange refrigerant pipes, and the refrigerant pipes between them are located in the support (103).

[0017] Preferably, the refrigeration assembly includes a four-way valve (105), which is used to switch the flow direction of the refrigerant. The four inlets and outlets of the four-way valve (105) are connected to the compressor (104), the gas-liquid separator (119), the bidirectional liquid receiver (109), the first heat exchange outlet solenoid valve (110), and the second heat exchange outlet solenoid valve (115) respectively through refrigerant pipes. The compressor (104) compresses the gaseous refrigerant, increases its pressure and temperature, and promotes the refrigerant circulation. The compressor (104) is connected to the bidirectional liquid receiver (109), the four-way valve (105), and the gas-liquid separator (119) respectively through refrigerant pipes. The gas-liquid separator (119) is used to separate the incompletely evaporated liquid refrigerant in the refrigerant pipe. The gas-liquid separator (119) is connected to the four-way valve (105) and the compressor (104) respectively through refrigerant pipes. The bidirectional liquid receiver (109) is used to store... The refrigerant liquid in the condenser heat exchanger (106) or the first heat exchange refrigerant pipe (118) is stored, and gas-liquid separation, drying and filtration are achieved. One end of the two-way liquid reservoir (109) is connected to the antifreeze electronic expansion valve (108), the two-way drying filter (107) and the condenser heat exchanger (106) in sequence through the refrigerant pipe. The other end of the two-way liquid reservoir (109) is divided into two paths through the refrigerant pipe. One path is connected to the first heat exchange inlet solenoid valve (111), the first heat exchange electronic expansion valve (112), the first heat exchange refrigerant pipe (118) and the first heat exchange outlet solenoid valve (110) through the refrigerant pipe. The other path is connected to the second heat exchange inlet solenoid valve (113), the second heat exchange electronic expansion valve (114), the second heat exchange refrigerant pipe (117), the second heat exchange check valve (116) and the second heat exchange outlet solenoid valve (115) through the refrigerant pipe.

[0018] Preferably, the controller (102) controls the refrigeration component to cool and transfer the refrigerant based on the temperature signal returned by the sensor component, and cools through the first and second heat exchange refrigerant pipes. The control modes include rapid cooling cycle, antifreeze cycle, precise cooling cycle, and cold storage cycle. Under different cycle states, the working process of the refrigeration component and the heat exchange component is as follows:

[0019] Rapid cooling cycle: The refrigerant circulates in the refrigeration components, the first heat exchange inlet solenoid valve (111), the first heat exchange electronic expansion valve (112), the first heat exchange refrigerant pipe (118), and the first heat exchange outlet solenoid valve (110). After absorbing heat in the first heat exchange chamber (206), the low-temperature, low-pressure liquid refrigerant vaporizes into a low-temperature, low-pressure gaseous refrigerant. It is then drawn into the compressor (104) through the four-way valve (105) and compressed into high-pressure, high-temperature steam before being discharged into the condenser heat exchanger (106). In the condenser heat exchanger (106), the refrigerant is cooled by the cooling medium. The condensed liquid refrigerant is high-pressure and medium-temperature. After passing through the bidirectional drying filter (107) and the bidirectional liquid reservoir (109), it enters the first heat exchange refrigerant pipe (118). That is, after passing through the first heat exchange inlet solenoid valve (111) and the first heat exchange electronic expansion valve (112), it becomes a low-temperature and low-pressure liquid refrigerant. It re-enters the first heat exchange chamber (206) to absorb heat and vaporize, achieving a rapid cooling cycle. This cools the refrigerant in the first heat exchange chamber (206) to -4℃. The stirrer (204) at the bottom of the material chamber (205) of the precooling tank (200) rotates at 20±10 r / min, rapidly mixing the yak milk to increase the heat exchange speed and achieve rapid cooling of the yak milk.

[0020] Antifreeze cycle: The refrigerant circulates in the refrigeration components, the first heat exchange inlet solenoid valve (111), the first heat exchange electronic expansion valve (112), the first heat exchange refrigerant pipe (118), and the first heat exchange outlet solenoid valve (110). The low-temperature, low-pressure liquid refrigerant absorbs heat in the condenser heat exchanger (106) and vaporizes into a low-temperature, low-pressure gaseous refrigerant. It is then drawn into the compressor (104) through the four-way valve (105) and compressed into high-pressure, high-temperature steam before being discharged into the first heat exchange refrigerant pipe (118). It releases heat in the first heat exchange chamber (206) and condenses into a high-pressure medium-pressure gaseous refrigerant. The warm liquid refrigerant passes sequentially through the two-way liquid reservoir (109), the antifreeze electronic expansion valve (108), and the two-way drying filter (107), and then enters the refrigerant pipeline of the condenser heat exchanger (106). The high-pressure, medium-temperature liquid refrigerant is transformed into a low-temperature, low-pressure liquid refrigerant through the antifreeze electronic expansion valve (108), and then re-enters the condenser heat exchanger (106) to absorb heat and vaporize, achieving an antifreeze cycle; thus, the refrigerant in the first heat exchange chamber (206) is heated to 0°C. The stirrer (204) at the bottom of the material chamber (205) of the precooling tank (200) rotates at 20-30 r / min to quickly mix the yak milk and prevent some of the material from freezing due to uneven cooling;

[0021] Precise cooling cycle: The refrigerant circulates in the refrigeration components, the second heat exchange inlet solenoid valve (113), the second heat exchange electronic expansion valve (114), the second heat exchange refrigerant pipe (117), and the second heat exchange outlet solenoid valve (115). After absorbing heat in the second heat exchange chamber (207), the low-temperature, low-pressure liquid refrigerant vaporizes into a low-temperature, low-pressure gaseous refrigerant. It is then drawn into the compressor (104) through the four-way valve (105) and compressed into high-pressure, high-temperature steam before being discharged into the condenser heat exchanger (106). In the condenser heat exchanger (106), it is cooled by the cooling medium and condenses into a high-pressure, medium-temperature liquid refrigerant. It then passes through the bidirectional drying filter (…). 107) and the bidirectional liquid reservoir (109), then enter the second heat exchange refrigerant pipe (117), that is, through the second heat exchange inlet solenoid valve (113) and the second heat exchange electronic expansion valve (114) it becomes a low temperature and low pressure liquid refrigerant, and re-enters the second heat exchange chamber (207) to absorb heat and vaporize, achieving a rapid cooling cycle; realizing the cooling of the phase change material in the second heat exchange chamber (207) to 0°C, its cooling capacity is indirectly exchanged with the yak milk in the material chamber (205) of the precooling tank (200) through the first heat exchange chamber (206), the stirrer (204) at the bottom of the material chamber (205) of the precooling tank (200) rotates at 5-15 r / min, gently stirring to avoid air bubbles from being mixed in;

