JP2000257963A - Refrigerating cycle apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve restartability, immediately after a motor driven compressor is stopped, without using an equalizing valve by providing a control means for operating a motor driven fan, even after the compressor has stopped. SOLUTION: When an air conditioner switch 9 is closed, a motor driven fan 3 and a blower fan 6 are operated based on a command from an air conditioning controller 8, and an inverter 10 applies an AC voltage to a motor portion 103 of a motor driven compressor 1. The portion 103 receives its voltage and drives a compressor mechanism section 100. The mechanism section 100 sucks and compresses a refrigerant, and discharges the refrigerant to a condenser 2 side. A gas refrigerator fed under pressure to the condenser 2 is heat exchange with an atmosphere fed under pressure by a motor driven fan 3, condensed, liquefied, and pressure reduced by a pressure reducing unit 4 to become a vapor- liquid phase, and the vapor-liquid phase refrigerant is fed to an evaporator 5. The evaporator 5 heat exchanges the vapor-liquid phase refrigerant with air condensed air supplied by the fan 6 to cool in a compartment by the cooled conditioned air.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in the startability of an electric compressor in a refrigeration cycle apparatus, and is particularly suitable for use in an air conditioner of a vehicle (electric vehicle).

[0002]

2. Description of the Related Art In a vehicle refrigeration cycle device (air conditioner), an air conditioner switch of an air conditioner may be turned on immediately after being turned off by an occupant. In this case, the compressor is temporarily stopped and then restarted. Since the time required for starting the compressor is short, the compressor driving load is particularly large, and the restart cannot be performed in some cases in relation to the capacity of the compressor driving motor.

Therefore, in order to reduce the load at the time of starting the compressor, conventionally, in a refrigeration cycle device (refrigerator) for a home appliance having an electric compressor, the high pressure side and the low pressure side of the refrigeration cycle are communicated by an equalizing valve. In addition to equalizing the pressure, the rotational speed of the compressor is gradually increased to the rated rotational speed over several tens of seconds. On the other hand, Japanese Patent Application Laid-Open No. 57-92677
In the refrigerating cycle device (refrigerator) described in Japanese Patent Application Laid-Open Publication No. H11-27139, when the electric compressor is started, when the internal temperature is high, the number of heat exchanges in the evaporator is reduced by lowering the rotation speed of the cooling air circulation fan. There has been proposed an apparatus that suppresses a rise in pressure in a cycle and suppresses a peak of a load that occurs after the compressor is started.

[0004]

However, in the former conventional device, the restartability immediately after the compressor is stopped is improved by the function of the pressure equalizing valve. There is a problem that it becomes complicated. On the other hand, according to the invention described in the above publication, the load after the compressor is started can be suppressed, but the load at the initial stage of the compressor start cannot be suppressed, so that the restartability immediately after the compressor is stopped is sufficiently improved. It is not possible.

[0005] In view of the above, it is an object of the present invention to improve restartability immediately after a compressor is stopped without using a pressure equalizing valve.

[0006]

In order to achieve the above object, according to the present invention, an electric compressor (1) for compressing and discharging a refrigerant, and a refrigerant discharged from the electric compressor (1) are provided. In a refrigeration cycle apparatus including a condenser (2) for condensing water and an electric fan (3) for sending cooling air to the condenser (2), the electric fan (3) is operated even after the electric compressor (1) is stopped. Is provided with control means (8) for operating.

[0007] According to this, the refrigerant in the condenser (2) can be cooled immediately after the stop of the electric compressor (1), and the high-pressure side pressure of the refrigeration cycle can be rapidly reduced. , The time required for restarting after stopping is reduced, and the restartability can be improved. In addition, since a pressure equalizing valve is not required, it can be implemented at a low cost with an extremely simple configuration.

[0008] The invention according to claim 2 is characterized in that at least one of the operation time of the electric fan (3) and the air blowing amount is controlled according to a physical quantity related to the high pressure side pressure of the refrigeration cycle. According to this, when the high-pressure side pressure is low, the operation time of the electric fan (3) or the amount of air blow can be reduced or set to zero, and the power consumption can be reduced.

According to a third aspect of the present invention, at least one of the operating time of the electric fan (3) and the amount of air blow is reduced as the outside air temperature decreases.
According to this, when the outside air temperature is low and the air can be expected to rapidly cool the refrigerant in the condenser (2), the operation time of the electric fan (3) or the blowing amount is reduced or set to zero to reduce the power consumption. Can be reduced.

According to a fourth aspect of the present invention, there is provided a refrigeration cycle apparatus mounted on a vehicle, wherein at least one of an operation time and an air blowing amount of the electric fan (3) is reduced as the traveling speed of the vehicle increases. It is characterized by having According to this, in a vehicle speed range in which rapid cooling of the refrigerant in the condenser (2) can be expected due to the traveling wind, the operating time of the electric fan (3) or the blowing amount is reduced or set to zero.
Power consumption can be reduced.

