CN110382970B - Air conditioner - Google Patents

Air conditioner Download PDF

Info

Publication number
CN110382970B
CN110382970B CN201880014547.3A CN201880014547A CN110382970B CN 110382970 B CN110382970 B CN 110382970B CN 201880014547 A CN201880014547 A CN 201880014547A CN 110382970 B CN110382970 B CN 110382970B
Authority
CN
China
Prior art keywords
temperature
indoor heat
heat exchange
indoor
exchange temperature
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.)
Active
Application number
CN201880014547.3A
Other languages
Chinese (zh)
Other versions
CN110382970A (en
Inventor
本条秀树
渡边宜仁
奥野大树
西川顺之佑
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fujitsu General Ltd
Original Assignee
Fujitsu General Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from JP2017036408A external-priority patent/JP6824779B2/en
Priority claimed from JP2017184926A external-priority patent/JP6399181B1/en
Application filed by Fujitsu General Ltd filed Critical Fujitsu General Ltd
Publication of CN110382970A publication Critical patent/CN110382970A/en
Application granted granted Critical
Publication of CN110382970B publication Critical patent/CN110382970B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F1/00—Room units for air-conditioning, e.g. separate or self-contained units or units receiving primary air from a central station
    • F24F1/0007—Indoor units, e.g. fan coil units
    • F24F1/0059—Indoor units, e.g. fan coil units characterised by heat exchangers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00—Control or safety arrangements
    • F24F11/70—Control systems characterised by their outputs; Constructional details thereof
    • F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
    • F24F11/86—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling compressors within refrigeration or heat pump circuits
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
    • F24F13/22—Means for preventing condensation or evacuating condensate
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2110/00—Control inputs relating to air properties
    • F24F2110/10—Temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2140/00—Control inputs relating to system states
    • F24F2140/20—Heat-exchange fluid temperature
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24—HEATING; RANGES; VENTILATING
    • F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F2140/00—Control inputs relating to system states
    • F24F2140/30—Condensation of water from cooled air

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

The present invention can provide an air conditioner, wherein in protection control during indoor heat exchange heating operation, if the indoor heat exchange temperature (Tc) is equal to or higher than a second threshold indoor heat exchange temperature (Tch2) higher than a first threshold indoor heat exchange temperature (Tch1) under protection control during heating operation, a compressor (21) is stopped. Alternatively, if the discharge temperature (Td) is equal to or higher than a first threshold discharge temperature (Tdh1) in the protection control during heating operation, the compressor (21) is stopped. Alternatively, as a control that is not executed in the protection control during the heating operation, if the outdoor heat-exchange temperature (Te) is equal to or higher than the threshold outdoor heat-exchange temperature (Teh), the compressor (21) is stopped to suppress an increase in the suction pressure of the compressor (21). Thus, the discharge pressure of the compressor does not exceed the upper limit of the range of use during operation to reduce the number of mold and bacteria.

