JP4110276B2 - Refrigerant filling apparatus and refrigerant filling method - Google Patents

Description

  The present invention relates to an air conditioner and a refrigerant filling apparatus that fills the air conditioner with a refrigerant, and is particularly suitable for an apparatus that automatically fills an appropriate refrigerant with respect to the installation state of the air conditioner.

In the case of a multi-room type air conditioner, in which a plurality of indoor units are connected, among the air conditioners, there are a wide variety of installation conditions for indoor units and outdoor units due to the structure and management of the building. It is impossible to ship with the total amount of refrigerant. For this reason, the work which always carries out additional filling of a refrigerant | coolant arises at the construction site.
Conventionally, based on the capacity of the outdoor unit and the indoor unit, the length of the connecting pipe connecting the outdoor unit and the indoor unit, and the height position information of the indoor unit with respect to the outdoor unit, Additional refrigerant determined for the connecting pipe diameter determined for each unit capacity, the additional refrigerant charge per unit length of the pipe diameter and the indoor unit capacity, and the height of the indoor unit relative to the outdoor unit It is known to calculate an additional refrigerant filling amount suitable for the construction situation of the multi-chamber air conditioner from the filling amount correction coefficient, and to fill the refrigerant while measuring the refrigerant cylinder with a measuring instrument or the like. It is described in.
In addition, a bypass circuit that connects the compressor discharge side pipe and the suction side pipe of the refrigeration cycle is provided, and the bypass circuit stores a refrigerant reservoir for storing surplus refrigerant and a circuit that flows into the refrigerant reservoir from the discharge side pipe; An open / close valve is provided for each refrigerant circuit that flows out from the refrigerant reservoir to the suction side pipe, and a refrigerant amount determination unit that determines whether or not the amount of refrigerant in the refrigeration cycle is appropriate is provided. Is detected, the on-off valve of the circuit bypassing from the refrigerant reservoir to the compressor suction side pipe is opened, and the refrigerant in the air conditioner is reduced by releasing the refrigerant in the refrigerant reservoir to the compressor suction side. The adjustment is described in Patent Document 2.

Japanese Patent Laid-Open No. 11-63745 (FIG. 8)

Japanese Patent Laid-Open No. 9-273739 (FIG. 1)

In the above-mentioned Patent Document 1, the value of the additional refrigerant charging amount is calculated by the additional refrigerant amount calculating means. However, it is the operator who fills the additional refrigerant amount, and the refrigerant is insufficient due to the occurrence of human error. There is a risk of a state or excessive refrigerant state. Further, when a refrigerant cylinder is connected to the low-pressure side service port of the refrigeration cycle and the refrigerant is charged, the liquid refrigerant easily returns to the compressor suction side, resulting in a compressor failure.
Moreover, in the thing of patent document 2, when adding a refrigerant | coolant additionally, since a refrigerant | coolant flows out from a refrigerant | coolant reservoir to the compressor suction side, a liquid refrigerant | coolant becomes easy to return to a compressor suction side, and there exists a possibility of causing a failure of a compressor. is there. Furthermore, even if the gas refrigerant is returned from the top of the refrigerant reservoir to the compressor suction side in order to prevent the liquid from returning to the compressor suction side, the mass of the gas refrigerant is so light that the adjustment of the refrigerant amount is significant. It takes time.

An object of the present invention is to provide a refrigerant charging device capable of ensuring the reliability of a refrigeration cycle by automatically adding additional refrigerant to an air conditioner so as to obtain an appropriate amount of refrigerant and suppressing liquid return to the compressor. It is to obtain a refrigerant charging method.

In order to achieve the above object, the present invention provides a refrigeration cycle in which an outdoor unit having a compressor, an outdoor heat exchanger, a pressure reducing device, and a liquid receiver, and an indoor unit having an indoor heat exchanger and a pressure reducing device are connected by piping. On the other hand, in the refrigerant filling device that fills the outdoor unit with a predetermined amount of refrigerant, or additionally fills the refrigerant, the subcooling heat exchanger having a subflow portion between the liquid receiver of the outdoor unit and the indoor unit. A main flow portion is disposed, one of the subflow portions is connected to a refrigerant cylinder via a refrigerant filling electromagnetic valve, and the other is connected to the suction side of the compressor, and the refrigerant filling electromagnetic wave is determined after the refrigeration cycle is determined to be stable. Open the valve to fill the refrigerant, and when the refrigerant supercooling degree on the outlet side of the main flow portion of the supercooling heat exchanger becomes equal to or higher than a preset value for proper refrigerant charging, closed so as to complete the refrigerant charging And it controls the opening and closing of the serial refrigerant charge solenoid valve.

