JP4445246B2 - Air conditioner - Google Patents

Description

  The present invention relates to blown air temperature control of an air conditioner that performs objective air conditioning such as a computer room.

  A conventional air conditioner includes a compressor, a condenser, an expansion valve, and an evaporator whose capacity can be controlled. Each part is connected via a pipe to form a refrigeration cycle, and the capacity of the compressor is controlled. A control unit, and a temperature sensor for measuring the temperature of the blown air cooled by passing through the evaporator and sending the measured value to the control unit, the ambient temperature of the equipment to be cooled to which the cooled air is sent, and An ambient temperature sensor that measures ambient humidity and an ambient humidity sensor are provided, and the dew point temperature of the device to be cooled is calculated from the detected values of the temperature sensor and the humidity sensor, and the dew point temperature and the blown air temperature detected by the outlet temperature sensor If the air temperature is lower than the dew point temperature, there is a possibility that condensation will occur on the surface of the equipment to be cooled. Degree is raised, and is aimed to prevent condensation of the cooling target device (e.g., see Patent Document 1).

JP-A-9-236298

In the conventional air conditioner configured as described above, when the blown air temperature is lower than the dew point temperature, the evaporator temperature is increased by lowering the compressor capacity, thereby raising the blown air temperature. . At this time, since the compressor capacity is reduced, the cooling performance is lowered, the cooling capacity, which is the original purpose of the air conditioner, is lowered, and the room temperature is increased, so that the room temperature may become unstable.
Since it is important for an air conditioner such as a computer room to stabilize the room temperature, it is a big problem that the cooling performance is lowered to raise the temperature of the blown air.

  The present invention has been made in order to solve the above-described problems. A first object of the present invention is to perform a control in which the blown air temperature is lower than the dew point temperature of the cooling portion and the blown air temperature is increased. By controlling both the capacity and the indoor fan capacity, the air conditioner is provided which can prevent condensation while stabilizing the room temperature by increasing the blown air temperature while ensuring the cooling capacity. .

In the air conditioner according to the present invention, a capacity-controllable compressor, a condensing side heat exchanger, a flow rate control valve, and an evaporation side heat exchanger are connected to circulate a refrigerant, an outdoor fan, and capacity control A control unit that controls the capacity of the indoor blower that can be controlled, a capacity-controllable compressor and a capacity-controllable indoor fan, a suction temperature sensor that detects the suction air temperature of the air conditioner, and an evaporation side heat exchanger A temperature sensor for detecting the temperature of the blown air blown out, a dehumidifying operation signal receiving section for receiving a dehumidifying operation command signal from the outside provided in the control section, and detecting the temperature of the portion to be cooled in the computer room comprising a temperature sensor for computer room, and a humidity sensor for computer room for detecting the humidity of the cooling target portion of the computer room, control unit, temperature sensor and cooling pairs from the detection value of the computer room humidity sensor Calculating the dew-point temperature of the section, higher compressor capacity in accordance with the operation command signal dehumidification, during dehumidifying operation to control low indoor blower capacity, if the supply air temperature drops below the dew point temperature, the compressor capacity and the indoor blower capacity And controlling the blown air temperature to be equal to or higher than the dew point temperature while keeping the cooling capacity of the air conditioner calculated from the intake air temperature, blown air temperature, and indoor fan capacity constant.

  This invention calculates the dew point temperature of the part to be cooled in the computer room from the detection values of the temperature sensor and the humidity sensor, and controls the compressor capacity and the indoor fan capacity when the blown air temperature is lower than the dew point temperature. Control both the compressor capacity and the indoor fan capacity so that the air temperature is equal to or higher than the dew point temperature while keeping the cooling capacity of the air conditioner calculated from the air temperature, blown air temperature and indoor fan capacity constant. By doing so, by increasing the blown air temperature while ensuring the cooling capacity, it is possible to prevent condensation while stabilizing the room temperature.

