JPH05126443A - Controller of refrigerator - Google Patents

Abstract

PURPOSE:To obtain a controller for a refrigerating machine, which is capable of accurately detecting the abnormal state of a temperature sensor when the temperature sensor fails to play the role as a sensor. CONSTITUTION:A temperature detector 15 detects temperature before or immediately after a compressor 4 is started and the detector 15 detects also temperature when a specified time has elapsed after the compressor 4 is started, and the temperature difference is calculated. When the temperature difference is a specified value or less, a controller 13 indicates the fact that the compressor 4 is in an abnormal state, or stops the compressor 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerator controller for detecting a refrigerant temperature with a temperature sensor and controlling the operation of a compressor in accordance with a value detected by the sensor.

[0002]

2. Description of the Related Art Generally, a technique is known in which a temperature sensor is provided in a refrigeration cycle to detect the temperature of each part to control a motor-operated valve, or to detect an abnormal operation to protect a unit. (For example, JP-A-62-7
3058 publication).

In this type, when the temperature detected by the temperature sensor becomes abnormally high, it is determined that the refrigerant gas in the refrigeration cycle is insufficient, and the operation of the compressor is stopped. ing.

[0004]

However, the sensor for detecting the temperature of the refrigerant provided in the refrigeration cycle is usually used by being brought into close contact with the measurement point. However, there is a problem in that the compressor cannot be controlled normally and the compressor cannot be normally controlled. For example, when replacing the compressor, if a sensor is attached to the compressor, remove this sensor from the compressor, replace it with a new compressor, and then install the sensor again. If the sensor is forgotten to be attached, there is a problem that the compressor cannot be normally controlled thereafter.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, and when the temperature sensor can no longer serve as a sensor, it is possible to accurately detect the abnormal state. To provide a control device for the machine.

[0006]

In order to achieve the above object, the present invention constitutes a refrigeration cycle by connecting a compressor, a condenser, a pressure reducer, an evaporator and the like with a refrigerant pipe, and Provided with a temperature sensor for detecting the temperature of the refrigerant flowing through, in the controller of the refrigerator configured to control the operation of the compressor based on the value detected by this temperature sensor, before or immediately after the start of operation of the compressor. When the difference between the value detected by the temperature sensor and the value detected by the temperature sensor after a lapse of a certain time from the start of operation of the compressor is less than or equal to a predetermined value, an abnormality display of the operation of the compressor and / or a command to stop the operation of the compressor It is characterized in that it is provided with a control means for controlling.

[0007]

According to the present invention, as long as the temperature sensor is functioning normally, the refrigerant temperature should reach the predetermined temperature after the lapse of a predetermined time after the start of operation of the compressor. Based on this, the difference between the value detected by the temperature sensor before or immediately after the start of operation of the compressor and the value detected by the temperature sensor after a lapse of a certain time from the start of operation is calculated, and this difference is compared with a predetermined temperature difference. Then, when it is smaller than the predetermined temperature difference, it is determined to be abnormal (the temperature sensor is not functioning normally), so that it is possible to reliably detect the detachment of the temperature sensor from the outer case of the compressor, for example. ..

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, 1 is a separation type air conditioner, and this air conditioner 1 is composed of an indoor unit A, an outdoor unit B, and an inter-unit pipe 2 connecting both units. The indoor unit A has a built-in indoor heat exchanger 3 that acts as an evaporator during cooling operation and as a condenser during heating operation, and the outdoor unit B has a scroll compressor 4, a four-way valve 5, and during cooling operation. An outdoor heat exchanger 6 that acts as a condenser and an evaporator during heating operation
And an accumulator 7 are built in.

Reference numeral 9 denotes an electric valve, and the electric valve 9 has an initial opening setting means 1 for setting an initial opening of the electric valve 9.
1 is connected. The initial opening degree setting means 11 operates for about 8 minutes from the start of operation, and outputs about 250 pulses to the motor-operated valve 9 when the outside air temperature is cold such as 10 ° C. or less during heating operation. In addition to setting the opening degree of the motor-operated valve 9, when the outside air temperature is about 10 to 20 ° C., about 300 pulses are output and the opening degree of the motor-operated valve 9 is set to be larger than that when the outside temperature is 10 ° C. or less. Is 20 ° C. or higher, it outputs about 350 pulses to further increase the opening degree of the motor-operated valve 9. Here, when the motor-operated valve 9 is fully opened, the initial opening degree setting means 11 outputs about 480 pulses.

