JPH09159293A - Compressor protection controller for air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect a compressor upon failure of a freezing cycle such as degassing of a much volume of refrigerant gas by interrupting the compressor when indoor heat exchange inlet piping temperature has becomes a set temperature or lower during heating operation. SOLUTION: This controller is provided with indoor temperature detection means 10 for detecting room temperature upon heating operation of an air conditioner, heat exchanger inlet piping temperature detection means 11 for detecting temperature of an inlet piping of an indoor side heat exchanger, temperature difference detection means 12 for detecting a temperature difference between heat exchanger inlet piping temperature and indoor temperature, temperature difference comparator means 13 for detecting and outputting a fact that the temperature difference is smaller than a set temperature difference, and compressor interruption means 14 for interrupting the compressor when a boundary value lowering signal by the temperature difference comparator means 13 succeeds continuously for the set time, and compressor operation frequency is more than the set frequency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner, and in an air conditioner equipped with a microcomputer, protects the compressor from heating operation, refrigerant gas outflow from the refrigeration cycle, and overload operation. The present invention relates to a control device that operates.

[0002]

2. Description of the Related Art Conventionally, in an air conditioner, in order to protect the compressor, an overload relay that reacts to temperature or operating radio waves is added to the surface of the compressor, and the surface temperature of the compressor or the operating current has a certain value. When it exceeds, the compressor was stopped.

FIG. 8 is a refrigeration cycle diagram in a conventional heat pump type air conditioner. As shown in the figure, 1 is a compressor, 2 is a four-way valve, 3 is an outdoor heat exchanger, 4 is an outdoor fan, 5 is a pressure reducer, 6 is an indoor heat exchanger, 7 is an indoor fan, 8 Is an overload relay that operates at the operating current and temperature of the compressor.

[0004]

However, the air conditioner configured as described above has the following problems. That is, when the air conditioner is operated under a high load condition or when the refrigerant is removed from the refrigeration cycle, the discharge temperature and the motor coil temperature in the compressor generally increase. Since the conventional device detects only the temperature of the compressor surface, it operates in an abnormal state (for example, when the air conditioner is installed, the condition close to the vacuum operation of the compressor due to forgetting to open the 2-way valve or a large amount of refrigerant leakage). In some cases, the compressor could not be completely protected from burnout. In addition, the discharge temperature may increase and the operating current value may decrease when the refrigerant gas escapes. For this reason, the conventional protection means can only support protection under some driving conditions.

The present invention has been made to solve the above problems, and an object of the present invention is to improve the accuracy of compressor protection by adding control on the indoor side.

[0006]

In order to solve the above problems, an air conditioner of the present invention is a refrigeration cycle equipped with a compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger. During the heating operation, the indoor temperature detecting means for detecting the indoor temperature and the heat exchange inlet pipe temperature detecting means for detecting the temperature of the inlet pipe of the indoor heat exchanger, and the heat exchange detected by the heat exchange inlet pipe temperature detecting means. A temperature difference detecting means for detecting a difference between the inlet pipe temperature and the room temperature detected by the room temperature detecting means, and a temperature difference detected by the temperature difference detecting means is stored in the set temperature difference storing means in advance. A temperature difference comparison means for detecting and outputting that the difference is smaller than the difference is provided, and the temperature difference decrease signal by the temperature difference comparison means
A compressor stopping means for stopping the compressor is provided.

Further, during heating operation of the air conditioner, operating time measuring means for measuring the time from the start of compressor operation, and operating time comparison for comparing the operating time with a preset time stored in the preset time storage means. Means for detecting whether or not the compressor is continuously operating for the set time after the set time has elapsed from the start of the compressor operation, and the temperature difference lowering signal by the temperature difference comparison means. Is provided with a continuous output detecting means for detecting and outputting the continuous output for a set time or more, and a compressor stopping means for stopping the compressor by the compressor continuous operation detecting means and the continuous output detecting means. Is.

Further, the compressor operating frequency control means for varying the compressor operating frequency, the compressor operating frequency detecting means for detecting the compressor operating frequency, and the compressor operating frequency detected by the compressor operating frequency detecting means are stored in the set frequency. A compressor for stopping the compressor by providing a frequency comparison means for detecting and outputting a frequency that is equal to or higher than a preset frequency stored in advance in the means, and detecting that a signal equal to or higher than the frequency boundary value is output by the frequency comparison means. It is provided with a stopping means.

