A refrigeration system and control method with refrigerant redundancy adjustment function

Abstract

The application provides a refrigeration system and a control method with a refrigerant redundancy adjustment function, which comprises a fluorine pump, a liquid storage tank, an evaporator and a balance pipe. The liquid storage tank comprises an outer cylinder and an inner cylinder. The inner cylinder is located at the inner periphery of the outer cylinder, and a first communication hole is arranged on the cylinder wall of the inner cylinder to enable the inner part of the inner cylinder to communicate with the inner part of the outer cylinder. The fluorine pump is communicated between the inner part of the outer cylinder and the evaporator. One end of the balance pipe is communicated to the inner upper end of the inner cylinder, and the other end of the balance pipe is communicated to the outlet end of the evaporator. In the fluorine pump mode, the balance pipe can introduce fluid from the outlet end of the evaporator to the inner part of the inner cylinder, so that at least part of the liquid in the inner cylinder can be pressed into the outer cylinder through the first communication hole. The application further comprises a compressor and an oil return assembly. The oil return assembly can recover the oil-containing mixture in the liquid storage tank and can deliver the separated oil to the compressor. According to the application, the cavitation problem in the fluorine pump refrigeration mode can be solved, and the problem of poor oil return when the compressor starts can also be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of refrigeration technology, in particular to a refrigeration system and control method with refrigerant redundancy adjustment function. BACKGROUND

[0002] With the large application of 4G and the gradual popularization of 5G, the heat dissipation of various data processing equipment is getting larger and larger, and the data center has higher and higher requirements for the refrigerating capacity and energy saving of air conditioning equipment.

[0003] Using the outdoor natural cold source in the transition season and cold winter to cool the data center can greatly reduce the operating cost of the air conditioning equipment. Commonly, a fluorine pump air conditioner is used, and in winter, the fluorine pump mode is started and the operation of the compressor is stopped to realize heat pipe refrigeration operation by driving the refrigerant by the fluorine pump, greatly reducing the operating cost of the equipment.

[0004] The fluorine pump compression refrigeration system belongs to a composite system, and the fluorine pump heat pipe system and the compression refrigeration system share an evaporator and a condenser, as well as some shared refrigerant pipelines, system components, etc.

[0005] Since the heat load of the data center fluctuates with the user usage and seasonal time, more and more computer room air conditioners now use frequency conversion technology to cope with the heat load fluctuation of the data center to ensure the constant temperature and humidity demand of the data center. However, the change of the frequency of the compressor of the refrigeration system will cause the change of the optimal refrigerant circulation amount, and generally the higher the frequency, the greater the required refrigerant circulation amount. If the optimal refrigerant filling amount under 100% load is ensured during the design and development of the refrigeration system, the optimal refrigerant filling amount under 75% or 50% or other low frequency operation conditions is relatively small, so there may be liquid accumulation in the refrigerant inside the unit under low frequency working conditions, which is not conducive to heat exchange.

[0006] Considering the liquid level requirement of the fluorine pump suction inlet under the fluorine pump mode, the required refrigerant filling amount under the fluorine pump mode is also relatively large, so the fluorine pump compression refrigeration system may form a refrigerant liquid retention condition under actual operation conditions, and it is necessary to consider migrating the retained refrigerant to the liquid storage tank. Similarly, under the high frequency compression refrigeration mode, the refrigerant liquid retained in the liquid storage tank is released as soon as possible to participate in the system circulation operation, and the fluorine pump refrigeration system also has the problem of cavitation caused by low liquid level of the refrigerant in the liquid storage tank under the fluorine pump refrigeration mode.

[0007] The above is the difference caused by the optimal refrigerant circulation amount under different operating conditions, which needs to solve the redundancy adjustment problem of the refrigerant. In addition, there are the following problems: The split type air conditioning equipment usually uses a mechanical driven separated heat pipe, such as a liquid pump or a gas pump driven heat pipe. When the heat pipe and the heat pump share the system, a parallel design of a throttling element and a solenoid valve is usually used. When the heat pump is running, the solenoid valve is closed, and the refrigerant runs through the throttling element to reduce the pressure; when the heat pipe is running, the solenoid valve is opened, and the refrigerant mainly passes through the low-resistance solenoid valve to prevent the large resistance of the throttling element from consuming most of the gravity or the head of the fluorine pump.

[0008] Although the heat pipe and the heat pump share the system to reduce many parts, the debugging and optimization of the system is a very complex problem, and there are some problems that cannot be ignored in the reliable operation of the system. For example, the refrigerant circulation amount in the compression refrigeration mode is much larger than that in the fluorine pump heat pipe circulation, and a large liquid storage tank usually needs to be configured in the system to adjust the difference between the refrigerant circulation amounts of the two; the low-temperature liquid refrigerant and lubricating oil returned by the outdoor condenser in the fluorine pump heat pipe running at low outdoor temperature are prone to oil layering in the liquid storage tank, and the lubricating oil at this time is not easy to return to the compressor just started with the refrigerant liquid, which is likely to cause the compressor to lack oil during the starting stage, and in severe cases, it will damage the compressor.

[0009] Another problem is that the evaporator has not completely evaporated the refrigerant liquid into the gas pipeline, and the causes and technical background are as follows:

[0010] In an air conditioning refrigeration system without using a gas-liquid separator, preventing liquid impact on the compressor is an important problem. The liquid refrigerant in the evaporator enters the compressor with high-speed refrigerant gas, and the liquid impact on the compression surface of the compressor is easy to cause damage.

[0011] In order to prevent the liquid refrigerant in the evaporator from entering the compressor, the gas return main pipe is usually connected above the possible highest liquid level in the evaporator gas collection main pipe, but this is easy to cause the bottom of the gas collection main pipe to store liquid refrigerant and lubricating oil, because the refrigerant flow in the bottom branch is small, the flow rate is low, and it cannot carry enough liquid refrigerant and / or lubricating oil upward, and after a long running time, the bottom of the gas collection main pipe is easy to accumulate liquid refrigerant and retain part of the lubricating oil. When the height of these liquids gradually rises, the bottom branch is easy to form a liquid seal, and the refrigerant flow that can pass through is even less, thereby causing the bottom of the evaporator to form a "liquid storage" phenomenon. Obviously, more lubricating oil will be contained in these liquid refrigerants, which is easy to cause the refrigerant circulation amount of the refrigeration system to be insufficient and the oil return to be insufficient.

[0012] The existing patents 201920758930.1 and 201421133297.4 propose to connect an oil return pipe to the gas return main pipe at the bottom of the evaporator header assembly, and to suck the liquid accumulated at the bottom of the header back to the compressor through the pressure difference. However, both patents have some problems: 1) After shutdown and standing, the high and low pressures of the air conditioning refrigeration system will gradually achieve pressure balance, and the high pressure end will squeeze the liquid refrigerant to accumulate in the evaporator, so the liquid refrigerant at the bottom of the evaporator is easy to return to the compressor suction pipe directly through the oil return pipe, or even to the compressor oil pool, which will cause liquid start-up of the compressor and liquid hammering during the next start-up process; 2) The size of the oil return pipe is specified, but the length design of the oil return pipe is not mentioned, and only the design principle of the pipe diameter of the oil return pipe is proposed. In actual design, the size and length of the oil return pipe need to be determined according to the pressure difference and the amount of return flow. The smaller the diameter of the oil return pipe or the longer the oil return pipe, the smaller the amount of return flow, which may not achieve safe return flow, and eventually still causes the liquid refrigerant and lubricating oil to partially accumulate at the bottom of the evaporator.

[0013] In the fluorine pump refrigeration mode, the liquid seal phenomenon is easy to occur in the gas pipeline between the evaporator and the condenser, which causes the gas flow resistance in these gas pipelines to increase or even affects the gas circulation, thereby increasing the fluorine pump head, reducing the system energy efficiency ratio, and reducing the system performance, and thus it is also necessary to guide the liquid refrigerant at the outlet of the evaporator out to return to the liquid pipeline.

[0014] In summary, it is urgent to solve the problems of refrigerant redundancy adjustment and liquid flow in the evaporator outlet in the fluorine pump compression refrigeration system, which is very necessary for the optimization design of the high-efficiency and stable operation of the fluorine pump compression refrigeration system.

[0015] Since the fluorine pump refrigeration system in the prior art has the technical problems of low liquid level in the liquid tank in the fluorine pump refrigeration mode and causing cavitation, the present application researches and designs a refrigeration system and control method with refrigerant redundancy adjustment function. SUMMARY

[0016] Therefore, the technical problem to be solved by the present application is to overcome the defects of the fluorine pump compression refrigeration system in the prior art, i.e., the low liquid level in the liquid tank in the fluorine pump refrigeration mode and causing cavitation, so as to provide a refrigeration system and control method with refrigerant redundancy adjustment function.

[0017] In order to solve the above problems, the present application provides a refrigeration system with refrigerant redundancy adjustment function, which comprises:

[0018] The fluorine pump, the liquid storage tank, the evaporator and the balance pipe, the liquid storage tank includes an outer cylinder and an inner cylinder, the inner cylinder is located in the inner periphery of the outer cylinder, and the first communication hole is arranged on the cylinder wall of the inner cylinder to communicate the inside of the inner cylinder with the inside of the outer cylinder, the fluorine pump is communicated between the inside of the outer cylinder and the evaporator, one end of the balance pipe is communicated to the inside upper end of the inner cylinder, the other end of the balance pipe is communicated to the outlet end of the evaporator, and in the fluorine pump mode, the balance pipe can introduce fluid from the outlet end of the evaporator to the inside of the inner cylinder to press at least part of the liquid in the inner cylinder into the outer cylinder through the first communication hole to increase the liquid level in the outer cylinder.

[0019] Further comprising a compressor and an oil return assembly, the oil return assembly can recover the oil-containing mixture in the liquid storage tank and deliver the separated oil to the compressor.

[0020] In some embodiments,

[0021] The balance pipe is provided with a one-way valve C, which only allows fluid to flow from the outlet end of the evaporator to the inner cylinder in the balance pipe.

[0022] In some embodiments,

[0023] Further comprising a floating component, the floating component is arranged in the inside of the inner cylinder, and the floating component floats in the liquid in the inner cylinder to rise or fall integrally with the liquid level, a lower limit position plate is arranged below the floating component, and a second communication hole is further arranged on the lower limit position plate, the second communication hole penetrates the upper and lower end faces of the lower limit position plate, the liquid below the lower limit position plate can enter above the lower limit position plate through the second communication hole and float the floating component, and when the liquid level above the lower limit position plate drops to the height of the lower limit position plate, the floating component drops to the second communication hole and blocks the second communication hole.

[0024] In some embodiments,

[0025] The position of the first communication hole is lower than the height of the lower limit position plate; the second communication hole and the floating component are arranged opposite in the vertical direction, and the lower end face area of the floating component is greater than the cross-sectional area of the second communication hole.

