A measuring device

Abstract

The present invention discloses a measuring device, comprising: a plurality of connected measuring units, wherein the plurality of measuring units are respectively used to measure a plurality of different types of parameters of a refrigerant-lubricant saturated solution, and at least two of the plurality of different types of parameters of the refrigerant-lubricant saturated solution include the viscosity of the refrigerant-lubricant saturated solution, the surface tension of the refrigerant-lubricant saturated solution, and the solubility of the refrigerant-lubricant saturated solution. This application reduces the number of measuring devices, simplifies the measuring steps, reduces the labor cost, and reduces the workload of the staff.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration, and particularly to a measuring device. Background Art

[0002] In a compression refrigeration system, lubricating oil exists in the compressor, which can reduce the friction of mechanical components and carry away the heat inside the compressor. It is a key part to ensure the stable operation and efficient work of the compressor. And the lubricating oil having suitable thermophysical properties is the basic guarantee for normal lubrication work and is also a key factor affecting the performance of the refrigeration system.

[0003] As a circulating working medium in the refrigeration system, the refrigerant is also an essential core part. However, it is not comprehensive to consider only the change in the thermophysical properties of the lubricating oil or the refrigerant on the refrigeration system. This is because in a compression refrigeration system, the refrigerant is in direct contact with the lubricating oil, and part of the gaseous refrigerant will be partially dissolved in the lubricating oil and enter components such as the compressor, condenser, and evaporator together. The dissolution of the refrigerant in the lubricating oil will change the properties such as the viscosity, density, and surface tension of the lubricating oil, and the thermophysical properties of the changed refrigerant-lubricant refrigerant-lubricant saturated solution are the parameters that actually affect the operation of the compressor. For the measurement of multiple thermophysical properties of the refrigerant-lubricant refrigerant-lubricant saturated solution, the existing technology measures multiple thermophysical properties of the refrigerant-lubricant saturated solution separately, using a large number of devices, with cumbersome measurement steps and complex calculation programs, resulting in a large workload for operators. Summary of the Invention

[0004] Based on this, it is necessary to provide a measuring device with simplified operation steps and high convenience.

[0005] A measuring device includes: a plurality of connected measuring units, each of the plurality of measuring units is used to measure a plurality of different types of parameters of the refrigerant-lubricant saturated solution, and at least two of the plurality of different types of the parameters of the refrigerant-lubricant saturated solution include the viscosity of the refrigerant-lubricant saturated solution, the surface tension of the refrigerant-lubricant saturated solution, and the solubility of the refrigerant-lubricant saturated solution.

[0006] In one embodiment, the measuring device includes a receiving unit, a first measuring unit, a second measuring unit, and a third measuring unit respectively connected to the receiving unit;

[0007] The receiving unit is used to receive the refrigerant-lubricant saturated solution;

[0008] The first measuring unit is used to measure the viscosity of the refrigerant-lubricant saturated solution output by the receiving unit;

[0009] The second measurement unit is configured to measure the surface tension of the refrigerant-lubricant saturated solution output by the containment unit;

[0010] The third measurement unit is configured to measure the solubility of the refrigerant-lubricant saturated solution output by the containment unit.

[0011] In one embodiment, the containment unit includes a first containment kettle and a second containment kettle. The first measurement unit, the second measurement unit, and the third measurement unit are all connected to the first containment kettle. The first containment kettle is connected to the second containment kettle. The first containment kettle is configured to contain lubricating oil, the second containment kettle is configured to contain refrigerant, and the first containment kettle is further configured to contain the refrigerant-lubricant saturated solution obtained after mixing the refrigerant output by the second containment kettle and the lubricating oil.

[0012] In one embodiment, the first measurement unit includes a first measurement subunit and a second measurement subunit. The first measurement subunit and the second measurement subunit are both connected to the containment unit. The first measurement subunit is configured to measure the viscosity of the refrigerant-lubricant saturated solution with low viscosity, and the second measurement subunit is configured to measure the viscosity of the refrigerant-lubricant saturated solution with high viscosity.

[0013] In one embodiment, the first measurement subunit has a conducting state and a disconnected state. When the first measurement subunit is in the conducting state, the containment unit, the first measurement subunit, and the second measurement subunit are sequentially connected to form a first path, so that the first measurement subunit measures the viscosity of the refrigerant-lubricant saturated solution with low viscosity flowing through the first path. When the first measurement subunit is in the disconnected state, the containment unit and the second measurement subunit are sequentially connected to form a second path, so that the second measurement subunit measures the viscosity of the refrigerant-lubricant saturated solution with high viscosity flowing through the second path.

[0014] In one embodiment, the first measurement unit further includes a control unit. The control unit is connected to the first measurement subunit, and the control unit is configured to control the first measurement subunit to switch between the conducting state and the disconnected state.

[0015] In one embodiment, the first measurement subunit includes a first capillary tube and a first differential pressure sensor. The first capillary tube has a first inlet end and a first outlet end. The first inlet end of the first capillary tube is connected to the receiving unit. The refrigerant-lubricant saturated solution with a preset flow rate output by the receiving unit can flow into the first capillary tube through the first inlet end of the first capillary tube and flow out of the first capillary tube through the first outlet end of the first capillary tube. The ratio of the length to the inner diameter of the first capillary tube is not less than a preset value. One end of the first differential pressure sensor is connected to the first inlet end, and the other end of the first differential pressure sensor is connected to the first outlet end. The first differential pressure sensor is used to measure the pressure difference between the first inlet end and the first outlet end.