Description

Air conditioner
Technical Field
The present invention relates to an air conditioner that suppresses the growth of mold and bacteria in an indoor unit.
Background
When the air conditioner performs a cooling operation, dew condensation water is generated in the indoor heat exchanger functioning as an evaporator. Dew condensation water generated in the indoor heat exchanger becomes a main cause of propagation of mold and bacteria in the indoor heat exchanger, and when mold and bacteria propagate, the air-conditioning air blown out of the indoor unit becomes unpleasant odor. Therefore, an air conditioner that dries the inside of an indoor unit including an indoor heat exchanger after a cooling operation has been proposed (see, for example, patent document 1 or patent document 2).
Documents of the prior art
Patent document
Patent document 1: japanese laid-open patent publication No. 10-62000
Patent document 2: japanese patent laid-open publication No. 2016-65687
Disclosure of Invention
Technical problem to be solved by the invention
In the air conditioners described in patent documents 1 and 2, an indoor heat exchanger is heated in order to dry the interior of an indoor unit after a cooling operation. However, in the heating for drying as described above, the temperature of the indoor heat exchanger is not greatly different from the temperature during the heating operation, and the number of mold and bacteria is not reduced. In general, in the operation of drying the inside of the indoor unit as described above, the temperature of the indoor heat exchanger is set to about 40 ℃.
In order to reduce the number of mold and bacteria, it is conceivable to further heat the indoor heat exchanger and raise the temperature of the indoor heat exchanger, for example, to set the target temperature of the indoor heat exchanger to 50 ℃. In this case, in order to greatly reduce the number of mold and bacteria in a short time, it is desirable to increase the target temperature as much as possible.
On the other hand, in the air conditioner, it is possible to perform protection control that avoids the discharge pressure of the compressor from exceeding the upper limit value of the usage range. As one of the protection controls, a temperature lower than a temperature corresponding to an upper limit value of a use range of a discharge pressure of the compressor is set as a threshold temperature, and the compressor is stopped when an indoor heat exchange temperature exceeds the threshold temperature.
In the air conditioner capable of protection control as described above, when the indoor heat exchanger is heated to reduce the number of mold and bacteria, if the threshold temperature of the protection control is lower than the target temperature of the indoor heat exchanger at the time of sterilization, the compressor is stopped by the protection control until the indoor heat exchange temperature reaches the target temperature, and therefore, there is a problem that the number of mold and bacteria cannot be reduced.
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an air conditioner in which the discharge pressure of a compressor does not exceed the upper limit of the usage range during operation for reducing the number of mold and bacteria.
Means for solving the problems
In order to solve the above-described problems, an air conditioner according to the present invention includes: an indoor unit having an indoor heat exchanger and an indoor heat exchange temperature sensor for detecting an indoor heat exchange temperature, which is a temperature of the indoor heat exchanger; an outdoor unit having a compressor; and a control unit that controls the compressor. The control unit may execute a first protection control and a second protection control when the indoor heat exchanger is caused to function as a condenser, the first protection control being executed if the indoor heat exchange temperature reaches a temperature higher than a predetermined first threshold indoor heat exchange temperature, and the second protection control being executed if the indoor heat exchange temperature reaches a temperature higher than a predetermined second threshold indoor heat exchange temperature higher than the first threshold indoor heat exchange temperature.
Effects of the invention
According to the air conditioner of the present invention configured as described above, the second protection control is performed if the indoor heat exchange temperature reaches a temperature higher than a predetermined second threshold indoor heat exchange temperature higher than the first threshold indoor heat exchange temperature. Therefore, the discharge pressure of the compressor can be made not to exceed the upper limit of the use range during the operation for reducing the number of mold and bacteria.
Drawings
Fig. 1 is an explanatory view of an air conditioner according to an embodiment of the present invention, in which fig. 1 (a) is an external perspective view of an indoor unit and an outdoor unit, and fig. 1 (B) is an X-X sectional view of (a).
Fig. 2 is an explanatory view of an air conditioner according to an embodiment of the present invention, fig. 2 (a) is a refrigerant circuit diagram, and fig. 2 (B) is a block diagram of an outdoor unit control unit and an indoor unit control unit.
Fig. 3 is a flowchart showing a process flow of the heating operation control.
Fig. 4 is a flowchart showing a process flow of the protection control during the heating operation.
Fig. 5 is data showing the remaining rate of mold or bacteria at each indoor heat exchange temperature, fig. 5 (a) is data on mold, and fig. 5 (B) is data on coliform bacteria.
Fig. 6 is a control table of each fan in the indoor heat exchange heating operation, where fig. 6 (a) is an indoor fan control table, and fig. 6 (B) is an outdoor fan control table.
Fig. 7 is a flowchart showing a processing flow of a main routine of the indoor heat exchange heating operation.
Fig. 8 is a subroutine of the indoor heat exchange heating operation, and is a flowchart showing a process flow of the pre-heating operation control.
Fig. 9 is a subroutine of the indoor heat exchange heating operation, and is a flowchart showing a process flow of the indoor fan control during temperature maintenance.
Fig. 10 is a subroutine of the indoor heat exchange heating operation, and is a flowchart showing a process flow of the outdoor fan control during temperature maintenance.
Fig. 11 is a flowchart showing a processing flow of the protection control during the indoor heat exchange heating operation.
Fig. 12 is a flowchart showing a process flow of the wetting control operation.
Description of the symbols
1 … air conditioner
2 … outdoor unit
3 … indoor unit
10 … refrigerant circuit
21 … compressor
27 … outdoor fan
32 … indoor fan
35 … up-down wind direction board
71 … discharge temperature sensor
72 … outdoor heat exchange temperature sensor
73 … outside air temperature sensor
74 … indoor heat exchange temperature sensor
75 … indoor temperature sensor
200 … outdoor unit control unit
210 … outdoor unit CPU
300 … indoor unit control unit
310 … indoor machine CPU
400 … indoor fan control table
500 … outdoor fan control table
Tc … indoor heat exchange temperature
Tch1 … first threshold indoor Heat exchange temperature
Tch2 … second threshold indoor Heat exchange temperature
Tc 1-Tc 5 … first-fifth threshold indoor heat exchange temperature
Delta Tc … indoor heat exchange temperature variation
Te … outdoor heat exchange temperature
Teh … threshold outdoor heat exchange temperature
Td … discharge temperature
Tdh1 … first threshold discharge temperature
Tdh2 … second threshold discharge temperature
Indoor temperature of Ti …
Tip … threshold indoor temperature
To … outside air temperature
Top1 … first threshold outside air temperature
Top2 … second threshold outside air temperature
Top3 … third threshold outside air temperature
Tp … set temperature
Delta T … temperature difference
First Upper and lower Chamber Heat exchange temperature Tch1 …
Second Upper and lower Chamber Heat exchange temperature Tch2 …
tp1 … first prescribed time
tp2 … second prescribed time
tp3 … third prescribed time
tc … compressor Release Interval time
tfi … indoor fan release interval time
Rc … compressor speed
Compressor discharge speed
Minimum rotation speed of Rcm … compressor
Rfi … indoor fan speed
Rfia … Forward indoor Fan speed of heating
Rfir … indoor fan discharge speed
Minimum speed of indoor fan Rfim …
Initial speed of indoor fan Rfip …
Rfo … outdoor fan speed
Rfoa … heating front outdoor fan speed
Rfob … maintains outdoor fan speed
Opening of D … expansion valve
Dp … specifies the opening degree of the expansion valve
Detailed Description
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the embodiment, an air conditioner in which an outdoor unit and an indoor unit are connected by two refrigerant pipes will be described as an example. The present invention is not limited to the following embodiments, and various modifications may be made without departing from the scope of the present invention.
[ examples ]
As shown in fig. 1 (a), the air conditioner 1 of the present embodiment includes an outdoor unit 2 installed outdoors, and an indoor unit 3 installed indoors and connected to the outdoor unit 2 through a liquid pipe 4 and an air pipe 5.
< shape of indoor Unit and arrangement of devices >
The indoor unit 3 includes an indoor unit casing 30 formed in a substantially rectangular parallelepiped shape and having a horizontal length. The indoor unit casing 30 is formed of a top panel 30a, a right side panel 30b, a left side panel 30c, a bottom panel 30d, and a front panel 30 e. All of these panels are formed using a resin material.
The top panel 30a is formed in a substantially rectangular shape, and forms the top surface of the indoor unit casing 30. As shown in fig. 1 (B), the ceiling panel 30a is provided with a suction port 30f for taking indoor air into the indoor unit 3. Although not shown, the suction port 30f is formed in a mesh shape.
The right and left side panels 30b and 30c form the left and right side surfaces of the indoor unit casing 30. The right and left side panels 30b and 30c are formed as curved surfaces having a predetermined curvature, and have a bilaterally symmetrical shape.
The bottom panel 30d is formed in a substantially square shape and forms the bottom surface of the indoor unit casing 30. As shown in fig. 1 (B), a base 30j described later is fixed to the bottom panel 30 d.
The front panel 30e is formed in a substantially square shape and is disposed so as to cover the front surface of the indoor unit casing 30. The front panel 30e forms a design surface of the indoor unit 3.
As described above, the suction port 30f is provided in the top panel 30a, and the discharge port 30g for discharging the indoor air, which has exchanged heat with the refrigerant in the indoor heat exchanger 31 described later, into the room is provided below the front panel 30 e. An indoor fan 32 for sucking indoor air from the suction port 30f and blowing it out from the blow-out port 30g is provided in the air passage 30h connecting the suction port 30f and the blow-out port 30 g. Further, an indoor heat exchanger 31 formed in an inverted V shape by having a bent portion 30n is disposed above the indoor fan 32. The indoor heat exchanger 31 and the indoor fan 32 are fixed to a base 30j for mounting the indoor unit 3 on a wall surface.
The air outlet 30g is formed by the lower portion of the base 30j and the lower surface of the casing 30k attached to the front panel 30 e. The upper surfaces of the base 30j and the casing 30k are set as a drain pan 30m that receives dew condensation water generated in the indoor heat exchanger 31.
Two vertical wind direction plates 35 that vertically deflect the air blown out from the air outlet 30g are provided in the air outlet 30 g. The two vertical vanes 35 are each formed of a resin material, and are formed in such a shape that each vertical vane 35 can rotate to close the air outlet 30g when the indoor unit 3 is stopped. The vertical wind direction plates 35 are fixed to a rotation shaft, not shown, and the air blown out from the air outlet 30g is deflected in the vertical direction by the vertical wind direction plates 35 rotating in the vertical direction.
A plurality of horizontal wind direction plates 36 that deflect air blown out from the air outlet 30g in the horizontal direction are provided on the upstream side of the air outlet 30g (the inside of the indoor unit casing 30) as viewed from the vertical wind direction plate 35. Each of the horizontal vanes 36 is made of a resin material, is fixed to a rotation shaft, not shown, and deflects the air blown out from the air outlet 30g in the horizontal direction by the horizontal vanes 36 rotating in the horizontal direction.
A filter 38 for removing dust contained in the air taken into the indoor unit 3 is disposed on the upstream side of the indoor heat exchanger 31 in the air passage 30h (between the indoor heat exchanger 31 and the suction port 30 f). The filter 38 is formed by weaving fibers made of a resin material in a mesh pattern, for example. When the indoor air taken into the interior of the housing 30 of the indoor unit 3 from the suction port 30f passes through the filter 38, dust contained in the indoor air and larger than the mesh size of the filter 38 is captured by the filter 38.
< Structure of air conditioner and refrigerant Circuit >
Next, the refrigerant circuit of the air conditioner 1, which is formed by connecting the outdoor unit 2 and the indoor units 3 by refrigerant pipes, and each of the devices constituting the outdoor unit 2 and the indoor units 3, will be described in detail with reference to fig. 2. As described above, the outdoor unit 2 and the indoor unit 3 are connected to each other by the liquid pipe 4 and the air pipe 5 as the refrigerant pipe. Specifically, the closing valve 25 of the outdoor unit 2 and the liquid pipe connection portion 33 of the indoor unit 3 are connected by the liquid pipe 4. The closing valve 26 of the outdoor unit 2 and the air pipe connection portion 34 of the indoor unit 3 are connected by the air pipe 5. As described above, the refrigerant circuit 10 of the air conditioner 1 is constituted.
< Structure of outdoor Unit >
The outdoor unit 2 includes a compressor 21, a four-way valve 22, an outdoor heat exchanger 23, an outdoor fan 27, a closing valve 25 connected to the liquid pipe 4, a closing valve 26 connected to the gas pipe 5, an expansion valve 24, and an outdoor unit control unit 200. The respective devices other than the outdoor fan 27 and the outdoor unit control unit 200 constitute an outdoor unit refrigerant circuit 10a which is a part of the refrigerant circuit 10 by being connected to each other by respective refrigerant pipes described in detail below.
The compressor 21 is a variable displacement compressor whose operation capacity can be changed by controlling the rotation speed by an inverter, not shown. The refrigerant discharge side of the compressor 21 is connected to a port a of the four-way valve 22 via a discharge pipe 61. The refrigerant suction side of the compressor 21 is connected to a port c of the four-way valve 22 via a suction pipe 66.
The four-way valve 22 is a valve for switching the direction of refrigerant flow, and includes four ports a, b, c, and d. As described above, the port a is connected to the refrigerant discharge side of the compressor 21 via the discharge pipe 61. The port b is connected to one refrigerant inlet and outlet of the outdoor heat exchanger 23 via a refrigerant pipe 62. As described above, the port c is connected to the refrigerant suction side of the compressor 21 through the suction pipe 66. The port d is connected to the closing valve 26 through an outdoor air pipe 64.
The outdoor heat exchanger 23 exchanges heat between the refrigerant and outside air taken into the outdoor unit 2 by rotation of an outdoor fan 27, which will be described later. As described above, one refrigerant inlet and outlet of the outdoor heat exchanger 23 is connected to the port b of the four-way valve 22 via the refrigerant pipe 62, and the other refrigerant inlet and outlet is connected to the closing valve 25 via the outdoor-unit liquid pipe 63.
The expansion valve 24 is, for example, an electronic expansion valve. The expansion valve 24 adjusts the opening degree thereof in accordance with the cooling capacity and the heating capacity requested by the indoor unit 3, thereby adjusting the amount of refrigerant flowing to the indoor unit 3.
The outdoor fan 27 is made of a resin material and is disposed in the vicinity of the outdoor heat exchanger 23. The outdoor fan 27 is rotated by a fan motor, not shown, to take in outside air from a suction port, not shown, of the outdoor unit 2 into the outdoor unit 2, and to discharge outside air having exchanged heat with the refrigerant in the outdoor heat exchanger 23 from a discharge port, not shown, of the outdoor unit 2 to the outside of the outdoor unit 2.
In addition to the above-described devices, the outdoor unit 2 is provided with three sensors described below. As shown in fig. 1 (a), the discharge pipe 61 is provided with a discharge temperature sensor 71 that detects the temperature of the refrigerant discharged from the compressor 21. An outdoor heat exchange temperature sensor 72 for detecting the temperature of the outdoor heat exchanger 23 (hereinafter referred to as an outdoor heat exchange temperature) is provided in a substantially middle portion of a refrigerant passage, not shown, of the outdoor heat exchanger 23. Further, an outside air temperature sensor 73 that detects the temperature of outside air flowing into the outdoor unit 2, that is, the outside air temperature, is provided near the suction port, not shown, of the outdoor unit 2.
The outdoor unit control unit 200 is mounted on a control board stored in an unillustrated electrical component box of the outdoor unit 2. As shown in fig. 2 (B), the outdoor unit control unit 200 includes a CPU210, a storage unit 220, a communication unit 230, and a sensor input unit 240.
The storage unit 220 is configured by a ROM or a RAM, and stores a control program from the outdoor unit 2, detection values corresponding to detection signals from various sensors, control states of the compressor 21 and the outdoor fan 27, and the like. The communication unit 230 is an interface for performing communication with the indoor unit 3. The sensor input unit 240 takes in detection results of various sensors of the outdoor unit 2 and outputs the detection results to the CPU 210.
The CPU210 takes in the detection results of the sensors of the outdoor unit 2 via the sensor input unit 240. Further, the CPU210 acquires a control signal transmitted from the indoor unit 3 via the communication unit 230. The CPU210 controls the driving of the compressor 21 and the outdoor fan 27 based on the acquired detection result and the control signal. Further, the CPU210 performs switching control of the four-way valve 22 based on the acquired detection result and the control signal. Further, the CPU210 adjusts the opening degree of the expansion valve 24 based on the acquired detection result and the control signal.
< construction of indoor Unit >
The indoor unit 3 includes a liquid pipe connection part 33 to which the liquid pipe 4 is connected, an air pipe connection part 34 to which the air pipe 5 is connected, and an indoor unit control unit 300, in addition to the indoor heat exchanger 31, the indoor fan 32, the up-down wind direction plate 35, the left-right wind direction plate 36, and the filter 38 described above. The respective devices other than the indoor fan 32, the up-down wind direction plate 35, the left-right wind direction plate 36, the filter 38, and the indoor unit control unit 300 constitute an indoor unit refrigerant circuit 10b that is a part of the refrigerant circuit 10 by being connected to each other by respective refrigerant pipes described in detail below.
The indoor heat exchanger 31 exchanges heat between the refrigerant and the indoor air taken into the indoor unit 3 from the suction port 30f of the indoor unit 3 by the rotation of the indoor fan 32, and one refrigerant inlet/outlet is connected to the liquid pipe connection portion 33 through the indoor unit liquid pipe 67, and the other refrigerant inlet/outlet is connected to the air pipe connection portion 34 through the indoor unit air pipe 68. The indoor heat exchanger 31 functions as an evaporator when the indoor unit 3 performs a cooling operation, and functions as a condenser when the indoor unit 3 performs a heating operation. The liquid pipe connection 33 and the gas pipe connection 34 are connected to each other by welding, a flare nut, or the like.
The indoor fan 32 is made of a resin material and is disposed downstream of the indoor heat exchanger 31 in the ventilation path 30h as described above. The indoor fan 32 is rotated by a fan motor, not shown, to take in indoor air into the indoor unit 3 from the suction port 30f of the indoor unit 3 and blow out the indoor air having exchanged heat with the refrigerant in the indoor heat exchanger 31 into the room from the discharge port 30g of the indoor unit 3.
In addition to the above-described devices, the indoor unit 3 is provided with two sensors described below. An indoor heat exchange temperature sensor 74 that detects the temperature of the indoor heat exchanger 31 (hereinafter referred to as an indoor heat exchange temperature) is provided in a substantially middle portion of a refrigerant path, not shown, of the indoor heat exchanger 31. As shown in fig. 1 (B), an indoor temperature sensor 75 for detecting the temperature of air sucked into the indoor unit 3 through the suction port 30f, that is, the indoor temperature is provided between the suction port 30f of the indoor unit 3 and the filter 38.
The indoor unit control unit 300 is mounted on a control board stored in an unillustrated electrical component box of the indoor unit 3. As shown in fig. 2 (B), the indoor unit control unit 300 includes a CPU310, a storage unit 320, a communication unit 330, and a sensor input unit 340.
The storage unit 320 is configured by a ROM or a RAM, and stores a control program from the indoor unit 3, detection values corresponding to detection signals from various sensors, a control state of the indoor fan 32, and the like. The communication unit 330 is an interface for performing communication with the outdoor unit control unit 200 of the outdoor unit 2. The sensor input unit 340 takes in the detection results of the indoor heat exchange temperature sensor 74 and the indoor temperature sensor 75 of the indoor unit 3 and outputs the results to the CPU 110.
The CPU310 takes in the detection results of the sensors of the indoor unit 3 via the sensor input unit 340. The CPU310 also takes in an operation information signal including an operation mode (cooling operation/heating operation) and an air volume transmitted from a remote controller not shown operated by the user via the communication unit 330. The CPU310 controls the driving of the indoor fan 32, the up-down wind direction plate 35, and the left-right wind direction plate 36 based on the acquired detection result and the operation information signal.
< operation of refrigerant Circuit >
Next, the flow of the refrigerant in the refrigerant circuit 10 and the operation of each part during the air-conditioning operation of the air-conditioning apparatus 1 according to the present embodiment will be described with reference to fig. 2 (a). In the following description, first, a case where the indoor unit 3 performs a cooling operation will be described, and then, a case where the indoor unit 3 performs a heating operation will be described. In fig. 2 (a), solid arrows indicate the flow of the refrigerant during the cooling operation, and broken arrows indicate the flow of the refrigerant during the heating operation.
< Cooling operation >
When the indoor unit 3 performs the cooling operation, as shown in fig. 2 (a), the four-way valve 22 is switched to the state shown by the solid line, that is, the port a and the port b of the four-way valve 22 are communicated, or the port c and the port d are communicated. Thus, in the refrigerant circuit 10, the outdoor heat exchanger 23 functions as a condenser, the indoor heat exchanger 31 functions as an evaporator, and the refrigerant circuit 10 serves as a refrigeration cycle in which the refrigerant circulates in the direction indicated by the solid arrow.