A control means 13 for controlling the apparatus of this embodiment is connected to the electric valve 9, and a temperature sensor 15 for detecting the temperature of the refrigerant inside the compressor 4 is connected to the control means 13. ing. As shown in FIG. 2, the temperature sensor 15 is attached to the exterior case 4a of the scroll compressor 4. The temperature sensor 15 itself is housed in a sensor case 15a, and a sensor retainer 17 is attached to the sensor case 15a so as to press the lead wire 15b of the temperature sensor 15. 19
Is a discharge pipe.

Next, the operation of the embodiment will be described.

When the four-way valve 5 is switched to change the flow of the refrigerant, the cooling operation or the heating operation is performed. In FIG. 1, the flow of the refrigerant during cooling is indicated by a solid line, and the flow of the refrigerant during heating is indicated by a dotted line.

By the way, during operation, the scroll compressor 4
If the temperature of the compressor becomes abnormally high, for example, the refrigerant gas in the refrigeration cycle may be insufficient. In such a case, it is indicated by a lamp that the compressor 4 is abnormal. Or the compressor 4 must be stopped.

However, according to this embodiment, the temperature sensor 15 detects the temperature of the refrigerant, and the detected value indicating the temperature of the refrigerant is sent to the control device 13, where the compressor 4 follows the flowchart shown in FIG. Is controlled and
The valve opening degree of the motor-operated valve 9 is controlled to be an appropriate opening degree.

Referring to FIG. 3, when the power source is turned on (step 1), the temperature sensor 15 first detects the refrigerant temperature T ₀ before the compressor 4 starts operating (step 2), and thereafter,
The operation of the compressor 4 is started (step 3). At this stage, the valve opening degree of the motor-operated valve 9 is controlled by the initial opening degree setting means 11.

Next, it is judged whether or not 120 seconds have elapsed after the start of operation (step 4), and if not elapsed, the process returns to step 4, and if so, the refrigerant temperature T ₁ at that time is the temperature. The absolute value of the difference T ₀ −T ₁ between the refrigerant temperature T ₀ before the start of operation detected by the sensor 15 and the refrigerant temperature T ₁ detected here is obtained, and this difference | T ₀ −T ₁ | is compared with a preset temperature difference α (step 5). If the difference | T ₀ −T ₁ | is larger than the predetermined temperature difference α, it is judged to be normal (step 6), and thereafter, the compressor 4 based on the difference between the indoor temperature and the set temperature is detected. Control shifts to normal control (step 7), and correspondingly, the valve opening of the motor-operated valve 9 is controlled to an appropriate opening.

However, when the difference | T ₀ −T ₁ | is smaller than the predetermined temperature difference α, this is abnormal (temperature sensor 1
5 is not functioning normally) (step 8), the operation of the compressor 4 is stopped (step 9). In step 9, the lamp may be used to indicate that the compressor 4 is abnormal.

That is, in this embodiment, as long as the temperature sensor 15 is functioning normally, the temperature of the refrigerant must be maintained after a predetermined time (120 seconds in this embodiment) has elapsed after the start of the operation of the compressor 4. It is noted that the difference | T ₀ −T ₁ |
_0- T ₁ | is compared with a predetermined temperature difference α, and when it is smaller than the temperature difference α, it is determined that an abnormality has occurred (the temperature sensor 15 is not functioning normally). Trouble such as the temperature sensor 15 coming off (disengaging) from the outer case 4a can be reliably detected.

In this embodiment, the temperature sensor 15 is attached to the exterior case 4a of the compressor 4. However, as another example, the temperature sensor 15 is attached to the discharge pipe 19 of the compressor 4 or indoors / outdoors. It is possible to apply to the thing attached to the heat exchangers 3 and 6.