Further, the compressor operating frequency control means for changing the compressor operating frequency, the compressor operating frequency detecting means for detecting the compressor operating frequency, and the compressor operating frequency detected by the compressor operating frequency detecting means are stored in the set frequency. The means is provided with a frequency comparison means for detecting and outputting that the frequency is equal to or higher than a preset frequency stored in advance, and it is detected by the frequency comparison means that a signal equal to or higher than the frequency boundary value is continuously output for a preset time or longer, and then output. The frequency continuous output detecting means is provided, and the frequency continuous output detecting means, the compressor continuous operation detecting means, and the compressor stopping means for stopping the compressor by the continuous output detecting means are provided.

[0010]

The operation of the above means is as follows.

That is, in a refrigeration cycle equipped with a compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger, an indoor temperature detecting means for detecting an indoor temperature and an indoor heat exchanger during heating operation. Heat exchanger inlet pipe temperature detecting means for detecting the temperature of the inlet pipe of the, and the difference between the heat exchanger inlet pipe temperature detected by the heat exchanger inlet pipe temperature detecting means and the room temperature detected by the room temperature detecting means The temperature difference detecting means and the temperature difference comparing means for detecting and outputting that the temperature difference detected by the temperature difference detecting means is smaller than the preset temperature difference stored in advance in the preset temperature difference storing means are provided. By the temperature difference lowering signal by the comparison means,
By having a compressor stopping means for stopping the compressor,
Pay attention to the fact that the inlet pipe temperature of the indoor heat exchanger does not rise when the refrigerant gas circulation amount is small, and the compressor is stopped when the temperature difference between the heat exchanger inlet pipe temperature and the indoor temperature is less than the set temperature difference. Then, the protection of the compressor is judged and controlled on the indoor side.

Further, during heating operation of the air conditioner, operating time measuring means for calculating the time from the start of compressor operation, and operating time comparison for comparing the operating time with the preset time stored in the preset time storage means. Means for detecting whether or not the compressor is continuously operating for the set time after the set time has elapsed from the start of the compressor operation, and the temperature difference lowering signal by the temperature difference comparison means. Is continuously output for a set time or longer, is provided with a continuous output detecting means for outputting, by having a compressor continuous operation detecting means and a compressor stopping means for stopping the compressor by the continuous output detecting means, Since the temperature difference between the heat exchange inlet pipe temperature and the room temperature is lower than the set temperature difference continuously for the set time,
The compressor is protected by a reliable judgment, not a judgment of an unstable state at the start-up or transition.

Further, the compressor operating frequency control means for changing the compressor operating frequency, the compressor operating frequency detecting means for detecting the compressor operating frequency, and the compressor operating frequency detected by the compressor operating frequency detecting means are stored in the set frequency. A compressor for stopping the compressor by providing a frequency comparison means for detecting and outputting a frequency that is equal to or higher than a preset frequency stored in advance in the means, and detecting that a signal equal to or higher than the frequency boundary value is output by the frequency comparison means. Even in an air conditioner that has a compressor operating frequency control means by having a stopping means, there is a small temperature difference between the heat exchange inlet pipe temperature and the room temperature even during normal operation at a low frequency, so there is less than the set frequency. It is possible to make a reliable protection judgment by limiting the operation to the above.

Further, the compressor operating frequency control means for changing the compressor operating frequency, the compressor operating frequency detecting means for detecting the compressor operating frequency, and the compressor operating frequency detected by the compressor operating frequency detecting means are stored in the set frequency. The means is provided with a frequency comparison means for detecting and outputting that the frequency is equal to or higher than a preset frequency stored in advance, and it is detected by the frequency comparison means that a signal equal to or higher than the frequency boundary value is continuously output for a preset time or longer, and then output. Air having the compressor operating frequency control means by providing the frequency continuous output detecting means, the compressor continuous operation detecting means, the compressor continuous operation detecting means, and the compressor stopping means for stopping the compressor by the continuous output detecting means. There is little temperature difference between the heat exchanger inlet pipe temperature and the room temperature even in the conditioner when operating at a low frequency even during normal operation. Because those capable of reliable protection determination by limiting the operation of a continuous set frequency above and set time.

[0015]

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

FIG. 5 shows a refrigerating cycle of the air conditioner in one embodiment of the present invention. As shown in the figure, 1 is a compressor, 2 is a four-way valve, 3 is an outdoor heat exchanger, 4 is an outdoor fan, 5 is a decompressor, 6 is an indoor heat exchanger, 7 is an indoor fan, 10 Is an indoor temperature detecting means (for example, a suction sensor) for detecting an indoor temperature, 11 is a heat exchange inlet pipe temperature detecting means for detecting a heat exchange inlet pipe temperature of the indoor heat side exchanger 6 (for example, a heat exchange inlet pipe temperature sensor) ).