In the state of the refrigerant circuit 10 as described above, the high-pressure refrigerant discharged from the compressor 21 flows through the discharge pipe 61 into the four-way valve 22, flows from the four-way valve 22 into the refrigerant pipe 62, and flows into the outdoor heat exchanger 23. The refrigerant flowing into the outdoor heat exchanger 23 exchanges heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 27, and is condensed. The refrigerant flowing out of the outdoor heat exchanger 23 to the outdoor-unit liquid pipe 63 is decompressed when passing through the expansion valve 24 having an opening degree corresponding to the cooling capacity requested by the user in the indoor unit 3, and flows into the liquid pipe 4 through the closing valve 25.
The refrigerant flowing through the liquid pipe 4 and flowing into the indoor unit 3 via the liquid pipe connection portion 33 flows through the indoor unit liquid pipe 67 and flows into the indoor heat exchanger 31, exchanges heat with the indoor air taken into the air passage 30h of the indoor unit 3 from the suction port 30f by the rotation of the indoor fan 32, and evaporates. In this way, the indoor heat exchanger 31 functions as an evaporator, and the indoor air having exchanged heat with the refrigerant in the indoor heat exchanger 31 is blown out into the room from the air outlet 30g, thereby cooling the room in which the indoor unit 3 is installed.
The refrigerant flowing out of the indoor heat exchanger 31 flows through the indoor air pipe 68 and flows into the air pipe 5 via the air pipe connecting portion 34. The refrigerant flowing through the air pipe 5 and flowing into the outdoor unit 2 via the closing valve 26 flows through the outdoor unit air pipe 64, the four-way valve 22, and the suction pipe 66 in this order, is sucked into the compressor 21, and is compressed again.
< heating operation >
When the indoor unit 3 performs the heating operation, as shown in fig. 2 (a), the four-way valve 22 is switched to the state shown by the broken line, that is, the port a and the port d of the four-way valve 22 are communicated, or the port b and the port c are communicated. Thus, in the refrigerant circuit 10, the outdoor heat exchanger 23 functions as an evaporator, the indoor heat exchanger 31 functions as a condenser, and the refrigerant circuit 10 serves as a heating cycle in which the refrigerant circulates in the direction indicated by the broken-line arrow.
In the state of the refrigerant circuit 10 as described above, the high-pressure refrigerant discharged from the compressor 21 flows through the discharge pipe 61 and into the four-way valve 22, flows from the four-way valve 22 into the outdoor-unit air pipe 64, and flows into the air pipe 5 via the blocking valve 26. The refrigerant flowing through the gas pipe 5 flows into the indoor unit 3 via the gas pipe connection 34.
The refrigerant flowing into the indoor unit 3 flows through the indoor unit air pipe 68 and flows into the indoor heat exchanger 31, exchanges heat with the indoor air taken into the ventilation path 30h of the indoor unit 3 from the suction port 30f by the rotation of the indoor fan 32, and condenses. In this way, the indoor heat exchanger 31 functions as a condenser, and the indoor air having exchanged heat with the refrigerant in the indoor heat exchanger 31 is blown out into the room from the air outlet 30g, whereby the room in which the indoor unit 3 is installed is heated.
The refrigerant flowing out of the indoor heat exchanger 31 flows through the indoor unit liquid pipe 67 and flows into the liquid pipe 4 via the liquid pipe connecting portion 33. The refrigerant flowing through the liquid pipe 4 and flowing into the outdoor unit 2 via the closing valve 25 flows through the outdoor unit liquid pipe 63 and is decompressed when passing through the expansion valve 24 having an opening degree corresponding to the heating capacity requested by the user in the indoor unit 3.
The refrigerant passing through the expansion valve 24 and flowing into the outdoor heat exchanger 23 exchanges heat with the outside air taken into the outdoor unit 2 by the rotation of the outdoor fan 27, and evaporates. The refrigerant flowing out of the outdoor heat exchanger 23 into the refrigerant pipe 62 flows through the four-way valve 22 and the suction pipe 66, is sucked into the compressor 21, and is compressed again.
< control of driving of compressor, outdoor fan, and indoor fan during heating operation >
Next, the driving control of the compressor 21, the outdoor fan 27, and the indoor fan 32 during the heating operation (hereinafter referred to as heating operation control) will be described in detail with reference to the flowchart shown in fig. 3. In fig. 3, ST denotes a step of processing, and the following numerals denote step numbers.
The outdoor unit control unit 200 and the indoor unit control unit 300 described above constitute a control unit of the present invention. Therefore, in the following description of the control and processing including fig. 3, the control unit will be described as the control main body of the air conditioner 1, and the control main bodies of the respective outdoor unit 2 and indoor unit 3 will be described by appropriately using (the CPU210 of) the outdoor unit control unit 200 and (the CPU310 of) the indoor unit control unit 300.
If an instruction to start the heating operation is given by a user, the control unit takes in the indoor temperature (hereinafter, referred to as indoor temperature Ti) and reads out the set temperature (hereinafter, referred to as set temperature Tp) (ST 1). Specifically, the CPU310 of the indoor unit control unit 300 periodically (for example, every 30 seconds) takes in the indoor temperature Ti detected by the sensor input unit 340 via the sensor input unit 340. CPU310 reads out a set temperature Tp set by a user operating a remote controller, not shown, and stored in storage unit 320.
Next, the control means calculates a temperature difference (hereinafter referred to as temperature difference Δ T) between the set temperature Tp read in ST1 and the acquired room temperature Ti (ST 2). Specifically, CPU310 subtracts indoor temperature Ti from set temperature Tp to calculate temperature difference Δ T.
Next, the control means drives the compressor 21 at the rotation speed of the compressor 21 (hereinafter referred to as the compressor rotation speed Rc) corresponding to the temperature difference Δ T calculated in ST 2(ST 3). Specifically, the CPU310 transmits the compressor rotation speed Rc corresponding to the calculated temperature difference Δ T to the outdoor unit 2 via the communication unit 330. The CPU210 of the outdoor unit control unit 200 that has received the compressor rotation speed Rc transmitted from the indoor unit 3 via the communication unit 230 drives the compressor 21 at the received compressor rotation speed Rc.
Next, the control means sets the opening degree of the expansion valve 24 (hereinafter referred to as the expansion valve opening degree D) to an opening degree corresponding to the heating capacity requested by the user in the indoor unit 3(ST 4). Specifically, the CPU310 adjusts the expansion valve opening degree D so that the discharge temperature of the compressor 21 detected by the discharge temperature sensor 71 during the heating operation becomes a predetermined target temperature.
Next, the control means drives the outdoor fan 27 at the rotation speed of the outdoor fan 27 (hereinafter referred to as outdoor fan rotation speed Rfo) corresponding to the compressor rotation speed Rc determined in ST 3(ST 5). Specifically, the CPU210 drives the outdoor fan 27 at an outdoor fan rotation speed Rfo corresponding to the compressor rotation speed Rc.
Next, the control unit determines whether or not the air volume of the conditioned air blown out from the air outlet 30g of the indoor unit 3 is set to automatic by the user (ST 6). If the air volume is set to automatic (ST 6-Yes), the control unit drives the indoor fan 32 at the rotation speed of the indoor fan 32 (hereinafter referred to as indoor fan rotation speed Rfi) corresponding to the temperature difference Δ T calculated in ST 2(ST 7). In addition, if the air volume is not set to automatic (ST 6-No), the control unit drives the indoor fan 32 at an indoor fan rotation speed Rfi corresponding to the air volume set by the user (ST 8). Specifically, the CPU310 drives the indoor fan 32 at an indoor fan rotation speed Rfi corresponding to either the temperature difference Δ T or the air volume set by the user.
Next, the control unit controls the up-down wind deflector 35 and the left-right wind deflector 36 to have the wind direction set by the user (ST9), and returns the process to ST 1. Specifically, if the user's setting is "swing", the CPU310 automatically rotates the up-down wind direction plate 35 up and down, and the left-right wind direction plate 36 left and right. Further, if the user's setting is a predetermined position, the up-down wind direction plate 35 and the left-right wind direction plate 36 are rotated so as to be positioned at the position set by the user.
< protection control during heating operation >
Next, a heating operation time protection control in which the discharge pressure of the compressor 21 does not exceed the upper limit value of the use range during the heating operation will be described with reference to fig. 4. In fig. 4, ST denotes a step of processing, and the following numerals denote step numbers.
First, the control unit takes in the temperature of the indoor heat exchanger 31 (hereinafter referred to as the indoor heat exchange temperature Tc) and the discharge temperature of the compressor 21 (hereinafter referred to as the discharge temperature Td) (ST 11). Specifically, the CPU310 periodically (for example, every 30 seconds) takes in the indoor heat exchange temperature Tc detected by the indoor heat exchange temperature sensor 74 via the sensor input unit 340. On the other hand, the CPU210 periodically (for example, every 30 seconds) takes in the discharge temperature Td detected by the discharge temperature sensor 71 via the sensor input unit 240.
Next, the control unit determines whether or not the indoor heat exchange temperature Tc taken in at ST11 is higher than a predetermined temperature (hereinafter referred to as a first threshold indoor heat exchange temperature Tch1) (ST 12). Specifically, the CPU310 reads the first threshold indoor heat exchange temperature Tch1 stored in the storage unit 320 in advance, and compares the indoor heat exchange temperature Tch with the indoor heat exchange temperature Tc. Here, the first threshold indoor heat exchange temperature Tch1 is a temperature obtained by a test or the like in advance, and is set to a temperature lower than the indoor heat exchange temperature Tc corresponding to the upper limit of the usage range of the discharge pressure of the compressor 21 by a predetermined temperature, for example, 55 ℃.
If the indoor heat exchange temperature Tc is equal to or higher than the first threshold indoor heat exchange temperature Tch 1(ST 12-Yes), the control unit decreases the rotational speed of the compressor 21 by a predetermined compressor release rotational speed (hereinafter referred to as a compressor release rotational speed Rcr) at predetermined compressor release interval times (hereinafter referred to as compressor release interval times Tc) (ST 16). Specifically, the CPU310 transmits a signal for determining that the indoor heat exchange temperature Tc is higher than the first threshold indoor heat exchange temperature Tch1 to the outdoor unit 2 via the communication unit 330, and the CPU210 receiving the signal via the communication unit 230 controls the compressor 21 so as to reduce the compressor release rotational speed Rcr from the current compressor rotational speed Rc every compressor release interval time Tc. Here, the compressor release interval time Tc and the compressor release rotational speed Rcr are values for which the effect of reducing the indoor heat exchange temperature Tc is confirmed by performing a test or the like in advance, and for example, the compressor release interval time Tc is 60 seconds and the compressor release rotational speed Rcr is 2 rps.
The control unit having finished the process of ST16 takes in the indoor heat exchange temperature Tc (ST17), and determines whether or not the taken-in indoor heat exchange temperature Tc is equal to or higher than the first threshold indoor heat exchange temperature Tch 1(ST 18). Specifically, the CPU310 takes in the indoor heat exchange temperature Tc, and determines whether or not the taken-in indoor heat exchange temperature Tc is equal to or higher than a first threshold indoor heat exchange temperature Tch 1.
If the taken-in indoor heat exchange temperature Tc is not above the first threshold indoor heat exchange temperature Tch 1(ST 18-No), the control unit returns the process to ST 11. If the taken indoor heat exchange temperature Tc is equal to or higher than the first threshold indoor heat exchange temperature Tch 1(ST 18-Yes), the control unit stops the heating operation (ST19) and ends the protection control during the heating operation. Specifically, if the taken-in indoor heat exchange temperature Tc is equal to or higher than the first threshold indoor heat exchange temperature Tch1, the CPU310 stops the indoor fan 32 and transmits a signal indicating that the taken-in indoor heat exchange temperature Tc is equal to or higher than the first threshold indoor heat exchange temperature Tch1 to the outdoor unit 2 via the communication unit 330. The CPU210 that receives the signal via the communication unit 230 stops the compressor 21 and the outdoor fan 27.
In ST12, if the indoor heat exchange temperature Tc is not equal to or higher than the first threshold indoor heat exchange temperature Tch 1(ST 12-No), the control unit determines whether or not the discharge temperature Td detected in ST11 is equal to or higher than a predetermined first threshold discharge temperature (hereinafter referred to as a first threshold discharge temperature Tdh1) and lower than a predetermined second threshold discharge temperature (hereinafter referred to as a second threshold discharge temperature Tdh2) higher than the first threshold discharge temperature Tdh 1(ST 13). Specifically, the CPU210 periodically (for example, every 30 seconds) acquires the discharge temperature Td detected by the discharge temperature sensor 71 via the sensor input unit 240, and determines whether or not the acquired discharge temperature Td is equal to or higher than the first threshold discharge temperature Tdh1 and lower than the second threshold discharge temperature Tdh2 stored in the storage unit 220.
Here, the first threshold discharge temperature Tdh1 and the second threshold discharge temperature Tdh2 are temperatures obtained by performing an experiment or the like in advance and stored in the storage unit 220, and are temperatures lower than the discharge temperature Td corresponding to the upper limit value of the use range of the discharge pressure of the compressor 21 by a predetermined temperature, and for example, the first threshold discharge temperature Tdh1 is 105 ℃ and the second threshold discharge temperature Tdh2 is 115 ℃.
If the fetched discharge temperature Td is above the first threshold discharge temperature Tdh1 and below the second threshold discharge temperature Tdh2(ST 13-Yes), the control unit decreases the compressor release rotation speed Rcr every time the rotation speed of the compressor 21 is decreased by the compressor release interval time tc (ST15), and returns the process to ST 11. The processing of ST15 is the same as that of ST16, and therefore, detailed description thereof is omitted. In addition, in the processing of ST15 and ST16, when the compressor rotation speed Rc is reduced to the lower limit rotation speed of the use range by reducing the compressor release rotation speed Rcr every time the compressor rotation speed Rc is reduced, the compressor rotation speed Rc is maintained at the lower limit rotation speed when the processing of ST15 and ST16 is subsequently performed.
In ST13, if the fetched discharge temperature Td is not the first threshold discharge temperature Tdh1 or more and is lower than the second threshold discharge temperature Tdh2(ST 13-No), the control unit determines whether the fetched discharge temperature Td is the second threshold discharge temperature Tdh2 or more (ST 14). Specifically, the CPU210 determines whether or not the acquired discharge temperature Td is equal to or higher than a second threshold discharge temperature Tdh 2.
If the taken-in discharge temperature Td is the second threshold discharge temperature Tdh2 or higher (ST 14-Yes), the control unit advances the process to ST 19. If the fetched discharge temperature Td is not above the second threshold discharge temperature Tdh2(ST 14-No), that is, if the fetched discharge temperature Td is lower than the first threshold discharge temperature Tdh1, the control unit returns the process to ST 11.
< indoor Heat exchange heating operation >
Next, the indoor heat exchange heating operation of the present invention will be described with reference to fig. 5 to 11. Here, the indoor heat exchange heating operation is an operation performed for the same purpose as that in the heating operation, and the temperature of the indoor heat exchanger 31 is raised to a temperature higher than the temperature (about 40 ℃) in the heating operation to kill mold and bacteria and reduce the number of mold and bacteria. In the present embodiment, a button for instructing the start of the indoor heat exchange heating operation is provided on a remote controller, not shown, for operating the indoor unit 3, and the indoor heat exchange heating operation is executed as long as the user operates the button. Further, the indoor heat exchange heating operation may be performed at an optimum timing determined by the air conditioner 1, such as when the indoor unit 3 is provided with a human body detection sensor and the indoor heat exchange heating operation is performed when the human body detection sensor detects that the user is not present in the room.
The applicant has found through experiments that the number of mold and bacteria can be greatly reduced by maintaining the indoor heat exchange temperature Tc at 55 ℃ or higher for 10 minutes when the indoor heat exchange heating operation is performed. The obtained findings will be described below with reference to fig. 5.
Fig. 5 is a graph showing the temporal change in the number of mold and bacteria when the indoor heat exchange temperature Tc is maintained at a constant temperature in a state where dew condensation water is present in the indoor heat exchanger 31. Fig. 5 (a) is a graph showing a mold (hereinafter referred to as "mold") which is a kind of mold (black mold) appearing dark. The horizontal axis of the graph of fig. 5 a represents the heating time (unit: min) as the time for maintaining the indoor heat exchange temperature Tc at 40 ℃, 45 ℃ and 50 ℃, and the vertical axis represents the residual ratio of mold (residual ratio of mold in fig. 5 a:%) assuming that the number of mold (number of mold colonies) when the heating time is 0 min (before heating) is 100.
When the indoor heat exchange temperature Tc was set to 40 ℃ as shown in fig. 5 (a), the number of mold was almost unchanged even when the heating time reached 10 minutes, and the mold remaining rate after 10 minutes was almost 100%. On the other hand, when the indoor heat exchange temperature Tc is 45 ℃ or 50 ℃, the mold survival rate is less than 10% at any indoor heat exchange temperature Tc when the heating time reaches 5 minutes. In particular, when the indoor heat exchange temperature Tc is set to 50 ℃, the mold remaining rate at the time when the heating time reaches 5 minutes is less than 1%, and the number of molds is greatly reduced in a short time.
On the other hand, fig. 5 (B) is a graph about coliform, which is one of bacteria. The horizontal axis of the graph of fig. 5 (B) represents the heating time (unit: min) corresponding to the time for maintaining the indoor heat exchange temperature Tc at 40 ℃, 45 ℃, 50 ℃, and 55 ℃, and the vertical axis represents the residual rate of coliform bacteria (residual rate of bacteria in fig. 5 (B):%) corresponding to 100 counts of coliform bacteria having 0 min (before heating) heating time.
When the indoor heat exchange temperature Tc is lower than 50 ℃ as shown in fig. 5 (B), the residual ratio of bacteria is not lower than 50% even when the heating time is 10 minutes, and it cannot be said that the number of bacteria is significantly reduced. On the other hand, when the indoor heat exchange temperature Tc is 55 ℃, the bacteria remaining rate is less than 10% when the heating time reaches 4 minutes, is approximately 1% when the heating time reaches 5 minutes, and is less than 1% when the heating time is further extended to 10 minutes. That is, the number of bacteria can be greatly reduced by maintaining the indoor heat exchange temperature Tc at 55 ℃ for 10 minutes.
As seen from the graphs of fig. 5 described above, in order to significantly reduce the remaining rate of mold and bacteria in the indoor heat exchanger 31, it is preferable that the indoor heat exchange temperature Tc is 55 ℃ or higher and this state is continued for 10 minutes in a state where dew condensation water is present in the indoor heat exchanger 31, for example, in a state where dew condensation water generated in the indoor heat exchanger 31 during the cooling operation of the air conditioner 1 remains after the end of the cooling operation. This is because the entire surface of the mold and bacteria is covered with dew condensation water, and thus more heat acts on the mold and bacteria from the dew condensation water than does not act on the mold and bacteria from the surface of the indoor heat exchanger 31 alone.
In addition, even if the drying operation is performed in which the indoor fan 32 is driven to pass air through the indoor heat exchanger 31 and evaporate dew condensation water generated in the indoor heat exchanger 31 during the cooling operation of the air conditioner 1, the portions of the indoor heat exchanger 31 near the V-shaped bent portions 30n and the drain pan 30m where air is difficult to pass cannot be dried. In this way, even in the portion where the dew condensation water stays for a long time without being dried, if the indoor heat exchange heating operation of the present embodiment is performed, the dew condensation water staying in the portion where the air hardly passes can be 55 ℃ or higher, and therefore, the remaining rate of mold and bacteria growing in these portions can be greatly reduced.
< indoor Fan control Table and outdoor Fan control Table >
Next, a table showing the control of the indoor fan 32 and the control of the outdoor fan 27 used in the indoor heat exchange heating operation, which are used in the indoor heat exchange heating operation, will be described with reference to fig. 6.
< indoor Fan control Table >
First, an indoor fan control table 400 shown in fig. 6 (a) will be described. The indoor fan control table 400 is obtained by performing a test or the like in advance, and is stored in the storage unit 320 of the indoor unit control unit 300. As is well known, when the indoor heat exchanger 31 functions as a condenser during the indoor heat exchange heating operation, the indoor fan control table 400 controls the indoor fan 32 based on the indoor fan control table 400 so that the indoor heat exchange temperature Tc is maintained in the range of 55 to 57 ℃.
In the indoor fan control table 400, the indoor fan rotation speed Rfi (unit: rpm) is determined from the indoor heat exchange temperature Tc (unit: c) and each time when the indoor heat exchange temperature Tc rises/maintains/falls. Here, the case where the indoor heat exchange temperature Tc is increased ("Tc increase case" in fig. 6 a) refers to a case where two indoor heat exchange temperatures Tc detected at different time intervals are used, and the indoor heat exchange temperature Tc detected later is higher than the indoor heat exchange temperature Tc detected earlier. The case where the indoor heat exchange temperature Tc is maintained (the case of "Tc maintenance" in fig. 6 a) means a case where the previously detected indoor heat exchange temperature Tc and the subsequently detected indoor heat exchange temperature Tc are the same. The case where the indoor heat exchange temperature Tc is decreased ("Tc decrease case" in fig. 6A) is a case where two indoor heat exchange temperatures Tc detected at different time intervals are used, and the indoor heat exchange temperature Tc detected later is lower than the indoor heat exchange temperature Tc detected earlier.
