JP2016090304A - Liquid detector, compressor and air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid detector, compressor with the liquid detector and air conditioner with the compressor that can correctly calculate a degree of dilution of a liquid in a container.SOLUTION: A temperature detection circuit is configured to transmit a voltage signal in accordance with a temperature of a liquid to a microcomputer μCOM, and a static capacitance detection circuit is configured to a voltage signal in accordance with a static capacitance to the μCOM; and a CPU of the μCOM is configured to calculate a degree of dilution of the liquid on the basis of the temperature and static capacitance. Only the static capacitance is measured but also the temperature is measured, and thereby the degree of dilution of the liquid can be correctly calculated on the basis of the static capacitance and the temperature.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a capacitance-type liquid detector used for detecting liquid contained in a container, a compressor including the liquid detector, and an air conditioner including the compressor.

  The air conditioner includes an outdoor heat exchanger and an indoor heat exchanger, and an expansion valve and a compressor provided therebetween. In the refrigeration cycle of an air conditioner, for example, the liquid refrigerant that has passed through the outdoor heat exchanger becomes gaseous by the expansion valve, and the temperature is lowered to cool air, which is led to the indoor heat exchanger. The gaseous refrigerant having transferred heat (low temperature) to the indoor heat exchanger is compressed by the compressor to be in a high temperature / high pressure state, and becomes liquid again by transferring heat (high temperature) to the outdoor heat exchanger.

  As a compressor used in such an air conditioner, there is a compressor adopting a rotary method or a scroll method. For example, in a rotary compressor disclosed in Patent Document 1, a compression unit having a cylinder in which a working chamber is formed and an annular piston accommodated in the working chamber is disposed in a tank-like compressor housing. The annular piston is rotated while a part of the outer peripheral surface is in contact with the peripheral wall surface of the working chamber, whereby the refrigerant introduced into the working chamber is compressed.

  In the compressor disclosed in Patent Document 1, lubricating oil is enclosed in a compressor housing for lubrication of sliding parts such as a cylinder and a piston and sealing (sealing) of a minute gap. And if this lubricating oil becomes less than a predetermined amount for some reason, it will hinder the operation of the compressor, so it is necessary to monitor the amount of lubricating oil. For example, Patent Document 2 discloses a sensor that can be used for monitoring the amount of such lubricating oil.

  In the sensor described in Patent Document 2, the pair of electrode plates are fixed by spacers, so that when the electrode plates are stressed, they are not easily deformed, and the distance between the electrode plates varies. Reduces measurement accuracy.

JP 2012-207585 A JP 2013-92491 A

  By the way, the refrigerant compressed by the compressor may enter the housing and mix with the lubricating oil. Lubricating oil diluted by the mixing of such refrigerant deteriorates lubrication performance and sealing performance. Therefore, it is necessary to remove the refrigerant when the degree of dilution is high (the concentration of the lubricating oil is low). Therefore, in the liquid detector described in Patent Document 2, a configuration for determining the dilution of the lubricating oil based on the measured capacitance can be considered, but the relationship between the capacitance and the dilution depends on the temperature. It is difficult to accurately determine the degree of dilution with such a configuration.

  The objective of this invention is providing the liquid detector which can calculate the dilution degree of the liquid in a container correctly, the compressor provided with this liquid detector, and the air conditioner provided with this compressor. .

  In order to solve the above-mentioned problems and achieve the object, the invention described in claim 1 is a capacitive liquid detector used for detecting a liquid contained in a container, and is parallel to each other and predetermined. A plurality of electrode plates arranged in parallel so as to face each other at intervals, a capacitance measuring means for measuring a capacitance between the plurality of electrode plates, and a temperature measuring means for measuring the temperature of the liquid Dilution calculation for calculating the dilution of the liquid due to mixing of other liquids based on the capacitance measured by the capacitance measurement means and the temperature of the liquid measured by the temperature measurement means And a liquid detector.

  The invention described in claim 2 is characterized in that, in the invention described in claim 1, the dilution calculation means corrects the dilution based on the type of the other liquid.

  The invention described in claim 3 is the invention described in claim 1 or 2, further comprising a viscosity calculating means for calculating the viscosity of the liquid based on the temperature and the dilution. Is.