[0016] In one embodiment, the second measurement unit includes a third capillary tube, a fourth capillary tube, a scale, a density sensor, and a first pressure sensor. The third capillary tube, the fourth capillary tube, and the scale are arranged vertically side by side in the receiving unit. The inner diameters of the third capillary tube and the fourth capillary tube are different. The refrigerant-lubricant saturated solution output by the receiving unit can enter the third capillary tube through the inlet end of the third capillary tube and flow along the inner side wall of the third capillary tube. The refrigerant-lubricant saturated solution can also enter the fourth capillary tube through the inlet end of the fourth capillary tube and flow along the inner side wall of the fourth capillary tube. The scale is used to indicate the liquid level height of the refrigerant-lubricant saturated solution in the third capillary tube and the fourth capillary tube. The density sensor is connected to the receiving unit and is used to measure the density of the refrigerant-lubricant saturated solution in the receiving unit. The first pressure sensor is connected to the receiving unit and is used to measure the pressure of the refrigerant-lubricant saturated solution in the receiving unit.

[0017] In one embodiment, the third measurement unit includes a collection tank and a weighing device. The collection tank is connected to the receiving unit and is used to receive the refrigerant-lubricant saturated solution output by the receiving unit. The weighing device is used to measure the mass of the collection tank.

[0018] In one embodiment, the measuring device further includes a system cavity. The receiving unit, the first measurement unit, the second measurement unit, and the third measurement unit are all arranged in the system cavity.

[0019] The measurement of at least two of the viscosity of the refrigerant-lubricant saturated solution, the surface tension of the refrigerant-lubricant saturated solution, and the solubility of the refrigerant-lubricant saturated solution can be achieved by a measurement device. This application reduces the number of measurement devices, simplifies the measurement steps, reduces the labor cost, and decreases the workload of the staff. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0021] Figure 1 It is a schematic structural diagram of the measurement device in an embodiment;

[0022] Figure 2 It is a schematic partial structural diagram of the measurement device in an embodiment;

[0023] Figure 3 It is a schematic partial structural diagram of the second measurement unit of the measurement device in an embodiment;

[0024] Figure 4 It is a schematic partial structural diagram of the third measurement unit of the measurement device in an embodiment;

[0025] Names and serial numbers of components in the figure: 01, measuring unit; 1, receiving unit; 11, first receiving kettle; 12, second receiving kettle; 13, visual window; 14, first valve; 15, second valve; 16, third valve; 2, first measuring unit; 21, first measuring subunit; 211, first capillary tube; 212, second differential pressure sensor; 213, first support column; 22, second measuring subunit; 221, second capillary tube; 222, second differential pressure sensor; 223, eleventh valve; 224, second support column; 23, magnetic pump; 24, filter; 25, collection bottle; 26, fourth valve; 27, fifth valve; 28, sixth valve; 29, seventh valve; 210, tenth valve; 3, second measuring unit; 31, limit frame; 32, third capillary tube; 33, fourth capillary tube; 34, scale; 35, limiting part; 36, photographic equipment; 37, adjusting bracket; 38, density sensor; 381, probe; 39, first pressure sensor; 4, third measuring unit; 41, collection tank; 410, collection tank body; 411, first magnetic rotor; 42, twelfth valve; 43, thirteenth valve; 6, vacuum pump; 7, stirring unit; 71, magnetic stirrer; 72, second magnetic rotor; 8, fourth measuring unit; 81, second pressure sensor; 82, thermometer; 83, standard resistor; 84, DC power supply; 85, multimeter; 86, display; 9, system cavity; 10, temperature control unit; 101, first temperature controller; 1011, first constant temperature cavity; 1012, first heat exchange tube; 102, second temperature controller; 1021, second constant temperature cavity; 1022, second heat exchange tube; 11, control unit; 111, auxiliary path; 112, valve; 1121, eighth valve; 1122, ninth valve.

[0026] The realization, functional features and advantages of the object of the present invention will be further described in conjunction with the embodiments and with reference to the accompanying drawings. Specific embodiments

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0028] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0029] In addition, the descriptions involving "first", "second", etc. in the present invention are for descriptive purposes only, and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, "and / or" throughout the text includes three scenarios. Taking A and / or B as an example, it includes the technical solution of A, the technical solution of B, and the technical solution where both A and B are satisfied simultaneously. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0030] Reference Figure 1 , the present application provides a measuring device, which includes a plurality of connected measuring units 01. The plurality of measuring units 01 are respectively used to measure a plurality of different types of parameters of the refrigerant-lubricant saturated solution. The plurality of different types of parameters of the refrigerant-lubricant saturated solution include at least two of the viscosity of the refrigerant-lubricant saturated solution, the surface tension of the refrigerant-lubricant saturated solution, and the solubility of the refrigerant-lubricant saturated solution.

[0031] By using a measuring device, the measurement of at least two of the viscosity of the refrigerant-lubricant saturated solution, the surface tension of the refrigerant-lubricant saturated solution, and the solubility of the refrigerant-lubricant saturated solution can be achieved. The present application reduces the number of measuring devices, simplifies the measurement steps, reduces the labor cost, and decreases the workload of the staff.

[0032] Reference Figure 1 , the measuring device includes a housing unit 1 and a first measuring unit 2, a second measuring unit 3, and a third measuring unit 4 respectively connected to the housing unit 1. The housing unit 1 is used to house the refrigerant-lubricant saturated solution. The first measuring unit 2 is used to measure the viscosity of the refrigerant-lubricant saturated solution output by the housing unit 1. The second measuring unit 3 is used to measure the surface tension of the refrigerant-lubricant saturated solution output by the housing unit 1. The third measuring unit 4 is used to measure the solubility of the refrigerant-lubricant saturated solution output by the housing unit 1.

[0033] Reference Figure 1, the containment unit 1 includes a first containment kettle 11 and a second containment kettle 12. The first measurement unit 2, the second measurement unit 3, and the third measurement unit 4 are all connected to the first containment kettle 11. The first containment kettle 11 is connected to the second containment kettle 12. The first containment kettle 11 is used to contain lubricating oil, and the second containment kettle 12 is used to contain refrigerant. The first containment kettle 11 is also used to contain the refrigerant-lubricant saturated solution obtained after the refrigerant and lubricating oil output from the second containment kettle 12 are mixed.

[0034] Specifically, the refrigerant can be Freon, hydrocarbon, ammonia, air, hydrogen, etc. In this embodiment, the refrigerant is in a gaseous state.

