KR20090071399A - Air conditioner - Google Patents

Abstract

An air conditioner is provided to charge refrigerant at the optimum condition even if the high pressure is changed with the disturbance. An air conditioner comprises: a pressure control part(C1) controlling the discharging rate of a compressor to make the evaporating pressure of refrigerant at an evaporator reach a set up value; an expansion valve control part(C2) controlling an expansion valve(3) in order to make the degree of superheat of the refrigerant at an outlet of the evaporator reach a positive value; a relation memory part(C4) memorizing the relationship of optimum refrigerant charging amount at between the saturation temperature of the refrigerant and the refrigerant temperature at the evaporator outlet; a ideal refrigerant temperature output unit(C5) calculating the ideal refrigerant temperature, the refrigerant temperature at the evaporator outlet, if the optimum amount of the refrigerant is charged; and a proper refrigerant charging amount determining part(C6) determining whether the refrigerant temperature is under the ideal refrigerant temperature.

Description

Air Conditioning Equipment {AIR CONDITIONER}

The present invention relates to an air conditioner and the like having a function of determining whether or not the amount of refrigerant charged in the refrigerant circuit is appropriate.

In the separator type air conditioner that connects the outdoor unit and the indoor unit at the time of pipe construction, a method of filling a refrigerant during local construction has been adopted. At this time, it is necessary to fill the refrigerant by an optimum amount, but conventionally, the refrigerant capacity is calculated and filled from the piping volume.

Moreover, in such a filling method, since the piping volume changes according to the local situation, and it is difficult to estimate the exact quantity, as shown in JP 62-158966 A, the trial run after local construction is performed. At the time of cooling, the supercooling degree of the refrigerant at the condenser outlet is detected while performing the cooling operation so that the superheat degree of the refrigerant at the evaporator outlet becomes a predetermined value, and whether or not the amount of refrigerant charged in the refrigerant circuit is appropriate from the value of this subcooling degree. It is also being developed to be able to determine.

In addition, in such a configuration, an error occurs in the amount of refrigerant filling due to the temperature inside and outside of the room, so that the optimum amount of refrigerant cannot be filled. As a result of this improvement, as shown in Japanese Patent Application Laid-Open No. 2006-23072, the suction of the compressor is performed. When the pressure and discharge pressure are controlled to a certain value, the refrigerant is charged while the superheat degree (SH) is at a fixed value, the supercooling degree (SC) at the outlet of the condenser is sensed, and the amount of refrigerant charge when the optimum SC value is achieved. Also disclosed is a configuration that is determined to be optimal.

However, the following problems may occur in the configuration of Japanese Patent Laid-Open No. 2006-23072.

The first problem is that the working time according to the refrigerant filling is long. That is, if the high pressure is to be made constant by the fan control of the outdoor unit, in order to keep the cycle state of the outdoor unit constant, depending on the responsiveness of the entire system, it takes about 10 minutes until the high pressure is stabilized. It becomes bottleneck and cannot shorten working time greatly.

The second problem is that the high pressure is changed when the wind around the outdoor unit is changed due to the gust, etc. during the detection of the supercooling degree, so that constant control of the high pressure by the fan provided in the condenser is impossible, resulting in an error in the refrigerant filling amount. For example, when the air volume of the outdoor unit changes by about 10% due to the gust of wind, the supercooling degree changes by about 2 degrees, and an error of about 6% occurs in the amount of refrigerant filling.

The third problem is that when the refrigerant cylinder, which is the source of refrigerant injection, receives direct sunlight, or the operator warms the refrigerant cylinder with a dryer, when the temperature of the refrigerant cylinder is increased and the internal pressure is increased, the refrigerant flow rate is increased. In this case, moisture in refrigerant is sucked into the compressor. As a result, the reliability of the compressor is deteriorated due to suction of moisture refrigerant, or in the case of an accumulator or low pressure shell type compressor, liquid refrigerant may remain in the oil reservoir of the compressor, thereby increasing the error of the refrigerant amount detection.

