JP4572470B2 - Operation control method of air conditioner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an operation control method for an air conditioner, and more particularly to a control method at the time of switching from a cooling operation to a dry operation.
[0002]
[Prior art]
In recent air conditioners, demand as a dehumidifying function has been further expanded, and higher performance of dehumidification is required. Air that can achieve the comfort of the living environment, requires an even higher-performance air conditioner, and can reliably perform "isothermal drying-reducing only humidity without lowering room temperature" as one element of comfort. The development of harmonic machines is progressing. In particular, Japanese Patent Laid-Open No. 6-137712 has been disclosed as means for improving the comfort of the living environment during dry driving. The reheat drying method used as means for achieving the “isothermal drying” includes a heater reheat drying method provided with a heating element such as a heater, an evaporation unit (= cooler) and a condensing unit (on the indoor unit side). There are two main types, the cycle reheat dry method with a reheater), but the latter cycle reheat dry method is the mainstream from the viewpoint of comfort and power consumption.
[0003]
The problem with the cycle reheat drying method is that the sensible heat capacity is insufficient compared to the normal cooling operation due to the reduced number of cooling parts in the indoor heat exchanger, especially when the temperature difference between the inside and outside is large. It has become larger, making it difficult to drive comfortably in cycle dry. As a countermeasure, a method is known in which the air flow rate of the outdoor heat exchanger is increased to lower the condensation temperature in the indoor reheat section to increase the sensible heat capacity (= cold operation). A method of reducing the condensation temperature in the reheat part by constricting the electronic expansion valve outside the room uniformly when the temperature is high is also considered.
[0004]
[Problems to be solved by the invention]
However, in the above-described means, when switching from the cooling operation to the dry operation, the water retained in the indoor heat exchanger is heated by the first heat exchanger (reheater), re-evaporates, and the air passing through the fan The humidity reached almost 100%, and there was a problem that spraying and fan condensation occurred.
[0005]
The present invention solves the above-mentioned problem. Before switching to cycle reheat dry operation, the amount of water retained in the indoor heat exchanger is reduced, so that the operation range in which dry operation is possible (wide indoor temperature, indoor relative humidity) is increased. The object is to provide an operation control method for an air conditioner that can be expanded.
[0006]
[Means for Solving the Problems]
In the present invention, an indoor heat exchanger and an indoor fan, a compressor, a four-way valve, an outdoor heat exchanger and an outdoor fan, and a pulse electronic expansion valve constitute a refrigeration cycle, and the indoor heat exchanger is the first during dry operation. the heat exchanger have you (the reheater) and the second heat exchanger (cooler) and via a pressure reducing device separating the air conditioner having dehumidification function of reheating method comprising communicating, cooling When switching from operation to dry operation, the compressor is first stopped for a predetermined period of time, followed by low-frequency warm- air dry operation for a predetermined period of time, and then warm-air Cooling and dry operation that controls the opening degree of the pulse-type electronic expansion valve as the difference between the operation and the isothermal dry operation in which the room air is heated to the same level as the room temperature and blown out, and the difference between the room temperature and the set temperature is larger real dry operation by selecting one of the operation It is intended to control to.
[0007]
This configuration prevents the condensation of the spray and the indoor fan in dry operation, possible operating range (wide indoor temperature, indoor relative humidity) of the dry operation Ru can be extended.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a refrigeration cycle diagram of the air conditioner of the present invention. In FIG. 1, 1 is a compressor, and a four-way valve 2, an indoor heat exchanger 3, a pulse-type electronic expansion valve 4, and an outdoor heat exchanger 5 are sequentially connected to form a heat pump type refrigeration cycle.
[0009]
The indoor heat exchanger 3 includes a first heat exchanger (reheater) 6, a second heat exchanger (cooler) 7, an electromagnetic valve 8, and a capillary pressure reducing device 9. One heat exchanger 6 and the second heat exchanger 7 are communicated with each other through an electromagnetic valve 8, and a capillary pressure reducing device 9 is disposed in parallel with the electromagnetic valve 8.
[0010]
An indoor fan 10 that ventilates the indoor heat exchanger 3 and an outdoor fan 11 that ventilates the outdoor heat exchanger 5 are provided.