[0035] Specifically, the measuring device further includes a vacuum pump 6. The vacuum pump 6 is connected to the first containment kettle 11 and is used to perform vacuum treatment on the first containment kettle 11. The vacuum pump 6 is also connected to the second containment kettle 12 and is used to perform vacuum treatment on the second containment kettle 12.

[0036] Specifically, the containment unit 1 further includes a first valve 14. The first valve 14 is arranged on the common path of the connection path between the first containment kettle 11 and the second containment kettle 12 and the connection path between the second containment kettle 12 and the vacuum pump 6. The first valve 14 is used to control the on-off of the connection path between the first containment kettle 11 and the second containment kettle 12 and the on-off of the connection path between the second containment kettle 12 and the vacuum pump 6.

[0037] Specifically, the containment unit 1 further includes a second valve 15. The second valve 15 is arranged on the common path of the connection path between the vacuum pump 6 and the second containment kettle 12 and the connection path between the vacuum pump 6 and the first containment kettle 11. The second valve 15 is used to control the on-off of the connection path between the vacuum pump 6 and the second containment kettle 12 and the on-off of the connection path between the vacuum pump 6 and the first containment kettle 11.

[0038] Specifically, the containment unit 1 further includes a third valve 16. The third valve 16 is arranged on the common path of the connection path between the first containment kettle 11 and the vacuum pump 6 and the connection path between the first containment kettle 11 and the second containment kettle 12. The third valve 16 is used to control the on-off of the connection path between the first containment kettle 11 and the vacuum pump 6 and the on-off of the connection path between the first containment kettle 11 and the second containment kettle 12.

[0039] Reference Figure 1 and Figure 2, the first measurement unit 2 includes a first measurement subunit 21 and a second measurement subunit 22. Both the first measurement subunit 21 and the second measurement subunit 22 are connected to the containment unit 1. The first measurement subunit 21 is used to measure the viscosity of a refrigerant-lubricant saturated solution with low viscosity, and the second measurement subunit 22 is used to measure the viscosity of a refrigerant-lubricant saturated solution with high viscosity. Specifically, both the first measurement subunit 21 and the second measurement subunit 22 are connected to the first containment kettle 11.

[0040] The standard for defining the high and low viscosity of the refrigerant-lubricant saturated solution is 20 mps, that is, a refrigerant-lubricant saturated solution with a viscosity higher than 20 mps is a high-viscosity refrigerant-lubricant saturated solution, and a refrigerant-lubricant saturated solution with a viscosity lower than 20 mps is a low-viscosity refrigerant-lubricant saturated solution.

[0041] Reference Figure 1 , the first measurement subunit 21 has a conducting state and a disconnected state. When the first measurement subunit 21 is in the conducting state, the containment unit 1, the first measurement subunit 21, and the second measurement subunit 22 are connected in sequence to form a first path, so that the first measurement subunit 21 measures the viscosity of the low-viscosity refrigerant-lubricant saturated solution flowing through the first path. When the first measurement subunit 21 is in the disconnected state, the containment unit 1 and the second measurement subunit 22 are connected in sequence to form a second path, so that the second measurement subunit 22 measures the viscosity of the high-viscosity refrigerant-lubricant saturated solution flowing through the second path.

[0042] Reference Figure 1 and Figure 2 , the first measurement unit 2 further includes a control unit 11. The control unit 11 is connected to the first measurement subunit 21, and the control unit 11 is used to control the first measurement subunit 21 to switch between the conducting state and the disconnected state.

[0043] Specifically, the control unit includes an auxiliary path 111 and a valve 112. The auxiliary path 111 is connected in parallel at both ends of the first measurement subunit 21, and the valve 112 is arranged on the auxiliary path 111. The valve 112 is used to control the on-off of the auxiliary path 111. In this embodiment, the number of valves is two, specifically the eighth valve 1121 and the ninth valve 1222. Both the eighth valve 1121 and the ninth valve 1122 are used to control the on-off of the auxiliary path 111.

[0044] Specifically, the first measurement unit 2 further includes a magnetic pump 23. The magnetic pump 23 is arranged on the common path of the first path and the second path. The magnetic pump 23 is used to provide power for transporting the refrigerant-lubricant saturated solution output from the first containment kettle 11 to the first measurement subunit 21 or the second measurement subunit 22, so that the refrigerant-lubricant saturated solution enters the first measurement subunit 21 or the second measurement subunit 22 at a stable flow rate.

[0045] Specifically, the first measurement unit 2 further includes a filter 24. The filter 24 is disposed between the magnetic pump 23 and the first measurement subunit 21. The filter 24 is used to filter the refrigerant-lubricant saturated solution output from the first containment kettle 11 to remove impurities in the refrigerant-lubricant saturated solution, so as to avoid the influence of impurities on the measurement of the viscosity of the refrigerant-lubricant saturated solution.

[0046] Specifically, the first measurement unit 2 further includes a fourth valve 26. The fourth valve 26 is disposed between the first containment kettle 11 and the magnetic pump 23. The fourth valve 26 is used to control the on-off of the connection path between the first containment kettle 11 and the magnetic pump 23.

[0047] Specifically, the first measurement unit 2 further includes a fifth valve 27. The fifth valve 27 is disposed between the magnetic pump 23 and the filter 24. The fifth valve 27 is used to control the on-off of the connection path between the magnetic pump 23 and the filter 24.

[0048] Specifically, the first measurement unit 2 further includes a sixth valve 28. The sixth valve 28 is disposed between the filter 24 and the first measurement subunit 21. The sixth valve 28 is used to control the on-off of the connection path between the filter 24 and the first measurement subunit 21.

[0049] Specifically, the first measurement unit 2 further includes a seventh valve 29. The seventh valve 29 is disposed between the first measurement subunit 21 and the second measurement subunit 22. The seventh valve 29 is used to control the on-off of the connection path between the first measurement subunit 21 and the second measurement subunit 22.

[0050] Specifically, the first measurement unit 2 further includes a collection bottle 25. The collection bottle 25 is connected to the second measurement subunit 22. The collection bottle 25 is used to collect the refrigerant-lubricant saturated solution output by the second measurement subunit 22.