Specifically, the indoor fan rotation speed Rfi at "Tc-up" is set to a rotation speed obtained by adding 70rpm to the current indoor fan rotation speed Rfi when the indoor heat exchange temperature Tc is 57 ℃. When the indoor heat exchange temperature Tc is 55 ℃ or higher and lower than 57 ℃, the current indoor fan rotation speed Rfi is not changed. When the indoor heat exchange temperature Tc is not less than 53 ℃ and less than 55 ℃ and when the indoor heat exchange temperature Tc is less than 53 ℃, the rotation speed is set to a value obtained by subtracting 10rpm from the current indoor fan rotation speed Rfi.
When the indoor heat exchange temperature Tc is detected (for example, every 30 seconds), the indoor fan rotation speed Rfi decreases by 10rpm when the indoor heat exchange temperature Tc is lower than 53 ℃ when the indoor heat exchange temperature Tc rises or when the indoor heat exchange temperature Tc is not lower than 53 ℃ and lower than 55 ℃. This reduces the amount of air flowing through the indoor heat exchanger 31, and the indoor heat exchange temperature Tc rapidly reaches 55 ℃.
When the indoor heat exchange temperature Tc is 55 ℃ or higher and lower than 57 ℃ when the indoor heat exchange temperature Tc is increased, the indoor fan rotation speed Rfi is not changed. Thus, the amount of air flowing through the indoor heat exchanger 31 does not change, and the indoor heat exchange temperature Tc is maintained in the range of 55 ℃ or higher and lower than 57 ℃. When the indoor heat exchange temperature Tc is 57 ℃ or higher, the indoor fan rotation speed Rfi is increased by 70rpm each time to increase the amount of air flowing into the indoor heat exchanger 31, so that the indoor heat exchange temperature Tc does not reach 59 ℃ or higher.
Next, when the indoor heat exchange temperature Tc is 57 ℃ or higher, the indoor fan rotation speed Rfi at "Tc maintenance" is set to a rotation speed obtained by adding 50rpm to the current indoor fan rotation speed Rfi. When the indoor heat exchange temperature Tc is 55 ℃ or higher and lower than 57 ℃, the current indoor fan rotation speed Rfi is not changed. When the indoor heat exchange temperature Tc is 53 ℃ or higher and lower than 55 ℃, the rotation speed is set to a value obtained by subtracting 30rpm from the current indoor fan rotation speed Rfi. In the case where the indoor heat exchange temperature Tc is lower than 53 ℃, the rotation speed obtained by subtracting 40rpm from the current indoor fan rotation speed Rfi is set.
In the case where the indoor heat exchange temperature Tc is lower than 53 ℃ while the indoor heat exchange temperature Tc is not changed, the indoor fan rotation speed Rfi is lowered by 40rpm each time the indoor heat exchange temperature Tc is detected (for example, every 30 seconds). In addition, when the indoor heat exchange temperature Tc is 53 ℃ or more and less than 55 ℃, the indoor fan rotation speed Rfi is reduced by 30rpm each time the indoor heat exchange temperature Tc is detected. This reduces the amount of air flowing through the indoor heat exchanger 31, and the indoor heat exchange temperature Tc rapidly reaches 55 ℃. Further, it is considered that the "Tc maintaining time" is a state in which the indoor heat exchange temperature Tc is less likely to increase than the "Tc increasing time", and therefore, the rotation speed decreased from the indoor fan rotation speed Rfi is increased so that the indoor fan rotation speed Rfi becomes lower than the "Tc increasing time" even at the same indoor heat exchange temperature Tc.
When the indoor heat exchange temperature Tc is 55 ℃ or higher but lower than 57 ℃ without change, the indoor fan rotation speed Rfi is not changed. Thus, the indoor heat exchange temperature Tc is maintained in the range of 55 ℃ or higher and lower than 57 ℃ without changing the amount of air flowing through the indoor heat exchanger 31. When the indoor heat exchange temperature Tc is 57 ℃ or higher, the indoor fan rotation speed Rfi is increased by 50rpm every time the amount of air flowing through the indoor heat exchanger 31 is increased, so that the indoor heat exchange temperature Tc does not reach 59 ℃ or higher. Further, since the "Tc maintaining time" is considered to be a state in which the indoor heat exchange temperature Tc is less likely to increase than the "Tc increasing time", the rotation speed added to the indoor fan rotation speed Rfi is reduced so that the indoor fan rotation speed Rfi becomes lower than the "Tc increasing time" even at the same indoor heat exchange temperature Tc.
In addition, the indoor fan rotation speed Rfi at "Tc down" does not change the current indoor fan rotation speed Rfi when the indoor heat exchange temperature Tc is 57 ℃ or higher and when the indoor heat exchange temperature Tc is 55 ℃ or higher and lower than 57 ℃. When the indoor heat exchange temperature Tc is not less than 53 ℃ and less than 55 ℃ and when the indoor heat exchange temperature Tc is less than 53 ℃, the rotation speed is set to a value obtained by subtracting 40rpm from the current indoor fan rotation speed Rfi.
When the indoor heat exchange temperature Tc is lower than 53 ℃ or when the indoor heat exchange temperature Tc is not lower than 53 ℃ and lower than 55 ℃ when the indoor heat exchange temperature Tc is lowered, the indoor fan rotation speed Rfi is lowered by 40rpm every time the indoor heat exchange temperature Tc is detected (for example, every 30 seconds), thereby reducing the amount of air flowing through the indoor heat exchanger 31. This reduces the amount of air flowing through the indoor heat exchanger 31, and allows the indoor heat exchange temperature Tc to quickly reach 55 ℃ or higher. Since "when Tc is decreased" is in a state where the indoor heat exchange temperature Tc is decreased, the rotation speed subtracted from the indoor fan rotation speed Rfi is increased so that the indoor fan rotation speed Rfi is further decreased than when "Tc is maintained" even for the same indoor heat exchange temperature Tc.
When the indoor heat exchange temperature Tc is 55 ℃ or more and less than 57 ℃ or when the indoor heat exchange temperature Tc is 57 ℃ or more when the indoor heat exchange temperature Tc is decreased, the indoor fan rotation speed Rfi is not changed. Thus, the indoor heat exchange temperature Tc is maintained in the range of 55 ℃ or higher and lower than 57 ℃ without changing the amount of air flowing through the indoor heat exchanger 31. Further, it is considered that the indoor heat exchange temperature Tc is less likely to increase when the Tc is decreased than when the Tc is maintained, and therefore, even if the indoor fan rotation speed Rfi is not changed when the indoor heat exchange temperature Tc is 55 ℃ or higher, the indoor heat exchange temperature Tc does not reach 59 ℃ or higher.
When the indoor fan rotation speed Rfi is increased or decreased using the indoor fan control table 400 described above, the indoor fan rotation speed Rfi is increased or decreased between the upper limit rotation speed and the lower limit rotation speed (corresponding to the indoor fan minimum rotation speed Rfim described later) of the indoor fan rotation speed Rfi. Here, the upper limit rotation speed is, for example, 900rpm, and the lower limit rotation speed is, for example, 300 rpm. If the indoor fan rotation speed Rfi is increased every time by the rotation speed determined by the indoor fan control table 400 and reaches 900rpm, the indoor fan rotation speed Rfi is maintained at 900rpm even in the case where the indoor fan rotation speed Rfi is increased later. In addition, if the indoor fan rotation speed Rfi is lowered by the rotation speed determined by the indoor fan control table 400 every time and reaches 300rpm, the indoor fan rotation speed Rfi is maintained at 300rpm even in the case where the indoor fan rotation speed Rfi is lowered later.
Further, 300rpm, which is the lower limit rotation speed in the indoor heat exchange heating operation, is set to a rotation speed lower than the lower limit rotation speed (for example, 420rpm) of the indoor fan 32 in the heating operation. This is because, in the indoor heat exchange heating operation, the rotation speed of the indoor fan 32 is reduced as much as possible to reduce the amount of air flowing through the indoor heat exchanger 31, thereby rapidly increasing the indoor heat exchange temperature Tc.
< outdoor Fan control Table >
Next, an outdoor fan control table 500 shown in fig. 6 (B) will be described. The outdoor fan control table 500 is obtained by performing a test or the like in advance, and is stored in the storage unit 220 of the outdoor unit control unit 200. As is well known, in the outdoor fan control table 500, when the indoor fan 32 is controlled based on the indoor fan control table 400 so as to maintain the indoor heat exchange temperature Tc at 55 to 57 ℃ during the indoor heat exchange heating operation, the discharge pressure of the compressor 21 can be made not to exceed the upper limit value of the use range by controlling the outdoor fan 27 based on the outdoor fan control table 500.
In the outdoor fan control table 500, the rotational speed of the outdoor fan (unit: rpm, hereinafter, referred To as outdoor fan rotational speed Rfo) is determined based on the outside air temperature (unit: C. hereinafter, referred To as outside air temperature To) and the indoor temperature Ti (unit: C.) detected by the outside air temperature sensor 73. Specifically, when the outside air temperature To is 24 ℃ or higher, the outdoor fan rotation speed Rfo is 0rpm regardless of the indoor temperature Ti. In addition, when the outside air temperature To is 16 ℃ or higher and lower than 24 ℃, the outdoor fan rotation speed Rfo is 0rpm if the indoor temperature Ti is 27 ℃ or higher, and 190rpm if the indoor temperature Ti is lower than 27 ℃. When the outside air temperature To is lower than 16 ℃, the outdoor fan rotation speed Rfo is set To the same control as that in the heating operation, that is, the rotation speed corresponding To the compressor rotation speed Rc.
When the outside air temperature To is 24 ℃ or higher, the evaporation pressure of the outdoor heat exchanger 23 functioning as an evaporator during the indoor heat exchange heating operation becomes higher than when the outside air temperature To is lower than 24 ℃. When the evaporation pressure becomes high, the condensation pressure of the indoor heat exchanger 31 functioning as a condenser also becomes high, and therefore, the discharge pressure of the compressor 21 becomes high, and there is a possibility that the discharge pressure exceeds the upper limit value of the usage range. Therefore, when the outside air temperature To is 24 ℃ or higher, the outdoor fan rotation speed Rfo is set To 0rpm, that is, stopped regardless of the indoor temperature Ti, so that the evaporation capacity of the outdoor heat exchanger 23 is reduced so as not To increase the evaporation pressure.
When the outside air temperature To is 16 ℃ or higher and lower than 24 ℃ and the indoor temperature Ti is 27 ℃ or higher, the condensation capacity of the indoor heat exchanger 31 functioning as a condenser is reduced and the condensation pressure is increased, as compared with the case where the indoor temperature Ti is lower than 27 ℃. At this time, if the outdoor fan 27 is driven to increase the evaporation capacity and the evaporation pressure in the outdoor heat exchanger 23, the originally increased condensation pressure becomes higher, and therefore, the discharge pressure of the compressor 21 also increases, and may exceed the upper limit of the usage range. Therefore, even when the outside air temperature To is 16 ℃ or higher and lower than 24 ℃ and the indoor temperature Ti is 27 ℃ or higher, the evaporation capacity of the outdoor heat exchanger 23 is reduced so as not To increase the evaporation pressure by stopping the outdoor fan rotation speed Rfo at 0 rpm.
On the other hand, in the case where the outside air temperature To is 16 ℃ or higher and lower than 24 ℃ and the indoor temperature Ti is lower than 27 ℃, the discharge pressure of the compressor 21 is less likely To exceed the upper limit of the usage range even if the outdoor fan 27 is driven because the condensation pressure is lower than in the case where the indoor temperature Ti is 27 ℃ or higher. Therefore, when the outdoor air temperature To is 16 ℃ or higher and lower than 24 ℃ and the indoor temperature Ti is lower than 27 ℃, the outdoor fan rotation speed Rfo is driven at a rotation speed at which the discharge pressure of the compressor 21 does not exceed the upper limit value of the usage range due To the increase in the evaporation pressure, for example, 190rpm which is the rotation speed in the present embodiment. This prevents an excessive increase in the discharge pressure of the compressor 21, and increases the evaporation pressure in the outdoor heat exchanger 23, thereby rapidly increasing the indoor heat exchange temperature Tc, which is the condensation temperature in the indoor heat exchanger 31.
In the indoor heat exchange heating operation, 190rpm, which is the outdoor fan speed Rfo when the outdoor air temperature To is 16 ℃ or higher and lower than 24 ℃ and the indoor temperature Ti is lower than 27 ℃, is set To a speed lower than the lower limit speed (e.g., 500rpm) of the outdoor fan 27 in the heating operation. This is because, in the indoor heat exchange heating operation, the discharge pressure of the compressor 21 is likely to exceed the upper limit value of the usage range because the indoor heat exchange temperature Tc is increased to a temperature higher than that in the heating operation, and the amount of air flowing through the outdoor heat exchanger 23 functioning as an evaporator in the indoor heat exchange heating operation is reduced as compared to that in the heating operation, so that the increase in the evaporation pressure in the outdoor heat exchanger 23 is suppressed, and the discharge pressure of the compressor 21 is suppressed from excessively increasing.
In the case where the outside air temperature To is lower than 16 ℃, the evaporation pressure in the outdoor heat exchanger 23 is less likely To rise even if the outdoor fan 27 is driven, as compared with the case where the outside air temperature To is 16 ℃ or higher. Therefore, when the outside air temperature To is lower than 16 ℃, the outdoor fan rotation speed Rfo is set To the same control as that in the heating operation, that is, the rotation speed corresponding To the compressor rotation speed Rc, regardless of the indoor temperature Ti. Thereby, the evaporation pressure in the outdoor heat exchanger 23 is increased, and the indoor heat exchange temperature Tc, which is the condensation temperature in the indoor heat exchanger 31, is rapidly increased.
< control of indoor Heat exchange heating operation >
Next, the flow of processing related to the indoor heat exchange heating operation will be described with reference to fig. 7 to 10. Fig. 7 is a main routine of processing performed by the control unit of the air conditioner 1 during the indoor heat exchange heating operation. Fig. 8 is a subroutine of the processing performed by the control unit during the indoor heat exchange heating operation, and shows a flow of the processing related to the pre-heating operation control performed for the purpose of suppressing the generation of dew condensation water in the indoor unit 3 before the indoor heat exchanger 31 is heated.
Fig. 9 is a subroutine of the process performed by the control unit during the indoor heat exchange heating operation, and shows a flow of the process related to the temperature maintaining indoor fan control performed for the purpose of maintaining the indoor heat exchange temperature Tc in the range of 55 to 57 ℃ using the indoor fan control table 400 shown in fig. 6 (a). Fig. 10 is a subroutine of the processing performed by the control means during the indoor heat exchange heating operation, and shows the flow of the processing relating to the temperature maintaining outdoor fan control performed when the indoor heat exchange temperature Tc is maintained within the range of 55 to 57 ℃ by using the outdoor fan control table 500 shown in fig. 6 (B).
In each of the flowcharts of fig. 7 to 10, ST represents a step of processing, and the following numerals represent step numbers. In addition, with respect to Tc1 to Tc4 (hereinafter, referred to as first indoor heat exchange temperature Tc1 to fourth indoor heat exchange temperature Tc4) shown in fig. 7 and 9, the second indoor heat exchange temperature Tc2 to fourth indoor heat exchange temperature Tc4 correspond to the indoor heat exchange temperature Tc shown in the indoor fan control table 400, the second indoor heat exchange temperature Tc2 is 53 ℃, the third indoor heat exchange temperature Tc3 is 55 ℃, and the fourth indoor heat exchange temperature Tc4 is 57 ℃. The first indoor heat exchange temperature Tc1 is a temperature at which a temperature maintaining operation described later is started, and is a temperature lower than the second indoor heat exchange temperature Tc2 by a predetermined temperature, for example, 50 ℃. Further, the third indoor heat exchange temperature Tc3 is the first temperature of the present invention, the fourth indoor heat exchange temperature Tc4 is the second temperature of the present invention, and the first indoor heat exchange temperature Tc1 is the third temperature of the present invention.
< main program: control of indoor Heat exchange heating operation >
First, the process related to the indoor heat exchange heating operation control will be described with reference to fig. 7. If an instruction to perform the indoor heat exchange heating operation is received from the user or the air conditioner 1 ends the cooling operation, the control unit first performs the pre-heating operation control as a subroutine of the indoor heat exchange heating operation control (ST 41). The operation control before heating will be described later.
Next, the control unit drives the compressor 21 at a predetermined minimum rotation speed (hereinafter referred to as a compressor minimum rotation speed Rcm) (ST 42). Specifically, the CPU210 of the outdoor unit control unit 200 reads the compressor minimum rotation speed Rcm stored in the storage unit 220 in advance, and drives the compressor 21 at the read compressor minimum rotation speed Rcm. Here, it is known that the compressor minimum rotation speed Rcm is obtained in advance by performing an experiment or the like, and is a rotation speed at which the discharge pressure of the compressor 21 does not exceed the upper limit value of the usage range even in a situation where the indoor heat exchange temperature Tc is set higher than that in the normal heating operation in the indoor heat exchange heating operation. The minimum rotational speed Rcm of the compressor is, for example, 30 rps.
Next, the control means sets the expansion valve 24 to a predetermined opening degree (hereinafter referred to as a predetermined expansion valve opening degree Dp) (ST 43). Specifically, the CPU210 of the outdoor unit control unit 200 reads a predetermined expansion valve opening Dp stored in the storage unit 220 in advance, and adds a drive pulse corresponding to the predetermined expansion valve opening Dp to the step motor, not shown, of the expansion valve 24 so that the expansion valve opening D becomes the read predetermined expansion valve opening Dp. Here, the predetermined expansion valve opening Dp is an opening through which the refrigerant of an amount necessary to control the indoor heat exchange temperature Tc to a temperature in a range of 55 ℃ or more and less than 57 ℃ only by the control of the indoor fan 32 flows through the indoor heat exchanger 31 when the indoor heat exchange heating operation of the present invention is performed by the air conditioner 1, which is determined in advance through experiments or the like. The predetermined expansion valve opening Dp is, for example, 200 pulses when represented by the number of driving pulses applied to the expansion valve 24.
Next, the control means sets the outdoor fan rotation speed Rfo to a rotation speed corresponding to the compressor rotation speed Rc (ST 44). Specifically, the CPU210 drives the outdoor fan 27 at an outdoor fan rotation speed Rfo corresponding to the compressor rotation speed Rc. At the time of the process of ST43, since the outdoor fan 27 is already driven by the pre-heating operation control described later, the outdoor fan rotation speed Rfo is changed to a rotation speed corresponding to the compressor rotation speed Rc in ST43, and the outdoor fan rotation speed Rfo at this time is, for example, 500 rpm.
Next, the control unit sets the indoor fan 32 to a predetermined rotation speed (hereinafter referred to as an indoor fan initial rotation speed Rfip) (ST 45). Specifically, the CPU310 of the indoor unit control unit 300 reads the indoor fan initial rotation speed Rfip stored in the storage unit 320 in advance as the indoor fan initial rotation speed Rfip from which the indoor fan rotation speed Rfi is read, and drives the indoor fan 32. Here, the indoor fan initial rotation speed Rfip is a rotation speed at which the indoor heat exchange temperature Tc is quickly increased while preventing the indoor heat exchange temperature Tc from being stopped in protection by the protection control during the indoor heat exchange heating operation described later, because the amount of indoor air supplied to the indoor heat exchanger 31 by the rotation of the indoor fan 32 is small, and the indoor heat exchange temperature Tc is prevented from rapidly increasing, which is obtained in advance by performing a test or the like. The initial indoor fan rotation speed Rfip is, for example, 600 rpm. At the time of the process of ST44, since the indoor fan 32 is already driven by the pre-heating operation control described later, the indoor fan rotation speed Rfi is changed to the indoor fan initial rotation speed Rfip in ST 44.
Next, the control unit sets the up-down wind direction plate 35 to the horizontal position (ST 46). Specifically, the CPU310 rotates the up-down wind direction plate 35 to the horizontal position. If the up-down wind direction plate 35 is in the horizontal position, a part of the air heated in the indoor heat exchanger 31 and blown out from the blow-out port 30g can be sucked into the suction port 30 f. Therefore, the indoor heat exchange temperature Tc rises more rapidly than in the case where the up-down wind direction plate 35 is in a position other than the horizontal position.
Next, the control unit starts measurement of the timer 1(ST 47). Specifically, CPU310 has a timer measurement function, and CPU310 starts measurement by timer 1. The timer measurement function may be provided in the CPU210, or may be provided outside the CPU210 and the CPU 310. Next, the control unit takes in the indoor heat exchange temperature Tc (ST 48). Specifically, the CPU310 periodically (for example, every 30 seconds) takes in the indoor heat exchange temperature Tc detected by the indoor heat exchange temperature sensor 74 via the sensor input unit 340.
Next, the control unit determines whether the indoor heat exchange temperature Tc taken in ST48 is lower than the first indoor heat exchange temperature Tc1(ST 49). Specifically, the CPU310 reads the first indoor heat exchange temperature Tc1 from the storage unit 320 and compares the read indoor heat exchange temperature Tc with the taken-in indoor heat exchange temperature Tc.
If the acquired indoor heat exchange temperature Tc is lower than the first indoor heat exchange temperature Tc1(ST 49-Yes), the control unit determines whether a prescribed time (hereinafter referred to as a first prescribed time tp1) has elapsed after the start of the measurement of the timer 1 in ST47 (ST 58). Specifically, the CPU310 determines whether or not the first prescribed time tp1 has elapsed after the start of measurement of the timer 1 at ST 47. Here, the first predetermined time tp1 is predetermined and stored in the storage unit 320, for example, 10 minutes.
