JP2000337740A - Refrigerant amount regulating method and refrigerant amount judging device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerant regulating method to quantitatively grasp even when a refrigerant amount in an air-conditioner is extremely small and regulate the refrigerant amount to a proper value. SOLUTION: The refrigerant amount regulation method is such a method that a multi-room type air-conditioner is caused to perform cooling operation and a refrigerant flowing out from a liquid receiver 5 is excessively cooled by a cooling device 6, how is the ratio of a refrigerant amount sealed in an air-conditioner to a proper amount is calculated by a computing device 15 based on the temperature and the pressure of a refrigerant discharged from a compressor 1, the openings of indoor expansion valves 8a and 8b, and an indoor air temperature. From the calculated ratio, a sealing and adding refrigerant amount is decided to effect primary addition, and when, after the primary addition, a refrigerant cooled by a cooling device 6 is observed in a gas liquid two-phase state by a sight glass 7, secondary addition to add a given amount of a refrigerant is executed, and the secondary addition is repeated until the refrigerant in the sight glass is brought into a liquid single-phase state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerant amount adjusting method for adjusting the amount of refrigerant enclosed in an air conditioner to an appropriate amount and a refrigerant amount judging device used for adjusting the refrigerant amount.

[0002]

2. Description of the Related Art Conventionally, several techniques have been devised and disclosed as a refrigerant amount judging device for detecting whether or not the amount of refrigerant enclosed in a refrigeration apparatus or an air conditioner is appropriate.

[0003] As a method of determining whether or not the amount of the enclosed refrigerant is an appropriate refrigerant amount, as described in Japanese Patent Publication No. 55-32991 and Japanese Patent Publication No. 56-1544, a compressor in an outdoor unit is disclosed. In a refrigeration cycle formed by circulating a heat exchanger, a decompression device and a receiver, and a decompression device and a heat exchanger in the indoor unit, a piping section connecting the receiver and the decompression device of the indoor unit, There is a method in which a sight glass for visually observing the flow of the refrigerant inside the pipe is provided, and the sight glass is used for determination. In the judgment device, the sight glass has glass on one surface, and there is also a device in which an indicator with a chemical substance called a moisture indicator is attached inside, and the state of the refrigerant passing through the inside of the sight glass is determined. It is configured so that the generation of flash gas (bubbles) in the refrigerant liquid can be detected visually through the glass, and the refrigerant in the refrigeration cycle is charged depending on whether it is a liquid refrigerant without flash gas or a gas-liquid two-phase refrigerant containing flash gas. It is determined whether the amount is appropriate. Further, in consideration of the pressure loss of the refrigerant flowing in the pipe, there is also a structure having a cooling device before flowing into the sight glass.

Further, as a method of quantitatively determining whether or not the refrigerant amount is properly sealed, there is a method of detecting the liquid level of a liquid refrigerant stored in a tank such as a liquid receiver or an accumulator. As described in Japanese Patent Application Laid-Open No. 3-186170, an apparatus used for this determination is to measure the liquid level of a refrigerant in a receiver provided between a condenser and an evaporator of a refrigeration cycle by using a capacitance sensor. And the like, and detects the amount of the refrigerant required in the refrigeration cycle, compares the value with the value in the case of the required amount of the refrigerant, quantitatively calculates the amount of the enclosed refrigerant, and displays the amount.

[0005]

However, in the above-described apparatus for judging the amount of refrigerant, the case where the amount of refrigerant enclosed in the air conditioner is extremely small is not taken into consideration. .

[0006] First, a sight glass for visually observing the flow of the refrigerant inside the pipe is provided in a pipe section connecting the receiver and the pressure reducing device as a refrigerant quantity judging apparatus. Since it is determined whether or not there is liquid refrigerant at the tip of the pipe through which the refrigerant is introduced or discharged from the liquid container, it is not possible to quantitatively grasp the excess or deficiency of the amount of refrigerant enclosed in the air conditioner. However, there is a problem that it is impossible to determine how small the amount of refrigerant is, even if the amount is small.

When the amount of the refrigerant is determined by detecting the liquid level of the liquid refrigerant stored in a tank such as a liquid receiver or an accumulator, the liquid level in the tank such as the liquid receiver or the accumulator is determined. In the case of the amount of refrigerant that can change, the amount of refrigerant enclosed can be quantitatively grasped, but the amount of refrigerant in which the liquid level in the tank does not change, such as when the amount of refrigerant becomes extremely small In the case of, there is no correlation between the amount of refrigerant sealed in the air conditioner and the liquid level in the tank, and the liquid level is always constant regardless of the amount of refrigerant. There is a problem that it is not possible to quantitatively grasp the excess or deficiency of the amount of the enclosed refrigerant.

