JPH0455671A - Refrigerating cycle device - Google Patents

Abstract

PURPOSE:To improve gas leak detecting accuracy by a method wherein a gas leak detecting means detects that the detected value of refrigerant discharging temperature has exceeded a set value while a conducted current to a compressor, which is detected by a current sensor, has reduced to a value lower than a set value. CONSTITUTION:A gas leak detecting means 12 reads a refrigerant discharging temperature detecting value (td) from a discharging temperature sensor 7 during the operation of a compressor 2 and compares it with a set value T. When the condition of td>T has been established, the gas leak detecting means 12 reads further a conducted current (ic) for a compressor 2 from a current sensor 11 and when the condition of ic<I (here I is a set value) is established, the detecting means 12 puts a switch 10 OFF to intercept the conduction of the current to the compressor 2 and stop the operation of the same. When a refrigerant discharging temperature value (td), detected by the discharging temperature sensor 7, has exceeded the set value T due to the overload operation of the compressor 2, the compressor 2 is operated with an overload and, therefore, the current value (ic), detected by the current sensor 11, is not reduced than the set value I. Accordingly, only the generation of gas leak can be detected correctly.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a refrigeration cycle device such as an air conditioner or a refrigeration device, and particularly relates to a gas leak detection means for detecting a leak of refrigerant gas. This invention relates to an improved refrigeration cycle device.

(Prior Art) Conventionally, this type of refrigeration cycle device has a compressor, a condenser, a throttle device, and an evaporator connected sequentially and in an annular manner through refrigerant piping to form a closed refrigeration cycle in which refrigerant is circulated. A gas leak detection means is provided to detect leakage of refrigerant gas from the cycle.

This gas leak detection means 8 detects when a gas leak occurs when the discharge temperature td of the refrigerant gas detected by the discharge temperature sensor installed on the discharge side piping of the compressor exceeds the set value T as shown in the flowchart of Fig. 3. It is determined that this is the case, and the on/off contact that controls the energization to the compressor is opened to cut off the energization to the compressor and stop its operation.

(Problem to be Solved by the Invention) However, with such conventional gas leak detection means, even when no refrigerant gas leak occurs, if the refrigerant discharge temperature [d exceeds the set value T] due to overload of the refrigeration cycle, There is a problem in that the system incorrectly determines that a gas leak has occurred, causing the compressor to stop operating and reducing its operating rate.

Therefore, the present invention has been made in consideration of the above circumstances, and an object thereof is to provide a refrigeration cycle device that can improve the accuracy of gas leak detection.

[Structure of the invention]

(Means for Solving the Problems) The present invention has been made by focusing on the fact that the current flowing to the compressor increases during overload operation, but decreases due to a light load when there is a gas leak. It is composed of

In other words, the present invention provides a refrigeration cycle device that constitutes a closed refrigeration cycle in which a compressor, a condenser, a throttle device, and an evaporator are sequentially connected by refrigerant piping to circulate refrigerant, and in which a discharge temperature is detected to detect the temperature of the refrigerant discharged from the compressor. a temperature sensor; a current sensor that detects the current flowing to the compressor; and a current sensor that detects the current flowing to the compressor; The invention is characterized in that it is provided with a gas leak detection means for cutting off energization.

(Function) When refrigerant gas leaks from the refrigeration cycle, the circulation flow rate of refrigerant circulating through this refrigeration cycle is reduced, so the discharge temperature of the refrigerant gas discharged from the compressor increases, and the load on the compressor becomes light. , the current flowing to the compressor decreases.

For this reason, when the gas leak detection means detects that the refrigerant discharge temperature detected by the discharge temperature sensor exceeds the set value and the current flowing to the compressor detected by the current sensor has fallen below the set value, this Electricity to the compressor is cut off by the gas leak detection means 8, and the operation of the compressor is stopped.

However, even if the refrigerant gas discharge temperature detected by the discharge temperature sensor exceeds the set value during simple overload operation without any refrigerant gas leakage, the compressor will be operated under overload. The current applied to the current does not decrease, but rather increases.

Therefore, even if the temperature detected by the discharge temperature sensor exceeds the set value, the current detected by the current sensor does not fall below the set value, so the gas leak detection means continues to supply electricity to the compressor without determining whether a gas leak has occurred. and continue its operation.

Therefore, according to the present invention, it is possible to prevent the occurrence of a gas leak from being erroneously determined during overload operation of the compressor, and to accurately detect a gas leak.