[0051] Specifically, the first measurement unit 2 further includes a tenth valve 210. The tenth valve 210 is disposed between the second measurement subunit 22 and the collection bottle 25. The tenth valve 210 is used to control the on-off of the connection path between the second measurement subunit 22 and the collection bottle 25. Further, the tenth valve 210 is a back pressure valve, and the tenth valve 210 is also used to adjust the outlet back pressure P2 in the connection path between the second measurement subunit 22 and the collection bottle 25 by adjusting the opening degree of the tenth valve 210.

[0052] Specifically, the other end of the second measurement subunit 22 is connected to the first containment kettle 11. The refrigerant-lubricant saturated solution output by the second measurement subunit can flow back into the first containment kettle 11, thereby reducing the workload of repeatedly filling the refrigerant-lubricant saturated solution and improving the operation stability of the equipment.

[0053] Specifically, the first measurement unit 2 further includes an eleventh valve 223. The eleventh valve 223 is disposed between the second measurement subunit 22 and the first receiving kettle 11, and is used to control the on-off of the connection path between the other end of the second measurement subunit 22 and the first receiving kettle 11.

[0054] Reference Figure 2 , the first measurement subunit 21 includes a first capillary 211 and a first differential pressure sensor 212. The first capillary 211 has a first inlet end and a first outlet end. The first inlet end of the first capillary 211 is connected to the receiving unit 1, and the refrigerant-lubricant saturated solution with a preset flow rate output by the receiving unit 1 can flow into the first capillary 211 through the first inlet end of the first capillary 211 and flow out of the first capillary 211 through the first outlet end of the first capillary 211; the ratio of the length to the inner diameter of the first capillary 211 is not less than a preset value. One end of the first differential pressure sensor 212 is connected to the first inlet end, and the other end of the first differential pressure sensor 212 is connected to the first outlet end. The first differential pressure sensor 212 is used to measure the pressure difference between the first inlet end and the first outlet end.

[0055] Specifically, the first inlet end of the first capillary 211 is connected to the first receiving kettle 11.

[0056] Specifically, the second measurement subunit includes a second capillary 221 and a second differential pressure sensor 222. The second capillary 221 has a second inlet end and a second outlet end. The second inlet end of the second capillary 221 is connected to the first receiving kettle 11, and the refrigerant-lubricant saturated solution with a preset flow rate output by the first receiving kettle 11 can flow into the second capillary 221 through the second inlet end of the second capillary 221 and flow out of the second capillary 221 through the second outlet end of the second capillary 221; the ratio of the length to the inner diameter of the second capillary 221 is not less than a preset value. One end of the second differential pressure sensor 222 is connected to the second inlet end, and the other end of the second differential pressure sensor 222 is connected to the second outlet end. The second differential pressure sensor 222 is used to measure the pressure difference between the second inlet end and the second outlet end.

[0057] Specifically, the inner side wall of the first capillary 211 is smooth, and the inner side wall of the second capillary 221 is smooth. With such a setting, it is possible to avoid the pressure difference caused by friction from being included in the pressure difference caused by the viscosity of the refrigerant-lubricant saturated solution, artificially increasing the error.

[0058] Specifically, when the refrigerant-lubricant saturated solution flows in the first capillary 211, due to its own viscosity effect, a frictional force will be generated between the refrigerant-lubricant saturated solution and the inner side wall of the first capillary 211. The energy loss generated by the flowing refrigerant-lubricant saturated solution overcoming this frictional force is called the head loss, that is, the pressure difference.

[0059] Specifically, the inner diameter r1 of the first capillary 211 is 0.25 mm, the length L1 is 1 m, and the structural coefficient of the first capillary 211 is Z1.

[0060] The first measurement subunit 21 further includes a first support column 213. The first capillary 211 is wound around the first support column 213. The first support column 213 is used to better fix the first capillary 211, and the heights of the first inlet end and the first outlet end are flush.

[0061] The inner diameter r2 of the second capillary 221 is 1 mm, the length L2 is 7 m, and the structural coefficient of the first capillary 211 is Z2.

[0062] The second measurement subunit 22 further includes a first support column 224. The second capillary 221 is wound around the first support column 224. The first support column 224 is used to better fix the second capillary 221, and the heights of the second inlet end and the second outlet end are flush.

[0063] Specifically, the preset flow rate is Q, and the viscosity measurement formula of the refrigerant-lubricant saturated solution is When measuring a low-viscosity refrigerant-lubricant saturated solution, ▽P is the pressure difference between the first inlet end and the first outlet end measured by the first differential pressure sensor 212, and Z is the structural coefficient Z1 of the first capillary 211; when measuring a high-viscosity refrigerant-lubricant saturated solution, ▽P is the pressure difference between the second inlet end and the second outlet end measured by the second differential pressure sensor 222, and Z is the structural coefficient Z2 of the second capillary.

[0064] Reference Figures 1 to 3 , the second measurement unit 3 includes a third capillary 32, a fourth capillary 33, a scale 34, a density sensor 38, and a first pressure sensor 39. The third capillary 32, the fourth capillary 33, and the scale 34 are vertically arranged side by side in the receiving unit 1. The inner diameters of the third capillary 32 and the fourth capillary 33 are different. The refrigerant-lubricant saturated solution output from the receiving unit 1 can enter the third capillary 32 through the inlet end of the third capillary 32 and flow along the inner side wall of the third capillary 32. The refrigerant-lubricant saturated solution can also enter the fourth capillary 33 through the inlet end of the fourth capillary 33 and flow along the inner side wall of the fourth capillary 33. The scale 34 is used to indicate the liquid level height of the refrigerant-lubricant saturated solution in the third capillary 32 and the fourth capillary 33. The density sensor 38 is connected to the receiving unit 1, and the density sensor 38 is used to measure the density of the refrigerant-lubricant saturated solution in the receiving unit 1. The first pressure sensor 39 is connected to the receiving unit 1, and the first pressure sensor 39 is used to measure the pressure of the refrigerant-lubricant saturated solution in the receiving unit 1.