Further, in the above, a bypass circuit is provided that bypasses between the inlet of the subflow portion and the refrigerant-filled solenoid valve from a pipe connecting the liquid receiver and the supercooling heat exchanger, and the bypass circuit It is desirable to provide a supercooling bypass expansion valve.
Further, in the above, a blocking valve is provided on the upstream side of the refrigerant charging solenoid valve, and a second bypass circuit is provided in which the refrigerant flows from between the refrigerant charging solenoid valve and the blocking valve to the outlet side of the main flow portion. It is desirable.

Further, in the above, the apparatus includes a discharge pressure sensor provided on the discharge side of the compressor, and a temperature thermistor provided on the outlet side of the main flow portion of the supercooling heat exchanger, and the pressure by the discharge pressure sensor calculating a Atsushi Kazu from the value, the calculated difference the refrigerant supercooling degree and to Rukoto the saturated temperature and the output value of the temperature thermistor is desirable.
Furthermore, in the above, it is preferable that the refrigerant superheating degree on the discharge side of the compressor is detected and the refrigeration cycle is controlled so that the refrigerant superheating degree becomes a predetermined value during the refrigerant filling.

Furthermore, the present invention provides a refrigerant to a refrigeration cycle in which an outdoor unit having a compressor, an outdoor heat exchanger, a decompression device, and a liquid receiver, and an indoor unit having an indoor heat exchanger and a decompression device are connected by piping. A refrigerant charging method for charging, wherein a main flow portion of a subcooling heat exchanger having a subflow portion is disposed between a liquid receiver of the outdoor unit and the indoor unit, and one of the subflow portions is a refrigerant charging electromagnetic A refrigerant cylinder is connected via a valve, and the other is connected to the suction side of the compressor . After the refrigeration cycle is determined to be stable, the refrigerant charging electromagnetic valve is opened to fill the refrigerant, and the supercooling heat exchanger Opening and closing the refrigerant charging solenoid valve so that the refrigerant charging solenoid valve is closed and the refrigerant charging is completed when the refrigerant supercooling degree on the outlet side of the main flow part becomes equal to or higher than a preset value for proper refrigerant charging. The refrigerant is charged while controlling .

According to the present invention, the main flow portion of the supercooling heat exchanger having the subflow portion is provided between the liquid receiver attached to the outdoor unit and the indoor unit, and one of the subflow portions has the refrigerant-filled electromagnetic valve. Since the other is connected to the refrigerant cylinder and the other side to the suction side of the compressor, the following effects can be obtained.
(A) When proper refrigerant charging is performed, after the refrigeration cycle is determined to be stable, the refrigerant filling solenoid valve is opened to fill the refrigerant, and the refrigerant subcooling degree on the outlet side of the main stream portion of the supercooling heat exchanger is preset. When the refrigerant charging operation is performed while controlling the opening and closing of the refrigerant charging electromagnetic valve so that the refrigerant charging is completed by closing the refrigerant charging electromagnetic valve when the value becomes equal to or greater than the value of Since the refrigerant can be additionally charged, the reliability of the refrigeration cycle can be ensured.
(B) Since the liquid refrigerant flowing out from the refrigerant cylinder is heated and gasified by the supercooling heat exchanger and filled, the liquid return to the compressor can be suppressed, so the reliability of the compressor during refrigerant filling is reliable. The sex can be further secured.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a refrigeration cycle system diagram of an air conditioner equipped with a refrigerant filling apparatus according to an embodiment of the present invention, in which an outdoor unit and an indoor unit are connected by a gas side connection pipe and a liquid side connection pipe. The outdoor unit is connected to the compressor 1, the four-way valve 2, the outdoor heat exchanger 7, the outdoor expansion valve 6, the liquid receiver 5, the accumulator 8, the gas blocking valve 10 connected to the gas side connection pipe, and the liquid side connection pipe. The liquid blocking valve 11 is connected by piping.
The discharge side piping of the compressor 1 is provided with a discharge pressure sensor 15 for detecting the pressure of the refrigerant gas discharged from the compressor and a discharge temperature thermistor 16 for detecting the temperature of the discharged refrigerant gas. And the output signal of the discharge temperature thermistor 16 are input to the discharge gas superheat degree calculating means 32, and the saturation temperature is calculated based on the signal of the discharge pressure sensor 15, and the difference between the discharge temperature thermistor 16 and the calculated saturation temperature is calculated. The discharge gas superheat degree is calculated by calculating.
Further, a supercooling heat exchanger 9 for supercooling the liquid refrigerant flowing out from the liquid receiver 5 is provided between the liquid receiver 5 and the liquid blocking valve 11. The subcooling heat exchanger 9 is provided with a main flow portion and a bypass portion, and is configured to exchange heat between the main flow portion and the bypass portion. The main flow part of the supercooling heat exchanger 9 is connected to one of the liquid receiver 5 and the liquid blocking valve 11, one of the bypass parts is connected to the inlet of the accumulator 8, and the other is connected to the pipe. The refrigerant cylinder 50 is connected to the refrigerant cylinder 50 via the refrigerant filling electromagnetic valve 14. Between the supercooling heat exchanger 9 and the liquid blocking valve 11, a supercooling heat exchanger outlet temperature thermistor 17 for detecting the temperature of the liquid refrigerant cooled by the supercooling heat exchanger 9 is provided. The output signals of the sensor 15 and the supercooling heat exchanger outlet temperature thermistor 17 are input to the supercooling degree calculation means 30, and the saturation temperature is calculated based on the signal of the discharge pressure sensor 15, and the calculated saturation temperature and supercooling heat are calculated. By calculating the difference between the values of the exchanger outlet temperature thermistor 17, the degree of supercooling at the outlet of the supercooling heat exchanger is calculated.
In the indoor unit, the indoor heat exchanger 3 and the indoor expansion valve 4 are connected by pipe, and the gas side service port 12 and the liquid side service port 13 are respectively connected to the gas side pipe and the liquid side pipe connecting the outdoor unit and the indoor unit. Is provided.
Further, the output signal of the discharge gas superheat degree calculation means 32 is connected to the drive circuit of the indoor expansion valve 4, and the output signal of the supercooling calculation means 30 is input to the refrigerant filling electromagnetic valve opening / closing means 31, and the refrigerant filling electromagnetic valve opening / closing means The output signal 31 is connected to the drive circuit of the refrigerant filling electromagnetic valve 14.