Further, when the amount of refrigerant sealed in the air conditioner is adjusted to an appropriate amount, when the amount of refrigerant is extremely small, the above-described refrigerant amount determination device can quantitatively grasp the excess or deficiency. Therefore, it is unknown how much refrigerant should be added. That is, as a method of adjusting the amount of refrigerant, when the amount of refrigerant to be additionally charged at one time is small, the amount of refrigerant after adjustment does not become excessively large, but there is a problem that the time for filling is long. In addition, when the amount of refrigerant to be additionally charged at one time is increased, the time for charging is shortened, but the amount of refrigerant after adjustment may be extremely large. However, there is a problem that the adjustment time of the refrigerant amount becomes long.

The present invention has been made to solve such a conventional technical problem, and even when the amount of refrigerant in an air conditioner is extremely small, it is quantitatively grasped and the amount of refrigerant is adjusted to an appropriate amount. To provide a refrigerant amount adjustment method capable of shortening the time required to perform the operation, a refrigerant amount determination device that quantitatively grasps the refrigerant amount in the air conditioner for refrigerant adjustment, and an air conditioner including the refrigerant amount determination device. With the goal.

[0010]

In order to achieve the above object, a refrigerant amount adjusting method according to the present invention comprises at least one outdoor unit and at least one indoor unit, and is installed in the outdoor unit. The compressor, outdoor heat exchanger, decompression device and receiver, the decompression device installed in the indoor unit, and the indoor heat exchanger are connected in order to adjust the refrigerant amount of the air conditioner that forms the refrigeration cycle to the appropriate amount. In the method of adjusting the amount of refrigerant, the air conditioner is cooled, the refrigerant flowing out of the receiver is supercooled, and the temperature and pressure of the refrigerant discharged from the compressor, the opening degree of the indoor expansion valve and the indoor air temperature are determined. Calculate the ratio of the amount of refrigerant sealed in the air conditioner to the appropriate amount, determine the amount of refrigerant to be added and sealed from this ratio, perform primary addition, and after the primary addition, the receiver The refrigerant flowing out of the pump is in a gas-liquid two-phase state Performs secondary Add Add predetermined amount of refrigerant, the refrigerant flowing out from the liquid receiver, characterized in that the repeating secondary Add to a liquid single-phase state.

In the method for adjusting the amount of refrigerant of the present invention, it is preferable that the amount of refrigerant added in the first order is determined so that the amount of refrigerant sealed in the air conditioner after the first addition is smaller than the calculated appropriate amount. Accordingly, the refrigerant amount can be easily adjusted to an appropriate amount by the secondary addition without excessive addition.

According to another aspect of the present invention, there is provided a refrigerant amount determining apparatus including at least one outdoor unit and at least one indoor unit, wherein a compressor installed in the outdoor unit and an outdoor unit are disposed. In order to adjust the amount of refrigerant in the air conditioner forming the refrigeration cycle by connecting the heat exchanger, decompression device and liquid receiver, the decompression device installed in the indoor unit, and the indoor heat exchanger in order with piping, In the refrigerant amount determination device used, based on the temperature and pressure of the refrigerant discharged from the compressor during the cooling operation, the opening degree of the indoor expansion valve, and the indoor air temperature, the amount of the refrigerant sealed in the air conditioner is determined based on an appropriate amount. An enclosure ratio determination device that calculates whether the ratio is in the ratio, a cooling unit that supercools the refrigerant flowing out of the liquid receiver, and a refrigerant that observes whether the supercooled refrigerant state is a gas-liquid two-phase state or a liquid phase Appropriate amount of flow state monitoring means Characterized in that it consists of a constant unit.

In the refrigerant amount judging device according to the present invention, it is preferable to use a sight glass having a glass that transmits light on one surface of a flow path through which the refrigerant flows or on both opposing surfaces as the refrigerant flow state monitoring means. Further, an air conditioner of the present invention is achieved by an air conditioner provided with the above refrigerant amount determination device.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to FIGS. FIG. 1 is a configuration diagram of a refrigeration cycle of a multi-room air conditioner equipped with the refrigerant amount determination device of the present invention. This air conditioner has a configuration in which a plurality of indoor units are connected to one outdoor unit via a connection pipe and a distributor. The outdoor unit is a compressor 1, a four-way valve 2,
As shown in FIG. 1, the outdoor heat exchanger 3, the outdoor expansion valve 4, the liquid receiver 5, the cooling device 6, the sight glass 7, and the accumulator 10 are connected by piping as shown in FIG. Each indoor unit has a configuration as shown in FIG. 1 which has each refrigeration cycle device of each indoor expansion valve 8a, 8b and each indoor heat exchanger 9a, 9b. During the cooling operation, the refrigerant flows from the compressor 1 in order,
Four-way valve 2, outdoor heat exchanger 3, outdoor expansion valve 4, liquid receiver 5,
Cooling device 6, sight glass 7, each indoor expansion valve 8a, 8
b, circulates through the indoor heat exchangers 9a and 9b, the four-way valve 2 and the accumulator 10 to return to the compressor 1.

