JPH0375447A - Temperature control apparatus for compressor - Google Patents

Abstract

PURPOSE:To maintain the temperature of a compressor at a given value by measuring a time period from a time at which the temperature of the compressor reaches a given set value below a predetermined upper limit value and returning the opening of a refrigerant flow rate controller to a normal opening at a time when the measured time period has elapsed by a predetermined amount. CONSTITUTION:Such control signals as a release control signal depending on a set upper limit temperature To1 and another release control signal depending on a set time period from a set temperature, for example To3, between the set upper limit temperature To1 and a set lower limit temperature To2 are fed to a refrigerant flow rate controller. That is, when the temperature of a compressor exceeds the set upper limit temperature To1, a solenoid valve 19 is opened and the cooling operation of the compressor is conducted. Thus, when the temperature of the compressor fall to the set intermediate temperature To3, a time period from then is measured. When the measured time period exceeds a set value, the solenoid valve 19 is controlled to be closed regardless of the set lower limit temperature To2 and a refrigeration cycle is returned to a normal operation. Thus, the temperature control of the compressor can be surely performed and the air control of an air for keeping comfortable temperature can be executed.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a temperature control device for a compressor, and in particular, the present invention relates to a temperature control device for a compressor. The present invention relates to a compressor temperature control device that accurately controls the temperature of a compressor.

(Prior Art) Generally, an air conditioner has a heat pump type refrigeration cycle as shown in FIG. A case will be described in which an air conditioner using this heat pump type refrigeration cycle is operated as a cooler. The refrigeration cycle is
The refrigerant compressed by the compressor 10 is returned to the compressor 10 through the discharge pipe 11, the four-way valve 12, the condenser 13, the throttle valve 14, the evaporator 15 provided in the indoor unit, and the four-way valve 12. , indoor air is cooled by the evaporator 15, and indoor air conditioning is performed.

In an air conditioner with such a refrigeration cycle,
During air conditioning, the compressor 10 may be operated at high temperatures due to various factors. If this high temperature operation continues, the motor windings, lubricating oil, etc. of the compressor 10 may deteriorate, and the compressor 10, that is, the air conditioner, may become unable to operate.

Therefore, a temperature detector 16 is provided in the discharge pipe 11 of the compressor 10, and the temperature of the refrigerant discharged from the discharge pipe 11 of the compressor 10 is detected. Therefore, when this temperature detector 16 detects the predetermined upper limit set temperature Tol, this temperature detection signal is sent to the temperature control section 17. A control signal is generated from the temperature control section 17, and the control signal is sent to the solenoid valve 19 of the bypass pipe 20, that is, the refrigerant flow rate control section, between the capillary tube 18 and the solenoid valve 19, which are provided in parallel with the throttle valve 14. is manually opened to open the refrigerant flow control section.

Therefore, the flow rate of refrigerant flowing from the condenser 13 of the refrigeration cycle to the compressor 10 via the evaporator 15 is increased, thereby reducing the cooling capacity of the evaporator 15, and
The temperature of compressor 10 is reduced.

FIG. 5 is a temperature characteristic curve with the vertical axis representing the temperature T of the refrigerant discharged from the compressor 10 and the horizontal axis representing the operating time t of the compressor 10. When the compressor 10 is operated here, the discharge refrigerant temperature T rises and becomes higher as time passes. This rising temperature reaches the maximum temperature Too when the time reaches to.
become. After that, depending on the air conditioning conditions, the maximum temperature To
o, or exhibits a downward phenomenon as shown in FIG.

In the compressor 101 having such a temperature characteristic curve, when the compressor 10 reaches a predetermined upper limit setting temperature of approximately 100° C. or higher, the motor windings, lubricating oil, etc. may deteriorate due to the temperature.

Therefore, when the discharge refrigerant temperature discharged from the compressor 10 exceeds the predetermined upper limit setting temperature To1, the temperature is detected by the temperature detector 16, and the temperatures f, , i are sent to the temperature control section 17. When the temperature control section 17 receives this temperature signal, a control signal is sent from the temperature control section 17 to the solenoid valve 19, which is a refrigerant flow rate control section, and the solenoid valve 19 is opened. As a result, the flow rate of refrigerant sent from the condenser 13 of the refrigeration cycle to the compressor 10 and the like via the evaporator 15 is increased.

