JPH0493562A - Operation-controlling device for refrigeration arrangement - Google Patents

Abstract

PURPOSE:To improve the reliability of the title device by preventing unnecessary abnormal stoppage, by providing a means whereby a true signal for abnormally high pressure caused by closing of a stop valve or the like is discriminated from a signal for abnormally high pressure caused by the failure of a sensor. CONSTITUTION:During the operation of an air-conditioner, when a pressure on the side of high pressure is abnormally raised, the pressure is detected by an abnormally high pressure-detecting means HPS and a stopping signal is outputted. After the pressure on the side of high pressure is lowered by an abnormality-processing means 51, a reset process whereby the operation is restarted is repeated. During the resetting process, when the stopping signals above specified times are outputted, the air- conditioner is emergency-stopped, and hence the times of emergency stops caused by the failure of the abnormally high pressure-detecting means HPS are prevented from unnecessarily increasing. When the pressure on the side of high pressure is abnormally raised by closing of a stop valve, a stopping signal is received by a forcibly stopping means 52. After that, when the stop signal is released as soon as the pressure on the side of high pressure is lowered by the control of the abnormality-processing mean.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an operation control device for an air conditioner that uses a four-way switching valve to switch between cooling and heating cycles. Regarding failure prevention measures.

(Prior Art) Conventionally, as disclosed in, for example, Japanese Unexamined Patent Publication No. 1-147270, a refrigerant circuit including a compressor, a heat source side heat exchanger, a pressure reducing valve, and a user side heat exchanger are connected in sequence, In an air conditioner equipped with a four-way switching valve that reversibly switches the heating and cooling cycle of the refrigerant circuit, when the high pressure side pressure reaches a set value or higher, a high pressure abnormal signal (stop signal) is output and the operation of the air conditioner is stopped. It is a known technique to protect the air conditioner by stopping the air conditioner.

(Problem to be Solved by the Invention) By the way, when an air conditioner is brought to an abnormal stop due to an excessive rise in the pressure on the high pressure side, as in the conventional system described above, in order to prevent false detection, a - degree high pressure abnormal signal is used to stop the air conditioner. In some cases, a so-called retry function is provided, which does not stop the motor immediately, but waits for the abnormal stop until a high voltage abnormality signal is output several times. That is, a high pressure abnormality may also be caused by malfunction of a sensor, and especially immediately after the air conditioner is operated, the characteristics of the sensor are not stable, so malfunction may occur. Therefore, by providing such a try function, the number of abnormal stoppages can be reduced.

However, in the refrigerant circuit, if the shutoff valve is closed, for example, when an air conditioner is installed or repaired, the refrigerant will not circulate, and the high pressure will naturally rise excessively, causing a high pressure abnormality signal. However, in the case where a try function is provided as described above, high pressure is applied to the four-way selector valve many times. Then, as a result of the valve body of the four-way switching valve receiving such high pressure application many times, there is a problem that the four-way switching valve may malfunction.

The present invention has been made in view of the above, and its purpose is to provide a means for distinguishing between a true high-pressure abnormal signal caused by the closure of a closing valve, etc., and a high-pressure abnormal signal caused by a sensor abnormality. By doing so, while preventing unnecessary abnormal stoppages,
The purpose is to improve reliability.

(Means for Solving the Problem) In order to achieve the above object, the solving means of the present invention includes a compressor (1), a heat source side heat exchanger (3), a pressure reducing valve (5), as shown in FIG. The present invention assumes an air conditioner equipped with a refrigerant circuit (9) which is connected to a user-side heat exchanger (6) in sequence and is provided with a four-way switching valve (2) that switches the refrigerant circulation direction to a forward/reverse cycle. do.

As an operation control device for the air conditioner, the high pressure abnormality detection device detects the high pressure side pressure of the refrigerant circuit (9) during operation of the air conditioner and outputs a stop signal when the high pressure side pressure reaches an upper limit value or more. Upon receiving a stop signal from the high pressure abnormality detection means (HPS) and the high pressure abnormality detection means (HPS), a recovery process is performed to lower the high pressure side pressure and resume operation, and a predetermined number of times until a stop signal is received from another. When the abnormal stop signal is canceled immediately after receiving the stop signal from the abnormality processing means (51) that controls the air conditioner to abnormally stop when the above-mentioned high pressure abnormality detection means (HPS) is received, the above-mentioned This configuration includes a forced stop means (52) that forcibly stops the control of the abnormality processing means (5 units) to immediately bring the air conditioner to an abnormal stop.

