A device capable of testing the gas-liquid ratio after passing through a throttling device

Abstract

A device that can measure the gas-liquid ratio of the refrigerant in the pipeline after passing through the throttling device when the refrigeration system is in working state. It is divided into a non-test pipeline and a test pipeline. It includes a flow meter, a throttling device, a pipeline, a solenoid valve, a gas-liquid separation device, an open liquid storage container, and a pressure gauge. The test pipeline first uses the gas-liquid separation device to separate the gas phase and liquid phase refrigerant, and the liquid phase is stored in a container with a known bottom area, and its bottom pressure is measured. At this time, the mass flow of the gas phase and the liquid phase can be calculated according to the total flow of the refrigerant and the measured pressure, and finally the ratio is obtained.

Description

Technical Field

[0001] The invention relates to a device capable of measuring the gas-liquid ratio, which is mainly used for detecting the gas-liquid ratio of a refrigerant after passing through a throttling device in the refrigeration industry. Background Art

[0002] Refrigeration products are widely used in life and industry, such as air conditioners, refrigerators, cold storage, etc., which are all refrigeration devices. The four major components of a refrigeration device are compressor, condenser, throttle valve and evaporator. They are connected in sequence by pipes to form a closed system. The refrigerant circulates continuously in the system, changes state, and exchanges heat with the outside world. After the refrigerant passes through the throttle valve, the system pressure decreases, and the refrigerant changes from a single liquid phase flow to a gas-liquid two-phase flow, and then enters the evaporator to work. In the evaporator, the liquid phase absorbs heat through latent heat of vaporization, while the gas phase absorbs heat through sensible heat. Since the latent heat of vaporization of the liquid phase is much different from the heat capacity of the gas phase, when the gas-liquid ratio entering the evaporator is different, the performance of the evaporator measured is quite different. Therefore, if the gas and liquid content in the refrigerant after throttling cannot be accurately obtained, there is a certain deviation in judging the performance of the evaporator only by the heat exchange of the evaporator. However, there is currently no device that can detect the gas-liquid ratio of the refrigerant after the throttle valve. Therefore, developing such a device that can measure the gas-liquid ratio of the refrigerant after the throttle valve under working conditions will be of great benefit to the optimization and performance detection of the evaporator. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a device capable of measuring the gas-liquid ratio after passing through a throttle valve, wherein the device can detect the gas-liquid ratio in the refrigerant after throttling when the refrigeration system is in working condition.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0005] A device for measuring the gas-liquid ratio of a refrigerant after passing through a throttle valve under working conditions includes a flow meter, a throttling device, a pipeline, a switch valve, a gas-liquid separator, a container with a known bottom area, a pressure gauge, and a shell. Since the flow meter for measuring the flow of two-phase flow is not yet mature, it is not advisable to directly measure the flow after the throttling device. Therefore, the flow meter is placed before the throttle valve to measure the total flow of a single liquid phase, and gas-liquid separation is first performed after the throttle valve, and then the gas and liquid phases are measured separately. The working idea of ​​the device is as follows: first, the test pipeline is closed, and the non-test pipeline above starts to run. When the system runs stably, the test pipeline is opened and the timing is started at the same time. The refrigerant will flow into the test pipeline under the action of gravity, and then pass through a gas-liquid separation device to completely separate the gas and liquid phases. The gas phase is discharged into the device, and the liquid phase flows into an open liquid storage container with a known bottom area. The container is equipped with a pressure gauge. After a certain time t, the readings of the pressure gauge before and after the change are read. Since the density of the liquid refrigerant is known, combined with the pressure gauge reading, the height of the liquid refrigerant in the open container can be calculated, and then the volume flow rate and mass flow rate of the liquid refrigerant can be calculated.

[0006] At this time, the total mass flow rate of the refrigerant is the reading of the cumulative flow meter ΔG difference multiplied by time, and then multiplied by the refrigerant density ρ, recorded as m 总 =ΔG×t×ρ.

[0007] The bottom area of ​​the open liquid storage container is recorded as S, and the pressure gauge reading difference is recorded as ΔP 液 , according to the formula ΔP 液 =ρgh, it can be concluded that h = ΔP during this period 液 / ρg,m 液 =S×ΔP 液 / g.

[0008] So the mass flow rate of gas phase refrigerant is: m 气 =m 总 -m 液 , the ratio of gas-liquid phases can be obtained by calculation.

[0009] When used to test the gas-liquid ratio of the fluid after throttling, this device is used as a part of the refrigeration system. Since the container 9 has a certain volume, it can be used as a liquid storage device of the refrigeration system. When the non-test pipeline is working, a certain amount of liquid refrigerant is stored at the bottom of the container. When switching to the test pipeline, the refrigerant stored at the bottom of the container 9 will enter the evaporator through the pipeline to ensure that liquid refrigerant continues to flow into the evaporator. Since the test time is relatively short, the amount of refrigerant at the bottom can meet the refrigerant demand for normal operation of the system during the test. The size of the bottom space is related to the size of the device shell, and can be designed and selected according to different needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a structural schematic diagram of the present invention.

