AU2016213701A1 - Refrigeration / air-conditioning device - Google Patents
Refrigeration / air-conditioning device Download PDFInfo
- Publication number
- AU2016213701A1 AU2016213701A1 AU2016213701A AU2016213701A AU2016213701A1 AU 2016213701 A1 AU2016213701 A1 AU 2016213701A1 AU 2016213701 A AU2016213701 A AU 2016213701A AU 2016213701 A AU2016213701 A AU 2016213701A AU 2016213701 A1 AU2016213701 A1 AU 2016213701A1
- Authority
- AU
- Australia
- Prior art keywords
- discharge
- expansion valve
- discharge temperature
- temperature
- target
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2600/00—Control issues
- F25B2600/25—Control of valves
- F25B2600/2513—Expansion valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/21—Temperatures
- F25B2700/2115—Temperatures of a compressor or the drive means therefor
- F25B2700/21151—Temperatures of a compressor or the drive means therefor at the suction side of the compressor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B2700/00—Sensing or detecting of parameters; Sensors therefor
- F25B2700/21—Temperatures
- F25B2700/2115—Temperatures of a compressor or the drive means therefor
- F25B2700/21152—Temperatures of a compressor or the drive means therefor at the discharge side of the compressor
Abstract
{Abstract} In a refrigeration / air-conditioning device including a refrigeration cycle (29), and an expansion valve control means (35), the expansion valve control means (35) includes 5 a target value switching means (36) which adopts the lower one of a target degree of discharge superheat TdSH plus a high pressure saturation temperature and an upper-limit value of the discharge temperature Td as a target value, or compares a target discharge temperature Td obtained from 10 calculation of the number of rotations of a compressor and the high pressure saturation temperature with an upper limit value and adopts the lower one of the target discharge temperature Td and the upper-limit value as the target discharge temperature Td while performing the 15 control at the predetermined degree of discharge superheat TdSH or the control at the predetermined discharge temperature Td. C-13 Lu Cl: "-, ,2 - r > -------------~ ------- -- ------- -------C..13-------t CD 'Oo -----------
Description
1 2016213701 07 Oct 2016 {DESCRIPTION} {Title of Invention}
REFRIGERATION / AIR-CONDITIONING DEVICE 5 {Technical Field} [0001]
The present invention relates to a refrigeration / air-conditioning device using a refrigerant whose discharge temperature Td easily increases, e.g., an R32 refrigerant. 10 {Background Art} [0002]
In various types of refrigerators, air conditioners, and heat pumps (hereinafter generically referred to as a 15 refrigeration / air-conditioning device), a liquid floodback to a compressor is prevented by controlling the aperture of an expansion valve so that a degree of suction gas superheat SH becomes constant, to ensure reliability.
On the other hand, an R32 refrigerant or a mixed 20 refrigerant rich in R32 refrigerant, which has a global warming potential (GWP) as low as approximately one-third that of an R410A refrigerant and an ozone depletion potential (ODP) of zero (hereinafter simply referred to as an R32 refrigerant) has been used in recent years to reduce 25 an environment load. 2 2016213701 07 Oct 2016 [0003]
However, the discharge temperature Td of the R32 refrigerant is higher by 10°C to 20°C than that of the R410A refrigerant due to its physical properties. The 5 larger a high-low pressure difference of the refrigerant becomes, the higher the discharge temperature Td tends to be. Thus, when the R410A refrigerant is used, the discharge temperature Td thereof can be controlled to within a temperature range where no breakdown occurs in a 10 compressor motor in a normal utilization range, as illustrated in a Mollier diagram of FIG. 6. However, when the R32 refrigerant is used, the discharge temperature Td thereof exceeds a temperature at which a breakdown occurs in the compressor motor in control at the predetermined 15 degree of suction gas superheat SH, as illustrated in a
Mollier diagram of FIG. 7. Therefore, motor efficiency may decrease and a capability may be unable to be ensured under the condition that the discharge temperature Td easily increases (the high-low pressure difference is large). 20 When an attempt to ensure an operation range is made by solving such a problem, the insulation grade of a motor winding needs to be increased, resulting in higher costs.
[0004]
Therefore, Japanese Unexamined Patent Application, 25 Publication No. 2001-174075 discusses a configuration in 3 2016213701 07 Oct 2016 which the aperture of an electronic expansion valve (EEV) is controlled so that the degree of suction gas superheat SH becomes a predefined temperature while the aperture of the electronic expansion valve (EEV) is controlled based on 5 a discharge temperature Td of a compressor when the discharge temperature Td exceeds an upper-limit value. Japanese Unexamined Patent Application, Publication No. 2014-190632 discusses a configuration in which the number of rotations of a compressor is adjusted so that the 10 compression ratio of the compressor becomes lower than an upper-limit value to set the degree of drying of a refrigerant at an inlet of the compressor to 0.85 or more while the aperture of an electronic expansion valve (EEV) is adjusted so that a degree of discharge superheat TdSH 15 comes closer to a target value. {Citation List} {Patent Literature} [0005] 20 {PTL 1}
Japanese Unexamined Patent Application, Publication No. 2001-174075 {PTL 2}
Japanese Unexamined Patent Application, Publication 25 No. 2014-190632 4 2016213701 07 Oct 2016 {Summary of Invention} {Technical Problem} [0006]
Although the configurations discussed in Japanese 5 unexamined Patent Application, Publication Nos. 2001-174075 and 2014-190632 can prevent the excessive increase in the discharge temperature Td and the decrease in the motor efficiency caused thereby, they cannot sufficiently cope with an increase in a degree of suction gas superheat SH 10 caused by changes in an operation condition and an operation point, a decrease in operation efficiency caused thereby, inhibition of a stable operation by the occurrence of an excessive liquid floodback, or exceedance of a limit value of the discharge temperature Td caused by a change in 15 ambient temperature. Furthermore, the configurations must use control of the number of rotations of the compressor in addition to the control of the aperture of the electronic expansion vale. Therefore, a control system becomes complicated. 20 [0007]
The present invention has been made in view of such a circumstance, and is directed to providing a refrigeration / air-conditioning device capable of ensuring an appropriate operation condition for changes in an operation 25 condition and an operation point only by control of the 5 2016213701 07 Oct 2016 aperture of an electronic expansion valve while ensuring reliability by operating a compressor within a utilization limit. 5 {Solution to Problem} [0008]