In the outdoor unit and each indoor unit, control of the outdoor expansion valve 4 and each of the indoor expansion valves 8a and 8b is carried out in order to efficiently operate the multi-room air conditioner, and the indoor unit is sealed in the air conditioner. Various sensors necessary for determining the amount of refrigerant being provided are provided. That is, the outdoor unit includes a discharge temperature detector 11 (for example, a thermistor) and a discharge pressure detector 12 (for example, a pressure sensor) that detect the temperature and pressure of the refrigerant discharged from the compressor 1. It is provided in. On the other hand, each indoor unit has an indoor temperature detector 13a that detects the temperature of air flowing into each of the indoor heat exchangers 9a and 9b.
13b is provided in the passage of the air flowing into each of the indoor heat exchangers 9a and 9b. The opening degree of each of the outdoor expansion valve 4 and each of the indoor expansion valves 8a and 8b is also detected.

Output signals of various sensors provided in the outdoor unit and each indoor unit and the indoor expansion valves 8a, 8
The opening degree information b is taken into the memory 14. The memory 14 is connected to the arithmetic unit 15 so as to enable one-sided communication or two-sided communication, and further connected to a display unit 16 so that the result of the arithmetic unit 15 can be output. Here, the refrigerant amount determination device according to the present invention, the ratio of the amount of refrigerant enclosed in the air conditioner to an appropriate amount of refrigerant that is a refrigerant amount that can normally operate the air conditioner And a cooling device 6 for cooling the refrigerant flowing out of the receiver 6 and observing whether the cooled refrigerant is in a gas-liquid two-phase state or a liquid single-phase state. An appropriate amount determination device comprising a sight glass 7 for
It is composed of The enclosing ratio determination device and the appropriate amount determination device will be described later in detail.

In the above-described multi-room air conditioner,
During the heating operation, the refrigerant flows in the direction indicated by the solid line to warm the room. That is, the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is sent from the four-way valve 2 to the indoor heat exchangers 9a and 9b via the connection pipe and condensed to become liquid refrigerant. , 9b to radiate heat to the air passing therethrough to heat the room. The condensed and liquefied refrigerant passes through the indoor expansion valves 8 a and 8 b and the connection pipe, passes through the liquid receiver 5, is reduced to a predetermined pressure by the outdoor expansion valve 4, is sent to the outdoor heat exchanger 3, and is sent to the outdoor heat exchanger 3. Absorbs heat from the air passing therethrough and evaporates, passes through the four-way valve 2 and the accumulator 10, and
And compressed by the compressor 1 again.

On the other hand, during the cooling operation, the refrigerant is cooled in the room by flowing in the direction shown by the broken line. That is, the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 is sent to the outdoor heat exchanger 3 via the four-way valve 2 and radiates heat to the air passing through the outdoor heat exchanger 3 to condense and liquefy. The condensed and liquefied refrigerant is sent to the indoor expansion valves 8a, 8b via the outdoor expansion valve 4, the liquid receiver 5, and the connection pipe, and the indoor expansion valves 8a, 8b
The pressure is reduced to a predetermined pressure by each of the indoor heat exchangers 9.
a, 9b, when each of the indoor heat exchangers 9a,
The room is cooled by absorbing heat from the air passing through 9b. The evaporated refrigerant returns to the compressor 1 through the four-way valve 2 and the accumulator 10, and is compressed again by the compressor 1.

The multi-room air conditioner is filled with a predetermined amount of refrigerant (a proper amount of refrigerant) capable of normal operation, and unnecessary excess refrigerant in the above-described refrigerant circulation is discharged outside the room. It is stored as a liquid refrigerant in a liquid receiver 5 installed in the machine.

Generally, as a method of charging a refrigerant in a multi-room air conditioner, the length of a pipe connecting an outdoor unit and a plurality of indoor units located at positions remote from the outdoor unit, the length of the indoor unit, and the like. Since the number of units differs at each construction site, only the amount of refrigerant required for the outdoor unit is enclosed in the outdoor unit at the time of shipment, and after the installation is completed, the refrigerant required for the connection piping and indoor unit is installed in the multi-room air conditioner A method of additionally enclosing on site according to the state is adopted. Here, when the total amount of refrigerant sealed in the multi-room air conditioner is within an appropriate range, the air conditioner exhibits the performance as specified and does not cause a failure. However, if the total amount of the enclosed refrigerant is excessive or insufficient beyond a certain range than an appropriate amount, not only the predetermined performance cannot be exhibited, but if the amount of the refrigerant is insufficient, the temperature at the compressor discharge side rises. If the motor winding is deteriorated or the amount of refrigerant is excessive, the liquid refrigerant returns to the compressor suction side and compresses the liquid refrigerant at the time of compression, thereby imposing a large load on the compressor bearing, shaft, motor, etc. , Which may lead to a failure that may cause damage. For this reason, in order to ensure the reliability as well as the performance of the air conditioner, it is necessary to accurately fill a refrigerant amount suitable for the construction state such as the length of the connection pipe of the air conditioner and the number of indoor units. However, in the on-site filling operation, the filling operation is incorrect due to inadequate filling operation, failure of the measuring instrument or operation error, etc. Due to an error in the calculation of the amount or the like, an appropriate amount of refrigerant cannot always be filled accurately. Here, even if a mistake during the filling operation as described above occurs, if it is possible to determine whether or not the amount of refrigerant filled in the air conditioner is appropriate, it is possible to ensure the performance and reliability of the air conditioner. it can.