[0022] Cold storage state: The refrigerant circulates in the refrigeration components, the second heat exchange inlet solenoid valve (113), the second heat exchange electronic expansion valve (114), the second heat exchange refrigerant pipe (117), and the second heat exchange outlet solenoid valve (115). After absorbing heat in the second heat exchange chamber (207), the low-temperature, low-pressure liquid refrigerant vaporizes into a low-temperature, low-pressure gaseous refrigerant. It is then drawn into the compressor (104) through the four-way valve (105) and compressed into high-pressure, high-temperature steam before being discharged into the condenser heat exchanger (106). In the condenser heat exchanger (106), it is cooled by the cooling medium and condenses into a high-pressure, medium-temperature liquid refrigerant. After passing through the bidirectional... The dryer filter (107) and the two-way liquid reservoir (109) then enter the second heat exchange refrigerant pipe (117), that is, through the second heat exchange inlet solenoid valve (113) and the second heat exchange electronic expansion valve (114), it becomes a low-temperature and low-pressure liquid refrigerant, and re-enters the second heat exchange chamber (207) to absorb heat and vaporize, achieving a rapid cooling cycle; thus, the phase change material in the second heat exchange chamber (207) is cooled to 0°C. During cold storage, its cold energy is stored in the second heat exchange chamber (207), and during refrigeration, its cold energy is indirectly heat-exchanged with the yak milk in the material chamber (205) of the precooling tank (200) through the first heat exchange chamber (206).

[0023] Preferably, the 0°C phase change material is selected from an ice-water mixture.

[0024] On the other hand, the present invention also provides a control method for the above-mentioned rapid pre-cooling and antifreeze device for yak milk production areas, which includes the following steps:

[0025] S0: After startup, the user first selects the mode: rapid pre-cooling mode or cold storage mode, and sets the highest temperature t0h and the lowest temperature t0l for yak milk pre-cooling, where 6℃ > t0h > t0l > 0℃.

[0026] S1: The controller (102) determines whether it is a rapid pre-cooling mode. If so, it directly executes step S3. If not, it is a cold storage refrigeration mode and performs step S2.

[0027] S2: The real-time temperature T2 of the second heat exchange chamber (207) is obtained by the sensor assembly and the controller (102) determines whether T2 > 0. If yes, proceed to step S2-1; otherwise, return to step S1.

[0028] S2-1: The controller (102) controls the start of the cold storage and refrigeration state cycle. The refrigerant circulates in the refrigeration component, the second heat exchange inlet solenoid valve (113), the second heat exchange electronic expansion valve (114), the second heat exchange refrigerant pipe (117), and the second heat exchange outlet solenoid valve (115) to cool down the phase change material in the second heat exchange chamber (207) and continue to step S2-2.

[0029] S2-2: The sensor assembly obtains the real-time temperature T2 of the second heat exchange chamber (207) and the controller (102) determines whether T2≤0. If yes, proceed to step S2-3; otherwise, return to step S2-1.

[0030] S2-3: The controller (102) controls the cessation of the cold storage and refrigeration state cycle and returns to step S1;

[0031] S3: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber (205) and the controller (102) determines whether T0 ≥ 6℃. If yes, proceed to step S3-1; otherwise, proceed to step S4.

[0032] S3-1: The controller (102) controls the start of the rapid cooling state cycle, and the refrigerant circulates in the refrigeration component, the first heat exchange inlet solenoid valve (111), the first heat exchange electronic expansion valve (112), the first heat exchange refrigerant pipe (118), and the first heat exchange outlet solenoid valve (110) to achieve rapid cooling of the refrigerant in the first heat exchange chamber (206) and continue to step S3-2;

[0033] S3-2: The sensor assembly obtains the real-time temperature T1 of the first heat exchange chamber (206) and the controller (102) determines whether T1 ≤ -4℃. If yes, proceed to step S3-3; otherwise, return to step S3-1.

[0034] S3-3: The controller (102) controls the cessation of the rapid cooling cycle and returns to step S3;

[0035] S4: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber (205) and the real-time temperature T1 of the first heat exchange chamber (206), and the controller (102) determines whether T0 ≤ 4℃ or t0h and T1 < 0℃. If so, proceed to step S4-1; otherwise, proceed to step S5.

[0036] S4-1: The controller (102) controls the start of the antifreeze state cycle, and the refrigerant circulates in the refrigeration component, the first heat exchange inlet solenoid valve (111), the first heat exchange electronic expansion valve (112), the first heat exchange refrigerant pipe (118), and the first heat exchange outlet solenoid valve (110) to achieve rapid heating of the refrigerant in the first heat exchange chamber (206) and continue to step S4-2;

[0037] S4-2: The sensor assembly obtains the real-time temperature T1 of the first heat exchange chamber (206) and the controller (102) determines whether T1 ≥ 0℃. If yes, proceed to step S4-3; otherwise, return to step S4-1.

[0038] S4-3: The controller (102) controls the stop of the antifreeze state cycle and returns to step S4;

[0039] S5: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber (205) and the real-time temperature T2 of the second heat exchange chamber (207), and the controller (102) determines whether T0≥t0l and T2>0℃. If so, proceed to step S5-1; otherwise, proceed to step S6.

[0040] S5-1: The controller (102) controls the start of the precise cooling state cycle, and the refrigerant circulates in the refrigeration component, the second heat exchange inlet solenoid valve (113), the second heat exchange electronic expansion valve (114), the second heat exchange refrigerant pipe (117), and the second heat exchange outlet solenoid valve (115) to achieve cooling of the phase change material in the second heat exchange chamber (207), and continues to step S5-2;

[0041] S5-2: The sensor assembly obtains the real-time temperature T2 of the second heat exchange chamber (207) and the controller (102) determines whether T2 ≤ 0℃. If yes, proceed to step S5-3; otherwise, return to step S5-1.

[0042] S5-3: The controller (102) controls the stop of the precise cooling state cycle and continues to step S5-4;

[0043] S5-4: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber (205), and the controller (102) determines whether T0 ≤ t0l. If yes, proceed to step S6; otherwise, return to step S5-1.

[0044] S6: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber (205), and the controller (102) determines whether t0l≤T0≤t0h. If yes, proceed to step S6-1; otherwise, return to step S4.