To solve the aforementioned issue, a refrigeration / air-conditioning device according to the present invention adopts the following solutions. 10 Specifically, according to an embodiment of the present invention, there is provided a refrigeration / air-conditioning device, including a refrigeration cycle in which at least a compressor, a heat source-side heat exchanger, an electronic expansion valve, and a 15 utilization-side heat exchanger are connected via refrigerant piping and which is filled with a refrigerant whose discharge temperature Td more easily increases than that of an R410A refrigerant, and an expansion valve control means which controls the aperture of the electronic 20 expansion valve at a predetermined degree of suction gas superheat SH when the discharge temperature Td is not more than an upper-limit value and controls the aperture of the electronic expansion valve at a predetermined degree of discharge superheat TdSH or a predetermined discharge 25 temperature Td when the discharge temperature Td exceeds 6 2016213701 07 Oct 2016 the upper-limit value, in which the expansion valve control means includes a target value switching means which switches, when the expansion valve control means is performing the control at the predetermined degree of 5 discharge superheat TdSH while controlling the aperture of the expansion valve at the predetermined degree of discharge superheat TdSH or the predetermined discharge temperature Td, the control at the predetermined degree of discharge superheat TdSH to the control at the 10 predetermined degree of discharge superheat TdSH or the control at the predetermined discharge temperature Td using the lower one of a target degree of discharge superheat TdSH obtained from calculation of the number of rotations of a compressor plus a high pressure saturation temperature 15 and an upper-limit value of the discharge temperature Td as a target value, and compares, when the expansion valve control means is performing the control at the predetermined discharge temperature Td, a target discharge temperature Td obtained from calculation of the number of 20 rotations of the compressor and the high pressure saturation temperature with the upper-limit value and adopts the lower one of the target discharge temperature Td and the upper-limit value as the target discharge temperature Td. 25 7 2016213701 07 Oct 2016 [0009]
According to the embodiment of the present invention, the aperture of the electronic expansion valve is controlled at the predetermined degree of suction gas 5 superheat SH when the discharge temperature Td of a refrigerant discharged from the compressor during an operation is not more than a previously set upper-limit value, and the aperture of the electronic expansion valve is controlled at the predetermined degree of discharge 10 superheat TdSH or the predetermined discharge temperature Td when the discharge temperature Td exceeds the upper-limit value. Therefore, even when an R32 refrigerant whose discharge temperature Td easily increases is used, the discharge temperature Td is prevented from exceeding a 15 utilization upper-limit value, and the insulation grade of a compressor motor is made usable as it is so that an increase in cost can be avoided while the discharge temperature Td is made difficult to increase so that refrigerant oil can be prevented from deteriorating. While 20 the aperture of the expansion valve is being controlled at the predetermined degree of discharge superheat TdSH or the predetermined discharge temperature Td, when the control at the predetermined degree of discharge superheat TdSH is being performed, the control at the predetermined degree of 25 discharge superheat TdSH is switched to the control at the 8 2016213701 07 Oct 2016 predetermined degree of discharge superheat TdSH or the control at the predetermined discharge temperature Td using the lower one of the target degree of discharge superheat TdSH obtained from calculation of the number of rotations 5 of the compressor plus the high pressure saturation temperature and the upper-limit value of the discharge temperature Td as a target value. When the control at the predetermined target discharge temperature Td is being performed, the target discharge temperature Td obtained 10 from calculation of the number of rotations of the compressor and the high pressure saturation temperature is compared with the upper-limit value, and the lower one of the target discharge temperature Td and the upper-limit value is adopted as the target discharge temperature Td. 15 Thus, even when an operation point has changed with the number of rotations of the compressor remaining the same, the aperture of the electronic expansion valve can be controlled using the lower one of the utilization upper-limit value of the discharge temperature Td to be permitted 20 and the target degree of discharge superheat TdSH plus the high pressure saturation temperature as a target value. Therefore, the discharge temperature Td is suppressed to not more than the utilization upper-limit value of the compressor so that a utilization limit can be reliably 25 protected. 9 2016213701 07 Oct 2016 [0010]
Furthermore, in the refrigeration / air-conditioning device according to an embodiment of the present invention, the expansion valve control means further includes a target 5 value varying means which varies the target degree of discharge superheat TdSH or the target discharge temperature Td depending on the number of rotations of the compressor .
[0011] 10 According to the embodiment of the present invention, the expansion valve control means further includes the target value varying means which varies the target degree of discharge superheat TdSH or the target discharge temperature Td depending on the number of rotations of the 15 compressor. Therefore, when the number of rotations of the compressor decreases so that the compression ratio decreases while the aperture of the electronic expansion valve is being controlled at the predetermined degree of discharge superheat TdSH or the predetermined discharge 20 temperature Td, the aperture of the electronic expansion valve is too throttled. As a result, the degree of suction gas superheat SH becomes too high, resulting in a degraded heat exchange performance. However, when the target degree of discharge superheat TdSH or the discharge temperature Td 25 is varied depending on the number of rotations of the 10 2016213701 07 Oct 2016 compressor, the electronic expansion valve is prevented from being too throttled so that an appropriate operation condition can be maintained. Therefore, the degradation of the heat exchange performance occurring because of the 5 degree of suction gas superheat SH becoming too high is suppressed, enabling the refrigeration / air-conditioning device to perform efficient operations.
