JPS6313105B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to prevention of cold air by preventing indoor fans from simultaneously starting and blowing out cold air when heating operation of a heat pump type air conditioner is started.

The prevention of cold air at the start of heating operation of a conventional air conditioner will be explained with reference to FIG. 1 is a compressor, 2 is a four-way valve, 3 is an outdoor heat exchanger, 4 is a capillary tube, 5 is an indoor heat exchanger, and the arrows indicate the flow of refrigerant during heat pump operation (heating). 6 is an indoor fan, and 7 is an outdoor fan. In conventional air conditioners, a reliable and inexpensive pressure-sensitive element that operates using refrigerant pressure has not been developed.
Attach a bimetal thermostat etc. to the pipe at point A,
The operation of the indoor fan was stopped until the temperature of the section rose to the set temperature, and the indoor fan was operated only after the temperature of the indoor heat exchanger rose. This bimetal thermostat is sometimes attached at point B or between points A and B. The disadvantage of this method is firstly that the bimetallic thermometer is expensive. Second, the bimetal thermostat has poor temperature followability, and for example, when the defrosting operation starts, the fan should be stopped as soon as possible, but since the fan operation continues, the air conditioning operation is turned on during that time. It is.
Thirdly, when the air temperature or room temperature is low, the heat pump operation is started, the temperature of the indoor heat exchanger rises, and when the fan starts operating, the temperature of the heat exchanger suddenly drops, and then the temperature of the heat exchanger rises again. This causes the fan to stop. In this case, the indoor fan will not work for more than 30 minutes.
It may repeat ON and OFF, making it impossible to continue heating operation.

On the other hand, recently, microcomputers have been incorporated into air conditioners, which allow them to control the fan relatively freely, so they can stop the indoor fan for a certain period of time, such as 60 seconds or 90 seconds after heating starts, to prevent cold air from blowing out. be.

However, according to this method, the refrigeration cycle conditions are ignored and control is performed over a fixed period of time. If the refrigeration cycle is restarted after a certain period of time, the high pressure side of the refrigeration cycle will still be in a high temperature state, so the rate of increase in discharge pressure will be fast, and the discharge pressure of the compressor will become too high within the fan stop setting time, causing the compressor to lock. There is.

The present invention improves these drawbacks. In principle, the present invention uses a microcomputer, etc.
Incorporated into electronically controlled air conditioners,
It should be finished inexpensively. Since a microcomputer or the like is used, a description of the actual operating mechanism will be omitted. FIG. 2 is an explanatory diagram of the operation of an indoor fan, which is an embodiment of the air conditioner of the present invention for preventing cold air. First, the stop time is the stop time of the air conditioner counted from the time when the heating operation was stopped last time. According to the example, this time is preferably set to about one hour, but it depends on whether the compressor is a rotary type or a reciprocating type, the size of the refrigeration cycle, etc.
The setting time should be adjusted. In addition, the indoor fan operation switching room temperature at startup was set at approximately 12 degrees Celsius.
This takes into account changes in the sensible temperature due to the way clothes are worn in winter, but this temperature should be changed as appropriate depending on the size of the room and the purpose of use.

First, if the operation is stopped for less than one hour, the temperature on the high-pressure side of the refrigeration cycle is high, and the temperature of the compressor (especially rotary compressors) remains high without being cooled, so the temperature inside the chamber is high. Since the refrigerant does not condense and the temperature rises quickly, the fan speed is operated at the lowest speed for a certain period of time immediately after the start of operation, and then the fan speed is switched to a preset speed.

On the other hand, if the stop time has passed for more than 1 hour, the room temperature is divided into approximately 12°C or above and below.If the room temperature is above 12°C, the perceived temperature will not drop that much even if the fan is operated at low speed from the beginning. Carry out the same operation as in the case of less than 1 hour. On the other hand, if the temperature is below 12℃, if you start the indoor fan from the beginning, the temperature will drop even at low speeds and you will feel cold, so do not operate the fan for the first 90 seconds, then operate it at low speed for about 60 seconds, and then Control the vehicle to operate at a set speed.
This product does not require special parts such as bimetal thermostats, and can be completed at low cost by simply adding a program to a part of the microcomputer used to control the main unit. Also, as mentioned above, when the heating operation is restarted after the set time has elapsed, the indoor fan will be stopped for a certain period of time only if the room temperature is below the set value, and in other conditions, the indoor fan will rotate at a low speed. The discharge pressure does not rise abnormally, and the compressor does not lock, allowing comfortable cold air prevention.

As described above, in the present invention, if the room temperature is below the set temperature when the heating operation is restarted after the set time has elapsed, the indoor fan operates in the order of stop, low speed operation, and set speed, until the temperature exceeds the set temperature or When the heating operation is restarted within the set time, the indoor fan operates in the order of low speed operation and set speed, so that cold air can be prevented reliably and comfortably at low cost.

[Brief explanation of the drawing]

FIG. 1 is a refrigeration cycle diagram of an air conditioner to which the present invention is applied, and FIG. 2 is an explanatory diagram of the operation of an indoor fan for preventing cold air during heating in the air conditioner of the present invention. 1... Compressor, 2... Four-way valve, 3... Outdoor heat exchanger, 4... Capillary tube, 5... Indoor heat exchanger, 6... Indoor fan, 7... Outdoor fan.

Claims (1)

[Claims] 1. In a heat pump type air conditioner consisting of a compressor, a four-way valve, an outdoor heat exchanger, an indoor heat exchanger, etc. connected in sequence, the rotation speed for blowing air to the indoor heat exchanger is variable. If the indoor fan is equipped with an indoor fan and the room temperature is below the set temperature when heating operation is started, the indoor fan will be operated in the following order: stop - low speed operation - set speed, and return to heating operation when the temperature exceeds the set temperature or within the set time after stopping operation. An air conditioner control method characterized in that when restarting an air conditioner, an indoor fan is operated at a low speed and then at a set speed.