[0045] S6-1: The controller (102) controls the exit of the rapid pre-cooling mode and returns to step S0.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] This invention provides a rapid pre-cooling and antifreeze device for yak milk at its production site and its control method. The pre-cooling tank is equipped with two jacketed cavities, namely a first heat exchange cavity and a second heat exchange cavity. Food-grade propylene glycol aqueous solution and a 0°C phase change material (such as an ice-water mixture) are used as the cold energy transfer medium, respectively, forming a two-stage gradient heat exchange structure for "rapid cooling + precise cooling" of the yak milk. The first heat exchange cavity is heated by a high-pressure, high-temperature refrigerant entering the first heat exchange refrigerant pipe, and the second heat exchange cavity uses a 0°C phase change material (ice-water mixture) with constant-temperature heat exchange characteristics, achieving dual-cavity temperature control and dual antifreeze. The primary function of the first heat exchange cavity is rapid cooling. However, when the real-time temperature of the yak milk in the material cavity, T0, is ≤4°C or lower than the set maximum pre-cooling temperature t0h, and the real-time temperature of the first heat exchange cavity, T1, is <0°C, reverse heating is achieved through the refrigerant to prevent the milk from freezing. This is a technical feature not found in existing technologies. Compared to traditional single-layer jacketed tank heat exchangers, the core advantages of this dual-medium dual-cavity design can be seen in its heat exchange efficiency, freeze protection, and adaptability to local energy consumption.

[0048] Staged heat exchange enhances cooling efficiency: The food-grade propylene glycol aqueous solution in the first heat exchange chamber can be precisely controlled to -4℃ (with in-tank magnetic stirring), utilizing the large temperature difference to drive rapid pre-cooling of yak milk from room temperature to 6℃, significantly shortening the initial cooling time; the 0℃ ice-water mixture in the second heat exchange chamber then carries out the subsequent cryogenic process, steadily reducing the yak milk from 6℃ to 0℃ or the minimum set temperature for yak milk pre-cooling. This two-stage heat exchange avoids the localized overcooling problem of single-medium low-temperature heat exchange and, through a "fast first, stable later" gradient design, improves pre-cooling efficiency, adapting to the large-scale, short-time yak milk pre-processing needs at the production site, and reducing the risk of raw milk spoilage due to stagnation at room temperature.

[0049] Dual-cavity temperature control and dual antifreeze design: Multiple distributed temperature sensors are installed inside the pre-cooling tank. When the real-time temperature of the yak milk in the material cavity drops to 6℃ and the temperature of the food-grade propylene glycol aqueous solution in the first heat exchange cavity is below 0℃, the device automatically enters an antifreeze cycle. High-pressure, high-temperature refrigerant is introduced into the refrigerant pipe of the first heat exchange cavity to reverse-heat the propylene glycol aqueous solution, quickly raising its temperature back above 0℃ and preventing the yak milk from becoming too cold due to continuous cooling by the low-temperature refrigerant. The second heat exchange cavity is filled with 0℃ phase change material (ice-water mixture), which utilizes the latent heat of phase change to maintain a constant temperature of 0℃ during the heat exchange process, preventing the risk of localized freezing from the source. This dual protection design of "reverse heating and temperature control + phase change constant temperature protection" precisely solves the technical contradiction of traditional single-layer heat exchangers where "rapid cooling leads to easy freezing, while antifreeze protection results in low efficiency." It effectively avoids damage to the cell walls caused by crystallization due to excessively low temperatures, maximizing the preservation of the original nutrients and flavor of the yak milk.

[0050] High adaptability to local energy consumption: The rapid precooling and antifreeze device for yak milk production integrates a double-layered cavity precooling tank into a single precooling tank, eliminating the need for additional heat exchange equipment. Its compact structure and small footprint allow for direct deployment on-site at pastures or flexible inter-pasture transport via a small power chassis. In line with the increasing adoption of solar photovoltaic systems in production areas, the device supports dual power inputs: it can connect to the 220V residential power grid or the 220V AC output from the local solar photovoltaic system. The 0℃ ice-water mixture in the second heat exchange chamber serves as a phase change energy storage medium. During peak photovoltaic periods, the device can enter a cold storage cycle, prioritizing the use of photovoltaic power to generate the ice-water mixture for cold storage, thus improving yak milk precooling efficiency and reducing the load on the refrigeration unit during rapid cooling cycles. Through its integrated design, utilizing a phase change energy storage medium, and reducing operating energy consumption, the rapid precooling and antifreeze device for yak milk production is suitable for remote pastoral areas with abundant photovoltaic resources, significantly controlling production costs. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the overall structure of a rapid pre-cooling and antifreeze device for yak milk production areas, provided in an embodiment of the present invention.

[0052] Figure 2 This is a schematic diagram of the structure of the first heat exchange cavity and the second heat exchange cavity provided in an embodiment of the present invention.

[0053] Figure 3 This is a schematic diagram of the structure of the refrigeration component and the heat exchange component provided in an embodiment of the present invention.

[0054] Figure 4 A flowchart illustrating the control method of the yak milk rapid pre-cooling and antifreeze device provided in this embodiment of the invention.

[0055] In the picture:

[0056] 100-Main unit chassis, 101-Condenser fan, 102-Controller, 103-Support, 104-Compressor, 105-Four-way valve, 106-Condenser heat exchanger, 107-Two-way dryer filter, 108-Anti-freeze electronic expansion valve, 109-Two-way liquid receiver, 110-First heat exchange outlet solenoid valve, 111-First heat exchange inlet solenoid valve, 112-First heat exchange electronic expansion valve, 113-Second heat exchange inlet solenoid valve 114-Second heat exchange electronic expansion valve, 115-Second heat exchange outlet solenoid valve, 116-Second heat exchange check valve, 117-Second heat exchange refrigerant pipe, 118-First heat exchange refrigerant pipe, 119-Gas-liquid separator, 200-Precooling tank, 201-Tank body, 202-Inlet, 203-Outlet, 204-Agitator, 205-Material chamber, 206-First heat exchange chamber, 207-Second heat exchange chamber, 208-Mounting base. Detailed Implementation

[0057] The invention provides a rapid pre-cooling and antifreeze device for yak milk production and its control method. The pre-cooling tank is equipped with two jacketed cavities, namely a first heat exchange cavity and a second heat exchange cavity. Food-grade propylene glycol aqueous solution and 0℃ phase change material (ice-water mixture) are used as the cold energy transfer medium, respectively, forming a two-stage gradient heat exchange structure of "rapid cooling + precise cooling" for yak milk. The reverse heating and temperature control method is adopted. The first heat exchange cavity is heated by high-pressure high-temperature refrigerant entering the first heat exchange refrigerant pipe, and the constant temperature heat exchange characteristics of the 0℃ phase change material (ice-water mixture) in the second heat exchange cavity are utilized to achieve dual-cavity temperature control and dual antifreeze.