[0012]
According to another embodiment of the present 10 invention, there is provided a refrigeration / air- conditioning device, including a refrigeration cycle in which at least a compressor, a heat source-side heat exchanger, an electronic expansion valve, and a utilization-side heat exchanger are connected via 15 refrigerant piping and which is filled with a refrigerant whose discharge temperature Td more easily increases than that of an R410A refrigerant, and an expansion valve control means which controls the aperture of the electronic expansion valve at a predetermined degree of suction gas 20 superheat SH when the discharge temperature Td is not more than an upper-limit value and controls the aperture of the electronic expansion valve at a predetermined degree of discharge superheat TdSH or a predetermined discharge temperature Td when the discharge temperature Td exceeds 25 the upper-limit value, in which the expansion valve control 11 2016213701 07 Oct 2016 means further comprises a target value varying means which varies a target degree of discharge superheat TdSH or a target discharge temperature Td depending on the number of rotations of the compressor. 5 [0013]
According to the embodiment of the present invention, the aperture of the electronic expansion valve is controlled at the predetermined degree of suction gas superheat SH when the discharge temperature Td of a 10 refrigerant discharged from the compressor during an operation is not more than a previously set upper-limit value, and the aperture of the electronic expansion valve is controlled at the predetermined degree of discharge superheat TdSH or the predetermined discharge temperature 15 Td when the discharge temperature Td exceeds the upper- limit value. Therefore, even when an R32 refrigerant whose discharge temperature Td easily increases is used, the discharge temperature Td is prevented from exceeding a utilization upper-limit value, and the insulation grade of 20 a compressor motor is made usable as it is so that an increase in cost can be avoided while the discharge temperature Td is made difficult to increase so that refrigerant oil can be prevented from deteriorating. While the aperture of the electronic expansion valve is being 25 controlled at the predetermined degree of discharge 12 2016213701 07 Oct 2016 superheat TdSH or the predetermined discharge temperature Td, when the number of rotations of the compressor decreases so that the compression ratio decreases, the aperture of the electronic expansion valve is too 5 throttled. As a result, the degree of suction gas superheat SH becomes too high, resulting in a degraded heat exchange performance. However, when the target degree of discharge superheat TdSH or the discharge temperature Td is varied depending on the number of rotations of the 10 compressor, the electronic expansion valve is prevented from being too throttled so that an appropriate operation condition can be maintained. Therefore, the degradation of the heat exchange performance occurring because of the degree of suction gas superheat SH becoming too high is 15 suppressed, enabling the refrigeration / air-conditioning device to perform efficient operations. {Advantageous Effects of Invention} [0014] 20 According to the present invention, even when the R32 refrigerant whose discharge temperature Td easily increases is used, the increase in cost can be avoided when the discharge temperature Td is prevented from exceeding the utilization upper-limit value and the insulation grade of 25 the compressor motor is made usable as it is while the 13 2016213701 07 Oct 2016 refrigerant oil can be prevented from deteriorating when the discharge temperature Td is made difficult to increase. Even when the operation point has changed with the number of rotations of the compressor remaining the same, the 5 aperture of the electronic expansion valve can be controlled using the lower one of the utilization upper-limit value of the discharge temperature Td to be permitted and the target degree of discharge superheat TdSH plus the high pressure saturation temperature as the target value. 10 Therefore, the discharge temperature Td is suppressed to not more than the utilization upper-limit value of the compressor so that the utilization limit can be reliably protected.
[0015] 15 According to the present invention, when the number of rotations of the compressor decreases so that the compression ratio decreases while the aperture of the electronic expansion valve is being controlled at the predetermined degree of discharge superheat TdSH or the 20 predetermined discharge temperature Td, the aperture of the electronic expansion valve is too throttled. As a result, the degree of suction gas superheat SH becomes too high, resulting in the degraded heat exchange performance. However, when the target degree of discharge superheat TdSH 25 or the discharge temperature Td is varied depending on the 14 2016213701 07 Oct 2016 number of rotations of the compressor, the electronic expansion valve is prevented from being too throttled so that the appropriate operation condition can be maintained. Therefore, the degradation of the heat exchange performance 5 occurring because of the degree of suction gas superheat SH becoming too high is suppressed, enabling the refrigeration / air-conditioning device to perform efficient operations. {Brief Description of Drawings} 10 [0016] FIG. 1 is a refrigerant circuit diagram of a refrigeration / air-conditioning device according to an embodiment of the present invention. FIG. 2A is a Mollier diagram illustrating meaning of 15 controlling an electronic expansion valve in the refrigeration / air-conditioning device to switch between control at a degree of suction gas superheat SH and control at a degree of discharge superheat TdSH or a discharge temperature Td. 20 FIG. 2B is a Mollier diagram illustrating meaning of controlling the electronic expansion valve in the refrigeration / air-conditioning device to switch between control at a degree of suction gas superheat SH and control at a degree of discharge superheat TdSH or a discharge 25 temperature Td. 15 2016213701 07 Oct 2016 FIG. 3 is a Mollier diagram illustrating meaning of controlling the electronic expansion valve to switch a target value between a utilization upper-limit value of a discharge temperature Td to be permitted as a compressor 5 and a target degree of discharge superheat TdSH or a target discharge temperature Td obtained by calculation. FIG. 4 is a Mollier diagram illustrating meaning of controlling the electronic expansion valve by varying a target degree of discharge superheat TdSH or a discharge 10 temperature Td depending on the number of rotations of the compressor . FIG. 5 is a graph illustrating a relationship between the number of rotations of the compressor and a target degree of discharge superheat TdSH or a discharge 15 temperature Td to be varied depending thereon. FIG. 6 is a Mollier diagram of a refrigeration cycle using an R410A refrigerant. FIG. 7 is a Mollier diagram of a refrigeration cycle using an R32 refrigerant. 20 {Description of Embodiments} [0017]
An embodiment of the present invention will be described below with reference to FIGS. 1 to 5. 25 FIG. 1 is a refrigerant circuit diagram of a 16 2016213701 07 Oct 2016 refrigeration / air-conditioning device according to an embodiment of the present invention.
The refrigeration / air-conditioning device 1 according to the present embodiment includes a heat source-5 side unit (outdoor unit) 2 installed outdoors, and a utilization-side unit (indoor unit) 3 installed in an indoor space to be air-conditioned, which are connected to each other via liquid-side piping 4 and gas-side piping 5.