Therefore, the cooling capacity of the evaporator 15 is reduced, and the temperature of the compressor 10 is also reduced. When the temperature of the compressor 10 is lowered, the temperature of the refrigerant discharged from the compressor 10 is also lowered.

In this way, when the temperature of the compressor 10 is lowered and the discharge refrigerant temperature reaches the predetermined lower limit set temperature Ta2 of 80° C. for normal operation, this temperature signal is transmitted to the temperature controller 17.
is sent to the solenoid valve 19 via the solenoid valve 19, and one of the solenoid valves is closed.

Therefore, the increase in the refrigerant flow rate that had been sent to the evaporator 15 and the compressor 10 is canceled, the cooling function of the evaporator 15 is returned to the normal state, and the refrigeration cycle is returned to normal operation.

By controlling the refrigerant flow rate to increase in this manner, the compressor 10 is operated at a temperature below the upper limit set temperature Tol, and deterioration of the motor windings, lubricating oil, etc. of the compressor 10 is prevented.

Here, in the temperature characteristic curve shown in FIG. 5, when the temperature of the compressor exceeds the upper limit set temperature To1, the refrigerant flow rate control section is opened to increase the refrigerant flow rate, and the temperature of the compressor is changed from the upper limit set temperature Tol to the lower limit. The temperature control range in which the temperature is lowered to the set temperature Ta2 will be referred to as the A zone. Moreover, the temperature range in which the refrigeration cycle is normally operated in the temperature range from the upper limit set temperature Tol to the lower limit set temperature Ta2 is referred to as the B zone.

(Problems to be Solved by the Invention) In an air conditioner having such a refrigeration cycle, the lower limit temperature TO2 and the upper limit temperature Tol are controlled to open and close one solenoid valve for controlling the temperature of the refrigerant discharged by the compressor.
When controlling the temperature within a narrow range of, for example, 95°C to 85°C in order to accurately control the temperature, the solenoid valve will be opened and closed frequently, and this frequent operation will cause the flow in the refrigeration cycle to decrease. There is a problem in that the refrigerant becomes unstable, causing fluctuations in room temperature and making it impossible to control comfortable air conditioning.

In addition, if a wide temperature range is set between the upper and lower set temperatures, - once the single solenoid valve is opened, it will be difficult to return to the original state, resulting in insufficient cooling capacity of the air conditioner and proper air conditioning. There is a problem with it disappearing.

In order to solve the above-mentioned problems, the present invention appropriately controls the air conditioner so that the temperature control range of the compressor is not too narrow and does not return to normal operation for a long time, and the temperature of the compressor is maintained at a predetermined level. The object of the present invention is to obtain a temperature control device for a compressor that maintains the temperature of a compressor.

[Structure of the invention]

(Means for Solving the Problems) The present invention includes a temperature detector provided in a discharge pipe of a compressor to detect the temperature of the discharged refrigerant discharged from the compressor, and a temperature sensor for receiving a temperature signal from the temperature detector. a temperature control section that sends a control signal to increase the opening degree of the refrigerant flow rate control section when the discharge refrigerant temperature reaches a predetermined upper limit setting temperature, and an arbitrary set temperature that is provided in the temperature control section and is below the predetermined upper limit setting temperature. The refrigerant flow rate control section is provided with a time control section that controls the time from the time when the refrigerant flow rate control section is reached, and returns the opening degree of the refrigerant flow rate control section to the normal opening degree when the measured time period has elapsed for a predetermined period of time.

(Function) Upper limit set temperature T to prevent the refrigerant temperature discharged from the compressor from becoming high and deteriorating the motor windings, lubricating oil, etc. of the compressor.
When the temperature of the discharged refrigerant reaches ol, the temperature detector detects the temperature of the discharged refrigerant. The temperature signal from this temperature sensor is sent to the refrigerant flow rate control unit via the temperature control unit, and the opening degree of this refrigerant flow rate control unit is increased, increasing the flow rate of refrigerant flowing from the condenser to the evaporator and compressor. Ru. This control to increase the refrigerant flow rate reduces the cooling capacity of the evaporator and lowers the temperature of the compressor, thereby preventing deterioration of the motor windings of the compressor, the so-called lubricant.