[0065] Specifically, under the combined action of the capillary action of the third capillary 32 and the fourth capillary 33 and the surface tension of the refrigerant-lubricant saturated solution, the refrigerant-lubricant saturated solution can climb along the inner walls of the third capillary 32 and the fourth capillary 33, so as to form two liquid levels in the third capillary 32 and the fourth capillary 33, and both liquid levels are higher than the liquid level of the refrigerant-lubricant saturated solution in the first receiving kettle 11.

[0066] Specifically, the inner diameter r3 of the third capillary 32 needs to satisfy 0.04 mm ≤ r3 ≤ 0.08 mm, and the inner diameter calibration needs to be carried out before use. The inner diameter r4 of the fourth capillary 33 needs to satisfy 0.2 mm ≤ r4 ≤ 0.25 mm, and the inner diameter calibration needs to be carried out before use.

[0067] Specifically, the scale 34 is arranged between the third capillary 32 and the fourth capillary 33, which is convenient for observing the liquid levels of the refrigerant-lubricant saturated solution in the third capillary 32 and the fourth capillary 33.

[0068] Specifically, the density sensor 38 further includes a probe 381. One end of the density sensor 38 where the probe 38 is arranged extends into the interior of the first receiving kettle 11, and the probe 381 is used to collect the density signal of the refrigerant-lubricant saturated solution in the first receiving kettle 11. The density sensor 38 is preferably an ultrasonic sensor, which has high measurement accuracy and good measurement stability.

[0069] Specifically, the second measurement unit further includes a washer. The washer is arranged between the first receiving kettle 11 and the density sensor 38, and the washer is used to seal the connection between the first receiving kettle 11 and the density sensor 38. The material of the washer is polytetrafluoroethylene. The polytetrafluoroethylene washer is corrosion-resistant, has stable physical properties, is resistant to high and low temperatures, and has good sealing performance. The density of the refrigerant-lubricant saturated solution is represented by ρ.

[0070] Specifically, the second measurement unit 3 further includes a limiting frame 31. The third capillary 32, the fourth capillary 33 and the scale 34 are all vertically arranged on the limiting frame 31, and the limiting frame 31 is arranged inside the first receiving kettle 11. Further, a plurality of through holes are opened at the bottom end of the limiting frame 31, and the plurality of through holes are respectively used for inserting the third capillary 32, the fourth capillary 33 and the scale 34, so as to fix the third capillary 32, the fourth capillary 33 and the scale 34 on the limiting frame 31, and the refrigerant-lubricant saturated solution in the first receiving kettle 11 can enter the third capillary 32 and the fourth capillary 33 through the through holes.

[0071] Specifically, the second measurement unit 3 further includes a limiting portion 35. The limiting portion 35 is specifically arranged at both ends of the top of the limiting frame 31. The limiting portion 35 is used to limit the limiting frame 31 in the first receiving kettle 11 to reduce the error caused by the angle problem of the limiting frame 31 during the process of measuring the surface tension of the refrigerant-lubricant saturated solution. In this embodiment, the limiting portion 35 is a protrusion extending from both ends of the top of the limiting frame 31.

[0072] Specifically, a visual window 13 is further arranged on the first receiving kettle 11, which is convenient to observe the liquid level height inside the first receiving kettle 11 through the visual window 13, as well as the color change and the presence or absence of stratification phenomenon of the gas-liquid mixture when in gas-liquid phase equilibrium.

[0073] Specifically, the second measurement unit 3 further includes a photographing device 36. The photographing device 36 is arranged outside the first receiving kettle 11 and is directly opposite to the visual window 13. The photographing device 36 is used to take pictures of the third capillary 32, the fourth capillary 33 and the scale 34 to obtain a picture of the height difference of the liquid levels of the refrigerant-lubricant saturated solution between the third capillary 32 and the fourth capillary 33 indicated by the scale 34.

[0074] Further, the picture includes a plurality of unit pixels. The scale 34 is used to indicate the length a represented by a unit pixel. There are n unit pixels between the liquid levels of the third capillary 32 and the fourth capillary 33. Therefore, the liquid level height difference Δh between the third capillary 32 and the fourth capillary 33 is Δh = n·a. With such a setting, the accuracy of the liquid level height difference between the third capillary 32 and the fourth capillary 33 can be improved, and the measurement accuracy of the surface tension can be further improved.

[0075] Further, the photographing device 36 is a high-pixel camera, which further improves the measurement accuracy of the surface tension.

[0076] Specifically, the second measurement unit 3 further includes an adjusting bracket 37. The photographing device 36 is arranged on the adjusting bracket 37, which is convenient for the photographing device 36 to realize the adjustment of the horizontal and vertical positions relative to the first receiving kettle 11.

[0077] Specifically, the calculation formula for the surface tension σ of the refrigerant-lubricant saturated solution is where ρ g is the density of the refrigerant-lubricant saturated solution in the first receiving kettle 116 measured by the density sensor 38, g is the acceleration due to gravity, and ρ is the pressure value P1 measured by the first pressure sensor 91.

[0078] Reference Figure 1 and Figure 2, the third measuring unit 4 includes a collection tank 41 and a weighing device. The collection tank 41 is connected to the containment unit 1. The collection tank 41 is used to contain the refrigerant-lubricant saturated solution output by the containment unit 1, and the weighing device is used to measure the mass of the collection tank 41.

[0079] Specifically, the weighing device can be a platform scale, an electronic scale, a steelyard, a tray balance, a physical balance, etc.

[0080] Specifically, the third measuring device further includes a twelfth valve 42 and a thirteenth valve 43. Both the twelfth valve 42 and the thirteenth valve 43 are arranged between the first containment kettle 11 and the collection tank 41, and both the twelfth valve 42 and the thirteenth valve 43 are used to control the on-off of the connection path between the first containment kettle 11 and the collection tank 41.

