Liquid level detector, low-temperature circulation barrel assembly and control method of liquid level detector

Abstract

The invention provides a liquid level detector, a low-temperature circulation barrel assembly and a control method of the liquid level detector, and relates to the technical field of refrigeration. The liquid level detector comprises a liquid level detection pipe and a heating piece; the liquid level detection pipe is provided with an air inlet, a liquid inlet and an oil outlet which are arranged at intervals in the axial direction of the liquid level detection pipe, the position of the air inlet is higher than the positions of the liquid inlet and the oil outlet, and the position of the liquid inlet is higher than the position of the oil outlet; the heating piece is connected to the liquid level detection pipe and used for heating the liquid level detection pipe; wherein the liquid level detection pipe has a liquid detection state and a cleaning state; in the liquid measuring state, the air inlet and the liquid inlet are configured to be in an open state, and the oil discharge outlet and the heating piece are configured to be in a closed state; and in the cleaning state, the air inlet and the liquid inlet are configured to be in a closed state, and the oil outlet and the heating piece are configured to be in an open state. The liquid level detection pipe is heated through the heating piece, so that the emulsified refrigerant oil is melted and discharged out of the liquid level detection pipe, the refrigerant oil is cleaned, and the detection accuracy of the liquid level detector is ensured.

Description

Technical Field

[0001] The present application relates to the field of refrigeration technology, and in particular to a liquid level detector, a low-temperature circulation barrel assembly, and a control method for the liquid level detector. Background Art

[0002] The low-temperature circulation barrel of the existing cascade system is used to store low-temperature liquid refrigerant. In the refrigeration system, there is refrigeration oil that is soluble with the liquid refrigerant. During long-term low-temperature operation, part of the refrigeration oil combines with the liquid refrigerant and emulsifies into emulsified refrigeration oil, which sticks to the inner wall of the container and components.

[0003] Magnetic flap level gauges are often used to detect the liquid level in a circulating barrel. Some of the liquid in the circulating barrel will enter the magnetic flap level gauge. After long-term use, the tube of the magnetic flap level gauge will also be attached with the above-mentioned emulsion of refrigeration oil, which reduces the space in the tube, causing the liquid level display to lag or be inaccurate. In addition, the high viscosity of the emulsion of refrigeration oil will affect the floating ball in the magnetic flap level gauge. In severe cases, the float will be stuck and unable to move, and the machine must be stopped for manual cleaning. When cleaning, it is necessary to stop the machine and perform high-altitude operations, which is time-consuming and labor-intensive, and the cleaning effect is limited. Summary of the invention

[0004] Based on this, it is necessary to provide a liquid level detector, a low-temperature circulation barrel assembly and a control method for the liquid level detector, which can realize the cleaning of the refrigeration oil without manual operation, so as to save manpower and ensure the cleaning effect.

[0005] A liquid level detector, comprising a liquid level detection tube and a heating element; the liquid level detection tube is constructed with an air inlet, a liquid inlet and an oil drain port spaced apart along its own axial direction, the position of the air inlet is higher than the positions of the liquid inlet and the oil drain port, and the position of the liquid inlet is higher than the position of the oil drain port; the heating element is connected to the liquid level detection tube, and the heating element is used to heat the liquid level detection tube; wherein the liquid level detector has a liquid measuring state and a cleaning state; in the liquid measuring state, the air inlet and the liquid inlet are configured to be in an open state, and the oil drain port and the heating element are configured to be in a closed state; in the cleaning state, the air inlet and the liquid inlet are configured to be in a closed state, and the oil drain port and the heating element are configured to be in an open state.

[0006] It is understandable that in the liquid measuring state, the liquid level detector can allow the gas and liquid in the circulation barrel to enter the liquid level detection tube through the air inlet and the liquid inlet, and automatically reach a gas-liquid balance, thereby obtaining the liquid level height of the circulation barrel. After the liquid level detector is used repeatedly, it needs to be cleaned. In the cleaning state, the air inlet and the liquid inlet are closed, and after the refrigerant is emptied, the heating element can heat the liquid level detection tube, so that the emulsion refrigerant oil on the tube wall of the liquid level detection tube can melt at high temperature, and under the action of gravity, it flows out from the oil discharge port, thereby cleaning the refrigerant oil in the liquid level detector, which is conducive to ensuring the accuracy of the liquid level detector detection.

[0007] In one of the embodiments, the heating element is attached to the outer wall of at least a portion of the liquid level detection tube below the air inlet; the heating element is configured as a heating belt, and the heating belt is spirally wound around the liquid level detection tube.

[0008] It is understandable that the heating element is attached to the tube wall so as to directly transfer heat to the inner side of the tube wall, which is conducive to improving the heating efficiency. The heating element is arranged as a heating belt, which is more convenient when attached and is conducive to reducing the heat transfer gap.

[0009] In one of the embodiments, along the axial direction of the liquid level detection tube, the length covered by the heating element accounts for 30% to 70% of the length of the liquid level detection tube.

[0010] It is understandable that such a setting can ensure that the refrigeration oil is fully heated while reducing the substantial pressure increase caused by heating, especially avoiding excessive heating temperature that causes a substantial increase in pressure in the circulation barrel, thereby ensuring safety.