[0058] The present invention will now be described in detail with reference to embodiments and accompanying drawings. However, it should be understood that the embodiments and drawings are for illustrative purposes only and do not constitute any limitation on the scope of protection of the present invention. All reasonable modifications and combinations included within the inventive spirit of the present invention fall within the scope of protection of the present invention.

[0059] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "front," and "rear," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication of two components. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0060] The present invention will be further described below with reference to the accompanying drawings.

[0061] Example 1

[0062] like Figure 1 As shown, this embodiment provides a rapid pre-cooling and antifreeze device for yak milk production, hereinafter referred to as the pre-cooling device, which includes a main unit 100, a controller 102, a pre-cooling tank 200, a hollow support 103, a refrigeration component, a heat exchange component, and a sensor component.

[0063] The sensor assembly includes multiple distributed temperature sensors installed inside the tank body 201 of the precooling tank 200. The temperature sensors are used to collect temperature signals from various locations within the material chamber 205, the first heat exchange chamber 206, and the second heat exchange chamber 207 of the tank body 201. The controller 102 is installed in the upper space inside the main unit 100. The controller 102 is electrically connected to both the refrigeration assembly and the sensor assembly. It is used to receive the temperature signals collected by the sensor assembly in real time, analyze and judge them, and then control the working status of the precooling device. The controller 102 is equipped with a display screen and operation panel for starting and stopping the precooling device and setting the temperature. The mounting base 208 of the precooling tank 200 is installed on the support 103. The material chamber 205 of the tank body 201 has an inlet 202 directly above it and an outlet 203 on its lower side. The main unit 100 has a power input port that can be connected to a 220V household power grid or a 220V AC power output from a solar photovoltaic system at the production site.

[0064] like Figure 2 The cavity inside the precooling tank 200 is the material cavity 205, which is used to hold the yak milk to be precooled. Two jacketed cavities are set inside the tank body 201 of the precooling tank 200 outside the material cavity 205: a first heat exchange cavity 206 and a second heat exchange cavity 207, which respectively use food-grade propylene glycol aqueous solution and 0℃ phase change material (ice-water mixture) as the cooling medium. A first heat exchange refrigerant pipe 118 and a second heat exchange refrigerant pipe 117 are installed in the first heat exchange cavity 206 and the second heat exchange cavity 207, respectively. The food-grade propylene glycol aqueous solution in the first heat exchange cavity 206 can be precisely controlled to - At 4℃, the large temperature difference driving force enables rapid pre-cooling of yak milk from room temperature to 6℃, significantly shortening the initial cooling time. The 0℃ ice-water mixture in the second heat exchange chamber 207 then undertakes the subsequent deep-cryogenic process, steadily reducing the yak milk from 6℃ to 0℃ or the minimum set temperature for yak milk pre-cooling. A stirrer 204 is installed in the center of the bottom of the pre-cooling tank 200, employing a non-contact structure with external magnetic drive and an internal stir bar (this is conventional technology and will not be described in detail here). The drive unit of the stirrer 204 is externally installed in the inner cavity of the bottom support 103 of the pre-cooling tank 200. The tank body 201 is made of 304 stainless steel or 316 stainless steel, and the interlayer between the first heat exchange chamber 206 and the second heat exchange chamber 207 is made of stainless steel for isolation.

[0065] like Figure 3 The refrigeration components are installed inside the main unit casing 100. The refrigeration components include: a four-way valve 105, a compressor 104, a gas-liquid separator 119, a two-way liquid receiver 109, an antifreeze electronic expansion valve 108, a two-way dryer filter 107, a condenser heat exchanger 106, a condenser fan 101, and refrigerant pipes between them.

[0066] The heat exchange assembly includes: a first heat exchange inlet solenoid valve 111, a first heat exchange electronic expansion valve 112, a first heat exchange refrigerant pipe 118, a first heat exchange outlet solenoid valve 110, a second heat exchange inlet solenoid valve 113, a second heat exchange electronic expansion valve 114, a second heat exchange refrigerant pipe 117, a second heat exchange check valve 116, a second heat exchange outlet solenoid valve 115, and refrigerant pipes between them. The first heat exchange refrigerant pipe 118 and the second heat exchange refrigerant pipe 117 are respectively installed in the first heat exchange chamber 206 and the second heat exchange chamber 207 of the precooling tank 200. The remaining components of the heat exchange assembly and the refrigerant pipes between them are installed in the inner cavity of the support 103. The condenser fan 101 is used to accelerate the airflow on the surface of the condenser heat exchanger 106, forcibly removing the heat released by the refrigerant in the condenser pipes or providing a heat source for refrigerant vaporization.

[0067] The refrigerant is transported to various components of the refrigeration system and the heat exchange system via refrigerant pipelines. Specifically: a four-way valve 105 is used to switch the flow direction of the refrigerant. The four-way valve 105 has four inlets and outlets connected via refrigerant pipelines to the compressor 104, the gas-liquid separator 119, the bidirectional liquid receiver 109, and the first and second heat exchange outlet solenoid valves 110 and 115 of the heat exchange system, respectively. The compressor 104 compresses the gaseous refrigerant, increasing its pressure and temperature, and propelling the refrigerant through the rapid pre-cooling and antifreeze device. The compressor 104 is connected via refrigerant pipelines to the bidirectional liquid receiver 109, the four-way valve 105, and the gas-liquid separator 119, respectively. The gas-liquid separator 119 separates incompletely evaporated liquid refrigerant from the refrigerant pipeline. The gas-liquid separator 119 is connected via refrigerant pipelines to the four-way valve 105 and the compressor 104, respectively. The bidirectional liquid receiver 109 stores condenser heat. The refrigerant liquid in the heat exchanger 106 or the first heat exchange refrigerant pipe 118 is used to achieve gas-liquid separation, drying and filtration functions. One end of the two-way liquid receiver 109 is connected to the antifreeze electronic expansion valve 108, the two-way dryer filter 107 and the condenser heat exchanger 106 in sequence through the refrigerant pipe. The other end of the two-way liquid receiver 109 is divided into two paths through the refrigerant pipe. One path is connected to the first heat exchange inlet solenoid valve 111, the first heat exchange electronic expansion valve 112, the first heat exchange refrigerant pipe 118 and the first heat exchange outlet solenoid valve 110 through the refrigerant pipe. The other path is connected to the second heat exchange inlet solenoid valve 113, the second heat exchange electronic expansion valve 114, the second heat exchange refrigerant pipe 117, the second heat exchange check valve 116 and the second heat exchange outlet solenoid valve 115 through the refrigerant pipe.