[0021] A refrigerant amount judging device according to the present invention comprises: an enclosing ratio judging device for calculating a ratio of an enclosing refrigerant amount sealed in an air conditioner to an appropriate amount;
And an appropriate amount determining device for determining whether the amount of the charged refrigerant is appropriate. As shown in FIG. 1, the appropriate amount determination device is provided on one side or in the middle of a pipe connecting the receiver 5 and each of the indoor expansion valves 8 a and 8 b in order to observe the flow state of the refrigerant flowing out of the receiver 5. A sight glass 7 made of a transparent wall is provided on the opposite side, and a sight glass 7 and a receiver 5 are provided.
Is provided with a cooling device 6 for cooling the piping connecting the. The cooling device 6 includes the four-way valve 2 and the accumulator 10
Is connected to the pipe connecting the sight glass 7 and the liquid receiver 5. The contact portion between these two pipes is brazed in order to improve the efficiency of heat transfer, and the periphery thereof is covered with a heat insulating material.

Next, the determination of the refrigerant amount by the appropriate amount determination device will be described with reference to FIGS. FIG. 2 is a Mollier diagram showing a cycle operation state when the amount of refrigerant enclosed in the refrigeration cycle is small and when it is appropriate. In the two operating states shown in FIG. 2, the solid line shows the case where the amount of the enclosed refrigerant is appropriate, and the broken line shows the case where the amount of the enclosed refrigerant is small.

When judging the amount of refrigerant by the appropriate amount judging device, all the connected indoor units are operated with the operation mode of the air conditioner as cooling. The operation state of the refrigeration cycle at the time of judging the refrigerant amount is as shown in FIG. 2, when the enclosed refrigerant amount is appropriate, the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 becomes point b, and the four-way valve 2 through the outdoor heat exchanger 3
And radiates heat to the air passing through the outdoor heat exchanger 3 and c
Point, and the pressure is reduced through the outdoor expansion valve 4 to point d,
It flows into the receiver 5. The refrigerant in the saturated liquid state flowing out of the receiver 5 is cooled by the cooling device 6 to the point e, passes through the sight glass 7 and the connecting pipe, and is decompressed by the indoor expansion valves 8a and 8b to the point f to become the indoor heat exchanger 9a , 9b, and absorbs heat from the air passing through the indoor heat exchangers 9a, 9b to become point a, where it is sucked into the compressor 1 suction side.

On the other hand, when the amount of the enclosed refrigerant is smaller than the proper case, the amount of the refrigerant in the refrigeration cycle is small, so that the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 has a higher pressure than the proper case. Point b ′, which is sent to the outdoor heat exchanger 3 via the four-way valve 2 and radiates heat to the air passing through the outdoor heat exchanger 3, and the temperature difference between the air and the heat exchanger 3 is smaller than when the temperature is appropriate. Therefore, the pressure becomes point c ′ in the gas-liquid two-phase state, passes through the outdoor expansion valve 4 and is reduced to point d ′, and flows into the liquid receiver 5. The refrigerant in the gas-liquid two-phase state flowing out of the receiver 5 is cooled by the cooling device 6 to point e ′, and the sight glass 7,
After passing through the connection pipe, the pressure is reduced by the indoor expansion valves 8a and 8b to point f ', which is sent to the indoor heat exchangers 9a and 9b, where it absorbs heat from the air passing through the indoor heat exchangers 9a and 9b to point a' and compresses. Machine 1 is sucked into the suction side.

The method for judging whether the amount of the filled refrigerant is appropriate or not by the appropriate amount determining device is based on the following principle. That is, when the amount of the enclosed refrigerant is proper, the refrigerant flowing through the refrigerant pipe 17 and flowing into the receiver 5 through the refrigerant introduction pipe 19 as shown in FIGS. 2 and 3 is in a saturated liquid state. Sufficient liquid refrigerant is stored in the liquid receiver 5, and the refrigerant flowing out of the refrigerant outlet pipe 20 is also in a saturated liquid state. The refrigerant in the saturated liquid state is cooled by the cooling device 6 through the refrigerant pipe 18, and the refrigerant in the supercooled liquid state flows into the sight glass 7. .

