JPS6365244A - Controller for air-conditioning machine - Google Patents

Abstract

PURPOSE:To prevent the deterioration of heating capacity, by a method wherein defrosting is effected without waiting for the arrival of the accumulating time of operation of a compressor at a predetermined value when the frosting speed of an outdoor heat exchanger is quick. CONSTITUTION:A first timer 7 totalizes the operating time of a compressor 1, however, when frosting speed is quick and the temperature of an outdoor heat exchanger has becomes lower than a predetermined value at a time T1' before the accumulating time of the operation of the compressor arrives at a predetermined value, a first temperature detecting circuit 9 outputs an H signal and a second timer 10 accumulates the time of continuation of the H signal. When an accumulated time or (t1+t2) has arrived at the predetermined value at the time point of T2', the second timer 10 outputs the H signal. When an atmospheric temperature is higher than the predetermined value, the second temperature detecting circuit 14 outputs the H signal. When two signals are inputted, an AND circuit 15 outputs the H signal and puts a relay 18 OFF by a driver 17 through an OR circuit 16, therefore, a four-way valve 2 is closed and defrosting is started.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control device for an air conditioner, and in particular to defrosting control thereof.

Conventional technology 2B-7 Conventionally, defrosting control has been performed to prevent reduction in heating capacity due to frost formation on the outdoor heat exchanger during heating operation in air conditioners capable of cooling and heating. Therefore, optimization of defrost control is required.

The conventional air conditioner control device described above will be described below with reference to the drawings.

FIG. 4 is a diagram of a refrigeration system of a conventionally used general air conditioner.

In Fig. 4, 1 is a compressor, 2 is a four-way valve, 3 is an indoor heat exchanger, 4 is a throttle valve, and 6 is an outdoor heat exchanger, which are connected in sequence to form a refrigeration cycle. By selectively switching the flow direction of the refrigerant with the valve 2, heating or cooling operation is performed. The arrow - in the figure indicates heating;
...- indicates the flow of refrigerant during cooling.

In addition, in such an air conditioner, during heating operation, the outdoor heat exchanger 5, which serves as an evaporator, may have a sheath attached to it and freeze.

For this reason, generally, when the cumulative operating time of the compressor 1 reaches a predetermined time and the temperature of the air-to-air heat exchanger 3-76 falls below a predetermined value, it is assumed that frost has formed and a defrost signal is output. By switching the four-way valve 2 in response to this defrosting signal, the frost adhering to the outdoor heat exchanger 6 is removed using high-temperature gas in a cooling cycle, and when this is completed, the temperature of the outdoor heat exchanger 6 is set to a predetermined level. When the temperature exceeds the value, a defrosting end signal is output, the four-way valve 2 is switched, and the heating cycle is returned to the heating operation.

Problems to be Solved by the Invention However, the above configuration has the following problems. That is, when the outside air condition is high humidity, the speed at which frost adheres to the outdoor heat exchanger 5 is fast, and the temperature of the outdoor heat exchanger 5 falls below a predetermined value in a short time, but the cumulative operating time of the compressor 1 does not exceed the predetermined value. Defrosting is delayed because the temperature is not reached, resulting in an extremely low heating capacity, which has the drawback of not being able to provide comfortable air conditioning.

Means for Solving the Problems In order to solve the above problems, the air conditioner control device of the present invention has a first timer that integrates the operating time of the compressor and a temperature of the outdoor heat exchanger that serves as the evaporator during heating. a first temperature detection circuit that detects the outside air temperature; a second temperature detection circuit that detects
and the temperature of the evaporator is below a predetermined temperature, or the second
The cumulative time of the timer reaches a predetermined value, and the outside air? i,
When a7Jl is greater than a predetermined value, the ratio 11 to the evaporator is
The present invention has the above-described configuration, so that when the speed of frost formation on the outdoor heat exchanger is fast, the operating product of the compressor between 3i and ns7 reaches a predetermined value. Dividing 1i is performed without waiting for the arrival of the value.