  The invention described in claim 4 is characterized in that, in the invention described in claim 3, the viscosity calculating means corrects the viscosity based on the type of the other liquid.

  According to a fifth aspect of the present invention, there is provided a casing, a liquid detection unit that detects lubricating oil as a liquid contained in a container included in the casing, and a refrigerant as another liquid provided in the casing. A compressor having a compression section that compresses the liquid, wherein the liquid detection section includes the liquid detector according to any one of claims 1 to 4. Machine.

  The invention described in claim 6 is an air conditioner including a refrigerant circuit including an indoor heat exchanger, an outdoor heat exchanger, an expansion valve, and a compressor, wherein the compressor is described in claim 5. It is an air conditioner characterized by comprising a compressor.

  According to the invention described in claims 1, 5, and 6, not only the capacitance is measured by the capacitance measuring unit, but also the temperature and the temperature are measured by the temperature measuring unit, so that the capacitance and the temperature are changed. Based on this, the degree of dilution of the liquid can be accurately calculated.

  According to the invention described in claim 2, when other liquid mixed in the liquid is known, the dilution can be calculated more accurately by correcting the dilution according to the type of the liquid. it can.

  According to the invention described in claim 3, the viscosity of a liquid mixed with another liquid can be calculated. When this liquid is, for example, a lubricating oil, the lubricating performance varies depending on the viscosity. Therefore, the viscosity can be monitored so that the lubricating oil has a desired lubricating performance.

  According to the invention described in claim 4, when other liquid mixed in the liquid is known, the viscosity can be calculated more accurately by correcting the viscosity according to the type of the liquid.

It is a front view of the liquid detection unit which has a detection element part concerning one embodiment of the present invention. It is sectional drawing which follows the XX line of FIG. It is a rear view of the detection element part which the liquid detection unit of FIG. 1 has. It is a front view of the detection control part which the liquid detection unit of FIG. 1 has. It is a figure which shows the outline of the electric circuit of the detection element part which the liquid detection unit of FIG. 1 has. It is a figure which shows the outline of the electric circuit of the liquid detection unit of FIG. It is sectional drawing of the compressor which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of the air conditioner which concerns on one Embodiment of this invention.

(Embodiment of liquid detector)
Hereinafter, a liquid detection unit having a liquid detector according to an embodiment of the present invention will be described with reference to FIGS. For example, the liquid detection unit is attached to a side wall of a casing of a compressor, which will be described later, detects the liquid level of the lubricating oil contained in the casing, and is lubricated with impurities (refrigerant). It is used to determine the dilution and viscosity.

  FIG. 1 is a front view of a liquid detection unit having a detection element unit according to an embodiment of the present invention. 2 is a cross-sectional view taken along line XX of FIG. FIG. 3 is a rear view of the detection element unit included in the liquid detection unit of FIG. FIG. 4 is a front view of a detection control unit included in the liquid detection unit of FIG. FIG. 5 is a diagram showing an outline of an electric circuit of a detection element unit included in the liquid detection unit of FIG. FIG. 6 is a diagram showing an outline of an electric circuit of the liquid detection unit of FIG.

  As shown in FIGS. 1 to 4, this liquid detection unit (indicated by reference numeral 1 in the figure) has a detection element unit 10 as a liquid detector and a detection control unit 50 (FIG. 2). . The detection element unit 10 and the detection control unit 50 are configured to be fitted to each other as a pair of connectors.

  The detection element unit 10 includes a base 20, a plurality of conductive terminals 30, a pair of electrode plates 40, and a temperature detection unit 90.

  The base 20 is made of, for example, a metal such as stainless steel, and integrally includes a base main body portion 21, a cylindrical portion 22, and a flange portion 23, and a plurality of conductive materials described later. A hermetic glass 24 for fixing the terminal 30 and the temperature detection unit 90 is provided.

