Patent Application
20220404070
The present invention relates to an air conditioner that uses refrigerant with a low global warming potential (GWP).
In recent years, use of refrigerant with a low GWP (hereinafter referred to as low-GWP refrigerant) in air conditioners has been considered from the viewpoint of environmental protection. A dominant example of low-GWP refrigerant is a refrigerant mixture containing 1,2-difluoroethylene.
However, the related art giving consideration from the aspect of increasing the efficiency of air conditioners using the foregoing refrigerant is rarely found. For example, in the case of applying the foregoing refrigerant to the air conditioner disclosed in PTL 1 (Japanese Unexamined Patent Application Publication No. 2013-124848), there is an issue of how to achieve high efficiency.
An air conditioner according to a first aspect includes a compressor that compresses a refrigerant mixture containing at least 1,2-difluoroethylene, a motor that drives the compressor, and a power conversion device. The power conversion device is connected between an alternating-current (AC) power source and the motor, has a switching element, and controls the switching element such that an output of the motor becomes a target value.
In the air conditioner that uses a refrigerant mixture containing at least 1,2-difluoroethylene, the motor rotation rate of the compressor can b e changed in accordance with an air conditioning load, and thus a high annual performance factor (APF) can be achieved.
An air conditioner according to a second aspect is the air conditioner according to the first aspect, in which the power conversion device includes a rectifier circuit and a capacitor. The rectifier circuit rectifies an AC voltage of the AC power source. The capacitor is connected in parallel to an output side of the rectifier circuit and smooths voltage variation caused by switching in the power conversion device.
In this air conditioner, an electrolytic capacitor is not required on the output side of the rectifier circuit, and thus an increase in the size and cost of the circuit is suppressed.
An air conditioner according to a third aspect is the air conditioner according to the first aspect or the second aspect, in which the AC power source is a single-phase power source.
An air conditioner according to a fourth aspect is the air conditioner according to the first aspect or the second aspect, in which the AC power source is a three-phase power source.
An air conditioner according to a fifth aspect is the air conditioner according to the first aspect, in which the power conversion device is an indirect matrix converter including a converter and an inverter. The converter converts an AC voltage of the AC power source into a direct-current (DC) voltage. The inverter converts the DC voltage into an AC voltage and supplies the AC voltage to the motor.
This air conditioner is highly efficient and does not require an electrolytic capacitor on the output side of the rectifier circuit, and thus an increase in the size and cost of the circuit is suppressed.
An air conditioner according to a sixth aspect is the air conditioner according to the first aspect, in which the power conversion device is a matrix converter that directly converts an AC voltage of the AC power source into an AC voltage having a predetermined frequency and supplies the AC voltage having the predetermined frequency to the motor.
This air conditioner is highly efficient and does not require an electrolytic capacitor on the output side of the rectifier circuit, and thus an increase in the size and cost of the circuit is suppressed.
An air conditioner according to a seventh aspect is the air conditioner according to the first aspect, in which the compressor is any one of a scroll compressor, a rotary compressor, a turbo compressor, and a screw compressor.
An air conditioner according to an eighth aspect is the air conditioner according to any one of the first aspect to the seventh aspect, in which the motor is a permanent magnet synchronous motor having a rotor including a permanent magnet.
An air conditioner according to a ninth aspect is the air conditioner according to any of the first through eighth aspects, wherein the refrigerant comprises trans-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (R32), and 2,3,3,3-tetrafluoro-1-propene (R1234yf),
wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum in the refrigerant is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments IJ, JN, NE, and EI that connect the following 4 points:
point I (72.0, 0.0, 28.0),
point J (48.5, 18.3, 33.2),
point N (27.7, 18.2, 54.1), and
point E (58.3, 0.0, 41.7),
or on these line segments (excluding the points on the line segment EI;
the line segment IJ is represented by coordinates (0.0236y2−1.7616y+72.0, y, −0.0236y2+0.7616y+28.0);
the line segment NE is represented by coordinates (0.012y2−1.9003y+58.3, y, −0.012y2+0.9003y+41.7); and
the line segments JN and EI are straight lines.
In this air conditioner, the motor rotation rate of the compressor can be changed in accordance with an air conditioning load, and thus a high annual performance factor (AFP) can also be achieved when a refrigerant having a sufficiently low GWP, a refrigeration capacity (may also be referred to as a cooling capacity or a capacity) equal to those of R410A and classified with lower flammability (Class 2L) in the standard of The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) is used.
An air conditioner according to a tenth aspect is the air conditioner according to any of the first through eighth aspects, wherein the refrigerant comprises HFO-1132(E), R32, and R1234yf,
wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum in the refrigerant is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments MM′, M′N, NV, VG, and GM that connect the following 5 points:
point M (52.6, 0.0, 47.4),
point M′ (39.2, 5.0, 55.8),
point N (27.7, 18.2, 54.1),
point V (11.0, 18.1, 70.9), and
point G (39.6, 0.0, 60.4),
or on these line segments (excluding the points on the line segment GM);
the line segment MM′ is represented by coordinates (0.132y2−3.34y+52.6, y, −0.132y2+2.34y+47.4);
the line segment M′N is represented by coordinates (0.0596y2−2.2541y+48.98, y, −0.0596y2+1.2541y+51.02);
the line segment VG is represented by coordinates (0.0123y2−1.8033y+39.6, y, −0.0123y2+0.8033y+60.4); and
the line segments NV and GM are straight lines.
In this air conditioner, the motor rotation rate of the compressor can be changed in accordance with an air conditioning load, and thus a high annual performance factor (AFP) can also be achieved when a refrigerant having a sufficiently low GWP, a refrigeration capacity (may also be referred to as a cooling capacity or a capacity) equal to those of R410A and classified with lower flammability (Class 2L) in the standard of The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) is used.
An air conditioner according to a eleventh aspect is the air conditioner according to any of the first through eighth aspects, wherein the refrigerant comprises HFO-1132(E), R32, and R1234yf,
wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum in the refrigerant is respectively represented by x, y and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments ON, NU, and UO that connect the following 3 points:
point O (22.6, 36.8, 40.6),
point N (27.7, 18.2, 54.1), and
point U (3.9, 36.7, 59.4),
or on these line segments;
the line segment ON is represented by coordinates (0.0072y2−0.6701y+37.512, y, −0.0072y2−0.3299y+62.488);
the line segment NU is represented by coordinates (0.0083y2−1.7403y+56.635, y, −0.0083y2+0.7403y+43.365); and
the line segment UO is a straight line.
In this air conditioner, the motor rotation rate of the compressor can be changed in accordance with an air conditioning load, and thus a high annual performance factor (AFP) can also be achieved when a refrigerant having a sufficiently low GWP, a refrigeration capacity (may also be referred to as a cooling capacity or a capacity) equal to those of R410A and classified with lower flammability (Class 2L) in the standard of The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) is used.