In response to this problem, the present invention relates to the relationship between the saturation temperature of the refrigerant determined by the refrigerant discharge pressure from the compressor and the refrigerant temperature at the outlet of the condenser. The inventors of the present invention have found that the inventors have made diligent efforts to find the main object of the present invention is that the working time can be drastically shortened in the refrigerant filling process, and there is no error even when disturbance occurs. It is possible to fill the optimum amount of refrigerant, and to provide an air conditioner and the like that can increase the reliability of the compressor.

That is, the air conditioner according to the present invention includes a compressor having a variable discharge amount, a condenser, an expansion valve, and an evaporator, and forms a refrigerant circulation circuit in which the refrigerant circulates in this order. And a pressure control unit for controlling the discharge amount of the compressor so that the evaporation pressure of the refrigerant in the evaporator is a predetermined constant value, and an expansion valve so that the superheat degree of the refrigerant at the evaporator outlet when the evaporation pressure is set to the constant value is a constant value. An expansion valve control unit for controlling the control unit; and a relation memory unit for storing a relationship between the saturation temperature of the refrigerant determined by the refrigerant discharge pressure from the compressor and the optimum refrigerant charge amount of the refrigerant temperature at the outlet of the condenser; By reference, the abnormal refrigerant temperature calculation unit for calculating the abnormal refrigerant temperature which is the refrigerant temperature at the outlet of the condenser when the optimum amount of refrigerant is filled from the measured pressure of the refrigerant discharged from the compressor, and the measured refrigerant temperature measured at the outlet of the condenser Appropriate refrigerant filling amount to determine whether or not the abnormal refrigerant temperature or less, and output the determination result It is characterized by including a determination unit.

According to such a configuration, it is possible to perform the filling of the optimum refrigerant amount by determining whether the measured refrigerant temperature measured at the outlet of the condenser is equal to or less than the abnormal refrigerant temperature at the optimum filling amount determined by the refrigerant discharge pressure from the compressor. Further, since the judgment is made based on the refrigerant discharge pressure of the compressor, it is possible to prevent an error in the amount of refrigerant filling even if the high pressure is changed by any disturbance.

In addition, since it is not necessary to control the high pressure constantly, for example, the time taken to keep the high pressure constant by the fan of the outdoor unit or the like during the refrigerant filling can be eliminated, and the refrigerant filling operation time can be significantly shortened.

When the refrigerant is filled, it is preferable that the reliability of the compressor due to the filling of the refrigerant in the moisture state from the refrigerant cylinder serving as the refrigerant injection source and the error of the refrigerant amount detection can be prevented from increasing. Therefore, in order to heat the refrigerant in the wet state and make it overheated, the air conditioner detects the refrigerant filling port for filling the refrigerant from the refrigerant source into the refrigerant circulation circuit, and the moisture detection for detecting the moisture of the refrigerant sucked into the compressor. Means for connecting the compressor, the high pressure line for connecting the compressor and the condenser, the bypass line for opening and closing the low pressure line for connecting the evaporator and the compressor, and the refrigerant filling line. In this case, the bypass line opening and closing control unit for opening the bypass line may be further provided.

In order to limit the filling of the refrigerant at a speed higher than a predetermined filling speed so that the refrigerant in the moisture state is not filled, the refrigerant filling port is opened in the low pressure line, and the opening of the bypass line to the low pressure line is It is preferably set at a position opposite to the refrigerant filling port.

In another embodiment for preventing the refrigerant from being filled with moisture, the bypass line is connected to a refrigerant filling line which opens the refrigerant filling port in the low pressure line and connects a separately provided refrigerant source to the refrigerant filling port. It can be mentioned.