  The base main body 21 is formed in a disc shape. The cylindrical portion 22 is provided so as to protrude from one surface 21 a of the base body 21 so as to be coaxial with the base body 21. A plurality of through holes 21c penetrating the one surface 21a and the other surface 21b are formed at a location inside the cylindrical portion 22 in the base main body portion 21. The flange portion 23 is provided over the entire peripheral surface 21 d of the base main body portion 21 so as to protrude in the radial direction of the base main body portion 21. The attachment surface 23a facing the same direction as the other surface 21b of the base main body portion 21 in the flange portion 23 is an annular flat surface, and is attached to the case 102 of the compressor 101 to be described later. It surrounds the through-hole 103a provided in the part 103, and is arrange | positioned so that the whole may contact the outer surface of the said side wall part 103 closely. The hermetic glass 24 is fixed in the plurality of through holes 21c.

  The plurality of conductive terminals 30 are made of, for example, a conductive metal such as a nickel alloy, and are each formed in a rod shape that extends straight. Each of the plurality of conductive terminals 30 is inserted through the corresponding through hole 21c, and is fixedly attached to the base body 21 while being electrically insulated from the base body 21 by the hermetic glass 24. Yes. In order to fix the conductive terminal 30 to the base body portion 21, another insulating material may be used instead of the hermetic glass 24. Each of the plurality of conductive terminals 30 is arranged so that each part 31 protrudes perpendicularly from the other surface 21b of the base body 21 and the other part 32 protrudes perpendicularly from one surface 21a. The other part 32 of each conductive terminal 30 is brought into contact with the female terminal of the detection control unit 50 as a male terminal when fitted with the detection control unit 50 described later.

  In the present embodiment, six conductive terminals 30 are included, and two types of lengths are included. Specifically, three of the plurality of conductive terminals are formed long (indicated by reference numeral 30L in the figure), and the remaining three are formed shorter than these three (indicated by reference numeral 30S in the figure). . The three conductive terminals 30L and the remaining three conductive terminals 30S are alternately arranged in the circumferential direction so as to be the apexes of a regular hexagon as viewed from the front. The plurality of conductive terminals 30 (30L, 30S) are fixed to the base main body portion 21 so that the lengths of the other portions 32 thereof are the same, whereby one of the three conductive terminals 30L. The part 31 and the part 31 of the remaining three conductive terminals 30 </ b> S have different lengths.

  The pair of electrode plates 40 is made of, for example, a conductive metal such as stainless steel, and each is formed in the same disc shape. One electrode plate 40L of the pair of electrode plates 40 is fixedly attached to the tip of each of the three conductive terminals 30L described above, and the other electrode plate 40S includes the remaining three electrode plates 40S. Each conductive terminal 30S is fixedly attached to the tip of each part 31 thereof. A through hole 40a through which the three conductive terminals 30L are inserted is provided at a position corresponding to the three conductive terminals 30L in the other electrode plate 40S. Each through hole 40a is filled with a mold resin or the like (not shown), and the conductive terminal 30L and the electrode plate 40S are insulated. Each electrode plate 40 is attached to each conductive terminal 30 by, for example, welding or brazing. Thus, by attaching one electrode plate 40L and the other electrode plate 40S to the respective tips of the part 31 of the conductive terminal 30L and the part of the conductive terminal 30S having different lengths, these electrode plates 40L, 40S are arranged in parallel with a space between each other. The electrode plates 40L and 40S are also arranged in parallel with the mounting surface 23a of the flange portion 23.

  The temperature detector 90 is, for example, a rod-shaped thermocouple in which appropriate metals are combined, and is inserted through the through hole 21c and is electrically insulated from the base body 21 by the hermetic glass 24. It is fixedly attached to the part 21. The temperature detection unit 90 includes a detection unit 91 that protrudes perpendicularly from the other surface 21b of the base body 21 and a connection unit 92 that protrudes perpendicularly from the one surface 21a. The connecting portion 92 is brought into contact with the female terminal of the detection control unit 50 as a male terminal when fitted with the detection control unit 50 described later. The temperature detection unit 90 is arranged such that the detection unit 91 is disposed below the electrode plate 40, and when the liquid level reaches the lower end of the electrode plate 40, the temperature detection unit 90 can always be in contact with the liquid and measure the temperature. It has become. The temperature detection unit 90 is not limited to a thermocouple, and may be a sensor such as a resistance temperature detector.