On the other hand, when the amount of the enclosed refrigerant is smaller than an appropriate amount, as shown in FIGS.
, The refrigerant flowing into the receiver 5 through the refrigerant introduction pipe 19 is in a gas-liquid two-phase state, so that sufficient liquid refrigerant is not stored in the receiver 5 and flows out of the refrigerant outlet pipe 20. The refrigerant that flows is also in a gas-liquid two-phase state. The refrigerant in the gas-liquid two-phase state is cooled by the cooling device 6 via the refrigerant pipe 18 even when the sight glass 7 is cooled.
The gas-liquid two-phase state refrigerant having bubbles in the liquid flows into the sight glass 7, and the gas-liquid two-phase state refrigerant is observed in the sight glass 7. In this way, by observing the sight glass 7, which is an appropriate amount determination device, it is possible to determine whether the amount of refrigerant sealed in the air conditioner is appropriate or small.

Here, if the appropriate amount determining device determines that the amount of the refrigerant is small, an operation of adding the refrigerant to the appropriate amount of the refrigerant occurs so that the air conditioner can operate normally. The proper amount of refrigerant means that it is sufficient to add the refrigerant until the refrigerant in the sight glass 7 becomes a liquid single-phase state, but it is difficult to quantitatively grasp how small the amount is in the sight glass 7. It is. Therefore, when the amount of the refrigerant sealed in the air conditioner is adjusted to an appropriate amount by using a method such as observing the sight glass 7 little by little, the existing amount of the refrigerant is considerably smaller than the appropriate amount. In this case, the adjustment time of the refrigerant amount becomes very long.

Therefore, the refrigerant amount judging device of the present invention is provided with an enclosing ratio judging device for quantitatively judging how small the amount of refrigerant sealed in the air conditioner is compared to an appropriate amount of refrigerant. ing. As shown in FIG. 1, the filling ratio determination device includes a discharge temperature detector 11 for detecting a refrigerant temperature on the discharge side of the compressor 1, a discharge pressure detector 12 for detecting a refrigerant pressure on the compressor discharge side, Indoor temperature detectors 13a and 13b for detecting the temperature of the air (fluid to be cooled) flowing into the exchangers 9a and 9b, the opening degree detectors of the indoor expansion valves 8a and 8b, and the detectors 11, 12, and 13a , 13b and a memory 14 for storing opening degree information of each indoor expansion valve 8a, 8b.
And an arithmetic unit 15 connected to the memory 14 so as to enable one-sided communication or two-sided communication.
Display device 16 connected to output the result of
And is composed of

FIG. 5 shows a case where the degree of superheat of the discharge gas, the average opening degree of each of the indoor expansion valves 8a and 8b, and the indoor temperature are used as factors for the determination by the charging ratio determination device. FIG. 4 is a diagram showing how the ratios are related. In FIG. 5A, the horizontal axis represents the encapsulation ratio with respect to the proper refrigerant amount, the vertical axis represents the degree of superheat of the discharge gas, and in FIG. The average opening degree of the indoor expansion valve is shown. 5A and 5B, broken lines show the relationship between the average opening degree of the indoor expansion valve and the refrigerant charging ratio and the relationship between the superheat degree of the discharge gas and the refrigerant charging ratio when the indoor temperature is high, and the dotted line shows the indoor temperature. The solid line indicates the respective relationship when the temperature is low, and the solid line indicates the respective relationship when the room temperature is between the broken line and the dotted line.

The filling ratio β indicates the case where the amount of refrigerant filled in the air conditioner is appropriate. The average opening degree of the indoor expansion valve and the superheat degree of the discharged gas are substantially constant values P1 and DT.
1 is shown.

When the filling ratio becomes larger than the appropriate value β, until the liquid refrigerant is stored in the receiver 5 and overflows, the average opening of each indoor expansion valve is required so that the receiver 5 functions as a buffer tank. The degree of superheat and the degree of superheat of the discharged gas do not change.
Since the liquid refrigerant in the indoor heat exchangers 9a and 9b functioning as evaporators increases and the discharge temperature decreases, the indoor expansion valves 8a and 8b are throttled to maintain the discharge temperature. further,
Since the amount of liquid refrigerant in the outdoor heat exchanger 3 functioning as a condenser also increases, the discharge pressure increases, and when the discharge temperature is controlled to be constant, the degree of superheat of the discharge gas also decreases.

On the other hand, when the filling ratio is smaller than the appropriate value β, the refrigerant in the gas-liquid two-phase state flows into and out of the receiver 5 as shown by the broken line in the Mollier diagram shown in FIG. The resistance of each indoor expansion valve 8a, 8b increases, and the opening degree of each indoor expansion valve 8a, 8b increases to secure the same flow rate. The average opening degree becomes P2 (full open), the discharge temperature cannot be controlled, the discharge temperature starts to increase, and the discharge gas superheat degree increases as the filling ratio decreases.