[0068] The precooling unit operates in four states: rapid cooling cycle, antifreeze cycle, precise cooling cycle, and cold storage cycle. The working processes of the refrigeration components, heat exchange components, and other parts under different cycle states are as follows:

[0069] Rapid cooling cycle: The refrigerant circulates in the refrigeration components, the first heat exchange inlet solenoid valve 111, the first heat exchange electronic expansion valve 112, the first heat exchange refrigerant pipe 118, and the first heat exchange outlet solenoid valve 110. After absorbing heat in the first heat exchange chamber 206, the low-temperature, low-pressure liquid refrigerant vaporizes into a low-temperature, low-pressure gaseous refrigerant. It is then drawn into the compressor 104 through the four-way valve 105 and compressed into high-pressure, high-temperature vapor before being discharged into the condenser heat exchanger 106. In the condenser heat exchanger 106, it is cooled by the cooling medium and condenses into a high-pressure, medium-temperature liquid refrigerant. After passing through the bidirectional dryer filter 107 and the bidirectional liquid receiver 109, it enters the first heat exchange refrigerant pipe 118, which then passes through the first heat exchange inlet solenoid valve 111 and the first heat exchange electronic expansion valve 112 to become a low-temperature, low-pressure liquid refrigerant. It then re-enters the first heat exchange chamber 206 to absorb heat and vaporize, thus achieving a rapid cooling cycle. The refrigerant in the first heat exchange chamber 206 is cooled to -4℃. The stirrer 204 at the bottom of the material chamber 205 in the precooling tank 200 rotates at 20±10 r / min, which quickly mixes the yak milk and increases the heat exchange speed to achieve rapid cooling of the yak milk.

[0070] Anti-freeze cycle: The refrigerant circulates in the refrigeration components, the first heat exchange inlet solenoid valve 111, the first heat exchange electronic expansion valve 112, the first heat exchange refrigerant pipe 118, and the first heat exchange outlet solenoid valve 110. The low-temperature, low-pressure liquid refrigerant absorbs heat in the condenser heat exchanger 106 and vaporizes into a low-temperature, low-pressure gaseous refrigerant. It is then drawn into the compressor 104 through the four-way valve 105 and compressed into a high-pressure, high-temperature vapor before being discharged into the first heat exchange refrigerant pipe 118. It releases heat in the first heat exchange chamber 206 and condenses into a high-pressure, medium-temperature liquid refrigerant. This liquid refrigerant passes sequentially through the bidirectional liquid receiver 109, the anti-freeze electronic expansion valve 108, and the bidirectional dryer filter 107 before entering the refrigerant line of the condenser heat exchanger 106. The high-pressure, medium-temperature liquid refrigerant is then transformed into a low-temperature, low-pressure liquid refrigerant through the anti-freeze electronic expansion valve 108 and re-enters the condenser heat exchanger 106 to absorb heat and vaporize, thus achieving the anti-freeze cycle. The refrigerant in the first heat exchange chamber 206 is heated to 0°C. The stirrer 204 at the bottom of the material chamber 205 in the precooling tank 200 rotates at 20~30 r / min to quickly mix the yak milk and prevent some of the material from freezing due to uneven cooling.

[0071] Precise cooling cycle: The refrigerant circulates in the refrigeration components, the second heat exchange inlet solenoid valve 113, the second heat exchange electronic expansion valve 114, the second heat exchange refrigerant pipe 117, and the second heat exchange outlet solenoid valve 115. After absorbing heat in the second heat exchange chamber 207, the low-temperature, low-pressure liquid refrigerant vaporizes into a low-temperature, low-pressure gaseous refrigerant. It is then drawn into the compressor 104 through the four-way valve 105 and compressed into high-pressure, high-temperature vapor before being discharged into the condenser heat exchanger 106. In the condenser heat exchanger 106, it is cooled by the cooling medium and condenses into a high-pressure, medium-temperature liquid refrigerant. After passing through the bidirectional dryer filter 107 and the bidirectional liquid receiver 109, it enters the second heat exchange refrigerant pipe 117, which then passes through the second heat exchange inlet solenoid valve 113 and the second heat exchange electronic expansion valve 114 to become a low-temperature, low-pressure liquid refrigerant. It then re-enters the second heat exchange chamber 207 to absorb heat and vaporize, achieving a rapid cooling cycle. The phase change material in the second heat exchange chamber 207 is cooled to 0°C. Its cooling capacity is indirectly exchanged with the yak milk in the material chamber 205 of the precooling tank 200 through the first heat exchange chamber 206. The stirrer 204 at the bottom of the material chamber 205 of the precooling tank 200 rotates at a speed of 5~15 r / min to gently stir and avoid the mixing of air bubbles.

[0072] In the cold storage state: the refrigerant circulates in the refrigeration components, the second heat exchange inlet solenoid valve 113, the second heat exchange electronic expansion valve 114, the second heat exchange refrigerant pipe 117, and the second heat exchange outlet solenoid valve 115. After absorbing heat in the second heat exchange chamber 207, the low-temperature, low-pressure liquid refrigerant vaporizes into a low-temperature, low-pressure gaseous refrigerant. It is then drawn into the compressor 104 through the four-way valve 105 and compressed into high-pressure, high-temperature vapor before being discharged into the condenser heat exchanger 106. In the condenser heat exchanger 106, it is cooled by the cooling medium and condenses into a high-pressure, medium-temperature liquid refrigerant. After passing through the bidirectional dryer filter 107 and the bidirectional liquid receiver 109, it enters the second heat exchange refrigerant pipe 117, that is, it becomes a low-temperature, low-pressure liquid refrigerant through the second heat exchange inlet solenoid valve 113 and the second heat exchange electronic expansion valve 114, and re-enters the second heat exchange chamber 207 to absorb heat and vaporize, achieving a rapid cooling cycle. The phase change material in the second heat exchange chamber 207 is cooled to 0°C. During cold storage, its cold energy is stored in the second heat exchange chamber 207. During refrigeration, its cold energy is indirectly exchanged with the yak milk in the material chamber 205 of the pre-cooling tank 200 through the first heat exchange chamber 206.

[0073] Figure 4 A flowchart of a rapid pre-cooling and antifreezing control method for the yak milk origin rapid pre-cooling and antifreezing device provided in this embodiment is shown. The control method includes the following steps:

[0074] S0: After startup, the user first selects the mode: rapid pre-cooling mode or cold storage mode, and sets the highest temperature t0h and the lowest temperature t0l for yak milk pre-cooling, where 6℃ > t0h > t0l > 0℃.

[0075] S1: Controller 102 determines whether it is a rapid pre-cooling mode. If yes, it directly executes step S3. If no, it is a cold storage refrigeration mode and proceeds to step S2.

[0076] S2: The real-time temperature T2 of the second heat exchange chamber 207 is obtained by the sensor assembly and the controller 102 determines whether T2 > 0. If yes, proceed to step S2-1; otherwise, return to step S1.