In the refrigerant filling process, it is possible to drastically shorten the working time and at the same time, a refrigerant filling system capable of filling the optimum amount of refrigerant without errors even in the event of disturbance, is a compressor, a condenser, an expansion valve and an evaporator of a variable discharge amount. And a pressure control unit for use in an air conditioner in which a refrigerant circulation circuit in which refrigerant is circulated in this order is used, and controls a discharge amount of the compressor such that the evaporation pressure of the refrigerant in the evaporator is a predetermined constant value. And an expansion valve control unit for controlling the expansion valve so that the superheat degree of the refrigerant at the evaporator outlet when the evaporation pressure is set to the constant value, and the saturation temperature and the condenser of the refrigerant determined by the refrigerant discharge pressure from the compressor. A relation memory section for storing a relationship between an optimum refrigerant charge amount of a refrigerant temperature at an outlet and the pipe; The abnormal refrigerant temperature calculation unit for calculating the abnormal refrigerant temperature which is the refrigerant temperature at the condenser outlet when the optimum amount of refrigerant is filled from the measured pressure of the refrigerant discharged from the compressor with reference to the meter storage unit, and the measurement measured at the outlet of the condenser What is necessary is just to provide the appropriate refrigerant filling quantity determination part which judges whether a refrigerant temperature is below the said abnormal refrigerant temperature, and outputs the determination result.

In the refrigerant filling process, a significantly shortening of the working time can be achieved, and a refrigerant filling program that enables optimum filling of the refrigerant amount without errors even in the event of a disturbance, includes a compressor with a variable discharge amount, a condenser, and an expansion valve. , A refrigerant charging program used for an air conditioner having an evaporator and a refrigerant circulation circuit in which refrigerant is circulated in this order, and controlling the discharge amount of the compressor so that the evaporation pressure of the refrigerant in the evaporator becomes a predetermined value. The pressure control step to control the expansion valve so as to control the expansion valve so that the superheat degree of the refrigerant at the evaporator outlet when the evaporation pressure is set to the constant value is a constant value, and the refrigerant discharge pressure from the compressor. The relationship between the saturation temperature of the refrigerant and the optimum refrigerant charge amount between the refrigerant temperature at the outlet of the condenser On the basis of the stored relationship, the abnormal refrigerant temperature calculating step of calculating the abnormal refrigerant temperature which is the refrigerant temperature at the outlet of the condenser when the optimum amount of refrigerant is filled from the measured pressure of the refrigerant discharged from the compressor, and the measurement at the outlet of the condenser And determining whether the measured measured refrigerant temperature is equal to or lower than the abnormal refrigerant temperature, and causing the computer to execute an appropriate refrigerant filling amount determination step of outputting the determination result.

As described above, according to the present invention, in the refrigerant filling step, the filling time can be significantly shortened, and there is no need to keep the high pressure constant, and the refrigerant can be filled with the optimum filling amount even when the high pressure is changed due to disturbance. have. Specifically, in the air conditioner of the single pipe, it is possible to shorten about 20% of the conventional working time by eliminating the waiting time for controlling the high pressure constantly.

EMBODIMENT OF THE INVENTION Hereinafter, one Embodiment of this invention is described with reference to drawings.

As shown in FIG. 1, the air conditioner 100 of the present embodiment includes a compressor 1 having a variable discharge amount type, a condenser 2, an expansion valve 3, and an evaporator 4, and in this order. The refrigerant circulation circuit in which the refrigerant circulates is formed. In this embodiment, the oil separator 5 is provided on the high pressure line L1 connecting the compressor 1 and the condenser 2, and the evaporator 4 and the compressor 1 are provided. The accumulator 6 and the refrigerant filling port PL4 are provided on the low pressure line L2 to be connected. In addition, the high pressure line (L1) and the low pressure line (L2) between the compressor (1) and the oil separator (5) are connected to the bypass line (L3) provided with a solenoid valve (10) in the middle. It consists. The bypass line L3 is a pipe used to bypass hot gas in order to adjust the high and low pressure between the high pressure line L1 and the low pressure line L2.

Each part is explained in full detail.

