JPS6115970B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a ventilation control device for an air conditioner equipped with a ventilation function, and contributes to energy saving.
Moreover, it provides comfortable air conditioning control.

A conventional ventilation control device for an air conditioner is as shown in the timing chart in Figure 1. This system detects the indoor temperature and opens and closes the compressor to keep the indoor temperature constant, taking into account the outside temperature conditions.When the outside temperature drops below a certain temperature, the cooling function is forcibly stopped and the outside air is turned off. The system switches to ventilation operation using a fan motor.

This method switches to a so-called wind fan by switching to ventilation operation when the outside air temperature drops below a certain temperature, so it maintains a certain cooling effect.
Although it has an energy-saving effect, it does not take into account the ON/OFF conditions of the thermostat depending on the indoor temperature, so it has the disadvantage that the cooling effect cannot be obtained when the user desires a lower indoor temperature. When the temperature setting is satisfactory, there is a drawback that if the outside air temperature is higher than the set outside air temperature, the ventilation effect cannot be obtained.

It also has the disadvantage that the ventilation damper chatters when the detected outside temperature is around the set temperature. As a conventional example, there is a device in which hysteresis is provided for outside temperature detection, but there is a problem that providing stable hysteresis reduces the outside temperature detection accuracy.

The present invention solves the above-mentioned drawbacks by appropriately switching between ventilation operation and cooling operation by combining indoor and outdoor temperatures and three different times using a fixed timer, thereby achieving economical and comfortable air conditioning. It has been made possible.

Hereinafter, a ventilation control device for an air conditioner according to an embodiment of the present invention will be described with reference to the drawings from FIG. 2 onwards.

FIG. 2 shows an example of a circuit for realizing this embodiment.
1 is a P-channel MOS type microcomputer forming a central control circuit, 2 is a thermistor for detecting indoor temperature, 3 is a variable resistor for setting indoor temperature, 4, 7
is the voltage comparator, and 5 is the indoor temperature thermostat.
Hysteresis resistor for setting ON/OFF width, 6
are thermistors that detect the outside temperature, 8, 10, 12
is a transistor inverter that drives relay coils 9, 11, 13, relay coils 9, 11, 13
These are used to drive the compressor that constitutes the refrigeration cycle, the ventilation damper that constitutes the ventilation device, and the fan motor of the indoor and outdoor blower, respectively, which together with the outdoor heat exchanger, pressure reduction device, and indoor heat exchanger constitute the refrigeration cycle.

The indoor temperature thermostat circuit, which is composed of thermistor 2, variable resistor 3, resistor 5, comparator 4, and peripheral resistance, sends a high level signal to the input Iφ of microcomputer 1 when the indoor temperature is higher than the setting, and when it is lower than the setting. input a low level signal.
Similarly, an outside temperature determination circuit composed of a thermistor 6, a comparator 7, and a peripheral resistor inputs a high level signal to the input _I1 of the microcomputer 1 if the outside temperature is higher than the set value, and a low level signal if it is lower than the set value.

Relay coils 9, 11 and 13 are driven via transistor inverters 8, 10 and 12 by outputting high level signals to outputs Oφ, O1 and O2 of microcomputer 1, respectively.

Next, the operation will be explained using a flowchart in FIG. 3 and a timing chart in FIG. 4.

Cooling operation is started, and normal cooling operation is performed without performing outside air determination for a second predetermined time (hereinafter referred to as time _T2 ) of the fixed time timer. After time T ₂ has elapsed, if the room temperature thermostat circuit (hereinafter referred to as "thermo") is ON, cooling continues and the thermostat is turned off.
When the outside temperature reaches
) is determined by the outside temperature determination circuit.
Also, if the thermostat is off, the outside air is immediately determined. If the outside air temperature is high, normal cooling operation will be turned on and off.
However, if the outside air is low, relay coil 1
1 to open the ventilation damper and enter the ventilation operation state using the fan motor.

Here, a first predetermined time T ₁ (hereinafter referred to as time T ₁ ) of a fixed time timer is provided to ensure the shortest ventilation operation time. Time _T1 serves as a limit timer to prevent chattering due to subtle fluctuations in the detected outside temperature and to ensure restart of the compressor.