[0011] In one of the embodiments, a gas port is configured at one end of the liquid level detection tube away from the oil drain port; the liquid level detector also includes an air blowing assembly, the air blowing assembly includes a second air inlet pipe and a second air inlet valve, the second air inlet valve is installed on the second air inlet pipe; the second air inlet pipe is connected to the gas port.

[0012] It is understandable that after the refrigeration oil is melted and initially discharged, the gas is blown from the gas port into the liquid level detection tube through the blowing assembly to further discharge the remaining refrigeration oil and improve the cleaning effect. The second air inlet valve in the blowing assembly can control the opening and closing of the second air inlet pipe to control the entry of gas.

[0013] In one embodiment, the inner diameter of the second air inlet pipe is 5% to 10% of the inner diameter of the liquid level detection pipe.

[0014] It can be understood that such a configuration can increase the gas flow rate in the second air inlet pipe, which is beneficial for the rapid input of gas into the liquid level detection tube.

[0015] In one embodiment, the liquid level detector includes an exhaust pipeline, the exhaust pipeline includes an exhaust pipe and an exhaust valve, the exhaust pipe is connected to the gas port, and the exhaust valve is installed on the exhaust pipe; the exhaust pipeline and the blowing assembly are connected in parallel; the exhaust valve is configured to adjust opening and closing in response to the working condition of the heating element.

[0016] It can be understood that the exhaust pipe is opened before the heating element is heated to reduce the pressure in the liquid level detection tube. The liquid refrigerant vaporizes into gaseous refrigerant as the pressure decreases and flows out of the exhaust pipe to reduce the impact of the liquid refrigerant on the heating of the refrigeration oil and promote the efficiency of the heating of the refrigeration oil.

[0017] In one embodiment, the liquid level detector also includes an oil drain pipeline connected to the oil drain port, the oil drain pipeline includes an oil drain pipe and an oil drain valve, the oil drain pipe is communicated with the oil drain port, the oil drain valve is connected to the oil drain pipe, and the oil drain valve is configured to adjust opening and closing in response to switching between the liquid measuring state and the cleaning state.

[0018] It can be understood that the refrigeration oil is discharged through the oil drain pipeline, and the oil drain pipeline is disconnected from the liquid level detection tube in the liquid measuring state, and is connected to the liquid level detection tube in the cleaning state.

[0019] In one of the embodiments, the liquid level detector also includes an air intake pipeline, the air intake pipeline includes a first air intake pipe and a first air intake valve, the first air intake valve is installed on the first air intake pipe, and the first air intake pipe is connected to the air inlet; the liquid level detector also includes a liquid inlet pipeline; the liquid inlet pipeline includes a liquid inlet pipe and a liquid inlet valve, the liquid inlet valve is installed on the liquid inlet pipe, and the liquid inlet pipe is connected to the liquid inlet; the first air intake valve and the liquid inlet valve are configured to adjust opening and closing in response to switching between the liquid measuring state and the cleaning state.

[0020] It is understandable that the air inlet pipeline can transport the gas in the circulation barrel to the liquid level detection tube, and the liquid inlet pipeline can transport the liquid in the circulation barrel to the liquid level detection tube, so as to detect the liquid level of the circulation barrel. In the cleaning state, by disconnecting the air inlet pipeline and the liquid inlet pipeline, the gas and liquid in the circulation barrel no longer enter, so as to clean the inside of the liquid level detection tube.

[0021] A low-temperature circulation barrel assembly comprises a circulation barrel and the above-mentioned liquid level detector; the circulation barrel comprises a first air outlet, a second air outlet and a liquid outlet which are arranged at intervals, the heights of the first air outlet and the second air outlet are respectively higher than the liquid outlet, and the height of the second air outlet is not lower than the height of the first air outlet; the air inlet pipeline is connected between the air inlet and the first air outlet; the liquid inlet pipeline is connected between the liquid inlet and the liquid outlet; the blowing assembly is connected between the gas port and the second air outlet.

[0022] It is understandable that, in this arrangement, the gaseous refrigerant can flow from the first gas outlet of the circulation barrel through the gas inlet pipeline into the liquid level detection tube, and the liquid refrigerant can flow from the liquid outlet of the circulation barrel through the liquid inlet assembly into the liquid level detection tube, so as to detect the liquid level height in the circulation barrel. The blowing assembly can blow the gas in the circulation barrel into the liquid level detection tube through the second gas outlet, so as to discharge the remaining refrigerant oil in a clean state.

[0023] A control method for a liquid level detector, the control method for the liquid level detector is based on the above-mentioned low-temperature circulation barrel assembly; the control method for the liquid level detector comprises the following steps: emptying the refrigerant in a liquid level detection tube; heating the liquid level detection tube with a heating element; and when the refrigerant oil in the liquid level detection tube is in a molten state, opening an oil drain port to discharge the refrigerant oil.

[0024] It is understandable that the gas and liquid in the liquid level detection tube are discharged so that the heating element can quickly heat the refrigeration oil on the wall of the liquid level detection tube to melt the refrigeration oil and avoid the liquid hindering the melting of the refrigeration oil. In this way, the liquid level detection tube is cleaned, which is beneficial to the subsequent detection of the liquid level by the liquid level detection tube and ensures the accuracy of the detection.