Next, the refrigerant filling method of the air conditioner will be described with reference to FIGS. FIG. 2 shows a refrigerant filling flowchart showing a refrigerant filling method by the refrigerant filling apparatus of the present invention. The outdoor unit is pre-filled with the minimum amount of refrigerant necessary for the outdoor unit, and after the outdoor unit and indoor unit are installed on site, the air and moisture in the gas side connection pipe, liquid side connection pipe, and indoor unit are removed. In order to remove it, a vacuum pump or the like is connected to the gas side service port 12 and the liquid side service port 13 to evacuate the inside of the pipe and the inside of the machine pipe. Next, the gas blocking valve 10 and the liquid blocking valve 11 are opened, the refrigerant sealed in the outdoor unit is opened to the indoor unit side, the air conditioner is started in the cooling operation, and the refrigeration cycle system diagram shown in FIG. As shown in Fig. 3, the refrigerant is flown as indicated by solid arrows.
The state in which the temperature of the gas refrigerant on the discharge side of the compressor 1 is reduced, that is, the refrigeration cycle is controlled by the indoor expansion valve 4 so that the discharge gas superheat degree becomes a certain value TdSH0 or more until the refrigeration cycle is stabilized. Is determined to be stable, the refrigerant charging solenoid valve 14 is opened. The liquid refrigerant flowing out from the refrigerant cylinder 50 passes through the refrigerant-filled electromagnetic valve 14 as indicated by the broken arrow, flows into the bypass portion of the supercooling heat exchanger 9, and evaporates while dissipating heat to the high-temperature and high-pressure refrigerant flowing out from the liquid receiver 5. It is gasified and flows into the accumulator 8 inlet.

  If the discharge gas superheat degree is equal to or greater than a certain value TdSH0, the difference between the saturation temperature calculated from the discharge pressure sensor 15 and the supercooling heat exchanger outlet temperature thermistor 17 provided on the outlet side of the supercooling heat exchanger 9 A certain supercooling heat exchanger outlet supercooling degree SC is calculated, and from the refrigerant cylinder 50 until the value of the supercooling heat exchanger outlet supercooling degree SC becomes equal to or higher than the preset supercooling degree α at the time of charging the appropriate refrigerant. The refrigerant charging is completed by closing the refrigerant charging electromagnetic valve 14 when the value of the supercooling heat exchanger outlet supercooling degree SC becomes equal to or higher than the supercooling degree α at the time of charging the appropriate refrigerant.