Furthermore, the superheat degree of the discharge gas and the average opening degree of each indoor expansion valve with respect to the enclosing ratio are such that when the indoor temperature is low, the suction pressure is reduced, so that the refrigerant circulation amount is reduced and the indoor heat exchangers 9a, 9b Since the evaporation performance is reduced, each indoor expansion valve 8
The values of the average opening degree of the a and 8b and the superheat degree of the discharge gas become small, and when the room temperature is high, the suction pressure increases and the evaporation performance in the indoor heat exchangers 9a and 9b is improved, so that each indoor expansion valve 8a, The value of the average opening degree and the degree of superheat of the discharge gas of FIG.

As described above, by using the degree of superheat of the discharge gas, the average opening degree of each indoor expansion valve, and the indoor temperature, it is possible to determine the ratio of the amount of refrigerant charged in the air conditioner to the proper case. .

Next, a method of adjusting the amount of refrigerant sealed in the air-conditioned air using the refrigerant amount judgment device of the present invention comprising the above-described appropriate amount judgment device and enclosing ratio judgment device will be described with reference to FIGS. This will be described with reference to FIG.

FIGS. 6 and 7 show flowcharts of the refrigerant amount determination and adjustment for adjusting the refrigerant amount in the air conditioner to an appropriate amount using the refrigerant amount determination device of the present invention. First, all the indoor units are started in the cooling operation, and after waiting for a predetermined time ΔT1, the intake air temperatures Ta1, Ta2 of each indoor unit, the opening degrees PL1, PL2 of each indoor expansion valve, the discharge pressure Pd, and the discharge temperature Td are changed to various temperatures. The value is detected by the sensor and the pressure sensor, and the detected value is transmitted to the memory 14. The memory 14 calculates the discharge pressure equivalent saturation temperature Tds from the discharge pressure Pd, and calculates the discharge gas superheat degree TdSH from the calculated discharge pressure equivalent saturation temperature Tds and discharge temperature Td. Next, the suction air temperature Ta1, Ta2 of each indoor unit, the opening degree PL1, of each indoor expansion valve,
According to the relationship diagram shown in FIG. 5 stored in advance in the memory from PL2 and the calculated discharge gas superheat degree TdSH, the ratio Xr of the refrigerant sealed in the air conditioner is determined.
Is calculated. Next, an additional refrigerant amount Wr1 is calculated from the calculated charging rate Xr, and the additional refrigerant amount Wr1 is charged in the air conditioner. next,
After waiting for a predetermined time ΔT2, the refrigerant flow state of the sight glass, which is the appropriate amount determination device, is observed, and if the liquid is a single phase, it is determined that the appropriate amount of refrigerant is sealed, and the refrigerant amount determination and refrigerant amount adjustment are terminated. If it is not a liquid single phase, that is, if it is in a gas-liquid two-phase state, the operation of enclosing a predetermined amount of refrigerant in the air conditioner and observing the sight glass is repeated until the inside of the sight glass becomes a liquid single-phase state. When the is in the liquid single phase state, the determination of the refrigerant amount and the adjustment of the refrigerant amount are terminated.

Here, the additional refrigerant amount Wr1 is set to be smaller than an appropriate refrigerant amount even after additional filling. In addition, regarding the calculation of the encapsulation ratio Xr, since the numerical value is slightly different depending on the construction state and operation state of the air conditioner, the production of each component device, and the variation of the control device, the judgment value of the encapsulation ratio is made stepwise. This can eliminate the determination error due to the above-described variation.

Next, a method of setting the additional refrigerant amount Wr1 will be described. FIG. 8 is a diagram showing the state of determination of the filling ratio and the additional refrigerant amount Wr.
FIG. 4 is a relationship diagram showing the ratio of the amount of refrigerant enclosed in the air conditioner to the appropriate value (β) after the primary enclosure of 1 is performed. Regarding the judgment value of the encapsulation ratio, the numerical value differs slightly depending on the construction condition and operation state of the air conditioner, the production of each component device, and the variation of the control device, etc. And For example, the encapsulation ratio is 20% or less, 20 to 40%, 40 to 6
The determination is made in five steps within a 20% range, such as 0%, 60 to 80%, and 80% or more. The additional refrigerant amount Wr1 (the hatched portion in the figure) is an amount (35) at which the encapsulation ratio after adding the refrigerant to the maximum value of the determined stage (for example, 60% in the third stage of 40 to 60%) becomes 95%. % Increase). As a result, the judgment is the third stage, and the actual enclosing ratio is the lowest of 40%.
, It is possible to set the encapsulation ratio after the primary additional encapsulation to 75% of the appropriate amount. Initial inclusion ratio is 50
In the case of%, it becomes 85% after adding the additional refrigerant amount. As a result, the number of times of the secondary additional encapsulation, that is, the number of repetitive operations of enclosing a predetermined amount of refrigerant in the air conditioner and observing the sight glass 7 until the inside of the sight glass 7 becomes a liquid single phase state can be reduced, and an appropriate The time until the amount of the refrigerant is reduced can be reduced.

