JP5306450B2 - Refrigeration air conditioner and refrigerant filling method thereof - Google Patents

Abstract

A refrigerant charging method for a refrigeration air-conditioner provided with a compressor (1) for sucking a refrigerant and discharging the refrigerant after compressing the refrigerant. The refrigerant discharged from the compressor (1) is returned to the suction side of the compressor (1) via an on-off valve (5), and a refrigerant is charged between the on-off valve (5) and the suction side of the compressor (1) from a refrigerant charging port (7) via a refrigerant charging on-off device (6).

Description

  The present invention relates to a refrigeration air conditioner in which an outdoor unit and an indoor unit are connected by a refrigerant pipe, and more particularly to a technique for automatically filling a refrigerant.

  Conventionally, a technique for charging the refrigerant by estimating an excess or deficiency of the refrigerant amount in the refrigerant circuit of the refrigeration air conditioner from the operation state of the refrigeration cycle has been proposed (for example, Patent Documents 1 and 2).

JP 2008-64456 A JP 2008-232579 A

However, conventionally, when it is determined that the refrigerant filled in the refrigerant circuit is insufficient and the refrigerant is charged, the liquid refrigerant once enters the accumulator. When liquid refrigerant enters the accumulator, heat is radiated from the accumulator. Therefore, even when hot gas is blown into the accumulator, the refrigerant hardly evaporates, and there is a problem that it takes time until the liquid in the accumulator evaporates.
In addition, when the outside air temperature is low, it is difficult to determine whether or not the liquid in the accumulator has evaporated, and as a result of determining the refrigerant amount while the liquid refrigerant is accumulated in the accumulator, there is a possibility that the refrigerant is overfilled. There was a problem that there was.

  This invention respond | corresponds to the said subject, and proposes the refrigerating air conditioning apparatus which can complete refrigerant | coolant filling more promptly and more correctly.

The present invention is a refrigerating and air-conditioning apparatus comprising at least a compressor, a condenser, a throttling device, and an evaporator, wherein the refrigerant circuit branches off from the discharge side of the compressor and is connected to the suction side of the compressor via an opening / closing means the refrigerant which is connected via a refrigerant filling switch between the hot gas bypass circuit that connects a connecting portion between the refrigerant circuit of the switching means and the compressor suction side on the hot gas bypass circuit and possess a fill port, and calculates the difference SC between the refrigerant temperature of the condenser outlet and the saturation temperature of the discharge pressure of the compressor, as compared the calculated SC and the SCm of the target value, SC <SCm In this case, both the opening / closing means and the refrigerant charging switch are opened.

  In the refrigeration air conditioner of the present invention, when the refrigerant is charged, the liquid refrigerant filled with the heat of the hot gas is evaporated by joining the liquid refrigerant to be charged with the discharged refrigerant (hot gas) discharged from the compressor. Since the main refrigerant circuit is filled in this state, the refrigerant filling can be completed promptly and accurately without taking time to determine the amount of refrigerant in the refrigeration air conditioner.

1 is a refrigerant circuit diagram of a refrigeration air conditioner according to Embodiment 1 of the present invention. The flowchart of control of the expansion apparatus of the refrigeration air conditioning apparatus which concerns on Embodiment 1 of this invention. The flowchart of control of the refrigerant | coolant automatic charging of the refrigerating and air-conditioning apparatus which concerns on Embodiment 1 of this invention. The refrigerant circuit figure of the refrigerating and air-conditioning apparatus which concerns on Embodiment 2 of this invention. The flowchart of control of the refrigerant | coolant automatic charging of the refrigerating and air-conditioning apparatus which concerns on Embodiment 2 of this invention. The flowchart of control of the refrigerant | coolant automatic charging of the refrigerating and air-conditioning apparatus which concerns on Embodiment 3 of this invention. FIG. 6 is a refrigerant circuit diagram of a refrigeration air conditioner according to Embodiment 4 of the present invention. The work flowchart regarding the update of the refrigerating air-conditioning apparatus which concerns on Embodiment 4 of this invention. The flowchart of control of the refrigerant | coolant automatic charging in the air_conditionaing | cooling operation of the refrigerating air conditioning apparatus which concerns on Embodiment 4 of this invention. The flowchart of the control of refrigerant | coolant automatic filling in the heating operation of the refrigerating air conditioner which concerns on Embodiment 4 of this invention. The refrigerant circuit figure of the refrigerating and air-conditioning apparatus which concerns on Embodiment 5 of this invention. The flowchart of control of the automatic refrigerant | coolant filling in the air_conditionaing | cooling operation of the refrigerating air conditioning apparatus which concerns on Embodiment 5 of this invention. The refrigerant circuit figure of the refrigerating air-conditioning apparatus which concerns on Embodiment 6 of this invention. The flowchart of control of the refrigerant | coolant automatic filling of the refrigerating air conditioner which concerns on Embodiment 6 of this invention.