FIG. 4 shows another embodiment. In this example, the outdoor units A ₁ , A ₂ , A ₃ and the indoor unit B ₁ which form the separation type air conditioners 1 ₁ , 1 ₂ , 1 _3. , B ₂ ,
A plurality of B ₃ are installed.

When the units are brought close to each other in this manner, there is a risk of incorrect wiring when electrically wiring. In the figure, thick lines indicate inter-unit wiring 2 ₁ , 2 ₂ , 2 ₃ , thin lines indicate normal electrical wiring, and dotted lines indicate so-called erroneous wiring. When this miswiring is performed, there arises a problem in durability of the compressor, and there is a problem in that the discovery of the miswiring is delayed until a known protection device against the miswiring is activated.

However, in this embodiment, a temperature sensor (not shown) for detecting the refrigerant temperature is provided during the refrigeration cycle of each separation type air conditioner, and a so-called temperature sensor based on the temperature information from this temperature sensor is used. Incorrect wiring is detected.

Referring to FIG. 5, after the power is turned on (step 11), first the temperature sensor detects the refrigerant temperature T ₀ during the refrigeration cycle (step 12).
Next, the operation of the compressor is started (step 13).
After the start of the operation, the refrigerant temperature T ₁ in the refrigeration cycle is detected again (step 14), and the absolute value | T ₀ −T ₁ | of the difference between the temperature T ₁ and the refrigerant temperature T ₀ is obtained, This difference | T ₀ −T ₁ | is compared with a preset predetermined temperature difference β, and if it is larger than this temperature difference β, the operation is continued (step 15).

On the other hand, the difference | T ₀ −T ₁ | is the temperature difference β.
If it is smaller than the above, it is judged that there is miswiring and an alarm is issued (step 16), and then the operation of the compressor is stopped (step 17).

That is, according to this embodiment, it is noted that the refrigerant temperature does not rise because the compressor to be controlled is not operated in the case of incorrect wiring. , The difference | T ₀ −T ₁ |
_{Since 0-} T ₁ | is compared with a predetermined temperature difference β and an alarm is issued when this is smaller than the temperature difference β, so-called miswiring can be reliably detected. Note that the value of the predetermined temperature β may be changed between during cooling and during heating, or the control according to this embodiment may be provided only under test operation.

[0027]

As is apparent from the above description, according to the present invention, the value detected by the temperature sensor before or immediately after the start of operation of the compressor and the temperature sensor after a lapse of a certain time from the start of operation of the compressor. When the difference from the value detected in is less than the predetermined value, the temperature sensor is not functioning normally because it is equipped with control means such as an abnormal display of the compressor operation or a command to stop the operation of the compressor. In such a case, erroneous wiring on the electrical wiring that occurs when a plurality of outdoor units and indoor units are installed can be reliably detected.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a control device for a refrigerator according to the present invention.

FIG. 2 is a cross-sectional view showing a part of a compressor which constitutes the refrigerating apparatus shown in FIG.

FIG. 3 is a flowchart showing an embodiment of a refrigerator control device according to the present invention.

FIG. 4 is an electrical wiring diagram showing another embodiment.

FIG. 5 is a flowchart of another embodiment of the present invention.

[Explanation of symbols]

 1 Separation type air conditioner 2 Piping between units 3 Indoor heat exchanger 4 Scroll type compressor 5 Four-way valve 6 Outdoor heat exchanger 9 Motorized valve 11 Initial opening setting means 13 Control means 15 Temperature sensor 19 Discharge pipe A Indoor unit B Outdoor unit

Claims (1)

[Claims] 1. A refrigeration cycle is constructed by connecting a compressor, a condenser, a decompressor, an evaporator, etc. with a refrigerant pipe, and a temperature sensor for detecting the temperature of a refrigerant flowing in the refrigeration cycle is provided. In the control device of the refrigerator configured to control the operation of the compressor based on the value detected by, from the operation start of the compressor and the value detected by the temperature sensor before or immediately after the start of operation of the compressor. When a difference from a value detected by the temperature sensor after a lapse of a certain time is less than or equal to a predetermined value, a control means for instructing to display an abnormal operation of the compressor and / or stop the operation of the compressor is provided. Refrigerator control device.