In this refrigeration cycle, during the heating operation, the refrigerant discharged from the compressor 1 flows through the four-way valve 2, the indoor heat exchanger 6, the decompressor 5 and the outdoor heat exchanger 3, and the compressor 1
Inhaled.

The operation of the control circuit according to the present invention will be described below with reference to FIG. FIG. 1 is a schematic block diagram of an air conditioner according to a first embodiment of the present invention. In FIG. 1, 10 is an indoor temperature detecting means for detecting an indoor temperature (for example, a suction sensor), 11 is a heat exchange inlet pipe temperature detecting means for detecting a temperature of an inlet pipe of an indoor heat exchanger (for example, a heat exchange inlet pipe). Temperature sensor), 12
Is the heat exchanger inlet pipe temperature (Th) detected by the heat exchanger inlet pipe temperature detector 11 and the indoor temperature detector 10
The temperature difference detecting means for detecting the difference in the indoor temperature (Ti) detected by the reference numeral 13, and the setting 13 in which the temperature difference (T) detected by the temperature difference detecting means 12 is stored in the set temperature difference storage means 14 in advance. The compressor stop means 15 is provided with a temperature difference comparison means for detecting and outputting that the temperature difference is smaller than the temperature difference (T1), and the temperature difference decrease signal from the temperature difference comparison means 13 stops the compressor.

FIG. 6 is a flow chart of this control flow. First, the heat exchange inlet pipe temperature Th and the room temperature Ti are detected (101). And heat exchange inlet pipe temperature T
It is determined whether the value of the temperature difference T between h and the room temperature Ti is lower than the set temperature T1 (for example, T1 = 5 ° C.) (102),
If the condition is not satisfied, the process returns to 101, and if the condition is satisfied, the compressor is immediately stopped (103) and the compressor is protected. By this control, it is possible to avoid a refrigeration cycle failure due to a large amount of refrigerant gas escape, etc., only on the indoor side.
In addition, although the above-mentioned embodiment explained the separate type air conditioner, the same effect can be expected in the integrated type air conditioner. Further, since the temperature of the heat exchange inlet pipe connected to the refrigerant inlet side of the indoor heat exchanger is the refrigerant superheated gas temperature, stable determination can be performed without being affected by the indoor air volume and the like.

Next, a second embodiment of the present invention will be described. FIG. 2 is a schematic block diagram of an air conditioner according to the second embodiment of the present invention. In FIG. 2, 21 is a driving time measuring means for measuring the time from the start of driving, and 22 is a set time (t
1) storage means, 23 is an operation time comparison means for comparing the operation time and a set time (t1) stored in advance in the storage time (t1) storage means, and 24 is compressed after the set time has elapsed from the start of compressor operation. The compressor continuous operation detecting means for detecting whether or not the compressor is continuously operating for a set time, 25 detects that the boundary value lowering signal by the temperature difference comparing means 13 is continuously output for a set time or more. , Continuous output detecting means for outputting.

FIG. 7 is a flow chart of this control flow. First, the heat exchange inlet pipe temperature Th and the room temperature Ti are detected (201), and the heat exchanger inlet pipe temperature Th is detected.
It is determined whether the value of the temperature difference T between the room temperature Ti and the room temperature Ti is lower than the set temperature T1 (202). If the condition is not satisfied, the process returns to 201, and if the condition is satisfied, the time t from the start of the compressor operation is set. It is measured (203), and the compressor operating time t is compared with the set time t1 (for example, t1 = 5 minutes) (204),
After the set time t1 has elapsed, it is determined whether the compressor is continuously operating for the set time t1 (205). If the condition is not satisfied, the measured time t is cleared.
Returning to 1, the compressor is immediately stopped (206) if it is continuously operated for the set time t1, and the compressor is protected. By this control, it is possible to reliably avoid a refrigeration cycle failure due to a large amount of refrigerant gas escape, etc., only on the indoor side.

Next, a third embodiment of the present invention will be described. FIG. 3 is a schematic block diagram of an air conditioner according to a third embodiment of the present invention. In FIG. 3, 31 is a compressor operating frequency control means capable of varying the compressor operating frequency (f), 32
Is a compressor operating frequency detecting means for detecting the compressor operating frequency (f), and 33 is a set frequency (f) in which the compressor operating frequency (f) detected by the compressor operating frequency detecting means is stored in advance in the set frequency storing means. It is a frequency comparison means for detecting and outputting that it is equal to or more than fa).

