JPH1096545A - Air conditioner and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to converge room temperature or diffused air temperature to a setting value smoothly by controlling the capacity of a compressor responding with a differential value between a detected temperature and a setting value of a temperature detection means which detects room temperature and diffused air temperature and controlling the air volume of an indoor fan to a value in uniformity with the capacity of a compressor. SOLUTION: The frequency of a compressor (which is the output frequency of an inverter device 11) or the capacity of a compressor 1 is controlled in uniformity with a differential value (air conditioning load) between a detected temperature and a room temperature setting value of a suction air sensor 15 in a control device 20 while driving an air conditioner. More specifically, in the case when the detected value is higher than the room temperature setting value, the compression frequency is enhanced in uniformity with the differential temperature, thereby increasing the capacity. The frequency of the compressor (the output frequency of an inverter 14) or the air volume of an indoor fan 13 is controlled to a value which complies with the frequency of the compressor. This construction makes it possible to provide an optimum air conditioning performance which responds with room temperature, thereby converging the room temperature to the setting value smoothly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner for controlling the capacity of a compressor and controlling the air volume of an indoor blower.

[0002]

2. Description of the Related Art Generally, in an air conditioner, the operation of the capacity of a compressor and the operation of the air volume of an indoor blower are performed independently of each other. The operation of the capacity of the compressor is performed in order to control the room temperature (for example, the intake air temperature) to be substantially equal to the set value. The air volume operation of the indoor blower is used, for example, for reducing the amount of air blown out in the dehumidifying operation.

Some air conditioners installed in a computer room or a communication room control the room temperature, the blown air temperature, and the blown air humidity by controlling the capacity of a compressor and the air volume of a blower. For example, there is one disclosed in Japanese Patent Application No. 62-287560.

[0004]

[Problems to be solved by the invention]

(1) When it is necessary to control the indoor temperature or the blow-out air temperature and not particularly to control the blow-out air humidity, the capacity of the compressor is operated according to the room temperature or the blow-out air temperature, and the indoor blower has a constant air volume. Driven by

[0005] In this case, the air volume of the indoor blower is set to be relatively large from the viewpoint of securing a sufficient air volume to be blown into the room and because the humidity is not particularly considered. However, when the air volume of the indoor blower is large, the power consumption of the indoor blower increases, which leads to an increase in operating costs.

(2) When it is necessary to control both the indoor temperature and the blown air temperature, the capacity of the compressor is operated according to the indoor temperature, and the air volume of the indoor blower is operated according to the blown air temperature. Sometimes. Alternatively, the air volume of the indoor blower may be operated according to the indoor temperature, and the capacity of the compressor may be operated according to the blown air temperature.

However, as in the latter case, in a situation where the air volume of the indoor blower is operated according to the indoor temperature and the capacity of the compressor is operated according to the temperature of the blown air, the air volume of the indoor blower becomes the maximum value or the minimum value. Will be fixed to either.

[0008] When the air volume of the indoor blower is fixed to the maximum value, the power consumption of the indoor blower increases, which leads to an increase in operating costs. When the air volume of the indoor blower is fixed to the minimum value, there are problems such as an insufficient air volume blown into the room and an excessive amount of dehumidification.

The present invention has been made in view of the above circumstances, and the air conditioners of the first and second inventions can obtain an optimum air conditioning capacity according to the indoor temperature or the blown air temperature, and The temperature or the outlet air temperature can be smoothly converged to the set value, and the optimum and necessary and sufficient amount of outlet air that matches the air-conditioning capacity can be obtained, thus reducing unnecessary power consumption and excess dehumidification. It is another object of the present invention to stabilize the refrigerating cycle by avoiding the fluctuation and reducing the fluctuation of the evaporator pressure.