FIG. 3 shows a Mollier diagram of a refrigeration cycle at the time of refrigerant filling of the air conditioner equipped with the refrigerant filling device of the present invention, and a solid line and a circle indicate the refrigeration cycle 60 at the time of refrigerant proper charging, A square mark indicates the refrigeration cycle 61 when the refrigerant is insufficiently charged.
Before the refrigerant is properly filled in the air conditioner, a refrigeration cycle indicated by a broken line in the Mollier diagram shown in FIG. 3 is obtained, and the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 becomes b ′. 1, flows into the outdoor heat exchanger 7, exchanges heat with the air and dissipates heat to become c ′, and flows into the liquid receiver 5. Here, since the refrigerant in the air conditioner is insufficient, the liquid refrigerant does not accumulate in the liquid receiver 5 and flows out from the liquid receiver 5 in a gas-liquid two-phase state, and in the supercooling heat exchanger 9. Cooled by the refrigerant flowing in from the refrigerant cylinder 50, becomes d 'state, decompressed by the indoor expansion valve 4, becomes e', evaporates by exchanging heat with air in the indoor heat exchanger 3, and is sucked into the compressor 1 in the state of a ' .
After the refrigerant is properly filled in the air conditioner, a refrigeration cycle indicated by a solid line in the Mollier diagram shown in FIG. 3 is obtained, and the high-temperature and high-pressure gas refrigerant compressed by the compressor 1 becomes b. , And flows into the outdoor heat exchanger 7, exchanges heat with air and dissipates heat, and becomes c and flows into the liquid receiver 5. Here, since the refrigerant in the air conditioner is filled with an appropriate amount, the liquid refrigerant accumulates in the liquid receiver 5 and flows out from the liquid receiver 5 in a liquid single-phase state, and the supercooling heat exchanger 9. The refrigerant is cooled by the refrigerant flowing in from the refrigerant cylinder 50 and becomes d in the supercooled state, depressurized by the indoor expansion valve 4, becomes e and exchanges heat with air in the indoor heat exchanger 3, and is sucked into the compressor 1 in the state of a. .

  FIG. 4 is a characteristic diagram showing the correlation between the refrigerant filling ratio and the degree of refrigerant supercooling at the outlet of the supercooling heat exchanger 9, and the refrigerant shortage state in which the refrigerant filling ratio is less than 100% is shown in FIG. In the Mollier diagram of the refrigeration cycle, the state becomes a broken line, and the refrigerant state at the outlet of the supercooling heat exchanger 9 becomes a gas-liquid two-phase state at point d ′, so that the refrigerant supercooling degree is 0K. When additional refrigerant is charged and the refrigerant charging rate approaches 100%, the amount of refrigerant existing in the outdoor heat exchanger 7 acting as a condenser increases, so the refrigerant state at the outlet of the outdoor heat exchanger 7 Moves from c ′ to c, and the refrigerant state at the outlet of the supercooling heat exchanger 9 becomes a supercooling state, so that the degree of supercooling increases to the right as shown by the solid line. When the refrigerant is further charged, the added refrigerant only accumulates in the liquid receiver 5, and the amount of refrigerant existing in the outdoor heat exchanger 7 does not change, so that the degree of supercooling does not increase. When the refrigerant is further charged, the refrigerant overflows from the liquid receiver 5, so that the amount of refrigerant existing in the outdoor heat exchanger 7 increases, and the refrigerant state at the outlet of the outdoor heat exchanger 7 becomes a supercooled state. The refrigerant supercooling degree at the outlet of the heat exchanger 9 increases.

  As described above, in the present refrigerant filling apparatus, when the refrigerant is additionally charged, the air conditioning apparatus is operated in a cooling operation, and the refrigerant filling operation is performed while ensuring the pressure difference between the internal pressure of the refrigerant cylinder 50 and the inlet of the accumulator 8. Therefore, the refrigerant can be quickly filled. Further, since the liquid refrigerant flowing out from the refrigerant cylinder 50 is heated and gasified by the supercooling heat exchanger 9 and filled, the liquid return to the compressor 1 can be suppressed, and the reliability of the compressor 1 during refrigerant filling is improved. Can be secured. Furthermore, since the refrigerant subcooling degree at the outlet of the supercooling heat exchanger 9 is detected and the refrigerant charging operation is performed while opening and closing the refrigerant charging electromagnetic valve 14, the refrigerant charging operation can be automated, and the installation time of the air conditioner Can be shortened.

Next, another embodiment of the present invention will be described with reference to FIGS.
In FIG. 5, a bypass circuit is provided between the liquid receiver 5 and the main flow part of the supercooling heat exchanger 9, and the bypass circuit is connected between the bypass part of the supercooling heat exchanger 9 and the refrigerant filling electromagnetic valve 14, A supercooling bypass expansion valve 21 is provided in the middle of the bypass circuit.
In the refrigerant charging method, when the cooling operation is performed, the supercooling bypass expansion valve 21 attached to the bypass circuit is fixed at a predetermined opening degree, and the refrigerant is always supplied to the bypass portion of the supercooling heat exchanger 9 during the refrigerant charging. Done.