[0011]
Reference numeral 12 denotes a control unit that controls the rotational speeds of the indoor fan 10, the outdoor fan 11, and the compressor 1, together with the drive control circuits 13 and 14 and the inverter circuit 15, and the opening degree of the expansion valve 4. Are controlled, and an indoor temperature sensor 16 for detecting the indoor temperature, an outside air temperature sensor 17 for detecting the outside air temperature, a cooler pipe temperature sensor 18 for detecting the pipe temperature of the second heat exchanger 7, and air conditioning. A wireless remote controller (not shown) provided with a machine operation stop means, a temperature adjusting means for setting the room temperature, and the like is connected.
[0012]
Next, the air conditioning operation of the air conditioner configured as described above will be described.
[0013]
During the cooling operation, the electromagnetic valve 8 is controlled to be fully opened, and the refrigerant sucked and compressed by the compressor 1 is sent to the outdoor heat exchanger 5 through the four-way valve 2 where it is condensed and liquefied. The refrigerant leaving the outdoor heat exchanger 5 is decompressed by the expansion valve 4 and guided to the first heat exchanger 6. The refrigerant that has left the first heat exchanger 6 passes through the fully-open electromagnetic valve 8 and flows into the second heat exchanger 7. In each of the heat exchangers 6 and 7, the refrigerant evaporates and takes the latent heat of evaporation from the room air and vaporizes it. Then, the refrigerant that has passed through the heat exchangers 6 and 7 is again sucked into the compressor 1 through the four-way valve 2.
[0014]
During the heating operation, the electromagnetic valve 8 is controlled to be fully opened, and the refrigerant sucked and compressed by the compressor 1 is sent to the second heat exchanger 7 through the four-way valve 2. The refrigerant that has left the second heat exchanger 7 passes through the fully-open electromagnetic valve 8 and flows into the first heat exchanger 6. In each of the heat exchanges 6 and 7, the refrigerant condenses and liquefies by releasing heat of condensation to the indoor air. Then, the refrigerant that has passed through the heat exchangers 6 and 7 is decompressed by the expansion valve 4 and guided to the outdoor heat exchanger 5. Here, the refrigerant takes the latent heat of evaporation from the outdoor air and vaporizes it, and is again sucked into the compressor 1 through the four-way valve 2.
[0015]
During the dry operation, the electromagnetic valve 8 is controlled to be fully closed, and the refrigerant sucked and compressed by the compressor 1 is sent to the outdoor heat exchanger 5 through the four-way valve 2, and further, the expansion valve 4 in the fully open state. Then, the first heat exchanger 6 is led. The refrigerant is condensed and liquefied by the outdoor heat exchanger 5 and the first heat exchanger (reheater) 6, and at this time, the first heat exchanger 6 releases the heat of condensation to the indoor air. Since the electromagnetic valve 8 is closed, the liquid refrigerant is decompressed by the capillary decompression device 9 and flows into the second heat exchanger (cooler) 7. In the second heat exchanger 7, the refrigerant evaporates and takes the latent heat of vaporization from the indoor air and vaporizes it. At this time, the indoor air is dehumidified to lower the indoor humidity. Then, the refrigerant exiting the second heat exchanger 7 is again sucked into the compressor 1 through the four-way valve 2.
[0016]
The second heat exchanger 7 functions as a cooler that dehumidifies and cools the indoor air sucked from the air inlet of the air conditioner, and the first heat exchanger 6 heats the dehumidified and cooled room air. It becomes a reheater. That is, it is dehumidified by being blown into the room as dry air.
[0017]
When the room air is lower than the set temperature of the remote controller, the warm and dry operation is selected. In this warm and dry operation, the outdoor fan 11 is operated at an extremely low rotational speed. As a result, the heat radiation of the refrigerant in the outdoor heat exchanger 5 is reduced, the amount of heat applied to the first heat exchanger 6 that functions as a reheater is increased, and the dehumidified and cooled dry air is sufficiently warmed to be indoors. Is blown out.
[0018]
Further, when the room air is close to the set temperature of the remote controller, the isothermal dry operation is selected. In this isothermal dry operation, the outdoor fan 11 is operated at an extremely low rotational speed. As a result, the heat radiation of the refrigerant in the outdoor heat exchanger 5 is reduced, and the dry air is heated to the same level as the room temperature and blown into the room.
[0019]
Further, when the room air is higher than the set temperature of the remote controller, the cool dry operation is selected. In this cold and dry operation, the outdoor fan 11 is operated at an extremely low rotational speed. Further, the larger the difference between the room temperature and the set temperature of the remote controller, the smaller the opening degree of the expansion valve 4 is controlled, thereby lowering the condensation temperature of the first heat exchanger 6 and sensible heat capacity. the it is to be secured.