If the first predetermined time tp1 has elapsed (ST 58-Yes), the control unit resets the timer 1(ST61) and ends the indoor unit heat-exchange heating operation control. Specifically, the CPU310 resets the timer 1, stops the indoor fan 32, and transmits a signal including a message to end the indoor unit heat exchange heating operation control to the outdoor unit 2 via the communication unit 330. The CPU210 receiving this signal via the communication unit 230 stops the compressor 21 and the outdoor fan 27.
If the first prescribed time tp1 has not elapsed (ST 58-No), the control unit judges whether or not the current indoor fan rotational speed Rfi is a prescribed minimum rotational speed (hereinafter referred to as the indoor fan minimum rotational speed Rfim) (ST 59). Specifically, the CPU310 reads out the minimum indoor fan rotation speed Rfim stored in the storage unit 320 in advance, and compares the minimum indoor fan rotation speed Rfim with the current indoor fan rotation speed Rfi. Here, the minimum indoor fan rotation speed Rfim is the lower limit rotation speed of the usage range of the indoor fan 32, and is, for example, 300 rpm.
If the current indoor fan rotational speed Rfi is the indoor fan minimum rotational speed Rfim (ST 59-Yes), the control unit maintains the indoor fan minimum rotational speed Rfim (ST60), i.e., continues to drive the indoor fan 32 at the indoor fan minimum rotational speed Rfim, returning the process to ST 48. Specifically, the CPU310 continues to drive the indoor fan 32 at the indoor fan minimum rotation speed Rfim.
On the other hand, if the current indoor fan rotational speed Rfi is not the indoor fan minimum rotational speed Rfim (ST 59-No), the control unit decreases the indoor fan rotational speed Rfi by a predetermined indoor fan release rotational speed (hereinafter referred to as the indoor fan release rotational speed Rfir) for a predetermined indoor fan release interval time (hereinafter referred to as the indoor fan release interval time tfi) (ST62), and returns the process to ST 48. Specifically, the CPU310 decreases the indoor fan release rotational speed Rfir every indoor fan release interval time tfi by the indoor fan rotational speed rfii. The indoor fan emission interval time tfi and the indoor fan emission rotation speed Rfir are determined in advance by performing an experiment or the like, and it is confirmed that the indoor heat exchange temperature Tc is increased while suppressing a rapid increase in the indoor heat exchange temperature Tc and stopping the protection by the protection control during the indoor heat exchange heating operation described later. The indoor fan release interval time tfi is, for example, 60 seconds, and the indoor fan release rotational speed Rfir is, for example, 50 rpm.
The processes of ST47 to ST49 and ST58 to ST62 described above are processes related to an operation for raising the indoor heat exchange temperature Tc to the first indoor heat exchange temperature Tc1 (hereinafter referred to as a temperature raising operation) in the indoor unit heat exchange heating operation. By performing the temperature raising operation, the indoor heat exchange temperature Tc can be raised to the first indoor temperature Tc1 (50 ℃ in the present embodiment) as quickly as possible while preventing the protection stop due to the protection control during the indoor heat exchange heating operation, which will be described later.
In the process of ST58, when the indoor heat exchange temperature Tc has not reached the first indoor heat exchange temperature Tc1 or more even after the first predetermined time tp1 has elapsed, the indoor heat exchange heating operation is ended. This is to avoid the following: when the indoor heat exchange temperature Tc does not reach the first indoor heat exchange temperature Tc1 or more even if the temperature raising operation is performed for the first predetermined time tp1, the indoor heat exchange temperature Tc is in a state in which it is difficult to raise the temperature due to some reason, and the indoor heat exchange heating operation is continued in this state, which results in wasteful operation.
In ST49, if the taken-in indoor heat exchange temperature Tc is not lower than the first indoor heat exchange temperature Tc1(ST 49-No), the control unit starts measurement by the timer 2(ST 50). Specifically, the CPU310 starts measurement of the timer 2.
Next, the control unit executes the temperature maintaining indoor fan control as a subroutine of the indoor heat exchange heating operation control (ST51), and at the same time, executes the temperature maintaining outdoor fan control as a subroutine of the indoor heat exchange heating operation control (ST 52). The temperature maintenance indoor fan control and the temperature maintenance outdoor fan control will be described later.
Next, the control unit determines whether the flag is 1(ST 53). This flag is, for example, a flag of the CPU310, and changes from 0 to 1 when the indoor heat exchange temperature Tc rises and first reaches the third indoor heat exchange temperature Tc3 (55 ℃ in the present embodiment) or higher during the indoor heat exchange heating operation. The flag is set to 0 by default (factory shipment).
If the flag is 1(ST 53-Yes), that is, if the indoor heat exchange temperature Tc has reached the third indoor heat exchange temperature Tc3, the control unit resets the timer 1(ST 63) and advances the process to ST 56. Specifically, if the CPU310 acknowledges the flag as 1, timer 1 is reset.
If the flag is not 1(ST 53-No), that is, if the indoor heat exchange temperature Tc has not reached the third indoor heat exchange temperature Tc3, the control unit judges whether or not the indoor heat exchange temperature Tc taken in ST48 is above the third indoor heat exchange temperature Tc3(ST 54). Specifically, the CPU310 reads the third indoor heat exchange temperature Tc3 from the storage unit 320 and compares the read indoor heat exchange temperature Tc with the acquired indoor heat exchange temperature Tc.
If the taken indoor heat exchange temperature Tc becomes equal to or higher than the third indoor heat exchange temperature Tc3(ST 54-Yes), the control unit resets the timer 1 while setting the flag to 1(ST 55), and advances the process to ST 56. Specifically, the CPU310 sets the flag to 1 and simultaneously resets the timer 1.
If the taken-in indoor heat exchange temperature Tc does not reach the third indoor heat exchange temperature Tc3 or more (ST 54-No), the control unit judges whether or not the first prescribed time tp1 has elapsed after the start of the measurement by the timer 1 in ST47 (ST 64). The process of ST63 is performed by the CPU310 in the same manner as the process of ST 58.
If the first predetermined time tp1 has elapsed (ST 64-Yes), the control unit resets the timer 1(ST65) and ends the indoor unit heat-exchange heating operation control. The process of ST65 is performed by the CPU310 in the same manner as the process of ST 61. If the first prescribed time tp1 has not elapsed (ST 64-No), the control unit returns the process to ST 53.
In the process of ST64, when the indoor heat exchange temperature Tc is not equal to or higher than the third indoor heat exchange temperature Tc3 even after the first predetermined time tp1 elapses, the indoor heat exchange heating operation is ended. This is to avoid the following: even if the above-described temperature raising operation and the temperature maintaining operation described later are performed for the first predetermined time tp1, if the indoor heat exchange temperature Tc does not reach the third indoor heat exchange temperature Tc3 or more, the indoor heat exchange temperature Tc becomes a state in which it is difficult to increase due to some reason, and as a result, the indoor heat exchange heating operation is continued in this state, which results in wasteful operation.
The control unit that has finished the process of ST55 determines whether or not a predetermined time (hereinafter referred to as a second predetermined time tp2) has elapsed after the start of the measurement of the timer 2 in ST50 (ST 56). Specifically, the CPU310 determines whether or not the second prescribed time tp2 has elapsed after the start of the measurement of the timer 2 in ST 50. Here, the second predetermined time tp2 is a time for maintaining the indoor heat exchange temperature Tc at 55 ℃ or higher, for example, 10 minutes, in order to greatly reduce the number of mold and bacteria existing in the indoor heat exchanger 31, and is stored in the storage unit 320.
If the second prescribed time tp2 has not elapsed (ST 56-No), the control unit returns the process to ST 51. If the second predetermined time tp2 has elapsed (ST 56-Yes), the control unit resets the timer 2 and also resets the flag (ST57), and ends the indoor unit heat-exchange heating operation control. Specifically, CPU310 resets timer 2, while resetting the flag. Further, the CPU310 stops the indoor fan 32 and transmits a signal including a message to end the indoor unit heat exchange heating operation control to the outdoor unit 2 via the communication unit 330. The CPU210 receiving this signal via the communication unit 230 stops the compressor 21 and the outdoor fan 27.
The processing of ST50 to ST56 and ST63 to ST65 described above is processing relating to an operation (hereinafter referred to as a temperature maintaining operation) in which the indoor heat exchange temperature Tc is maintained at or above the third indoor heat exchange temperature Tc3 (55 ℃ in the present embodiment) for the second predetermined time tp 2. By continuing the temperature maintaining operation for the second predetermined time tp2, the number of mold and bacteria present in the indoor heat exchanger 31 can be significantly reduced as compared with the case where the conventional drying operation is performed at an indoor heat exchange temperature Tc of about 40 ℃.
< subroutine: control of operation before heating >
Next, the operation control before heating, which is a subroutine of the indoor heat exchange heating operation control, will be described with reference to fig. 8. In the pre-heating operation control, the compressor 21 is stopped, and the refrigerant is not circulated through the refrigerant circuit 10.
First, the control unit determines whether or not the cooling operation is performed before the indoor heat exchange heating operation (ST 71). If the cooling operation is not performed (ST 71-No), the control unit ends the pre-heating operation control. If the cooling operation is performed (ST 71-Yes), the control unit starts the measurement of the timer 3(ST 72). Specifically, CPU310 starts measurement by timer 3.
Next, the control unit drives the indoor fan 32 with the indoor fan rotation speed Rfi set to a predetermined rotation speed (hereinafter referred to as the heating front indoor fan rotation speed Rfia) (ST 73). Specifically, CPU310 sets indoor fan rotation speed Rfi to heating front indoor fan rotation speed Rfia, and drives indoor fan 32. Here, the heating front indoor fan rotation speed Rfia is obtained in advance by an experiment or the like, and is a rotation speed at which dew condensation water is prevented from being generated due to a temperature difference between the temperature of the indoor unit 3 and the indoor heat exchange temperature Tc during the temperature increase operation by allowing indoor air to pass through the inside of the indoor unit 3 to heat the indoor unit 3 cooled in the cooling operation during a third predetermined time tp3 described later. The heating front chamber fan speed Rfia is, for example, 900 rpm.
Next, the control unit sets the outdoor fan rotation speed Rfo to a predetermined rotation speed (hereinafter referred to as the heating front outdoor fan rotation speed Rfoa) and drives the outdoor fan 27(ST 74). Specifically, CPU210 sets outdoor fan rotation speed Rfo to heating front outdoor fan rotation speed Rfoa and drives outdoor fan 27. Here, the heating front outdoor fan rotation speed Rfoa is obtained by performing a test or the like in advance, and is a rotation speed at which an excessive increase in temperature of the outdoor unit control unit 200 during the indoor heat exchange heating operation is suppressed by cooling the outdoor unit control unit 200 (particularly, an inverter (not shown) that drives the compressor 21) that generates heat during the cooling operation during a third predetermined time tp3 described later. The heating front outdoor fan speed Rfoa is, for example, 650 rpm.
Next, the control unit determines whether or not a predetermined time (hereinafter referred to as a third predetermined time tp3) has elapsed after the start of measurement of the timer 3 in ST72 (ST 75). Specifically, CPU310 determines whether or not the third prescribed time tp3 has elapsed after the start of measurement of timer 3 at ST 75. Here, the third predetermined time tp3 is predetermined and stored in the storage unit 320, and is a time period as follows: if the indoor fan rotation speed Rfi is set to the heating front indoor fan rotation speed Rfia and the outdoor fan rotation speed Rfo is set to the heating front outdoor fan rotation speed Rfoa and the respective motors are driven for the third predetermined time tp3, the indoor unit 3 cooled in the cooling operation can be heated to such a degree that dew condensation water does not occur in the heating operation, and the outdoor unit control unit 200 that generates heat in the cooling operation can be cooled. The third predetermined time tp3 is, for example, 15 minutes.
If the third prescribed time tp3 has not elapsed (ST 75-No), the control unit returns the process to ST 75. If the third predetermined time tp3 has elapsed (ST 75-Yes), the control unit resets the timer 3(ST76), and ends the pre-heating operation control and returns to the main routine.
As described above, when the cooling operation is performed before the indoor heat exchange heating operation, the pre-heating operation is controlled before the temperature increasing operation, whereby the casing 30 of the indoor unit 3 cooled during the cooling operation can be heated. This can suppress the occurrence of dew condensation water in the casing 30 due to the temperature difference between the temperature of the indoor unit 3 and the indoor heat exchange temperature Tc during the temperature raising operation, and therefore dew condensation water can be prevented from scattering into the room from the air outlet 30g of the indoor unit 3 during the indoor heat exchange heating operation. Further, by driving the outdoor fan 27 by the pre-heating operation control, the outdoor unit control unit 200 that reaches a high temperature during the cooling operation in which the outside air temperature is high can be cooled.
< subroutine: control of indoor Fan during temperature maintenance >
Next, the temperature maintaining indoor fan control which is a subroutine of the indoor heat exchange heating operation control will be described with reference to fig. 9. Since the drive control of the indoor fan 32 is performed only by the indoor unit control unit 300, the CPU310 whose control body is the indoor unit control unit 300 will be described below.
First, the CPU310 takes in the indoor heat exchange temperature Tc (ST 80). The acquisition of the indoor heat exchange temperature Tc is performed by the same method as ST11 in the protection control during heating operation described with reference to fig. 4, and therefore, the description thereof is omitted. Next, the CPU310 calculates a temperature difference (hereinafter referred to as an indoor heat exchange temperature difference Δ Tc) obtained by subtracting the indoor heat exchange temperature Tc acquired immediately before (for example, 30 seconds before) from the indoor heat exchange temperature Tc acquired most recently by using the two indoor heat exchange temperatures Tc acquired at intervals (ST 81).
Next, the CPU310 determines whether or not the indoor heat exchange temperature difference Δ Tc calculated in ST81 exceeds 0, that is, whether or not the indoor heat exchange temperature Tc rises (ST 82). If the indoor heat exchange temperature difference Δ Tc exceeds 0(ST 82-Yes), the CPU310 refers to "Tc-up time" of the indoor fan control table 400 of fig. 6 stored in the storage unit 320, and performs the following processes ST83 to ST 85.
First, the CPU310 determines whether the current indoor heat exchange temperature Tc is lower than the third indoor heat exchange temperature Tc3(ST 83). If the current indoor heat exchange temperature Tc is lower than the third indoor heat exchange temperature Tc3(ST 83-Yes), the CPU310 sets the indoor fan rotation speed Rfi to a rotation speed obtained by subtracting 10rpm from the current indoor fan rotation speed Rfi (ST86), ends the temperature maintaining indoor fan control, and returns to the main routine.
If the current indoor heat exchange temperature Tc is not lower than the third indoor heat exchange temperature Tc3(ST 83-No), the CPU310 determines whether the current indoor heat exchange temperature Tc is above the third indoor heat exchange temperature Tc3 and lower than the fourth indoor heat exchange temperature Tc4(ST 84). If the current indoor heat exchange temperature Tc is above the third indoor heat exchange temperature Tc3 and below the fourth indoor heat exchange temperature Tc4(ST 84-Yes), the CPU310 does not change the indoor fan rotation speed Rfi (ST87), ends the temperature maintaining indoor fan control, and returns to the main routine.
If the current indoor heat exchange temperature Tc is not equal to or higher than the third indoor heat exchange temperature Tc3 but lower than the fourth indoor heat exchange temperature Tc4(ST 84-No), that is, if the current indoor heat exchange temperature Tc is equal to or higher than the fourth indoor heat exchange temperature Tc4, the CPU310 sets the indoor fan rotation speed Rfi to a rotation speed obtained by adding 70rpm to the current indoor fan rotation speed Rfi (ST85), ends the temperature-maintaining indoor fan control, and returns to the main routine.
In ST82, if the indoor heat exchange temperature difference Δ Tc does not exceed 0(ST 82-No), the CPU310 determines whether the indoor heat exchange temperature difference Δ Tc calculated in ST81 is 0, that is, whether the indoor heat exchange temperature Tc has not changed (ST 88). If the indoor heat exchange temperature difference Δ Tc is 0(ST 88-Yes), the CPU310 refers to "Tc maintenance time" of the indoor fan control table 400 of fig. 6 stored in the storage unit 320, and performs the following processes ST89 to ST 95.
First, the CPU310 determines whether the current indoor heat exchange temperature Tc is lower than the second indoor heat exchange temperature Tc2(ST 89). If the current indoor heat exchange temperature Tc is lower than the second indoor heat exchange temperature Tc2(ST 89-Yes), the CPU310 sets the indoor fan rotation speed Rfi to a rotation speed obtained by subtracting 40rpm from the current indoor fan rotation speed Rfi (ST93), ends the temperature maintenance-time indoor fan control, and returns to the main routine.
If the current indoor heat exchange temperature Tc is not lower than the second indoor heat exchange temperature Tc2(ST 89-No), the CPU310 determines whether the current indoor heat exchange temperature Tc is above the second indoor heat exchange temperature Tc2 and below the third indoor heat exchange temperature Tc3(ST 90). If the current indoor heat exchange temperature Tc is equal to or higher than the second indoor heat exchange temperature Tc2 and lower than the third indoor heat exchange temperature Tc3(ST 90-Yes), the CPU310 sets the indoor fan rotation speed Rfi to a rotation speed obtained by subtracting 30rpm from the current indoor fan rotation speed Rfi (ST94), ends the temperature maintaining indoor fan control, and returns to the main routine.
If the current indoor heat exchange temperature Tc is not more than the second indoor heat exchange temperature Tc2 and is lower than the third indoor heat exchange temperature Tc3(ST 90-No), the CPU310 determines whether the current indoor heat exchange temperature Tc is more than the third indoor heat exchange temperature Tc3 and is lower than the fourth indoor heat exchange temperature Tc4(ST 91). If the current indoor heat exchange temperature Tc is equal to or higher than the third indoor heat exchange temperature Tc3 and lower than the fourth indoor heat exchange temperature Tc4(ST 91-Yes), the CPU310 ends the temperature maintaining indoor fan control without changing the indoor fan rotation speed Rfi (ST95), and returns to the main routine.
If the current indoor heat exchange temperature Tc is not equal to or higher than the third indoor heat exchange temperature Tc3 but lower than the fourth indoor heat exchange temperature Tc4(ST 93-No), that is, if the current indoor heat exchange temperature Tc is equal to or higher than the fourth indoor heat exchange temperature Tc4, the CPU310 sets the indoor fan rotation speed Rfi to a rotation speed obtained by adding 50rpm to the current indoor fan rotation speed Rfi (ST92), ends the temperature-maintaining indoor fan control, and returns to the main routine.
In ST88, if the indoor heat exchange temperature difference Δ Tc is not 0(ST 88-No), that is, if the indoor heat exchange temperature Tc decreases, the CPU310 refers to "Tc-decrease time" of the indoor fan control table 400 of fig. 6 stored in the storage unit 320, and performs the following processing of ST96 to ST 98.
First, the CPU310 determines whether the current indoor heat exchange temperature Tc is lower than the third indoor heat exchange temperature Tc3(ST 96). If the current indoor heat exchange temperature Tc is lower than the third indoor heat exchange temperature Tc3(ST 96-Yes), the CPU310 sets the indoor fan rotation speed Rfi to a rotation speed obtained by subtracting 40rpm from the current indoor fan rotation speed Rfi (ST98), ends the temperature maintaining indoor fan control, and returns to the main routine.
If the current indoor heat exchange temperature Tc is not lower than the third indoor heat exchange temperature Tc3(ST 96-No), that is, the current indoor heat exchange temperature Tc is higher than the third indoor heat exchange temperature Tc3, the CPU310 does not change the indoor fan rotation speed Rfi (ST97), ends the temperature maintenance indoor fan rotation speed control, and returns to the main routine.
Further, as described above, when the temperature maintenance indoor fan control is performed using the indoor fan control table 400, the indoor fan rotation speed Rfi is set between the upper limit rotation speed and the lower limit rotation speed (900rpm and 300rpm) of the indoor fan rotation speed Rfi. If the indoor fan rotation speed Rfi is increased every time the rotation speed determined in the indoor fan control table 400 reaches 900rpm, the indoor fan rotation speed Rfi is maintained at 900rpm even in the case where the indoor fan rotation speed Rfi is increased later. In addition, if the indoor fan rotation speed Rfi is lowered every time the rotation speed determined in the indoor fan control table 400 reaches 300rpm, the indoor fan rotation speed Rfi is maintained at 300rpm even in the case where the indoor fan rotation speed Rfi is lowered thereafter.
As described above, in the temperature maintaining operation performed during the indoor heat exchange heating operation, the indoor fan control during temperature maintaining is performed using the indoor fan control table 400, whereby the indoor heat exchange temperature Tc can be maintained between the third indoor heat exchange temperature Tc3(═ 55 ℃) and the fourth indoor heat exchange temperature Tc4(═ 57 ℃) for 10 minutes.
< subroutine: control of outdoor Fan during temperature maintenance >
Next, the temperature maintenance outdoor fan control, which is a subroutine of the indoor heat exchange heating operation control, will be described. Since the drive control of the outdoor fan 27 is performed only by the outdoor unit control unit 200, the CPU210 whose control body is the outdoor unit control unit 200 will be described below.
