JP4043183B2 - Air conditioner - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a refrigeration apparatus (air conditioning apparatus), and more particularly to control of a crankcase heater of a compressor.
[0002]
[Prior art]
Conventionally, in an air conditioner, when the compressor is stopped and the internal temperature of the compressor is low, the refrigerant dissolves in the lubricating oil in the compressor, and when the compressor starts operating in that state, Since the liquid refrigerant evaporates, the lubricating oil foams and flows out of the compressor together with the gas refrigerant. As a result, the compressor may be in a poorly lubricated state.
[0003]
Therefore, in the conventional air conditioner, a crankcase heater is installed at the lower part of the compressor, and the crankcase heater is turned ON while the compressor is stopped so that the refrigerant does not mix with the lubricating oil in the compressor. Was considered.
[0004]
As this type of conventional air conditioner, for example, a refrigeration apparatus described in JP 2000-171107 A has been proposed.
[0005]
In this refrigeration system, when the operation of the compressor is stopped, the crankcase heater is energized / powered out based on the outside air temperature to reduce power consumption.
[0006]
[Problems to be solved by the invention]
However, even when the outside air temperature is high, the refrigerant may be dissolved in the lubricating oil in the compressor, and it has not been possible to completely prevent the foamed lubricating oil from flowing out of the compressor.
[0007]
Accordingly, the present invention has been made in consideration of the above-described points, and it is an object of the present invention to provide a highly reliable air conditioner while reducing power consumption while the compressor is stopped.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present invention provides three types of air temperature when the compressor is stopped: high (outside air temperature is GH degree or more), medium (GL degree or more and less than GH degree), and low (less than GL degree). Set the outside air temperature zone, and in each of these temperature zones, the temperature difference obtained by subtracting the room temperature from the outside air temperature is three (greater than SH), middle (more than SL degree and less than SH degree), and small (less than SL degree) temperature. The temperature zone which is divided by the difference zone and the heating means repeats energization / power failure is the case where the outside temperature zone is high and the temperature zone is medium, and the outside temperature zone is medium and the temperature zone is large. The temperature zone in which the means is always energized is a case where the outside air temperature zone is in the middle and the temperature difference zone is in the middle.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a circuit explanatory diagram of an air conditioner showing an embodiment of the present invention.
[0015]
As shown in FIG. 1, the air conditioner 1 includes an outdoor unit 2 and an indoor unit 3, and is configured by connecting a refrigerant pipe 4 of the outdoor unit 2 and a refrigerant pipe 5 of the indoor unit 3. .
[0016]
The outdoor unit 2 is installed outside and stores the equipment described below. Compressor 7, accumulator 6 provided on the suction side of compressor 7, four-way switching valve 8 for switching the flow of refrigerant to compressor 7, outdoor heat exchanger 9, and outdoor expansion valve 10 as a decompression device The (electric valve) and the receiver tank 18 are connected via the refrigerant pipe 4 as shown in the figure. The degree of opening of the outdoor expansion valve 10 is adjusted according to the air conditioning load during heating operation. In the outdoor heat exchanger 9, a fan 9 </ b> F that blows air toward the outdoor heat exchanger 9 and an outdoor air temperature sensor 28 are disposed adjacent to each other.
[0017]
On the other hand, the indoor unit 3 is installed indoors, and an indoor expansion valve 12 (electric valve) is disposed in the vicinity of the indoor heat exchanger 11. The opening of the indoor expansion valve 12 is adjusted according to the air conditioning load during the cooling operation. Further, the indoor heat exchanger 11 is provided with a fan 11F for sucking indoor air into the indoor heat exchanger 11 and an indoor temperature sensor 29 adjacent to each other.
[0018]
Reference numeral 15 denotes a control device as control means, which controls components such as the outdoor expansion valve 10, the indoor expansion valve 12, the outdoor air temperature sensor 28, and the indoor temperature sensor 29.
[0019]
In the air conditioner 1 described above, by switching the four-way switching valve 8, the flow of the refrigerant flowing through the refrigerant pipes 4 and 5 is changed, and the cooling operation or the heating operation is performed.
[0020]
During the cooling operation, the four-way switching valve 8 is switched to the cooling side, and the refrigerant flows through the refrigerant pipes 4 and 5 as indicated by the solid arrows in FIG. 1, the outdoor expansion valve 10 is opened, and the outdoor heat exchanger 9 is turned into the condenser. The indoor expansion valve 12 is controlled so that the indoor heat exchanger 11 becomes an evaporator and cools the room.
[0021]
Further, during the heating operation, the four-way switching valve 8 is switched to the heating side, and the refrigerant flows through the refrigerant pipes 4 and 5 as indicated by the broken arrows in FIG. 1, the outdoor expansion valve 10 is controlled, and the outdoor heat exchanger 9 is the evaporator. Moreover, the indoor expansion valve 12 is opened, and the indoor heat exchanger 11 becomes a condenser to heat the room.
[0022]
Generally, when the internal temperature of the compressor 7 is low or the internal pressure of the compressor 7 is high, the liquid refrigerant is dissolved in the lubricating oil in the compressor 7 while the compressor 7 is stopped, and the compressor 7 Since the liquid refrigerant in the lubricating oil evaporates during the operation, the lubricating oil may foam and flow out of the compressor 7 together with the gas refrigerant.