[0077] S2-1: Controller 102 controls the start of the cold storage and refrigeration state cycle. The refrigerant circulates in the refrigeration components, the second heat exchange inlet solenoid valve 113, the second heat exchange electronic expansion valve 114, the second heat exchange refrigerant pipe 117, and the second heat exchange outlet solenoid valve 115 to cool down the phase change material in the second heat exchange chamber 207 and continue to step S2-2.

[0078] S2-2: The real-time temperature T2 of the second heat exchange chamber 207 is obtained by the sensor assembly and the controller 102 determines whether T2≤0. If yes, proceed to step S2-3; otherwise, return to step S2-1.

[0079] S2-3: Controller 102 stops the cold storage and refrigeration state cycle and returns to step S1;

[0080] S3: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber 205 and the controller 102 determines whether T0 ≥ 6℃. If yes, proceed to step S3-1; otherwise, proceed to step S4.

[0081] S3-1: Controller 102 controls the start of the rapid cooling cycle. The refrigerant circulates in the refrigeration components, the first heat exchange inlet solenoid valve 111, the first heat exchange electronic expansion valve 112, the first heat exchange refrigerant pipe 118, and the first heat exchange outlet solenoid valve 110 to achieve rapid cooling of the refrigerant in the first heat exchange chamber 206, and then continues to step S3-2.

[0082] S3-2: The real-time temperature T1 of the first heat exchange chamber 206 is obtained by the sensor assembly and the controller 102 determines whether T1 ≤ -4℃. If yes, proceed to step S3-3; otherwise, return to step S3-1.

[0083] S3-3: Controller 102 stops the rapid cooling cycle and returns to step S3;

[0084] S4: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber 205 and the real-time temperature T1 of the first heat exchange chamber 206, and the controller 102 determines whether T0 ≤ 4℃ or t0h, and T1 < 0℃. If so, proceed to step S4-1; otherwise, proceed to step S5.

[0085] S4-1: The controller initiates the antifreeze cycle, and the refrigerant circulates in the refrigeration components, the first heat exchange inlet solenoid valve 111, the first heat exchange electronic expansion valve 112, the first heat exchange refrigerant pipe 118, and the first heat exchange outlet solenoid valve 110 to achieve rapid heating of the refrigerant in the first heat exchange chamber 206, and then continues to step S4-2.

[0086] S4-2: The real-time temperature T1 of the first heat exchange chamber 206 is obtained by the sensor assembly and the controller 102 determines whether T1≥0℃. If yes, proceed to step S4-3; otherwise, return to step S4-1.

[0087] S4-3: Controller 102 stops the antifreeze cycle and returns to step S4;

[0088] S5: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber 205 and the real-time temperature T2 of the second heat exchange chamber 207, and the controller 102 determines whether T0≥t0l and T2>0℃. If yes, proceed to step S5-1; otherwise, proceed to step S6.

[0089] S5-1: Controller 102 controls the start of precise cooling cycle. The refrigerant circulates in the refrigeration components, the second heat exchange inlet solenoid valve 113, the second heat exchange electronic expansion valve 114, the second heat exchange refrigerant pipe 117, and the second heat exchange outlet solenoid valve 115 to cool the phase change material in the second heat exchange chamber 207 and continue to step S5-2.

[0090] S5-2: The real-time temperature T2 of the second heat exchange chamber 207 is obtained by the sensor assembly and the controller 102 determines whether T2≤0. If yes, proceed to step S5-3; otherwise, return to step S5-1.

[0091] S5-3: Controller 102 stops the precise cooling state cycle and continues to step S5-4;

[0092] S5-4: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber 205, and the controller 102 determines whether T0≤t0l. If yes, proceed to step S6; otherwise, return to step S5-1.

[0093] S6: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber 205, and the controller 102 determines whether t0l≤T0≤t0h. If yes, proceed to step S6-1; otherwise, return to step S4.

[0094] S6-1: The controller exits the rapid pre-cooling mode and returns to step S0.

[0095] The above embodiments are merely preferred embodiments of the present invention, and the scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A rapid pre-cooling and antifreeze device for yak milk at its production site, characterized in that: include: The main unit (100) and the precooling tank (200) are mounted on the support (103). The tank body (201) of the precooling tank (200) is provided with a material chamber (205). The material chamber (205) is provided with a first heat exchange chamber (206) and a second heat exchange chamber (207) from the inside to the outside. The material chamber (205) is used to hold yak milk to be precooled. The first heat exchange chamber (206) and the second heat exchange chamber (207) are respectively filled with food-grade propylene glycol aqueous solution and 0℃ phase change material as cold energy transfer medium. The heat exchange assembly includes a first heat exchange refrigerant pipe (118) disposed in the first heat exchange chamber (206) and a second heat exchange refrigerant pipe (117) disposed in the second heat exchange chamber (207). The controller (102) is electrically connected to the refrigeration component, the heat exchange component, and the sensor component, respectively. The sensor component includes multiple distributed temperature sensors for collecting temperature signals in the material chamber (205), the first heat exchange chamber (206), and the second heat exchange chamber (207), respectively. The controller (102) and the refrigeration component are located inside the main unit housing (100). The refrigeration component and the heat exchange component are connected through a refrigerant pipeline. The controller (102) controls the refrigeration component to cool and transport the refrigerant according to the temperature signal returned by the sensor component. By rapidly pre-cooling or heating the first heat exchange chamber (206) and precisely cooling the second heat exchange chamber (207), the yak milk in the material chamber (205) is rapidly pre-cooled, precisely cooled, and double-frozen. When the sensor assembly obtains that the real-time temperature of the yak milk in the material chamber (205) is ≤4℃ or less than the set maximum temperature for pre-cooling the yak milk, and the real-time temperature of the first heat exchange chamber (206) is <0℃, the controller (102) controls the first heat exchange refrigerant pipe (118) of the heat exchange assembly to heat the first heat exchange chamber (206) according to the temperature signal returned by the sensor assembly, and utilizes the constant temperature heat exchange characteristics of the 0℃ phase change material of the second heat exchange chamber (207) to achieve dual-chamber temperature control and dual antifreeze.

2. The rapid pre-cooling and antifreeze device for yak milk at its origin according to claim 1, characterized in that: The first heat exchange refrigerant pipe (118) is provided with a first heat exchange inlet solenoid valve (111) at the inlet end and a first heat exchange electronic expansion valve (112) and a first heat exchange outlet solenoid valve (110) at the outlet end. The inlet end of the second heat exchange refrigerant pipe (117) is provided with a second heat exchange inlet solenoid valve (113) and a second heat exchange electronic expansion valve (114), and the outlet end is provided with a second heat exchange check valve (116) and a second heat exchange outlet solenoid valve (115). The remaining components of the heat exchange assembly, except for the first and second heat exchange refrigerant pipes, and the refrigerant pipes between them are located in the support (103).