[0018] 10 The heat source-side unit (outdoor unit) 2 includes pieces of equipment such as a compressor 6 which compresses a refrigerant, a four-direction switching valve 7 which switches a circulation direction of the refrigerant, a heat source-side heat exchanger (outdoor heat exchanger) 8 which 15 heat-exchanges between the refrigerant and ambient air, an electronic expansion valve for heating (EEVH) 9 which depressurizes the refrigerant during heating, a receiver 10 which temporarily stores a liquid refrigerant, an electronic expansion valve for cooling (EEVC) 11 which 20 depressurizes the refrigerant during cooling, a liquid-side operated valve 12 used to connect the liquid-side piping 4, a gas-side operated valve 13 used to connect the gas-side piping 5, and an accumulator 14 which separates a liquid and sucks only a gas refrigerant into the compressor 6. 25 The pieces of equipment are connected, as illustrated, via 17 2016213701 07 Oct 2016 refrigerant piping 15, to constitute a heat source-side refrigerant circuit 16.
[0019]
The heat source-side refrigerant circuit 16 in the 5 heat source-side unit 2 is provided with a high pressure opening/closing unit 17 which opens and closes at the predetermined pressure of high pressure refrigerant gas discharged from the compressor 6 and a discharge temperature sensor (Td temperature sensor) 18 which detects 10 the temperature of the high pressure refrigerant gas discharged from the compressor 6 for refrigerant discharge piping 15A from the compressor 6 while being provided with a low pressure sensor 19 which detects the pressure of low pressure refrigerant gas to be sucked into the compressor 6 15 and a suction temperature sensor 20 which detects the temperature of the low pressure refrigerant gas to be sucked into the compressor 6 for refrigerant suction piping 15B of the compressor 6.
[0020] 20 The heat source-side heat exchanger 8 is provided with a heat exchange temperature sensor 21 which detects the temperature of an intermediate site and a heat exchange temperature sensor 22 which detects the temperature of one end site while being provided with an ambient temperature 25 sensor 23 which detects the temperature of ambient air to 18 2016213701 07 Oct 2016 be vented via an outdoor air blower (not illustrated) for the heat source-side heat exchanger 8.
[0021]
On the other hand, the utilization-side unit (indoor 5 unit) 3 includes a utilization-side heat exchanger (indoor heat exchanger) 25 which is provided for a utilization-side refrigerant circuit 24 and heat-exchanges between a refrigerant and indoor air to be circulated via an indoor air blower (not illustrated) and cools or heats the indoor 10 air, and is served for indoor cooling or heating by blowing out the indoor air cooled or heated by the utilization-side heat exchanger 25 into a room.
[0022]
The utilization-side heat exchanger 25 is provided 15 with a heat exchange temperature sensor 26 which detects the temperature of an intermediate site and a heat exchange temperature sensor 27 which detects the temperature of one end site while being provided with a suction temperature sensor 28 which detects the temperature of the indoor air 20 to be sucked into the utilization-side heat exchanger 25 via the indoor air blower.
[0023]
The heat source-side refrigerant circuit 16 and the utilization-side refrigerant circuit 24 are connected to 25 each other by respectively flare-connecting the liquid-side 19 2016213701 07 Oct 2016 piping 4 and the gas-side piping 5 using the liquid-side operated valve 12 and the gas-side operated valve 13, to constitute a refrigeration cycle 29 serving as a closed cycle, and the refrigeration cycle 29 is filled with a 5 required amount of refrigerant, whose discharge temperature Td more easily increases than that of an R410A refrigerant, like the R32 refrigerant, to constitute the refrigerant and air conditioning apparatus 1.
[0024] 10 In the aforementioned refrigeration cycle 29, the refrigerant, which has been compressed by the compressor 6, is circulated through the heat source-side heat exchanger 8, the receiver 10, the electronic expansion valve for cooling 11, the liquid-side piping 4, the utilization-side 15 heat exchanger 25, the gas-side piping 5, the four- direction switching valve 7, the accumulator 14, and the compressor 6 in this order, as indicated by a solid-line arrow by the four-direction switching valve 7, to form a cooling/air cooling cycle, and the heat source-side heat 20 exchanger 8 and the utilization-side heat exchanger 25 are respectively made to function as a condenser and an evaporator. When air cooled by a heat absorption function of the refrigerant in the evaporator is blown out into a room, a cooling/air cooling operation can be performed. 25 [0025] 20 2016213701 07 Oct 2016
The refrigerant, which has been compressed by the compressor 6, is circulated through the gas-side piping 5, the utilization-side heat exchanger 25, the liquid-side piping 4, the receiver 10, the electronic expansion valve 5 for heating 9, the liquid-side piping 4, the heat source-side heat exchanger 8, the four-direction switching valve 7, the accumulator 14, and the compressor 6 in this order, as indicated by a broken-line arrow by the four-direction switching valve 7, to form a heating/air heating cycle, and 10 the utilization-side heat exchanger 25 and the heat source-side heat exchanger 8 are respectively made to function as a condenser and an evaporator. When air heated by a heat dissipation function of the refrigerant in the condenser is blown out into a room, a heating/air heating operation can 15 be performed.
[0026]
The heat source-side unit (outdoor unit) 2 and the utilization-side unit (indoor unit) 3 are respectively provided with heat source-side and utilization-side 20 controllers 30 and 31 which respectively control the operations of the units 2 and 3, and the controllers 30 and 31 are connected to each other via the communication line 32. Each of the controllers 30 and 31 controls operations of the refrigeration / air-conditioning device 1 by 25 receiving a detection signal input from each of the 21 2016213701 07 Oct 2016 aforementioned sensors and controlling ON/OFF and the number of rotations of the compressor 6, switching of the four-direction switching valve 7, ON/OFF and the number of rotations of the outdoor air blower (not illustrated), the 5 respective apertures of the electronic expansion valve for heating 9 and the electronic expansion valve for cooling 11, ON/OFF and the number of rotations of the indoor air blower (not illustrated) , and the like, as needed, via a microcomputer or the like according to respective control 10 programs stored in storage sections 33 and 34 based on a detection value of the detection signal and an operation signal, a setting signal, or the like input from a remote control (not illustrated).