[0026] The lower limit position plate is fixedly arranged on the inner wall of the inner cylinder, the outer peripheral wall of the lower limit position plate is sealingly fixed with the inner peripheral wall of the inner cylinder, the lower limit position plate can limit the downward movement of the floating component, and the lower limit position plate is a single-hole plate, that is, the number of the second communication holes is one.

[0027] In some embodiments,

[0028] The lower end of the floating component is further connected with a lower connecting rod, the lower connecting rod is arranged in the second communication hole and can move up and down along the second communication hole, the outer peripheral cross-sectional area of the lower connecting rod is smaller than the cross-sectional area of the second communication hole, and the outer peripheral cross-sectional area of the lower connecting rod is smaller than the area of the lower end surface of the floating component.

[0029] In some embodiments,

[0030] The upper side of the floating component is further provided with an upper limiting plate, the upper limiting plate is fixedly arranged on the inner wall of the inner cylinder, and the upper limiting plate can limit the upward movement of the floating component;

[0031] The upper limiting plate is provided with a third communication hole, the third communication hole penetrates the upper end surface and the lower end surface of the upper limiting plate, so as to communicate the space above the upper limiting plate with the space below the upper limiting plate, so that the liquid and / or gas below the upper limiting plate can enter the space above the upper limiting plate through the third communication hole, and the liquid and / or gas above the upper limiting plate can also enter the space below the upper limiting plate through the third communication hole.

[0032] In some embodiments,

[0033] The upper limiting plate is a porous plate, and the third communication hole is a plurality of third communication holes which are distributed on the upper limiting plate in a spaced manner.

[0034] The upper end of the floating component is further connected with an upper connecting rod, the upper connecting rod is arranged in the third communication hole and can move up and down along the third communication hole, and the outer peripheral cross-sectional area of the upper connecting rod is smaller than the cross-sectional area of the third communication hole.

[0035] In some embodiments,

[0036] The floating component is a float, which comprises an upper structure and a lower structure, the lower end of the upper structure is connected with the upper end of the lower structure, the upper structure is a conical structure, the lower structure is a cylindrical structure, when the upper connecting rod and the lower connecting rod are simultaneously provided, the upper end of the upper structure is connected with the lower end of the upper connecting rod, the outer peripheral cross-sectional area of the upper end of the upper structure is equal to the outer peripheral cross-sectional area of the lower end of the upper connecting rod, and the lower end of the lower structure is connected with the upper end of the lower connecting rod, the outer peripheral cross-sectional area of the lower end of the lower structure is greater than the outer peripheral cross-sectional area of the upper end of the lower connecting rod.

[0037] In some embodiments,

[0038] The evaporator comprises a collecting pipe, the collecting pipe is located at the outlet end of the evaporator, and the other end of the balance pipe is communicated to the inner bottom end of the collecting pipe.

[0039] In some embodiments,

[0040] The condenser, a liquid inlet pipe and a liquid outlet pipe are further included. One end of the liquid inlet pipe is in communication with the condenser and the other end is in communication with the inner top end of the outer cylinder of the liquid storage tank, so as to guide the heat-exchanged refrigerant in the condenser into the liquid storage tank. One end of the liquid outlet pipe is in communication with the inner bottom end of the outer cylinder of the liquid storage tank and the other end is in communication with one end of the fluorine pump.

[0041] In some embodiments,

[0042] The condenser, a liquid inlet pipe and a liquid outlet pipe are further included. One end of the liquid inlet pipe is in communication with the condenser and the other end is in communication with the inner top end of the outer cylinder of the liquid storage tank, so as to guide the heat-exchanged refrigerant in the condenser into the liquid storage tank. One end of the liquid outlet pipe is in communication with the inner bottom end of the outer cylinder of the liquid storage tank and the other end is in communication with one end of the fluorine pump.

[0043] In some embodiments,

[0044] The other end of the balance pipe is in communication with the third pipe or the fifth pipe. Alternatively, the evaporator includes a gas collecting pipe at the outlet end of the evaporator. The other end of the balance pipe is in communication with the inner bottom end of the gas collecting pipe. The inner top end of the gas collecting pipe is in communication with the third pipe.

[0045] In some embodiments,

[0046] The oil return assembly includes a floating body, a hose and an oil return pipe. The floating body is arranged in the outer cylinder and can float in the liquid in the outer cylinder to rise or fall with the liquid level. The floating body is provided with a liquid suction port to suck the oil-containing mixture at the liquid surface. The upper end of the hose is connected to the floating body to rise and fall with the floating body, so as to guide the oil-containing mixture sucked by the floating body. The lower end of the hose is in communication with one end of the oil return pipe. The oil return pipe extends out of the liquid storage tank to guide the oil-containing mixture to the suction end of the compressor.

[0047] In some embodiments,

[0048] The oil return pipeline is provided with a control valve and a heating component, which can heat the mixture of refrigerant and oil in the oil return pipeline to evaporate the refrigerant and separate the lubricating oil.

[0049] In some embodiments,

[0050] The heating component includes fins and / or fins arranged on the part of the pipeline on the oil return pipeline, so that the part of the pipeline forms a finned tube and / or a finned tube, which is arranged at the return air inlet of the evaporator.

[0051] In some embodiments,

[0052] The finned tube and / or finned tube are arranged on the outside and / or inside of the evaporator, and when the finned tube and / or finned tube are arranged on the inside of the evaporator, the finned tube and / or finned tube are integrally formed with the heat exchange tube of the evaporator.

[0053] In some embodiments,

[0054] Further comprising a gas-liquid separator arranged at and communicating with the suction end of the compressor, the other end of the oil return pipeline communicates with the inside of the gas-liquid separator, and the control valve is an electromagnetic valve.

[0055] The application also provides a control method of the refrigeration system with the refrigerant redundancy adjustment function as described above, which comprises:

[0056] A detection step for detecting whether it is during the compressor shutdown or fluorine pump shutdown and detecting the temperature of the liquid storage tank;

[0057] A judgment step for judging the relationship between the temperature of the liquid storage tank and the preset temperature T0;

[0058] A control step for controlling the control valve to open when it is during the compressor shutdown or fluorine pump shutdown and the temperature of the liquid storage tank is less than T0 for more than t0 time, wherein t0 is a preset time.

[0059] In some embodiments,

[0060] The control step controls the control valve to open for t1 time, and then closes the control valve and opens the inner fan opposite to the evaporator to operate for t2 time; and then opens the control valve and the inner fan in turn under the condition that the temperature of the liquid storage tank meets the condition next time, wherein t1 is a first preset time and t2 is a second preset time.

[0061] The refrigeration system and control method with refrigerant redundancy adjustment function have the following beneficial effects:

[0062] 1. The application sets the liquid storage tank as a structure including an outer cylinder and an inner cylinder, and the inner and outer cylinders are connected through a first communication hole, and a balance pipe is combined, one end of the balance pipe is connected to the outlet end of the evaporator, and the other end is connected to the upper end of the inner cylinder, so that in the fluorine pump refrigeration mode, the fluid (including refrigerant gas and / or liquid) with high pressure is introduced from the outlet end of the evaporator into the upper part of the inner cylinder, so that the liquid in the inner cylinder is pressed into the outer cylinder through the first communication hole by the pressure of the high-pressure fluid, so that the refrigerant liquid level of the outer cylinder of the liquid storage tank is higher in the fluorine pump refrigeration mode, that is, the height of the liquid discharge is higher, so that the fluorine pump has enough liquid suction height, effectively reduces the probability of cavitation, solves the problem of cavitation in the fluorine pump refrigeration mode, and in the compression refrigeration mode, the outlet end of the evaporator has low pressure, so that the fluid is not introduced into the upper part of the inner cylinder through the balance pipe, so that in the compression refrigeration mode, the liquid level of the inner cylinder rises, and the liquid level in the outer cylinder drops, and the high-pressure gas in the upper part of the outer cylinder presses the liquid in the outer cylinder into the inner cylinder through the first communication hole, so that the top pressure of the inner cylinder of the liquid storage tank changes in the compression refrigeration mode and the fluorine pump refrigeration mode, and the required optimal refrigerant circulation amount in the two operation modes is automatically adjusted, without increasing the control hardware and control software, and the change of the system pressure is used to automatically balance and adjust the change of the refrigerant liquid storage state in the liquid storage tank, so that the inner cylinder of the liquid storage tank becomes a variable storage space for the refrigerant liquid, the system has high reliability, low cost, no special control adjustment, and the liquid level in the liquid storage tank has automatic balance adjustment function in different operation modes, and solves the problems of cavitation in the fluorine pump refrigeration mode and the refrigerant redundancy caused by the difference in the required refrigerant filling amount in different operation modes of the fluorine pump compression refrigeration system, and solves the control problem of the liquid level in the liquid storage tank; and through the setting of the oil return assembly, the lubricating oil in the liquid storage tank can be pumped back to the compressor in time in the shutdown state (preferably in the case of obvious oil and refrigerant stratification in the shutdown state), so that the situation of lack of oil in the compressor is avoided, and the problem of poor oil return when the compressor starts is solved; further preferably, the heating component is used to heat the oil return pipeline, so that the refrigerant and the lubricating oil are effectively separated, the lubricating oil with high purity is recovered to the compressor, the reliability of the compression refrigeration or fluorine pump refrigeration operation is not affected, and the separation and recovery of the lubricating oil in the liquid storage tank under low temperature conditions are safe and reliable.

[0063] 2. The application can float the floating member when the liquid level in the inner cylinder rises above the lower limit position plate, and drive the floating member to continue to rise as the liquid level rises. This situation applies to the process when the fluorine pump refrigeration mode changes to the compression refrigeration mode. When the liquid level in the inner cylinder decreases, the floating member decreases together with the liquid level. When the liquid level decreases to below the lower limit position plate, the floating member is limited by the lower limit position plate and cannot continue to move downward. At the same time, the floating member blocks the second communication hole, effectively preventing gas above the lower limit position plate from entering below, even into the outer cylinder, preventing the gas refrigerant from being discharged from the liquid storage tank to the fluorine pump or the evaporator, ensuring normal and effective refrigeration. The floating member and the lower limit position plate realize the functions of liquid passage and gas blocking, and can automatically realize the change of the liquid level height between the inner cylinder and the outer cylinder according to different operating modes and different pressures and liquid level heights. The change of the liquid storage state of the refrigerant in the liquid storage tank is automatically balanced and adjusted by using the change of the system pressure and the change of the buoyancy of the float. The refrigerant liquid level in the outer cylinder of the fluorine pump refrigeration mode is higher, so as to ensure that the fluorine pump has sufficient liquid suction height to reduce the probability of cavitation phenomenon. The automatic balance adjustment function is provided in different operating modes, the problems of refrigerant liquid storage and release are solved, and the control problem of the liquid level in the liquid storage tank is effectively solved.