[0020]
Next, an embodiment of the control method in the air conditioner having the above configuration will be described with reference to the drawings.
[0021]
(Embodiment 1)
Embodiment 1 of the present invention will be described with reference to FIG.
[0022]
After the cooling operation (operation frequency F1), the compressor is stopped for a certain time (N1), the low-frequency (F3) warm-air dry operation is performed for a certain time (N2), and then the cycle dry operation corresponding to the load (operation frequency F2). ).
[0023]
As described above, the invention described in the first embodiment reduces the water retention amount of the indoor heat exchanger before switching to the dry operation. And according to this structure, the spraying at the time of dry operation and the dew condensation to an indoor fan can be prevented, and the driving | operation area | region (wide indoor temperature and indoor relative humidity) in which dry operation is possible can be expanded.
[0024]
(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIG.
[0025]
After the cooling operation (operation frequency F1), the compressor is stopped, the indoor air blowing operation is performed for a certain time (N3), and then the cycle dry operation (operation frequency F2) corresponding to the load is performed.
[0026]
Thus, the invention described in the second embodiment is such that the water retention amount of the indoor heat exchanger is gradually reduced before switching to the dry operation. And according to this structure, the spraying at the time of dry operation and the dew condensation to an indoor fan can be prevented, and the operation area | region (wide indoor temperature and indoor relative humidity) in which dry operation is possible can be expanded further.
[0027]
(Embodiment 3)
Embodiment 3 of the present invention will be described with reference to FIG.
[0028]
After cooling operation (operation frequency F1), the compressor is stopped for a certain time (N1), heating operation (operation frequency F4) is performed for a certain time (N4), then the compressor is stopped for a certain time (N1), and then the load is It shifts to a considerable cycle dry operation (operation frequency F2).
[0029]
As described above, the invention described in the third embodiment is designed to reduce the water retention amount of the indoor heat exchanger at once before switching to the dry operation. And according to this structure, the spraying at the time of dry operation and the dew condensation to an indoor fan can be prevented, and the operation area | region (wide indoor temperature and indoor relative humidity) in which dry operation is possible can be expanded further.
[0030]
【The invention's effect】
As is apparent from the above embodiment, the invention described in claim 1 prevents the spraying and condensation on the indoor fan during the dry operation by reducing the amount of water retained in the indoor heat exchanger before switching to the dry operation. Te, possible operating range (wide indoor temperature, indoor relative humidity) for dry operation as possible out to widen the.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a refrigeration cycle of an air conditioner of the present invention. FIG. 2 is a control diagram showing a first embodiment of the invention. FIG. 3 is a control diagram showing a second embodiment of the invention. Control diagram showing embodiment 3 of the invention
DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Indoor heat exchanger 4 Expansion valve 5 Outdoor heat exchanger 6 1st heat exchanger (reheater)
7 Second heat exchanger (cooler)
8 Solenoid valve 9 Pressure reducing device 10 Indoor fan 11 Outdoor fan 12 Control unit 13, 14 Drive control circuit 15 Inverter circuit 16 Indoor suction temperature sensor 17 Outdoor suction temperature sensor 18 Cooler piping temperature sensor F1 Cooling operation frequency F2 Dry operation frequency F3 Low Frequency of warm air dry operation frequency F4 Heating operation frequency N1 Compressor stop time N2 Low frequency warm air dry operation time N3 Fan operation time N4 Heating operation time

Claims (2)

An indoor heat exchanger and an indoor fan, a compressor, a four-way valve, an outdoor heat exchanger and an outdoor fan, and a pulse-type electronic expansion valve constitute a refrigeration cycle, and the indoor heat exchanger is the first heat exchanger during dry operation In an air conditioner having a reheating type dehumidifying function that is separated into a (reheater) and a second heat exchanger (cooler) and communicates with each other via a pressure reducing device, from a cooling operation to a dry operation. At the time of switching, the compressor is first stopped for a predetermined time, and then a low-frequency warm- air dry operation is performed for a predetermined time. Either isothermal dry operation in which air is warmed to the same extent as the room temperature and blown out, or cold air dry operation in which the opening degree of the pulse-type electronic expansion valve is controlled to be smaller as the difference between the room temperature and the set temperature is larger select implementing dry operation Operation control method of an air conditioner characterized by comprising a means for cormorants control. It controls using the control method of the air conditioner of Claim 1 , The air conditioner characterized by the above-mentioned.

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