  The detection control unit 50 includes a housing 60, a case 70, and a control board 80.

  The housing 60 is made of, for example, a synthetic resin, and integrally includes a housing main body 61, a cylindrical portion 62, and a substrate housing portion 63, and further includes a seal member 64. Yes. The substrate accommodating portion 63 may be of any shape as long as it can accommodate a control substrate 80 to be described later, such as a cylindrical shape.

  The housing main body 61 is formed in a disc shape. The cylindrical portion 62 is provided so as to protrude from one surface 61 a of the housing main body 61 so as to be coaxial with the housing main body 61. The cylindrical part 62 has an outer diameter substantially the same as the inner diameter of the cylindrical part 22 so that the cylindrical part 62 is accommodated in the cylindrical part 22 of the detection element part 10 when fitted, and its height is substantially equal to the depth of the cylindrical part 22. Are the same. The cylindrical portion 62 has a terminal hole 62b that opens to a location corresponding to the plurality of conductive terminals 30 on its end surface 62a and accommodates a female terminal (not shown), and opens to a location corresponding to the temperature detection portion 90 and a female. A terminal hole 62c for receiving a terminal (not shown) is formed. The substrate housing portion 63 is provided on the other surface 61 b of the housing main body 61 so as to protrude in a square tube shape. The substrate accommodating portion 63 may be of any shape as long as it can accommodate a control substrate 80 to be described later, such as a cylindrical shape.

  The seal member 64 is formed in an annular shape using, for example, silicone rubber or the like, and is partially embedded in one surface 61 a of the housing main body 61 so as to surround the cylindrical portion 22. The seal member 64 is crushed by the end surface 22a of the cylindrical portion 22 of the detection element unit 10 when fitted, and seals (seal) between the detection element unit 10 and the detection control unit 50.

  The case 70 is made of, for example, a synthetic resin, and integrally includes a cylindrical peripheral wall portion 71 and a bottom wall portion 72 that closes one end of the peripheral wall portion 71.

  The inner diameter of the peripheral wall 71 is substantially the same as the outer diameter of the cylindrical portion 22 so as to accommodate the cylindrical portion 22 of the detection element portion 10 when fitted. Further, a locking claw (not shown) that locks into a locking receiving hole (not shown) formed on the outer peripheral surface of the cylindrical portion 22 when fitted is formed on the inner peripheral surface of the peripheral wall portion 71 so as to protrude. Yes. The bottom wall portion 72 is formed with a fitting hole 72a formed in substantially the same shape (in the present embodiment, a square shape) as the planar view shape of the substrate housing portion 63 so that the substrate housing portion 63 can be fitted therein. Has been.

  The control board 80 includes a capacitance detection circuit that transmits a voltage signal according to the value of the capacitance between the pair of electrode plates 40, a temperature detection circuit that transmits a voltage signal according to the value of the temperature of the liquid, It is an electronic board in which various electronic components constituting a microcomputer (hereinafter referred to as μCOM) to which these voltage signals are input are mounted on a printed board. The control board 80 is housed and fixed in the board housing part 63 and is connected to a host control device (not shown) (for example, a control device for an oil separation device described later) through a lead wire 85. The capacitance detection circuit of the control board 80 is connected to a female terminal (not shown) accommodated in the terminal hole 62b, and this female terminal is connected to the other part 32 (that is, a male terminal) of the conductive terminal 30. In the contacted state, a voltage signal corresponding to the capacitance between the pair of electrode plates 40 is transmitted to the μCOM. The control board 80 outputs a voltage signal corresponding to the capacitance based on, for example, a time constant or a resonance frequency in a resonance circuit.

  The temperature detection circuit of the control board 80 is connected to a female terminal (not shown) accommodated in the terminal hole 62c, and the female terminal is in contact with the connection portion 92 (that is, the male terminal) of the temperature detection portion 90. In FIG. 2, the detection unit 91 of the temperature detection unit 90 is configured to transmit a signal corresponding to the temperature of the liquid or gas that is in contact with the μCOM. The CPU of μCOM functions as a capacitance measuring means by measuring the capacitance based on the voltage signal input from the capacitance detection circuit, and temperature based on the voltage signal input from the temperature detection circuit. Functions as a temperature measuring means. The μCOM is configured to output a signal through the lead wire 85 according to the measured capacitance and the dilution and viscosity of the liquid calculated as described later.