[0064] 3. The other end of the balance pipe is communicated to the inner bottom end of the gas collecting pipe of the evaporator outlet, so as to guide the unevaporated refrigerant liquid at the bottom of the gas collecting pipe out, and directly guide the refrigerant liquid at the bottom of the gas collecting pipe of the evaporator in the fluorine pump refrigeration mode back to the liquid storage tank to participate in system circulation, instead of entering the gas pipeline, so as to solve the problems of storage and release of the unevaporated refrigerant liquid at the outlet of the evaporator, and effectively solve the problems of flow path and flow system design optimization of these refrigerant liquids. BRIEF DESCRIPTION OF DRAWINGS

[0065] Figure 1 is the system principle diagram of the fluorine pump double-circulation refrigeration system with refrigerant redundancy adjustment function of the application (system runs in fluorine pump mode, float descends);

[0066] Figure 2 is the system connection structure diagram of the fluorine pump double-circulation refrigeration system with refrigerant redundancy adjustment function of the application (system runs in compression mode, float floats up);

[0067] Figure 3 is Figure 1 is the structure enlargement diagram of the liquid storage tank part in

[0068] Figure 4 is the structure enlargement diagram of the liquid storage tank part in Figure 2 .

[0069] Reference signs are indicated as:

[0070] 1, compressor; 2, liquid storage tank; 3, condenser; 4, throttle valve; 5, evaporator; 6, outer cylinder; 7, inner cylinder; 8, floating member; 9, first communication hole; 10, fluorine pump; 11, check valve A; 12, check valve C; 13, oil separator; 14, inner fan; 15, check valve B; 16, capillary tube; 17, outer fan; 18, lower limit plate; 19, second communication hole; 20, lower connecting rod; 21, upper limit plate; 22, third communication hole; 23, upper connecting rod; 24, upper structure; 25, lower structure; 26, floating body; 27, hose; 28, control valve; 29, finned tube and / or finned tube; 30, gas-liquid separator;

[0071] 101, liquid inlet pipe; 102, liquid outlet pipe; 103, balance pipe; 104, gas collection pipe; 201, first pipeline; 202, second pipeline; 203, third pipeline; 204, fourth pipeline; 205, fifth pipeline; 206, oil return pipeline. DETAILED DESCRIPTION

[0072] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. The description of the at least one exemplary embodiment is actually only illustrative, but not intended to limit the present application and its application or use in any way. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0073] It should be noted that the terms used herein are only intended to describe specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form unless the context clearly indicates otherwise, and furthermore, it should be understood that when the terms "comprise" and / or "include" are used in the specification, there is a presence of the features, steps, operations, devices, components and / or combinations thereof.

[0074] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and practice described. Accordingly, all such variations are intended to be included within the scope of the present application as defined in the following claims, along with full equivalents thereof.

[0075] In the description of the present application, it is to be understood that the orientation terms such as "front", "back", "up", "down", "left", "right", "transverse", "vertical", "horizontal", "top", "bottom", and the like are generally intended to convey a relative position relationship as shown in the drawings and are for purposes of convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore should not be construed as limiting the scope of the present application; the orientation terms "inner", "outer" refer to the inner and outer relative to the contour of the components themselves.

[0076] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper", and the like can be used herein to describe the spatial positional relationship of one device or feature with respect to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the device as described in the drawings. For example, if the device in the drawings is inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0077] In addition, it should be noted that the use of the terms "first", "second", and the like do not have a special meaning and are used only to distinguish the corresponding components, and therefore should not be construed as limiting the scope of the present application.

[0078] As Figures 1-4As shown, the present application provides a refrigeration system with refrigerant redundancy adjustment function, which comprises:

[0079] A fluorine pump 10, a liquid storage tank 2, an evaporator 5 and a balance pipe 103, the liquid storage tank 2 comprises an outer cylinder 6 and an inner cylinder 7, the inner cylinder 7 is located in the inner periphery of the outer cylinder 6, and a first communication hole 9 is arranged on the cylinder wall of the inner cylinder 7 to enable the inner part of the inner cylinder 7 to communicate with the inner part of the outer cylinder 6, the fluorine pump 10 is communicated between the inner part of the outer cylinder 6 and the evaporator 5, one end of the balance pipe 103 is communicated to the inner upper end of the inner cylinder 7, and the other end of the balance pipe 103 is communicated to the outlet end of the evaporator 5, in the fluorine pump mode, the balance pipe 103 can introduce fluid from the outlet end of the evaporator 5 to the inner part of the inner cylinder 7, so as to press at least part of the liquid in the inner cylinder 7 into the outer cylinder 6 through the first communication hole 9, so as to increase the liquid level height in the outer cylinder 6;

[0080] Further comprising a compressor 1 and an oil return assembly, the oil return assembly can recover the oil-containing mixture (i.e. oil-rich liquid) in the liquid storage tank 2 and can deliver the separated oil to the compressor 1.

[0081] The present application can introduce the fluid (including refrigerant gas and / or refrigerant liquid) with higher pressure from the outlet end of the evaporator into the upper part of the inner cylinder in the fluorine pump refrigeration mode, so that the liquid in the inner cylinder is pressed into the outer cylinder through the first communication hole by the pressure of the high-pressure fluid, so that the refrigerant liquid level of the outer cylinder of the liquid storage tank in the fluorine pump refrigeration mode is higher, that is, the liquid outlet height is higher, so as to ensure that the fluorine pump has sufficient liquid suction height, effectively reduces the probability of cavitation, solves the problem of cavitation in the fluorine pump refrigeration mode, and in the compression refrigeration mode, the fluid is not introduced into the upper part of the inner cylinder through the balance pipe due to the lower pressure of the outlet end of the evaporator, so that the liquid level of the inner cylinder rises and the liquid level in the outer cylinder drops in the compression refrigeration mode. The higher pressure gas in the upper part of the outer cylinder presses the liquid in the outer cylinder into the inner cylinder through the first communication hole, and the top pressure of the inner cylinder of the liquid storage tank changes in the compression refrigeration mode and the fluorine pump refrigeration mode. The required better refrigerant circulation amount in the two operation modes is automatically adjusted without increasing the control hardware and control software. The change of the system pressure realizes the automatic balance adjustment control of the change of the refrigerant liquid storage state in the liquid storage tank, so that the inner cylinder of the liquid storage tank becomes a variable containing space for the refrigerant liquid. The system has high reliability, low cost, no special control adjustment, and automatic balance adjustment function of the liquid level in the liquid storage tank in different operation modes. Simultaneously, the problems of cavitation in the fluorine pump refrigeration mode and the refrigerant redundancy caused by the difference in the required refrigerant filling amount in different operation modes of the fluorine pump compression refrigeration system are solved, and the control problem of the liquid level in the liquid storage tank is solved. Furthermore, through the setting of the oil return assembly, the lubricating oil in the liquid storage tank can be preferably sucked and recovered to the compressor in the shutdown state (preferably in the shutdown state and the case where the oil and refrigerant are obviously layered), so as to avoid the lack of oil in the compressor, and further preferably through the heating of the oil return pipeline by the heating component, the refrigerant and the lubricating oil are effectively separated, the lubricating oil with high purity is recovered to the compressor, and the reliability of the compression refrigeration or fluorine pump refrigeration operation is not affected. The separation and recovery of the lubricating oil in the liquid storage tank under low temperature conditions are safe and reliable.

[0082] As shown in Figure 1 and Figure 3 , the liquid storage tank 2 of the present application preferably comprises a liquid inlet pipe 101, a liquid outlet pipe 102 and a cylinder body; the liquid storage tank cylinder body is composed of an inner cylinder 7 and an outer cylinder 6, the top of the inner cylinder 7 and the outer cylinder 6 is preferably fixedly and sealingly connected, the bottom of the inner cylinder 7 and the outer cylinder 6 is preferably fixedly and sealingly connected, and at least one first communication hole 9 is opened on the side of the bottom end of the inner cylinder 7, and the inner cylinder 7 and the outer cylinder 6 can only communicate through the first communication hole 9.

[0083] The liquid storage tank of the present application further comprises a balance pipe 103, which is located at the top of the liquid storage tank and preferably continuously penetrates the top of the outer cylinder 6 and the inner cylinder 7, so that the inner cylinder 7 is directly communicated with the outside of the liquid storage tank through the balance pipe 103; the balance pipe 103 is preferably fixedly sealed between the outer cylinder 6 and the inner cylinder 7 by welding.

[0084] In some embodiments,

[0085] The balance pipe 103 is provided with a one-way valve C12, which only allows fluid to flow from the outlet end of the evaporator 5 to the inner cylinder 7 in the balance pipe 103.

[0086] The present application can effectively prevent the gas in the inner cylinder from flowing out to the outlet end of the evaporator through the balance pipe, prevent the refrigerant liquid or gas from being pressed out through the balance pipe due to the higher pressure of the outer cylinder than the outlet end of the evaporator in the compression refrigeration mode, avoid the situation that the evaporator is short-circuited without the refrigerant passing through the evaporator, avoid the decline of refrigeration performance, and ensure the reliable and stable operation of the refrigeration mode.

[0087] As Figure 1 shown, the fluorine pump compression refrigeration system comprising the novel liquid storage tank further comprises a balance pipe, which is connected between the outlet of the evaporator and the balance pipe inlet of the liquid storage tank, and is provided with a one-way valve C, the flow direction of which only allows the refrigerant to flow from the outlet of the evaporator to the inner cylinder space of the liquid storage tank through the balance pipe of the liquid storage tank;

[0088] In some embodiments,

[0089] Further comprising a floating component 8, which is arranged in the inner cylinder 7 and floats in the liquid in the inner cylinder 7 to rise or fall integrally with the liquid level, and is provided with a lower limit plate 18 below, and a second communication hole 19 is further arranged on the lower limit plate 18, which penetrates the upper and lower end faces of the lower limit plate 18, and the liquid below the lower limit plate 18 can enter the upper side of the lower limit plate 18 through the second communication hole 19 and float the floating component 8, and when the liquid height above the lower limit plate 18 decreases to the height of the lower limit plate 18, the floating component 8 is lowered to the second communication hole 19 and blocks the second communication hole 19.