[0025] In one of the embodiments, after the refrigerant oil is discharged, the control method of the liquid level detector further includes: blowing gas into the liquid level detection tube, and the remaining refrigerant oil is discharged from the oil drain port under the blowing of the gas; wherein, blowing gas into the liquid level detection tube includes: blowing gas into the liquid level detection tube at a first interval, with a frequency of not less than n times, n≥3, n∈N; or continuously blowing gas into the liquid level detection tube.

[0026] It is understandable that after most of the oil is discharged, the remaining oil can be discharged by blowing in gas, thereby improving the oil removal efficiency. The intermittent blowing method is more flexible in the process of removing the oil, and the time and number of intermittent blowing can be controlled according to the amount of remaining oil. The continuous blowing method can continuously drive the oil to be discharged through gas, thereby improving the oil removal efficiency.

[0027] In one of the embodiments, before emptying the refrigerant in the liquid level detection tube, and / or after the remaining refrigerant oil is discharged from the oil drain port under the blowing of the gas, the control method of the liquid level detector also includes: the first air inlet valve and the liquid inlet valve are opened, and the liquid level detection tube is connected to the circulation barrel; the oil drain valve and the heating element are closed; and the liquid level height of the circulation barrel is obtained after gas-liquid equilibrium is reached in the liquid level detection tube.

[0028] It can be understood that before and after the oil is drained, the liquid level detector is in the liquid measuring state, and the gas and liquid in the circulation barrel are allowed to pass into the liquid level detection tube by opening the first air inlet valve and the liquid inlet valve, so as to facilitate the testing of the circulation barrel. The oil drain valve and the heating element are closed to ensure the stability of the gas and liquid composition in the liquid level detection tube.

[0029] In one embodiment, the emptying of the refrigerant in the liquid level detection tube includes: opening the exhaust pipe to reduce the pressure in the liquid level detection tube, and the liquid refrigerant in the liquid level detection tube can be vaporized into gas as the pressure decreases, so as to be discharged from the gas port.

[0030] It can be understood that the provision of the exhaust pipe facilitates the discharge of the vaporized refrigerant, thereby facilitating the recovery and utilization of the refrigerant. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the conventional technology, the drawings required for use in the embodiments or the conventional technology descriptions are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 This is a schematic diagram of the structure of the liquid level detector provided in this application.

[0033] : Illustrations: 1000, low-temperature circulation barrel assembly; 100, liquid level detector; 200, circulation barrel; 2001, first air outlet; 2002, second air outlet; 2003, liquid outlet; 10, liquid level detection tube; 101, air inlet; 102, liquid inlet; 103, oil drain; 104, gas port; 20, heating element; 30, blowing assembly; 31, second air inlet pipe; 32, combination valve; 321, second air inlet valve; 322, filter; 323, stop valve; 40, exhaust pipeline; 41, exhaust pipe; 42, exhaust valve; 50, oil drain pipeline; 51, oil drain pipe; 52, oil drain valve; 60, air intake pipeline; 61, first air intake pipe; 62, first air intake valve; 70, liquid inlet pipeline; 71, liquid inlet pipe; 72, liquid inlet valve; 80, float. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0035] It should be noted that when a component is referred to as being "fixed to" or "disposed on" another component, it may be directly on the other component or there may also be a central component. When a component is considered to be "connected to" another component, it may be directly connected to the other component or there may be a central component at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used in the specification of this application are for illustrative purposes only and do not represent the only implementation method.

[0036] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0037] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is directly in contact with the second feature, or the first feature and the second feature are indirectly in contact through an intermediate medium. Moreover, a first feature being “above”, “above” or “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below” or “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0038] Unless otherwise defined, all technical and scientific terms used in the specification of this application have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used in the specification of this application includes any and all combinations of one or more related listed items.

[0039] See also Figure 1The present application provides a liquid level detector 100, which includes a liquid level detection tube 10 and a heating element 20; the liquid level detection tube 10 is constructed with an air inlet 101, a liquid inlet 102 and an oil drain port 103 arranged at intervals along its own axial direction, the position of the air inlet 101 is higher than the positions of the liquid inlet 102 and the oil drain port 103, and the position of the liquid inlet 102 is higher than the position of the oil drain port 103; the heating element 20 is connected to the liquid level detection tube 10, and the heating element 20 is used to heat the liquid level detection tube 10; wherein the liquid level detector 100 has a liquid measuring state and a cleaning state; in the liquid measuring state, the air inlet 101 and the liquid inlet 102 are configured to be in an open state, and the oil drain port 103 and the heating element 20 are configured to be in a closed state; in the cleaning state, the air inlet 101 and the liquid inlet 102 are configured to be in a closed state, and the oil drain port 103 and the heating element 20 are configured to be in an open state.

[0040] It is understandable that the liquid level detection tube 10 can detect the liquid level in the circulation barrel 200, so as to adjust the liquid capacity in the circulation barrel 200 in real time, so that the liquid capacity in the circulation barrel 200 meets the requirements of specific working conditions. Since the circulation barrel 200 mainly stores refrigerant, and the refrigerant contains refrigeration oil, part of the refrigeration oil combines with the refrigerant and emulsifies into emulsion refrigeration oil, which sticks to the inner tube wall of the liquid level detection tube 10, the liquid level detection tube 10 is provided with a cleaning state to remove the refrigeration oil stuck to the tube wall, so as to improve the detection accuracy of the liquid level detection tube 10.