As is well known, the compressor 1 compresses and discharges the sucked gas refrigerant, and various types such as a rotary type and a piston type can be used.

The condenser 2 condenses the gas refrigerant discharged from the compressor 1 in a state of maintaining a high pressure, thereby making it in a supercooled state. Outside the fan 21 for promoting heat exchange is provided. Moreover, the temperature sensor 8 is provided in the piping of the outlet of this condenser 2.

The expansion valve 3 throttles and expands the liquid refrigerant sent from the condenser 2 to a low pressure state. In addition, it is configured to adjust the amount of the liquid refrigerant flowing into the evaporator (4).

The evaporator 4 is to evaporate the liquid refrigerant at a low pressure to make it superheated.

The oil separator 5 separates oil contained in the refrigerant discharged from the compressor 1, and connects the oil separator 5 and the low pressure line L2 to the oil return line OL and the low pressure line. It returns to the said compressor 1 through L2. Downstream of this oil separator 5, a pressure sensor 7 for measuring the pressure of the discharged refrigerant is provided, and an oil return line solenoid valve OV is provided in the middle of the oil return line OL.

The accumulator 6 is configured to separate the refrigerant into a gas refrigerant and a liquid refrigerant, and return only the gas refrigerant to the compressor. Downstream of this accumulator 6, a pressure sensor 91 and a temperature sensor 92 are provided as moisture detection means of the refrigerant. When the measurement temperature of this temperature sensor 92 is lower than the saturation temperature calculated | required from the pressure measured by the pressure sensor 91, it is comprised so that it may determine that it is a moisture state.

The refrigerant filling port PL4 connects the refrigerant cylinder S at the time of refrigerant filling, and as shown in the enlarged view of FIG. 2, the bypass line L3 is connected upstream of the accumulator 6. It is provided to face the port PL3.

The solenoid valve 10 is for opening and closing the bypass line L3.

In addition to this configuration, the air conditioner 100 is provided with a control mechanism C for controlling the compressor 1, the expansion valve 3, and the solenoid valve 10.

The control mechanism C has at least a hardware configuration including a CPU, a memory, various driver circuits, and the like. The control mechanism C cooperates with each other according to a program stored in the memory, thereby exhibiting various functions.

In this embodiment, as shown in the functional block diagram of Fig. 3, at least the pressure control unit C1, the expansion valve control unit C2, the solenoid valve control unit C3, the relational storage unit C4, and the abnormal refrigerant The program is configured to function as the temperature calculating section C5 and the appropriate refrigerant filling amount determining section C6.

Each part is demonstrated.

The pressure control unit C1 controls the discharge amount of the compressor 1 so that the evaporation pressure of the refrigerant in the evaporator 4 becomes a constant value stored in the memory.

The expansion valve control unit C2 controls the expansion valve 3 so that the superheat degree SH of the refrigerant at the outlet of the evaporator 4 when the evaporation pressure is set to the predetermined value becomes a constant value.

The solenoid valve control unit C3 performs opening and closing control of the solenoid valve 10 provided on the bypass line L3.

The relation storage unit C4 stores the relationship between the saturation temperature of the refrigerant determined by the refrigerant discharge pressure from the compressor 1 and the optimum refrigerant discharge amount of the refrigerant temperature at the outlet of the condenser 2. This relationship will be described in detail. For the optimum amount of refrigerant filling, between the saturation temperature of the refrigerant determined by the refrigerant discharge pressure from the compressor 1 and the refrigerant temperature at the outlet of the condenser 2, the measured data of FIG. As shown in the example, there is a rough linear relationship. Here, the slope A and the intercept B in the linear relationship are values determined for each air conditioner, and A is greater than one.

The abnormal refrigerant temperature calculation unit C5 refers to the relational storage unit C4 and the refrigerant at the outlet of the condenser 2 when the optimum amount of refrigerant is filled from the measured pressure of the refrigerant discharged from the compressor 1. The abnormal refrigerant temperature, which is the temperature, is calculated.