  The detection element unit 10 and the detection control unit 50 are fitted closer to each other from the state shown in FIG. 2, so that the conductive terminal 30 (male terminal) of the detection element unit 10 and the housing 60 of the detection control unit 50 are included. And the female terminal in the housing 60 of the detection control unit 50 are in electrical contact with each other and the temperature detection unit 90 (male terminal) of the detection element unit 10 is in contact with the female terminal. Thus, the liquid detection unit 1 is configured to output a detection signal corresponding to the capacitance between the pair of electrode plates 40, the dilution of the liquid, and the viscosity of the liquid.

  As shown in FIG. 5, the sensing element unit 10 can be regarded as a capacitor that stores electric charges between a pair of electrode plates 40. Then, as shown in FIG. 6, the liquid detection unit 1 measures the capacitance between the pair of electrode plates 40 and outputs a detection signal corresponding to the measured capacitance. Based on this detection signal, the presence or absence of liquid at the height at which the detection element unit 10 is attached, that is, the liquid level can be detected.

  Next, a procedure in which the control substrate 80 having the capacitance detection circuit and the temperature detection circuit calculates the dilution and viscosity of the liquid will be described.

  When the CPU of μCOM detects a liquid based on the measured capacitance, the dilution of the liquid (that is, other liquids in the mixed liquid of the liquid and the other liquid) based on the measured temperature and the capacitance. (Concentration of liquid) is calculated and functions as a dilution degree calculation means. At this time, the μCOM storage area stores, for example, the dependency of the dilution on the capacitance and temperature as a table, and the μCOM CPU applies the measured capacitance and temperature to this table. Calculate the dilution with. Further, when the type of other liquid is known, the CPU corrects the calculated dilution by multiplying the calculated dilution by a coefficient corresponding to the type of the other liquid. If the temperature is equal to or higher than a predetermined value, it is determined that another liquid is vaporized, and the dilution level is set to zero.

  Furthermore, the CPU of μCOM calculates the viscosity of the liquid based on the dilution degree calculated as described above and the measured temperature, and functions as a viscosity calculation unit. At this time, the μCOM storage area stores, for example, viscosity dilution and temperature dependency as a table, and the μCOM CPU applies the measured temperature and the calculated dilution to this table. Viscosity is calculated. Further, when the type of other liquid is known, the CPU corrects the calculated viscosity by multiplying the coefficient according to the type of the other liquid.

  As described above, according to the present embodiment, not only by measuring the capacitance, but also by measuring the temperature, the dilution of the liquid can be accurately calculated based on the capacitance and the temperature. At this time, the dilution can be calculated more accurately by correcting the dilution according to the type of the other liquid.

  In the embodiment described above, the dilution is calculated by applying capacitance and temperature to the table, and the viscosity is calculated by applying dilution and temperature to the table. The degree of dilution may be calculated and the degree of dilution may be corrected based on the temperature, or the viscosity may be calculated based on the degree of dilution and the viscosity may be corrected based on the temperature. In addition, the μCOM CPU multiplies the coefficient according to the type of other liquid to correct the dilution and viscosity. However, the dilution and viscosity are calculated for each type of other liquid in the μCOM storage area. A table for storing data may be stored, and the dilution degree and viscosity may be calculated by selecting the table according to the liquid mixed in by the CPU. Further, when the influence on the degree of dilution and viscosity due to the type of other liquid is small, the correction according to the type of the other liquid may not be performed.

  In the above-described embodiment, the capacitance detection circuit calculates the viscosity. However, for example, when the liquid detection unit 1 is attached to a container containing fuel as a liquid, the measurement of the viscosity of the liquid is performed. If the capacitance is not required, the capacitance detection circuit may not be configured to calculate the viscosity.

(Embodiment of compressor)
Below, the compressor which concerns on one Embodiment of this invention is demonstrated with reference to FIG. FIG. 7 is a cross-sectional view of a compressor according to an embodiment of the present invention. This compressor is provided in a refrigerant circuit of an air conditioner, for example, and is used for circulation of the refrigerant in the refrigerant circuit.