(Function) With the above configuration, in the present invention, when the high pressure side pressure rises excessively during operation of the air conditioner, the high pressure abnormality detection means (H
PS) detects this and outputs a stop signal instructing the device to abnormally stop.

Then, in response to the stop signal, the abnormality processing means (51) repeatedly performs a return process of reducing the high pressure side pressure and restarting the operation, and if a stop signal is output a predetermined number of times or more during that time, the air conditioner Since the air conditioner is processed to abnormally stop, an abnormal stop of the air conditioner due to a failure of the high pressure abnormality detection means (HPS) is avoided, and an unnecessary increase in the number of abnormal stops is prevented.

In that case, when the high-pressure side pressure rises excessively due to closing of the shutoff valve, there is a risk that high pressure will act on the four-way switching valve (2) and cause failure of the valve body. After the forced stop means (52) receives a stop signal, when the high pressure side pressure decreases under the control of the abnormality processing means (51) and the stop signal is immediately canceled, the abnormality processing means (51) Since the air conditioner is controlled to be abnormally stopped by forcibly stopping the control, re-application of high pressure to the four-way switching valve (2) is prevented, and reliability is improved.

(Example) Hereinafter, an example of the present invention will be described based on the drawings from FIG. 2 onwards.

Fig. 2 shows the refrigerant piping system of an air conditioner to which the present invention is applied, in which (1) is the compressor, (2) is the four pipes that switch during cooling operation as shown by the solid line in the figure, and during heating operation as shown by the broken line in the figure. The road switching valve (3) functions as a condenser during cooling operation.
The outdoor heat exchanger is a heat source side heat exchanger that functions as an evaporator during heating operation, (4) is a receiver for storing liquid refrigerant, and (5) has a refrigerant pressure reduction function and a refrigerant flow rate adjustment function. The electric expansion valve (6) is an indoor heat exchanger that is installed indoors and functions as an evaporator during cooling operation and as a condenser during heating operation, and (7) is an indoor heat exchanger for the compressor (1). This is an accumulator installed in the suction pipe to remove liquid refrigerant from the suction refrigerant.

The above-mentioned devices (1) to (7) are sequentially connected by refrigerant piping (8) to form a refrigerant circuit (9) that causes heat transfer by circulating the refrigerant.

Here, an oil recovery device (10) for recovering oil in the discharged refrigerant is interposed on the discharge side of the compressor (1) of the refrigerant circuit (9), and the oil recovery device (10) Kara compressor (1)
- Oil skimmer (1) up to the suction pipe between the accumulator (7)
An oil return passage (11) is provided for returning the oil from the compressor (1) to the suction side of the compressor (1). The oil return passage (11) is provided with an on-off valve (12) that opens and closes the passage, and while the on-off valve (12) is normally closed, the oil return passage (11) is closed when the compressor (1) is started. At certain times, it is opened under predetermined control to return part of the oil and discharged refrigerant from the oil recovery device (10) to the suction side of the compressor (1).

Further, in the liquid pipe of the refrigerant circuit (9), the receiver (
4) and the electric expansion valve (5) are connected to a common path (8) so that the electric expansion valve (5) communicates with the lower part of the receiver (4), that is, the liquid part.
a), and the point (P) which is the upper end of the receiver (4) of the common path (8a) and the outdoor heat exchanger (
3) is connected to the first inflow path (8b
), there is a second check valve (22) between the point (P) of the common path (8a) and the indoor heat exchanger (6) that allows the refrigerant to flow only to the receiver (4) side. and the second inflow path (8
c) respectively, while the common path (8a
) between the point (Q) which is the end on the electric expansion valve (5) side and the point (S) between the first check valve (21) and the outdoor heat exchanger (3).
) is the connection between the point (Q) of the common path (8a) and the second check valve (22) - the indoor heat exchanger ( 6) The point between (
R) is the second capillary tube (C2).
They are connected to each other by a flow path (8e).