  FIG. 6 is a characteristic diagram showing the correlation between the refrigerant filling ratio and the degree of refrigerant supercooling at the outlet of the supercooling heat exchanger 9. In the figure, the solid line indicates that the supercooling bypass expansion valve described in FIG. The broken line indicates the characteristic 71 when the supercooling bypass expansion valve is opened at a predetermined opening degree. When the supercooling bypass expansion valve 21 is opened at a predetermined opening, the flow rate to the bypass portion of the supercooling heat exchanger 9 is the amount flowing from the refrigerant cylinder 50 and the bypass amount passing through the supercooling bypass expansion valve 21. Therefore, the cooling capacity in the supercooling heat exchanger 9 is increased. For this reason, compared with the case where the supercooling bypass expansion valve 21 is not present or closed, the refrigerant at the outlet of the supercooling heat exchanger 9 becomes supercooled even when the refrigerant is insufficient, and the degree of supercooling is generated. In the case of proper filling, the degree of supercooling increases.

  As described above, the bypass circuit provided with the supercooling bypass expansion valve 21 is provided between the main flow part of the liquid receiver 5 and the supercooling heat exchanger 9 so that the refrigerant flows through the bypass circuit when the refrigerant is charged. As a result, the change in the degree of refrigerant supercooling at the outlet of the supercooling heat exchanger 9 can be increased, and the excess or deficiency of the refrigerant can be determined with higher accuracy. Further, since the degree of refrigerant supercooling occurs from the state of refrigerant shortage, the ratio of refrigerant shortage can be calculated from this degree of supercooling.

Next, another embodiment of the present invention will be described with reference to FIG.
FIG. 7 is a refrigeration cycle system diagram of an air conditioner equipped with a refrigerant filling device. The refrigerant filling device uses an outdoor heat exchanger 7 instead of the discharge pressure sensor input to the supercooling degree calculation means 30. A condensation temperature thermistor 18 for detecting the temperature on the outlet side is provided between the outdoor heat exchanger 7 and the liquid receiver 5, and an output signal of the condensation temperature thermistor 18 is input to the subcooling calculation means 30, and the condensation temperature thermistor 18 is detected. The refrigerant supercooling degree at the outlet of the supercooling heat exchanger 9 is calculated from the difference between this value and the value of the supercooling heat exchanger outlet temperature thermistor 17. As an alternative to the discharge gas superheat degree calculation means 32, an indoor liquid temperature thermistor 20 and an indoor gas temperature thermistor 19 are provided at the inlet and outlet of the indoor heat exchanger 3, respectively, and the output signals of the thermistors are subjected to heat exchange heat. The degree of refrigerant superheat of the indoor heat exchanger 3 is calculated from the difference between the value of the indoor gas temperature thermistor 19 and the value of the indoor liquid temperature thermistor 20, and the degree of indoor expansion valve 4 is calculated based on the degree of refrigerant superheat. Control the opening.
Therefore, since an inexpensive temperature thermistor is used as an input signal to the supercooling degree calculation means or the superheat degree calculation means, an inexpensive temperature thermistor is used, so that the cost of the refrigerant filling device can be reduced.

Next, still another embodiment of the present invention will be described with reference to FIGS.
FIG. 8 is a refrigeration cycle system diagram of an air conditioner equipped with a refrigerant filling device. The refrigerant filling device is connected to a refrigerant filling blocking valve 22 at a pipe portion connecting the inlet side of the refrigerant filling electromagnetic valve 14 and the refrigerant cylinder 50. A pipe connection is made between the refrigerant charging prevention valve 22 and the refrigerant charging electromagnetic valve 14 so as to bypass between the supercooling heat exchanger 9 and the liquid blocking valve 11, and a precharge check valve 23 is connected to the bypass circuit. Provided.
FIG. 9 shows a refrigerant filling flowchart by the refrigerant filling device, in which the minimum amount of refrigerant necessary for the outdoor unit is enclosed in the outdoor unit in advance, and the gas side connection pipe after the outdoor unit and the indoor unit are installed on site In order to remove air, moisture and the like in the liquid side connection pipe and the indoor unit, a vacuum pump or the like is connected to the gas side service port 12 and the liquid side service port 13 to evacuate the inside of the pipe and the inside of the machine pipe. Then, after opening the gas blocking valve 10 and the liquid blocking valve 11 to open the refrigerant sealed in the outdoor unit to the indoor unit side, the refrigerant charging blocking valve 22 is opened. When the gas blocking valve 10 and the liquid blocking valve 11 are opened, the internal pressure in the refrigeration cycle is lowered, and a differential pressure is generated between the internal pressure of the refrigerant cylinder 50 and the liquid connection is made through the precharge check valve 23 using this pressure difference. The refrigerant is filled on the piping side. Here, when the pressure fluctuation in the refrigeration cycle is smaller than the predetermined value SP, the refrigerant cannot be filled into the refrigeration cycle from the refrigerant cylinder 50 any more, so the refrigeration cycle is started in the cooling operation and the refrigeration shown in FIG. Let the coolant flow as shown by the solid arrows in the cycle diagram. After that, it is the same as the refrigerant filling method shown in FIG.
According to this example, since the refrigerant is filled using the pressure difference between the internal pressure in the refrigeration cycle and the internal pressure of the refrigerant cylinder 50 before the cooling operation, the connection pipe length is very long and the outdoor unit is filled in advance. Even when the cooling operation cannot be performed with the amount of the refrigerant, the refrigerant can be automatically charged, and the construction time of the air conditioner can be shortened.