An air conditioner according to a twelfth aspect is the air conditioner according to any of the first through eighth aspects, wherein the refrigerant comprises HFO-1132(E), R32, and R1234yf,
wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum in the refrigerant is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments QR, RT, TL, LK, and KQ that connect the following 5 points:
point Q (44.6, 23.0, 32.4),
point R (25.5, 36.8, 37.7),
point T (8.6, 51.6, 39.8),
point L (28.9, 51.7, 19.4), and
point K (35.6, 36.8, 27.6),
or on these line segments;
the line segment QR is represented by coordinates (0.0099y2−1.975y+84.765, y, −0.0099y2+0.975y+15.235);
the line segment RT is represented by coordinates (0.0082y2−1.8683y+83.126, y, −0.0082y2+0.8683y+16.874);
the line segment LK is represented by coordinates (0.0049y2−0.8842y+61.488, y, −0.0049y2−0.1158y+38.512);
the line segment KQ is represented by coordinates (0.0095y2−1.2222y+67.676, y, −0.0095y2+0.2222y+32.324); and
the line segment TL is a straight line.
In this air conditioner, the motor rotation rate of the compressor can be changed in accordance with an air conditioning load, and thus a high annual performance factor (AFP) can also be achieved when a refrigerant having a sufficiently low GWP, a refrigeration capacity (may also be referred to as a cooling capacity or a capacity) equal to those of R410A and classified with lower flammability (Class 2L) in the standard of The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) is used.
An air conditioner according to a thirteenth aspect is the air conditioner according to any of the first through eighth aspects, wherein the refrigerant comprises HFO-1132(E), R32, and R1234yf,
wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum in the refrigerant is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments PS, ST, and TP that connect the following 3 points:
point P (20.5, 51.7, 27.8),
point S (21.9, 39.7, 38.4), and
point T (8.6, 51.6, 39.8),
or on these line segments;
the line segment PS is represented by coordinates (0.0064y2−0.7103y+40.1, y, −0.0064y2−0.2897y+59.9);
the line segment ST is represented by coordinates (0.0082y2−1.8683y+83.126, y, −0.0082y2+0.8683y+16.874); and
the line segment TP is a straight line.
In this air conditioner, the motor rotation rate of the compressor can be changed in accordance with an air conditioning load, and thus a high annual performance factor (AFP) can also be achieved when a refrigerant having a sufficiently low GWP, a refrigeration capacity (may also be referred to as a cooling capacity or a capacity) equal to those of R410A and classified with lower flammability (Class 2L) in the standard of The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) is used.
In the present specification, the term “refrigerant” includes at least compounds that are specified in ISO 817 (International Organization for Standardization), and that are given a refrigerant number (ASHRAE number) representing the type of refrigerant with “R” at the beginning; and further includes refrigerants that have properties equivalent to those of such refrigerants, even though a refrigerant number is not yet given. Refrigerants are broadly divided into fluorocarbon compounds and non-fluorocarbon compounds in terms of the structure of the compounds. Fluorocarbon compounds include chlorofluorocarbons (CFC), hydrochlorofluorocarbons (HCFC), and hydrofluorocarbons (HFC). Non-fluorocarbon compounds include propane (R290), propylene (R1270), butane (R600), isobutane (R600a), carbon dioxide (R744), ammonia (R717), and the like.
In the present specification, the phrase “composition comprising a refrigerant” at least includes (1) a refrigerant itself (including a mixture of refrigerants), (2) a composition that further comprises other components and that can be mixed with at least a refrigeration oil to obtain a working fluid for a refrigerating machine, and (3) a working fluid for a refrigerating machine containing a refrigeration oil. In the present specification, of these three embodiments, the composition (2) is referred to as a “refrigerant composition” so as to distinguish it from a refrigerant itself (including a mixture of refrigerants). Further, the working fluid for a refrigerating machine (3) is referred to as a “refrigeration oil-containing working fluid” so as to distinguish it from the “refrigerant composition.”
In the present specification, when the term “alternative” is used in a context in which the first refrigerant is replaced with the second refrigerant, the first type of “alternative” means that equipment designed for operation using the first refrigerant can be operated using the second refrigerant under optimum conditions, optionally with changes of only a few parts (at least one of the following: refrigeration oil, gasket, packing, expansion valve, dryer, and other parts) and equipment adjustment. In other words, this type of alternative means that the same equipment is operated with an alternative refrigerant. Embodiments of this type of “alternative” include “drop-in alternative,” “nearly drop-in alternative,” and “retrofit,” in the order in which the extent of changes and adjustment necessary for replacing the first refrigerant with the second refrigerant is smaller.
The term “alternative” also includes a second type of “alternative,” which means that equipment designed for operation using the second refrigerant is operated for the same use as the existing use with the first refrigerant by using the second refrigerant. This type of alternative means that the same use is achieved with an alternative refrigerant.
In the present specification, the term “refrigerating machine” refers to machines in general that draw heat from an object or space to make its temperature lower than the temperature of ambient air, and maintain a low temperature. In other words, refrigerating machines refer to conversion machines that gain energy from the outside to do work, and that perform energy conversion, in order to transfer heat from where the temperature is lower to where the temperature is higher.
In the present specification, a refrigerant having a “WCF lower flammability” means that the most flammable composition (worst case of formulation for flammability: WCF) has a burning velocity of 10 cm/s or less according to the US ANSI/ASHRAE Standard 34-2013. Further, in the present specification, a refrigerant having “ASHRAE lower flammability” means that the burning velocity of WCF is 10 cm/s or less, that the most flammable fraction composition (worst case of fractionation for flammability: WCFF), which is specified by performing a leakage test during storage, shipping, or use based on ANSI/ASHRAE 34-2013 using WCF, has a burning velocity of 10 cm/s or less, and that flammability classification according to the US ANSI/ASHRAE Standard 34-2013 is determined to classified as be “Class 2L.”
In the present specification, a refrigerant having an “RCL of x % or more” means that the refrigerant has a refrigerant concentration limit (RCL), calculated in accordance with the US ANSI/ASHRAE Standard 34-2013, of x % or more. RCL refers to a concentration limit in the air in consideration of safety factors. RCL is an index for reducing the risk of acute toxicity, suffocation, and flammability in a closed space where humans are present. RCL is determined in accordance with the ASHRAE Standard. More specifically, RCL is the lowest concentration among the acute toxicity exposure limit (ATEL), the oxygen deprivation limit (ODL), and the flammable concentration limit (FCL), which are respectively calculated in accordance with sections 7.1.1, 7.1.2, and 7.1.3 of the ASHRAE Standard.
In the present specification, temperature glide refers to an absolute value of the difference between the initial temperature and the end temperature in the phase change process of a composition containing the refrigerant of the present disclosure in the heat exchanger of a refrigerant system.
Any one of various refrigerants, such as refrigerant D, details of these refrigerant are to be mentioned later, can be used as the refrigerant.
The refrigerant according to the present disclosure can be preferably used as a working fluid in a refrigerating machine.
The composition according to the present disclosure is suitable for use as an alternative refrigerant for HFC refrigerant such as R410A, R407C and R404 etc, or HCFC refrigerant such as R22 etc.
The refrigerant composition according to the present disclosure comprises at least the refrigerant according to the present disclosure, and can be used for the same use as the refrigerant according to the present disclosure. Moreover, the refrigerant composition according to the present disclosure can be further mixed with at least a refrigeration oil to thereby obtain a working fluid for a refrigerating machine.
