JPS596350Y2 - Air conditioning compressor control device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a control device for a compressor used in an air conditioner.

A commonly used air conditioner has a compressor 1 as shown in Figure 1.
, heat source side heat exchanger 2, pressure reducing device 3, and user side heat exchanger 4
For example, when the compressor 1 is operated, the refrigerant flows in the direction of the solid arrow, so that the heat source side heat exchanger 2 acts as a condenser, and the user side heat exchanger 4 acts as an evaporator. The heat exchanger 4 is used to cool an air-conditioned room (not shown).

Conventionally, in such air conditioners, a room temperature thermostat is used to compare the temperature of the conditioned room (hereinafter referred to as room temperature) with the thermoset temperature and control the compressor motor on and off, thereby keeping the room temperature close to the set temperature. I try to keep it that way.

In this case, regardless of whether the thermostat is mechanical or electronic,
Two-point control temperature TON, TOFF, on point and off point
is usually determined, and the difference between the two is called the differential.

However, with this system, when the load is small, the room temperature drops rapidly due to the operation of the compressor 1, as shown in Figure 2.
Room temperature is the off-point control temperature T.

The on-point control temperature T after the compressor 1 is stopped significantly below FF.

Not only does it take a long time to reach N, which substantially widens the differential, but when the load is large, the room temperature is lower than the off-control temperature TO, as shown in Figure 3.
The time from when FF is reached and the compressor 1 is stopped until the room temperature reaches the ON control temperature is shortened, and the compressor 1 may be forced to start without the pressure balance of the refrigerant circuit 5 being maintained. Ta.

Especially in the latter case, there is a risk of damaging the compressor 1.
A thermostat and a separate timer device had to be installed to prevent forced starting.

The present invention was developed in view of the above facts, and includes a temperature controller that can be adjusted arbitrarily, a room temperature sensor that detects the temperature of the air-conditioned room, and a judgment device that controls on/off the compressor motor. This judgment device includes a comparison means for comparing the output signals of the temperature controller and the room temperature sensor, an off command means for turning off the compressor motor based on the output of the comparison means, and an off point that is stored in advance according to the load condition. an off-time setting means for adjusting the time from to an on-point; an on-command means for turning on the compressor motor with the output of the comparison means after the off-time has elapsed; and outputs of the on-command means and the off-command means. By using output discrimination means that turns on and off the compressor motor by determining the An object of the present invention is to provide a control device for an air conditioning compressor that can prevent forced starting of the air conditioning compressor.

An embodiment of the present invention will be described below based on the drawings.

FIG. 4A shows an outline of the device of the present invention, and 6 is a temperature regulator that can be adjusted arbitrarily by operating buttons (not shown);
7 is a room temperature sensor that detects the room temperature, 8 is an outside temperature sensor that detects the outdoor temperature, and 9 is a liquid pipe temperature sensor that detects the outlet side piping temperature of the heat source side heat exchanger 2, which serves as a condenser during cooling of the refrigerant circuit 5. , 10 is a gas pipe temperature sensor that detects the outlet side piping temperature of the user-side heat exchanger 4, which also serves as an evaporator, 11 is a DC power supply, and 12 is a temperature signal from each sensor and a temperature controller 6.
This is a determination device that converts the set temperature of A comparing means 16 for comparing the output signal with the room temperature sensor 7, and a compressor motor 14 using the output of this comparing means.
off command means 17 for turning off the OFF command, off time setting means 18 for adjusting the time from the OFF point to the ON point according to the load condition, which is stored in advance; and the comparison means 1 after the lapse of the OFF time
ON command means 1 for turning on the compressor motor with the output of 6
9, and an output discrimination means 20 that discriminates the outputs of the on command means and the off command means 17 to turn on and off the compressor motor 14, and the main part is a one-chip or several-chip LSI ( It consists of a microcomputer consisting of a large-scale integrated circuit.

15 is the compressor motor 14 when the output switch 13 is closed.
It is an AC power source that conducts electricity.

During cooling operation, while the room temperature is higher than the set temperature of the temperature controller 6, the comparison means 16 → ON command means 19 → output discrimination stage 20
The output switch 13 is closed with the output of the compressor motor 1.
4 is in operation, and indoor air is cooled by the user-side heat exchanger 4.