[0027] 15 In the present embodiment, the heat source-side controller 30 is provided with an expansion valve control means 35 which controls the aperture of the electronic expansion valve for cooling (EEVC) 11 or the electronic expansion valve for heating (EEVH) 9 so that a degree of 20 suction gas superheat SH, which is found from a difference between a detection value by the suction temperature sensor 20 and a detection value by the heat exchange temperature sensor 26 or a saturation temperature at pressure detected by the low pressure sensor 19 during a normal cooling 25 operation while being found from a difference between the 22 2016213701 07 Oct 2016 detection value by the suction temperature sensor 20 and a detection value by the heat exchange temperature sensor 21 or a saturation temperature at pressure detected by the low pressure sensor 19 during a heating operation, becomes 5 constant.
[0028]
The expansion valve control means 35 has a function of switching control at the predetermined degree of suction gas superheat SH to control at a predetermined degree of 10 discharge superheat TdSH or control at a predetermined discharge temperature Td when the temperature (discharge temperature) Td of the refrigerant discharged from the compressor 6, which is detected by the discharge temperature sensor (Td temperature sensor) 18, exceeds a 15 previously set temperature (e.g., 95°C) during normal cooling and heating operations.
The degree of discharge superheat TdSH can be found from a difference between a detection value by the discharge temperature sensor 18 and the detection value by 20 the heat exchange temperature sensor 21 during cooling or the detection value by the heat exchange temperature sensor 26 during heating (if a high pressure sensor is provided, a saturation temperature at pressure detected by the sensor (a high pressure saturation temperature may be used)). 25 [0029] 23 2016213701 07 Oct 2016
In the aforementioned switching control, when the number of rotations of the compressor 6 increases, for example, so that the compression ratio thereof increases, as indicated by a hollow arrow during the control at the 5 predetermined degree of suction gas superheat SH, as illustrated in FIG. 2A, if the predetermined degree of suction gas superheat SH is kept, the discharge temperature Td may exceed a utilization upper-limit value (a thick one-dot and dash line). If the discharge temperature Td 10 exceeds a previously set temperature (a utilization upper-limit value; e.g., 95°C), control of the aperture of the electronic expansion valve for cooling 11 or the electronic expansion valve for heating 9 is switched to control at the predetermined degree of discharge superheat TdSH or control 15 at the predetermined discharge temperature Td.
[0030]
When the control of the aperture of the electronic expansion valve for cooling 11 or the electronic expansion valve for heating 9 is thus switched to the control at the 20 predetermined degree of discharge superheat TdSH or the control at the predetermined discharge temperature Td, a function of compression by the compressor 6 is controlled as indicated by a hollow arrow, as illustrated in FIG. 2B, so that the discharge temperature Td can be suppressed to a 25 temperature within a utilization limit where no breakdown 24 2016213701 07 Oct 2016 occurs in a motor winding of the compressor 6. In this case, the degree of suction gas superheat SH becomes zero or less (in a region on the left side of a saturated gas line), as illustrated in FIG. 2B. Therefore, humid gas is 5 sucked in so that an operation in a slight liquid floodback state is performed. However, when the degree of discharge superheat TdSH is kept sufficiently high, reliability can be ensured.
[0031] 10 Furthermore, while the aforementioned expansion valve control means 35 is controlling the aperture of the electronic expansion valve for cooling 11 or the electronic expansion valve for heating 9 at the predetermined degree of discharge superheat TdSH or the predetermined discharge 15 temperature Td, when an operation point has changed with the number of rotations of the compressor 6 remaining the same (e.g., an ambient temperature has increased and high pressure has increased during a cooling operation), the operation point may change, as indicated by a broken line 20 in FIG. 3. Therefore, in this case, even if the degree of discharge superheat TdSH is controlled to be constant, the discharge temperature Td may exceed the utilization upper-limit value.
[0032] 25
To avoid such a situation, a target value switching 25 2016213701 07 Oct 2016 means 36 is provided for the expansion valve control means 35. The target value switching means 36 compares, while the control is being performed at the predetermined degree of discharge superheat TdSH or the predetermined discharge 5 temperature Td, a target degree of discharge superheat TdSH obtained from calculation from the number of rotations of the compressor 6 plus the high pressure saturation temperature with a utilization upper-limit value of the discharge temperature Td to be permitted as the compressor 10 6 when the control is being performed at the predetermined degree of discharge superheat TdSH, and switches between the control at the predetermined degree of discharge superheat TdSH and the control at the predetermined discharge temperature Td using the lower one of the values 15 as a target value.
[0033]
The aforementioned target value switching means 36 compares, while the control is being performed at the predetermined degree of discharge superheat TdSH or the 20 predetermined discharge temperature Td, a target discharge temperature Td obtained by calculation from the number of rotations of the compressor 6 and the high pressure saturation temperature with the utilization upper-limit value of the discharge temperature Td to be permitted as 25 the compressor 6 when the control is being performed at the 26 2016213701 07 Oct 2016 predetermined discharge temperature Td, and performs the control at the predetermined discharge temperature Td using the lower one of the values as a target value.
[0034] 5 Furthermore, in the present embodiment, a target value varying means 37, which varies a target value of the degree of discharge superheat TdSH or the discharge temperature Td depending on the number of rotations of the compressor 6 while the aperture of the electronic expansion valve for 10 cooling 11 or the electronic expansion value for heating 9 is being controlled at the predetermined degree of discharge superheat TdSH or the predetermined discharge temperature Td, is provided for the expansion valve control means 35. 15 [0035]
Generally, when the number of rotations of the compressor 6 decreases, the performance of the heat exchanger remains unused. Therefore, high pressure decreases, low pressure increases, and a compression ratio 20 decreases. Thus, if the target degree of discharge superheat TdSH or the target discharge temperature Td remains constant, as illustrated in FIG. 4, the degree of suction gas superheat SH may be higher than a control value during the control at the predetermined degree of suction 25 gas superheat SH, as indicated by a fine broken line as a 27 2016213701 07 Oct 2016 result. Therefore, the target value varying means 37 which varies the target value of the degree of discharge superheat TdSH or the discharge temperature Td depending on the number of rotations of the compressor 6 is provided, to 5 prevent the electronic expansion valve for cooling 11 or the electronic expansion valve for heating 9 from being too throttled.