3. The rapid pre-cooling and antifreeze device for yak milk at its origin according to claim 2, characterized in that: The refrigeration assembly includes a four-way valve (105), which is used to switch the flow direction of the refrigerant. The four inlets and outlets of the four-way valve (105) are connected to the compressor (104), the gas-liquid separator (119), the two-way liquid receiver (109), the first heat exchange outlet solenoid valve (110), and the second heat exchange outlet solenoid valve (115) respectively through refrigerant pipes. The compressor (104) compresses the gaseous refrigerant, increases its pressure and temperature, and drives the refrigerant to circulate. The compressor (104) is connected to the two-way liquid receiver (109), the four-way valve (105), and the gas-liquid separator (119) respectively through refrigerant pipes. The gas-liquid separator (119) is used to separate the liquid refrigerant that has not been completely evaporated in the refrigerant pipe. The gas-liquid separator (119) is connected to the four-way valve (105) and the compressor (104) respectively through refrigerant pipes. The two-way liquid receiver (109) is used to store refrigerant. The refrigerant liquid in the condenser heat exchanger (106) or the first heat exchange refrigerant pipe (118) is used to achieve gas-liquid separation, drying and filtration. One end of the two-way liquid reservoir (109) is connected to the antifreeze electronic expansion valve (108), the two-way drying filter (107) and the condenser heat exchanger (106) in sequence through the refrigerant pipe. The other end of the two-way liquid reservoir (109) is divided into two paths through the refrigerant pipe. One path is connected to the first heat exchange inlet solenoid valve (111), the first heat exchange electronic expansion valve (112), the first heat exchange refrigerant pipe (118) and the first heat exchange outlet solenoid valve (110) through the refrigerant pipe. The other path is connected to the second heat exchange inlet solenoid valve (113), the second heat exchange electronic expansion valve (114), the second heat exchange refrigerant pipe (117), the second heat exchange check valve (116) and the second heat exchange outlet solenoid valve (115) through the refrigerant pipe.

4. The rapid pre-cooling and antifreeze device for yak milk at its origin according to claim 3, characterized in that: The controller (102) controls the refrigeration component to cool and transport the refrigerant based on the temperature signal returned by the sensor component. Cooling is achieved through the first and second heat exchange refrigerant pipes. The control modes include rapid cooling cycle, antifreeze cycle, precise cooling cycle, and cold storage cycle. The working process of the refrigeration component and the heat exchange component under different cycle states is as follows: Rapid cooling cycle: The refrigerant circulates in the refrigeration components, the first heat exchange inlet solenoid valve (111), the first heat exchange electronic expansion valve (112), the first heat exchange refrigerant pipe (118), and the first heat exchange outlet solenoid valve (110). After absorbing heat in the first heat exchange chamber (206), the low-temperature, low-pressure liquid refrigerant vaporizes into a low-temperature, low-pressure gaseous refrigerant. It is then drawn into the compressor (104) through the four-way valve (105) and compressed into high-pressure, high-temperature steam before being discharged into the condenser heat exchanger (106). In the condenser heat exchanger (106), the refrigerant is cooled by the cooling medium. The condensed liquid refrigerant is high-pressure and medium-temperature. After passing through the bidirectional drying filter (107) and the bidirectional liquid reservoir (109), it enters the first heat exchange refrigerant pipe (118). That is, after passing through the first heat exchange inlet solenoid valve (111) and the first heat exchange electronic expansion valve (112), it becomes a low-temperature and low-pressure liquid refrigerant. It re-enters the first heat exchange chamber (206) to absorb heat and vaporize, achieving a rapid cooling cycle. This cools the refrigerant in the first heat exchange chamber (206) to -4℃. The stirrer (204) at the bottom of the material chamber (205) of the precooling tank (200) rotates at 20±10 r / min, rapidly mixing the yak milk to increase the heat exchange speed and achieve rapid cooling of the yak milk. Antifreeze cycle: The refrigerant circulates in the refrigeration components, the first heat exchange inlet solenoid valve (111), the first heat exchange electronic expansion valve (112), the first heat exchange refrigerant pipe (118), and the first heat exchange outlet solenoid valve (110). The low-temperature, low-pressure liquid refrigerant absorbs heat in the condenser heat exchanger (106) and vaporizes into a low-temperature, low-pressure gaseous refrigerant. It is then drawn into the compressor (104) through the four-way valve (105) and compressed into high-pressure, high-temperature steam before being discharged into the first heat exchange refrigerant pipe (118). It releases heat in the first heat exchange chamber (206) and condenses into a high-pressure medium-pressure gaseous refrigerant. The warm liquid refrigerant passes sequentially through the two-way liquid reservoir (109), the antifreeze electronic expansion valve (108), and the two-way drying filter (107), and then enters the refrigerant pipeline of the condenser heat exchanger (106). The high-pressure, medium-temperature liquid refrigerant is transformed into a low-temperature, low-pressure liquid refrigerant through the antifreeze electronic expansion valve (108), and then re-enters the condenser heat exchanger (106) to absorb heat and vaporize, achieving an antifreeze cycle; thus, the refrigerant in the first heat exchange chamber (206) is heated to 0°C. The stirrer (204) at the bottom of the material chamber (205) of the precooling tank (200) rotates at 20-30 r / min to quickly mix the yak milk and prevent some of the material from freezing due to uneven cooling; Precise cooling cycle: The refrigerant circulates in the refrigeration components, the second heat exchange inlet solenoid valve (113), the second heat exchange electronic expansion valve (114), the second heat exchange refrigerant pipe (117), and the second heat exchange outlet solenoid valve (115). After absorbing heat in the second heat exchange chamber (207), the low-temperature, low-pressure liquid refrigerant vaporizes into a low-temperature, low-pressure gaseous refrigerant. It is then drawn into the compressor (104) through the four-way valve (105) and compressed into high-pressure, high-temperature steam before being discharged into the condenser heat exchanger (106). In the condenser heat exchanger (106), it is cooled by the cooling medium and condenses into a high-pressure, medium-temperature liquid refrigerant. It then passes through the bidirectional drying filter (…). 107) and the bidirectional liquid reservoir (109), then enter the second heat exchange refrigerant pipe (117), that is, through the second heat exchange inlet solenoid valve (113) and the second heat exchange electronic expansion valve (114) it becomes a low temperature and low pressure liquid refrigerant, and re-enters the second heat exchange chamber (207) to absorb heat and vaporize, achieving a rapid cooling cycle; realizing the cooling of the phase change material in the second heat exchange chamber (207) to 0°C, its cooling capacity is indirectly exchanged with the yak milk in the material chamber (205) of the precooling tank (200) through the first heat exchange chamber (206), the stirrer (204) at the bottom of the material chamber (205) of the precooling tank (200) rotates at 5-15 r / min, gently stirring to avoid air bubbles from being mixed in; Cold storage state: The refrigerant circulates in the refrigeration components, the second heat exchange inlet solenoid valve (113), the second heat exchange electronic expansion valve (114), the second heat exchange refrigerant pipe (117), and the second heat exchange outlet solenoid valve (115). After absorbing heat in the second heat exchange chamber (207), the low-temperature, low-pressure liquid refrigerant vaporizes into a low-temperature, low-pressure gaseous refrigerant. It is then drawn into the compressor (104) through the four-way valve (105) and compressed into high-pressure, high-temperature steam before being discharged into the condenser heat exchanger (106). In the condenser heat exchanger (106), it is cooled by the cooling medium and condenses into a high-pressure, medium-temperature liquid refrigerant. After passing through the bidirectional... The dryer filter (107) and the two-way liquid reservoir (109) then enter the second heat exchange refrigerant pipe (117), that is, through the second heat exchange inlet solenoid valve (113) and the second heat exchange electronic expansion valve (114), it becomes a low-temperature and low-pressure liquid refrigerant, and re-enters the second heat exchange chamber (207) to absorb heat and vaporize, achieving a rapid cooling cycle; thus, the phase change material in the second heat exchange chamber (207) is cooled to 0°C. During cold storage, its cold energy is stored in the second heat exchange chamber (207), and during refrigeration, its cold energy is indirectly heat-exchanged with the yak milk in the material chamber (205) of the precooling tank (200) through the first heat exchange chamber (206).