That is, during cooling operation, the liquid refrigerant condensed and liquefied in the outdoor heat exchanger (3) passes through the first check valve (21) and is stored in the receiver (4), and then flows through the electric expansion valve (5) and the second capillary. After being depressurized in the tube (C2), the indoor heat exchanger (6
) and return to the compressor (1), while during heating operation, the liquid refrigerant condensed and liquefied in the indoor heat exchanger (6) passes through the second check valve (22) and returns to the receiver (4). is stored in the electric expansion valve (5) and the first capillary tube (C
After being depressurized in step 1), the air is evaporated in an outdoor heat exchanger (3) and then returned to the compressor (1) for circulation.

Note that (14) and (14) are closing valves provided at the outlet end of the refrigerant pipe (8) to which the connecting pipe is attached in the outdoor unit. In addition, (8f) indicates the first check valve (2) in the first inflow path (8b) between point (P) and point (S).
1), and a third capillary tube (C3) for reducing the pressure of the refrigerant is interposed in the liquid seal prevention bypass path (8f).

Furthermore, sensors are arranged in the air conditioner; (Th2) is a discharge pipe sensor arranged in the discharge pipe of the compressor (1) and detects the discharge pipe temperature; (The he) is a discharge pipe sensor arranged in the discharge pipe of the compressor (1); The external heat exchange sensor is placed in the liquid pipe of the outdoor heat exchanger (3) and detects the condensation temperature of the refrigerant during cooling operation and the evaporation temperature of the refrigerant during heating operation. (T ha) is the air inlet of the outdoor heat exchanger (3). an outside temperature sensor located at the
(T he) is placed in the liquid pipe of the indoor heat exchanger (6),
The internal heat exchange sensor detects the evaporation temperature during cooling operation and the condensation temperature during heating operation. (Thr) is the indoor heat exchanger (6)
The indoor suction sensor is placed at the air suction port of the air conditioner and detects the suction air temperature Tr. , the controller controls the operation of each device according to the signals from the sensors.

In addition, (HPS) is a high-pressure pressure switch that serves as a high-pressure abnormality detection means, and the high-pressure pressure switch (HPS) detects when the high-pressure side pressure rises excessively and reaches the upper limit value. A stop signal is output that instructs the air conditioner to abnormally stop.

Here, the contents of the high voltage protection control by the above controller will be explained based on the flowchart in FIG.
In step S1, normal operation is performed until the high pressure switch (HPS) is activated, and when the high pressure switch (HPS) is activated and a stop signal instructing the air conditioner to abnormally stop is output. , the process proceeds to step S2 and the compressor (1) is stopped. And high pressure switch (HPS)
) After integrating the high pressure abnormality retry flag F (hps), which counts the number of times a stop signal is output from It is determined whether or not the stop signal of the high pressure pressure switch (HPS) has been released after the return, and if the high pressure switch (HPS) has not returned, the process proceeds to step S6, and it is determined whether the high pressure abnormality retry flag F hps is "3" or more. ,F
Until hps≧3, the process proceeds to step S7, where the thermostat is turned off, and then, in step S8, it is determined again whether the high pressure switch (HPS) has returned, and if it has returned, the above control is repeated. (The following control details are omitted).

On the other hand, if Fhps≧3 is determined in step S6, it is determined that the sensor is not abnormal, and the process moves to step S9, where the high pressure abnormality retry flag Fhps is reset, and then, in step SIO, the air conditioner is Perform abnormal processing to stop.

Here, as a feature of the present invention, if the high pressure switch (HPS) is restored in the determination in step S5, the process moves to step S9 regardless of the high pressure abnormality retry flag FhpsO value, and the step S9 and Controls sho.

In the above control flow, steps S2 to S6 and S
Under the control of the IO, upon receiving a stop signal from the high pressure switch (HPS), a recovery process is performed to lower the high pressure side pressure and resume operation, and the HPS receives a stop signal for a predetermined number of times or more before receiving a stop signal from another source. An abnormality processing means (51) is configured to control the air conditioner to abnormally stop at times,
According to the control that moves from step S5 to $10, after receiving a stop signal from the high pressure switch (HPS), when the stop signal is canceled immediately (after 1 second in the above embodiment), the abnormality processing means ( A forced stop means (52) is configured to forcibly stop the control of step 51) and immediately bring the air conditioner to an abnormal stop.

Therefore, in the above embodiment, when the air conditioner is operated,
If the high pressure side pressure rises excessively for some reason, this is detected by a high pressure switch (high pressure abnormality detection means) (HPS), and a stop signal is output that instructs the air conditioner to stop.