The refrigerant composition according to the present disclosure further comprises at least one other component in addition to the refrigerant according to the present disclosure. The refrigerant composition according to the present disclosure may comprise at least one of the following other components, if necessary. As described above, when the refrigerant composition according to the present disclosure is used as a working fluid in a refrigerating machine, it is generally used as a mixture with at least a refrigeration oil. Therefore, it is preferable that the refrigerant composition according to the present disclosure does not substantially comprise a refrigeration oil. Specifically, in the refrigerant composition according to the present disclosure, the content of the refrigeration oil based on the entire refrigerant composition is preferably 0 to 1 mass %, and more preferably 0 to 0.1 mass %.
The refrigerant composition according to the present disclosure may contain a small amount of water. The water content of the refrigerant composition is preferably 0.1 mass % or less based on the entire refrigerant. A small amount of water contained in the refrigerant composition stabilizes double bonds in the molecules of unsaturated fluorocarbon compounds that can be present in the refrigerant, and makes it less likely that the unsaturated fluorocarbon compounds will be oxidized, thus increasing the stability of the refrigerant composition.
A tracer is added to the refrigerant composition according to the present disclosure at a detectable concentration such that when the refrigerant composition has been diluted, contaminated, or undergone other changes, the tracer can trace the changes.
The refrigerant composition according to the present disclosure may comprise a single tracer, or two or more tracers.
The tracer is not limited, and can be suitably selected from commonly used tracers. Preferably, a compound that cannot be an impurity inevitably mixed in the refrigerant of the present disclosure is selected as the tracer.
Examples of tracers include hydrofluorocarbons, hydrochlorofluorocarbons, chlorofluorocarbons, hydrochlorocarbons, fluorocarbons, deuterated hydrocarbons, deuterated hydrofluorocarbons, perfluorocarbons, fluoroethers, brominated compounds, iodinated compounds, alcohols, aldehydes, ketones, and nitrous oxide (N2O). The tracer is particularly preferably a hydrofluorocarbon, a hydrochlorofluorocarbon, a chlorofluorocarbon, a fluorocarbon, a hydrochlorocarbon, a fluorocarbon, or a fluoroether.
The following compounds are preferable as the tracer.
FC-14 (tetrafluoromethane, CF4)
HCC-40 (chloromethane, CH3Cl)
HFC-23 (trifluoromethane, CHF3)
HFC-41 (fluoromethane, CH3Cl)
HFC-125 (pentafluoroethane, CF3CHF2)
HFC-134a (1,1,1,2-tetrafluoroethane, CF3CH2F)
HFC-134 (1,1,2,2-tetrafluoroethane, CHF2CHF2)
HFC-143a (1,1,1-trifluoroethane, CF3CH3)
HFC-143 (1,1,2-trifluoroethane, CHF2CH2F)
HFC-152a (1,1-difluoroethane, CHF2CH3)
HFC-152 (1,2-difluoroethane, CH2FCH2F)
HFC-161 (fluoroethane, CH3CH2F)
HFC-245fa (1,1,1,3,3-pentafluoropropane, CF3CH2CHF2)
HFC-236fa (1,1,1,3,3,3-hexafluoropropane, CF3CH2CF3)
HFC-236ea (1,1,1,2,3,3-hexafluoropropane, CF3CHFCHF2)
HFC-227ea (1,1,1,2,3,3,3-heptafluoropropane, CF3CHFCF3)
HCFC-22 (chlorodifluoromethane, CHClF2)
HCFC-31 (chlorofluoromethane, CH2ClF)
CFC-1113 (chlorotrifluoroethylene, CF2═CClF)
HFE-125 (trifluoromethyl-difluoromethyl ether, CF3OCHF2)
HFE-134a (trifluoromethyl-fluoromethyl ether, CF3OCH2F)
HFE-143a (trifluoromethyl-methyl ether, CF3OCH3)
HFE-227ea (trifluoromethyl-tetrafluoroethyl ether, CF3OCHFCF3)
HFE-236fa (trifluoromethyl-trifluoroethyl ether, CF3OCH2CF3)
The tracer compound may be present in the refrigerant composition at a total concentration of about 10 parts per million (ppm) to about 1000 ppm. Preferably, the tracer compound is present in the refrigerant composition at a total concentration of about 30 ppm to about 500 ppm, and most preferably, the tracer compound is present at a total concentration of about 50 ppm to about 300 ppm.
The refrigerant composition according to the present disclosure may comprise a single ultraviolet fluorescent dye, or two or more ultraviolet fluorescent dyes.
The ultraviolet fluorescent dye is not limited, and can be suitably selected from commonly used ultraviolet fluorescent dyes.
Examples of ultraviolet fluorescent dyes include naphthalimide, coumarin, anthracene, phenanthrene, xanthene, thioxanthene, naphthoxanthene, fluorescein, and derivatives thereof. The ultraviolet fluorescent dye is particularly preferably either naphthalimide or coumarin, or both.
The refrigerant composition according to the present disclosure may comprise a single stabilizer, or two or more stabilizers.
The stabilizer is not limited, and can be suitably selected from commonly used stabilizers.
Examples of stabilizers include nitro compounds, ethers, and amines.
Examples of nitro compounds include aliphatic nitro compounds, such as nitromethane and nitroethane; and aromatic nitro compounds, such as nitro benzene and nitro styrene.
Examples of ethers include 1,4-dioxane.
Examples of amines include 2,2,3,3,3-pentafluoropropylamine and diphenylamine.
Examples of stabilizers also include butylhydroxyxylene and benzotriazole.
The content of the stabilizer is not limited. Generally, the content of the stabilizer is preferably 0.01 to 5 mass %, and more preferably 0.05 to 2 mass %, based on the entire refrigerant.
The refrigerant composition according to the present disclosure may comprise a single polymerization inhibitor, or two or more polymerization inhibitors.
The polymerization inhibitor is not limited, and can be suitably selected from commonly used polymerization inhibitors.
Examples of polymerization inhibitors include 4-methoxy-1-naphthol, hydroquinone, hydroquinone methyl ether, dimethyl-t-butylphenol, 2,6-di-tert-butyl-p-cresol, and benzotriazole.
The content of the polymerization inhibitor is not limited. Generally, the content of the polymerization inhibitor is preferably 0.01 to 5 mass %, and more preferably 0.05 to 2 mass %, based on the entire refrigerant.
The refrigeration oil-containing working fluid according to the present disclosure comprises at least the refrigerant or refrigerant composition according to the present disclosure and a refrigeration oil, for use as a working fluid in a refrigerating machine. Specifically, the refrigeration oil-containing working fluid according to the present disclosure is obtained by mixing a refrigeration oil used in a compressor of a refrigerating machine with the refrigerant or the refrigerant composition. The refrigeration oil-containing working fluid generally comprises 10 to 50 mass % of refrigeration oil.
The refrigeration oil is not limited, and can be suitably selected from commonly used refrigeration oils. In this case, refrigeration oils that are superior in the action of increasing the miscibility with the mixture and the stability of the mixture, for example, are suitably selected as necessary.
The base oil of the refrigeration oil is preferably, for example, at least one member selected from the group consisting of polyalkylene glycols (PAG), polyol esters (POE), and polyvinyl ethers (PVE).
The refrigeration oil may further contain additives in addition to the base oil. The additive may be at least one member selected from the group consisting of antioxidants, extreme-pressure agents, acid scavengers, oxygen scavengers, copper deactivators, rust inhibitors, oil agents, and antifoaming agents.