Embodiment 1 FIG.
Hereinafter, the control method of the refrigerating cycle by Embodiment 1 of this invention is demonstrated. FIG. 1 shows an air conditioner according to Embodiment 1 of the present invention.
In FIG. 1, 1 is a compressor whose capacity can be controlled, 2 is a condensation side heat exchanger, 3 is a flow control valve, 4 is an evaporation side heat exchanger, and constitutes a refrigerant circuit connected in order by piping. . 9 is an outdoor blower, 6 is a capacity-controllable indoor blower, 7 is a blowout temperature sensor that detects the temperature of blown air blown through the evaporation side heat exchanger 4, and 12 is a suction air temperature of the air conditioner. A suction temperature sensor 8 is a control unit that controls the compressor 1 capable of capacity control and the indoor blower 6 capable of capacity control.

  Reference numeral 10 denotes a temperature sensor that is installed indoors and detects the temperature of the part to be cooled, and 11 is a humidity sensor that is installed indoors and detects the humidity of the part to be cooled.

The operation of the air conditioner configured as described above will be described.
During the cooling operation of the air conditioner, the control unit 8 calculates the dew point temperature of the cooling target part from the temperature and humidity detection values of the cooling target part by the temperature sensor 10 and the humidity sensor 11. When the dew point temperature is compared with the detection value of the blow-out temperature sensor 7, if the blow-out temperature is lower than the dew point temperature, there is a possibility that dew condensation will occur in the portion to be cooled.

  The relationship between the compressor capacity, the evaporation temperature, and the cooling performance is as shown in FIG. 2, and when the compressor capacity decreases, the evaporation temperature increases and the cooling capacity also decreases. On the other hand, the relationship between the indoor fan capacity (indoor air volume), the evaporation temperature, and the cooling capacity is as shown in FIG. 3, and as the indoor air volume increases, the evaporation temperature increases and the cooling capacity also increases. The cooling capacity can be calculated from the difference ΔT between the intake air temperature and the blown air temperature detected by the intake air temperature sensor and the indoor fan capacity (indoor air volume), which has a relationship as shown in FIG.

Therefore, the control unit 8 performs the following control so that the blown air temperature becomes equal to or higher than the dew point.
While lowering the compressor capacity and increasing the evaporation temperature of the evaporator to raise the blowing temperature, while looking at the difference ΔT between the intake air temperature and the blowing air temperature and the state of the cooling capacity calculated from the indoor fan capacity, The indoor fan capacity is increased and the cooling capacity is controlled so as not to decrease.

  With the above operation, the indoor air temperature can be kept constant while preventing condensation on the portion to be cooled.

Embodiment 2.
Hereinafter, the control method of the refrigerating cycle by Embodiment 2 of this invention is demonstrated. FIG. 5 shows an air conditioner according to Embodiment 2 of the present invention.
In FIG. 5, 1 is a compressor whose capacity can be controlled, 2 is a condensation side heat exchanger, 3 is a flow control valve, 4 is an evaporation side heat exchanger, and constitutes a refrigerant circuit connected by piping in order. . 9 is an outdoor blower, 6 is a capacity-controllable indoor blower, 7 is a blowout temperature sensor that detects the temperature of blown air blown through the evaporation side heat exchanger 4, and 12 is a suction air temperature of the air conditioner. Suction temperature sensor, 8 is a control unit that controls compressor 1 capable of capacity control and indoor blower 6 capable of capacity control, and 13 is a dehumidification operation signal that receives an external dehumidification operation command signal provided in control unit 8 It is a receiving part. An external dehumidifying operation command is given from, for example, a remote controller or an external switch.

  Reference numeral 10 denotes a temperature sensor that is installed indoors and detects the temperature of the part to be cooled, and 11 is a humidity sensor that is installed indoors and detects the humidity of the part to be cooled.