According to the control method of the air conditioner of the third invention, it is possible to obtain an optimum air conditioning capacity according to the room temperature or the blown air temperature, and to smoothly converge the room temperature or the blown air temperature to the set value. In addition, it is possible to obtain an optimal and necessary and sufficient amount of blown air corresponding to the air conditioning capacity, avoid unnecessary increase in power consumption and excess dehumidification, and reduce fluctuations in evaporator pressure. And stabilize the refrigeration cycle.

[0011]

According to a first aspect of the present invention, there is provided an air conditioner comprising: a refrigeration cycle in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are connected by piping; and a room for the outdoor heat exchanger. An outer blower, and an indoor blower for the indoor heat exchanger,
Temperature detecting means for detecting the indoor temperature or the temperature of the blown air; first control means for operating the capacity of the compressor in accordance with a difference between the detected temperature of the temperature detecting means and a set value; Second control means for setting a value according to the capacity of the compressor.

An air conditioner according to a second aspect of the present invention provides a refrigeration cycle in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are connected by piping, an outdoor blower for the outdoor heat exchanger, and an indoor fan. An indoor-side blower for a heat exchanger, a first inverter for outputting a drive voltage for the compressor, a second inverter for outputting a drive voltage for the indoor blower, and a temperature detector for detecting an indoor temperature or an outlet air temperature Means, first control means for controlling the output frequency of the first inverter device according to the difference between the temperature detected by the temperature detection means and the set value, and the output frequency of the second inverter device to the first inverter device. And a second control means for setting the output frequency to a value corresponding to the output frequency.

According to a third aspect of the present invention, there is provided an air conditioner control method comprising: a refrigeration cycle in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are connected by piping; an outdoor blower for the outdoor heat exchanger; An air conditioner equipped with an indoor-side blower for an indoor heat exchanger and capable of controlling the capacity of the compressor and the air volume of the indoor blower respectively detects an indoor temperature or an outlet air temperature, and detects a difference between the detected temperature and a set value. , The capacity of the compressor is operated, and the air volume of the indoor blower is set to a value corresponding to the capacity of the compressor.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a compressor 1, an oil separator 2, an outdoor heat exchanger 3, a liquid receiver 4, an electric expansion valve 5, an indoor heat exchanger 6, and an accumulator 7 are connected by piping, and a refrigeration cycle is performed. Be composed.

The compressor 1 performs a variable capacity operation in accordance with the frequency of the drive voltage supplied from the inverter device 11, and discharges a high-temperature and high-pressure gas refrigerant in the direction of the arrow. This gas refrigerant is guided to the outdoor heat exchanger (condenser) 3 and exchanges heat with the outside air to be condensed to become a high-pressure liquid refrigerant. The liquid refrigerant is guided to the expansion valve 5, where it is decompressed and becomes a low-pressure liquid-gas mixed refrigerant. Further, the liquid-gas mixed refrigerant is supplied to the indoor heat exchanger (evaporator) 6.
And evaporates by exchanging heat with the indoor air to become low-pressure gas, which is sucked into the compressor 1 again. Thereafter, by repeating the same cycle, the room can be cooled and the heat taken from the room can be released to the outside air through the condenser.

An outdoor blower 12 for supplying outdoor air is provided for the outdoor heat exchanger 3. An indoor blower 13 for supplying indoor air is provided for the indoor heat exchanger 6.
The indoor blower 13 performs an air volume variable operation according to the frequency of the drive voltage supplied from the inverter device 14.

An intake air temperature sensor 15 is provided in the air passage of the indoor air sucked by the indoor blower 13.
The temperature detected by the intake air temperature sensor 15 is taken as the room temperature in the room to be air-conditioned.

An outlet air temperature sensor 16 is provided in an air passage of the outlet air blown into the room through the indoor heat exchanger 6. A superheat sensor 17 is provided in a pipe extending from the accumulator 7 to the refrigerant suction port of the compressor 1 as superheat detection means.
Is provided. The superheat degree sensor 17 detects the degree of superheat of the refrigerant in the refrigeration cycle, that is, the degree of superheat of the refrigerant in the indoor heat exchanger 6 functioning as an evaporator.