A refrigeration oil with a kinematic viscosity of 5 to 400 cSt at 40° C. is preferable from the standpoint of lubrication.
The refrigeration oil-containing working fluid according to the present disclosure may further optionally contain at least one additive. Examples of additives include compatibilizing agents described below.
The refrigeration oil-containing working fluid according to the present disclosure may comprise a single compatibilizing agent, or two or more compatibilizing agents.
The compatibilizing agent is not limited, and can be suitably selected from commonly used compatibilizing agents.
Examples of compatibilizing agents include polyoxyalkylene glycol ethers, amides, nitriles, ketones, chlorocarbons, esters, lactones, aryl ethers, fluoroethers, and 1,1,1-trifluoroalkanes. The compatibilizing agent is particularly preferably a polyoxyalkylene glycol ether.
Hereinafter, the refrigerants which are the refrigerants used in the present embodiment, will be described in detail.
The refrigerant D according to the present disclosure is a mixed refrigerant comprising trans-1,2-difluoroethylene (HFO-1132(E)), difluoromethane (R32), and 2,3,3,3-tetrafluoro-1-propene (R1234yf).
The refrigerant D according to the present disclosure has various properties that are desirable as an R410A-alternative refrigerant; i.e., a refrigerating capacity equivalent to that of R410A, a sufficiently low GWP, and a lower flammability (Class 2L) according to the ASHRAE standard.
The refrigerant D according to the present disclosure is preferably a refrigerant wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments IJ, JN, NE, and EI that connect the following 4 points:
point I (72.0, 0.0, 28.0),
point J (48.5, 18.3, 33.2),
point N (27.7, 18.2, 54.1), and
point E (58.3, 0.0, 41.7),
or on these line segments (excluding the points on the line segment EI);
the line segment IJ is represented by coordinates (0.0236y2−1.7616y+72.0, y, −0.0236y2+0.7616y+28.0);
the line segment NE is represented by coordinates (0.012y2−1.9003y+58.3, y, −0.012y2+0.9003y+41.7); and
the line segments JN and EI are straight lines. When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 80% or more relative to R410A, a GWP of 125 or less, and a WCF lower flammability.
The refrigerant D according to the present disclosure is preferably a refrigerant wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments MM′, M′N, NV, VG, and GM that connect the following 5 points:
point M (52.6, 0.0, 47.4),
point M′ (39.2, 5.0, 55.8),
point N (27.7, 18.2, 54.1),
point V (11.0, 18.1, 70.9), and
point G (39.6, 0.0, 60.4),
or on these line segments (excluding the points on the line segment GM);
the line segment MM′ is represented by coordinates (0.132y2−3.34y+52.6, y, −0.132y2+2.34y+47.4);
the line segment M′N is represented by coordinates (0.0596y2−2.2541y+48.98, y, −0.0596y2+1.2541y+51.02);
the line segment VG is represented by coordinates (0.0123y2−1.8033y+39.6, y, −0.0123y2+0.8033y+60.4); and
the line segments NV and GM are straight lines. When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 70% or more relative to R410A, a GWP of 125 or less, and an ASHRAE lower flammability.
The refrigerant D according to the present disclosure is preferably a refrigerant wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments ON, NU, and UO that connect the following 3 points:
point O (22.6, 36.8, 40.6),
point N (27.7, 18.2, 54.1), and
point U (3.9, 36.7, 59.4),
or on these line segments;
the line segment ON is represented by coordinates (0.0072y2−0.6701y+37.512, y, −0.0072y2−0.3299y+62.488);
the line segment NU is represented by coordinates (0.0083y2−1.7403y+56.635, y, −0.0083y2+0.7403y+43.365); and
the line segment UO is a straight line. When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 80% or more relative to R410A, a GWP of 250 or less, and an ASHRAE lower flammability.
The refrigerant D according to the present disclosure is preferably a refrigerant wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments QR, RT, TL, LK, and KQ that connect the following 5 points:
point Q (44.6, 23.0, 32.4),
point R (25.5, 36.8, 37.7),
point T (8.6, 51.6, 39.8),
point L (28.9, 51.7, 19.4), and
point K (35.6, 36.8, 27.6),
or on these line segments;
the line segment QR is represented by coordinates (0.0099y2−1.975y+84.765, y, −0.0099y2+0.975y+15.235);
the line segment RT is represented by coordinates (0.0082y2−1.8683y+83.126, y, −0.0082y2+0.8683y+16.874);
the line segment LK is represented by coordinates (0.0049y2−0.8842y+61.488, y, −0.0049y2−0.1158y+38.512);
the line segment KQ is represented by coordinates (0.0095y2−1.2222y+67.676, y, −0.0095y2+0.2222y+32.324); and
the line segment TL is a straight line. When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 92.5% or more relative to R410A, a GWP of 350 or less, and a WCF lower flammability.
The refrigerant D according to the present disclosure is preferably a refrigerant wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments PS, ST, and TP that connect the following 3 points:
point P (20.5, 51.7, 27.8),
point S (21.9, 39.7, 38.4), and
point T (8.6, 51.6, 39.8),
or on these line segments;
the line segment PS is represented by coordinates (0.0064y2−0.7103y+40.1, y, −0.0064y2−0.2897y+59.9);
the line segment ST is represented by coordinates (0.0082y2−1.8683y+83.126, y, −0.0082y2+0.8683y+16.874); and
the line segment TP is a straight line. When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 92.5% or more relative to R410A, a GWP of 350 or less, and an ASHRAE lower flammability.
The refrigerant D according to the present disclosure is preferably a refrigerant wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments ac, cf, fd, and da that connect the following 4 points:
point a (71.1, 0.0, 28.9),
point c (36.5, 18.2, 45.3),
point f (47.6, 18.3, 34.1), and
point d (72.0, 0.0, 28.0),
or on these line segments;
the line segment ac is represented by coordinates (0.0181y2−2.2288y+71.096, y, −0.0181y2+1.2288y+28.904);
the line segment fd is represented by coordinates (0.02y2−1.7y+72, y, −0.02y2+0.7y+28); and
the line segments cf and da are straight lines. When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 85% or more relative to R410A, a GWP of 125 or less, and a lower flammability (Class 2L) according to the ASHRAE standard.
The refrigerant D according to the present disclosure is preferably a refrigerant wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments ab, be, ed, and da that connect the following 4 points:
point a (71.1, 0.0, 28.9),
point b (42.6, 14.5, 42.9),
point e (51.4, 14.6, 34.0), and
point d (72.0, 0.0, 28.0),
or on these line segments;
the line segment ab is represented by coordinates (0.0181y2−2.2288y+71.096, y, −0.0181y2+1.2288y+28.904);
the line segment ed is represented by coordinates (0.02y2−1.7y+72, y, −0.02y2+0.7y+28); and
the line segments be and da are straight lines. When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 85% or more relative to R410A, a GWP of 100 or less, and a lower flammability (Class 2L) according to the ASHRAE standard.