[0081] Specifically, the collection tank 41 includes a collection tank body 410 and a first magnetic rotor 411. The weighing device measures the total mass of the collection tank body 410 and the first magnetic rotor 411. The first magnetic rotor 411 is used to stir the refrigerant-lubricant saturated solution in the collection tank 41 to accelerate the escape of the refrigerant in the refrigerant-lubricant saturated solution in the collection tank 41.

[0082] Specifically, the weighing device is used to measure the mass of the empty collection tank 41 (denoted as m3), the weighing device is also used to measure the mass of the collection tank 41 containing the refrigerant-lubricant saturated solution (denoted as m1), and the weighing device is also used to measure the mass of the collection tank 41 containing the refrigerant-lubricant saturated solution after the refrigerant has escaped (denoted as m2). The calculation formula for the mass solubility w of the refrigerant-lubricant saturated solution is:

[0083] Reference Figure 1 , the measuring device further includes a system cavity 9. The containment unit 1, the first measuring unit 2, the second measuring unit 3, and the third measuring unit 4 are all arranged in the system cavity 9.

[0084] Reference Figure 1 , the system cavity 9 is used to contain a heat exchange medium. The heat exchange medium can contact the containment unit 1, and the heat exchange medium is used to perform heat exchange with the refrigerant-lubricant saturated solution in the containment unit 1 to obtain refrigerant-lubricant saturated solutions at different temperatures.

[0085] Specifically, the material of the system cavity 9 is stainless steel, which is corrosion-resistant. The heat exchange medium is preferably water, which has good heat exchange effect and low cost.

[0086] Specifically, the measuring device further includes a stirring unit 7. The stirring unit 7 is connected to the first receiving kettle 11. The stirring unit 7 is used to stir and mix the lubricating oil and the refrigerant in the first receiving kettle 11 to accelerate the formation of the refrigerant-lubricant saturated solution.

[0087] Specifically, the stirring unit 7 includes a magnetic stirrer 71 and a second magnetic rotor 72. The magnetic stirrer 71 is arranged outside the system cavity 9, and the second magnetic rotor 72 is arranged inside the first receiving kettle 11. The output shaft of the magnetic stirrer 71 is connected to the second magnetic rotor 72 to drive the second magnetic rotor 72 to rotate, so as to stir and mix the lubricating oil and the refrigerant in the first receiving kettle 11 and accelerate the formation of the refrigerant-lubricant saturated solution in the first receiving kettle 11.

[0088] Reference Figure 1 and Figure 2 The measuring device further includes a fourth measuring unit 8. The fourth measuring unit 8 is connected to the system cavity 9. The fourth measuring unit 8 is used to measure the temperature and pressure inside the system cavity 9.

[0089] Specifically, the fourth measuring unit 8 further includes a second pressure sensor 81. One end of the second pressure sensor 81 is connected to the connection path between the second measuring subunit 22 and the collection bottle 25. The second pressure sensor 81 is used to measure the outlet back pressure P2 of the connection path between the second measuring subunit 22 and the collection bottle 25.

[0090] Specifically, the fourth measuring unit 8 further includes a thermometer 82. One end of the thermometer 82 extends into the system cavity 9. The thermometer 82 is used to measure the temperature inside the system cavity 9.

[0091] Specifically, the thermometer 82 is a platinum resistance thermometer 82, which has a wide temperature measurement range and high measurement accuracy.

[0092] Specifically, the fourth measuring unit 8 further includes a display 86. The display 86 is connected to the other end of the first pressure sensor 39. The display 86 is used to display the pressure P1 inside the first receiving kettle 11 measured by the first pressure sensor 39; the display 86 is also connected to the other end of the second pressure sensor 81, and the display 86 is also used to display the outlet back pressure P2 of the connection path between the second measuring subunit 22 and the collection bottle 25 measured by the second pressure sensor 81; the display 86 is also connected to the other end of the thermometer 82, and the display 86 is also used to display the temperature inside the system cavity 9 measured by the thermometer 82.

[0093] Specifically, the other end of the density sensor 38 is connected to the display 86. The display is also used to display the density of the refrigerant-lubricant saturated solution in the first receiving kettle 11 measured by the density sensor 38.

[0094] Specifically, the fourth measurement unit 8 further includes a DC power supply 84. The DC power supply 84 is arranged in the common path of the connection path between the first pressure sensor 39 and the display 86 and the connection path between the second pressure sensor 81 and the display 86. The DC power supply 84 is used to output a DC current to the display 86. Further, the DC power supply 84 is a DC constant current power supply, and the DC constant current power supply is used to output a stable constant current DC current to the display 86.

[0095] Specifically, the fourth measurement unit 8 further includes a standard resistor 83. The standard resistor 83 is arranged between the display 86 and the DC power supply 84. The standard resistor 83 ensures that the current flowing through the display 86 does not exceed the rated value or the specified value required for actual operation, so as to ensure the normal operation of the display 86.

[0096] Specifically, the fourth measurement unit 8 further includes a multimeter 85. The multimeter 85 is arranged between the display 86 and the DC power supply 84, and the other end of the thermometer is connected to the display 86 through the multimeter 85. The multimeter 85 is used to collect the pressure signals and temperature signals output by the first pressure sensor 8, the second pressure sensor 81 and the thermometer 82.

[0097] Reference Figure 1 , the measuring device further includes a temperature control unit 10. The temperature control unit 10 is connected to the system cavity 9. The temperature control unit 10 is used to control the temperature in the system cavity 9, so as to measure different types of parameters of the refrigerant-lubricant saturated solution at different temperatures.

[0098] Specifically, the temperature control unit 10 includes a first temperature controller 101 and a second temperature controller 102. The first temperature controller 101 includes a first constant temperature cavity 1011 and a first heat exchange tube 1012. The first constant temperature cavity 1011 is arranged outside the system cavity 9. The first constant temperature cavity 1011 is used to generate cold. One end of the first heat exchange tube 1012 is connected to the first constant temperature cavity 1011, and the other end of the first heat exchange tube 1012 is connected to the system cavity 9. The first heat exchange tube 1012 is used to transfer the cold generated by the first constant temperature cavity 1011 to the system cavity 9.

