JPH025318Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to an air conditioner equipped with a refrigeration cycle having an electric expansion valve.

[Technical background of the invention]

Conventionally, in this type of air conditioner, operation is controlled on and off according to the indoor temperature, and the opening degree of the electric expansion valve is adjusted according to the refrigerant temperature or refrigerant pressure in the refrigeration cycle. The refrigerant flow rate is controlled, and the electric expansion valve is fully closed when the operation is turned off, and the electric expansion valve is fully opened when the operation is turned on, thereby minimizing heat loss. be.

[Problems with background technology]

However, when the operation is turned on, the electric expansion valve changes from the fully open state to the opening depending on the refrigerant temperature or refrigerant pressure, causing a delay in the start-up of the cooling or heating capacity by the time required for this change. There were flaws. Particularly, if the operation is turned on and off at short intervals, a satisfactory air conditioning effect cannot be obtained.

[Purpose of invention]

This idea was made in view of the above circumstances, and its purpose is to speed up the start-up of the cooling capacity or heating capacity when the operation is turned on, even if the interval between operation on and off is short. An object of the present invention is to provide an air conditioner with excellent practicality that can obtain a sufficient air conditioning effect even when the air conditioner is in use.

[Summary of the idea]

This idea stores the opening degree of the electric expansion valve up to that point when the electric expansion valve is fully closed when the electric expansion valve is turned off, and when the electric expansion valve is turned on, the electric expansion valve is first fully opened and then stored. This allows the opening to be varied.

[Example of idea]

An embodiment of this invention will be described below with reference to the drawings.

As shown in FIG. 1, a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, an electric expansion valve 4, an indoor heat exchanger 5
are sequentially connected to form a heat pump type refrigeration cycle. In this case, during the cooling operation, the refrigerant flows in the direction of the solid line arrow in the figure, and during the heating operation, the four-way valve 2 is switched, so that the refrigerant flows in the direction of the broken line arrow in the figure. Thus, an outdoor fan 6 is disposed near the outdoor heat exchanger 3, and an indoor fan 7 is disposed near the indoor heat exchanger 5. The electrically operated expansion valve 4 is capable of forward and reverse control and is capable of controlling the flow rate for both the cooling cycle and the heating cycle, and its opening degree changes depending on the supplied drive pulse. ing.

On the other hand, 8 is a drive control circuit that controls the supply of drive pulses to the electric expansion valve 4 according to the temperature detected by the refrigerant temperature sensor 9 attached to the refrigerant discharge side piping of the compressor 1. 4
It has a closing drive pulse counter 8a that counts the number of closing drive pulses supplied, and an opening drive pulse counter 8b that counts the number of opening drive pulses supplied. . Furthermore, the drive control circuit 8 corresponds to the compressor on/off control based on the indoor temperature of the main control section (not shown), and has the following functional means. That is, an indoor temperature thermostat 10 used for compressor on/off control is connected, and the indoor temperature thermostat 10
Means for forcibly fully closing the electric expansion valve 4 when the operation is turned off by responding to the operation of the counter 8a, 8b.
, and means for once fully opening the electric expansion valve 4 at the time of turning on the operation and then changing the opening degree in advance to the above-mentioned stored opening degree.

Next, the operation of the above configuration will be explained with reference to FIGS. 2 and 3.

When the cooling operation is set and the operation switch (not shown) is turned on, the drive control circuit 8 starts the counter 8.
A and 8b are forcibly cleared and their respective count values are set to the initial value "0". However, the indoor temperature is above the set value, and the indoor temperature thermometer
If it is on, the drive control circuit 8 supplies a specified number of opening drive pulses to the electric expansion valve 4 to fully open the electric expansion valve 4. In this case, counter 8b
does not count and maintains the initial value "0". When the electric expansion valve 4 is fully opened, the main controller turns on the compressor 1, forming a cooling cycle. In other words, cooling operation is started.

When the cooling operation is started, the drive control circuit 8 compares the temperature Td detected by the refrigerant temperature sensor 9 (hereinafter referred to as discharge refrigerant temperature) with a set value T, and controls the number of closing valves according to the comparison result. A driving pulse is supplied to the electric expansion valve 4, and the electric expansion valve 4 is changed from a fully open state to an opening degree corresponding to the discharge refrigerant temperature. From then on,
A closing drive pulse or an opening drive pulse is supplied to the electric expansion valve 4 in accordance with changes in the temperature of the discharged refrigerant, and its opening degree changes successively. At this time, counters 8a and 8b each count the number of drive pulses.