  The compressor 101 employs a rotary system and is housed in a housing 102 in a motor unit 110 having a motor stator 111 and a motor rotor 112, a cylinder 121, and a working chamber 122 formed in the cylinder 121. And a compression portion 120 having an annular piston 125. The motor rotor 112 and the annular piston 125 are connected by a crankshaft 130. The lower portion of the housing 102 contains lubricating oil K for lubricating the compression portion 120 and the like, and a portion of the housing 102 in which the lubricating oil K is housed functions as a container 102a. The side wall 103 of the housing 102 is the side wall.

  When the crankshaft 130 is rotated by the motor unit 110, the compressor 101 is rotated while the annular piston 125 is in contact with the peripheral wall surface of the working chamber 122. In accordance with the rotation of the annular piston 125, the refrigerant is introduced into the working chamber 122 from the suction pipe 141 through the suction muffler 142 and the introduction pipe 143. Then, the refrigerant is compressed by the annular piston 125 in the working chamber 122 and led out of the compressor 101 through the discharge muffler 144, the casing 102, and the discharge pipe 145.

  The compressor 101 has the liquid detection unit 1 described above. The detection element portion 10 of the liquid detection unit 1 is attached to the side wall portion 103 along the vertical direction in the housing 102. Specifically, in the detection element unit 10, a part 31 of the plurality of conductive terminals 30 and a pair of electrode plates 40 are inserted into a through hole 103 a provided in the side wall unit 103, and the flange portion 23 of the base 20 is formed. The flange portion 23 is fixed by welding in a state where the entire mounting surface 23a is in contact with the outer surface of the side wall portion 103 around the through hole 103a.

  The refrigerant circuit includes a control device (not shown) connected to the control board 80 by a lead wire 85, and an oil separation (not shown) that separates the lubricating oil K from the refrigerant circulating in the refrigerant circuit and returns it to the container 102a of the compressor 101. A device is provided. The control device is configured to be able to control the oil separation device, and the lubricating oil K is used as a liquid and the refrigerant is used as another liquid, the signal regarding the dilution of the lubricating oil K due to the mixing of the refrigerant, and the viscosity of the lubricating oil K. The signal is received. When the dilution degree of the lubricating oil K becomes higher than a predetermined value (that is, when the amount of mixed refrigerant increases), it is considered that the lubricating oil K has also flowed into the refrigerant circuit. The apparatus operates the oil separator to separate the lubricating oil K from the refrigerant and return it to the container 102a. Furthermore, the control device prompts replacement or maintenance of the lubricating oil K by generating an alarm or the like when the lubricating oil K has a viscosity that does not satisfy the predetermined lubricating performance or sealing performance. In addition, while the apparatus which removes a refrigerant | coolant from the lubricating oil K in the container 102a is provided, the structure which a control means operates this apparatus according to a dilution degree or a viscosity may be sufficient.

  The pair of electrode plates 40 of the detection element unit 10 are arranged in parallel to each other along the vertical direction in the container 102a. In the normal state where the lubricant oil K is in an appropriate amount, the detection element unit 10 sinks below the liquid level in a normal state, and a part of the pair of electrode plates 40 in the abnormal state where the lubricant oil K is insufficient. It is arrange | positioned so that the whole may be exposed on a liquid level.

  As described above, according to the present embodiment, since the oil separator is operated according to the dilution degree of the lubricating oil K, the lubricating oil K in the container 102a can be maintained at a predetermined amount or more. In addition, the oil separation device is not operated when it is unnecessary, as compared with a configuration in which the removal device is periodically operated without measuring the degree of dilution.

  Further, by promoting replacement and maintenance according to the viscosity of the lubricating oil K, the lubricating performance and the sealing performance can be maintained. At this time, the viscosity can be calculated more accurately by correcting the viscosity according to the type of the other liquid.

  In the above-described embodiment, the rotary system is used. However, the present invention is not limited to this. For example, a structure using another system such as a scroll system may be used.