[0090] The application can float the floating part when the liquid level in the inner cylinder rises to above the lower limiting plate, and drive the floating part to continuously rise with the rising of the liquid level, which is applicable to the process when the fluorine pump refrigeration mode is converted into the compression refrigeration mode, and when the liquid level in the inner cylinder falls, the floating part falls together with the liquid level, and when the liquid level falls to below the lower limiting plate, the floating part is limited by the lower limiting plate and cannot continue to move downward, and the floating part blocks the second communication hole, which can effectively prevent the gas above the lower limiting plate from entering below, even into the outer cylinder, prevent the gas refrigerant from being discharged from the liquid storage tank to the fluorine pump or the evaporator, and ensure normal and effective refrigeration, the floating part and the lower limiting plate realize the functions of liquid communication and gas blocking, can automatically realize the change of the liquid level height between the inner cylinder and the outer cylinder according to different operation modes and different pressures and liquid level heights, utilize the change of the system pressure and the change of the buoyancy of the floating plug to realize the automatic balance adjustment and control of the change of the refrigerant liquid storage state in the liquid storage tank, the refrigerant liquid level height of the outer cylinder of the liquid storage tank is higher in the fluorine pump refrigeration mode, so that the fluorine pump has sufficient liquid suction height to reduce the probability of cavitation phenomenon, has the automatic balance adjustment function in different operation modes, solves the problems of refrigerant liquid storage and release, and effectively solves the control problem of the liquid level in the liquid storage tank.

[0091] In some embodiments,

[0092] The first communication hole 9 is located below the height of the lower limiting plate 18, and the second communication hole 19 is vertically opposite to the floating part 8, and the lower end surface area of the floating part 8 is greater than the cross-sectional area of the second communication hole 19.

[0093] The first communication hole is arranged below the height of the lower limiting plate, so that the refrigerant liquid in the outer cylinder can enter below the lower limiting plate of the inner cylinder through the first communication hole, and then the liquid pushes the floating plug to float upward through the second communication hole of the lower limiting plate as the liquid level in the inner cylinder rises, so that the functions and effects of upward liquid communication are realized, and the second communication hole is vertically opposite to the floating part, and the lower end area of the floating part is greater than the area of the second communication hole, so that the floating part can completely block the second communication hole when moving downward, so that the gas above the lower limiting plate cannot enter below the lower limiting plate when the liquid level in the inner cylinder falls below the lower limiting plate, and then the gas cannot enter the outer cylinder, and the situation that the gas enters the evaporator to cause the refrigeration performance to decrease does not occur.

[0094] In some embodiments,

[0095] The lower limit plate 18 is fixedly arranged on the inner wall of the inner cylinder 7, the outer peripheral wall of the lower limit plate 18 is sealingly fixed with the inner peripheral wall of the inner cylinder 7, the lower limit plate 18 can limit the downward movement of the floating component 8, and the lower limit plate 18 is a single-hole plate, that is, the number of the second communication holes 19 is one.

[0096] The lower limit plate of the present application is preferably fixed to the inner wall of the inner cylinder, thereby limiting the downward movement of the floating component through the fixed lower limit plate when the floating component moves up and down, and the lower limit plate of the present application is further preferably a single-hole plate, that is, the number of the second communication holes is one, which can ensure that the fluid can push the floating component to move upward and make the fluid enter above the lower limit plate through the single second communication hole when the liquid level rises, and can also ensure that the floating component can completely block the upper and lower spaces of the lower limit plate through the single second communication hole when the liquid level drops, effectively realizing the function of liquid passage and gas blocking, avoiding the gas entering below the lower limit plate and then entering the outer cylinder, and further preventing the gas from entering the evaporator to cause the refrigeration performance to decrease; the outer peripheral wall of the lower limit plate 18 is sealingly fixed with the inner peripheral wall of the inner cylinder 7 (such as by welding technology, thereby ensuring that the second communication hole 19 is the only passage of the lower limit plate 18), which can make the liquid below the lower limit plate enter above only through the second communication hole, and the liquid above can enter below only through the second communication hole, thereby improving the gas blocking effect of the floating component and improving the function of liquid passage and gas blocking.

[0097] In some embodiments,

[0098] The lower end of the floating component 8 is further connected with a lower connecting rod 20, the lower connecting rod 20 is arranged in the second communication hole 19 and can move up and down along the second communication hole 19, the outer peripheral cross-sectional area of the lower connecting rod 20 is smaller than the cross-sectional area of the second communication hole 19, and the outer peripheral cross-sectional area of the lower connecting rod 20 is smaller than the area of the lower end surface of the floating component 8.

[0099] The lower connecting rod is preferably connected to the lower end of the floating component, which can be inserted into the second communication hole to guide and limit the upward and downward movement of the floating component, prevent the floating component from moving horizontally or obliquely, and ensure that the floating component can always move vertically to block the second communication hole and realize the function of liquid passage and gas blocking, and the outer peripheral cross-sectional area of the lower connecting rod is preferably smaller than the cross-sectional area of the second communication hole, thereby ensuring that the lower connecting rod can move smoothly in the second communication hole without resistance.

[0100] In some embodiments,

[0101] An upper limiting plate 21 is further arranged above the floating component 8, and the upper limiting plate 21 is fixedly arranged on the inner wall of the inner cylinder 7, and the upper limiting plate 21 can limit the upward movement of the floating component 8.

[0102] The upper limiting plate is further arranged above the floating component, and the upper limiting plate is fixedly arranged on the inner wall of the inner cylinder, so that the upward movement of the floating component can be effectively limited, the lower connecting rod is prevented from being pulled out of the second communication hole due to the excessive upward movement of the floating component, and the floating component can normally and reliably move along the vertical direction.

[0103] In some embodiments,

[0104] The upper limiting plate 21 is provided with a third communication hole 22 penetrating the upper end face and the lower end face of the upper limiting plate 21, so as to communicate the space above the upper limiting plate 21 with the space below the upper limiting plate 21, so that the refrigerant liquid and / or gas below the upper limiting plate 21 can enter the space above the upper limiting plate 21 through the third communication hole 22, and the refrigerant liquid and / or gas above the upper limiting plate 21 can enter the space below the upper limiting plate 21 through the third communication hole 22.

[0105] The third communication hole arranged on the upper limiting plate can make the refrigerant liquid and / or gas below the upper limiting plate enter the space above the upper limiting plate through the third communication hole, and the refrigerant liquid and / or gas above the upper limiting plate can also enter the space below the upper limiting plate through the third communication hole, so that the refrigerant liquid can enter the space above the upper limiting plate when the liquid level rises, and the refrigerant liquid can enter the space below the upper limiting plate when the liquid level falls.

[0106] In some embodiments,

[0107] The upper limiting plate 21 is a porous plate, and the third communication hole 22 is a plurality of third communication holes 22 which are distributed on the upper limiting plate 21.

[0108] The upper limiting plate of the present application is preferably a porous plate, that is, the insertion of the upper connecting rod into one of the third communication holes will not affect the flow of the refrigerant fluid through the other third communication holes, so as to ensure the normal and effective flow of the refrigerant liquid from the space above the upper limiting plate to the space below the upper limiting plate or from the space below the upper limiting plate to the space above the upper limiting plate.

[0109] The inner cylinder of the liquid storage tank of the present application is preferably horizontally fixed with a low single-hole plate (lower limit plate 18) and a high multi-hole plate (upper limit plate 21), the single-hole plate and the multi-hole plate are preferably sealed and fixed with the wall of the inner cylinder by welding, a flow-through hole (second communication hole 19) located on the same vertical line is arranged in the middle of the single-hole plate and the multi-hole plate, and the multi-hole plate further has at least one other flow-through hole (third communication hole 22), which is preferably as close as possible to the edge of the multi-hole plate, i.e. as close as possible to the wall of the inner cylinder (to prevent being blocked by the floating plug after being floated up), so that the multi-hole plate has at least two third communication holes 22.

[0110] The bottom end surface of the low single-hole plate of the present application is higher than the first communication hole 9 on the side wall of the bottom of the inner cylinder; the high multi-hole plate is higher than the low single-hole plate and preferably ensures that the two are in a horizontal parallel spaced state;

[0111] In some embodiments,

[0112] The upper end of the floating component 8 is further connected with an upper connecting rod 23, which is inserted into the third communication hole 22 and can move up and down along the third communication hole 22, and the outer peripheral cross-sectional area of the upper connecting rod 23 is smaller than the cross-sectional area of the third communication hole 22.

[0113] The present application further has the structure of the upper connecting rod inserted into the third communication hole, which can guide and limit the upper end of the floating component, so that the upper end of the floating component can continuously and effectively move in the vertical direction, avoiding movement in the horizontal direction or tilting movement, and the cross-sectional area of the upper connecting rod being smaller than the cross-sectional area of the third communication hole can ensure that the upper connecting rod can normally and smoothly move in the third communication hole.

[0114] In some embodiments,

[0115] The floating component 8 is a floating plug, which includes an upper structure 24 and a lower structure 25, the lower end of the upper structure 24 is connected with the upper end of the lower structure 25, the upper structure 24 is a conical structure, and the lower structure 25 is a cylindrical structure, when the upper connecting rod 23 and the lower connecting rod 20 are both present, the upper end of the upper structure 24 is connected with the lower end of the upper connecting rod 23, the outer peripheral cross-sectional area of the upper end of the upper structure 24 is equal to the outer peripheral cross-sectional area of the lower end of the upper connecting rod 23, and the lower end of the lower structure 25 is connected with the upper end of the lower connecting rod 20, the outer peripheral cross-sectional area of the lower end of the lower structure 25 is larger than the outer peripheral cross-sectional area of the upper end of the lower connecting rod 20.

[0116] This is the preferred structure of the floating component of the present application, which is a float structure composed of an upper structure and a lower structure, the upper structure is preferably a cone, the upper end of which is connected to the lower end of the upper connecting rod, and the outer cross-sectional area of the two is preferably equal, the upper end of the upper structure can guide the refrigerant fluid (including liquid and / or gas) flowing from top to bottom towards the lower part, so as not to deposit on the upper end surface of the floating component, and the lower structure is preferably a column, the lower end of which is connected to the lower connecting rod, and the cross-sectional area of the lower structure is larger than the upper end cross-sectional area of the lower connecting rod, which can ensure that when the floating component moves downward to the lower limit plate, it can effectively block the second communication hole on the lower limit plate through the large-area lower end surface, realizing the function of liquid communication and gas blocking.

[0117] The present application further preferably projects in the vertical plane, the upper structure is triangular, and the lower structure is rectangular structure, the upper structure is preferably a circular cone, and the lower structure is preferably a circular column.

[0118] The upper and lower ends of the float inside the liquid storage tank are also connected with thin rod-shaped components (upper connecting rod 23 and lower connecting rod 20), and the middle float is a large cross-section column structure; the thin rod components at the upper and lower ends of the float are respectively inserted into the flow-through holes in the middle of the multi-hole plate and the single-hole plate, so that the float is clamped between the multi-hole plate and the single-hole plate and can freely float up or down while being unable to be detached from the single-hole plate and / or the multi-hole plate.

[0119] The lower end surface of the float is preferably a horizontal surface, and when the float floats against the lower end surface of the multi-hole plate, the upper end surface of the float cannot completely block the third communication hole at the edge of the multi-hole plate, that is, the multi-hole plate of the present application can ensure that the communication state at its upper and lower ends is achieved under any circumstances and cannot be closed and blocked.