FIG. 8 is a flow chart of this control flow. First, the heat exchange inlet pipe temperature Th and the room temperature Ti are detected (301), and the heat exchange inlet pipe temperature Th is detected.
It is determined whether the value of the temperature difference T between the room temperature Ti and the room temperature Ti is below the set temperature T1 (302). If the condition is not satisfied, the process returns to 301, and if the condition is satisfied, the compressor operating frequency f is detected (303). Then, it is determined whether the frequency is equal to or higher than the set frequency fa (304). If the frequency is equal to or higher than the set frequency fa, the compressor is immediately stopped (305) to protect the compressor. By this control, by limiting the operation to the set frequency or higher, it is possible to surely avoid a refrigeration cycle failure due to a large amount of refrigerant gas escape or the like only on the indoor side.

Next, a fourth embodiment of the present invention will be described. FIG. 4 is a schematic block diagram of an air conditioner according to the fourth embodiment of the present invention. In FIG. 4, 31 is a compressor operating frequency control means capable of varying the compressor operating frequency (f), 32
Is a compressor operating frequency detecting means for detecting the compressor operating frequency (f), and 33 is a set frequency (f) in which the compressor operating frequency (f) detected by the compressor operating frequency detecting means is stored in advance in the set frequency storing means. frequency comparison means for detecting and outputting that the signal is equal to or more than fa), and 34 is a frequency continuous output detection for detecting and outputting that a signal equal to or more than the frequency boundary value (fa) by the frequency comparison means is continuously output for a set time or more. It is a means.

FIG. 9 is a flow chart of this control flow. First, the heat exchange inlet pipe temperature Th and the room temperature Ti are detected (401), and the heat exchanger inlet pipe temperature Th is detected.
It is determined whether the value of the temperature difference T between the room temperature Ti and the room temperature Ti is lower than the set temperature T1 (402). If the condition is not satisfied, the process returns to 401, and if the condition is satisfied, the compressor operating frequency f is detected (403). ), It is determined whether the frequency is equal to or higher than the set frequency fa (404). If the frequency is equal to or higher than the set frequency fa, the compressor operating time t is measured (405), and the compressor operating time t is compared with the set time t1 (406). ), After elapse of the set time t1, it is judged whether or not the compressor is continuously the set frequency fa or more for the set time t1 (407), and if the condition is not satisfied, the measured time t is cleared to 401. return,
If the conditions are met, stop the compressor immediately (40
8) Protect the compressor. By this control, by limiting the operation to the set frequency or more and the set time continuously, it is possible to surely avoid the refrigeration cycle failure due to a large amount of refrigerant gas escape, etc., only on the indoor side.

[0026]

As is apparent from the above embodiment, the present invention is
During heating operation of the air conditioner, when the temperature difference between the heat exchange inlet pipe temperature and the room temperature is smaller than the set temperature difference (T1), the compressor is stopped to avoid a defective refrigeration cycle due to a large amount of refrigerant gas escape, etc. Has the effect of being able to improve the life and reliability of the compressor because it can be done only inside the room, and it is possible to control the protection of the compressor with the information inside the room, and it is possible to control without an electronic control device at all outdoors. Therefore, it has many effects such as cheap and easy control.
In addition, since the temperature of the heat exchange inlet pipe connected to the refrigerant inlet side of the indoor heat exchanger is the refrigerant superheated gas temperature, it is possible to make a stable determination without being affected by the indoor air volume, etc. Since the determination is made based on the difference, it is possible to make an accurate determination without being affected by the indoor temperature.

Further, according to the present invention, during the heating operation, when the temperature difference between the heat exchange inlet pipe temperature and the room temperature is smaller than the set temperature difference (T1) for a set time (t1) continuously from the start of the compressor operation,
By stopping the compressor, it is possible to reliably avoid a refrigeration cycle failure due to a large amount of refrigerant gas escape, etc., only on the indoor side, which has the effect of improving the life and reliability of the compressor, and the information on the indoor side Since the compressor can be protected and controlled and can be controlled even if there is no electronic control device outside the room, it has many effects such as cheap and easy control.

Further, according to the present invention, during the heating operation, the compressor operating frequency (f) is equal to or higher than the set frequency (fa), and the temperature difference between the heat exchange inlet pipe temperature and the room temperature is the set temperature difference (T).
1) When it is smaller than this, by stopping the compressor when it is smaller, avoidance of refrigeration cycle failure due to large amount of refrigerant gas escape, etc. is surely possible by limiting operation to above the set frequency, improving the life and reliability of the compressor. It has an effect that can be achieved.

