JP2001141285A - Control device for air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase a pressure of a refrigerant rushing in a four-way valve at the time of starting of operation to a value higher than a specified value since, when, during operation of a compressor, a pressure of a refrigerant rushing in the four-way valve is low, a circuit in the four-way circuit is not reliably switched, and to make it possible that the operation frequency of the compressor reaches a frequency satisfying the demand of an indoor machine early. SOLUTION: By providing a high low pressure difference of a refrigerant circuit by effecting operation at a compressor operation frequency satisfying the demand of an indoor machine 8 after a compressor 2 is operated at a frequency during starting for a specified time, a four-way valve 4 at the of operation is reliably switched.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an air conditioner equipped with an inverter-driven compressor and capable of cooling and heating by switching a four-way valve.

[0002]

2. Description of the Related Art Conventionally, a method of controlling this type of air conditioner is disclosed in Japanese Utility Model Laid-Open Publication No. Sho 63-194261, in which a high-low pressure difference in a refrigeration cycle at the start of a heating operation is reduced. , The compressor is operated for a predetermined time to switch the four-way valve.

[0003]

In such a conventional method of controlling an air conditioner, since the four-way valve forms a cooling circulation path for a while after the start of the heating operation, the indoor unit is heated by the hot air. Can not be blown out and the comfort is impaired.
In addition, when the pressure of the refrigerant entering the four-way valve during operation of the compressor is low, the circuit in the four-way valve may not be able to be reliably switched, and improvement is required.

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide an air conditioner control device capable of reliably switching a four-way valve at the start of operation.

[0005]

Means for Solving the Problems One means of the control device of the air conditioner of the present invention for solving the above-mentioned problem is that the outdoor control device determines in advance the compressor operating frequency required by the indoor unit at the start of operation. If the stored start-up frequency is lower than the start-up frequency, the compressor is operated at the start-up frequency for a certain period of time, and then the compressor is operated at the compressor operating frequency according to the request of the indoor unit, thereby generating a high-low pressure difference in the refrigerant circuit. Things.

Thus, a control device for an air conditioner that reliably switches the four-way valve is obtained.

Another means is that when the outdoor control device is operating the compressor at a start-up frequency stored beforehand at the start of operation, the outdoor controller responds to the request of the indoor unit when the discharge temperature reaches a predetermined discharge temperature. The compressor is operated at the compressor operating frequency.

Thus, a control device for an air conditioner having a short operation time at the starting frequency can be obtained.

Another means is that when the compressor operating frequency at the start of operation is lower than the start-up frequency stored in advance, the frequency increasing speed until reaching the start-up frequency is increased.

[0010] Thus, an air conditioner control device that shortens the time required to reach the compressor operating frequency in accordance with the demands of the indoor unit can be obtained.

Another means is that the outdoor control device switches ON / OFF signals of the four-way valve only at the start of operation,
When there is no change in the output of the ON / OFF signal of the four-way valve at the start of the operation, the operation is performed from the start of the operation at the compressor operation frequency according to the request of the indoor unit.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to an inverter-driven compressor, a four-way valve, an outdoor heat exchanger,
An electric expansion valve and an indoor unit are connected to form a heat pump type refrigerant circuit, and the compressor is driven and the four-way valve is driven based on inputs such as an operating frequency of the compressor required from the indoor unit and a discharge temperature. In the air conditioner provided with an outdoor control device that performs switching and control of an electric expansion valve, the outdoor control device determines the operating frequency of the compressor required from the indoor unit at the start of operation from a start-up frequency stored in advance. If low, after operating the compressor at the start-up frequency for a certain period of time, by operating at an operating frequency according to the request of the indoor unit to generate a high and low pressure difference of the refrigerant circuit, the four-way valve Has the effect of reliably performing the switching.

According to a second aspect of the present invention, when the outdoor control device is operating the compressor at the start-up frequency stored in advance at the start of the operation, the request of the indoor unit when the discharge temperature reaches the predetermined discharge temperature is obtained. By operating the compressor at the compressor operating frequency corresponding to the above, the operation time at the starting frequency is shortened.

According to a third aspect of the present invention, when the compressor operation frequency at the start of operation is lower than the start frequency, the outdoor control device increases the frequency rising speed until the compressor reaches the start frequency stored in advance. This has the effect of shortening the time required to reach the compressor operating frequency according to the requirements of the indoor unit.

According to a fourth aspect of the present invention, the outdoor control device switches the ON / OFF signal of the four-way valve only at the start of the operation, and when the output of the ON / OFF signal of the four-way valve does not change at the start of the operation. Has the effect that the compressor can be operated at the compressor operating frequency according to the request of the indoor unit from the start of operation.

Next, a specific example of the present invention will be described.

(Embodiment 1) FIG. 1 is a block diagram showing a configuration of an air conditioner of the present embodiment. An outdoor unit 1 has an inverter-driven compressor 2, an outdoor heat exchanger 3, a four-way valve 4, an electric expansion. The indoor unit 8 includes a valve 5, a discharge temperature sensor 6, an outdoor controller 7 including a microcomputer and its peripheral circuits.
And a refrigerant pipe 9 form a refrigerant circuit.