Here, by making the enclosing ratio judgment value determined stepwise finer, the enclosing ratio after enclosing the additional refrigerant amount can be made closer to the proper refrigerant amount, and the time until the proper refrigerant amount is reached. Can be shortened.

As described above, by using the refrigerant amount judging device comprising the proper amount judging device and the filling ratio judging device of the present invention, the amount of refrigerant sealed in the air conditioner at the time of judging the amount of refrigerant is much more than when the amount of refrigerant is proper. Even in the case of a small amount, the amount of additional refrigerant is determined from the result of the charging ratio determination device and filled, thereby reducing the time required to adjust the amount of refrigerant to an appropriate amount.

Here, in the present invention, the sight glass is used as the appropriate amount determining device, but similarly, a capacitance sensor, an ultrasonic sensor, an optical sensor, or the like that can determine a liquid single-phase state and a gas-liquid two-phase state can be used. It has the same effect and does not depart from the scope of the present invention.

Further, in the present invention, the superheat degree of the discharge gas, the average opening degree of each indoor expansion valve, and each indoor temperature are used as factors used in the filling ratio determination apparatus, but similarly, the ratio changes with the change of the filling ratio. The same effect can be obtained by combining a plurality of values of the operating condition of the air conditioner, such as temperature, pressure, load current of the compressor, opening degree of the expansion valve, air flow, etc., and this does not depart from the scope of the present invention.

Further, by outputting the value of the charging ratio determined by the charging ratio determination device to the display device, it is possible to constantly monitor the amount of the refrigerant sealed in the air conditioner. And it is possible to prevent the occurrence of a failure due to the amount of refrigerant.

[0044]

According to the present invention, a refrigerant amount adjusting method is provided for adjusting the amount of refrigerant enclosed in an air conditioner including at least one outdoor unit and at least one indoor unit to an appropriate amount. The air conditioner cools down and supercools the refrigerant flowing out of the receiver, and is filled in the air conditioner based on the temperature and pressure of the refrigerant discharged from the compressor, the opening degree of the indoor expansion valve, and the indoor air temperature. Calculate the ratio of the refrigerant amount to the appropriate amount, determine the amount of refrigerant to be added and sealed from this ratio, perform primary addition, and the refrigerant flowing out of the receiver after primary addition is gas-liquid. In the case of a two-phase state, a secondary addition to add a predetermined amount of refrigerant is performed, and the method of repeating the secondary addition until the liquid flowing out of the receiver becomes a single-phase liquid state indicating that the refrigerant is an appropriate amount is adopted. , The amount of refrigerant enclosed in the air conditioner when adjusting the amount of refrigerant Even if very less than the proper amount,
It is possible to reduce the time required to adjust the refrigerant amount to an appropriate amount, and to accurately adjust the refrigerant amount to an appropriate amount. In addition, since it is possible to surely adjust the amount of the refrigerant to an appropriate amount, it is possible to prevent the occurrence of a failure due to a shortage or an excessive amount of the refrigerant. When adjusting the amount of refrigerant, the air conditioner is operated for cooling, so that the liquid refrigerant supercooled by the cooling device passes through the connection pipe. Since the refrigerant in the connection pipe having a large change can be a stable liquid refrigerant, it is possible to reliably adjust the amount of the refrigerant.

Also, the amount of the refrigerant added in the first order is determined after the first addition.
By determining the amount of the refrigerant in the air conditioner to be smaller than the appropriate amount, it is possible to reliably adjust the amount of the refrigerant to an accurate amount without overfilling even if an error occurs in the filling ratio determination device.

As an appropriate amount judging device constituting the refrigerant amount judging device of the present invention, a cooling device and a refrigerant flowing state in a pipe on a refrigerant outflow side of a receiver are used to judge whether a refrigerant is in a single liquid phase or a gas-liquid two phase. For the refrigerant flow state monitoring means for the
Since the refrigerant flowing out of the receiver can be supercooled by the cooling device, it is possible to prevent a detection error in the flow state monitoring means due to a pressure loss generated when the refrigerant passes through a pipe or the like. The amount can be adjusted. And by using a sight glass made of glass that allows light to pass through on one or both sides as refrigerant flow state monitoring means,
Not only can a reliable judgment be made by direct visual observation without an electric signal or the like, but also a simple structure can be used, so that the cost can be reduced in comparison with an object judged using an electric signal or the like. effective.

Further, as an enclosing ratio judging device which constitutes the refrigerant amount judging device of the present invention, the air conditioner can be installed in the air conditioner based on the operating conditions such as the temperature and pressure of the refrigerant discharged from the compressor, the opening degree of the expansion valve and the room air temperature. By calculating the charging ratio of the charged refrigerant amount, the charging ratio can be accurately determined from the operating state of the air conditioner that responds sensitively to a change in the charging ratio.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a refrigeration cycle of a multi-room air conditioner including a refrigerant amount determination device of the present invention.