[0011] Figure 2 This is a schematic diagram of the internal fixation of the open liquid storage container of the test pipeline.

[0012] The numbers in the figure are: 1. flow meter; 2. throttling device; 3. pipeline; 4. pipeline; 5. solenoid valve; 6. gas-liquid separation device; 7. open container with known bottom area; 8. pipeline; 9. device housing; 10. pressure gauge. DETAILED DESCRIPTION

[0013] In order to enable researchers in this technical field to better understand the technical solutions in the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0014] like Figure 1 , Figure 2 As shown, the gas-liquid ratio detection device after the throttling device of the present invention is mainly composed of a flow meter 1, a throttling device 2, a pipeline 3, a pipeline 4, a solenoid valve 5, a gas-liquid separation device 6, an open liquid storage container 7, a pipeline 8, a device housing 9, and a pressure gauge 10. The non-test pipeline area includes the pipeline 4, the bottom space of the device and the pipeline 8, and the test pipeline refers to the solenoid valve 5, the gas-liquid separation device 6, the container 7 with a known bottom area and the pressure gauge 10. Before the system is turned on, the solenoid valve 5 of the test pipeline needs to be closed, and at the same time, the non-test pipeline starts to run. The refrigerant flows through the pipeline 3 and the pipeline 4, and is stored in the cavity at the bottom of the device. When the bottom refrigerant reaches the height of the pipeline 8, it enters the evaporator to participate in the normal operation of the system. After the system working condition is stable, open the electromagnetic valve 5 of the test pipeline, open the test pipeline, and the refrigerant flows into the test pipeline, passes through the gas-liquid separation device 6, and the liquid phase flows into the open liquid storage container 7. When the reading of the pressure gauge 10 changes, record its reading for the first time, and record the cumulative flow reading of the flow meter 1 at the same time. After a certain interval of time t, record the pressure gauge reading for the second time, and record the cumulative flow reading of the flow meter 1 at the same time. The difference between the two readings of the flow meter multiplied by the refrigerant density is the total mass of the refrigerant flowing through the test pipeline in time t; the liquid level h flowing into the open liquid storage container in time t is calculated from the difference between the two readings of the pressure gauge, and multiplied by the bottom area S of the open liquid storage container and the refrigerant density ρ, the mass of the liquid phase refrigerant flowing through the test pipeline in time t can be obtained. The gas-liquid phase ratio of the refrigerant after passing through the throttling device can be obtained by calculation.

Claims

1. A device capable of measuring gas-liquid ratio, comprising: Flow meter (1), throttling device (2), pipeline I (3), pipeline II (4), solenoid valve (5), gas-liquid separation device (6), open container (7), pipeline III (8), device housing (9), pressure gauge (10); characterized in that: A flow meter (1) is installed before the throttling device (2) on the pipeline I (3), and the refrigerant is divided into a test pipeline and a non-test pipeline after passing through the throttling device (2); The test pipeline and the non-test pipeline are arranged in parallel, the upper one is the non-test pipeline and the lower one is the test pipeline; the non-test pipeline includes: pipeline II (4), the bottom space of the device, and pipeline III (8); The test pipeline comprises: a solenoid valve (5), a gas-liquid separation device (6), an open container (7), and a pressure gauge (10); The end of the non-test pipeline is connected to the device cavity; when the device is in a non-test state, the refrigerant can flow into the device cavity through the non-test pipeline; The bottom area of ​​the open container (7) is known; the device housing (9) is a stainless steel sealed housing arranged outside; A pressure gauge (10) is installed at the bottom of the open container (7), the upper outlet of which is connected to the device and fixed inside the device; The test pipeline is installed with a solenoid valve (5) for pipeline switching, and the end is connected to a gas-liquid separation device (6), and the gas-liquid separation device is located in an open container (7); The working mode of the device is: The test pipeline is closed and the non-test pipeline is started to operate; when the system is running stably, the test pipeline is opened and timing is started at the same time, and the refrigerant flows into the test pipeline under the action of gravity, and then passes through a gas-liquid separation device (6) to completely separate the gas and liquid phases, and the gas phase is discharged into the device, and the liquid phase flows into an open container (7); after a certain time t, the readings of the pressure gauge (10) are read after the changes; since the density of the liquid refrigerant is known, combined with the reading of the pressure gauge (10), the height of the liquid refrigerant in the open container (7) is calculated, and then the volume flow rate and mass flow rate of the liquid refrigerant are calculated.

2. The device capable of measuring gas-liquid ratio according to claim 1, characterized in that: The flow meter (1) is used to measure the total flow of the refrigerant.

3. The device for measuring gas-liquid ratio according to claim 1, characterized in that: The throttling device (2) can be replaced by yourself.

4. The device for measuring gas-liquid ratio according to claim 1, characterized in that: The overall sealing performance of the device shell (9) is good, and its volume can be changed according to the required amount of refrigerant to be tested.

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