The refrigerant D according to the present disclosure is preferably a refrigerant wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments gi, ij, and jg that connect the following 3 points:
point g (77.5, 6.9, 15.6),
point i (55.1, 18.3, 26.6), and
point j (77.5. 18.4, 4.1),
or on these line segments;
the line segment gi is represented by coordinates (0.02y2−2.4583y+93.396, y, −0.02y2+1.4583y+6.604); and
the line segments ij and jg are straight lines. When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 95% or more relative to R410A and a GWP of 100 or less, undergoes fewer or no changes such as polymerization or decomposition, and also has excellent stability.
The refrigerant D according to the present disclosure is preferably a refrigerant wherein
when the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments gh, hk, and kg that connect the following 3 points:
point g (77.5, 6.9, 15.6),
point h (61.8, 14.6, 23.6), and
point k (77.5, 14.6, 7.9),
or on these line segments;
the line segment gh is represented by coordinates (0.02y2−2.4583y+93.396, y, −0.02y2+1.4583y+6.604); and
the line segments hk and kg are straight lines. When the requirements above are satisfied, the refrigerant according to the present disclosure has a refrigerating capacity ratio of 95% or more relative to R410A and a GWP of 100 or less, undergoes fewer or no changes such as polymerization or decomposition, and also has excellent stability.
The refrigerant D according to the present disclosure may further comprise other additional refrigerants in addition to HFO-1132(E), R32, and R1234yf, as long as the above properties and effects are not impaired. In this respect, the refrigerant according to the present disclosure preferably comprises HFO-1132(E), R32, and R1234yf in a total amount of 99.5 mass % or more, more preferably 99.75 mass % or more, and still more preferably 99.9 mass % or more based on the entire refrigerant.
Such additional refrigerants are not limited, and can be selected from a wide range of refrigerants. The mixed refrigerant may comprise a single additional refrigerant, or two or more additional refrigerants.
The present disclosure is described in more detail below with reference to Examples of refrigerant D. However, the refrigerant D is not limited to the Examples.
The composition of each mixed refrigerant of HFO-1132(E), R32, and R1234yf was defined as WCF. A leak simulation was performed using the NIST Standard Reference Database REFLEAK Version 4.0 under the conditions of Equipment, Storage, Shipping, Leak, and Recharge according to the ASHRAE Standard 34-2013. The most flammable fraction was defined as WCFF.
A burning velocity test was performed using the apparatus shown in
The results indicate that under the condition that the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, when coordinates (x,y,z) in the ternary composition diagram shown in
The results also indicate that when coordinates (x,y,z) in the ternary composition diagram shown in
Mixed refrigerants were prepared by mixing HFO-1132(E), R32, and R1234yf in amounts (mass %) shown in Tables 4 to 32 based on the sum of HFO-1132(E), R32, and R1234yf. The coefficient of performance (COP) ratio and the refrigerating capacity ratio relative to R410 of the mixed refrigerants shown in Tables 116 to 144 were determined. The conditions for calculation were as described below.
Evaporating temperature: 5° C.
Condensation temperature: 45° C.
Degree of superheating: 5 K
Degree of subcooling: 5 K
Compressor efficiency: 70%
Tables 4 to 32 show these values together with the GWP of each mixed refrigerant.
The results also indicate that under the condition that the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, when coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments IJ, JN, NE, and EI that connect the following 4 points:
point I (72.0, 0.0, 28.0),
point J (48.5, 18.3, 33.2),
point N (27.7, 18.2, 54.1), and
point E (58.3, 0.0, 41.7),
or on these line segments (excluding the points on the line segment EI),
the line segment IJ is represented by coordinates (0.0236y2−1.7616y+72.0, y, −0.0236y2+0.7616y+28.0),
the line segment NE is represented by coordinates (0.012y2−1.9003y+58.3, y, −0.012y2+0.9003y+41.7), and
the line segments JN and EI are straight lines, the refrigerant D has a refrigerating capacity ratio of 80% or more relative to R410A, a GWP of 125 or less, and a WCF lower flammability.
The results also indicate that under the condition that the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, when coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments MM′, M′N, NV, VG, and GM that connect the following 5 points:
point M (52.6, 0.0, 47.4),
point M′ (39.2, 5.0, 55.8),
point N (27.7, 18.2, 54.1),
point V (11.0, 18.1, 70.9), and
point G (39.6, 0.0, 60.4),
or on these line segments (excluding the points on the line segment GM),
the line segment MM′ is represented by coordinates (0.132y2−3.34y+52.6, y, −0.132y2+2.34y+47.4),
the line segment M′N is represented by coordinates (0.0596y2−2.2541y+48.98, y, −0.0596y2+1.2541y+51.02),
the line segment VG is represented by coordinates (0.0596y2−2.2541y+48.98, y, −0.0596y2+1.2541y+51.02), and
the line segments NV and GM are straight lines, the refrigerant D according to the present disclosure has a refrigerating capacity ratio of 70% or more relative to R410A, a GWP of 125 or less, and an ASHRAE lower flammability.
The results also indicate that under the condition that the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, when coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments ON, NU, and UO that connect the following 3 points:
point O (22.6, 36.8, 40.6),
point N (27.7, 18.2, 54.1), and
point U (3.9, 36.7, 59.4),
or on these line segments,
the line segment ON is represented by coordinates (0.0072y2−0.6701y+37.512, y, −0.0072y2−0.3299y+62.488),
the line segment NU is represented by coordinates (0.0083y2−1.7403y+56.635, y, −0.0083y2+0.7403y+43.365), and
the line segment UO is a straight line, the refrigerant D according to the present disclosure has a refrigerating capacity ratio of 80% or more relative to R410A, a GWP of 250 or less, and an ASHRAE lower flammability.
The results also indicate that under the condition that the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, when coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments QR, RT, TL, LK, and KQ that connect the following 5 points:
point Q (44.6, 23.0, 32.4),
point R (25.5, 36.8, 37.7),
point T (8.6, 51.6, 39.8),
point L (28.9, 51.7, 19.4), and
point K (35.6, 36.8, 27.6),
or on these line segments,
the line segment QR is represented by coordinates (0.0099y2−1.975y+84.765, y, −0.0099y2+0.975y+15.235),
the line segment RT is represented by coordinates (0.0082y2−1.8683y+83.126, y, −0.0082y2+0.8683y+16.874),
the line segment LK is represented by coordinates (0.0049y2−0.8842y+61.488, y, −0.0049y2−0.1158y+38.512),
the line segment KQ is represented by coordinates (0.0095y2−1.2222y+67.676, y, −0.0095y2+0.2222y+32.324), and
the line segment TL is a straight line, the refrigerant D according to the present disclosure has a refrigerating capacity ratio of 92.5% or more relative to R410A, a GWP of 350 or less, and a WCF lower flammability.
The results further indicate that under the condition that the mass % of HFO-1132(E), R32, and R1234yf based on their sum is respectively represented by x, y, and z, when coordinates (x,y,z) in a ternary composition diagram in which the sum of HFO-1132(E), R32, and R1234yf is 100 mass % are within the range of a figure surrounded by line segments PS, ST, and TP that connect the following 3 points:
point P (20.5, 51.7, 27.8),
point S (21.9, 39.7, 38.4), and
point T (8.6, 51.6, 39.8),
or on these line segments,
the line segment PS is represented by coordinates (0.0064y2−0.7103y+40.1, y, −0.0064y2−0.2897y+59.9),
the line segment ST is represented by coordinates (0.0082y2−1.8683y+83.126, y, −0.0082y2+0.8683y+16.874), and
the line segment TP is a straight line, the refrigerant D according to the present disclosure has a refrigerating capacity ratio of 92.5% or more relative to R410A, a GWP of 350 or less, and an ASHRAE lower flammability.