FIG. 2 is a Mollier chart showing an operation state of a refrigeration cycle when the amount of refrigerant sealed in the air conditioner is appropriate and when the amount is less than the appropriate amount.

FIG. 3 is a diagram showing that a refrigerant state in a sight glass is a single-phase liquid when a refrigerant amount sealed in an air conditioner is proper.

FIG. 4 is a diagram showing that the refrigerant state in the sight glass is a gas-liquid two-phase when the amount of refrigerant sealed in the air conditioner is smaller than an appropriate amount.

FIG. 5 shows a relationship between a refrigerant charging ratio, an average opening degree of each indoor expansion valve and a room temperature, and a relationship between a refrigerant charging ratio and a discharge gas superheat degree used in the refrigerant amount adjusting method according to one embodiment of the present invention. FIG.

FIG. 6 is a flowchart (part 1) illustrating a refrigerant amount adjusting method according to an embodiment of the present invention.

FIG. 7 is a flowchart (part 2) illustrating a refrigerant amount adjusting method according to an embodiment of the present invention.

FIG. 8 is a diagram showing the ratio of the amount of the refrigerant charged into the air conditioner to the appropriate value at the time of determining the charging ratio and after the primary addition in the refrigerant amount adjusting method according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Compressor 2 ... Four-way valve 3 ... Outdoor heat exchanger 4 ... Outdoor expansion valve 5 ... Liquid receiver 6 ... Cooling device 7 ... Sight glass 8a, 8b ... Indoor expansion valve 9a, 9b ... Indoor heat exchanger 10 ... Accumulator DESCRIPTION OF SYMBOLS 11 ... Discharge temperature detector 12 ... Discharge pressure detector 13a, 13b ... Indoor temperature detector 14 ... Memory 15 ... Calculation device 16 ... Display device 17, 18 ... Refrigerant pipe 19 ... Refrigerant introduction pipe 20 ... Refrigerant discharge pipe

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Shinichiro Yamada 390 Muramatsu, Shimizu-shi, Shizuoka Hitachi Air Conditioning Systems Co., Ltd. Shimizu Production Headquarters

Claims (5)

[Claims] At least one outdoor unit and at least one outdoor unit
Composed of two indoor units, a compressor installed in the outdoor unit, an outdoor heat exchanger, a decompression device and a receiver, a decompression device installed in the indoor unit, an indoor heat exchanger connected in order In a refrigerant amount adjusting method for adjusting an amount of refrigerant of an air conditioner forming a refrigeration cycle to an appropriate amount, a cooling operation of the air conditioner is performed to supercool a refrigerant flowing out of the liquid receiver, and the compressor discharges the refrigerant. Based on the temperature and pressure of the refrigerant, the opening degree of the indoor expansion valve and the indoor air temperature, calculate the ratio of the amount of the refrigerant sealed in the air conditioner to an appropriate amount, and calculate the ratio from the ratio. The amount of refrigerant to be added and sealed is determined and the primary addition is performed. After the primary addition, when the refrigerant flowing out of the liquid receiver is in a gas-liquid two-phase state, a secondary addition is performed to add a predetermined amount of the refrigerant, and the reception is performed. Until the refrigerant flowing out of the liquid Refrigerant amount adjustment method characterized by repeating the secondary added. 2. The refrigerant amount adjusting method according to claim 1, wherein the amount of the first additional refrigerant is determined so that the amount of the refrigerant sealed in the air conditioner after the first addition becomes smaller than the appropriate amount. . 3. At least one outdoor unit and at least one outdoor unit
And an indoor unit, and a compressor, an outdoor heat exchanger, a decompression device and a receiver installed in the outdoor unit, a decompression device installed in the indoor unit, and an indoor heat exchanger are sequentially connected by piping. In the refrigerant amount determination device used to adjust the refrigerant amount in the air conditioner forming a refrigeration cycle to an appropriate amount,
Based on the temperature and pressure of the refrigerant discharged from the compressor during the cooling operation, the opening degree of the indoor expansion valve, and the indoor air temperature, the ratio of the refrigerant enclosed in the air conditioner to an appropriate amount is calculated. An enclosure ratio determination device, cooling means for supercooling the refrigerant flowing out of the liquid receiver, and refrigerant flow state monitoring means for observing whether the supercooled refrigerant state is a gas-liquid two-phase state or a liquid phase. A refrigerant amount judging device comprising an appropriate amount judging device. 4. The refrigerant amount judging device according to claim 3, wherein the refrigerant flow state monitoring means is a sight glass having a glass that transmits light on one surface or on both opposing surfaces of the flow path through which the refrigerant flows. . 5. An air conditioner comprising the refrigerant amount judging device according to claim 3 or 4.