And the room temperature is the set temperature T.

When the output voltage drops below , the output switch 13 is opened by the output of the comparison means 16→off command means 17→output determination means 20, the power supply to the compressor motor 14 is cut off, and the cooling operation is stopped.

At this time, the off-time setting means 18 detects the outdoor temperature by the outdoor temperature sensor 8, and when the difference between the outdoor temperature and the set temperature is small (during light load), the set temperature T is set as shown in FIG.
.

The off time t is approximately equal to the length obtained by subtracting the time t1 below the off time t'OFF from the off time t'OFF in FIG.

When the FF is determined, and the difference is large (at the time of overload), the off time t is preset as shown in Figure 6. ,
Since the compressor motor 14 is restarted after the off time in which the pressure of the refrigerant circuit 5 is balanced, forced startup can be reliably prevented.

In this way, the off time setting means 18 detects the load condition and determines the off time from the off point to the on point, so the effective differential is kept constant and the on/off control temperature is determined in advance. This method keeps the room temperature more uniform.

Also, when the outdoor temperature drops and the load becomes light, or when the set temperature is increased, the off time t OF
If F is set long, the room temperature can be kept close to the set temperature.

In the above-described embodiment, the load condition is detected by inputting the outdoor temperature. A temperature difference or the like may be detected as an input.

In addition, the off time from the off point to the on point is determined according to the load condition, but the off time is set so that the on point control temperature is low when the load is light, and the on point control temperature is high when the load is overload. Even if the means 18 is activated, a substantial differential can be maintained and forced starting of the compressor can be prevented.

Furthermore, I explained the case where the air conditioner operates in cooling mode.
The same applies to heating operation.

As mentioned above, the present invention includes a temperature regulator that can be adjusted arbitrarily;
The judgment device includes a room temperature sensor that detects the temperature of the air-conditioned room and a judgment device that controls on/off of the compressor motor, and the judgment device includes a comparison device that compares the output signals of the temperature controller and the room temperature sensor, and a comparison device that compares the output signals of the temperature controller and the room temperature sensor. an off command means for turning off the compressor motor with the output of the off-time setting means that is stored in advance and adjusts the time from the off point to the on point according to the load condition; and an output of the comparison means after the off time has elapsed. The system consists of an on-command means for turning on the compressor motor at a given time, and an output discriminating means for discriminating the outputs of the on-command means and the off-command means and turning on the compressor motor. The optimum off-time or on-control temperature is adjusted, the differential is effectively prevented from widening, the room temperature is maintained near the set temperature, and damage caused by forced starting of the compressor can be prevented. The present invention provides a high quality air conditioning compressor control device.

[Brief explanation of the drawing]

Figure 1 is a refrigerant circuit diagram of a general air conditioner, Figures 2 and 3
The figure is an explanatory diagram showing the operating state of the conventional device, FIG. 4A is an electric circuit diagram showing an embodiment of the present device, FIG. FIG. 3 is an explanatory diagram showing the operating state of the device of the present invention. 5... Refrigerant circuit, 6... Temperature controller,
7... Room temperature sensor, 8... Outside temperature sensor, 12... Judgment device, 14... Compressor motor.

Claims (1)

[Scope of utility model registration request] In an air conditioner equipped with a refrigerant circuit in which a compressor, a heat source side heat exchanger, a pressure reducing device, a user side heat exchanger, etc. are connected, a temperature controller that can be adjusted arbitrarily and the temperature of the air conditioned room is detected. It is equipped with a room temperature sensor and a judgment device for controlling on/off of the compressor motor, and this judgment device includes a comparison means for comparing the output signals of the temperature controller and the room temperature sensor, and a comparison means for comparing the output signals of the temperature controller and the room temperature sensor, and a comparison device that controls the compressor motor based on the output of the comparison means. an off command means for turning off the compressor; an off time setting means that is stored in advance and adjusts the time from the off point to the on point according to the load condition; and after the off time has elapsed, the compressor motor is turned on by the output of the comparison means. 1. A control device for an air conditioning compressor, comprising: an on-command means for turning on the compressor; and an output discriminating means for discriminating the outputs of the on-command means and the off-command means to turn on and off the compressor motor.