FIG. 2 is a chart showing a control state at the time of starting.

Hereinafter, a control state at the time of startup of the first embodiment of the present invention will be described with reference to the chart of FIG.

First, the outdoor control device 7 which has received the operation command from the indoor unit 8 starts the process 11 at the time of heating activation. Then, it is determined in step 12 whether the operation is the heating operation. If the operation is the heating operation, it is determined in step 13 whether the four-way valve ON signal is already output. If the four-way valve ON signal is already output, the normal operation is performed in step 24. Transfer to control.

If it is determined in step 13 that the four-way valve signal has not been output, a four-way valve ON signal is output, and the process proceeds to step 17. If it is determined in step 12 that the heating operation is not being performed, it is determined in step 14 whether the four-way valve ON signal has already been output. If the four-way valve ON signal has not been output, control is transferred to normal operation in step 24.

If it is determined in step 14 that the four-way valve signal has already been output, the four-way valve ON signal is turned off, and the routine proceeds to step 17.

Next, if the operation frequency determined by the operation command from the indoor unit 8 in step 17 is lower than the start-up frequency stored in the outdoor control device 7 in advance, the frequency increase speed is increased in step 18. And step 1
In step 9, the operation frequency is set to the startup frequency. Subsequently, in step 20, the compressor is turned on, and in step 21, the start timer is started. Thereafter, in step 23, the compressor is operated at the startup frequency until the startup timer expires.

Further, the discharge temperature in the refrigerant circuit is monitored by the discharge temperature sensor 6 until the start-up timer expires, and if the temperature exceeds the start-up control release temperature in step 22, the operation shifts to normal operation in step 24. You can control it.

[0025]

As described above, according to the present invention, the switching of the four-way valve ON / OFF signal is performed only at the start-up time by controlling the steps 12, 13, 13, and 15, so that the operation at the start of the operation can be performed. If the operation mode is the same as the previous operation, there is an advantageous effect that the control at the time of starting is not performed and the control can be immediately shifted to the normal operation control.

Further, by controlling the steps 19 and 22, the compressor operating time at the starting frequency can be shortened, thereby obtaining an advantageous effect of preventing the loss of indoor comfort.

Further, by controlling the steps 19 and 23, it is possible to obtain an advantageous effect that the refrigerant circuit can be reliably switched by setting the pressure of the refrigerant entering the four-way valve 4 to a predetermined value or more.

[Brief description of the drawings]

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

FIG. 2 is a chart showing a control state when the control device of the air conditioner is activated.

[Explanation of symbols]

 2 Inverter driven compressor 3 Outdoor heat exchanger 4 Four-way valve 5 Electric expansion valve 6 Discharge temperature sensor 7 Outdoor control device 8 Indoor unit 9 Refrigerant piping

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shigeho Yoshida 6-2-61 Imafukunishi, Joto-ku, Osaka-shi, Osaka Inside Matsushita Seiko Co., Ltd. (72) Kazuyuki Kobayashi 6-chome, Imafukunishi, Joto-ku, Osaka-shi, Osaka No.2 No.61 Matsushita Seiko Co., Ltd. F term (reference) 3L060 AA05 CC08 DD02 EE04

Claims (4)

[Claims] An inverter-driven compressor, a four-way valve, an outdoor heat exchanger, an electric expansion valve, and an indoor unit are connected to form a heat pump type refrigerant circuit, and the operating frequency of the compressor required by the indoor unit is controlled. In an air conditioner including an outdoor control device that drives the compressor, switches the four-way valve, and controls an electric expansion valve based on an input such as a discharge temperature, the outdoor control device is configured to perform indoor control at the start of operation. If the operating frequency of the compressor requested by the compressor is lower than the start-up frequency stored in advance, after operating the compressor at the start-up frequency for a certain period of time, the compressor is operated at the operating frequency according to the request of the indoor unit. A control device for an air conditioner, wherein the four-way valve is reliably switched by causing a difference in pressure between the refrigerant circuit and the pressure. 2. A compressor operating frequency according to a request of an indoor unit when the discharge temperature reaches a predetermined discharge temperature when the outdoor control device is operating the compressor at a start frequency stored in advance at the start of operation. The control device for an air conditioner according to claim 1, wherein the operation is performed by using. 3. When the outdoor control device has a compressor operating frequency at the start of operation that is lower than the start-up frequency, the outdoor control device increases the frequency rising speed until the start-up frequency reaches a pre-stored start-up frequency, thereby meeting the demands of the indoor unit. The control device for an air conditioner according to claim 1, wherein a time required to reach the corresponding compressor operation frequency is shortened. 4. The outdoor control device switches ON / OFF signals of the four-way valve only at the start of operation, and when there is no change in the output of the ON / OFF signal of the four-way valve at the start of operation, the outdoor control unit starts operation of the indoor unit. The control device for an air conditioner according to claim 1, wherein the operation is performed at a compressor operating frequency according to the request of (1).