[0041] like Figure 1 As shown, specifically, in the liquid measuring state, the air inlet 101 and the liquid inlet 102 are opened, the heating element 20 and the oil drain port 103 are in the closed state, the gas in the circulation barrel 200 enters the liquid level detection tube 10 from the air inlet 101, and the liquid in the circulation barrel 200 enters the liquid level detection tube 10 from the liquid inlet 102. The air pressure in the circulation barrel 200 is consistent with the air pressure in the liquid level detection tube 10, and the liquid pressure in the circulation barrel 200 is consistent with the liquid pressure in the liquid level detection tube 10. Therefore, after the gas and liquid in the liquid level detection tube 10 reach a balanced state, the liquid level height of the liquid level detection tube 10 is consistent with the liquid level height in the circulation barrel 200, thereby the liquid level height in the circulation barrel 200 can be obtained.

[0042] Further, such as Figure 1 As shown, in the cleaning state, the air inlet 101 and the liquid inlet 102 are closed, and the heating element 20 and the oil drain port 103 are opened to prevent the liquid in the circulation barrel 200 from leaking from the oil drain port 103 after passing through the liquid inlet 102. The heating element 20 can heat the liquid level detection tube 10 to melt the refrigeration oil attached to the wall of the liquid level detection tube 10, and the melted refrigeration oil can be discharged from the oil drain port 103, thereby achieving the cleaning of the liquid level detection tube 10 and ensuring the accuracy of the liquid level detection result of the liquid level detector 100.

[0043] For ease of explanation, first, the structure related to liquid measurement is further explained.

[0044] like Figure 1 As shown, in some embodiments, the liquid level detector 100 further includes an air inlet pipeline 60 and a liquid inlet pipeline 70, the air inlet pipeline 60 is connected to the air inlet 101, and the liquid inlet pipeline 70 is connected to the liquid inlet 102; the air inlet pipeline 60 and the liquid inlet pipeline 70 are configured to adjust the on-off in response to the switching between the liquid measuring state and the cleaning state. In this way, the air inlet pipeline 60 is arranged so as to facilitate the input of the gas in the circulation barrel 200 into the liquid level detection tube 10, and the liquid inlet pipeline 70 is arranged so as to facilitate the input of the liquid in the circulation barrel 200 into the liquid level detection tube 10. In the liquid measuring state, the air inlet pipeline 60 and the liquid inlet pipeline 70 are respectively connected to the liquid level detection tube 10; in the cleaning state, the air inlet pipeline 60 and the liquid inlet pipeline 70 are respectively disconnected from the liquid level detection tube 10.

[0045] like Figure 1 As shown, in a specific embodiment, the air intake pipeline 60 includes a first air intake pipe 61 and a first air intake valve 62. The first air intake valve 62 is installed on the first air intake pipe 61. The first air intake pipe 61 is connected between the air intake port 101 and the first air outlet of the circulation barrel 200. In this way, the first air intake pipe 61 can realize the gas delivery, and the first air intake valve 62 can control the on-off of the first air intake pipe 61. Specifically, in the liquid measuring state, the first air intake valve 62 is opened to facilitate the communication between the first air intake pipe 61 and the liquid level detection tube 10 to realize gas delivery; in the cleaning state, the first air intake valve 62 is closed to disconnect the communication between the first air intake pipe 61 and the liquid level detection tube 10.

[0046] like Figure 1 As shown, in a further embodiment, the liquid inlet pipeline 70 includes a liquid inlet pipe 71 and a liquid inlet valve 72, the liquid inlet valve 72 is installed on the liquid inlet pipe 71, and the liquid inlet pipe 71 is connected between the liquid inlet port 102 and the liquid outlet of the circulation barrel 200. In this way, the liquid inlet pipe 71 can realize the liquid transportation, and the liquid inlet valve 72 can control the opening and closing of the liquid inlet pipe 71. Specifically, in the liquid measuring state, the liquid inlet valve 72 is opened to facilitate the liquid inlet pipe 71 to communicate with the liquid level detection tube 10 to realize liquid transportation; in the cleaning state, the liquid inlet valve 72 is closed to disconnect the liquid inlet pipe 71 from the liquid level detection tube 10.

[0047] like Figure 1 As shown, in a specific embodiment, a float 80 is provided in the liquid level detection tube 10, and the float 80 can be suspended on the liquid. The liquid level height value can be obtained by the suspension height of the float 80. The operation is simple, and the liquid level data can be directly observed.

[0048] Next, the cleaning-related structures are further described.

[0049] like Figure 1 As shown, in an optional embodiment, a gas port 104 is constructed at the other end of the liquid level detection tube 10 away from the oil drain port 103; the liquid level detector 100 includes an exhaust pipe 40, which is connected to the gas port 104; the exhaust pipe 40 is configured to adjust the on and off in response to the working condition of the heating element 20.

