air conditioner

Abstract

To provide an air conditioner capable of suppressing noise at starting.SOLUTION: An air conditioner 10 includes a cycle which includes an evaporator (indoor heat exchanger 160), a compressor 230, a condenser (outdoor heat exchanger 280), a four-way valve 250, and an expansion valve 240. The air conditioner 10 further includes an evaporation temperature detecting unit 273, a condensation temperature detecting unit 275, a compression ratio calculating unit 213, a setting unit 214, and a control unit 215. The evaporation temperature detecting unit 273 detects an evaporation temperature of an evaporated refrigerant. The condensation temperature detecting unit 275 detects a condensation temperature of a condensed refrigerant. The compression ratio calculating unit 213 calculates a compression ratio calculated from the evaporation temperature and the condensation temperature. The setting unit 214 sets a minimum rotation speed of the compressor 230 on the basis of the compression ratio. The control unit 215 controls to change a target rotation speed of the compressor 230 to the minimum rotation speed.SELECTED DRAWING: Figure 5

Claims

1. An air conditioner comprising a cycle including an evaporator, a compressor, a condenser, a four-way valve, and an expansion valve, An evaporation temperature detection unit for detecting the evaporation temperature of the evaporating refrigerant, A condensation temperature detection unit that detects the condensation temperature of the condensing refrigerant, A compression ratio calculation unit that calculates the compression ratio from the aforementioned evaporation temperature and condensation temperature, A setting unit that sets the minimum rotational speed of the compressor based on the compression ratio, A control unit that controls the compressor to change its target rotational speed to the minimum rotational speed, A rotational speed calculation unit calculates the rotational speed of the compressor based on the set temperature set in the air conditioner and the room temperature. A comparison unit that compares the calculated rotational speed with the minimum rotational speed. Furthermore, The control unit, An air conditioner that operates the compressor at the minimum rotational speed when the minimum rotational speed is greater than the calculated rotational speed.

2. The evaporation temperature detection unit detects the evaporation temperature at the bottom of the compressor, The air conditioner according to claim 1, wherein the condensation temperature detection unit detects the condensation temperature at the bottom of the compressor.

3. An air conditioner comprising a cycle including an evaporator, a compressor, a condenser, a four-way valve, and an expansion valve, An evaporation temperature detection unit for detecting the evaporation temperature of the evaporating refrigerant, A condensation temperature detection unit that detects the condensation temperature of the condensing refrigerant, A compression ratio calculation unit that calculates the compression ratio from the aforementioned evaporation temperature and condensation temperature, A setting unit that sets the minimum rotational speed of the compressor based on the compression ratio, A control unit that controls the compressor to change its target rotational speed to the minimum rotational speed, A rotation speed detection unit for detecting the rotation speed of the compressor, A comparison unit that compares the detected rotation speed with the minimum rotation speed, Furthermore, The control unit, An air conditioner that operates the compressor at the minimum rotational speed when the minimum rotational speed is greater than the detected rotational speed.

4. An air conditioner comprising a cycle including an evaporator, a compressor, a condenser, a four-way valve, and an expansion valve, An evaporation temperature detection unit for detecting the evaporation temperature of the evaporating refrigerant, A condensation temperature detection unit that detects the condensation temperature of the condensing refrigerant, A compression ratio calculation unit that calculates the compression ratio from the aforementioned evaporation temperature and condensation temperature, A setting unit that sets the minimum rotational speed of the compressor based on the compression ratio, A control unit that controls the compressor to change its target rotational speed to the minimum rotational speed. Furthermore, The control unit controls the compressor to change the target rotational speed to the minimum rotational speed from the time the compressor transitions to a stopped state until it enters an started state and the start-up period has elapsed, in an air conditioner.

5. The air conditioner according to claim 4, wherein the control unit further controls the steady-state rotation speed of the compressor to change it to the minimum rotation speed after the rise-up period has elapsed and until the steady-state period has elapsed.

6. The air conditioner according to claim 4, wherein the control unit operates the compressor at a final rotational speed lower than the minimum rotational speed until the compressor transitions to a stopped state after the start-up period has elapsed.

7. The air conditioner according to claim 5, wherein the control unit operates the compressor at a final rotational speed lower than the minimum rotational speed until the compressor transitions to a stopped state after the steady period has elapsed.

8. The air conditioner according to claim 4, wherein the control unit sets the rate at which it changes the target rotation speed to the minimum rotation speed to a slower rate at which it changes outside of the rise-up period.

9. The air conditioner according to claim 5, wherein the control unit makes the change speed at which the steady-state rotation speed is changed to the minimum rotation speed slower than the normal change speed outside of the steady-state period.

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