JPH07234046A - Air conditioner - Google Patents

Abstract

PURPOSE:To protect a refrigerating cycle by a method wherein an input current of a compressor and the temperature of an indoor-side heat exchanger are detected, a gas escape in operation is judged to be present when detected values deviate from prescribed ranges, and the operation of the compressor is stopped at that time. CONSTITUTION:Information on the operating frequency of a compressor, the temperature of an indoor-side heat exchanger and an input current of the compressor is taken in a control system from detecting means 101, 104 and 107 provided therefor respectively. The information is compared by comparing means 103, 106 and 109 with prescribed values stored in a compressor operating frequency set value storage means 102, an indoor-side heat exchanger temperature set value storage means 105 and a compressor input current set value storage means 108 respectively, and the operating frequency of the compressor 113 is increased or decreased by a compressor operating frequency setting means 111 and a compressor operating frequency varying means 112. In this way, an operating frequency control is executed when values of the input current of the compressor and the temperature of the indoor-side heat exchanger deviate from certain ranges, and thereby the compressor is protected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner, and more particularly to a control system for protecting a compressor from the escape of refrigerant gas from a refrigeration cycle or from overload operation.

[0002]

2. Description of the Related Art Conventionally, in an air conditioner, in order to protect the compressor, an overload relay that reacts to temperature or input current is added to the compressor surface, and the surface temperature of the compressor or the input current exceeds a certain value. In this case, the compressor was stopped.

The conventional air conditioner will be described below with reference to the drawings. FIG. 4 is a refrigeration cycle diagram in a conventional heat pump type air conditioner.

As shown in the figure, 1 is a compressor, 2
Is a four-way valve, 3 is a condenser (outdoor heat exchanger), 4 is an outdoor fan, 5 is a capillary tube, 6 is an evaporator (indoor heat exchanger), 7 is an indoor fan, 8 is an accumulator, Reference numeral 9 is an overload relay device of the compressor.

[0005]

However, the air conditioner configured as described above has the following problems.

That is, when the air conditioner is operated under a high load condition or when the refrigeration cycle is operated with the refrigerant removed, the discharge temperature and the temperature of the motor coil in the compressor generally increase. In the conventional apparatus, the temperature is detected only on the surface of the compressor, so that it may not be possible to protect the compressor from burnout depending on the conditions. Further, the input current value may decrease when the refrigerant gas escapes. For this reason, the conventional protection means can only support protection under some operating conditions. The present invention has been made to solve the above problems, and an object of the present invention is to simultaneously monitor the compressor input current and the indoor heat exchanger temperature and protect the compressor in any operating condition.

[0007]

In order to solve the above problems, the air conditioner of the present invention has the means shown in FIG. 1 and the values of the compressor input current and the indoor heat exchanger temperature deviate from a certain range. In this case, the upper limit of the operating frequency of the compressor is regulated, or the operation is stopped, and the control contents are displayed on the indoor unit to inform the user of the air conditioner.

[0008]

The present invention has the following actions due to the above means. That is, by constantly monitoring the compressor input current and the indoor heat exchanger temperature, when the values of the compressor input current and the indoor heat exchanger temperature deviate from a certain range, operating frequency control is performed to protect the compressor. You can

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a refrigeration cycle of an air conditioner according to an embodiment of the present invention. As shown in the figure, 1 is a compressor, 2 is a four-way valve, 3 is a condenser (outdoor heat exchanger), 4 is an outdoor fan, 5 is a capillary tube,
6 is an evaporator (indoor heat exchanger), 7 is an indoor fan, 8
Is an accumulator, 9 is an indoor heat exchanger temperature sensor, and 10 is a compressor input current sensor.

In this refrigeration cycle, during the cooling operation, the refrigerant discharged from the compressor 1 flows through the four-way valve 2, the condenser 3, the capillary tube 5, the evaporator 6 and the accumulator 8 and is sucked into the compressor 1.