Embodiment Below, a control device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3. The general operation of the refrigeration cycle is the same as that of the conventional example, and will therefore be omitted. Components that are the same as those in the conventional example will be described using the same reference numerals.

5 In the vane M1 diagram, 6 is a compressor operation signal generation circuit that generates an operation signal for the compressor 1, and 7 is a first timer that receives the compressor operation signal and totalizes the operating time, which outputs an output when a predetermined value is reached. outputs a high level signal (hereinafter abbreviated as H signal). 8 is M1 attached to the outdoor heat exchanger 5 which serves as an evaporator.
A temperature detection element 9 is a first temperature detection circuit which receives the output of the temperature detection element 8 as input and detects the temperature of the unexpected heat exchanger 5, and outputs an H signal when the temperature falls below a predetermined value. 1o is a second timer which inputs the output of the first temperature detection circuit 9 and integrates the time when the output of the first temperature detection circuit 9 becomes an H signal, that is, the temperature of the outdoor heat exchanger 5 becomes below a predetermined value. , outputs an H signal when it reaches a predetermined value. 11 is an AND circuit which receives the output signal of the first timer 7 and the output signal of the first temperature detection circuit 9, and outputs an H signal only when both inputs are H signals, and 12 is the AND circuit. Flip 70 tube (F, F) that inputs the output signal of 11 to the set terminal S
, 13 is a second temperature detection element that detects the outside air temperature of the outdoor heat exchanger 5, and 14 is a second temperature detection circuit that uses the second temperature detection element 13 manually to detect the outside air temperature. The output signals 3 and 15 receive the output signal of the second temperature detection circuit 14 when the output of the second timer 1o is received, and output the H signal only when both inputs are H signals. The AND circuit 16 that outputs the bow inputs the output signals of F and F12 and the output signal of the AND circuit 15, and outputs H (i'?
17 is a driver that drives the relay 18, and the four-way valve 2 is connected to the power supply 19. 1 and 2o are the input terminals for the first temperature detection element 8. A reset signal that outputs a control signal when the temperature of the outdoor heat exchanger 6 exceeds a predetermined value, and the reset signal is the first timer 7, the second timer 1o, F, F1.
It is input to the reset terminal R of 2 and each timer and F, F12.
7.

The operation of the above configuration will be explained below with reference to the time charts of FIG. 2 and FIG. 3-2. Fig. 2 Defrosting pattern when the frosting speed is slow Tea 7 Pagely, compressor operation signal from the compressor operation signal generation circuit 6 (
H signal) is integrated by the first timer 7, and when it reaches a predetermined value at time T1, the first timer 7 continues to output the H signal.

After that, frost builds up on the outdoor heat exchanger 5 and the temperature decreases.
When the predetermined temperature (e.g. -5°C) is reached at point 2, the first
Temperature detection circuit 9 outputs an H signal. The AND circuit 11 which inputs the output signal of the first timer 7 and the output signal of the first temperature detection circuit 9 outputs an H signal as an output since both signals are H, and sets the output signal of the AND circuit 11. The input F and F12 output an H signal. The H signal output from F and F12 is passed through the R circuit 16 to turn off the relay 18 by the dry nozzle 17, so the four-way valve 2 is no longer energized by the power source 19 and is turned off.

When the four-way valve 2 is turned off, the flow of the refrigerant is reversed, and the outdoor heat exchanger 5 is defrosted by the high-temperature gas. The temperature of the outdoor heat exchanger 5 rises to a predetermined temperature (for example, 1
At the time of T3 when reaching 0'C), "',, H:'j,',
+ y) lEj] @ 2 oka8□□kaka1, □,
2E′]I′ and F, F12 as Lee-k,)-) L
, four-way valve, is turned on and returns to heating mode.