[0050] Specifically, before the heating element 20 is started, the exhaust pipe 40 is first connected to the gas port 104, so that the liquid level detection tube 10 is connected to the outside air through the exhaust pipe 40, and the pressure in the liquid level detection tube 10 is reduced. As the pressure decreases, the liquid refrigerant gradually vaporizes, but during the vaporization process, the pressure in the liquid level detection tube 10 is greater than the outside atmospheric pressure. The vaporized gaseous refrigerant is discharged from the exhaust pipe 40 through the pressure difference between the liquid level detection tube 10 and the outside atmosphere, that is, the liquid refrigerant is converted into gas and emptied to the outside. After the exhaust is completed, the heating element 20 is started to heat the liquid level detection tube 10, which can avoid the influence of the refrigerant in the liquid level detection tube 10 on the heating effect.

[0051] like Figure 1 As shown, in a specific embodiment, the exhaust pipeline 40 includes an exhaust pipe 41 and an exhaust valve 42, the exhaust pipe 41 is connected to the gas port 104, and the exhaust valve 42 is installed on the exhaust pipe 41 and can control the on and off of the exhaust pipe 41. Specifically, the exhaust valve 42 is opened to exhaust before the heating element 20 is turned on, and the exhaust valve 42 is closed after the exhaust is completed.

[0052] like Figure 1 As shown, in an optional embodiment, a heating element 20 is attached to the outer wall of at least part of the liquid level detection tube 10 located below the air inlet 101. In this way, the liquid level detection tube 10 is mainly filled with gas at the air inlet 101, and the amount of refrigeration oil attached is small or almost non-existent. The refrigeration oil is mainly located on the inner tube wall covered by the liquid refrigerant below the air inlet 101. Therefore, a heating element 20 is provided below the air inlet 101 so that the heating element 20 directly transfers heat to the tube wall of the liquid level detection tube 10, thereby realizing a large-scale heating of the refrigeration oil attached to the tube wall, which is beneficial to improving the heat transfer efficiency.

[0053] like Figure 1 As shown, in a further embodiment, along the axial direction of the liquid level detection tube 10, the length H covered by the heating element 20 accounts for 30% to 70% of the length L of the liquid level detection tube 10. In this way, the refrigeration oil can be fully heated to melt the refrigeration oil. At the same time, it can avoid a large increase in gas pressure due to excessive heating temperature, which is beneficial to protecting the structure of the liquid level detection tube 10 and the circulation barrel 200. Exemplarily, along the axial direction of the liquid level detection tube 10, the length H covered by the heating element 20 accounts for 30%, 50% or 70% of the length L of the liquid level detection tube 10.

[0054] like Figure 1 As shown, in a specific embodiment, the heating element 20 is configured as a heating belt, and the heating belt is spirally wound on the liquid level detection tube 10. With this configuration, the heating belt can be attached to the outer tube wall surface of the liquid level detection tube 10, and the gap between the heating belt and the liquid level detection tube 10 is small, which can reduce the air thermal resistance and help improve the heat transfer efficiency. At the same time, the spiral winding method is also convenient for assembling and fixing the heating belt at one time, and the operation is simple. In other embodiments, the heating element 20 can also be configured as a heating platform, and the bottom of the liquid level detection tube 10 is placed on the heating platform for heating, or the heating element 20 is configured as a heating plate, and the heating plate is attached to the tube wall of the liquid level detection tube 10 for heating, and it is only necessary to meet the heating.

[0055] like Figure 1 As shown, in an optional embodiment, the liquid level detector 100 further includes an oil drain pipe 50 connected to the oil drain port 103, and the oil drain pipe 50 is configured to adjust the on-off in response to the switching between the liquid measuring state and the cleaning state. Thus, in the cleaning state, the oil drain pipe 50 is in a connected state, and the heated and melted refrigerant oil can enter the oil drain pipe 50 from the oil drain port 103 and be output through the oil drain pipe 50, so as to facilitate the recycling of the refrigerant oil. In the liquid measuring state, the oil drain pipe 50 is in a disconnected state to avoid leakage of the refrigerant.

[0056] like Figure 1 As shown, in a specific embodiment, the oil drain pipeline 50 includes an oil drain pipe 51 and an oil drain valve 52. The oil drain pipe 51 is connected to the oil drain port 103. The oil drain valve 52 is connected to the oil drain pipe 51 to control the on-off of the oil drain pipe 51, that is, in the test state, the oil drain valve 52 is closed to disconnect the oil drain pipe 51, and in the cleaning state, the oil drain valve 52 is opened to connect the oil drain pipe 51.

[0057] like Figure 1 As shown, in an optional embodiment, the liquid level detector 100 further includes a blowing assembly 30, which is connected to the gas port 104 and is used to blow gas into the liquid level detection tube 10. In this way, after the refrigeration oil melts, the external gas is blown into the liquid level detection tube 10 through the blowing assembly 30, and the refrigeration oil in the liquid level detection tube 10 is further discharged from the oil discharge port 103 under the action of the gas pressure, which is conducive to improving the efficiency of oil discharge cleaning.