First, the CPU210 takes in the indoor temperature Ti from the indoor unit 3 via the communication unit 230 and takes in the outside air temperature To detected by the outside air temperature sensor 73 via the sensor input unit 240 (ST 111). Further, the CPU210 periodically (for example, every 30 seconds) takes in the indoor temperature Ti and the outside air temperature To.
Next, the CPU210 determines whether the outside air temperature To taken in at ST111 is lower than a predetermined first outside air temperature (hereinafter referred To as a first threshold outside air temperature Top1) (ST 112). For example, the first threshold outside air temperature Top1 is the outside air temperature determined in the outdoor fan control table 500 of fig. 6 (B): 16 ℃ is adopted.
If the taken-in outside air temperature To is lower than the first threshold outside air temperature Top1(ST 112-Yes), the CPU210 refers To the outdoor fan control table 500 stored in the storage unit 220, drives the outdoor fan 27 at the outdoor fan rotation speed Rfo corresponding To the compressor rotation speed Rc (ST117), ends the temperature-maintaining outdoor fan control, and returns To the main routine.
If the taken-in outside air temperature To is not lower than the first threshold outside air temperature Top1(ST 112-No), the CPU210 determines whether the taken-in outside air temperature To is equal To or higher than the first threshold outside air temperature Top1 and lower than a prescribed second outside air temperature (hereinafter referred To as a second threshold outside air temperature Top2) (ST 113). The second threshold outside air temperature Top2 is a temperature higher than the first threshold outside air temperature Top1, and is, for example, the outside air temperature determined in the outdoor fan control table 500 of fig. 6 (B): 24 ℃.
If the taken outside air temperature To is not equal To or higher than the first threshold outside air temperature Top1 but lower than the second threshold outside air temperature Top2(ST 113-No), that is, if the taken outside air temperature To is equal To or higher than the second threshold outside air temperature Top2, the CPU210 refers To the outdoor fan control table 500 stored in the storage unit 220, sets the outdoor fan rotation speed Rfo To 0rpm (ST118), that is, stops the outdoor fan 27, ends the temperature-maintaining outdoor fan control, and returns the main routine To the first embodiment.
If the taken-in outside air temperature To is equal To or higher than the first threshold outside air temperature Top1 and lower than the second threshold outside air temperature Top2(ST 113-Yes), the CPU210 determines whether the indoor temperature Ti taken in ST111 is lower than a predetermined indoor temperature (hereinafter referred To as threshold indoor temperature Tip) (ST 114). For example, the threshold indoor temperature Tip is the indoor temperature determined in the outdoor fan control table 500 of fig. 6 (B): at a temperature of 27 ℃.
If the taken indoor temperature Ti is not lower than the threshold indoor temperature Tip (ST 114-No), that is, if the taken indoor temperature Ti is not lower than the threshold indoor temperature Tip, the CPU210 advances the process to ST 118. If the taken indoor temperature Ti is lower than the threshold indoor temperature Tip (ST 114-Yes), the CPU210 judges whether the current outdoor fan rotation speed Rfo is 0rpm (ST 115).
If the current outdoor fan rotational speed Rfo is 0rpm (ST 115-Yes), the CPU210 advances the process to ST118, i.e., maintains the state where the outdoor fan 27 is stopped. If the current outdoor fan rotation speed Rfo does not reach 0rpm (ST 115-No), the CPU210 sets the outdoor fan rotation speed Rfo to a predetermined rotation speed (hereinafter referred to as the maintenance-time outdoor fan rotation speed Rfob) (ST116), ends the temperature maintenance-time outdoor fan control, and returns to the main routine. For example, the maintained outdoor fan rotation speed Rfob is the outdoor fan rotation speed Rfo determined in the outdoor fan control table 500 of fig. 6 (B): 190 rpm.
As described above, in the temperature maintaining operation performed during the indoor heat exchange heating operation, the outdoor fan control table 500 is used to perform the temperature maintaining outdoor fan control. Thus, by controlling the outdoor fan 27 based on the outdoor fan control table 500, the discharge pressure of the compressor 21 can be made not to exceed the upper limit of the use range while maintaining the indoor heat exchange temperature Tc in the range of 55 to 57 ℃.
As described in the above-described processing of ST115, in the temperature-maintaining outdoor fan control, when the outdoor fan 27 is stopped, the outdoor fan 27 is not driven until the indoor heat-exchange heating operation is completed thereafter. This is to prevent the discharge pressure of the compressor 21 from rising and exceeding the upper limit of the usage range, while the evaporation capacity of the outdoor heat exchanger 23 is rising and the evaporation pressure is rising, by restarting the outdoor fan 27 when the indoor heat exchange temperature Tc is maintained at 55 ℃.
< control of protection during indoor Heat exchange heating operation >
Next, the protection control during the indoor heat exchange heating operation in which the discharge pressure of the compressor 21 does not exceed the upper limit value of the usage range during the indoor heat exchange heating operation will be described with reference to fig. 11. In fig. 11, ST denotes a step of processing, and the following numerals denote step numbers. The indoor heat exchange heating time protection control is executed when the indoor heat exchange heating is performed, and is different from the heating operation time protection control executed when the heating operation is performed.
First, the control unit takes in the indoor heat exchange temperature Tc, the discharge temperature Td, the temperature of the outdoor heat exchanger 23 (hereinafter referred To as outdoor heat exchange temperature Te), and the outside air temperature To (ST 131). The indoor heat exchange temperature Tc and the discharge temperature Td are obtained by the same method as ST11 in the heating operation protection control described with reference to fig. 4, and therefore, the description thereof is omitted. The outside air temperature To is taken in by the same method as ST111 in the temperature maintaining outdoor fan control described with reference To fig. 10, and therefore, the description thereof is omitted. The outdoor heat-exchange temperature Te is the outdoor heat-exchange temperature Te detected by the outdoor heat-exchange sensor 72 that the CPU210 periodically (for example, every 30 seconds) takes in via the sensor input section 240.
Next, the control unit determines whether or not the indoor heat exchange temperature Tc acquired in ST131 is higher than the first threshold indoor heat exchange temperature Tch1, i.e., a predetermined temperature (hereinafter referred to as a second threshold indoor heat exchange temperature Tch2) or higher (ST 132). Specifically, the CPU310 reads the second threshold indoor heat exchange temperature Tch2 stored in the storage unit 320 in advance, and compares the indoor heat exchange temperature Tch with the indoor heat exchange temperature Tc. The second threshold indoor heat exchange temperature Tch2 is obtained in advance through a test or the like, and is a temperature higher than the first threshold indoor heat exchange temperature Tch1 and lower than the indoor heat exchange temperature Tc corresponding to the upper limit value of the use range of the discharge pressure of the compressor 21 by a predetermined temperature. The second threshold indoor heat exchange temperature Tch2 is, for example, 59 ℃.
If the indoor heat exchange temperature Tc is equal to or higher than the second threshold indoor heat exchange temperature Tch 2(ST 132-Yes), the control unit stops the indoor heat exchange heating operation (ST136) and ends the processing relating to the protection control during the indoor heat exchange heating operation. After the process of ST136 is performed, the operation of the air conditioner 1 may be stopped. Further, the compressor 21 may be stopped, and only the blowing operation of driving the indoor fan 32 may be continued. Alternatively, the drying operation of the indoor heat exchanger 31 may be continued for a certain period of time by driving the compressor 21 at a predetermined rotational speed, opening the opening degree D of the expansion valve 24 at an opening degree larger than the predetermined expansion valve opening degree Dp in the indoor heat exchange heating operation, driving the indoor fan 32 at an indoor fan rotational speed Rfi higher than that in the indoor heat exchange heating operation. In this drying operation, the opening degree D of the expansion valve 24 is increased and the indoor fan rotation speed Rfi is also increased as compared with the indoor heat exchange heating operation, so the discharge pressure of the compressor 21 is lower than that in the indoor heat exchange heating operation.
If the indoor heat exchange temperature Tc is not greater than the second threshold indoor heat exchange temperature Tch 2(ST 132-No), the control unit determines whether the discharge temperature Td taken in ST131 is greater than or equal to the first threshold discharge temperature Tdh 1(ST 133). Specifically, the CPU210 determines whether or not the discharge temperature Td is equal to or higher than a first threshold discharge temperature Tdh 1.
If the fetched discharge temperature Td is above the first threshold discharge temperature Tdh 1(ST 133-Yes), the control unit advances the process to ST 136.
If the taken discharge temperature Td is not equal to or higher than the first threshold discharge temperature Tdh 1(ST 133-No), the control unit determines whether or not the outdoor heat-exchange temperature Te taken in ST131 is equal to or higher than a predetermined outdoor heat-exchange temperature (hereinafter referred to as a threshold outdoor heat-exchange temperature Teh) (ST 134). Specifically, the CPU210 determines whether or not the taken-in outdoor heat-exchange temperature Te is equal to or higher than a threshold outdoor heat-exchange temperature Teh. Here, the threshold outdoor heat exchange temperature Teh is obtained in advance by an experiment or the like and stored in the storage unit 220, and if the outdoor heat exchange temperature Te is equal to or higher than the threshold outdoor heat exchange temperature Teh, the suction pressure of the compressor 21 increases, and the compression ratio (ratio of the discharge pressure to the suction pressure) of the compressor 21 may become lower than the lower limit value of the usage range.
If the taken outdoor heat-exchange temperature Te is the threshold outdoor heat-exchange temperature Teh or more (ST 134-Yes), the control unit advances the process to ST 136.
If the taken outdoor heat exchange temperature Te is not equal To or higher than the threshold outdoor heat exchange temperature Teh (ST 134-No), the control unit determines whether or not the outdoor air temperature To taken in ST131 is equal To or higher than a predetermined outdoor air temperature (hereinafter referred To as a third threshold outdoor air temperature Top3) (ST 135). Specifically, the CPU310 determines whether the taken-in outside air temperature To is equal To or higher than the third threshold outside air temperature Top 3. Here, the third threshold outdoor air temperature Top3 is determined in advance by an experiment or the like and stored in the storage unit 220, and is a temperature at which the discharge pressure of the compressor 21 may excessively increase and the discharge pressure of the compressor 21 may exceed the lower limit value of the usage range if the indoor heat exchange heating operation is performed when the outdoor air temperature To is equal To or higher than the third threshold outdoor air temperature Top 3. The third threshold outside air temperature Top3 is a temperature higher than the above-described first threshold outside air temperature Top1 or second threshold outside air temperature Top2, and is, for example, 43 ℃.
If the taken outside air temperature To is not equal To or higher than the third threshold outside air temperature Top 3(ST 134-No), the control unit returns the process To ST 131. If the taken outside air temperature To is equal To or higher than the third threshold outside air temperature Top 3(ST 134-Yes), the control unit returns the process To ST 136.
As described above, in the protection control during the indoor heat exchange heating operation, the compressor 21 is not stopped until the indoor heat exchange temperature Tc becomes equal to or higher than the second threshold indoor heat exchange temperature Tch2(═ 59 ℃) which is higher than the first threshold indoor heat exchange temperature Tch1(═ 55 ℃) in the protection control during the heating operation. Thus, during the outdoor heat exchange heating operation, the indoor heat exchange temperature Tc can be maintained at 55 to 57 ℃, and if the indoor heat exchange temperature Tc is equal to or higher than the second threshold indoor heat exchange temperature Tch2, the compressor 21 is stopped, so that the discharge pressure of the compressor 21 can be suppressed from exceeding the upper limit of the usage range.
In the protection control during the indoor heat exchange heating operation, if the discharge temperature Td of the compressor 21 is lower than the second threshold discharge temperature Tdh2(═ 115 ℃) which is the threshold temperature at which the compressor 21 is stopped under the protection control during the heating operation, that is, equal to or higher than the first threshold discharge temperature Tdh1(═ 105 ℃), the compressor is stopped 21. When the indoor heat exchange temperature Tc is maintained at 55 to 57 ℃ during the indoor heat exchange heating operation, the discharge temperature Td of the compressor 21 is likely to increase, and the discharge pressure is also likely to increase. Therefore, if the discharge temperature Td is above the first threshold discharge temperature Tdh1 lower than the second threshold discharge temperature Tdh2, the compressor 21 is stopped, whereby the discharge pressure of the compressor 21 can be effectively suppressed from exceeding the upper limit value of the usage range.
The indoor heat exchange heating operation time protection control also includes a stop of the compressor 21 based on the outdoor heat exchange temperature Te that is not included in the heating operation time protection control. It is considered that the indoor heat exchange heating operation of the present invention is often performed in summer when the cooling operation is performed in which the possibility of mold and bacteria growth due to dew condensation water generated in the indoor heat exchanger 31 is high. Since the outdoor air temperature To is high in summer and the outdoor air temperature To is high, the outdoor heat exchange temperature Te of the outdoor heat exchanger 23 functioning as an evaporator increases during the indoor heat exchange heating operation. In this case, since the outdoor heat exchange temperature Te becomes high, there is a possibility that the suction pressure of the compressor 21 increases. Therefore, in the protection control during the indoor heat exchange heating operation, if the outdoor heat exchange temperature Te is equal to or higher than the threshold outdoor heat exchange temperature Teh, the compressor 21 is stopped, and the suction pressure of the compressor 21 is suppressed from increasing, whereby the compression ratio of the compressor 21 can be suppressed from falling below the lower limit of the usage range.
< operation of wetting control >
In the present invention, before the indoor heat exchange heating operation, the humidification control operation may be performed as follows. The humidification control operation is to control the indoor heat exchange temperature based on the temperature and humidity of the indoor heat exchanger 31 after the cooling operation so as to humidify the surface of the indoor heat exchanger 31 with a specific amount of dew condensation water. As described above, when the indoor heat exchange temperature is maintained at a high temperature in a state where dew condensation water is present on the surface of the indoor heat exchanger 31, the remaining rate of mold and bacteria present on the surface of the indoor heat exchanger 31 can be greatly reduced. Here, a humidity signal including humidity information of the measured humidity is supplied from an indoor humidity sensor, not shown, that measures the relative humidity in the indoor unit 3 to the sensor input unit 340 of the indoor unit control unit 300 in the indoor unit 3.
As shown in fig. 12, when recognizing the end of the cooling operation, the control unit stops the rotation of the indoor fan 32 in ST 137. The standstill of the indoor fan 32 suppresses evaporation of dew water from the surface of the indoor heat exchanger 31. At this time, the four-way valve 22 maintains the position during the cooling operation. In ST137, the control unit may reduce the rotation speed of the indoor fan 32 or perform intermittent rotation in addition to stopping the rotation of the indoor fan 32. The rotation of the indoor fan 32 may be appropriately adjusted according to the amount of the dew condensation water.
In ST138, the control unit determines the wetting amount of the indoor heat exchanger 31 based on the amount of dew condensation water generated on the surface of the indoor heat exchanger 31. When determining the amount of humidification, the control unit estimates the amount of saturated water vapor from the output signals of the indoor temperature sensor 75 and the indoor humidity sensor. The control unit determines the amount of dew condensation water based on the estimated saturated steam amount and the values of the duration and elapsed time measured by a timer (not shown) incorporated in the indoor unit 3. In general, the temperature of the indoor heat exchanger 31 is low after the cooling operation, and dew condensation water is generated on the surface of the indoor heat exchanger 31.
If the estimated amount of humidification is less than the predetermined amount, the control unit cools the indoor heat exchanger 31 in ST 139. When cooling the indoor heat exchanger 31, the control unit instructs the operation of the expansion valve 24 and the compressor 21 for lowering the evaporation temperature of the refrigerant in the indoor heat exchanger 31. As a result, the temperature of the indoor heat exchanger 31 is lowered, and the generation of dew condensation water is promoted. Sufficient wetting is ensured on the surface of the indoor heat exchanger 31. The predetermined amount of the wetting amount may be set to an amount of water that does not lose the effectiveness of the wet heat sterilization by evaporation in the heating of the indoor heat exchanger 31, so that the wet heat sterilization can be performed in which the bacteria and mold can be killed and the number of bacteria can be reduced at a temperature lower than that in the dry state by heating the bacteria and mold in a high humidity state.
If the estimated wetting amount reaches a predetermined prescribed amount, the control unit heats the indoor heat exchanger 31 in ST 140. The condensation of the refrigerant is used for heating the indoor heat exchanger 31. At this time, the control unit performs switching of the four-way valve 22. The four-way valve 22 is switched to the position for the heating operation. Here, the temperature of the indoor heat exchanger 31 during heating is set to 45 degrees celsius or higher. Preferably, the temperature of the indoor heat exchanger 31 is set to 60 degrees celsius or higher. Thus, the indoor heat exchanger 31 is heated without going through the drying operation that has been performed conventionally, and the dew condensation water is not evaporated on the surface of the indoor heat exchanger 31. The dew condensation water is heated by the indoor heat exchanger 31. In the heated dew water, bacteria and mold are heated. Therefore, bacteria and mold are sterilized by moist heat. Can kill bacteria and mold and reduce their amount.
In particular, when the temperature of the indoor heat exchanger 31 is set to 45 degrees celsius or higher, the dew condensation water is heated to 45 degrees celsius or higher, and the moist heat sterilization of bacteria and mold is effectively achieved. In addition, when the temperature of the indoor heat exchanger 31 is set to 60 degrees celsius or higher, the moist heat sterilization of bacteria and mold can be more effectively achieved. The sterilization time is shortened. However, in order to suppress evaporation of dew condensation water as much as possible, it is desirable that the temperature of the indoor heat exchanger 31 is set to a temperature as low as possible at 70 ℃. In the dry state of the heat exchanger, even if the temperature is set to 45 degrees celsius or higher, sterilization of bacteria and mold cannot be achieved.
During heating of the indoor heat exchanger 31, the opening degree of the expansion valve 24 and the rotations of the fans 27 and 32 may be appropriately adjusted so that the temperature of the indoor heat exchanger 31 does not exceed 60 degrees, which may be an overload condition.
In ST141, the control unit determines the completion of the moist heat sterilization. At the time of judgment, for example, the control unit uses a timer clock. The timer measures the duration of the set temperature. When the duration of the set temperature reaches a prescribed value, the control unit ends the moist heat sterilization. If the duration of the set temperature is less than a predetermined value, the control unit continues the heating operation. The predetermined value of the duration of the set temperature may be equal to or longer than the time for obtaining the effect of moist heat sterilization. Experiments by the applicant revealed that the effect of moist heat sterilization can be obtained by setting 3 minutes or more for coliform bacteria and 5 minutes or more for melanomyces. In addition, it is found that legionella is preferably 10 minutes or more. At this time, the control unit monitors the operation of the compressor 21 in ST 142. When the overload of the compressor 21 is detected at the time of heating before the set temperature, the control unit lowers the discharge temperature of the compressor 21 and ends the heating operation in ST 7. If no overload is detected, the heating operation is continued until completion of the moist heat sterilization is judged in ST 141.
Here, the overload condition of the compressor 21 set at the time of condensation is relaxed compared with the overload condition of the compressor 21 set at the time of heating operation. That is, the discharge temperature that becomes the threshold value of the overload condition is set high, or the time until the overload protection operation is performed when the discharge temperature exceeds the threshold value of the overload condition for a predetermined time is set long. Since the overload condition of the compressor 21 is relaxed at the time of the humidification control operation, the indoor heat exchanger 31 can be heated to a high temperature as compared to that at the time of the heating operation. The moist heat sterilization of bacteria and mold is realized.
In the humidification control operation of the air conditioner 1, the drying process in the indoor unit 3 may be performed following the moist heat sterilization process. In this drying process, the rotation of the indoor fan 32 is started while the heating of the indoor heat exchanger 31 is maintained. Upon a rotational action of the indoor fan 32, the control unit determines the rotational speed of the indoor fan 32. The rotation of the indoor fan 32 promotes the evaporation of the heated dew condensation water. At this time, the outlet of the indoor unit 3 may be closed by the up-down wind direction plate 35. When the air outlet is closed, the control means may specify the minimum angle of the up-down wind direction plate 35. This can prevent warm air from being blown out after cooling operation. By continuing the drying and heating in this way following the moist heat sterilization, the growth of bacteria and mold remaining in the moist heat sterilization is suppressed.