Figure 3 shows a defrosting pattern when the outside air is highly humid and the frosting speed is fast.As mentioned above, the first timer 7 integrates the operating time of the compressor 1, but when the frosting speed is fast and the At time T1' before the accumulated machine operation time reaches the predetermined value, the temperature of the outdoor heat exchanger 6 becomes below the predetermined value, the first temperature detection circuit 9 outputs the H signal, and the second timer 10 outputs the H signal. Accumulate the duration. At the time of T2', the cumulative time part'(
tl +t, 2) reaches a predetermined value, the second timer 1
o outputs an H signal. Further, when the outside temperature is above a predetermined value, the second temperature detection circuit 14 outputs an H signal. Since both the output signal of the second timer 10 and the output signal of the second temperature detection circuit 14 are H signals, the AND circuit 16 which receives these two signals as input outputs an H signal as an output.

The output of the AND circuit 15 is transmitted through the OR circuit 16 to the driver 17 to turn off the syringe relay 18 as described above, so the four-way valve 2 is turned off and defrosting is started.

At time T3' when defrosting is finished and the temperature rises, the reset circuit 20 outputs an H signal, and the four-way valve 2 is turned on by resetting the 29th page timer 1o, as described above.

Therefore, defrosting ends and the heating mode returns. When the outside temperature is below a predetermined value, the second temperature detection circuit 14 does not output an H signal, so defrosting does not begin as described above. This is because the first temperature detection element 8 detects the outside temperature when the outside temperature is below a predetermined value, and as a result, the first temperature detection circuit 9 outputs an H signal to start defrosting, preventing so-called air defrosting. .

Therefore, if frost builds up on the outdoor heat exchanger and the temperature of the outdoor heat exchanger decreases before the accumulated operating time of the compressor reaches the predetermined value under high humidity outdoor air conditions, the time when the temperature is below the predetermined temperature is accumulated and the When the cumulative time reaches a predetermined value, defrosting occurs even if the compressor operating time does not reach the predetermined value, eliminating the conventional problem of delayed defrost timing and reduced heating capacity, which impairs the comfort of air conditioning. can do.

Effects of the Invention As described above, the present invention includes a first timer that integrates the operating time of the compressor, a first temperature detection circuit that detects the temperature of the outdoor heat exchanger that serves as the evaporator during heating, and the like. 7. A second timer that responds to the output of the first temperature detection circuit and integrates the duration when the temperature of the evaporator becomes below a predetermined temperature, a second temperature detection circuit that detects the outside air temperature, and the first timer. Defrosting is started when the cumulative time of the second timer reaches a predetermined value and the outside air temperature is above a predetermined value, other than when the cumulative time reaches a predetermined value and the temperature of the evaporator reaches a predetermined value or lower. Since the compressor is equipped with a means for defrosting, the speed of frost formation on the outdoor heat exchanger is fast under high humidity outside air conditions, and when the outdoor heat exchanger is frosted and needs to be defrosted, the accumulated operating time of the compressor is reduced to a predetermined value. Since defrosting is performed even before the defrost temperature reaches the desired temperature, defrosting is performed at the appropriate defrosting timing. Therefore, there is no problem that defrosting is delayed and the heating capacity is reduced as in the conventional case.

[Brief explanation of drawings]

Fig. 1 is a circuit block diagram of a control device for an air conditioner showing an embodiment of the present invention, Figs. 2 and 3 are wide chart diagrams showing the operation of the above control device, and Fig. 4 is a conventional air conditioner This is a diagram of the refrigeration system of the conditioner. 1... Compressor, 7... First timer, 9
...111th bench temperature detection circuit, 10...2nd timer, 14...
...Second temperature detection circuit. Name of agent: Patent attorney Toshio Nakao and 1 other person
2 Figure 3 Figure 4

Claims (1)

[Claims] a first timer for integrating the operating time of the compressor; a first temperature detection circuit for detecting the temperature of the evaporator; a second timer that integrates the duration; a second temperature detection circuit that detects the outside air temperature; A control device for an air conditioner, comprising means for starting defrosting of the evaporator when the cumulative time of two timers reaches a predetermined value and the outside air temperature is equal to or higher than a predetermined value.