The appropriate refrigerant filling amount determining unit C6 determines whether or not the measured refrigerant temperature measured at the outlet of the condenser 2 is equal to or less than the abnormal refrigerant temperature, and outputs the determination result.

Next, a description will be given of a control operation during refrigerant filling with reference to the flowchart of FIG. 5.

The cooling operation is started, and the fan 21 provided in the condenser 2 is rotated at a constant rotational speed (step S1).

The expansion valve control unit C2 controls the expansion valve 3 so that the superheat degree of the refrigerant from the evaporator 4 at a low pressure value stored in the memory becomes a constant value, that is, the gas refrigerant is overheated. The state is set (step S2).

The pressure control unit C1 controls the discharge amount of the refrigerant of the compressor 1 so that the evaporation pressure of the refrigerant in the evaporator 4 is constant to a low pressure stored in the memory (step S3).

When the low pressure is kept constant, and the superheat degree of the refrigerant at the outlet of the evaporator 4 reaches a positive value, a display portion (not shown) indicates that the filling of the refrigerant can be started, and the operator starts the filling of the refrigerant ( Step S4).

As charging of the refrigerant is started, the solenoid valve control unit C3 controls the solenoid valve 10 to open the bypass line L3 and discharge the high temperature superheated gas refrigerant discharged from the compressor 1. Flows into the low pressure line L2 (step S5). At this time, as shown in FIG. 2, since the connection port PL3 of the bypass line L3 is disposed at a position opposite to the refrigerant filling port PL4, the refrigerant charged by the dynamic pressure of the superheated gas refrigerant. The inflow of is limited. In addition, the heat of the superheated gas refrigerant reduces the moisture state of the refrigerant to be filled.

While maintaining that the gas refrigerant sucked into the compressor 1 is in an overheated state (step S6), the appropriate refrigerant filling amount determining unit C6 determines whether or not the temperature at the outlet of the condenser 2 is equal to or lower than the abnormal refrigerant temperature. (Step S7).

Referring to step S7 in detail, the abnormal refrigerant temperature calculation unit C5 refers to the relational storage unit C4 at an optimum filling amount from the discharge pressure of the compressor 1 measured by the pressure sensor 7. The abnormal refrigerant temperature at the outlet of the condenser 2 is calculated. The appropriate refrigerant filling amount determining unit C6 determines whether the refrigerant temperature at the outlet of the condenser 2 measured by the temperature sensor 8 is equal to or less than the abnormal temperature.

While the proper refrigerant filling determination unit C6 determines that the refrigerant temperature at the outlet of the condenser 2 is greater than the above-mentioned temperature, the process returns to step S5, and when it is determined that the refrigerant temperature is less than or equal to, the operation of the compressor 1 is stopped. (Step S8).

The display unit (not shown) indicates that the refrigerant filling is completed (step S9), and the operator closes the filling valve (not shown) of the refrigerant cylinder S (step S10).

As described above, according to the present embodiment, the optimum refrigerant filling amount determining unit C6 has a temperature lower than the abnormal refrigerant temperature at the optimum refrigerant amount determined from the pressure of the refrigerant discharged by the compressor 1 at the outlet of the condenser 2. By determining whether or not, the optimum amount of refrigerant can be filled. More specifically, even if the high pressure fluctuates, the abnormal refrigerant temperature calculation unit C5 can calculate the abnormal refrigerant temperature at the time of filling the optimum amount of refrigerant and prevent the error in the amount of refrigerant filling, thereby filling the optimum amount of refrigerant. Can be.

In addition, since the fan 21 is rotated at a constant rotational speed and the high pressure is not constantly controlled, the time waiting for the high pressure to be stabilized can be eliminated, thereby greatly reducing the working time of the refrigerant filling operation. Can be.