[0058] like Figure 1As shown, in a specific embodiment, the blowing assembly 30 includes a second air inlet pipe 31 and a second air inlet valve 321, and the second air inlet valve 321 is installed on the second air inlet pipe 31; the second air inlet pipe 31 is connected to the gas port 104. In this way, the gas can be blown into the liquid level detection tube 10 through the second air inlet pipe 31, and the second air inlet pipe 31 can be controlled to be on and off by the second air inlet valve 321. Specifically, when the heating element 20 is heated or after the heating element 20 is heated, the second air inlet valve 321 is opened to allow the gas to be blown into the liquid level detection tube 10; after the refrigeration oil is exhausted, the second air inlet valve 321 is closed to stop blowing into the liquid level detection tube 10. In actual application, the second air inlet pipe 31 of the blowing assembly 30 can be connected to the second air outlet of the circulation barrel 200 to transport the gas in the circulation barrel 200 to the liquid level detection tube 10.

[0059] like Figure 1 As shown, the exhaust pipeline 40 is connected in parallel with the blowing assembly 30. Specifically, the second air inlet pipe 31 in the blowing assembly 30 is directly connected to the gas port 104, and the exhaust pipe 41 in the exhaust pipeline 40 is connected to the second air inlet pipe 31. When exhausting, the gas in the liquid level detection tube 10 enters the exhaust pipe 41 through the second air inlet pipe 31 to achieve gas discharge.

[0060] like Figure 1 As shown, in a specific embodiment, the second air inlet valve 321 is set as a solenoid valve to quickly respond and adjust. Further, the blowing assembly 30 includes a combination valve 32, the combination valve 32 includes the second air inlet valve 321, and the combination valve 32 also includes a filter 322 and two stop valves 323 arranged at intervals, and the filter 322 and the second air inlet valve 321 are arranged between the two stop valves 323. In this way, the gas input into the liquid level detection tube 10 needs to be filtered by the filter 322 to reduce the entry of impurities. When the blowing assembly 30 is not working, the two stop valves 323 are closed to prevent the gas from continuously entering the second air inlet valve 321 and interfering with the second air inlet valve 321, so as to ensure that the second air inlet valve 321 can be tightened.

[0061] In a further embodiment, the inner diameter of the second air inlet pipe 31 is 5% to 10% of the inner diameter of the liquid level detection tube 10. This arrangement makes the diameter of the second air inlet pipe 31 smaller, which is conducive to throttling and reducing pressure, speeding up the gas flow rate, and increasing the amount of gas entering the liquid level detection tube 10 per unit time, which is conducive to improving the oil discharge efficiency. Exemplarily, the inner diameter of the second air inlet pipe 31 is 5%, 8% or 10% of the inner diameter of the liquid level detection tube 10.

[0062] The present application also provides a low-temperature circulation barrel assembly 1000, including a circulation barrel 200 and the above-mentioned liquid level detector 100; the circulation barrel 200 includes a first air outlet 2001, a second air outlet 2002 and a liquid outlet 2003 arranged at intervals, the heights of the first air outlet 2001 and the second air outlet 2002 are respectively higher than the liquid outlet 2003, and the height of the second air outlet 2002 is not lower than the height of the first air outlet 2001; the air inlet pipeline 60 of the liquid level detector 100 is connected between the air inlet 101 of the liquid level detection tube 10 and the first air outlet 2001 of the circulation barrel 200; the liquid inlet pipeline 70 is connected between the liquid inlet 102 of the liquid level detection tube 10 and the liquid outlet 2003 of the circulation barrel 200; the blowing assembly 30 is connected between the gas port 104 and the second air outlet 2002 of the circulation barrel 200.

[0063] In this configuration, the circulation barrel 200 is provided with a first gas outlet 2001 to facilitate the output of gaseous refrigerant into the liquid level detection tube 10, and a liquid outlet 2003 is provided to facilitate the output of liquid refrigerant into the liquid level detection tube 10, so that the gas-liquid two-phase refrigerant reaches equilibrium in the liquid level detection tube 10, and the liquid level detection is realized. At the same time, the second gas outlet 2002 is provided to facilitate the gaseous refrigerant in the circulation barrel 200 to be transported into the liquid level detection tube 10 when the liquid level detector 100 is in a clean state, so that the remaining refrigeration oil can be discharged by blowing the gas. The above-mentioned liquid inlet pipeline 70, gas inlet pipeline 60 and blowing assembly 30 respectively play the role of fluid transport and fluid on-off control.

[0064] Furthermore, the heights of the first gas outlet 2001 and the second gas outlet 2002 are respectively higher than the liquid outlet 2003, and the height of the second gas outlet 2002 is not lower than the height of the first gas outlet 2001. In this way, the gaseous refrigerant and the liquid refrigerant are automatically divided into upper and lower sides due to different densities. The arrangement of the first gas outlet 2001 and the second gas outlet 2002 is conducive to the output of the gaseous refrigerant, and the lower height of the liquid outlet 2003 is conducive to the output of the liquid refrigerant. At the same time, the height of the second gas outlet 2002 is not lower than the height of the first gas outlet 2001, so that the height of the second gas outlet 2002 is close to the gas port 104, shortening the distance between the second gas outlet 2002 and the gas port 104, and facilitating the pipe connection between the two.