The main function of the control device 20 is to control the compressor frequency (= air-conditioning load) according to the difference between the temperature detected by the intake air temperature sensor 15 and a preset indoor temperature set value (= air-conditioning load).
The first control means for controlling the capacity of the compressor 1, ie, the output frequency of the inverter device 11, and the blower frequency (= the output frequency of the inverter device 14), ie, the air volume of the indoor blower 13, are set to values corresponding to the compressor frequency. And second control means.

Next, the operation of the above configuration will be described with reference to the flowchart of FIG. 2 and the blower frequency setting condition of FIG. The blower frequency setting condition in FIG.
0 is stored in advance in the memory 0.

The indoor temperature is detected by the intake air temperature sensor 15, and the detected temperature is compared with a predetermined indoor temperature set value. If the detected temperature is higher than the room temperature set value, the compressor frequency is increased according to the temperature difference, and the capacity is increased. If the detected temperature is equal to or lower than the room temperature set value, the compressor frequency is reduced according to the temperature difference.

When the compressor frequency is high, the amount of circulating refrigerant increases, and the pressure of the refrigerant in the indoor heat exchanger 6 as an evaporator (hereinafter, referred to as evaporator pressure) decreases, and the cooling capacity increases. When the compressor frequency is low, the amount of circulating refrigerant decreases, the evaporator pressure increases, and the cooling capacity decreases.

By operating the compressor frequency in this manner, the optimum air-conditioning capacity (= cooling capacity) according to the room temperature.
Can be obtained, whereby the room temperature can be smoothly converged to the set value.

On the other hand, when the compressor frequency is operated, the value of the blower frequency corresponding to the compressor frequency is read from the blower frequency setting condition of FIG. 3, and the blower frequency is operated so as to become the value.

That is, when the compressor frequency is set high, the blower frequency is also set high and the indoor blower 13
Is increased. When the compressor frequency is set low, the blower frequency is also set low, and the air volume of the indoor blower 13 is reduced.

Taking the case where the variable range of the compressor frequency is 30 Hz to 90 Hz and the variable range of the operating frequency of the indoor blower 13 is 30 Hz to 60 Hz as an example, when the compressor frequency is 90 Hz, the blower frequency is
When the compressor frequency is 60 Hz, the compressor frequency is 60 Hz, the blower frequency is 45 Hz, and when the compressor frequency is 30 Hz, the blower frequency is 30 Hz.

In the case of the evaporator, when the blower air volume increases, the heat transfer coefficient between the refrigerant and the room air increases, the evaporator pressure increases, and the cooling capacity increases. When the blower air volume decreases, the heat transfer coefficient between the refrigerant and the indoor air decreases, the evaporator pressure decreases, and the cooling capacity decreases.

In order to increase the cooling capacity, the compressor frequency is increased to increase the capacity of the compressor 1, or the blower frequency is increased to increase the air volume of the indoor blower 13. When the compressor frequency is increased, the evaporator pressure is decreased, and when the blower frequency is increased, the evaporator pressure is increased.

Therefore, when increasing the cooling capacity, it is possible to suppress the fluctuation of the evaporator pressure while increasing the cooling capacity by increasing both the compressor frequency and the blower frequency. Can be stabilized.

Further, since the air volume of the indoor blower 13 follows a change in the cooling capacity, it is possible to obtain an optimum and necessary and sufficient blow-off air quantity corresponding to the cooling capacity, and to increase the unnecessary power consumption and the dehumidification amount as in the conventional case. And the like can be avoided as much as possible.

In the above embodiment, the capacity of the compressor 1 is operated in accordance with the difference between the detected temperature of the intake air temperature sensor 15 and the set value of the room temperature. The present invention can be similarly applied to a case where the capacity of the compressor 1 is operated according to the difference from the set value.