In this way, the indoor temperature decreases as a result of the cooling operation, and when the indoor temperature falls below the set value and the indoor temperature thermostat 10 is turned off, the drive control circuit 8 sends the electric expansion valve 4 to the predetermined number. A closing drive pulse is supplied to fully close the electric expansion valve 4. In this case, the counter 8a does not perform any counting and maintains the count value N before fully closing. Electric expansion valve 4
When the compressor 1 is fully closed, the main control section
turns off and cooling operation is interrupted. In this case, the electric expansion valve 4 is fully closed, thereby blocking the flow of the refrigerant, making it possible to suppress heat loss as much as possible. Also,
When the operation is turned off, the opening degree of the electric expansion valve 4 before it is fully closed is stored by the count value N of the counter 8a and the count value K of the counter 8b.

When the indoor temperature rises due to the operation being turned off, and when the indoor temperature reaches the set value and the indoor temperature thermostat 10 is turned on, the drive control circuit 8 supplies a specified number of opening drive pulses to the electric expansion valve 4, Electric expansion valve 4
Once fully opened. In this case, the counter 8b does not count, and the count value K before the operation is turned off is
maintain. When the electric expansion valve 4 is fully opened, the drive control unit 8 uses the count values N and K of the counters 8a and 8b to determine the opening degree H (=N-K) of the electric expansion valve 4 before the operation is turned off. calculate. That is,
The opening degree H is based on "0" (fully open state). Thus, a drive pulse corresponding to the opening degree H is supplied to the electric expansion valve 4, and the electric expansion valve 4
changes to the opening degree before operation is turned off. In this case, the counters 8a and 8b restart counting. When the electric expansion valve 4 finishes changing to the opening degree before turning off the operation,
The main control section turns on the compressor 1 and restarts the cooling operation. Thereafter, similar operations are repeated.

In this way, when the operation is turned on, the electric expansion valve 4 is fully opened in advance and then changed to the opening degree before the operation is turned off, so that when the operation is turned on, the electric expansion valve 4 immediately corresponds to the discharge refrigerant temperature. This allows the cooling capacity to ramp up quickly. Therefore, a sufficient cooling effect can be obtained even if the operation is turned on and off at short intervals.

Here, in FIG. 3, the solid line in the figure shows the indoor temperature change according to this invention, and the time delay Δt
It is clear that this does not occur.

In addition, although the above embodiment has been described using the cooling operation as an example, the same can be applied to the heating operation as well. In addition, a refrigerant temperature sensor 9 is attached to the refrigerant discharge side piping to control the refrigerant flow rate according to the discharge refrigerant temperature. Control may also be performed. In addition, this invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made without changing the gist.

[Effect of idea]

As mentioned above, according to this invention, it is possible to accelerate the start-up of cooling capacity or heating capacity when operation is turned on, and even if the interval between operation on and off is short, a sufficient air conditioning effect can be obtained. We can provide air conditioners with excellent performance.

[Brief explanation of drawings]

The drawing shows one embodiment of this invention.
The figure is an overall schematic configuration diagram, FIG. 2 is a flowchart for explaining the operation, and FIG. 3 is a diagram showing changes in indoor temperature. DESCRIPTION OF SYMBOLS 1...Compressor, 4...Electric expansion valve, 8...Drive control circuit, 9...Refrigerant temperature sensor, 10...Indoor temperature thermometer.

Claims (1)

[Scope of utility model registration request] An air conditioner that is equipped with a refrigeration cycle having an electric expansion valve, and controls the operation on and off according to the indoor temperature, and adjusts the opening degree of the electric expansion valve according to the refrigerant temperature or refrigerant pressure of the refrigeration cycle. In the machine, means for fully closing the electric expansion valve when the operation is turned off, means for storing the opening degree of the electric expansion valve before the fully closing, and means for fully opening the electric expansion valve once when the operation is turned on. and means for changing the opening degree in advance to the stored opening degree.