[0065] The present application also provides a control method for a liquid level detector 100. Based on the above-mentioned liquid level detector 100, the control method for the liquid level detector 100 includes the following steps: emptying the refrigerant in the liquid level detection tube 10; heating the liquid level detection tube 10 with a heating element 20; and when the refrigerant oil in the liquid level detection tube 10 is in a molten state, opening the oil drain port 103 to discharge the refrigerant oil. In this way, by first emptying the refrigerant in the liquid level detection tube 10, the refrigerant oil is not disturbed by the refrigerant during heating, which is beneficial to improving the heating efficiency. By heating the liquid level detection tube 10, the refrigerant oil in the tube can be melted and discharged from the oil drain port 103 to clean the liquid level detection tube 10, which is beneficial to ensure the accuracy of the liquid measurement of the liquid level detection tube 10. In actual application, the cleaning frequency of the liquid level detector 100 can be set according to the actual working conditions, such as cleaning once a month, etc., which is not specifically limited here.

[0066] In a specific embodiment, emptying the refrigerant in the liquid level detection tube 10 includes: opening the exhaust pipe 40 to reduce the pressure in the liquid level detection tube 10, and the liquid refrigerant in the liquid level detection tube 10 can be vaporized into gas as the pressure decreases, and then discharged from the gas port 104. In this way, there is no need to set up an additional liquid discharge port, thereby reducing the setting of corresponding pipelines, making the structure more concise, and helping to reduce costs.

[0067] In a further embodiment, the liquid level detection tube 10 is heated mainly by the heating element 20 for a first heating time, and the range of the first heating time can be determined according to the size of the actual liquid level detection tube 10, the size of the circulation barrel, etc. In some embodiments, the first heating time ranges from 5 to 15 minutes, and illustratively, the first heating time can be set to 5 minutes, 10 minutes, or 15 minutes.

[0068] In a further embodiment, after the refrigerant oil is discharged, the control method of the liquid level detector 100 further includes: blowing gas into the liquid level detection tube 10, and the remaining refrigerant oil is discharged from the oil discharge port 103 under the blowing of the gas. Specifically, the gas is blown into the liquid level detection tube 10 through the above-mentioned blowing component 30. In this way, the remaining refrigerant oil can be driven to be discharged from the oil discharge port 103 by the flow of gas, thereby avoiding residue and improving the cleaning effect.

[0069] In some embodiments, blowing gas into the liquid level detection tube 10 includes: blowing gas into the liquid level detection tube 10 at first intervals, with a frequency of not less than n times, n≥3, n∈N. In this way, the intermittent time and frequency can be flexibly adjusted according to different working conditions by intermittent blowing. The exemplary first time range can be set to 3~10s, and the specific first time can be 3s, 5s or 10s. Exemplarily, the intermittent frequency can be 3 times, 5 times or 7 times, that is, n=3, 5 or 7. When there is too much residual refrigerant oil, the blowing assembly 30 can be kept in a normally open state to allow gas to be continuously blown into the liquid level detection tube 10.

[0070] In a further embodiment, before the refrigerant in the liquid level detection tube 10 is emptied, and / or after the remaining refrigerant oil is discharged from the oil drain port 103 under gas blowing, the liquid level detector 100 is in a liquid measuring state. At this time, the first air inlet valve 62 of the air inlet pipeline 60 and the liquid inlet valve 72 of the liquid inlet pipeline 70 are opened, the liquid level detection tube 10 is connected to the circulation barrel 200, the gas in the circulation barrel 200 enters the liquid level detection tube 10 through the air inlet pipeline 60, and the liquid in the circulation barrel 200 enters the liquid level detection tube 10 through the liquid inlet pipeline 70; at the same time, the oil drain valve 52 of the oil drain pipeline 50 and the heating element 20 are closed to avoid leakage of liquid refrigerant and gaseous refrigerant. After the gas-liquid equilibrium is reached in the liquid level detection tube 10, the liquid level height of the circulation barrel 200 can be obtained.

[0071] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the scope of patent protection of the present application shall be subject to the attached claims.

Claims

1. A liquid level detector, characterized in that: The liquid level detector comprises: The liquid level detection tube (10) is structured with an air inlet (101), a liquid inlet (102) and an oil discharge port (103) arranged at intervals along the axial direction thereof, the air inlet (101) being located higher than the liquid inlet (102) and the oil discharge port (103), and the liquid inlet (102) being located higher than the oil discharge port (103); A heating element (20) connected to the liquid level detection tube (10), the heating element (20) being used to heat the liquid level detection tube (10); The liquid level detector has a liquid measuring state and a cleaning state; in the liquid measuring state, the air inlet (101) and the liquid inlet (102) are configured to be in an open state, and the oil discharge port (103) and the heating element (20) are configured to be in a closed state; in the cleaning state, the air inlet (101) and the liquid inlet (102) are configured to be in a closed state, and the oil discharge port (103) and the heating element (20) are configured to be in an open state.

2. The liquid level detector according to claim 1, characterized in that: The heating element (20) is attached to the outer wall of at least a portion of the liquid level detection tube (10) located below the air inlet (101); The heating element (20) is configured as a heating belt, and the heating belt is spirally wound around the liquid level detection tube (10).