The air conditioner in which one indoor unit is installed for one outdoor unit has been described above. However, multi-room air in which a plurality of two or more indoor units are installed for one outdoor unit. Even a harmony device has the same effect.
In addition, as a method for determining whether or not the amount of refrigerant in the refrigeration cycle is appropriate based on the degree of refrigerant supercooling at the outlet of the supercooling heat exchanger, the case of the refrigerant charging operation has been described. In the case of operation, the refrigerant amount determination is performed to determine whether the refrigerant amount in the refrigeration cycle is appropriate using the refrigerant supercooling degree.
In addition, a storage tank for adjusting the amount of refrigerant is installed in the outdoor unit in place of the refrigerant cylinder. The storage tank has an inlet and an outlet. An electromagnetic valve is connected between the inlet of the storage tank and the high-pressure part of the refrigeration cycle. And the refrigerant quantity in the refrigeration cycle can be freely and automatically changed by connecting the outlet portion of the storage tank and the refrigerant charging solenoid valve.
Furthermore, when the type of refrigerant to be filled by the refrigerant filling device is a non-azeotropic refrigerant mixture, the refrigerant is filled from the refrigerant cylinder with the liquid refrigerant, so that the refrigerant can be quickly filled while suppressing a change in composition.
Furthermore, the means for cooling the temperature of the subcooling heat exchanger outlet temperature thermistor section and the means for heating the liquid refrigerant filled from the refrigerant cylinder are performed by one supercooling heat exchanger. Means for cooling the temperature of the outlet temperature thermistor section (for example, a supercooling heat exchanger is provided on the downstream side of the receiver) and means for heating the liquid refrigerant charged from the refrigerant cylinder (for example, charging from the refrigerant cylinder) The same applies to a case where a heating air heat exchanger for reducing the pressure of the liquid refrigerant to be exchanged with the outdoor air is provided, and the liquid refrigerant is passed through the heating air heat exchanger.

Next, still another embodiment of the present invention will be described with reference to FIG.
FIG. 10 shows a refrigeration cycle system of an air conditioner equipped with a refrigerant charging device provided with display means for displaying work content information at the time of refrigerant charging during refrigerant charging or at the end of charging and information on the result of determining whether or not the refrigerant is charged. The figure is shown. The refrigerant filling device includes a refrigerant amount suitability determining unit that determines whether or not the amount of refrigerant charged in the refrigeration cycle is appropriate based on the output signal of the supercooling degree calculating unit, and the output signal of the refrigerant amount suitability determining unit is Input to the microcomputer. In addition, the microcomputer has a configuration in which display information is provided so that the operation information of the air conditioner such as the automatic refrigerant charging operation, the normal operation, and the test operation is input and the information in the microcomputer is displayed. As a display means, a 7-segment display device and a liquid crystal display device arranged on the control board of the outdoor unit, a display unit of a remote controller for controlling the start and stop of each indoor unit, and starting each indoor unit collectively And a display unit of a centralized management device for controlling stop and stop.