[0099] The second temperature controller 102 includes a second constant temperature chamber 1021 and a second heat exchange pipe 1022. The second constant temperature chamber 1021 is arranged outside the system chamber 9. The second constant temperature chamber 1021 is used to generate heat. One end of the second heat exchange pipe 1022 is connected to the second constant temperature chamber 1021, and the other end of the second heat exchange pipe 1022 is connected to the system chamber 9. The second heat exchange pipe 1022 is used to transfer the heat generated by the second constant temperature chamber 1021 to the system chamber 9. The reason for setting two temperature controllers is that: when the refrigerant-lubricant saturated solution reaches phase equilibrium, the temperature is 0-75°C. The first temperature controller 101 provides cold, and the second temperature controller 102 provides heat. The first temperature controller 101 and the second temperature controller 102 cooperate to meet the temperature requirement of 0-75°C.

[0100] The measurement of the viscosity, surface tension and solubility of the refrigerant-lubricant saturated solution by using the present invention includes the following steps:

[0101] S1. Before the experiment starts, clean the first measurement unit 2, fill 200 ml of ethanol into the first receiving kettle 11, turn on the temperature control unit 10 to keep the temperature of the system chamber 9 at 60°C, then turn on the magnetic pump 23, and sequentially open the fourth valve 26, the fifth valve 27, the sixth valve 28, the seventh valve 29, the eighth valve 1121, the ninth valve 1122 and the tenth valve 210, so that the ethanol slowly flows in the pipeline connected with the fourth valve 26, the fifth valve 27, the sixth valve 28, the seventh valve 29, the eighth valve 1121, the ninth valve 1122 and the tenth valve 210. After thoroughly cleaning twice, blow nitrogen into the pipeline to remove the residual samples in the pipeline, and then close all the valves.

[0102] S2. Connect the second receiving kettle 12 with the refrigerant tank through a stainless steel pipeline, close the third valve 16, turn on the vacuum pump 6, slowly open the first valve 14 and the second valve 15 to evacuate the stainless steel pipeline and the second receiving kettle 12. When the pressure display of the stainless steel pipeline and the second receiving kettle 12 is below 1 Pa, sequentially and slowly close the first valve 14, the second valve 15 and the vacuum pump 6, and then open the refrigerant tank to fill a certain amount of refrigerant into the second receiving kettle 12.

[0103] S3. Fill 200 to 400 ml of lubricating oil into the first receiving kettle 11. After sealing the first receiving kettle 11, turn on the temperature control unit 10 to keep the temperature in the system cavity 9 at 60 °C. Close the first valve 14, turn on the vacuum pump 6, open the second valve 15, the third valve 16, the twelfth valve 612 and the thirteenth valve 613 in sequence, turn on the magnetic stirrer 81, and adjust the rotation speed of the magnetic stirrer 81 to 100 rpm to accelerate the discharge of the air and other impurities dissolved in the lubricating oil. When the vacuum degree drops below 1 Pa, close the second valve 15, the third valve 16, the vacuum pump 6 and the magnetic stirrer 81 slowly in sequence.

[0104] S4. Turn on the temperature controller and keep the system cavity 9 at the temperature to be measured. Slowly open the first valve 14 and the third valve 16 in sequence, and fill a certain amount of refrigerant from the second receiving kettle 12 into the first receiving kettle 11. Close the first valve 14 and the third valve 16. Turn on the magnetic stirrer 81 to accelerate the gas-liquid phase equilibrium process in the first receiving kettle 11. At the same time, observe the pressure in the first receiving kettle 11, that is, the indication of the first pressure sensor 91. When the pressure in the first receiving kettle 11 is stable, it indicates that the refrigerant has been fully dissolved in the lubricating oil. Record the equilibrium pressure and temperature at this time. Turn off the magnetic stirrer 81. After the state of the refrigerant-lubricating oil saturated solution in the first receiving kettle 11 is stable, read the indication ρ of the density sensor 111.

[0105] S5. Turn on the magnetic pump 23 and set the initial flow rate Q. When measuring low-viscosity lubricating oil, open the fourth valve 26, the fifth valve 27, the eighth valve 1121 and the ninth valve 1122 in sequence. When the viscosity of the refrigerant-lubricating oil saturated solution is relatively high, open the fourth valve 26, the fifth valve 27, the sixth valve 28 and the seventh valve 29 in sequence, and at the same time adjust the opening degree of the tenth valve 210 so that the pressure at the second pressure sensor 81 is slightly greater than the pressure at the first pressure sensor 39. When the refrigerant-lubricating oil saturated solution flows in the pipeline of the first measuring unit 2 for a period of time and the refrigerant-lubricating oil saturated solution stably flows into the collecting bottle 25, close the tenth valve 210 and open the eleventh valve 223 to carry out the internal circulation between the first measuring unit 2 and the first receiving kettle 11. Observe the indication of the first differential pressure sensor 212 or the second differential pressure sensor 222. After the differential pressure value on both sides of the first capillary 211 or the second capillary 221 is stable, read the differential pressure ΔP, and thus a measurement of data is completed.

[0106] S6. According to the measured data, we can calculate the dynamic viscosity of the refrigerant-lubricating oil saturated solution through the formula and then, based on the relationship between the kinematic viscosity and the dynamic viscosity, combined with the measured density data of the refrigerant-lubricating oil saturated solution, through the formula The kinematic viscosity value of the refrigerant-lubricant saturated solution can be calculated accordingly.