[0036]
In this case, a relationship between the number of 10 rotations of the compressor 6 and the degree of discharge superheat TdSH or the discharge temperature Td may be set so that the target value of the degree of discharge superheat TdSH or the discharge temperature Td linearly varies within a predetermined rotation number range, as 15 illustrated in FIG. 5. If the degree of discharge superheat TdSH or the discharge temperature Td becomes too low, a liquid floodback state occurs. Therefore, the target value (the degree of discharge superheat TdSH or the discharge temperature Td) which is a predetermined value or 20 more is ensured. When the degree of discharge superheat
TdSH or the discharge temperature Td becomes too high, the discharge temperature Td exceeds the utilization upper-limit value. Therefore, the discharge temperature Td is set to remain unchanged at a given value. 25 [0037] 28 2016213701 07 Oct 2016
When the degree of suction gas superheat SH is becoming high, as illustrated in FIG. 4, the control at the predetermined degree of discharge superheat TdSH or the control at the predetermined discharge temperature Td is 5 basically returned to the control at the predetermined degree of suction gas superheat SH. However, when the control is frequently switched, a stable operation is inhibited. Therefore, hysteresis may be provided so that the control is not switched until the degree of suction gas 10 superheat SH increases to some extent or the degree of discharge superheat TdSH or the discharge temperature Td decreases by not less than a defined value if the control is switched once.
[0038] 15 According to the present embodiment as described above, the following function and effect are produced.
In the aforementioned refrigeration / air-conditioning device 1, when the high temperature and pressure refrigerant gas discharged from the compressor 6 is 20 circulated in the direction indicated by the solid-line arrow by the four-direction switching valve 7, to form the cooling/air cooling cycle, and the heat source-side heat exchanger 8 and the utilization-side heat exchanger 25 are respectively made to function as a condenser and an 25 evaporator, the cooling/air cooling operation can be 29 2016213701 07 Oct 2016 performed. On the other hand, when the high temperature and pressure refrigerant gas discharged from the compressor 6 is circulated in the direction indicated by the broken-line arrow by the four-direction switching valve 7, to form 5 the heating/air heating cycle, and the utilization-side heat exchanger 25 and the heat source-side heat exchanger 8 are respectively made to function as a condenser and an evaporator, the heating/air heating operation can be performed. 10 [0039]
During the cooling/air cooling and heating/air heating operations, the aperture of the electronic expansion valve for cooling (EEVC) 11 or the electronic expansion valve for heating (EEVH) 9 is controlled so that the degree of 15 suction gas superheat SH becomes constant via the expansion valve control means 35. When the discharge temperature Td of the refrigerant detected by the discharge temperature sensor 18 exceeds the previously set utilization upper-limit value (95°C in the present embodiment) during the 20 operations, the control at the predetermined degree of suction gas superheat SH is switched to the control at the predetermined degree of discharge superheat TdSH or the control at the predetermined discharge temperature Td.
[0040] 25 As a result, even when the R32 refrigerant whose 30 2016213701 07 Oct 2016 discharge temperature Td more easily increases than that of the R410A refrigerant is used, an operation having high reliability can be performed by controlling the degree of suction gas superheat SH to be constant to reliably prevent 5 a liquid floodback in a low compression ratio region, and the discharge temperature Td can be prevented from exceeding the utilization upper-limit value by performing an operation in a slight liquid floodback state and an increase in cost can be avoided by making the insulation 10 grade of a compressor motor usable as it is in a region where the discharge temperature Td easily increases in a high compression ratio. Moreover, when the discharge temperature Td is made difficult to increase, refrigerant oil can be prevented from deteriorating. 15 [0041]
When the electronic expansion valve for cooling 11 or the electronic expansion valve for heating 9 is controlled at the predetermined degree of discharge superheat TdSH or the predetermined discharge temperature Td, the discharge 20 temperature Td may change depending on a high pressure level during an operation. For example, when the ambient temperature increases so that the high pressure increases during cooling, the operation point changes with the number of rotations of the compressor 6 remaining the same. When 25 only the degree of discharge superheat TdSH is controlled, 31 2016213701 07 Oct 2016 as illustrated in FIG. 3, the discharge temperature Td may exceed the permitted utilization upper-limit value.
[0042]
However, while the control is being performed at the 5 predetermined degree of discharge superheat TdSH or the predetermined discharge temperature Td, as described above, the target value switching means 36 compares the target degree of discharge superheat TdSH obtained from calculation from the number of rotations of the compressor 10 6 plus the high pressure saturation temperature with the utilization upper-limit value of the discharge temperature Td to be permitted as the compressor 6 and switches between the control at the predetermined degree of discharge superheat TdSH and the control at the predetermined 15 discharge temperature Td using the lower one of the values as a target value when the control is being performed at the predetermined degree of discharge superheat TdSH. The target value switching means 36 compares the target discharge temperature Td obtained by calculation from the 20 number of rotations of the compressor 6 and the high pressure saturation temperature with the utilization upper-limit value of the discharge temperature Td to be permitted as the compressor 6 and performs the control at the predetermined discharge temperature Td adopting the lower 25 one of the values as a target value when the control is 32 2016213701 07 Oct 2016 being performed at the predetermined discharge temperature Td.
[0043]
Therefore, even if the operation point has changed 5 with the number of rotations of the compressor 6 remaining the same, as described above, when the aperture of the electronic expansion valve for cooling 11 or the electronic expansion valve for heating 9 is controlled using the lower one of the upper-limit value of the discharge temperature 10 Td to be permitted and the target degree of discharge superheat TdSH plus the high pressure saturation temperature as a target value, the discharge temperature Td is suppressed to not more than the utilization upper-limit value of the compressor 6 so that the utilization limit can 15 be protected.