3. The liquid level detector according to claim 2, characterized in that: Along the axial direction of the liquid level detection tube (10), the length covered by the heating element (20) accounts for 30% to 70% of the length of the liquid level detection tube (10).

4. The liquid level detector according to any one of claims 1 to 3, characterized in that: A gas opening (104) is formed at one end of the liquid level detection tube (10) facing away from the oil discharge port (103); The liquid level detector further comprises an air blowing assembly (30), the air blowing assembly (30) being connected to the gas port (104), the air blowing assembly (30) comprising a second air inlet pipe (31) and a second air inlet valve (321), the second air inlet valve (321) being mounted on the second air inlet pipe (31); the second air inlet pipe (31) being connected to the gas port (104).

5. The liquid level detector according to claim 4, characterized in that: The inner diameter of the second air inlet pipe (31) is 5% to 10% of the inner diameter of the liquid level detection pipe (10).

6. The liquid level detector according to claim 4, characterized in that: The liquid level detector comprises an exhaust pipeline (40), the exhaust pipeline (40) comprising an exhaust pipe (41) and an exhaust valve (42), the exhaust pipe (41) being connected to the gas port (104), and the exhaust valve (42) being installed on the exhaust pipe (41); the exhaust pipeline (40) and the air blowing assembly (30) are connected in parallel; The exhaust valve (42) is configured to be opened and closed in response to the operating condition of the heating element (20).

7. The liquid level detector according to claim 6, characterized in that: The liquid level detector further comprises an oil drain pipeline (50) connected to the oil drain port (103), the oil drain pipeline (50) comprising an oil drain pipe (51) and an oil drain valve (52), the oil drain pipe (51) being in communication with the oil drain port (103), the oil drain valve (52) being connected to the oil drain pipe (51), and the oil drain valve (52) being configured to adjust opening and closing in response to switching between the liquid measuring state and the cleaning state.

8. The liquid level detector according to claim 7, characterized in that: The liquid level detector further comprises an air intake pipeline (60), wherein the air intake pipeline (60) comprises a first air intake pipe (61) and a first air intake valve (62), wherein the first air intake valve (62) is mounted on the first air intake pipe (61), and the first air intake pipe (61) is in communication with the air intake port (101); The liquid level detector further comprises a liquid inlet pipeline (70); the liquid inlet pipeline (70) comprises a liquid inlet pipe (71) and a liquid inlet valve (72); the liquid inlet valve (72) is mounted on the liquid inlet pipe (71); the liquid inlet pipe (71) is in communication with the liquid inlet port (102); The first air inlet valve (62) and the liquid inlet valve (72) are configured to adjust opening and closing in response to switching between the liquid measuring state and the cleaning state.

9. A low temperature circulation barrel assembly, characterized in that: include: A circulation barrel (200), comprising a first air outlet (2001), a second air outlet (2002) and a liquid outlet (2003) arranged at intervals, wherein the heights of the first air outlet (2001) and the second air outlet (2002) are respectively higher than the liquid outlet (2003), and the height of the second air outlet (2002) is not lower than the height of the first air outlet (2001); In the liquid level detector (100) described in claim 8, the air inlet pipeline (60) is connected between the air inlet (101) and the first air outlet (2001); the liquid inlet pipeline (70) is connected between the liquid inlet (102) and the liquid outlet (2003); and the air blowing assembly (30) is connected between the gas port (104) and the second air outlet (2002).

10. A method for controlling a liquid level detector, characterized in that: The control method of the liquid level detector is based on the low-temperature circulation barrel assembly of claim 9; the control method of the liquid level detector comprises the following steps: Draining the refrigerant in the liquid level detection tube (10); The heating element (20) heats the liquid level detection tube (10); When the refrigeration oil in the liquid level detection tube (10) is in a molten state, the oil discharge port (103) is opened to discharge the refrigeration oil.

11. The control method of the liquid level detector according to claim 10, characterized in that: After the refrigeration oil is discharged, the control method of the liquid level detector further includes: Blowing gas into the liquid level detection tube (10), and the remaining refrigeration oil is discharged from the oil discharge port (103) under the blowing of the gas; Wherein, blowing gas into the liquid level detection tube (10) comprises: blowing gas into the liquid level detection tube (10) at first intervals, with a frequency of not less than n times, n≥3, n∈N; or continuously blowing gas into the liquid level detection tube (10).

12. The control method of the liquid level detector according to claim 11, characterized in that: Before the refrigerant in the liquid level detection tube (10) is emptied, and / or after the remaining refrigeration oil is discharged from the oil discharge port (103) under the blowing of the gas, the control method of the liquid level detector further includes: The first air inlet valve (62) and the liquid inlet valve (72) are opened, the liquid level detection tube (10) is connected to the circulation barrel (200); the oil drain valve (52) and the heating element (20) are closed; After gas-liquid equilibrium is reached in the liquid level detection tube (10), the liquid level height of the circulation barrel (200) is obtained.

13. The control method of the liquid level detector according to claim 10, characterized in that: The refrigerant in the emptying liquid level detection tube (10) comprises: Opening the exhaust pipe (40) causes the pressure in the liquid level detection tube (10) to decrease, and the liquid refrigerant in the liquid level detection tube (10) can be vaporized into gas as the pressure decreases, so as to be discharged from the gas port (104).

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