5. The rapid pre-cooling and antifreeze device for yak milk production areas according to any one of claims 1 to 4, characterized in that: The 0℃ phase change material is selected from an ice-water mixture.

6. A control method for the rapid pre-cooling and antifreeze device for yak milk at its origin according to claim 4, characterized in that: Includes the following steps: S0: After startup, the user first selects the mode: rapid pre-cooling mode or cold storage mode, and sets the highest temperature t0h and the lowest temperature t0l for yak milk pre-cooling, where 6℃>t0h>t0l>0℃; S1: The controller (102) determines whether it is a rapid pre-cooling mode. If so, it directly executes step S3. If not, it is a cold storage refrigeration mode and performs step S2. S2: The real-time temperature T2 of the second heat exchange chamber (207) is obtained by the sensor assembly and the controller (102) determines whether T2 > 0. If yes, proceed to step S2-1; otherwise, return to step S1. S2-1: The controller (102) controls the start of the cold storage and refrigeration state cycle. The refrigerant circulates in the refrigeration component, the second heat exchange inlet solenoid valve (113), the second heat exchange electronic expansion valve (114), the second heat exchange refrigerant pipe (117), and the second heat exchange outlet solenoid valve (115) to cool down the phase change material in the second heat exchange chamber (207) and continue to step S2-2. S2-2: The sensor assembly obtains the real-time temperature T2 of the second heat exchange chamber (207) and the controller (102) determines whether T2≤0. If yes, proceed to step S2-3; otherwise, return to step S2-1. S2-3: The controller (102) controls the cessation of the cold storage and refrigeration state cycle and returns to step S1; S3: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber (205) and the controller (102) determines whether T0 ≥ 6℃. If yes, proceed to step S3-1; otherwise, proceed to step S4. S3-1: The controller (102) controls the start of the rapid cooling state cycle, and the refrigerant circulates in the refrigeration component, the first heat exchange inlet solenoid valve (111), the first heat exchange electronic expansion valve (112), the first heat exchange refrigerant pipe (118), and the first heat exchange outlet solenoid valve (110) to achieve rapid cooling of the refrigerant in the first heat exchange chamber (206) and continue to step S3-2; S3-2: The sensor assembly obtains the real-time temperature T1 of the first heat exchange chamber (206) and the controller (102) determines whether T1 ≤ -4℃. If yes, proceed to step S3-3; otherwise, return to step S3-1. S3-3: The controller (102) controls the cessation of the rapid cooling cycle and returns to step S3; S4: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber (205) and the real-time temperature T1 of the first heat exchange chamber (206), and the controller (102) determines whether T0 ≤ 4℃ or t0h and T1 < 0℃. If so, proceed to step S4-1; otherwise, proceed to step S5. S4-1: The controller (102) controls the start of the antifreeze state cycle, and the refrigerant circulates in the refrigeration component, the first heat exchange inlet solenoid valve (111), the first heat exchange electronic expansion valve (112), the first heat exchange refrigerant pipe (118), and the first heat exchange outlet solenoid valve (110) to achieve rapid heating of the refrigerant in the first heat exchange chamber (206) and continue to step S4-2; S4-2: The sensor assembly obtains the real-time temperature T1 of the first heat exchange chamber (206) and the controller (102) determines whether T1 ≥ 0℃. If yes, proceed to step S4-3; otherwise, return to step S4-1. S4-3: The controller (102) controls the stop of the antifreeze state cycle and returns to step S4; S5: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber (205) and the real-time temperature T2 of the second heat exchange chamber (207), and the controller (102) determines whether T0≥t0l and T2>0℃. If so, proceed to step S5-1; otherwise, proceed to step S6. S5-1: The controller (102) controls the start of the precise cooling state cycle, and the refrigerant circulates in the refrigeration component, the second heat exchange inlet solenoid valve (113), the second heat exchange electronic expansion valve (114), the second heat exchange refrigerant pipe (117), and the second heat exchange outlet solenoid valve (115) to achieve cooling of the phase change material in the second heat exchange chamber (207), and continues to step S5-2; S5-2: The sensor assembly obtains the real-time temperature T2 of the second heat exchange chamber (207) and the controller (102) determines whether T2 ≤ 0℃. If yes, proceed to step S5-3; otherwise, return to step S5-1. S5-3: The controller (102) controls the stop of the precise cooling state cycle and continues to step S5-4; S5-4: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber (205), and the controller (102) determines whether T0 ≤ t0l. If yes, proceed to step S6; otherwise, return to step S5-1. S6: The sensor assembly obtains the real-time temperature T0 of the yak milk in the material chamber (205), and the controller (102) determines whether t0l≤T0≤t0h. If yes, proceed to step S6-1; otherwise, return to step S4. S6-1: The controller (102) controls the exit of the rapid pre-cooling mode and returns to step S0.

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