[0120] The upper end surface of the float of the present application includes but is not limited to a horizontal surface, a conical surface, etc.; the horizontal cross section of the float includes but is not limited to a circular shape, a rectangular shape, a rhombus, etc.

[0121] The horizontal cross-sectional area of the thin rod component at the lower end of the float is preferably smaller than the horizontal area of the flow-through hole in the middle of the single-hole plate, and the horizontal cross-sectional area of the thin rod component at the upper end of the float is smaller than the horizontal area of the flow-through hole in the middle of the multi-hole plate, so as to ensure that when the float rises and its large cross-section column structure lower end horizontal surface is away from the upper end surface of the single-hole plate, the refrigerant liquid can flow up and down through the flow-through hole of the single-hole plate, and therefore when the float rises and separates from the single-hole plate, the uppermost space of the inner cylinder can sequentially communicate with the space of the outer cylinder through the flow-through hole of the multi-hole plate, the flow-through hole of the single-hole plate, and the communication hole on the sidewall of the bottom of the inner cylinder (as shown in Figure 4 The isolation state of the uppermost space of the inner cylinder and the space of the outer cylinder is as shown in Figure 3 At this time, the float is lowered and abuts against the upper end surface of the single-hole plate.

[0122] In some embodiments,

[0123] The floating component 8 has a central axis, the axes of the upper connecting rod 23 and the lower connecting rod 20 are coincident with the central axis, and the axes of the upper structure 24 and the lower structure 25 are also coincident with the central axis.

[0124] The application can ensure the integrated up-and-down movement in the vertical direction by setting the axes of the upper connecting rod, the lower connecting rod, the upper structure and the lower structure of the floating component in the direction of the central axis, i.e., the axes of the four are coincident, and even if rotating, no horizontal movement or tilting occurs, the reliable and stable floating of the float is ensured, and the effect of liquid passage and gas blocking is achieved.

[0125] In some embodiments,

[0126] The evaporator 5 comprises a gas collecting pipe 104 located at the outlet end of the evaporator 5, and the other end of the balance pipe 103 is communicated to the inner bottom end of the gas collecting pipe 104.

[0127] The application can also guide the un-evaporated refrigerant liquid at the bottom of the gas collecting pipe out, and directly guide the refrigerant liquid at the bottom of the gas collecting pipe of the evaporator in the fluorine pump refrigeration mode back to the liquid storage tank for participating in system circulation as soon as possible, instead of entering the gas pipeline, solve the problems of storage and release of the un-evaporated refrigerant liquid at the outlet of the evaporator, and effectively solve the problems of flow path and circulation system design optimization of the refrigerant liquid.

[0128] The application adds a new type of liquid storage tank in the fluorine pump compression refrigeration system, the liquid storage tank is designed as a double-cylinder structure, the first communication hole is arranged near the bottom connection between the inner cylinder space and the outer cylinder space, the inner cylinder is provided with a horizontal low-position single-hole plate (lower limiting plate) and a horizontal high-position multi-hole plate (upper limiting plate) and both are higher than the first communication hole, a float is arranged between the two hole plates and is limited between the two hole plates; the top of the inner cylinder is connected to the bottom of the gas collecting pipe of the evaporator, and a one-way valve is arranged on the connecting pipeline to limit the fluid to flow only from the evaporator to the inner cylinder of the liquid storage tank.

[0129] The beneficial effects of the present application are as follows: by using the top pressure change of the inner cylinder of the liquid storage tank in the compression refrigeration mode and the fluorine pump refrigeration mode, the optimal refrigerant circulation amount required in the two operation modes is effectively adjusted, without increasing the control hardware and control software, the change of the system pressure and the change of the buoyancy of the float are used to automatically balance and adjust the change of the refrigerant liquid storage state in the liquid storage tank, so that the inner cylinder of the liquid storage tank becomes a variable accommodation space for the refrigerant liquid, and the refrigerant liquid level height of the outer cylinder of the liquid storage tank in the fluorine pump refrigeration mode is higher, so as to ensure that the fluorine pump has sufficient liquid suction height to reduce the probability of cavitation phenomenon, the system has high reliability, low cost, no special control adjustment, and the liquid level in the liquid storage tank has automatic balance adjustment function in different operation modes.

[0130] The present application solves the following technical problems:

[0131] 1) The problem of cavitation in the fluorine pump mode;

[0132] 2) The problem of refrigerant redundancy caused by the difference in the required refrigerant filling amount in different operation modes of the fluorine pump compression refrigeration system, and the control problem of the liquid level in the liquid storage tank;

[0133] 3) The problem of storage and release of the refrigerant liquid that has not been evaporated at the outlet of the evaporator, and the problem of optimizing the system design of the flow path and flow of the refrigerant liquid.

[0134] In order to solve the problem 2 in the background art, as shown in Figure 2 , the preferred embodiment of the present application is that the inlet of the one-way valve C is connected to the bottom of the gas collecting pipe of the evaporator (i.e. the balance pipe is connected to the bottom of the gas collecting pipe of the evaporator), so that the refrigerant liquid accumulated at the bottom of the gas collecting pipe can be smoothly discharged and returned to the liquid storage tank to participate in the fluorine pump refrigeration cycle again (i.e. Figure 2 is Figure 1 one of the preferred embodiments), or part of the refrigerant fluid is led out from the bottom of the gas collecting pipe to the upper space of the inner cylinder of the liquid storage tank, so as to force the refrigerant liquid in the space of the inner cylinder of the liquid storage tank to transfer to the space of the outer cylinder, and ensure that the float is lowered to abut on the single-hole plate to prevent the refrigerant gas from entering the space of the outer cylinder (as shown in Figure 1 or Figure 3 ).

[0135] In some embodiments,

[0136] The compressor 1, the condenser 3, a liquid inlet pipe 101 and a liquid outlet pipe 102 are further included, one end of the liquid inlet pipe 101 is communicated with the condenser 3 and the other end is communicated with the inner top end of the outer cylinder 6 of the liquid storage tank 2, so that the refrigerant in the condenser 3 after heat exchange can be introduced into the liquid storage tank 2, one end of the liquid outlet pipe 102 is communicated with the inner bottom end of the outer cylinder 6 of the liquid storage tank 2 and the other end is communicated with one end of the fluorine pump 10.

[0137] This is a further preferred structure of the present application, the liquid inlet pipe is communicated with the top end of the outer cylinder, which can introduce the refrigerant in the condenser after heat exchange into the outer cylinder of the liquid storage tank, the liquid outlet pipe is communicated with the inner bottom end of the outer cylinder, which can lead the refrigerant (preferably refrigerant liquid) in the outer cylinder to the fluorine pump, the inner cylinder is used to lead the refrigerant liquid below the outer cylinder to the inner cylinder, especially to increase the pressure at the top end of the inner cylinder in the fluorine pump refrigeration mode, so as to increase the liquid amount and the liquid height of the outer cylinder, and ensure that the liquid height is sufficient in the fluorine pump mode to avoid the phenomenon of cavitation, and in the compression mode, the liquid level height of the inner and outer cylinders is almost equal, which can automatically adjust the height of the liquid level of the outer cylinder according to different modes, the greater the frequency of the compressor in the compression mode, the higher the pressure at the liquid inlet pipe, and the lower the liquid level in the inner and outer cylinders, so that the liquid storage amount can be automatically adjusted according to different modes and the frequency of the compressor, the problem of refrigerant redundancy caused by the difference in the required refrigerant filling amount is solved, and the problem of control of the liquid level in the liquid storage tank is solved.

[0138] The liquid outlet pipe 102 of the present application is preferably arranged at the bottom of the liquid storage tank, and the liquid inlet pipe 101 is preferably arranged at the top of the outer cylinder space of the liquid storage tank 2 and / or the bottom of the liquid storage tank.

[0139] In some embodiments,

[0140] The first pipeline 201, the second pipeline 202, the third pipeline 203, the fourth pipeline 204, the fifth pipeline 205, the throttle valve 4, the one-way valve A11, the one-way valve B15 and the oil separator 13 are further included, one end of the fluorine pump 10 is communicated to one end of the evaporator 5 through the first pipeline 201, the throttle valve 4 is arranged on the first pipeline 201, one end of the second pipeline 202 is communicated to the liquid outlet pipe 102 and the other end is communicated to the first pipeline 201 at a position between the fluorine pump 10 and the throttle valve 4, the one-way valve A11 allowing fluid to flow only from the liquid outlet pipe 102 to the first pipeline 201 is arranged on the second pipeline 202; the other end of the evaporator 5 is communicated to the third pipeline 203, the third pipeline 203 is communicated to the suction end of the compressor 1 through the fourth pipeline 204, the third pipeline 203 is further communicated to the exhaust end of the compressor 1 through the fifth pipeline 205, the one-way valve B15 allowing refrigerant fluid to flow only from the suction end to the exhaust end of the compressor 1 is arranged on the fifth pipeline 205, and the oil separator 13 is further arranged between the exhaust end of the compressor 1 and the condenser 3.

[0141] This is a further preferred structure of the refrigeration system of the present application, that is, the one-way valve A is the pipeline through which the refrigerant flows in the compression refrigeration mode, and the one-way valve B is the pipeline through which the refrigerant flows in the fluorine pump mode, the one-way valve A effectively ensures that the refrigerant at the outlet end of the fluorine pump cannot directly return to the inlet end of the fluorine pump, and the one-way valve B effectively ensures that the refrigerant at the outlet end of the compressor cannot directly return to the inlet end of the compressor.

[0142] The present application adds a new type of liquid storage tank in the fluorine pump compression refrigeration system, the liquid storage tank is designed as a double-cylinder structure, the first communication hole is arranged near the bottom connection between the inner cylinder space and the outer cylinder space, the horizontal low-position single-hole plate (lower limiting plate) and the horizontal high-position multi-hole plate (upper limiting plate) are arranged in the inner cylinder and are higher than the first communication hole (to ensure the normal floating of the float and the function of liquid passage and gas blocking), the float is arranged between the two hole plates and is limited between the two hole plates; the top of the inner cylinder is connected to the bottom of the gas collecting pipe of the evaporator, and the one-way valve is arranged on the connecting pipeline to limit the fluid to flow only from the evaporator to the inner cylinder of the liquid storage tank.

[0143] By the one-way valve between the evaporator and the liquid storage tank, in the compression refrigeration mode, the one-way valve is in the reverse high-pressure cut-off state, the float in the liquid storage tank rises under the action of liquid buoyancy, the inner cylinder liquid level of the liquid storage tank rises, so that more refrigerant liquid can be stored to meet the less refrigerant circulating amount required in the compression refrigeration mode; in the fluorine pump refrigeration mode, the one-way valve is in the forward high-pressure flow state, the refrigerant fluid at the bottom of the gas collecting pipe fills into the inner cylinder of the liquid storage tank to force the refrigerant liquid to flow to the outer cylinder from the flow-through hole of the single-hole plate, so that the float descends and blocks the flow-through hole of the single-hole plate, so as to meet the more refrigerant circulating amount required in the fluorine pump refrigeration mode.