Claims (9)

1. An air conditioner having: an indoor unit having an indoor heat exchanger and an indoor heat exchange temperature sensor that detects an indoor heat exchange temperature that is a temperature of the indoor heat exchanger; an outdoor unit having a compressor; and a control unit that controls the compressor, the air conditioner being characterized in that, the control unit executes a first protection control executed during a heating operation or a second protection control executed during an indoor heat exchange heating operation in which the indoor heat exchange temperature is maintained at 45 ℃ or higher and less than 59 ℃ that reduces the number of mold and bacteria present in the indoor heat exchanger, when the indoor heat exchanger is caused to function as a condenser, executing the first protection control if the indoor heat exchange temperature reaches a temperature higher than a prescribed first threshold indoor heat exchange temperature, if the indoor heat exchange temperature reaches a temperature higher than a prescribed second threshold indoor heat exchange temperature, the second protection control is executed, and the prescribed second threshold indoor heat exchange temperature is higher than the first threshold indoor heat exchange temperature.
2. The air conditioner according to claim 1,
the second threshold indoor heat exchange temperature is a temperature higher than a target temperature of the indoor heat exchange temperature at the time of the indoor heat exchange heating operation.
3. The air conditioner according to claim 1 or 2,
the control unit may stop the heating operation if the indoor heat exchange temperature reaches a temperature higher than the first threshold indoor heat exchange temperature in the first protection control, and stop the indoor heat exchange heating operation if the indoor heat exchange temperature reaches a temperature higher than the second threshold indoor heat exchange temperature in the second protection control.
4. The air conditioner according to claim 1 or 2,
the outdoor unit includes a discharge temperature sensor that detects a discharge temperature that is a temperature of the refrigerant discharged from the compressor, and executes the second protection control if the discharge temperature reaches a temperature higher than a predetermined first threshold discharge temperature in addition to the indoor heat exchange temperature, and executes the first protection control if the discharge temperature reaches a predetermined second discharge temperature higher than the first threshold discharge temperature in addition to the indoor heat exchange temperature.
5. The air conditioner according to claim 4,
the outdoor unit includes an outdoor heat exchanger and an outdoor heat exchange temperature sensor that detects an outdoor heat exchange temperature that is a temperature of the outdoor heat exchanger, and the second protection control is executed if the outdoor heat exchange temperature reaches a temperature higher than a predetermined threshold outdoor heat exchange temperature in addition to the indoor heat exchange temperature and the discharge temperature.
6. The air conditioner according to claim 4,
the outdoor unit has an outside air temperature sensor that detects an outside air temperature, and the second protection control is also executed if the outside air temperature reaches a temperature higher than a prescribed threshold outside air temperature, in addition to the indoor heat exchange temperature, the discharge temperature, and the outdoor heat exchange temperature.
7. The air conditioner according to claim 3,
the compressor is stopped during the stop of the heating operation in the first protection control and the stop of the indoor heat exchange heating operation in the second protection control.
8. The air conditioner according to claim 1,
when the indoor heat exchange heating operation is performed, the control unit heats the indoor heat exchanger and does not evaporate dew condensation water on the surface of the indoor heat exchanger.
9. The air conditioner according to claim 8,
the control unit performs a wetting control operation for causing the indoor heat exchanger to function as an evaporator to wet a surface of the indoor heat exchanger with a specific amount of dew condensation water before the indoor heat exchange heating operation.
CN201880014547.3A 2017-02-28 2018-02-22 Air conditioner Active CN110382970B (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP2017036408A JP6824779B2 (en) 2017-02-28 2017-02-28 Antifungal method of air conditioner and air conditioner using it
JP2017-036408 2017-02-28
JP2017-184926 2017-09-26
JP2017184926A JP6399181B1 (en) 2017-09-26 2017-09-26 Air conditioner
PCT/JP2018/006448 WO2018159446A1 (en) 2017-02-28 2018-02-22 Air conditioner