(Example) An example of the present invention will be described below based on FIGS. 1 and 2.

FIG. 1 is a diagram of a refrigeration cycle according to an embodiment of the present invention. In the figure, a refrigeration cycle device 1 includes a compressor 2, a condenser 3, an expansion valve 4 serving as a throttle device, and an evaporator 5, which are connected in this order through a refrigerant pipe 6. connected in a ring,
It constitutes a closed refrigeration cycle in which refrigerant circulates in the direction of the arrow in the figure.

The compressor 2 is provided with a discharge temperature sensor 7 for detecting the temperature of the refrigerant gas discharged in the discharge pipe 6a that discharges the compressed refrigerant gas, and a discharge temperature sensor 7 for detecting the temperature of the refrigerant gas discharged from the discharge pipe 6a, which is connected to the current-carrying path 9 that electrically connects the compressor 2 to the power source 8. A normally closed switch 10 and a current sensor 11 for detecting the current flowing to the compressor 2 are interposed in the middle.

The current sensor 11 and the discharge temperature sensor 7 are electrically connected to the gas leak detection means 12, and when the refrigerant discharge temperature from the compressor 2 detected by the discharge temperature sensor 7 exceeds a set value, and the current sensor When the current flowing to the compressor 2 detected by 11 falls below the set value, the occurrence of a refrigerant gas leak is detected, and the switch 10 is turned OFF.
F, and the compressor 2 is de-energized to stop its operation, and has a program shown in FIG.

That is, as shown in FIG. 2, the gas leak detection means 12 reads the refrigerant discharge temperature detection value td from the discharge temperature sensor 7 during the operation of the compressor 2, compares this with the set value T, and calculates the discharge a temperature detection value td. >Determine whether or not the set value T holds true.

If this is YES, that is, if td>T holds true, then read the energizing current ic from the current sensor 9 to the compressor 2, compare it with the set value I, and open/close when the detected current ic < set value I holds true. The compressor 10 is controlled to turn off, the power supply to the compressor 2 is cut off, and its operation is stopped.

Therefore, according to this embodiment, even if the refrigerant discharge temperature detection value td detected by the discharge temperature sensor 7 exceeds the set value T due to overload operation of the compressor 2, in this case, the compressor 2 is overloaded. Since the current flowing from the power supply 8 to the compressor 2 increases but never decreases, the current detection value ic detected by the current sensor 11 does not fall below the set value.

For this purpose, the gas leak detection means 12
It is possible to accurately detect only the occurrence of a gas leak without detecting the occurrence of a gas leak during overload operation.

For this reason, when the compressor 2 is operated under an overload, the operation of the compressor 2 can be stopped and its operating rate can be prevented from decreasing.

〔Effect of the invention〕

As explained above, in the present invention, when it is detected that the refrigerant discharge temperature detected value from the discharge temperature sensor exceeds the set value and the energization current detected value from the current sensor is lower than the set value, the refrigerant gas We have installed a gas leak detection means that detects the occurrence of a leak and cuts off the power to the compressor.
It is possible to prevent the occurrence of gas leaks from being erroneously detected when the compressor is overloaded, resulting in high gas leak detection accuracy.

[Brief explanation of the drawing]

Fig. 1 is an overall configuration diagram of an embodiment of a refrigeration cycle device according to the present invention, Fig. 2 is a flowchart of a control program for the gas leak detection means shown in Fig. 1, and Fig. 3 shows the operation of the conventional gas leak detection means. It is a flowchart explaining. 1... Refrigeration cycle device, 2... Compressor, 3
... Capacitor, 4... Expansion valve (throttle device), 5.
Evaporator, 6... Refrigerant piping, 7... Discharge temperature sensor, 11... Current sensor, 12... Gas leak detection means. Applicant's agent Hisashi Hatano Figure 2 Figure 31! l

Claims (1)

[Claims] In a refrigeration cycle device that constitutes a closed refrigeration cycle in which a compressor, a condenser, a throttle device, and an evaporator are sequentially connected by refrigerant piping to circulate refrigerant, a discharge temperature sensor that detects the discharge temperature of refrigerant from the compressor; a current sensor that detects the current flowing to the compressor; and a gas leak that cuts off the current flow to the compressor when the temperature detected by the discharge temperature sensor exceeds a set value and the detected current from the current sensor falls below the set value. A refrigeration cycle device comprising: a detection means.