[0044]
Furthermore, in the present embodiment, the target value varying means 37, which varies the target value of the degree of discharge superheat TdSH or the discharge 20 temperature Td depending on the number of rotations of the compressor 6, is provided for the expansion valve control means 35. More specifically, when the number of rotations of the compressor 6 decreases so that the compression ratio decreases while the aperture of the electronic expansion 25 valve for cooling 11 or the electronic expansion valve for 33 2016213701 07 Oct 2016 heating 9 is being controlled at the predetermined degree of discharge superheat TdSH or the predetermined discharge temperature Td, the aperture of the electronic expansion valve for cooling 11 or the electronic expansion valve for 5 heating 9 is too throttled if the target degree of discharge superheat TdSH or the discharge temperature Td is constant. As a result, the degree of suction gas superheat SH becomes too high, resulting in a degraded heat exchange performance . 10 [0045]
Accordingly, when the target value varying means 37 varies the degree of discharge superheat TdSH or the discharge temperature Td serving as the target value, as illustrated in FIG. 5, depending on the number of rotations 15 of the compressor 6, efficient operations can be performed with an appropriate operation condition maintained.
[0046]
The present invention is not limited to the invention according to the aforementioned embodiment, and 20 modifications can be made, as needed, without departing from the scope of the present invention. For example, in the aforementioned present embodiment, an example in which the degree of discharge superheat TdSH and the discharge temperature Td are conveniently treated equally, the degree 25 of discharge superheat TdSH is made variable, and the 34 2016213701 07 Oct 2016 discharge temperature Td is made constant has been described for a form for varying the degree of discharge superheat TdSH or the discharge temperature Td serving as a control target value depending on the number of rotations 5 of the compressor 6. However, a configuration using a relationship between the high pressure saturation temperature and the target discharge temperature Td as a map may be used without the degree of discharge superheat TdSH being used. 10 [0047]
Furthermore, while an example of the refrigeration / air-conditioning device 1 in which the electronic expansion valve for heating (EEVH) 9 and the electronic expansion valve for cooling (EEVC) 11 are separately provided has 15 been described in the aforementioned embodiment, a configuration using a single electronic expansion valve (EEV) may be used. Alternatively, a configuration in which the electronic expansion valve for cooling (EEVC) 11 is disposed within the utilization-side unit (indoor unit) 3 20 may be used. The refrigeration cycle 29 may have a basic cycle including a compressor, a heat source-side heat exchanger, an electronic expansion valve, and a utilization-side heat exchanger, is not limited to the refrigeration cycle in the aforementioned embodiment, and 25 may be deformable to cycles having various configurations. 2016213701 07 Oct 2016 35 {Reference Signs List} [0048] I Refrigeration / air-conditioning device 6 Compressor 8 Heat source-side heat exchanger 9 Electronic expansion valve for heating (EEVH) II Electronic expansion valve for cooling (EEVC) 15 Refrigerant piping 18 Discharge temperature sensor 19 Low pressure sensor 20 Suction temperature sensor 21, 22, 26, 27 Heat exchange temperature sensor 29 Refrigeration cycle 30 Heat source-side controller 31 Utilization-side controller 35 Expansion valve control means 36 Target value switching means 37 Target value varying means
Claims (3)
- {CLAIMS}1. A refrigeration / air-conditioning device comprising: a refrigeration cycle in which at least a compressor, a heat source-side heat exchanger, an electronic expansion valve, and a utilization-side heat exchanger are connected via refrigerant piping and which is filled with a refrigerant whose discharge temperature Td more easily increases than that of an R410A refrigerant; and an expansion valve control means which controls an aperture of the electronic expansion valve at a predetermined degree of suction gas superheat SH when the discharge temperature Td is not more than an upper-limit value and controls the aperture of the electronic expansion valve at a predetermined degree of discharge superheat TdSH or a predetermined discharge temperature Td when the discharge temperature Td exceeds the upper-limit value, wherein the expansion valve control means comprises a target value switching means which switches, when the expansion valve control means is performing the control at the predetermined degree of discharge superheat TdSH while controlling the aperture of the expansion valve at the predetermined degree of discharge superheat TdSH or the predetermined discharge temperature Td, the control at the predetermined degree of discharge superheat TdSH to the control at the predetermined degree of discharge superheat TdSH or the control at the predetermined discharge temperature Td using the lower one of a target degree of discharge superheat TdSH obtained from calculation of the number of rotations of a compressor plus a high pressure saturation temperature and an upper-limit value of the discharge temperature Td as a target value, and compares, when the expansion valve control means is performing the control at the predetermined discharge temperature Td, a target discharge temperature Td obtained from calculation of the number of rotations of the compressor and the high pressure saturation temperature with the upper-limit value and adopts the lower one of the target discharge temperature Td and the upper-limit value as the target discharge temperature Td.
- 2. The refrigeration / air-conditioning device according to claim 1, wherein the expansion valve control means further comprises a target value varying means which varies the target degree of discharge superheat TdSH or the target discharge temperature Td depending on the number of rotations of the compressor.