[0107] S7. Close the twelfth valve 42 and the thirteenth valve 43, remove the collection tank 41, clean the outside of the collection tank 41 with absolute ethanol and then dry it. Measure the mass of the collection tank 41 at this time on the weighing device as m1. Open the thirteenth valve 43, place the collection tank 41 on the magnetic stirrer 81 to accelerate the escape of the refrigerant not dissolved in the lubricant. After the refrigerant is completely released, measure the mass of the collection tank 41 as m2. It is known that the mass of the clean collection tank 41 and the second magnetic rotor 82 is m3, and the mass solubility of the refrigerant-lubricant saturated solution

[0108] S8. Due to the surface tension of the refrigerant-lubricant saturated solution, the liquid levels in the third capillary 32 and the fourth capillary 33 will be higher than the liquid level in the first receiving kettle 11. Use the photographic equipment 36 to take pictures of the liquid level heights of the third capillary 32 and the fourth capillary 33. Obtain the number of unit pixels between the liquid levels of the third capillary 32 and the fourth capillary 33 in the picture as n. The liquid level height difference between the third capillary 32 and the fourth capillary 33 is Δh = n·a. The surface tension of the refrigerant-lubricant saturated solution can be calculated through the formula where ρ g is the gas phase density in the first receiving kettle 11, g is the acceleration due to gravity, and ρ is the pressure value P1 measured by the first pressure sensor 91.

[0109] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A measuring device, characterized in that, The measurement device includes a containment unit, a first measurement unit, a second measurement unit, and a third measurement unit that are respectively connected to the containment unit; The containment unit is used to contain the refrigerant-lubricant saturated solution; The first measurement unit is used to measure the viscosity of the refrigerant-lubricant saturated solution output by the containment unit. The first measurement unit includes a first measurement subunit and a second measurement subunit. Both the first measurement subunit and the second measurement subunit are connected to the containment unit. The first measurement subunit is used to measure the viscosity of the low-viscosity refrigerant-lubricant saturated solution, and the second measurement subunit is used to measure the viscosity of the high-viscosity refrigerant-lubricant saturated solution. The first measurement subunit has a conducting state and a disconnected state. The first measurement unit further includes a control unit and a sixth valve. The control unit is connected to the first measurement subunit. The sixth valve is arranged between the containment unit and the first measurement subunit. The sixth valve is used to control the on-off of the connection path between the containment unit and the first measurement subunit. The control unit is used to control the first measurement subunit to switch between the conducting state and the disconnected state. The control unit includes an auxiliary path and a valve. The auxiliary path is connected in parallel at both ends of the first measurement subunit, and the sixth valve is arranged in parallel with the auxiliary path. The valve is arranged on the auxiliary path and is used to control the on-off of the auxiliary path. The first measurement unit further includes a back pressure valve. The back pressure valve is arranged at one end of the second measurement subunit away from the first measurement subunit. The back pressure valve is used to adjust the outlet back pressure of the second measurement subunit. When the first measurement subunit is in the conducting state, the containment unit, the first measurement subunit, and the second measurement subunit are sequentially connected to form a first path, so that the first measurement subunit measures the viscosity of the low-viscosity refrigerant-lubricant saturated solution flowing through the first path. When the first measurement subunit is in the disconnected state, the containment unit, the control unit, and the second measurement subunit are sequentially connected to form a second path, so that the second measurement subunit measures the viscosity of the high-viscosity refrigerant-lubricant saturated solution flowing through the second path; The second measurement unit is used to measure the surface tension of the refrigerant-lubricant saturated solution output by the containment unit; The third measurement unit is used to measure the solubility of the refrigerant-lubricant saturated solution output by the containment unit.

2. The measuring device according to claim 1, characterized in that, The containment unit includes a first containment kettle and a second containment kettle. The first measurement unit, the second measurement unit, and the third measurement unit are all connected to the first containment kettle. The first containment kettle is connected to the second containment kettle. The first containment kettle is used to contain lubricating oil, and the second containment kettle is used to contain refrigerant. The first containment kettle is further used to contain the refrigerant-lubricant saturated solution obtained after mixing the refrigerant output by the second containment kettle and the lubricating oil.

3. The measuring device according to claim 1, characterized in that, The first measurement unit includes a first capillary tube and a first differential pressure sensor. The first capillary tube has a first inlet end and a first outlet end. The first inlet end of the first capillary tube is connected to the receiving unit, and the refrigerant-lubricant saturated solution with a preset flow rate output by the receiving unit can flow into the first capillary tube through the first inlet end of the first capillary tube and flow out of the first capillary tube through the first outlet end of the first capillary tube. The ratio of the length to the inner diameter of the first capillary tube is not less than a preset value. One end of the first differential pressure sensor is connected to the first inlet end, and the other end of the first differential pressure sensor is connected to the first outlet end. The first differential pressure sensor is used to measure the pressure difference between the first inlet end and the first outlet end.

4. The measuring device according to claim 1, characterized in that, The second measurement unit includes a third capillary tube, a fourth capillary tube, a scale, a density sensor, and a first pressure sensor. The third capillary tube, the fourth capillary tube, and the scale are arranged vertically side by side in the receiving unit. The inner diameters of the third capillary tube and the fourth capillary tube are different. The refrigerant-lubricant saturated solution output by the receiving unit can enter the third capillary tube through the inlet end of the third capillary tube and flow along the inner side wall of the third capillary tube. The refrigerant-lubricant saturated solution can also enter the fourth capillary tube through the inlet end of the fourth capillary tube and flow along the inner side wall of the fourth capillary tube. The scale is used to indicate the liquid level height of the refrigerant-lubricant saturated solution in the third capillary tube and the fourth capillary tube. The density sensor is connected to the receiving unit, and the density sensor is used to measure the density of the refrigerant-lubricant saturated solution in the receiving unit. The first pressure sensor is connected to the receiving unit, and the first pressure sensor is used to measure the pressure of the refrigerant-lubricant saturated solution in the receiving unit.

5. The measuring device according to claim 1, characterized in that, The third measurement unit includes a collection tank and a weighing device. The collection tank is connected to the receiving unit. The collection tank is used to receive the refrigerant-lubricant saturated solution output by the receiving unit. The weighing device is used to measure the mass of the collection tank.

6. The measuring device according to claim 1, characterized in that, The measurement device further includes a system cavity. The receiving unit, the first measurement unit, the second measurement unit, and the third measurement unit are all arranged in the system cavity.

Images