Further, the present invention continuously detects that the compressor operating frequency (f) is equal to or higher than the set frequency (fa) during the heating operation for the set time (t1), and the heat exchange inlet pipe temperature and the room temperature. When the temperature difference is smaller than the set temperature difference (T1) continuously for the set time (t1), the compressor is stopped to avoid the refrigeration cycle failure due to a large amount of refrigerant gas escape, etc. By limiting the operation to continuous operation for a certain period of time, the operation is surely possible and the life and reliability of the compressor can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of an air conditioner according to a first embodiment of the present invention.

FIG. 2 is a schematic block diagram of an air conditioner according to a second embodiment of the present invention.

FIG. 3 is a schematic block diagram of an air conditioner according to a third embodiment of the present invention.

FIG. 4 is a schematic block diagram of an air conditioner according to a fourth embodiment of the present invention.

FIG. 5 is a refrigeration cycle diagram of the air conditioner of the present invention.

FIG. 6 is a control flowchart in the first embodiment of the present invention.

FIG. 7 is a control flowchart in the second embodiment of the present invention.

FIG. 8 is a control flowchart in the third embodiment of the present invention.

FIG. 9 is a control flowchart in the third embodiment of the present invention.

FIG. 10 is a refrigeration cycle diagram of a conventional air conditioner.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Four-way valve 3 Outdoor heat exchanger 5 Pressure reducer 6 Indoor heat exchanger 10 Indoor temperature detecting means 11 Heat exchange inlet pipe temperature detecting means 12 Temperature difference detecting means 13 Temperature difference comparing means 14 Set temperature difference storing means 15 compressor stopping means 21 operating time measuring means 22 set time storing means 23 operating time comparing means 24 compressor continuous operation detecting means 25 continuous output detecting means 31 compressor operating frequency control means 32 compressor operating frequency detecting means 33 set frequency storage Means 34 Frequency comparison means 25 Frequency continuous output detection means

Claims (4)

[Claims] 1. A refrigeration cycle equipped with a compressor, a four-way valve, an indoor heat exchanger, a pressure reducing device, and an outdoor heat exchanger,
During the heating operation, the indoor temperature detecting means for detecting the indoor temperature, the heat exchange inlet pipe temperature detecting means for detecting the temperature of the inlet pipe of the indoor heat exchanger, and the heat exchange inlet pipe temperature detecting means for detecting the temperature. The temperature difference detecting means for detecting the difference between the heat exchange inlet pipe temperature and the indoor temperature detected by the indoor temperature detecting means, and the temperature difference detected by the temperature difference detecting means are stored in advance in the set temperature difference storing means. The temperature difference comparing means for detecting and outputting that the temperature difference is smaller than the set temperature difference is provided, and the temperature difference decreasing signal by the temperature difference comparing means
A compressor protection control device for an air conditioner, comprising compressor stop means for stopping the compressor. 2. The heating time of the air conditioner is compared with the operating time measuring means for measuring the time from the start of the compressor operation and the operating time of the compressor and the preset time stored in the preset time storage means. The temperature by the compressor continuous operation detecting means and the temperature difference comparing means for detecting whether or not the compressor is continuously operating for the set time after the set time elapses from the start of the compressor operation by providing the operation time comparing means. A continuous output detecting means for detecting and outputting the continuous output of the difference reduction signal for a set time or more is provided, and the compressor stopping means for stopping the compressor by the compressor continuous operation detecting means and the continuous output detecting means. The compressor protection control device for an air conditioner according to claim 1, further comprising: 3. A compressor operating frequency control means capable of varying a compressor operating frequency, a compressor operating frequency detecting means for detecting the compressor operating frequency, and a compressor operating frequency detected by the compressor operating frequency detecting means. Is provided in the set frequency storage means and is provided with frequency comparison means for detecting and outputting that the preset frequency is equal to or higher than the preset frequency, and it is detected by the frequency comparison means that a signal above the frequency boundary value is output, and the compressor is turned on. The compressor protection control device for an air conditioner according to claim 1, further comprising a compressor stopping means for stopping. 4. A compressor operating frequency control means capable of varying a compressor operating frequency, a compressor operating frequency detecting means for detecting the compressor operating frequency, and a compressor operating frequency detected by the compressor operating frequency detecting means. Is provided in the set frequency storage means, and frequency comparison means for detecting and outputting that the frequency is equal to or higher than the preset frequency stored in advance is provided. A frequency continuous output detecting means for detecting and outputting is provided, and a compressor stopping means for stopping the compressor by the frequency continuous output detecting means, the compressor continuous operation detecting means and the continuous output detecting means is provided. 2. The compressor protection control device for an air conditioner according to 2.