The reference numerals in parentheses of the above means indicate the correspondence with the specific means described in the embodiments described later.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; FIG. 1 shows an example in which a refrigeration cycle device according to an embodiment of the present invention is applied to an air conditioner of a vehicle (electric vehicle). The electric compressor 1 sucks a gas refrigerant from an inlet 101 and compresses the refrigerant. It is composed of a compression mechanism section 100 that discharges from the rear discharge port 102 and an electric motor section (AC motor) 103 that drives the compression mechanism section 100, and is installed outside the cabin of the electric vehicle.

Reference numeral 2 denotes a condenser for cooling and condensing the high-pressure gas refrigerant discharged from the electric compressor 1. Reference numeral 3 denotes an electric fan for blowing the condenser 2, and the condenser 2 and the electric fan 3 are installed outside the vehicle compartment. The condenser 2 performs heat exchange between the outside air blown by the electric fan 3 and the refrigerant. 4 is a decompressor (expansion valve) for decompressing the refrigerant condensed in the condenser 2 and 5 is a depressurizer 4
The evaporator 6 evaporates the refrigerant which has been decompressed in the gas-liquid two-phase state, and the electric blower fan 6 blows the air for air-conditioning to the evaporator 5. The evaporator 5 performs heat exchange between the air blown by the blower fan 6 and the refrigerant. The pressure reducer 4 adjusts the mass flow rate of the refrigerant circulating in the refrigeration cycle so that the degree of heating of the refrigerant at the outlet side of the evaporator 5 becomes a predetermined value.

7 is an on-board DC power supply, and 8 is an air-conditioning control device (control means) for controlling the air-conditioning device based on various signals.
, And includes a microcomputer and a peripheral circuit, and includes a timer unit 80. Reference numeral 9 denotes an air conditioner switch of an air conditioner which is disposed near the instrument panel in the vehicle compartment and is operated by an occupant. A signal of the air conditioner switch 9 is input to the air conditioner controller 8.
Turns on the refrigeration cycle and turns off the air conditioner switch 9 to stop the operation of the refrigeration cycle.

In addition to the air conditioner switch 9, the air-conditioning control device 8 has an outside air temperature sensor for detecting the outside air temperature, an inside air temperature sensor for detecting the temperature inside the vehicle, and an air temperature immediately after passing through the evaporator 5. Sensor signals are input from a group of air conditioning sensors including an evaporator temperature sensor for detecting, a solar radiation sensor for detecting the amount of solar radiation into the vehicle compartment, a high pressure side pressure sensor for detecting a high pressure side pressure of a refrigeration cycle, and the like. I have. In addition, signals (temperature setting signals, etc.) from the levers and switches of the air conditioning operation panel provided near the driver's seat in the vehicle cabin are also input to the control device 8.

The air-conditioning control device 8 controls the electric fan 3, the blower fan 6, and the inverter (described later in detail) 10 based on these signals. 10 is the motor unit 1
03 that applies an AC voltage to the
Numeral 0 adjusts the frequency of the AC voltage based on a command from the air-conditioning control device 8, thereby continuously changing the rotation speed of the electric compressor 1.

Next, the operation of this embodiment will be described. When the air conditioner switch 9 is turned on by the occupant, the electric fan 3 and the blower fan 6 operate based on a command from the air conditioning control device 8, and the inverter 10 applies an AC voltage to the electric motor unit 103 of the electric compressor 1. . Upon receiving the AC voltage, the electric motor 103 drives the compression mechanism 100, and the compression mechanism 100 sucks and compresses the refrigerant and discharges the refrigerant to the condenser 2 side.

The high-pressure gas refrigerant pumped to the condenser 2 is
It exchanges heat with the outside air blown by the electric fan 3 and is condensed,
The liquefied refrigerant is decompressed by the decompressor 4 to be in a gas-liquid two-phase state and reaches the evaporator 5. In the evaporator 5, the blower fan 6
The heat exchange between the conditioned air blown by the air and the gas-liquid two-phase refrigerant is performed, and the conditioned air thus cooled cools the vehicle interior.

The cooling capacity is controlled by a command from the air-conditioning control device 8 based on the calculation result of the input signal.
The frequency of the AC voltage is adjusted to change the rotation speed of the electric compressor 1 and the rotation speed of the blower fan 6 is switched. Further, the electric fan 3 during the cooling operation is ON-OFF controlled according to the high pressure side pressure and the like.

Next, the operation of the air conditioner when the air conditioner is stopped will be described with reference to FIGS. 2, Pd indicates the high pressure side pressure of the refrigeration cycle, Ps indicates the low pressure side pressure of the refrigeration cycle, and Pdx indicates the level of the high pressure side pressure Pd at which the electric compressor 1 can be started. FIG. 3 shows conventional control and characteristics. When the air conditioner switch 9 is turned off by the occupant, the electric compressor 1 and the electric fan 3 are immediately stopped as shown in FIG. On the other hand, in the present embodiment, when the air conditioner switch 9 is turned off, the electric compressor 1 is immediately stopped. However, the electric fan 3 continues to operate for a predetermined time set by the timer unit 80 even after the air conditioner switch 9 is turned off. The drive is continued for T1 (about 40 seconds in this example).