Next, the display content of the display means at the time of refrigerant filling will be described. When a switch or the like is turned on for charging the refrigerant, the display means can recognize that the refrigerant charging operation is in progress. When the Chinese character cannot be displayed as in the 7-segment display device, a combination of alphanumeric characters (for example, “RCH” )) When a Chinese character display such as a liquid crystal is possible, a display that can be recognized by a general person (for example, refrigerant is being charged) is displayed. In addition, when refrigerant charging is normally completed, a combination of alphanumeric characters is displayed when the Chinese character cannot be displayed as in the 7-segment display device so that the display means can recognize that the refrigerant charging operation has been normally completed (for example, “END”), when a Chinese character display such as liquid crystal is possible, a display that can be recognized by a general person (for example, completion of refrigerant charging) is displayed.
Also, if the refrigerant in the refrigerant cylinder is emptied during the refrigerant charging operation, the amount of refrigerant circulating through the supercooling heat exchanger decreases, so the amount of cooling heat in the supercooling heat exchanger decreases, and the supercooling heat exchanger Since the refrigerant supercooling degree at the outlet is lowered, it can be recognized that the refrigerant cylinder is empty. Therefore, when the refrigerant supercooling degree is reduced even though the refrigerant is being charged, the indication means displays that the refrigerant cylinder is empty and the refrigerant cylinder is empty or the refrigerant cylinder is empty. To do.

Furthermore, “refrigerant shortage”, “refrigerant appropriateness”, etc., which are the results of the refrigerant quantity suitability determination means, are also displayed in accordance with the display device. Further, the time required from the refrigerant amount suitability determination means to the completion of refrigerant charging is calculated, and the calculated time is displayed on the display means.
According to the above, since the display means displays the state of the refrigerant filling operation, the state in the refrigerant cylinder, and the result of the refrigerant quantity suitability determination means, is the current operation of the air conditioner being performed for refrigerant filling? In addition, it is possible to understand at a glance how much the refrigerant is charged. Further, when a 7-segment display device disposed on the control board of the outdoor unit is used as the display means, the cost of the display portion can be very low. In addition, when the outdoor unit is provided with a liquid crystal display device, it can be reliably recognized.

  In addition, when the display unit of the remote control of the indoor unit or the display unit of the centralized management device is used as the display means, it is possible to recognize the refrigerant charging operation, the refrigerant charging amount, etc. even when away from the outdoor unit. Furthermore, a refrigerant charge amount suitability determining means for determining the suitability of the refrigerant amount filled in the refrigeration cycle from the refrigerant supercooling degree detection means is provided, and the work content information at the time of refrigerant filling such as during refrigerant filling or completion of filling, By providing display means for displaying the information determined by the refrigerant charge amount suitability determination means, the operation of the air conditioner is performed for refrigerant charge, and the amount of refrigerant charged in the air conditioner is appropriate. Anyone can easily and reliably recognize if there is.

  Furthermore, a bypass circuit is provided so as to bypass the pipe connecting the receiver and the supercooling heat exchanger between the bypass portion inlet of the supercooling heat exchanger and the refrigerant-filled solenoid valve, and the bypass circuit is supercooled and bypass expanded. By providing a valve and allowing the refrigerant to flow through the bypass circuit when charging the refrigerant, it is possible to increase the change in the degree of refrigerant supercooling at the outlet of the supercooling heat exchanger for determining whether the refrigerant is excessive or insufficient. Excess or deficiency can be determined with higher accuracy. Further, since the refrigerant supercooling degree is generated from the refrigerant shortage state, the refrigerant shortage ratio can be calculated from the supercooling degree.

  Furthermore, a blocking valve is provided upstream of the refrigerant charging solenoid valve, and a bypass circuit is provided via a check valve so that the refrigerant flows from between the refrigerant charging solenoid valve and the blocking valve to the outlet side of the main flow section of the supercooling heat exchanger. Since the refrigerant is filled from the check valve part to the liquid blocking valve side using the pressure difference between the internal pressure in the refrigeration cycle and the internal pressure of the refrigerant cylinder before the cooling operation, the connection pipe length is very long and the outdoor unit Even in the case where the cooling operation cannot be performed with the amount of refrigerant filled in the refrigerant, the refrigerant can be automatically charged, and the construction time of the air conditioner can be shortened.