[0023]
Therefore, the conventional compressor 7 is provided with a crankcase heater 27 as a heating means outside the lower portion thereof. The compressor 7 is energized while the compressor 7 is stopped to heat the inside of the compressor 7. The refrigerant was prevented from dissolving in the lubricating oil.
[0024]
However, in summer, etc., there is a case where the energization operation is not required even when the compressor 7 is stopped. With the recent increase in the energy saving movement, the power supply / power failure of the crankcase heater 27 while the compressor 7 is stopped is controlled. It has been considered to reduce.
[0025]
The details of the embodiment of the present invention will be described with reference to FIG. FIG. 2 is an explanatory diagram for controlling the crankcase heater 27 according to the embodiment of the present invention.
[0026]
The horizontal axis in FIG. 2 represents the outside air temperature, and is divided into three groups: less than GL ° (for example, 10 ° C.), more than GL ° and less than GH ° (for example, 20 ° C.), and more than GH °. The vertical axis in FIG. 2 represents the value obtained by subtracting the room temperature from the outside air temperature, and is divided into three categories: less than SL ° (eg, 2 ° C), greater than SL °, less than SH ° (eg, 6 ° C), and greater than SH °. Has been.
[0027]
When the outside air temperature is less than GL (G) ° or the value obtained by subtracting the room temperature from the outside air temperature is less than SL (S) °, the crankcase heater 27 is always energized.
[0028]
When the outside air temperature is GH (G) ° or more and the value obtained by subtracting the room temperature from the outside air temperature is SH (S) ° or more, the crankcase heater 27 is always out of power.
[0029]
When the outside air temperature is not less than GH ° and the value obtained by subtracting the room temperature from the outside temperature is not less than SL ° and less than SH °, the crankcase heater 27 repeats energization / power failure (for example, 2 hours ON, 1 hour OFF).
[0030]
When the outside air temperature is not less than GL ° and less than GH ° and the value obtained by subtracting the room temperature from the outside air temperature is not less than SH °, the crankcase heater 27 repeats energization / power failure (for example, 2 hours ON, 1 hour OFF).
[0031]
When the outside air temperature is not less than GL ° and less than GH °, and the value obtained by subtracting the room temperature from the outside air temperature is not less than SL ° and less than SH °, the crankcase heater 27 is always energized.
[0032]
As described above, the energization and power failure operation of the crankcase heater 27 are controlled by the control device 15, thereby reducing the power consumption when the compressor 7 is stopped and the reliability without causing the compressor 7 to be in a poorly lubricated state. A highly functional air conditioner can be provided.
[0033]
In addition, this invention is not limited to the Example mentioned above, A various deformation | transformation is possible in the range which does not deviate from the summary of this invention.
[0034]
【The invention's effect】
As described above, the present invention has three outdoor temperature zones in which the outside air temperature when the compressor is stopped is high (the outside air temperature is GH degree or more), medium (GL degree or more and less than GH degree), and low (less than GL degree). In each of these temperature zones, the temperature difference obtained by subtracting the room temperature from the outside air temperature is large (SH or more), medium (SL degree or more and less than SH degree), and small (less than SL degree). The temperature zone in which the heating means repeats energization / power failure is when the outside air temperature zone is high and the temperature difference zone is medium, and the outside air temperature zone is medium and the temperature difference zone is large. Since the energized temperature zone is a case where the outside air temperature zone is medium and the temperature difference zone is middle, it is possible to reduce the power consumption while the compressor is stopped and to provide a highly reliable air conditioner.
[Brief description of the drawings]
FIG. 1 is a circuit explanatory diagram of an air conditioner showing an embodiment of the present invention.
FIG. 2 is a control explanatory view of a crankcase heater showing an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2 Outdoor unit 3 Indoor unit 7 Compressor 8 Four-way selector valve 9 Outdoor heat exchanger 11 Indoor heat exchanger 15 Controller 27 Crankcase heater 28 Outside temperature sensor 29 Indoor temperature sensor

Claims (1)

In an air conditioner including a compressor for increasing the pressure of refrigerant and a heating means for evaporating liquid refrigerant in the compressor, the outside air temperature is high when the compressor is stopped (outside air temperature is GH degree or more), Three outside air temperature zones (GL degree or more and less than GH degree) and low (less than GL degree) are set, and the temperature difference obtained by subtracting the room temperature from the outside air temperature in each temperature zone is large (SH or more), medium ( It is divided into three temperature difference zones: SL degree or more and less than SH degree, and small (less than SL degree).
The temperature zone in which the heating means repeats energization / power failure is a case where the outside air temperature zone is high and the temperature difference zone is medium, as well as the outside air temperature zone is medium and the temperature difference zone is large,
The air conditioner characterized in that the temperature zone in which the heating means is always energized is a case where the outside air temperature zone is inside and the temperature difference zone is inside .

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