[0144] As can be known from the above, the liquid level self-balancing adjustment function of the liquid storage tank can be realized to meet the better refrigerant circulating amount in different modes, and the refrigerant liquid at the bottom of the evaporator gas collecting pipe in the fluorine pump refrigeration mode can be directly guided back to the liquid storage tank to participate in system circulation without entering the gas pipeline.

[0145] As shown in Figure 1 and Figure 2 , the fluorine pump compression refrigeration system is sequentially connected by a compressor 1, a condenser 3, a liquid storage tank 2, a fluorine pump 10, a throttling valve 4 and an evaporator 5;

[0146] The fluorine pump compression refrigeration system further comprises a one-way valve A11, the liquid outlet pipe 102 of the liquid storage tank 2 is connected to the inlet of the fluorine pump 10 and the inlet of the one-way valve A11, the outlet of the one-way valve A11 is connected between the outlet of the fluorine pump 10 and the inlet of the throttling valve 4, and the flow direction of the one-way valve A11 is only allowed to be directed from the liquid outlet pipe 102 of the liquid storage tank 2 to the inlet of the throttling valve 4.

[0147] The fluorine pump compression refrigeration system further comprises a one-way valve B15, the one-way valve B15 is connected in parallel to bypass the compressor, the inlet and the outlet of the one-way valve B15 are connected to the suction port and the exhaust port of the compressor 1 respectively, and the flow direction of the one-way valve B15 is only allowed to be directed from the inlet of the compressor 1 to the outlet of the compressor 1.

[0148] The fluorine pump compression refrigeration system further comprises an oil separator 13 and a capillary tube 16 for oil return, the oil separator 13 is connected between the exhaust port of the compressor 1 and the inlet of the condenser 3, the air inlet of the oil separator 13 is connected to the exhaust port of the compressor 1, the air outlet of the oil separator 13 is connected to the inlet of the condenser 3, and the capillary tube 16 is connected between the oil outlet of the oil separator 13 and the suction port of the compressor 1.

[0149] In some embodiments,

[0150] The other end of the balance pipe 103 is communicated to the third pipeline 203 or the fifth pipeline 205; or the evaporator 5 comprises a gas collecting pipe 104 located at the outlet end of the evaporator 5, and the other end of the balance pipe 103 is communicated to the inner bottom end of the gas collecting pipe 104, and the inner top end of the gas collecting pipe 104 is communicated with the third pipeline 203.

[0151] This is the preferred connection position and connection mode of the balance pipe of the present application. The other end of the balance pipe is preferably communicated to the third pipeline or the fifth pipeline, which can effectively introduce the fluid at the outlet end of the evaporator to the top of the inner cylinder, or the other end of the balance pipe is communicated to the inner bottom end of the gas collecting pipe, which can guide the refrigerant liquid not evaporated at the bottom of the gas collecting pipe out as soon as possible, and directly guide the refrigerant liquid at the bottom of the gas collecting pipe of the evaporator in the fluorine pump refrigeration mode back to the liquid storage tank to participate in the system circulation, instead of entering the gas pipeline, thereby solving the problems of storage and release of the refrigerant liquid not evaporated at the outlet end of the evaporator, effectively solving the problems of flow path and system design optimization of the refrigerant liquid, and the inner top end of the gas collecting pipe is communicated with the third pipeline, which can guide the refrigerant gas after evaporation out of the third pipeline to the suction port of the compressor or into the condenser, thereby ensuring that the suction of the compressor does not carry liquid.

[0152] For the convenience of understanding and description, Figure 1 The state of the liquid storage tank in the fluorine pump refrigeration mode is shown (also refer to Figure 3 ), Figure 2 The state of the liquid storage tank in the compression refrigeration mode is shown (also refer to Figure 4 ), and the working principle of the fluorine pump compression refrigeration system, the circulating flow path of the refrigeration system, and the working state of the components are described as follows:

[0153] A) As shown in Figure 1 , the main flow path of the refrigerant in the fluorine pump refrigeration mode: fluorine pump → throttling valve → evaporator → one-way valve B → oil separator → condenser → liquid storage tank → fluorine pump.

[0154] Description:

[0155] a1) Part of the refrigerant at the outlet end of the evaporator also enters the oil separator through the gas-liquid separator and the capillary tube and then enters the condenser, that is, this flow path is in parallel with the flow path of the one-way valve B, but the refrigerant flow at the one-way valve B is larger, and the refrigerant flow in the flow path of the capillary tube can be ignored;

[0156] a2) When the fluorine pump works, the outlet pressure is higher than the inlet pressure, that is, at this time, the one-way valve A is in a reverse high-pressure cut-off state and does not flow, that is, the one-way valve A can prevent the refrigerant liquid at the outlet of the fluorine pump from directly returning to the inlet of the fluorine pump;

[0157] a3) The fluorine pump outlet pressure is the highest system pressure, and the fluorine pump inlet pressure is the lowest system pressure, and the pressure gradually decreases in the direction of the flow of the refrigerant. Because the pressure at the outlet of the evaporator is higher than the pressure at the top of the liquid accumulator, the check valve C is in a positive high-pressure flow state at this time, so part of the refrigerant at the bottom outlet of the evaporator gas collector will flow into the inner cylinder of the liquid accumulator from the check valve C. If there is enough liquid flowing from the check valve C into the inner cylinder space of the liquid accumulator, the float will rise, and at this time, the refrigerant liquid at the top of the inner cylinder will flow into the outer cylinder space from the flow hole of the single-hole plate. When the refrigerant liquid at the top of the inner cylinder is insufficient or even all refrigerant gas, the buoyancy of the float is insufficient to make the float drop until the flow hole of the single-hole plate is blocked, so the refrigerant gas at the top of the inner cylinder cannot enter the outer cylinder. Therefore, the float in the liquid accumulator has an automatic balancing and adjusting effect in the fluorine pump refrigeration mode. Because the inner cylinder space is mostly refrigerant gas, the amount of refrigerant liquid stored in the liquid accumulator will be less, that is, the circulating amount of refrigerant participating in the system operation will be more, thereby meeting the optimal refrigerant circulating amount requirement of the fluorine pump refrigeration mode; because the liquid accumulator at this time basically only relies on the outer cylinder to participate in the refrigerant circulation, the height of the refrigerant liquid level in the outer cylinder will be larger, which meets the larger suction height required for safe operation of the fluorine pump, thereby reducing the probability of occurrence of the fluorine pump cavitation phenomenon, and the fluorine pump operates more safely and reliably.

[0158] B) As shown in Figure 2 , the main refrigerant flow path of the compression refrigeration mode: compressor → oil separator → condenser → liquid accumulator → check valve A → throttling valve → evaporator → gas-liquid separator → compressor.

[0159] Explanation:

[0160] b1) The lubricating oil separated in the oil separator returns to the compressor suction port through the capillary tube under the action of the pressure difference between high pressure and low pressure. Sometimes there will be a small amount of high-pressure refrigerant gas returning to the compressor suction port from the capillary tube, but it can basically be ignored;

[0161] b2) Part of the refrigerant liquid from the liquid outlet pipe of the liquid accumulator will also flow through the impeller gap of the fluorine pump, that is, the check valve A and the fluorine pump are in parallel flow at this time, but the refrigerant liquid flow at the check valve A is larger, and the refrigerant liquid flow from the fluorine pump can be ignored;

[0162] b3) the compressor discharge pressure is the highest pressure in the system, the compressor suction pressure is the lowest pressure in the system, the pressure gradually decreases along the flow direction of the refrigerant, and the inlet of the throttling valve is high pressure and the outlet is low pressure. Because the outlet of the check valve C is connected to the high-pressure liquid tank, and the inlet of the check valve C is connected to the low-pressure evaporator header, the check valve C is in a reverse high-pressure cut-off non-flow state at this time, so the refrigerant liquid in the outer cylinder of the liquid tank can enter the inner cylinder to float the float, and the refrigerant liquid in the outer cylinder enters the upper space of the inner cylinder in turn through the communication hole on the side wall of the inner cylinder bottom, the flow hole of the single-hole plate and the flow hole of the multi-hole plate. Therefore, the refrigerant liquid level height of the inner cylinder and the outer cylinder remains the same (U-shaped tube communication device principle), so that the liquid tank can store more refrigerant liquid in the compression refrigeration mode, that is, the refrigerant circulating amount participating in the system operation will be less, thereby meeting the optimal refrigerant circulating amount demand of the compression refrigeration mode.

[0163] In some embodiments,

[0164] The oil return assembly includes a floating body 26, a hose 27 (i.e. a flexible tube that can be bent) and an oil return pipeline 206. The floating body 26 is arranged inside the outer cylinder 6 and can float in the liquid in the outer cylinder 6 to rise or fall integrally with the liquid level height. A liquid suction port is arranged on the floating body 26 to suck in the oil-containing mixture (i.e. oil-rich liquid) at the liquid surface. The upper end of the hose 27 is connected to the floating body 26 to rise and fall integrally with the floating body 26 to guide out the oil-containing mixture sucked in by the floating body 26. The lower end of the hose 27 is in communication with one end of the oil return pipeline 206, which extends out of the liquid tank 2 to guide the oil-containing mixture to the suction end of the compressor 1.

[0165] This is the preferred structure of the oil return assembly of the present application. The floating body can float in the liquid (partly above the liquid surface and partly below the liquid surface), and the density thereof is preferably less than that of the lubricating oil. Therefore, the lubricating oil can be sucked in from the liquid surface through the liquid suction port. The upper end of the hose is connected to the floating body to rise and fall integrally with the floating body, so as to guide the lubricating oil sucked in by the floating body downward to the oil return pipeline and further to the compressor, effectively achieving the recovery of the lubricating oil in the liquid tank and the delivery of the lubricating oil to the compressor, thereby ensuring the normal and reliable operation of the compressor.

[0166] The floating body of the application is preferably a floating ball, that is, the liquid storage tank 2 of the application further comprises a floating ball and a hose 27, the floating ball is connected to an oil return pipeline 206 through the hose 27, the oil return pipeline 206 is arranged at the bottom of the liquid storage tank, and the oil-rich liquid in the upper layer of the liquid storage tank flows out of the liquid storage tank 2 through the floating ball, the hose 27 and the oil return pipeline 206; the floating ball and the hose 27 are preferably made of low-density materials, and a liquid inlet is arranged on the floating ball and communicated to the hose 27, and the density of the floating ball and the hose 27 is lower than the density of the lubricating oil at the highest design operating temperature of the unit (the density of the lubricating oil is generally negatively correlated with the temperature).