The air conditioner 1 has a refrigerant circuit 11 in which a compressor 100, a four-way switching valve 16, a heat-source-side heat exchanger 17, an expansion valve 18 serving as a decompression mechanism, and a utilization-side heat exchanger 13 are connected in a loop shape by refrigerant pipes.
In this embodiment, the refrigerant circuit 11 is filled with refrigerant for performing a vapor compression refrigeration cycle. The refrigerant is a refrigerant mixture containing 1,2-difluoroethylene, and any one of the above-described refrigerant A to refrigerant E can be used. The refrigerant circuit 11 is filled with refrigerating machine oil together with the refrigerant mixture.
In the refrigerant circuit 11, the utilization-side heat exchanger 13 belongs to the utilization unit 2. In addition, a utilization-side fan 14 is mounted in the utilization unit 2. The utilization-side fan 14 generates an air flow to the utilization-side heat exchanger 13.
A utilization-side communicator 35 and a utilization-side microcomputer 41 are mounted in the utilization unit 2. The utilization-side communicator 35 is connected to the utilization-side microcomputer 41.
The utilization-side communicator 35 is used by the utilization unit 2 to communicate with the heat source unit 3. The utilization-side microcomputer 41 is supplied with a control voltage even during a standby state in which the air conditioner 1 is not operating. Thus, the utilization-side microcomputer 41 is constantly activated.
In the refrigerant circuit 11, the compressor 100, the four-way switching valve 16, the heat-source-side heat exchanger 17, and the expansion valve 18 belong to the heat source unit 3. In addition, a heat-source-side fan 19 is mounted in the heat source unit 3. The heat-source-side fan 19 generates an air flow to the heat-source-side heat exchanger 17.
In addition, a power conversion device 30, a heat-source-side communicator 36, and a heat-source-side microcomputer 42 are mounted in the heat source unit 3. The power conversion device 30 and the heat-source-side communicator 36 are connected to the heat-source-side microcomputer 42.
The power conversion device 30 is a circuit for driving a motor 70 of the compressor 100. The heat-source-side communicator 36 is used by the heat source unit 3 to communicate with the utilization unit 2. The heat-source-side microcomputer 42 controls the motor 70 of the compressor 100 via the power conversion device 30 and also controls other devices in the heat source unit 3 (for example, the heat-source-side fan 19).
The rotor 71 includes a permanent magnet with a plurality of poles, the N-pole and the S-pole, and rotates about a rotation axis with respect to the stator 72.
The power conversion device 30 is mounted in the heat source unit 3, as illustrated in
The rectifier circuit 21 has a bridge structure made up of four diodes D1a, D1b, D2a, and D2b. Specifically, the diodes D1a and D1b are connected in series to each other, and the diodes D2a and D2b are connected in series to each other. The cathode terminals of the diodes D1a and D2a are connected to a plus-side terminal of the capacitor 22 and function as a positive-side output terminal of the rectifier circuit 21. The anode terminals of the diodes D1b and D2b are connected to a minus-side terminal of the capacitor 22 and function as a negative-side output terminal of the rectifier circuit 21.
A node between the diode D1a and the diode D1b is connected to one pole of an alternating-current (AC) power source 90. A node between the diode D2a and the diode D2b is connected to the other pole of the AC power source 90. The rectifier circuit 21 rectifies an AC voltage output from the AC power source 90 to generate a direct-current (DC) voltage, and supplies the DC voltage to the capacitor 22.
The capacitor 22 has one end connected to the positive-side output terminal of the rectifier circuit 21 and has the other end connected to the negative-side output terminal of the rectifier circuit 21. The capacitor 22 is a small-capacitance capacitor that does not have a large capacitance for smoothing a voltage rectified by the rectifier circuit 21. Hereinafter, a voltage between the terminals of the capacitor 22 will be referred to as a DC bus voltage Vdc for the convenience of description.
The DC bus voltage Vdc is applied to the inverter 25 connected to the output side of the capacitor 22. In other words, the rectifier circuit 21 and the capacitor 22 constitute the power source circuit 20 for the inverter 25.
The capacitor 22 smooths voltage variation caused by switching in the inverter 25. In this embodiment, a film capacitor is adopted as the capacitor 22.
A voltage detector 23 is connected to the output side of the capacitor 22 and is for detecting the value of a voltage across the capacitor 22, that is, the DC bus voltage Vdc. The voltage detector 23 is configured such that, for example, two resistors connected in series to each other are connected in parallel to the capacitor 22 and the DC bus voltage Vdc is divided. A voltage value at a node between the two resistors i s input to the heat-source-side microcomputer 42.
A current detector 24 is connected between the capacitor 22 and the inverter 25 and to the negative-side output terminal side of the capacitor 22. The current detector 24 detects a motor current that flows through the motor 70 after the motor 70 is activated, as a total value of currents of the three phases.
The current detector 24 may be constituted by, for example, an amplifier circuit including a shunt resistor and an operational amplifier that amplifies a voltage across the shunt resistor. The motor current detected by the current detector 24 is input to the heat-source-side microcomputer 42.
In the inverter 25, three pairs of upper and lower arms respectively corresponding to the phase windings Lu, Lv, and Lw of the U-phase, the V-phase, and the W-phase of the motor 70 are connected in parallel to each other and connected to the output side of the capacitor 22.
In
The transistors Q3a and Q3b are connected in series to each other, the transistors Q4a and Q4b are connected in series to each other, and the transistors Q5a and Q5b are connected in series to each other, to constitute respective upper and lower arms and to form nodes NU, NV, and NW, from which output lines extend toward the phase windings Lu, Lv, and Lw of the corresponding phases.
The diodes D3a to D5b are connected in parallel to the respective transistors Q3a to Q5b such that the collector terminal of the transistor is connected to the cathode terminal of the diode and that the emitter terminal of the transistor is connected to the anode terminal of the diode. The transistor and the diode connected in parallel to each other constitute a switching element.
The inverter 25 generates driving voltages SU, SV, and SW for driving the motor 70 in response to ON and OFF of the transistors Q3a to Q5b at the timing when the DC bus voltage Vdc is applied from the capacitor 22 and when an instruction is provided from the gate driving circuit 26. The driving voltages SU, SV, and SW are respectively output from the node NU between the transistors Q3a and Q3b, the node NV between the transistors Q4a and Q4b, and the node NW between the transistors Q5a and Q5b to the phase windings Lu, Lv, and Lw of the motor 70.
The gate driving circuit 26 changes the ON and OFF states of the transistors Q3a to Q5b of the inverter 25 on the basis of instruction voltages from the heat-source-side microcomputer 42. Specifically, the gate driving circuit 26 generates gate control voltages Gu, Gx, Gv, Gy, Gw, and Gz to be applied to the gates of the respective transistors Q3a to Q5b so that the pulsed driving voltages SU, SV, and SW having a duty determined by the heat-source-side microcomputer 42 are output from the inverter 25 to the motor 70. The generated gate control voltages Gu, Gx, Gv, Gy, Gw, and Gz are applied to the gate terminals of the respective transistors Q3a to Q5b.