In addition, by opening the bypass line L3 when the refrigerant is filled, the high temperature superheated gas refrigerant from the compressor 1 is introduced into the low pressure line L2, whereby the moisture state of the refrigerant charged can be alleviated. In addition, since the connection port PL3 and the refrigerant filling port PL4 of the bypass line L3 are disposed to face each other on the low pressure line L2, the refrigerant to be filled can be directly heated to efficiently remove moisture. can do.

In addition, since the connection port PL3 and the refrigerant filling port PL4 face each other, the flow rate of the refrigerant to be filled can be limited by the dynamic pressure of the gas refrigerant flowing into the bypass line L3. Therefore, since the refrigerant cylinder S is warmed up for some reason, it is possible to prevent the moisture refrigerant from flowing into the compressor 1 even when the inflow speed of the refrigerant to be filled is increased.

In addition, this invention is not limited to the said embodiment. The same code | symbol is attached | subjected to the member same as the said embodiment among the members in drawing.

For example, as shown in FIG. 6, in the air conditioner 100, the bypass line L3 is connected to the refrigerant filling line L4 connecting the refrigerant filling port PL4 and the refrigerant cylinder S. As shown in FIG. May be connected. The connection part L41 is provided in this refrigerant charge line L4, and the said bypass line L3 is connected to this connection part L41. By this connection part L41, the refrigerant | coolant to be filled is warmed by the superheated gas refrigerant discharged from the compressor 1, and it can prevent the refrigerant | coolant of a moisture state from entering the compressor 1. As shown in FIG.

In addition, as shown in FIG. 7, the oil return line OL also serves as the bypass line L3 which is a hot gas bypass, and a refrigerant filling port (not shown) is connected to the oil return line OL. It may be provided so as to face a port (not shown).

Furthermore, the connection port and the refrigerant filling port may be separately provided on the accumulator upstream side of the low pressure line. In the above embodiment, the operator is configured to intervene in the start and end of the coolant, but the operator performs the operation of connecting the coolant cylinder S to the coolant filling port, and starts and ends the coolant filling to the signal of the control mechanism. You may perform it automatically on the basis of it.

The external device may be a refrigerant filling system which acquires the pressure or temperature of the refrigerant from the air conditioner, controls the air conditioner so as to obtain an optimum filling amount, and fills the optimum amount of refrigerant.

The air conditioner may be a separator type which connects the pipes at the time of construction of the outdoor unit and the indoor unit. When at least one compressor of the air conditioner is variable in discharge amount, it may be arranged in parallel.

In addition, the present invention is naturally capable of various modifications without departing from the spirit thereof.

1 is a circuit diagram showing an outline of an air conditioner according to an embodiment of the present invention.

2 is a partially enlarged view of an air conditioner according to an embodiment of the present invention.

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

4 is a graph showing the relationship between the saturation temperature of the refrigerant determined by the refrigerant discharge pressure at the optimum refrigerant amount filling and the refrigerant temperature at the outlet of the condenser.

5 is a flowchart showing a refrigerant charging operation and control of the air conditioner according to the embodiment of the present invention.

6 is a partially enlarged view of an air conditioner according to another embodiment of the present invention.

7 is a circuit diagram of an air conditioner according to still another embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: air conditioner 1: compressor

2: condenser 3: expansion valve

4: evaporator L1: high pressure line

L2: Low Pressure Line L3: Bypass Line

L4: Refrigerant filling line C1: Pressure control unit

C2: expansion valve control unit C4: relational storage unit

C5: Ideal refrigerant temperature calculation part C6: Appropriate refrigerant filling judgment part

Claims (6)