Next, the operation of the control circuit according to the present invention will be described with reference to FIG.

In FIG. 1, the information taken into the control system is the compressor operating frequency, the indoor heat exchanger temperature, and the compressor input current.

These pieces of information are taken into the control system from the compressor operating frequency detecting means (step 101), the indoor heat exchanger temperature detecting means (step 104) and the compressor input current detecting means (step 107), respectively. Compressor operating frequency set value storage means (step 102), indoor heat exchanger temperature set value storage means (105), compressor input current set value storage means (step 108), and comparison means (steps 103, 106, 109). Is compared with the specified value by the compressor operating frequency setting means (step 111),
Compressor operating frequency changing means (step 112)
The operating frequency of the compressor (step 113) is increased or decreased by.

FIG. 3 is a flow chart of this control flow. First, the compressor frequency f, the indoor heat exchanger temperature Ti, and the compressor input current I are detected (steps 201 to 203). Subsequently, it is determined whether the operation is the cooling operation or the heating operation (step 204). In the case of the cooling operation,
It is determined whether or not the value of f is the specified value fc (step 205),
It is determined whether the I value is below Ia (step 2
06). Further, it is determined whether or not the Ti value is lower than Tic (step 207).

As a result of the judgment, when the heating operation is performed (step 204), it is judged whether the value of f is the specified value fh (step 208), and it is judged whether the I value is less than Ia (step). 209). Further, it is determined whether the Ti value is lower than Tih (step 210). If each condition is not satisfied, the process returns to step 201, and if satisfied, the operation of the compressor is immediately stopped (step 207), and at the same time, the control contents are displayed on the indoor unit (step 212). By this control, it is possible to avoid a refrigeration cycle failure due to outgassing.
In addition, although the above-mentioned embodiment explained the separate type air conditioner, the same effect can be expected in the integrated type air conditioner.

[0017]

As described above, the present invention provides the input current of the compressor of the heat pump type air conditioner,
When the temperature of the indoor heat exchanger is detected, and this value deviates from a certain range, it is judged that the gas is out of operation and the operation of the compressor is stopped to protect the refrigeration cycle.

[Brief description of drawings]

FIG. 1 is a control block diagram of an air conditioner according to an embodiment of the present invention.

FIG. 2 is a refrigeration cycle diagram of the air conditioner.

FIG. 3 is a control flowchart of the air conditioner.

FIG. 4 is a refrigeration cycle diagram of a conventional air conditioner.

[Explanation of symbols]

 1 Compressor 2 4-way valve 3 Condenser 4 Outdoor fan 5 Capillary tube 6 Evaporator 7 Indoor fan 8 Accumulator 9 Compressor overload relay

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Claims (2)

[Claims] 1. A compressor input current detecting means for detecting and outputting a compressor input current, a comparing means for comparing the output of the compressor input current detecting means with a preset current and outputting a control signal, and An air conditioner provided with a compressor operating frequency setting means for receiving and setting the compressor operating frequency, a compressor operating frequency varying device for varying the compressor operating frequency, and a display means for receiving the control signal and displaying the control content on the indoor unit. Machine. 2. A compressor input current detecting means for detecting and outputting a compressor input current, and a first comparing means for comparing the output of the compressor input current detecting means with a preset current and outputting a control signal. The indoor heat exchanger temperature detecting means for detecting and outputting the indoor heat exchanger temperature, and the second for outputting the control signal by comparing the output of the indoor heat exchanger temperature detecting means with a preset temperature. Control means for receiving the signal and lowering the current for a certain period of time and lowering the operating frequency of the compressor when the indoor heat exchanger temperature is higher than the constant temperature during the cooling operation and lower than the constant temperature during the heating operation. And a compressor operating frequency setting means for receiving the control signal and setting the compressor operating frequency. And compressor operation frequency varying device for varying the Ssa operation frequency, an air conditioner provided with a display means for displaying the control content to the indoor unit receives the control signal.