The heat-source-side microcomputer 42 is connected to the voltage detector 23, the current detector 24, and the gate driving circuit 26. In this embodiment, the heat-source-side microcomputer 42 causes the motor 70 to be driven by using a rotor position sensorless method. The driving method is not limited to the rotor position sensorless method, and a sensor method may be used.
The rotor position sensorless method is a method for performing driving by estimating the position and rotation rate of the rotor, performing PI control on the rotation rate, performing PI control on a motor current, and the like, by using various parameters indicating the characteristics of the motor 70, a detection result of the voltage detector 23 after the motor 70 is activated, a detection result of the current detector 24, and a predetermined formula model about control of the motor 70, and the like. The various parameters indicating the characteristics of the motor 70 include a winding resistance, an inductance component, an induced voltage, and the number of poles of the motor 70 that is used. For details of rotor position sensorless control, see patent literatures (for example, Japanese Unexamined Patent Application Publication No. 2013-17289).
(6-3-1)
In the air conditioner 1 that uses a refrigerant mixture containing at least 1,2-difluoroethylene, the rotation rate of the motor 70 can be changed via the power conversion device 30 as necessary. In other words, the motor rotation rate of the compressor 100 can be changed in accordance with an air conditioning load, and thus a high annual performance factor (APF) can be achieved.
(6-3-2)
An electrolytic capacitor is not required on the output side of the rectifier circuit 21, and thus an increase in the size and cost of the circuit is suppressed.
The rectifier circuit 121 has a bridge structure made up of six diodes D0a, D0b, D1a, D1b, D2a, and D2b. Specifically, the diodes D0a and D0b are connected in series to each other, the diodes D1a and D1b are connected in series to each other, and the diodes D2a and D2b are connected in series to each other.
The cathode terminals of the diodes D0a, D1a, and D2a are connected to the plus-side terminal of the capacitor 22 and function as a positive-side output terminal of the rectifier circuit 121. The anode terminals of the diodes D0b, D1b, and D2b are connected to the minus-side terminal of the capacitor 22 and function as a negative-side output terminal of the rectifier circuit 121.
A node between the diode D0a and the diode D0b is connected to an R-phase output side of the AC power source 190. A node between the diode D1a and the diode D1b is connected to an S-phase output side of the AC power source 190. A node between the diode D2a and the diode D2b is connected to a T-phase output side of the AC power source 190. The rectifier circuit 121 rectifies an AC voltage output from the AC power source 190 to generate a DC voltage, and supplies the DC voltage to the capacitor 22.
Other than that, the configuration is similar to that of the above-described embodiment, and thus the description thereof is omitted.
(6-5-1)
In the air conditioner 1 that uses a refrigerant mixture containing at least 1,2-difluoroethylene, the rotation rate of the motor 70 can be changed via the power conversion device 130 as necessary. In other words, the motor rotation rate of the compressor 100 can be changed in accordance with an air conditioning load, and thus a high annual performance factor (APF) can be achieved.
(6-5-2)
An electrolytic capacitor is not required on the output side of the rectifier circuit 121, and thus an increase in the size and cost of the circuit is suppressed.
In
Here, a description will be given of the converter 27, the gate driving circuit 28, and the reactor 33, and a description of the other components is omitted.
In
The transistors Q1a and Q1b are connected in series to each other to constitute upper and lower arms, and a node formed accordingly is connected to one pole of the AC power source 90. The transistors Q2a and Q2b are connected in series to each other to constitute upper and lower arms, and a node formed accordingly is connected to the other pole of the AC power source 90.
The diodes D1a to D2b are connected in parallel to the respective transistors Q1a to Q2b such that the collector terminal of the transistor is connected to the cathode terminal of the diode and that the emitter terminal of the transistor is connected to the anode terminal of the diode. The transistor and the diode connected in parallel to each other constitute a switching element.
In the converter 27, the transistors Q1a to Q2b are turned ON and OFF at the timing when an instruction is provided from the gate driving circuit 28.
The gate driving circuit 28 changes the ON and OFF states of the transistors Q1a to Q2b of the converter 27 on the basis of instruction voltages from the heat-source-side microcomputer 42. Specifically, the gate driving circuit 28 generates pulsed gate control voltages Pq, Pr, Ps, and Pt having a duty determined by the heat-source-side microcomputer 42 so as to control a current flowing from the AC power source 90 toward the heat source to a predetermined value. The generated gate control voltages Pq, Pr, Ps, and Pt are applied to the gate terminals of the respective transistors Q1a to Q2b.
The reactor 33 is connected in series to the AC power source 90 between the AC power source 90 and the converter 27. Specifically, one end thereof is connected to one pole of the AC power source 90, and the other end thereof is connected to one input terminal of the converter 27.
The heat-source-side microcomputer 42 turns ON/OFF the transistors Q1a and Q1b or the transistors Q2a and Q2b of the upper and lower arms of the converter 27 to short-circuit/open the transistors for a predetermined time, and controls a current to, for example, a substantially sinusoidal state, thereby improving a power factor of power source input and suppressing harmonic components.
In addition, the heat-source-side microcomputer 42 performs cooperative control between the converter and the inverter so as to control a short-circuit period on the basis of a duty ratio of a gate control voltage for controlling the inverter 25.
The air conditioner 1 is highly efficient and does not require an electrolytic capacitor on the output side of the converter 27, and thus an increase in the size and cost of the circuit is suppressed.
The converter 127 includes a plurality of insulated gate bipolar transistors (IGBTs, hereinafter simply referred to as transistors) Q0a, Q0b, Q1a, Q1b, Q2a, and Q2b, and a plurality of diodes D0a, D0b, D1a, D1b, D2a, and D2b.
The transistors Q0a and Q0b are connected in series to each other to constitute upper and lower arms, and a node formed accordingly is connected to the R-phase output side of the AC power source 190. The transistors Q1a and Q1b are connected in series to each other to constitute upper and lower arms, and a node formed accordingly is connected to the S-phase output side of the AC power source 190. The transistors Q2a and Q2b are connected in series to each other to constitute upper and lower arms, and a node formed accordingly is connected to the T-phase output side of the AC power source 190.
The diodes D0a to D2b are connected in parallel to the respective transistors Q0a to Q2b such that the collector terminal of the transistor is connected to the cathode terminal of the diode and that the emitter terminal of the transistor is connected to the anode terminal of the diode. The transistor and the diode connected in parallel to each other constitute a switching element.
In the converter 127, the transistors Q0a to Q2b are turned ON and OFF at the timing when an instruction is provided from the gate driving circuit 128.
The gate driving circuit 128 changes the ON and OFF states of the transistors Q0a to Q2b of the converter 127 on the basis of instruction voltages from the heat-source-side microcomputer 42. Specifically, the gate driving circuit 128 generates pulsed gate control voltages Po, Pp, Pq, Pr, Ps, and Pt having a duty determined by the heat-source-side microcomputer 42 so as to control a current flowing from the AC power source 190 toward the heat source to a predetermined value. The generated gate control voltages Po, Pp, Pq, Pr, Ps, and Pt are applied to the gate terminals of the respective transistors Q0a to Q2b.