Publications (2)

Publication Number Publication Date
CN110382970A CN110382970A (en) 2019-10-25
CN110382970B true CN110382970B (en) 2021-06-08

Family

ID=63371216

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201880014547.3A Active CN110382970B (en) 2017-02-28 2018-02-22 Air conditioner

Country Status (4)

Country Link
EP (1) EP3591306A4 (en)
CN (1) CN110382970B (en)
AU (1) AU2018228986B2 (en)
WO (1) WO2018159446A1 (en)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6656472B1 (en) * 2018-10-16 2020-03-04 日立ジョンソンコントロールズ空調株式会社 Air conditioner
JP7247594B2 (en) * 2019-01-18 2023-03-29 株式会社富士通ゼネラル air conditioner
JP7031651B2 (en) * 2019-12-23 2022-03-08 株式会社富士通ゼネラル Air conditioner
JP7031650B2 (en) * 2019-12-23 2022-03-08 株式会社富士通ゼネラル Air conditioner
CN111397128A (en) * 2020-03-27 2020-07-10 广东美的制冷设备有限公司 High-temperature sterilization method, frequency control method and air conditioner
CN111380152B (en) * 2020-03-27 2021-12-17 广东美的制冷设备有限公司 High-temperature sterilization control method and device, air conditioner and storage medium
CN113405238A (en) * 2021-06-25 2021-09-17 海信（山东）空调有限公司 Air conditioner sterilization control method and device, air conditioner and storage medium
CN113405233A (en) * 2021-06-25 2021-09-17 海信（山东）空调有限公司 Air conditioner sterilization control method and device, air conditioner and storage medium

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60147046A (en) * 1984-01-11 1985-08-02 Matsushita Refrig Co Defrosting control device of heat pump type air conditioner
JPH0490453A (en) * 1990-08-01 1992-03-24 Daikin Ind Ltd Freezer operation control device
JP2006125801A (en) * 2004-11-01 2006-05-18 Matsushita Electric Ind Co Ltd Air conditioner and operation method therefor
JP2006138545A (en) * 2004-11-12 2006-06-01 Matsushita Electric Ind Co Ltd Air conditioner, and its operation method
CN101526257A (en) * 2009-03-26 2009-09-09 宁波海诚电器有限公司 Method for protecting compressor when air conditioner makes heat in high temperature environment
JP2013083437A (en) * 2012-12-26 2013-05-09 Mitsubishi Electric Corp Air conditioning apparatus and safety management method for the same
JP5505540B2 (en) * 2013-04-30 2014-05-28 ダイキン工業株式会社 Air conditioner
CN105180359A (en) * 2015-09-02 2015-12-23 珠海格力电器股份有限公司 Control method and device for preventing high temperature, and air conditioner
CN105987484A (en) * 2015-02-28 2016-10-05 青岛海尔空调器有限总公司 Defrosting control method and system used during heating frequent high-temperature prevention protection of air conditioner

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06129656A (en) * 1992-08-11 1994-05-13 Osaka Gas Co Ltd Air conditioning device with fungs prevention function
JPH1062000A (en) 1996-08-20 1998-03-06 Fujitsu General Ltd Air conditioner
JP2000213795A (en) * 1999-01-25 2000-08-02 Daikin Ind Ltd Air conditioner
CN104913429B (en) * 2014-03-10 2018-04-13 广东美的制冷设备有限公司 Air conditioner method for disinfection and air conditioner
JP2016065687A (en) 2014-09-25 2016-04-28 パナソニックＩｐマネジメント株式会社 Air conditioner

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60147046A (en) * 1984-01-11 1985-08-02 Matsushita Refrig Co Defrosting control device of heat pump type air conditioner
JPH0490453A (en) * 1990-08-01 1992-03-24 Daikin Ind Ltd Freezer operation control device
JP2006125801A (en) * 2004-11-01 2006-05-18 Matsushita Electric Ind Co Ltd Air conditioner and operation method therefor
JP2006138545A (en) * 2004-11-12 2006-06-01 Matsushita Electric Ind Co Ltd Air conditioner, and its operation method
CN101526257A (en) * 2009-03-26 2009-09-09 宁波海诚电器有限公司 Method for protecting compressor when air conditioner makes heat in high temperature environment
JP2013083437A (en) * 2012-12-26 2013-05-09 Mitsubishi Electric Corp Air conditioning apparatus and safety management method for the same
JP5505540B2 (en) * 2013-04-30 2014-05-28 ダイキン工業株式会社 Air conditioner
CN105987484A (en) * 2015-02-28 2016-10-05 青岛海尔空调器有限总公司 Defrosting control method and system used during heating frequent high-temperature prevention protection of air conditioner
CN105180359A (en) * 2015-09-02 2015-12-23 珠海格力电器股份有限公司 Control method and device for preventing high temperature, and air conditioner

Also Published As

Publication number Publication date
CN110382970A (en) 2019-10-25
AU2018228986A1 (en) 2019-08-22
WO2018159446A1 (en) 2018-09-07
AU2018228986B2 (en) 2021-02-25
EP3591306A4 (en) 2020-12-23
EP3591306A1 (en) 2020-01-08

Similar Documents

Publication Publication Date Title
CN110382970B (en) Air conditioner
WO2018159444A1 (en) Air conditioner
JP6447693B1 (en) Air conditioner
JP6399181B1 (en) Air conditioner
EP3591305B1 (en) Mold prevention method for air conditioner
CN111356881B (en) Air conditioner and control method thereof
CN105972764A (en) Sterilization method and device and air conditioner
CN110207313A (en) Air conditioner and its air conditioning control method, control device and readable storage medium storing program for executing
JP4003101B2 (en) Control method and apparatus for air conditioner
JP6200241B2 (en) Drying equipment
CN110332654A (en) Air-conditioning system and air-conditioning system defrosting control method
JP2019060527A (en) Air conditioner
JP6942082B2 (en) Integrated air conditioner
JP5266951B2 (en) Clothes dryer
JP2012207811A (en) Air conditioner
KR20040055628A (en) Method for controlling air conditioner
JP4987102B2 (en) Dehumidifier
JP3963196B2 (en) Air conditioner control device
JP2021045330A (en) Clothes dryer
JP7113775B2 (en) Antifungal method for air conditioner and air conditioner using the same
JPH051839A (en) Controller of air-conditioner
JP6932002B2 (en) Air conditioner
JP2005164114A (en) Bathroom air conditioning system
JP2765667B2 (en) Control device for air conditioner
WO2021038744A1 (en) Air conditioner

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant