JPS6356452B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an air conditioner that operates a compressor while controlling its capacity by comparing the actual air temperature in an air-conditioned area with a set temperature, thereby enabling temperature control with a small fluctuation range. .

Many devices are used that periodically detect the temperature of the blown air and perform air conditioning to maintain a constant room temperature while controlling the capacity of the compressor. As in the disclosed device, the capacity controller is deactivated until the air temperature first reaches a predetermined thermostat setting after startup, thereby reducing the startup time at startup. Usually, the control circuit is configured in the

For example, a compressor has a large number of steps (usually 5 to 9).
Step) If you are using a device that enables stepwise capacity control, if you start it up in the low capacity range,
If the capacity is controlled periodically or in stages, it may take a long time to reach a capacity range commensurate with the load, or it may be impossible to quickly reach the desired temperature range, which has the disadvantage of causing discomfort. be.

Therefore, at startup, the engine operates at 100% capacity, and from the moment the blown air temperature reaches a predetermined temperature, normal periodic, step-by-step capacity control is performed.

However, when the air conditioning load is small,
If it is started at 100% capacity, the predetermined set temperature will be exceeded, resulting in the phenomenon of being too cold in the case of cooling and too hot in the case of heating, and then reaching the predetermined temperature through step capacity control. There was an inconvenience.

As described above, the present invention was developed by paying attention to the problems that occurred with conventional devices, especially during startup, and its purpose is to shorten the warming-up time during startup operation, and
The purpose is to quickly reach a compression function commensurate with the load and perform air conditioning operation with a small temperature fluctuation range, thereby ensuring and easily obtaining a comfortable environment.

To this end, the present invention provides a compressor capable of controlling the capacity, a capacity controller capable of controlling the capacity of the compressor in stages, a temperature detection means for detecting the air temperature in an air-conditioned area, and a temperature detection means that Capacity control command means for periodically and repeatedly comparing the detected temperature and a set temperature having a temperature band, and selecting and issuing a corresponding one of a capacity increase signal, a capacity decrease signal, and a current capacity maintenance signal; If the signal issued by the capacity control command means is a capacity increase signal or a capacity decrease signal, the capacity control unit increases the capacity by one stage or increases the capacity by one level.
A capacity control output means that provides a step control output for stage reduction, while maintaining the capacity controller in the current control output state if the current capacity maintenance signal is present; The controller is operated at a capacity intermediate between the maximum capacity and the minimum capacity, and a signal is issued to the capacity control command means to shorten the period for temperature comparison, and this signal is used to issue a current capacity maintenance signal. The air conditioner is equipped with a switching means 6 that continues to switch to the point where the cycle continues and then releases the cycle to restore the cycle.By starting at an intermediate capacity at the time of startup, It is possible to quickly reach a capacity commensurate with the load without any problems, and it is also possible to eliminate the overrun phenomenon that exceeds the set temperature range, thereby achieving the above-mentioned purpose.

Hereinafter, embodiments of the air conditioner of the present invention will be described in detail based on the drawings.

The air conditioner according to the embodiment of the present invention shown in FIG. 1 includes a compressor 1 consisting of two compressors 1A and 1B whose capacity can be controlled in stages by the operation of a capacity controller 2. For example, using a 6-cylinder reciprocating compressor, the low-pressure suction gas passage in the compressor casing is divided into two so that each three cylinders can take in suction, and one of the three cylinders' suction passage can be opened and closed to achieve 100% and This enables 50% operation.

By combining these two compressors 1A and 1B, the capacity controller 2 operates to operate both at maximum (first stage) capacity at 100%, one at 100% and the other at 50%. The ability of the second stage, the ability of the third stage to operate both at 50%, the ability of the fourth stage to operate only one at 100%, the ability of the fifth stage to operate only one at 50%. The so-called 6 is obtained by adding full stop to the stage ability.
Step-by-step capacity control is possible.

In the cooling operation of this device, the gas discharged from the compressor 1 is condensed and liquefied in a condenser (not shown), and then reduced in pressure in a pressure reducer to form a low-pressure refrigerant liquid and sent to the evaporator 7 having two paths. After the heat of evaporation is exchanged with the indoor return air, it is returned to the compressor 1, and is configured to have two independent refrigerant circuits.

The indoor return air cooled in the evaporator 7 is then sent into the room through an air supply duct 9 by an indoor fan 8.

In such cooling operation, the temperature control that maintains the room temperature constant by the signal from the temperature sensing means 3 which detects the air temperature in the area to be cooled, for example, the temperature of the cold air in the air supply duct 9, is carried out by the above-mentioned compression. This is done under the control of the machine's capabilities.

This control system will be explained with reference to FIGS. 1 to 3. The temperature sensor 3 is used as an input signal element, the capacity controller 2 is used as an output element, and a capacity control command means 4, for example, a three-stage command type thermostat, A control circuit 10 is provided.

The three-stage command type thermostat (hereinafter abbreviated as thermostat) 4 is a temperature controller whose set temperature points differ by several degrees and each has a differential of about 1 degree Celsius, as illustrated in Fig. 3. Using 4A and 4B, when both high temperature side 4A and low temperature side 4B operate and close the contact (ON), this is used as a capacity increase signal, while high temperature side 4A is inactive and opens the contact. (OFF) and when the low temperature side 4B operates and closes the contact (ON), this is used as the current capacity maintenance signal, and both the high temperature side 4A and the low temperature side 4B are inactive and the contact is closed (ON). When it is opened (OFF), this is used as a capacity reduction signal, and one of these three signals corresponds to the height of the air temperature in the area to be air conditioned (in this example, the blowout air temperature). The command is selected and issued periodically (usually every 3 minutes) in combination with a timer circuit.

The thermostat 4 that operates as described above is of course for cooling purposes, and it goes without saying that for heating purposes, the capacity increase signal and capacity decrease signal may be interchanged.

Next, the control circuit 10 is shown as a block diagram in FIG. 2, and consists of a capacity control output means 5 and a switching means 6. If the signal from the thermostat 4 is a capacity increase signal or a capacity decrease signal, a step control output is issued for one step increase or one step decrease. is issued to the capacity controller 2, while if it is a current capacity maintenance signal, an output is issued to maintain the capacity controller 2 in its current control output state.

On the other hand, the switching means 6 controls the capacity controller 2 to set the capacity to the maximum capacity (100%+100%) in response to a command signal S for starting the compressor 1 from a stopped state, for example, when a temperature control switch is closed. Minimum capacity (0
% + 0%) (for example, 50% + 50%), and sends a signal to the timer circuit of the thermostat 4 to shorten the period for temperature comparison, for example, the period T ₀ is normally 3 minutes. Period of 1 minute T ₁
It is becoming shorter.

This shortening signal is continued from the start of operation until the time when the signal of the thermostat 4 switches from the capacity increase signal to the current capacity maintenance signal, and then is released. is restored to operate at the normal period T ₀ .

The cycle can be shortened in this way simply by changing the discharge time constant for timing in an electronic timer circuit consisting of a capacitor and a resistor.

The cooling operation of the air conditioner having the above configuration is performed as follows.

When the temperature control switch is closed (see Fig. 4), the compressor 1 starts up, but at that time, as mentioned above, the switching means 6 operates and the compressor 1 changes to (50% + 50%).
%) at the intermediate capacity and at the same time the thermometer 4
The sample period for temperature comparison can be shortened from 3 minutes to 1 minute.

Therefore, as shown in Fig. 5, the short period (T ₁ = 1
As a result of repeated comparisons between the suction air temperature and the set temperature (minutes), the step control for increasing the capacity by one stage is quickly performed while the capacity increase signal is being issued.

In this case, when the cooling load is large, the maximum capacity is naturally reached quickly, while when the cooling load is small, the room temperature quickly reaches the set temperature, so the capacity increase signal is switched to the current capacity maintenance signal by the time the maximum capacity is reached.

In this way, at the same time that the signal issued by the thermostat 4 switches to the current capacity maintenance signal, the thermostat 4 restores the sampling period from 1 minute to 3 minutes, and thereafter performs temperature comparison every 3 minutes. Compressor capacity control is performed in accordance with the type of signal issued by the thermostat 4, and a capacity suitable for the load is quickly selected to provide cooling operation with fewer starts and stops and a stable temperature.

Furthermore, since the compressor is started at an intermediate capacity, sudden suction of refrigerant does not occur, and therefore, problems such as damage to the compressor due to liquid bag do not occur.

Incidentally, although the above-mentioned embodiments have been described with respect to cooling operation, it goes without saying that the present invention can also achieve temperature control in heating operation using the same structure and operation, and can be applied to heat pump type air-conditioning devices and the like.

Next, the effects of the present invention are as follows.

() Since the engine is operated at an intermediate capacity rather than the maximum capacity when starting, it is possible to eliminate the overrun phenomenon that tends to occur when operating at excessive capacity.

() When the load is large, the step capacity is increased in short cycles from the intermediate capacity after startup, so the maximum capacity operation is quickly reached and the warm-up time is shortened.

() By shortening the sampling period at startup, the capacity commensurate with the load is quickly reached, resulting in extremely high comfort.

() After the rapid capacity control after startup is completed, the sampling period is returned to the normal state, so short-term repetitions of starting/stopping the compressor 1 and changing the capacity do not occur, resulting in economical operation. performance and reliability are improved.

() Since it is started at intermediate capacity, it is possible to prevent liquid back up.

[Brief explanation of the drawing]

Each figure shows an aspect of an embodiment of the present invention, and FIG. 1 is a schematic structural diagram, FIG. 2 is a control circuit block diagram, and FIG. 3 is an explanatory diagram of the operation of the capacity control command means in FIG. 2. FIG. 4 is a flowchart relating to the switching means of the control circuit shown in FIG. 2, and FIG. 5 is an operation explanatory diagram showing changes in the temperature of the blown air with respect to operating time. DESCRIPTION OF SYMBOLS 1... Compressor, 2... Capacity controller, 3... Temperature detection means, 4... Capacity control command means, 5... Capacity control output means, 6... Switching means.

Claims (1)

[Claims] 1 A compressor 1 whose capacity can be controlled, a capacity controller 2 which can control the capacity of the compressor 1 in stages, a temperature detecting means 3 which detects the air temperature in an air-conditioned area, and this temperature detecting means 3 Capacity control command means 4 that periodically and repeatedly compares the detected temperature with a set temperature having a temperature band, and selects and issues a corresponding one of a capacity increase signal, a capacity decrease signal, and a current capacity maintenance signal; If the signal issued by the capacity control command means 4 is a capacity increase signal or a capacity decrease signal, a step control output of one step increase or one step decrease is given to the capacity controller 2, while a current capacity maintenance signal is issued. If so, the capacity control output means 5 maintains the capacity controller 2 in the current control output state, and the capacity control output means 5 controls the capacity controller 2 between the maximum capacity and the minimum capacity in conjunction with starting the compressor 1. At the same time, a signal is issued to the capacity control command means 4 to shorten the period for temperature comparison, and this signal is continued until the time when the current capacity maintenance signal is issued, and then released. and a switching means 6 for restoring the period.