[0167] In some embodiments,

[0168] The oil return pipeline 206 is provided with a control valve 28, and a heating component is arranged on the oil return pipeline 206, which can heat the mixture of refrigerant and oil in the oil return pipeline 206 to evaporate the refrigerant and separate the lubricating oil.

[0169] The application can effectively control the oil return through the control valve arranged on the oil return pipeline, especially the control valve can be opened to realize the oil return only when the conditions are met (the conditions are preferably that the unit is in a shutdown state and the temperature of the liquid storage tank is low for a certain period of time, at which time the stratification of the lubricating oil and the refrigerant is obvious, and the lubricating oil can be pumped to obtain oil with high purity), and further through the arrangement of the heating component, the mixture of the lubricating oil and the refrigerant can be heated, because the boiling point of the refrigerant is generally lower than that of the lubricating oil, so the refrigerant is evaporated into a gaseous state, the lubricating oil is separated from the refrigerant, the lubricating oil is purified, and the lubricating oil is transported to the compressor, so that enough lubricating oil is ensured for the next start of the compressor, the compressor can be started normally, the refrigerant is ensured to be in the circulating loop, and the effective refrigeration cycle is ensured.

[0170] The oil return assembly of the application is arranged in the outer cylinder space of the new type of liquid storage tank, and a low-density floating ball and a matched hose are used to collect the oil-rich liquid in the upper layer of the liquid storage tank and send it to the heating component under suitable operating conditions, the heating component makes the refrigerant in the oil-rich liquid gasify and separate out the lubricating oil which is returned to the gas-liquid separator and waits to be pumped back by the compressor.

[0171] The application aims at the stratification of the oil liquid in the liquid storage tank caused by the fluorine pump refrigeration operation, and ensures that the stratified lubricating oil can be returned to the compressor oil pool in time when the compressor is started, so that the reliable operation of the compression refrigeration is ensured, and the problems of the recovery control and separation of the lubricating oil returned to the compressor oil pool when the oil liquid in the liquid storage tank is stratified under low-temperature conditions of the fluorine pump compression double-circulation refrigeration unit are solved.

[0172] In some embodiments,

[0173] The heating component includes fins and / or fins arranged on the partial pipe section of the oil return pipeline 206, so that the partial pipe section forms a finned pipe and / or finned pipe 29, which is arranged at the return air outlet of the evaporator 5.

[0174] This is the preferred structure of the heating component of the present application, that is, the heating component includes fins and / or fins, thereby forming a finned pipe and / or finned pipe on the oil return pipeline, so that the heat exchange can be enhanced, especially when the finned pipe and / or finned pipe 29 is arranged at the return air outlet of the evaporator 5, the relatively hot gas of the evaporator return air can be used to heat the mixture of refrigerant and oil in the oil return pipeline, so as to evaporate the refrigerant, achieve the purpose of further separating the refrigerant and the oil, improve the separation purity of the lubricating oil, and improve the oil return efficiency of the compressor.

[0175] In some embodiments,

[0176] The finned pipe and / or finned pipe 29 is arranged outside and / or inside the evaporator 5, and when the finned pipe and / or finned pipe 29 is arranged inside the evaporator 5, the finned pipe and / or finned pipe 29 is integrally formed with the heat exchange pipe of the evaporator 5.

[0177] The finned pipe and / or finned pipe of the present application can be located outside and / or inside the evaporator, which are two different arrangements of the finned pipe and / or finned pipe of the present application, as long as they are located at the return air outlet of the evaporator, and effectively utilize the relatively high temperature gas at the return air outlet to heat the oil return pipeline. When the finned pipe and / or finned pipe of the present application is arranged inside the evaporator, it is preferred to be integrally formed with the heat exchange pipe of the evaporator, so as to realize the integrated manufacturing, but the refrigerant in the heat exchange pipe of the evaporator does not mix with the fluid in the finned pipe and / or finned pipe, and is not communicated.

[0178] The present application preferably provides a heating component arranged on the oil return pipeline 206, which is preferably arranged at the return air outlet of the evaporator, so as to fully utilize the heat of the indoor hot air to heat the oil-rich liquid inside the evaporator heating component, so that the refrigerant in the oil-rich liquid evaporates and vaporizes, thereby separating the lubricating oil, as shown in Figure 2 The heating component can be heat exchange fins or fins arranged on the outer surface of the oil return pipeline, that is, a finned pipe and / or finned pipe is arranged in series on the oil return pipeline, and the finned pipe and / or finned pipe is arranged in the return air passage; the finned pipe and / or finned pipe can be integrally formed with the evaporator, that is, a separate branch is arranged on the finned pipe heat exchanger type evaporator for connecting the oil return pipeline, that is, the oil return port of the gas-liquid separator is connected to one section of the branch, and the other end of the branch is connected to the liquid return pipe of the liquid storage tank, as shown in Figure 1 .

[0179] In some embodiments,

[0180] The gas-liquid separator 30 is further included, which is arranged at the suction end of the compressor 1 and communicates with the suction end, and the other end of the oil return pipeline 206 communicates with the inside of the gas-liquid separator 30, and the control valve 28 is an electromagnetic valve.

[0181] The gas-liquid separator is preferably arranged at the suction end of the compressor, the oil return pipeline communicates with the inside of the gas-liquid separator, the separated lubricating oil is guided into the gas-liquid separator, and the fluid in the gas-liquid separator is sucked when the compressor starts, so that the lubricating oil is guided back to the compressor, and the control valve of the application preferably adopts an electromagnetic valve to realize accurate control, and is further preferably a de-energized normally closed electromagnetic valve.

[0182] The fluorine pump compression double-cycle refrigeration unit further preferably includes a gas-liquid separator 30 arranged between the top outlet of the gas collector 104 of the evaporator and the suction port of the compressor 1.

[0183] The gas-liquid separator 30 preferably further has a lubricating oil return port connected to the inside of the bottom end of the liquid storage tank 2 through an oil return pipeline 206.

[0184] The application further provides a control method of the refrigeration system with the refrigerant redundancy adjustment function as described above, which comprises:

[0185] A detection step of detecting whether it is during the compressor shutdown or the fluorine pump shutdown and detecting the temperature of the liquid storage tank 2;

[0186] A judgment step of judging the relationship between the temperature of the liquid storage tank 2 and the preset temperature T0;

[0187] A control step of controlling the control valve 28 to be opened when it is during the compressor shutdown or the fluorine pump shutdown and the temperature of the liquid storage tank 2 is less than T0 for more than t0 time, wherein t0 is a preset time.

[0188] The application controls the on-off of the oil return component to make the oil-rich liquid in the upper layer of the low-temperature liquid storage tank enter the heating component to separate the refrigerant and the lubricating oil by using hot air when it is during the compressor shutdown or the fluorine pump shutdown and the temperature of the liquid storage tank 2 is less than T0 for more than t0 time (this state is most likely to cause oil-refrigerant stratification, so the purity of the separated oil is higher, and the efficiency is higher), the system control is simple and reliable, does not affect the reliability of the compression refrigeration or the fluorine pump refrigeration operation, and the separation and recovery of the lubricating oil in the liquid storage tank under low-temperature conditions are safe and reliable.

[0189] In some embodiments,

[0190] The control step controls the control valve 28 to be opened for a time duration t1, and after the time t1, the control valve 28 is closed, and the indoor fan 14 opposite to the evaporator 5 is opened for a running time t2; the control valve 28 and the indoor fan 14 are sequentially opened again under the condition that the temperature of the liquid storage tank meets the condition next time, wherein t1 is a first preset time, and t2 is a second preset time.

[0191] The oil return control principle of the present application is described as follows:

[0192] Under low temperature conditions, the refrigerant liquid and the lubricating oil in the liquid storage tank will be stratified, the low-density lubricating oil floats on the high-density refrigerant liquid, so that the upper layer of the liquid storage tank is rich in oil; the float ball and the hose are made of low-density materials, and the liquid inlet of the float ball is connected to the hose, and the density of the float ball and the hose is lower than the density of the lubricating oil at the highest temperature of the unit design operation (the density of the lubricating oil is usually negatively correlated with the temperature);

[0193] 1) During the shutdown of the compressor or the fluorine pump, if the temperature of the liquid storage tank is detected to be ≤T0 and the duration is t0 or more (the condition most prone to oil liquid stratification), the opening time of the electromagnetic valve is t1, so that the rich oil liquid in the upper layer of the liquid storage tank is quantitatively (because the opening time t1 of the electromagnetic valve is fixed) under the action of gravity into and fills the oil return pipeline;

[0194] 2) Close the electromagnetic valve, open the indoor fan for a duration t2, use the hot air in the room to heat and evaporate the refrigerant liquid in the heating component into gas, and the lubricating oil is separated and left in the heating component;

[0195] 3) The electromagnetic valve is opened under the condition that the next condition is met, the oil liquid continues to enter the oil return pipeline, and the separated and left lubricating oil in the heating component is pushed into the gas-liquid separator, and the lubricating oil entering the gas-liquid separator waits to be sucked back to the oil pool of the compressor after the compressor starts.

[0196] The present application continuously collects and stores the separated lubricating oil in the gas-liquid separator under the fluorine pump refrigeration mode (for example, the fluorine pump temporarily stops for oil return), which does not affect the reliable operation of the fluorine pump refrigeration mode, and the more and more lubricating oil stored in the gas-liquid separator waits for the start of the compressor operation, which can effectively guarantee the start and operation reliability of the compressor; under the fluorine pump refrigeration mode, the lubricating oil flowing in the system is less and less, so that the refrigerant liquid flowing into the heating component after the electromagnetic valve is opened will be fully heated and vaporized to enter the condenser for cooling and liquefaction and return to the liquid storage tank, and the refrigerant liquid will not accumulate in the gas-liquid separator, so that the oil return control of the present application is safe and reliable, and can fully guarantee the oil return effect of the compressor.

[0197] The above merely describes preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application. The above merely describes preferred embodiments of the present application and is not used to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A refrigeration system with refrigerant redundancy adjustment function, characterized in that: It comprises: a fluorine pump (10), a liquid storage tank (2), an evaporator (5) and a balance pipe (103), the liquid storage tank (2) comprises an outer cylinder (6) and an inner cylinder (7), the inner cylinder (7) is located in the inner periphery of the outer cylinder (6), and a first communication hole (9) is arranged on the cylinder wall of the inner cylinder (7) to enable the inside of the inner cylinder (7) to communicate with the inside of the outer cylinder (6), the fluorine pump (10) is communicated between the inside of the outer cylinder (6) and the evaporator (5), one end of the balance pipe (103) is communicated to the inside upper end of the inner cylinder (7), the other end of the balance pipe (103) is communicated to the outlet end of the evaporator (5), and in the fluorine pump mode, the balance pipe (103) can introduce fluid from the outlet end of the evaporator (5) to the inside of the inner cylinder (7) to enable at least part of the liquid in the inner cylinder (7) to be pressed into the outer cylinder (6) through the first communication hole (9) to increase the liquid level height in the outer cylinder (6); It also comprises a compressor (1) and an oil return assembly which can recover the oil-containing mixture in the liquid storage tank (2) and deliver the separated oil to the compressor (1); It also comprises a condenser (3) and a liquid inlet pipe (101), one end of the liquid inlet pipe (101) is communicated with the condenser (3), the other end is communicated with the inside top end of the outer cylinder (6) of the liquid storage tank (2) to enable the heat-exchanged refrigerant in the condenser (3) to be introduced into the liquid storage tank (2).