In the air conditioner having a variable discharge amount compressor, condenser, expansion valve, evaporator, and formed with a refrigerant circulation circuit in which the refrigerant circulates in this order, A pressure control unit for controlling the discharge amount of the compressor such that the evaporation pressure of the refrigerant in the evaporator is a predetermined constant value; An expansion valve control unit for controlling the expansion valve so that the superheat degree of the refrigerant at the evaporator outlet when the evaporation pressure is set to the constant value is a constant value; A relation storage unit for storing a relationship between the saturation temperature of the refrigerant determined by the refrigerant discharge pressure from the compressor and the optimum refrigerant filling amount of the refrigerant temperature at the outlet of the condenser; An abnormal refrigerant temperature calculation unit for calculating an abnormal refrigerant temperature which is a refrigerant temperature at the outlet of the condenser when the optimum amount of refrigerant is filled from the measured pressure of the refrigerant discharged from the compressor, with reference to the relation storage unit; And an appropriate refrigerant filling amount determining unit for determining whether the measured refrigerant temperature measured at the outlet of the condenser is equal to or lower than the abnormal refrigerant temperature, and outputting the determination result. The method of claim 1, A refrigerant charging port for charging refrigerant from the refrigerant source to the refrigerant circulation circuit, Moisture detecting means for detecting moisture of the refrigerant sucked into the compressor; A high pressure line connecting the compressor and the condenser, a bypass line bypassing the evaporator and the low pressure line connecting the compressor so as to be openable and closed; Refrigerant filling line An air conditioner further comprising a bypass line opening and closing control unit which opens the bypass line when moisture of the refrigerant is detected by the moisture detecting means during the refrigerant filling. The method of claim 2, And the refrigerant filling port is opened in the low pressure line, and the opening of the bypass line with respect to the low pressure line is set at a position opposite to the refrigerant filling port. The method of claim 2, And the bypass line is connected to a refrigerant filling line which opens the refrigerant filling port in the low pressure line and connects a separately provided refrigerant source to the refrigerant filling port. It is a refrigerant filling system which is used in an air conditioner having a variable discharge amount compressor, a condenser, an expansion valve, an evaporator, and a refrigerant circulation circuit in which refrigerant is circulated in this order. A pressure control unit for controlling the discharge amount of the compressor such that the evaporation pressure of the refrigerant in the evaporator is a predetermined constant value; An expansion valve control unit for controlling the expansion valve so that the superheat degree of the refrigerant at the outlet of the evaporator when the evaporation pressure is set to a constant value is constant; A relation storage unit for storing a relationship between the saturation temperature of the refrigerant determined by the refrigerant discharge pressure from the compressor and the optimum refrigerant filling amount of the refrigerant temperature at the outlet of the condenser; An abnormal refrigerant temperature calculating unit for calculating an abnormal refrigerant temperature which is a refrigerant temperature at the outlet of the condenser when the optimum amount of refrigerant is filled from the measured pressure of the refrigerant discharged from the compressor, with reference to the relation storage unit; And a proper refrigerant filling amount determining unit for determining whether the measured refrigerant temperature measured at the outlet of the condenser is equal to or lower than the abnormal refrigerant temperature, and outputting the determination result.  It is a program used for an air conditioner having a variable discharge amount compressor, a condenser, an expansion valve, an evaporator, and a refrigerant circulation circuit in which refrigerant is circulated in this order. A pressure control step of controlling the discharge amount of the compressor such that the evaporation pressure of the refrigerant in the evaporator is a predetermined constant value; An expansion valve control step of controlling the expansion valve so that the superheat degree of the refrigerant at the evaporator outlet when the evaporation pressure is set to the constant value is a constant value; The relationship between the saturation temperature of the refrigerant determined by the refrigerant discharge pressure from the compressor and the optimum refrigerant filling amount of the refrigerant temperature at the outlet of the condenser is stored, and from the measured pressure of the refrigerant discharged from the compressor based on the stored relationship The abnormal refrigerant temperature calculating step of calculating the abnormal refrigerant temperature, which is the refrigerant temperature at the outlet of the condenser when the refrigerant is filled in the optimum amount, And determining whether or not the measured refrigerant temperature measured at the outlet of the condenser is equal to or lower than the abnormal refrigerant temperature, and causing the computer to execute an appropriate refrigerant filling amount determination step of outputting the determination result.

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