- 3. A refrigeration / air-conditioning device comprising: a refrigeration cycle in which at least a compressor, a heat source-side heat exchanger, an electronic expansion valve, and a utilization-side heat exchanger are connected via refrigerant piping and which is filled with a refrigerant whose discharge temperature Td more easily increases than that of an R410A refrigerant; and an expansion valve control means which controls an aperture of the electronic expansion valve at a predetermined degree of suction gas superheat SH when the discharge temperature Td is not more than an upper-limit value and controls the aperture of the electronic expansion valve at a predetermined degree of discharge superheat TdSH or a predetermined discharge temperature Td when the discharge temperature Td exceeds the upper-limit value, wherein the expansion valve control means further comprises a target value varying means which varies a target degree of discharge superheat TdSH or a target discharge temperature Td depending on the number of rotations of the compressor.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2015158200A JP6594698B2 (en) | 2015-08-10 | 2015-08-10 | Refrigeration and air conditioning equipment |
| JP2015-158200 | 2015-08-10 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU2016213701A1 true AU2016213701A1 (en) | 2017-03-02 |
| AU2016213701B2 AU2016213701B2 (en) | 2017-11-30 |
Family
ID=57046947
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU2016213701A Active AU2016213701B2 (en) | 2015-08-10 | 2016-08-08 | Refrigeration / air-conditioning device |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP3130870B1 (en) |
| JP (1) | JP6594698B2 (en) |
| AU (1) | AU2016213701B2 (en) |
Families Citing this family (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6767841B2 (en) * | 2016-10-14 | 2020-10-14 | サンデン・オートモーティブクライメイトシステム株式会社 | Vehicle air conditioner |
| WO2019113094A1 (en) * | 2017-12-06 | 2019-06-13 | Johnson Controls Technology Company | Control system and a control method for a hvac unit and a media comprising such processor-executable instructions |
| US10955179B2 (en) * | 2017-12-29 | 2021-03-23 | Johnson Controls Technology Company | Redistributing refrigerant between an evaporator and a condenser of a vapor compression system |
| KR102067447B1 (en) * | 2018-01-25 | 2020-01-20 | 삼성전자주식회사 | Air conditioner and control method thereof |
| CN109798626A (en) * | 2019-01-07 | 2019-05-24 | 广东美的暖通设备有限公司 | The control method and device of the electric expansion valve of outer machine heat exchanger |
| CN112556127B (en) * | 2019-09-10 | 2022-03-11 | 广东美的制冷设备有限公司 | Air conditioner cold accumulation control method and device and computer readable storage medium |
| IT201900021534A1 (en) * | 2019-11-19 | 2021-05-19 | Carel Ind Spa | CO2 SINGLE VALVE REFRIGERATOR AND REGULATION METHOD OF THE SAME |
| CN111664559B (en) * | 2020-06-28 | 2021-08-24 | 珠海拓芯科技有限公司 | Control method and device of electronic expansion valve and air conditioner |
| CN112710071B (en) * | 2020-12-28 | 2022-07-26 | 宁波奥克斯电气股份有限公司 | Method and device for controlling adjusting speed of electronic expansion valve and multi-split air conditioning system |
| CN113639436B (en) * | 2021-08-02 | 2022-12-23 | 海尔(深圳)研发有限责任公司 | Method and device for adjusting heat exchange quantity of air conditioner outdoor unit and air conditioner outdoor unit |
| JP7139031B1 (en) | 2022-02-15 | 2022-09-20 | 日立ジョンソンコントロールズ空調株式会社 | air conditioner |
| EP4343233A1 (en) | 2022-09-20 | 2024-03-27 | Ariston S.P.A. | Optimized management method of an environmentally friendly heat pump |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0689949B2 (en) * | 1988-06-10 | 1994-11-14 | 株式会社日立製作所 | Air conditioner |
| JP3465654B2 (en) * | 1999-12-14 | 2003-11-10 | ダイキン工業株式会社 | Refrigeration equipment |
| JP3760259B2 (en) * | 2000-04-21 | 2006-03-29 | 株式会社日立製作所 | Air conditioner |
| JP5386141B2 (en) * | 2008-10-23 | 2014-01-15 | 三菱重工業株式会社 | Heat pump device control method, heat pump device outdoor unit and heat pump device |
| JP5981376B2 (en) * | 2013-03-27 | 2016-08-31 | ジョンソンコントロールズ ヒタチ エア コンディショニング テクノロジー（ホンコン）リミテッド | Air conditioner and method of operating air conditioner |
| EP2955462B1 (en) * | 2013-06-20 | 2020-10-14 | Mitsubishi Electric Corporation | Heat pump apparatus |
| JP6321363B2 (en) * | 2013-12-06 | 2018-05-09 | シャープ株式会社 | Air conditioner |
-
2015
- 2015-08-10 JP JP2015158200A patent/JP6594698B2/en active Active
-
2016
- 2016-08-08 EP EP16183268.8A patent/EP3130870B1/en active Active
- 2016-08-08 AU AU2016213701A patent/AU2016213701B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| EP3130870A1 (en) | 2017-02-15 |
| EP3130870B1 (en) | 2018-05-09 |
| JP2017036881A (en) | 2017-02-16 |
| JP6594698B2 (en) | 2019-10-23 |
| AU2016213701B2 (en) | 2017-11-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2016213701B2 (en) | Refrigeration / air-conditioning device | |
| US10527330B2 (en) | Refrigeration cycle device | |
| JP2016008742A (en) | Air conditioning device | |
| CN109790995B (en) | Air conditioner | |
| AU2014411657B2 (en) | Air-conditioning apparatus | |
| US10598413B2 (en) | Air-conditioning apparatus | |
| US11428422B2 (en) | Air conditioning system | |
| WO2016103552A1 (en) | Air conditioner | |
| KR102082881B1 (en) | Multi-air conditioner for heating and cooling operations at the same time | |
| JP2008190759A (en) | Air conditioner | |
| WO2015060384A1 (en) | Refrigeration device | |
| JP6755396B2 (en) | Air conditioner | |
| JP2012013365A (en) | Air conditioner | |
| WO2020262624A1 (en) | Refrigeration device | |
| JP2014070830A (en) | Freezer unit | |
| JP2008298379A (en) | Reheat type air conditioner | |
| US11448433B2 (en) | Refrigeration apparatus | |
| WO2020003490A1 (en) | Air conditioning device | |
| JP6573723B2 (en) | Air conditioner | |
| KR101186326B1 (en) | Air-Condition and the control method for the same | |
| JP2002243307A (en) | Air conditioning apparatus | |
| KR102000641B1 (en) | Air conditioning apparatus for communication equipment having emergency control function | |
| JP5999163B2 (en) | Air conditioner | |
| JP2003106606A (en) | Dew condensation prevention control method for air conditioner | |
| JP2014070829A (en) | Refrigerator |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PC1 | Assignment before grant (sect. 113) |
Owner name: MITSUBISHI HEAVY INDUSTRIES THERMAL SYSTEMS, LTD. Free format text: FORMER APPLICANT(S): MITSUBISHI HEAVY INDUSTRIES, LTD. |
|
| DA3 | Amendments made section 104 |
Free format text: THE NATURE OF THE AMENDMENT IS: AMEND THE INVENTION TITLE TO READ REFRIGERATION / AIR-CONDITIONING DEVICE |
|
| FGA | Letters patent sealed or granted (standard patent) |