(Embodiment of air conditioner)
Below, the air conditioner which concerns on one Embodiment of this invention is demonstrated with reference to FIG. FIG. 8 is a diagram showing a schematic configuration of an air conditioner according to an embodiment of the present invention. This air conditioner is used, for example, as an air conditioner provided in a house or a commercial facility.

  The air conditioner 201 includes a refrigerant circuit 210 including an indoor heat exchanger 211, an outdoor heat exchanger 212, an expansion valve 213, the compressor 101 described above, and a flow path switching valve 215.

  The flow path of the refrigeration cycle of the air conditioner 201 is switched to two flow paths of “cooling mode” and “heating mode” by the flow path switching valve 215. In the cooling mode, as indicated by solid arrows in FIG. 8, the refrigerant compressed by the compressor 101 flows into the outdoor heat exchanger 212 from the flow path switching valve 215 and into the expansion valve 213. Then, the refrigerant is expanded by the expansion valve 213 and flows into the indoor heat exchanger 211. The refrigerant that has flowed into the indoor heat exchanger 211 flows into the compressor 101 via the flow path switching valve 215. On the other hand, in the heating mode, as indicated by broken arrows in FIG. 8, the refrigerant compressed by the compressor 101 flows from the flow path switching valve 215 into the indoor heat exchanger 211 and flows into the expansion valve 213. Then, the refrigerant is expanded by the expansion valve 213 and circulated in the order of the outdoor heat exchanger 212, the flow path switching valve 215, and the compressor 101.

  In the cooling mode, the outdoor heat exchanger 212 functions as a condenser, the indoor heat exchanger 211 functions as an evaporator, and indoor cooling is performed. In the heating mode, the outdoor heat exchanger 212 functions as an evaporator, the indoor heat exchanger 211 functions as a condenser, and the room is heated.

  As described above, according to the present embodiment, since the compressor 101 having the liquid detection unit 1 capable of calculating the dilution and viscosity of the lubricating oil K as described above is provided, the problem of the compressor 101 is suppressed. Therefore, it is possible to suppress problems of the entire air conditioner 201 and to enable stable operation.

  In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to embodiment. That is, those skilled in the art can implement various modifications in accordance with conventionally known knowledge without departing from the scope of the present invention. Of course, such modifications are included in the scope of the present invention as long as the liquid detector, the compressor and the air conditioner of the present invention are provided.

1 Liquid detection unit 10, 10A, 10B Detection element (liquid detector)
DESCRIPTION OF SYMBOLS 20 Base 23a Mounting surface 40 Electrode plate 50 Detection control part 90 Temperature detection part 101 Compressor 102 Case 102a Container 103 Side wall part 103a Through hole 201 Air conditioner 210 Refrigerant circuit 211 Indoor heat exchanger 212 Outdoor heat exchanger 213 Expansion valve 215 Channel switching valve K Lubricating oil

Claims (6)

A capacitance type liquid detector used for detecting liquid contained in a container,
A plurality of electrode plates arranged parallel to each other and facing each other with a gap in a predetermined direction;
A capacitance measuring means for measuring a capacitance between the plurality of electrode plates;
Temperature measuring means for measuring the temperature of the liquid;
Dilution calculation means for calculating the dilution of the liquid due to mixing of other liquids based on the capacitance measured by the capacitance measurement means and the temperature of the liquid measured by the temperature measurement means; And a liquid detector.   The liquid detector according to claim 1, wherein the dilution calculation unit corrects the dilution based on the type of the other liquid.   The liquid detector according to claim 1, further comprising a viscosity calculating unit that calculates the viscosity of the liquid based on the temperature and the dilution.   The liquid detector according to claim 3, wherein the viscosity calculating unit corrects the viscosity based on a type of the other liquid. Compression having a casing, a liquid detection unit that detects lubricating oil as a liquid contained in a container of the casing, and a compression unit that is provided in the casing and compresses a refrigerant as another liquid Machine,
The said liquid detection part is comprised including the liquid detector of any one of Claims 1-4, The compressor characterized by the above-mentioned.   An air conditioner including a refrigerant circuit including an indoor heat exchanger, an outdoor heat exchanger, an expansion valve, and a compressor, wherein the compressor is configured by the compressor according to claim 5. Air conditioner.

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