The air conditioner 1 is highly efficient and does not require an electrolytic capacitor on the output side of the converter 127, and thus an increase in the size and cost of the circuit is suppressed.
In
The matrix converter 29 is configured by connecting bidirectional switches S1a, S2a, and S3a to one end of input from the AC power source 90 and connecting bidirectional switches S1b, S2b, and S3b to the other end.
An intermediate terminal between the bidirectional switch S1a and the bidirectional switch S1b connected in series to each other is connected to one end of the U-phase winding Lu among the three-phase windings of the motor 70. An intermediate terminal between the bidirectional switch S2a and the bidirectional switch S2b connected in series to each other is connected to one end of the V-phase winding Lv among the three-phase windings of the motor 70. An intermediate terminal between the bidirectional switch S3 and the bidirectional switch S3b connected in series to each other is connected to one end of the W-phase winding Lw among the three-phase windings of the motor 70.
AC power input from the AC power source 90 is switched by the bidirectional switches S1a to S3b and is converted into AC having a predetermined frequency, thereby being capable of driving the motor 70.
The transistor Q61 has an emitter E connected to the terminal Ta, and a collector C connected to the terminal Tb via the diode D61. The collector C is connected to the cathode of the diode D61.
The transistor Q62 has an emitter E connected to the terminal Tb, and a collector C connected to the terminal Ta via the diode D62. The collector C is connected to the cathode of the diode D62. The terminal Ta is connected to an input side, and the terminal Tb is connected to an output side.
Turning ON of the transistor Q61 and turning OFF of the transistor Q62 enables a current to flow from the terminal Tb to the terminal Ta via the diode D61 and the transistor Q61 in this order. At this time, a flow of a current from the terminal Ta to the terminal Tb (backflow) is prevented by the diode D61.
On the other hand, turning OFF of the transistor Q61 and turning ON of the transistor Q62 enables a current to flow from the terminal Ta to the terminal Tb via the diode D62 and the transistor Q62 in this order. At this time, a flow of a current from the terminal Tb to the terminal Ta (backflow) is prevented by the diode D62.
The air conditioner 1 is highly efficient and does not require an electrolytic capacitor on the output side of the matrix converter 29, and thus an increase in the size and cost of the circuit is suppressed.
It is also a difference that a gate driving circuit 131 is adopted instead of a gate driving circuit 31 in accordance with the change from the matrix converter 29 for a single phase to the matrix converter 129 for three phases. Furthermore, reactors L1, L2, and L3 are connected between the matrix converter 129 and the output sides of the respective phases.
Predetermined three-phase AC voltages obtained through conversion by bidirectional switches S1a to S3c are supplied to the motor 70 via the phase winding terminals TU, TV, and TW. The reactors L1, L2, and L3 are connected to respective input terminals of matrix converter 129. Capacitors C1, C2, and C3 are connected to each other at one ends thereof, and the other ends thereof are connected to output terminals of matrix converter 129.
In the power conversion device 130C, the reactors L1, L2, and L3 are short-circuited via the matrix converter 129, and thereby the energy supplied from the three-phase AC power source 190 can be accumulated in the reactors L1, L2, and L3 and the voltages across the capacitors C1, C2, and C3 can be increased. Accordingly, a voltage utilization rate of 1 or more can be achieved.
At this time, voltage-type three-phase AC voltages Vr, Vs, and Vt are input to the input terminals of the matrix converter 129, and current-type three-phase AC voltages Vu, Vv, and Vw are output from the output terminals.
In addition, the capacitors C1, C2, and C3 constitute LC filters with the reactors L1, L2, and L3, respectively. Thus, high-frequency components included in voltages output to the output terminals can be reduced, and torque pulsation components and noise generated in the motor 70 can be reduced.
Furthermore, compared with an AC-AC conversion circuit including a rectifier circuit and an inverter, the number of switching elements is smaller, and the loss that occurs in the power conversion device 130C can be reduced.
In the power conversion device 130, a clamp circuit 133 is connected between the input terminals and the output terminals. Thus, a surge voltage generated between the input terminals and the output terminals of the matrix converter 129 through switching of the bidirectional switches S1a to S3c can be absorbed by a capacitor in the clamp circuit 133 (see
The anode of the diode D31a and the cathode of the diode D31b are connected to the terminal 135. The anode of the diode D32a and the cathode of the diode D32b are connected to the terminal 136. The anode of the diode D33a and the cathode of the diode D33b are connected to the terminal 137.
The cathodes of the diodes D31a, D32a, and D33a are connected to one end of the capacitor C37. The anodes of the diodes D31b, D32b, and D33b are connected to the other end of the capacitor C37.
The anode of the diode D34a and the cathode of the diode D34b are connected to the terminal 138. The anode of the diode D35a and the cathode of the diode D35b are connected to the terminal 139. The anode of the diode D36a and the cathode of the diode D36b are connected to the terminal 140.
The cathodes of the diodes D34a, D35a, and D36a are connected to the one end of the capacitor C37. The anodes of the diodes D34b, D35b, and D36b are connected to the other end of the capacitor C37.
The terminals 135, 136, and 137 are connected to the input side of the matrix converter 129, and the terminals 138, 139, and 140 are connected to the output side of the matrix converter 129. Because the clamp circuit 133 is connected between the input terminals and the output terminals, a surge voltage generated between the input terminals and the output terminals of the matrix converter 129 through switching of the bidirectional switches S1a to S3b can be absorbed by the capacitor C37 in the clamp circuit 133.
As described above, the power conversion device 130C is capable of supplying a voltage larger than a power source voltage to the motor 70. Thus, even if the current flowing through the power conversion device 130C and the motor 70 is small, a predetermined motor output can be obtained, in other words, only a small current is used. Accordingly, the loss that occurs in the power conversion device 130C and the motor 70 can be reduced.
The air conditioner 1 is highly efficient and does not require an electrolytic capacitor on the output side of the matrix converter 129, and thus an increase in the size and cost of the circuit is suppressed.
(9-1)
As the compressor 100 of the air conditioner 1, any one of a scroll compressor, a rotary compressor, a turbo compressor, and a screw compressor is adopted.
(9-2)
The motor 70 of the compressor 100 is a permanent magnet synchronous motor having the rotor 71 including a permanent magnet.
Embodiments of the present disclosure have been described above. It is to be understood that various changes of the embodiments and details are possible without deviating from the gist and scope of the present disclosure described in the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2017-242183 | Dec 2017 | JP | national |
| 2017-242185 | Dec 2017 | JP | national |
| 2017-242186 | Dec 2017 | JP | national |
| 2017-242187 | Dec 2017 | JP | national |
| PCT/JP2018/037483 | Oct 2018 | JP | national |
| PCT/JP2018/038746 | Oct 2018 | JP | national |
| PCT/JP2018/038747 | Oct 2018 | JP | national |
| PCT/JP2018/038748 | Oct 2018 | JP | national |
| PCT/JP2018/038749 | Oct 2018 | JP | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16913415 | Jun 2020 | US |
| Child | 17892759 | US | |
| Parent | 16772953 | Jun 2020 | US |
| Child | 16913415 | US |