The refrigeration cycle system diagram which shows one Embodiment of this invention. The refrigerant | coolant filling flowchart figure which showed the refrigerant | coolant filling method of this invention. The Mollier diagram of the refrigerating cycle at the time of refrigerant | coolant filling by one Embodiment of this invention. The characteristic view showing the correlation of the refrigerant | coolant filling ratio and refrigerant | coolant supercooling degree of a supercooling heat exchanger exit by one Embodiment of this invention. The refrigeration cycle system diagram which shows other embodiment. The characteristic view showing the correlation of the refrigerant | coolant filling ratio and refrigerant | coolant supercooling degree of a supercooling heat exchanger exit by other embodiment. The refrigeration cycle system diagram which shows other embodiment. Furthermore, the refrigeration cycle system diagram which shows other embodiment. Furthermore, the refrigerant | coolant filling flowchart figure which showed other embodiment refrigerant | coolant filling method. Furthermore, the refrigeration cycle system diagram which shows other embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Compressor, 3 ... Indoor heat exchanger, 4 ... Indoor expansion valve, 5 ... Liquid receiver, 6 ... Outdoor expansion valve, 7 ... Outdoor heat exchanger, 8 ... Accumulator, 9 ... Supercooling heat exchanger, 10 DESCRIPTION OF SYMBOLS ... Gas blocking valve, 11 ... Liquid blocking valve, 12 ... Gas side service port, 13 ... Liquid side service port, 14 ... Refrigerant filling electric valve, 15 ... Discharge pressure sensor, 16 ... Discharge temperature thermistor, 17 ... Supercooling heat exchange Outlet temperature thermistor, 18 ... condensation temperature thermistor, 19 ... indoor gas temperature thermistor, 20 ... indoor liquid temperature thermistor, 21 ... supercooling bypass expansion valve, 22 ... refrigerant charging prevention valve, 23 ... precharge check valve, 30 ... Supercooling degree calculating means, 31 ... Refrigerant charging solenoid valve opening / closing means, 32 ... Discharge gas superheat degree calculating means, 33 ... Heat exchange superheat degree calculating means, 50 ... Refrigerant cylinder, 34 ... Refrigerant amount suitability determining means, 35 ... Microcomputer Pew , 36 ... display unit.

Claims (6)

Refrigeration cycle in which an outdoor unit having a compressor, an outdoor heat exchanger, a pressure reducing device, and a liquid receiver, and an indoor unit having an indoor heat exchanger and a pressure reducing device are pipe-connected to the outdoor unit. In the refrigerant filling device that fills the inside or additionally fills the refrigerant,
A main flow portion of a supercooling heat exchanger having a subflow portion is disposed between the liquid receiver of the outdoor unit and the indoor unit, and one of the subflow portions is placed in a refrigerant cylinder via a refrigerant filling electromagnetic valve, and the other Is connected to the suction side of the compressor, and after the refrigeration cycle is determined to be stable, the refrigerant charging solenoid valve is opened to fill the refrigerant, and the refrigerant supercooling on the outlet side of the main flow portion of the supercooling heat exchanger A refrigerant that controls opening and closing of the refrigerant filling solenoid valve so that the refrigerant filling solenoid valve is closed to complete the refrigerant filling when the degree becomes equal to or more than a preset value at the time of proper refrigerant filling. Filling equipment.   The refrigerant charging device according to claim 1, further comprising a bypass circuit that bypasses between an inlet of the secondary flow portion and the refrigerant charging electromagnetic valve from a pipe connecting the liquid receiver and the supercooling heat exchanger, A refrigerant charging device, wherein a bypass circuit is provided with a supercooling bypass expansion valve.   2. The second bypass circuit according to claim 1, wherein a blocking valve is provided on an upstream side of the refrigerant filling electromagnetic valve, and the refrigerant flows from between the refrigerant charging electromagnetic valve and the blocking valve to an outlet side of the main flow portion. A refrigerant filling apparatus comprising: 2. The discharge pressure sensor according to claim 1, comprising: a discharge pressure sensor provided on a discharge side of the compressor; and a temperature thermistor provided on an outlet side of a main flow portion of the supercooling heat exchanger. calculating a Atsushi Kazu from the pressure values according to the computed saturated temperature and refrigerant charging apparatus difference and said to Rukoto and the refrigerant supercooling degree of the output value of the temperature thermistor. 2. The refrigerant filling according to claim 1, wherein the refrigerant superheating degree on the discharge side of the compressor is detected, and the refrigeration cycle is controlled so that the refrigerant superheating degree becomes a predetermined value during the refrigerant filling. apparatus. A refrigerant charging method for charging a refrigerant into a refrigeration cycle in which an outdoor unit having a compressor, an outdoor heat exchanger, a pressure reducing device, and a liquid receiver, and an indoor unit having an indoor heat exchanger and a pressure reducing device are connected by piping. And a main flow part of a supercooling heat exchanger having a subflow part is disposed between the receiver of the outdoor unit and the indoor unit, and one of the subflow parts is connected to a refrigerant cylinder via a refrigerant-filled electromagnetic valve. The other is connected to the suction side of the compressor, and after the refrigeration cycle is determined to be stable, the refrigerant filling electromagnetic valve is opened to fill the refrigerant, and the outlet side of the main flow portion of the supercooling heat exchanger is When the refrigerant supercooling degree is equal to or higher than a preset value for charging proper refrigerant, the refrigerant filling solenoid valve is closed to control the opening and closing of the refrigerant filling solenoid valve so that the refrigerant filling is completed. Refrigerant filling method characterized by filling .

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