2. The refrigeration system with refrigerant redundancy adjustment function according to claim 1, characterized in that: A one-way valve C (12) is arranged on the balance pipe (103), and the one-way valve C (12) only allows fluid to flow from the outlet end of the evaporator (5) to the inner cylinder (7) in the balance pipe (103).

3. The refrigeration system with refrigerant redundancy adjustment function according to claim 1, characterized in that: It also comprises a floating component (8) arranged in the inside of the inner cylinder (7), and the floating component (8) floats in the liquid in the inner cylinder (7) to rise or fall integrally with the liquid level height, a lower limit plate (18) is arranged below the floating component (8), a second communication hole (19) is further arranged on the lower limit plate (18), the second communication hole (19) penetrates the upper and lower end faces of the lower limit plate (18), and the liquid below the lower limit plate (18) can enter above the lower limit plate (18) through the second communication hole (19) and float the floating component (8) up, when the liquid height above the lower limit plate (18) drops to the height of the lower limit plate (18), the floating component (8) drops to the second communication hole (19) and blocks the second communication hole (19).

4. The refrigeration system with refrigerant redundancy adjustment function according to claim 3, characterized in that: The first communication hole (9) is located below the height of the lower limit plate (18); the second communication hole (19) is arranged opposite to the floating component (8) in the vertical direction, and the lower end surface area of the floating component (8) is greater than the cross-sectional area of the second communication hole (19); The lower limit plate (18) is fixedly arranged on the inner wall of the inner cylinder (7), the outer peripheral wall of the lower limit plate (18) is sealingly fixed to the inner peripheral wall of the inner cylinder (7), the lower limit plate (18) can limit the downward movement of the floating component (8), and the lower limit plate (18) is a single-hole plate, that is, the number of the second communication hole (19) is one.

5. The refrigeration system with refrigerant redundancy adjustment function according to claim 3, characterized in that: The lower end of the floating component (8) is further connected with a lower connecting rod (20), the lower connecting rod (20) is arranged in the second communication hole (19) and can move up and down in the second communication hole (19), the outer peripheral cross-sectional area of the lower connecting rod (20) is smaller than the cross-sectional area of the second communication hole (19), and the outer peripheral cross-sectional area of the lower connecting rod (20) is smaller than the lower end surface area of the floating component (8).

6. The refrigeration system with refrigerant redundancy adjustment function according to any one of claims 3-5, characterized in that: An upper limit plate (21) is further arranged above the floating component (8), the upper limit plate (21) is fixedly arranged on the inner wall of the inner cylinder (7), and the upper limit plate (21) can limit the upward movement of the floating component (8); The upper limit plate (21) is provided with a third communication hole (22), the third communication hole (22) penetrates the upper end surface and the lower end surface of the upper limit plate (21), so as to communicate the space above the upper limit plate (21) with the space below the upper limit plate (21), so that the liquid and / or gas below the upper limit plate (21) can enter the space above the upper limit plate (21) through the third communication hole (22), and the liquid and / or gas above the upper limit plate (21) can also enter the space below the upper limit plate (21) through the third communication hole (22).

7. The refrigeration system with refrigerant redundancy adjustment function according to claim 6, characterized in that: The upper limit plate (21) is a multi-hole plate, and the third communication hole (22) is a plurality of third communication holes (22), and the plurality of third communication holes (22) are distributed on the upper limit plate (21) at intervals; The upper end of the floating component (8) is further connected with an upper connecting rod (23), the upper connecting rod (23) is arranged in the third communication hole (22) and can move up and down in the third communication hole (22), and the outer peripheral cross-sectional area of the upper connecting rod (23) is smaller than the cross-sectional area of the third communication hole (22).

8. The refrigeration system with refrigerant redundancy adjustment function according to claim 7, characterized in that: The floating component (8) is a float, comprising an upper structure (24) and a lower structure (25), the lower end of the upper structure (24) is connected with the upper end of the lower structure (25), the upper structure (24) is a conical structure, the lower structure (25) is a column structure, when having an upper connecting rod (23) and a lower connecting rod (20) at the same time, the upper end of the upper structure (24) is connected with the lower end of the upper connecting rod (23), the outer peripheral cross-sectional area of the upper end of the upper structure (24) is equal to the outer peripheral cross-sectional area of the lower end of the upper connecting rod (23), the lower end of the lower structure (25) is connected with the upper end of the lower connecting rod (20), the outer peripheral cross-sectional area of the lower end of the lower structure (25) is greater than the outer peripheral cross-sectional area of the upper end of the lower connecting rod (20).

9. The refrigeration system with refrigerant redundancy adjustment function according to claim 1, characterized in that: The evaporator (5) comprises a collecting pipe (104) located at the outlet end of the evaporator (5), and the other end of the balance pipe (103) is communicated to the inner bottom end of the collecting pipe (104).

10. The refrigeration system with refrigerant redundancy adjustment function according to claim 1, characterized in that: Further comprising a liquid outlet pipe (102), one end of the liquid outlet pipe (102) is communicated to the inner bottom end of the outer cylinder (6) of the liquid storage tank (2), and the other end is communicated to one end of the fluorine pump (10).

11. The refrigeration system with refrigerant redundancy adjustment function according to claim 10, characterized in that: Further comprising a first pipeline (201), a second pipeline (202), a third pipeline (203), a fourth pipeline (204), a fifth pipeline (205), a throttling valve (4), a one-way valve A (11), a one-way valve B (15) and an oil separator (13), the other end of the fluorine pump (10) is communicated to one end of the evaporator (5) through the first pipeline (201), the throttling valve (4) is arranged on the first pipeline (201), one end of the second pipeline (202) is communicated to the liquid outlet pipe (102), and the other end is communicated to a position between the fluorine pump (10) and the throttling valve (4) on the first pipeline (201), and the one-way valve A (11) allowing fluid to flow only from the liquid outlet pipe (102) to the first pipeline (201) is arranged on the second pipeline (202); the other end of the evaporator (5) is communicated to the third pipeline (203), the third pipeline (203) is communicated to the suction end of the compressor (1) through the fourth pipeline (204), the third pipeline (203) is also communicated to the exhaust end of the compressor (1) through the fifth pipeline (205), the one-way valve B (15) allowing refrigerant fluid to flow only from the suction end to the exhaust end of the compressor (1) is arranged on the fifth pipeline (205), and the oil separator (13) is arranged between the exhaust end of the compressor (1) and the condenser (3).

12. The refrigeration system with the refrigerant redundancy adjustment function according to claim 11, characterized in that: the other end of the balance pipe (103) is communicated to the third pipeline (203) or to the fifth pipeline (205); or the evaporator (5) comprises a gas collecting pipe (104) located at the outlet end of the evaporator (5), and the other end of the balance pipe (103) is communicated to the inner bottom end of the gas collecting pipe (104), and the inner top end of the gas collecting pipe (104) is communicated to the third pipeline (203).

13. The refrigeration system with the refrigerant redundancy adjustment function according to claim 1, characterized in that: the oil return assembly comprises a floating body (26), a hose (27) and an oil return pipeline (206), the floating body (26) is arranged inside the outer cylinder (6), and the floating body (26) can float in the liquid in the outer cylinder (6) to rise or fall integrally with the liquid level, a liquid suction port is arranged on the floating body (26) to suck the oil-containing mixture at the liquid surface, the upper end of the hose (27) is connected to the floating body (26) to rise and fall integrally with the floating body (26) to guide the oil-containing mixture sucked by the floating body (26) out, and the lower end of the hose (27) is communicated to one end of the oil return pipeline (206), and the oil return pipeline (206) extends out of the liquid storage tank (2) to guide the oil-containing mixture to the suction end of the compressor (1).

14. The refrigeration system with the refrigerant redundancy adjustment function according to claim 13, characterized in that: a control valve (28) is arranged on the oil return pipeline (206), and a heating component is arranged on the oil return pipeline (206), and the heating component can heat the mixture of refrigerant and oil in the oil return pipeline (206) to evaporate the refrigerant and separate the lubricating oil.

15. The refrigeration system with the refrigerant redundancy adjustment function according to claim 14, characterized in that: the heating component comprises fins and / or fins arranged on the part of the pipeline section of the oil return pipeline (206) to form a finned tube and / or finned tube (29), and the finned tube and / or finned tube (29) is arranged at the return air inlet of the evaporator (5).

16. The refrigeration system with the refrigerant redundancy adjustment function according to claim 15, characterized in that: the finned tube and / or finned tube (29) is arranged outside and / or inside the evaporator (5), and when the finned tube and / or finned tube (29) is arranged inside the evaporator (5), the finned tube and / or finned tube (29) is integrally formed with the heat exchange tube of the evaporator (5).

17. The refrigeration system with the refrigerant redundancy adjustment function according to claim 14, characterized in that: The application further comprises a gas-liquid separator (30) arranged at and communicated with the suction end of the compressor (1), and the other end of the oil return pipeline (206) is communicated with the inside of the gas-liquid separator (30), and the control valve (28) is an electromagnetic valve.

18. A control method of a refrigeration system having a refrigerant redundancy amount adjusting function according to any one of claims 14 to 17, characterized by: The application further comprises: a detection step of detecting whether the compressor is in a shutdown period or the fluorine pump is in a shutdown period, and detecting the temperature of the liquid storage tank (2); a judgment step of judging the relationship between the temperature of the liquid storage tank (2) and a preset temperature T0; a control step of controlling the control valve (28) to be opened when the compressor is in the shutdown period or the fluorine pump is in the shutdown period, and the temperature of the liquid storage tank (2) is less than T0 for more than t0 time, wherein t0 is a preset time.

19. The control method according to claim 18, wherein: the control step controls the control valve (28) to be opened for t1 time, and then controls the control valve (28) to be closed, and controls the inner fan (14) opposite to the evaporator (5) to be opened and continuously operated for t2 time after the control valve (28) is opened for t1 time; and then the control valve (28) and the inner fan (14) are sequentially opened again under the condition that the temperature of the liquid storage tank meets the condition next time, wherein t1 is a first preset time, and t2 is a second preset time.

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