The relay coil 11 is energized and the ventilation operation is started, and the ventilation operation is continued unconditionally for a time _T1 , and after the time _T1 has elapsed, it is determined whether the thermostat is ON or OFF. If the thermostat is ON, the relay coil 11 is immediately energized to close the ventilation damper, and the relay coil 9 is energized to turn on the compressor and shift to cooling operation. (At this point, time _T2 is reset.) If the thermostat is OFF here, ventilation operation will continue. However, even if the outside air temperature is high during this time, the ventilation damper will remain open. This is because if the indoor temperature is below the user's desired temperature, continuing ventilation even if the outside temperature is slightly higher than the set temperature will increase the overall ventilation effect and will not deteriorate the air conditioning feeling.

Next, after time T ₂ has passed, ventilation operation is not performed until time T ₃ (T ₂ < T ₃ here) because the outside temperature is higher than the setting or the thermostat remains on. Let me explain the case. In this case, after time _T3 has elapsed, the ventilation operation is shifted to even if the outside temperature is high. As for the timing of transition to ventilation operation, as shown in FIGS. 3 and 4, the compressor is forcibly stopped and the ventilation operation is transitioned to synchronization with time _T2 . The return from ventilation to cooling operation depends on the output of the thermostat after the aforementioned time _T1 .
This is because if the cooling operation is continued for a certain period of time, the indoor air will gradually become polluted since the air conditioning only relies on the circulation of indoor air, so it is better to ventilate the room at regular intervals.

Regarding the timing of ventilation, if the output of the thermostat is taken into account, the thermostat may not turn off during high loads, so it will be forced to be synchronized with time _T3 .

As is clear from the description of the embodiments above, according to the ventilation control device for an air conditioner of the present invention, during normal cooling operation, the indoor temperature drops to the set value after the second predetermined time has elapsed, and the thermostat is turned off. At this point, the outside temperature is detected for the first time, and a decision is made as to whether or not to enter ventilation operation. As a result, when the indoor temperature becomes sufficiently stable, natural cooling can be performed using outside air without impairing the user's feeling, contributing to energy saving and air purification. In addition, after a certain period of time set by a timer for stabilizing performance and protecting the compressor, it detects whether the thermostat is ON or OFF.
It can detect whether or not cooling operation is to be started, and if the thermostat is off, ventilation continues, which has the effect of ensuring a sufficient air conditioning temperature and providing the maximum air purification function. In addition, if the outside temperature is higher than the setting or the cooling load is large and the thermostat does not turn off, the ventilation operation is forced to continue for the first predetermined time after the third predetermined time has elapsed. is possible. This provides energy saving and air purification functions under all operating conditions.

Therefore, the present invention can ensure sufficient ventilation efficiency and air purification function without impairing the temperature control effect at any set temperature, while satisfying the desired indoor temperature conditions. This has extremely significant effects such as increasing the accuracy of outside temperature detection.

[Brief explanation of the drawing]

Fig. 1 is a timing chart of a conventional air conditioner ventilation control device, Fig. 2 is an electrical circuit diagram of an air conditioner ventilation control device according to an embodiment of the present invention, and Fig. 3 is a flowchart of the ventilation control device. Chart diagram, Figure 4 is the timing chart diagram of the same ventilation system, Figure 5
The figure is a block diagram showing the present invention in terms of functional implementation means. 1... Microcomputer (central control circuit), 2... Thermistor, 6... Thermistor, 9
... Relay coil for compressor, 11 ... Relay coil for ventilation system (ventilation circuit), 13 ... Relay coil for fan motor.

Claims (1)

[Claims] 1 A compressor that constitutes a refrigeration cycle, a ventilation system, a thermostat that detects the indoor temperature and controls the operation of the compressor to control the indoor temperature, and an outside temperature that determines the high or low of the outside air temperature by setting a fixed point. It has a determination circuit and a fixed time timer that sets first, second, and third predetermined times, respectively, and when the second predetermined time has elapsed after the start of cooling operation and the thermostat is turned off, A temperature determination circuit determines whether the outside air temperature is high or low, and if the detected outside air temperature at this time is lower than the fixed point setting, a first operation is performed to operate the ventilation device during a first predetermined time of the fixed time timer. and a control means that determines the output of the thermostat after the first predetermined time has elapsed, and if the output of the thermostat is ON, the compressor is operated, and if the output of the thermostat is OFF, the ventilation device continues to operate. a second control means, and a third control for forcing ventilation operation after the third predetermined time has elapsed if the ventilation operation has not been performed by the elapse of the third predetermined time of the fixed time timer after the start of the cooling operation. A ventilation control device for an air conditioner having a central control circuit having means.