In the cooling control of the compressor, the temperature of the refrigerant discharged from the compressor reaches an arbitrary set temperature Ta2 that is lower than the upper limit set temperature To1, and when a predetermined period of time has elapsed after reaching this set temperature Ta2, the refrigerant flow rate of the refrigerant flow rate controller is increased. The increase control is canceled, the flow rate of refrigerant sent from the condenser to the evaporator, compressor, etc. is brought to a normal state, and the refrigeration cycle is returned to normal operation. This time control of the refrigerant flow rate provides comfortable air conditioning control of the air conditioner and accurate temperature control of the compressor.

(Embodiment) An embodiment of the temperature control device for a compressor according to the present invention will be described below with reference to the accompanying drawings. Note that the same parts as in FIGS. 4 and 5 are designated by the same reference numerals, and detailed explanation thereof will be omitted.

The refrigeration cycle of FIG. 1 is similar to a conventional refrigeration cycle. The solenoid valve 19 of the bypass pipe 20 of this refrigeration cycle is controlled by a flow rate control signal from the temperature control section 17.

The control signals in the present invention are a release control signal based on the upper limit set temperature Tol, the upper limit set temperature Tol, and the lower limit set temperature T.
Set temperature in the middle of a2, for example, Ta2 (Tol≧To3>
A release control signal based on the set time from Ta2) is sent to the refrigerant flow rate control section.

In other words, the temperature of the compressor is the upper limit setting temperature To1 of the control device.
At this point, one solenoid valve is opened and the compressor is cooled in the same manner as in the conventional system.

In this way, when the temperature of the compressor decreases and reaches the above-mentioned intermediate set temperature Ta2, the time elapsed after reaching that temperature is measured, and if that time exceeds the set time, regardless of the lower limit set temperature Ta2, The solenoid valve 19 is controlled to close, and the refrigeration cycle is returned to normal operation.

These refrigerant flow rate controls will be explained according to the flowchart shown in FIG. For the purpose of explaining this flowchart, from the temperature above the upper limit setting temperature To1 of the compressor to the intermediate setting temperature Ta
The temperature control range in which the compressor 10, etc. is controlled at a low temperature by increasing the refrigerant flow rate between 2 and 2 is called the Ao zone. The temperature control range in which low temperature control is performed and the control signal of the temperature control unit 17 is measured over time is called the C zone, and is normal operation without temperature control from the lower limit set temperature Ta2 to the upper limit set temperature Tol. The area where this is done is called the B zone (
(See Figure 3).

Here, when the compressor 10 is operated and air conditioning is performed, the temperature of the refrigerant discharged from the compressor 10 is detected by the temperature detector 16. When this detected temperature signal is sent to the temperature control section 17, it is determined whether or not this detected temperature signal is within the temperature range of zone B (Sl). When the temperature is within the B zone temperature range, the temperature control section 17 does not send a control signal to the solenoid valve 19 and it remains closed (S2). In addition, the temporal control is also cleared, and the compression 8110 continues to operate (S3
).

When the temperature of the temperature detector 16 becomes equal to or higher than the upper limit temperature To1 due to the operation of the compressor 10, this temperature signal is sent to the temperature control section 17, which first determines whether or not the temperature is within the B zone temperature range. (Sl). In this case, the temperature signal is B
Since the temperature is not within the zone temperature range, it is then determined whether the temperature is within the AO zone temperature range (S4). When the temperature is within this AO zone temperature range, a control signal is sent from the temperature control section 17 to one solenoid valve, and the solenoid valve 19 is opened (S5). When this electromagnetic valve 19 is opened, the flow from the condenser 13 to the evaporator 15 is reduced.
The flow rate of refrigerant sent to is increased, the cooling capacity of the evaporator 15 is reduced, and the compressor 10 is lowered to a lower temperature,
Deterioration of the windings etc. is prevented.

Due to this low temperature control, the refrigerant discharged from the compressor 10 becomes lower than the intermediate set temperature To3, moves to the C zone, and when it is confirmed that it is in the C zone (51, S4), upon receiving this confirmation signal, the temperature control section 17, time measurement of the control signal sent to the refrigerant flow rate control section is started (S6).

This time measurement control is performed when the temperature control range from the upper limit set temperature Tol to the intermediate set temperature Ta2 is narrow, e.g. 95°C.
In the temperature range from 85° C. to 85° C., a long period of time tm, for example 10 minutes, is counted during which the refrigerant of the air conditioner does not become unstable. In addition, from the upper limit setting temperature l to the intermediate setting temperature Ta2
For example, if the temperature control range is wide from 100℃ to 80℃
In the temperature range of .degree. C., a short time tn, for example, 3 minutes, during which the cooling capacity of the air conditioner is not insufficient is counted. This time t
m or tn may be a preset time tc set in advance by an air conditioner or the like, for example, 5 minutes.

Therefore, if the counting time is less than tc, cooling and time measurement in the C zone continues. Furthermore, when the tc time is measured (87), the temperature control range is forcibly moved from the C zone to the B zone (S8). This zone transfer closes the electromagnetic valve 19, cancels the increase in the refrigerant flow rate, and returns the refrigeration cycle to normal operation as described above.

By controlling the refrigerant temperature of the compressor in this manner, the compressor 10 is brought to a temperature that does not deteriorate its motor windings, lubricating oil, etc., and the air conditioner is operated with an increased amount of refrigerant in an extremely short period of time. It is never driven for long periods of time. Therefore, the air conditioner is not operated with an unstable refrigerant, and the cooling capacity is not insufficient, so that comfortable air conditioning is achieved.

In the above embodiment, the flow rate of the refrigerant was controlled by controlling the opening and closing of the electromagnetic valve 19, but the opening degree of the throttle valve 14 may be controlled directly.

Moreover, although the description has been given of an air conditioner operated as a cooler, almost the same control can be performed when the air conditioner is operated as a heater by switching the refrigeration cycle.

〔Effect of the invention〕

As described above, the present invention detects the temperature of the refrigerant discharged from the compressor using a temperature detector, and controls the refrigerant flow rate controller via the temperature controller based on the temperature detected by the temperature detector, thereby controlling the temperature of the compressor. When the temperature of the refrigerant discharged from the compressor reaches the set temperature below the upper limit set temperature, the control signal of the temperature control section is time-controlled and the opening degree of the refrigerant flow rate control section is changed to the normal opening degree. This prevents the refrigerant flow control unit from opening and closing frequently or from not returning to its original state for a long period of time, ensuring accurate compressor temperature control and improving the comfort of the air conditioner. air conditioning control.

[Brief explanation of drawings]

FIG. 1 is a refrigeration cycle used in the temperature control device for the compressor of the present invention, FIG. 2 is a temperature characteristic curve diagram of the compressor used in the refrigeration cycle of FIG. 1, and FIG. Flowchart explaining the control operation of the temperature control unit shown in FIG.
The figure shows a commonly used conventional refrigeration cycle,
The figure is a temperature characteristic curve diagram of the compressor used in the refrigeration cycle of FIG. 4. DESCRIPTION OF SYMBOLS 10... Compressor, 11... Discharge pipe, 12... Four-way valve, 13... Condenser, 14... Throttle valve, 15...
Evaporator, 16... Temperature detector, 17... Temperature control unit, 18... Capillary tube, 19... Solenoid valve,
20... Bypass pipe.

Claims (1)

[Claims] a temperature detector installed in the discharge pipe of the compressor to detect the temperature of the discharged refrigerant discharged from the compressor; and when receiving a temperature signal from the temperature detector, the temperature of the discharged refrigerant of the compressor reaches a predetermined upper limit setting temperature. a temperature control section that sends a control signal to increase the opening degree of the refrigerant flow control section; A temperature control device for a compressor, comprising: a time control section that returns the opening degree of the refrigerant flow rate control section to the normal opening degree when a predetermined measurement time has elapsed.