The operation of the air conditioner configured as described above will be described.
During the cooling operation of the air conditioner, the air conditioner that has received the dehumidification operation command signal by the dehumidification operation signal receiver 13 performs the dehumidification operation. In this dehumidifying operation control, it is efficient to lower the evaporation temperature of the evaporator 4 in order to increase the dehumidifying capacity. For this reason, control is performed so that the compressor capacity is increased and the indoor fan capacity is decreased.
However, when such a dehumidifying operation control is performed, the blown air temperature becomes low, and therefore there is a possibility that dew condensation will occur in the portion to be cooled depending on the indoor suction temperature and load conditions.

Therefore, the control unit 8 calculates the dew point temperature of the cooling target portion from the temperature and humidity detected values of the cooling target portion by the temperature sensor 10 and the humidity sensor 11, and compares the dew point temperature with the detection value of the blowing temperature sensor 7, When the blowing temperature is lower than the dew point temperature, the following control is performed so that the blowing air temperature becomes equal to or higher than the dew point.
The discharge temperature is raised by reducing the compressor capacity and setting the evaporation temperature of the evaporator high. However, in this case, the indoor fan capacity is increased in order to prevent the cooling capacity from being reduced due to the compressor capacity reduction.

  By the above operation, the control unit 8 controls to keep the cooling capacity constant by increasing the indoor fan capacity while increasing the blowing temperature, thereby preventing condensation on the portion to be cooled while performing the dehumidifying operation. The indoor air temperature can be kept constant.

1 is a system configuration diagram showing an air conditioner according to Embodiment 1 of the present invention. It is a characteristic view which shows the relationship between compressor capacity | capacitance, evaporation temperature, and cooling capacity. It is a characteristic view which shows the relationship between indoor fan capacity | capacitance (indoor air volume), evaporation temperature, and cooling capacity. It is a characteristic view which shows the relationship with the difference (DELTA) T of intake air temperature and blowing air temperature, indoor air volume, and cooling capacity. It is a system block diagram which shows the air conditioning apparatus by Embodiment 2 of this invention.

Explanation of symbols

1: Capacity controllable compressor
2: Condensation side heat exchanger (outdoor heat exchanger)
3: Flow control valve 4: Evaporation side heat exchanger (indoor heat exchanger)
6: Indoor blower with capacity control 7: Blowout temperature sensor
8: Control unit 9: Outdoor fan 10: Temperature sensor 11: Humidity sensor 12: Suction temperature sensor 13: Dehumidification operation signal receiving unit

Claims (2)

A capacity controllable compressor, a condensation side heat exchanger, a flow rate control valve, and an evaporation side heat exchanger, and a refrigeration cycle for circulating refrigerant;
An outdoor blower,
Capacity controllable indoor fan,
A controller that performs capacity control of the capacity-controllable compressor and capacity-controllable indoor fan;
An intake temperature sensor for detecting the intake air temperature of the air conditioner;
A blowout temperature sensor for detecting a blown air temperature blown through the evaporation side heat exchanger;
A dehumidifying operation signal receiving unit provided in the control unit for receiving a dehumidifying operation command signal from the outside;
A temperature sensor for detecting the temperature of the part to be cooled in the computer room;
A humidity sensor that detects the humidity of the cooling target portion of the computer room,
The controller calculates the dew point temperature of the cooling target portion of the computer room from the detected values of the temperature sensor and the humidity sensor, and controls the dehumidifying operation to increase the compressor capacity and lower the indoor fan capacity according to the dehumidifying operation command signal. When the blown air temperature falls below the dew point temperature, the compressor capacity and the indoor fan capacity are controlled, and the cooling capacity of the air conditioner calculated from the intake air temperature, blown air temperature, and indoor fan capacity is kept constant. The air conditioner is controlled so that the blown air temperature is equal to or higher than the dew point temperature while being maintained. Control unit, such that the blowing air temperature is equal to or higher than the dew point temperature, the compressor capacity is reduced, according to claim 1 Symbol placement of the air conditioner, characterized in that to increase the blower capacity.

Images