Then, in order to avoid abnormal stoppage due to malfunction of the high pressure switch (HPS), the abnormality processing means (51) receives this stop signal and performs a recovery process in which the compressor (1) is temporarily stopped and then restarted. is repeatedly performed, and when an abnormality signal is output a predetermined number of times (three times in the above embodiment) or more before receiving a stop signal from another, the abnormality stop means (51)
The air conditioner is controlled to abnormally stop.

In that case, the installation of the air conditioner will require a closing valve (14
), (14) is closed and the air conditioner is operated, the high pressure will rise rapidly, but even in this case, as in step S6 of the above embodiment, until the stop signal is output three or more times, If the abnormal stop is avoided, the valve body of the four-way switching valve (2) will be exposed to high pressure many times, and eventually the four-way switching valve (2) will be partially deformed due to the high pressure and the four-way switching valve (2) will not be able to switch. There is a risk that the valve (2) will malfunction.

In contrast, in the present invention, when the stop signal is released immediately after the high pressure switch (HPS) outputs the stop signal, the forced stop means (52) performs retry control by the abnormality processing means (51). The system is controlled to abnormally stop the air conditioner without doing so. In other words, if the stop signal is due to a failure of the high pressure switch (HPS), the stop signal will continue without being canceled;
If the pressure rises due to the closing of the shutoff valves (14), (14), etc., the compressor (2) can be stopped, etc.
The high pressure side pressure drops immediately and the stop signal is released. Therefore, by detecting the release of the stop signal, it is possible to distinguish between a stop signal due to a failure of the high-pressure switch (HPS) and a stop signal due to a change in the true refrigerant state. Failure of the switching valve (2) can be prevented.

In this case, if the stop signal continues, the abnormality processing means (51) performs retry control, so that the number of abnormal stops of the air conditioner is not increased unnecessarily.
Reliability can be improved.

(Effects of the Invention) As explained above, according to the present invention, as an operation control device for an air conditioner in which the refrigerant circulation cycle is switched between forward and reverse directions using a four-way switching valve, outputs a stop signal, and when this stop signal is output,
The recovery process of lowering the high-pressure side pressure and restarting operation is repeated, and when a stop signal is output a predetermined number of times before receiving a stop signal from another device, the air conditioner is abnormally stopped, and the stop signal is When the output is canceled immediately after the output, the air conditioner is forcibly brought to an abnormal stop, which prevents malfunctions caused by high pressure acting on the four-way selector valve many times. Reliability can be improved without causing an unnecessary increase in the number of abnormal stoppages of the harmonizing device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the present invention. 2 and 3 show an embodiment of the present invention, FIG. 2 is a refrigerant piping system diagram showing the configuration of an air conditioner, and FIG. 3 is a flowchart showing the details of high pressure protection control by the controller. 1 Compressor 2 Four-way switching valve 3 Outdoor heat exchanger (heat source side heat exchanger) 5 Electric expansion valve (pressure reducing valve) 6 Indoor heat exchanger (user side heat exchanger) 51 Abnormality processing means 52 Forced stop means HPS High pressure Pressure switch (high pressure abnormality detection means) Section 3

Claims (1)

[Claims] (1) Compressor (1), heat source side heat exchanger (3), pressure reducing valve (
5) and the user-side heat exchanger (6) in sequence, and a four-way switching valve (2) that switches the refrigerant circulation direction to a forward/reverse cycle.
In an air conditioner equipped with a refrigerant circuit (9), the high pressure side pressure of the refrigerant circuit (9) is detected during operation of the air conditioner, and when the high pressure side pressure reaches an upper limit value or more, a stop signal is issued. When receiving a stop signal from the high pressure abnormality detection means (HPS) and the high pressure abnormality detection means (HPS) that outputs the
An abnormality processing means (51) that performs a recovery process of reducing the high pressure side pressure and restarting operation, and also controls the air conditioner to abnormally stop when a stop signal is received from another device for a predetermined number of times or more. and when the abnormal stop signal is canceled immediately after receiving the stop signal from the high pressure abnormality detection means (HPS), the abnormality processing means (51)
An operation control device for an air conditioner, comprising a forced stop means (52) for forcibly stopping the control of the air conditioner so as to immediately bring the air conditioner to an abnormal stop.