Thus, the air conditioner switch 9 is turned off.
Thereafter, by forcibly operating the electric fan 3, the refrigerant in the condenser 2 is rapidly cooled, and the high-pressure side pressure Pd is rapidly reduced. Here, the air conditioner switch 9 is turned off.
Comparing the time (restartable time) T2 between the time when the electric compressor 1 is stopped and the high-pressure side pressure Pd decreases to the startable level Pdx, the restartable time T2 is about 60 seconds in the related art. On the other hand, in the case of this embodiment, it was about 8 seconds.

As is apparent from this, according to the present embodiment, the time from when the electric compressor 1 is stopped to when it can be restarted is greatly reduced, and the restartability immediately after the compressor is stopped is improved. Can be done. In addition, since a pressure equalizing valve is not required, it can be implemented at a low cost with an extremely simple configuration. The power consumption is controlled by controlling (decreasing the driving time) the predetermined time T1 set by the timer unit 80, that is, the driving time of the electric fan 3 after the air conditioner switch 9 is turned off in accordance with various parameters as follows. The amount can be reduced.

The electric fan 3 may be stopped when the high-pressure side pressure Pd after the air conditioner switch 9 is turned off decreases to the startable level Pdx, or the electric fan 3 may elapse several seconds after the high pressure side pressure Pd drops to the startable level Pdx. 3 may be stopped. Since the cooling rate of the refrigerant in the condenser 2 changes depending on the outside air temperature, the predetermined time T1 may be continuously changed according to the outside air temperature. At a certain temperature (for example, 35 ° C.) or lower, the electric fan 3 may not be driven (the predetermined time T1 = 0) even after the air conditioner switch 9 is turned off.

Since the refrigerant in the condenser 2 can be cooled by the traveling wind, the predetermined time T1 may be continuously changed according to the traveling speed of the vehicle. Further, the predetermined time T1 may be set to zero at a certain vehicle speed (for example, 10 km / h) or less. In this case, the predetermined time T1 may be determined based on the average vehicle speed immediately before the air conditioner switch 9 is turned off.

The above-described predetermined time T1 may be continuously changed by estimating the high-pressure side pressure Pd from the current value of the electric motor unit 103 immediately before turning off the air conditioner switch 9 or the temperature on the cycle high-pressure side. The predetermined time T1 may be continuously changed by combining the various parameters described above.

In the above description, an example in which the predetermined time T1 is changed according to the outside air temperature or the like has been described.
Instead of changing 1, it is also possible to control the voltage applied to the electric fan 3 to change the amount of air blow, thereby also reducing the power consumption. When the air conditioner switch 9 is turned on immediately after being turned off, the restart of the electric compressor 1 is prohibited until the restartable time T2 elapses, thereby operating the electric compressor 1 under overload conditions. Thus, durability and reliability of the electric compressor 1 can be ensured.

Also, when the main switch of the electric motor for driving a vehicle (electric vehicle) is turned off, the electric compressor 1 is immediately stopped, but the electric fan 3 is operated by the timer unit, similarly to the case where the air conditioner switch 9 is turned off. It is also possible to continue driving for a predetermined time T1 set at 80. Further, in the above-described embodiment, an example in which the present invention is applied to an air conditioner of a vehicle has been described. However, any refrigeration cycle device including the electric compressor 1 can be applied to other than a vehicle.

Further, the present invention can be applied to a heat pump system in which another evaporator is provided outside the room and the flow of the refrigerant is switched to obtain a heating function.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention.

FIG. 2 is a timing chart for explaining the operation of the embodiment.

FIG. 3 is a timing chart for explaining the operation of the conventional device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Electric compressor, 2 ... Condenser, 3 ... Electric fan, 8 ... Control device (control means) for air conditioning.

Claims (4)

[Claims] An electric compressor for compressing and discharging a refrigerant (1)
A condenser (2) for condensing refrigerant discharged from the electric compressor (1); and an electric fan (3) for sending cooling air to the condenser (2). A refrigeration cycle apparatus comprising a control means (8) for operating the electric fan (3) even after the stop of (1). 2. The control means (8) controls at least one of an operation time of the electric fan (3) and a blown air amount according to a physical quantity related to a high-pressure side pressure of a refrigeration cycle. The refrigeration cycle apparatus according to claim 1. 3. The control means (8) decreases at least one of an operation time of the electric fan (3) and a blown air amount with a decrease in outside air temperature. A refrigeration cycle apparatus as described in the above. 4. A refrigeration cycle apparatus mounted on a vehicle, wherein the control means (8) determines an operation time and an air flow rate of the electric fan (3) as the traveling speed of the vehicle increases. The refrigeration cycle apparatus according to any one of claims 1 to 3, wherein at least one of them is reduced.