In the above embodiment, only the cooling operation has been described. However, the present invention can be similarly applied to a heat pump refrigeration cycle capable of performing a heating operation. In the above embodiment, the application to the air-cooled package air conditioner has been described. However, the present invention can be similarly applied to a water-cooled package air conditioner that cools a condenser with water.

[0033]

As described above, according to the present invention, the air conditioners of the first and second inventions detect the indoor temperature or the blown air temperature and respond to the difference between the detected temperature and the set value. The capacity of the compressor is manipulated and the air volume of the indoor blower is set to a value corresponding to the capacity of the compressor, so that an optimal air conditioning capacity according to the indoor temperature or the blown air temperature can be obtained. In addition, it is possible to smoothly converge the room temperature or the blown air temperature to the set value, and to obtain the optimum and necessary and sufficient blown air amount corresponding to the air conditioning capacity, thereby increasing unnecessary power consumption and excessive dehumidifying amount. And the like can be avoided, and the fluctuation of the evaporator pressure can be reduced to stabilize the refrigeration cycle.

According to a third aspect of the present invention, there is provided a method for controlling an air conditioner, comprising detecting a room temperature or an outlet air temperature, operating a capacity of the compressor in accordance with a difference between the detected temperature and a set value, and Since the air volume of the indoor blower is set to a value according to the capacity, it is possible to obtain the optimal air-conditioning capacity according to the indoor temperature or blown air temperature, and to smoothly set the indoor temperature or blown air temperature to the set value. It is possible to obtain an optimal and necessary and sufficient amount of blown air that matches the air-conditioning capacity, avoid unnecessary increase in power consumption and excessive dehumidification amount, and reduce fluctuations in evaporator pressure. The refrigeration cycle can be stabilized with less.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a refrigeration cycle and a control block according to one embodiment.

FIG. 2 is a flowchart for explaining the operation of the embodiment.

FIG. 3 is a view showing a blower air volume setting condition of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Compressor 3 ... Outdoor heat exchanger 5 ... Electric expansion valve 6 ... Indoor heat exchanger 11 ... Inverter apparatus 12 ... Outdoor blower 13 ... Indoor blower 14 ... Inverter apparatus 15 ... Suction air temperature sensor 16 ... Outlet air Temperature sensor 20 ... Control device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shigenori Waratani 1-4-3, Roppongi, Minato-ku, Tokyo Inside NTT Facilities Co., Ltd. (72) Inventor Kazuo Chiba 1-4-4 Roppongi, Minato-ku, Tokyo No. 33 Inside NTT Facilities

Claims (3)

[Claims] 1. A refrigeration cycle in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are connected by piping; an outdoor blower for the outdoor heat exchanger; and an indoor blower for the indoor heat exchanger. Temperature detecting means for detecting the indoor temperature or the temperature of the blown air; first control means for operating the capacity of the compressor according to a difference between the detected temperature of the temperature detecting means and a set value; And a second control means for setting a value according to the capacity of the compressor. 2. A refrigeration cycle in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are connected by pipes; an outdoor blower for the outdoor heat exchanger; and an indoor blower for the indoor heat exchanger. A first inverter that outputs a drive voltage to the compressor; a second inverter that outputs a drive voltage to the indoor blower; a temperature detector that detects an indoor temperature or a blown air temperature; First control means for operating the output frequency of the first inverter device according to the difference between the detected temperature and the set value; and changing the output frequency of the second inverter device to a value corresponding to the output frequency of the first inverter device. An air conditioner comprising: second control means for setting. 3. A refrigeration cycle in which a compressor, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger are connected by pipes, an outdoor blower for an outdoor heat exchanger, and an indoor blower for an indoor heat exchanger. In an air conditioner capable of controlling the capacity of the compressor and the air volume of the indoor blower, respectively, detecting the indoor temperature or the blown air temperature, and operating the capacity of the compressor according to a difference between the detected temperature and a set value; A method for controlling an air conditioner, comprising setting an air volume of an indoor blower to a value corresponding to a capacity of the compressor.