Embodiment 1 FIG.
FIG. 1 shows a refrigerant circuit diagram of a refrigerating and air-conditioning apparatus according to Embodiment 1 of the present invention. In FIG. 1, 1 is a compressor, 2 is a condenser, 3 is an expansion device, and 4 is an evaporator, and these constitute a main refrigerant circuit. Further, a hot gas bypass circuit (refrigerant circuit) is formed which branches the discharge side of the compressor 1 and reaches the intake of the compressor via an on-off valve 5 as a flow path opening / closing means. Further, a refrigerant circuit between the on-off valve 5 on the hot gas bypass circuit and the suction side of the compressor is branched, and a refrigerant filling port 7 is connected via a refrigerant filling on-off valve 6. Reference numeral 8 denotes a pressure sensor that detects a pressure at a high-pressure portion on the discharge side of the compressor 1, and reference numeral 9 denotes a first temperature sensor that detects a refrigerant temperature on the discharge side of the compressor 1. Reference numeral 10 denotes a second temperature sensor that detects the temperature of the refrigerant at the outlet of the condenser 2, and reference numerals 11 and 12 denote third and fourth temperature sensors that detect the temperature of the refrigerant at the inlet / outlet of the evaporator 4.

  Next, the flow of the refrigerant in the refrigerant circuit refrigerant will be described. When the compressor 1 is driven, high-temperature and high-pressure gas refrigerant is discharged from the compressor and liquefied by the condenser. The liquefied refrigerant is squeezed to a low temperature by the expansion device 3, evaporated and vaporized by the evaporator, and then returned to the compressor 1.

  Control of the expansion device in such a refrigeration cycle will be described with reference to FIG. FIG. 2 is a flowchart showing an example of the control algorithm of the diaphragm device 3. The operation is started in STEP 1 and the control interval is taken in STEP 2, so that a predetermined time elapses and the process proceeds to STEP 3 after the predetermined time elapses. In STEP3, the inlet / outlet temperature of the evaporator 4 is measured by the third and fourth temperature sensors. In STEP 4, the difference SH between the evaporator inlet temperature Tein and the evaporator outlet temperature Teout is calculated. In STEP 5, the opening correction value ΔLEV of the expansion device 3 is determined according to the difference between the SH calculated in STEP 4 and the target value SHm, and the setting is performed. In STEP 6, it is determined whether or not to end the operation. If the operation is ended, the process proceeds to STEP 7 and the operation is ended. If the operation is not ended, the process returns to STEP 2.

  A method of determining the amount of refrigerant and automatically charging the refrigerant in the refrigeration cycle that performs such operation will be described with reference to FIG. FIG. 3 is a flowchart showing an algorithm when the refrigerant is automatically charged. In FIG. 3, in a state where the refrigerant supply cylinder containing the refrigerant is connected to the refrigerant charging port 7, in STEP 1, an operation for adjusting the refrigerant amount is started. As a start trigger, a service switch provided in the outdoor unit, a remote controller, an external contact input, a control signal from a personal computer or the like is used. In STEP2, in order to take a control interval, the process waits until a predetermined time elapses, and proceeds to STEP3 after the predetermined time elapses. In STEP 3, the discharge pressure Pd of the compressor 1 and the refrigerant temperature Tcout at the outlet of the condenser 2 are detected. In STEP 4, the difference SC between the saturation temperature Tsat (Pd) of the discharge pressure Pd and the refrigerant temperature Tcout at the outlet of the condenser 2 is calculated. In STEP5, the calculated SC is compared with the SCm of the target value. If SC ≧ SCm, the process proceeds to STEP6 and the refrigerant amount adjustment is finished. When SC <SCm, the routine proceeds to STEP 7 where the refrigerant filling on-off valve 6 is opened for a predetermined time, and the refrigerant is filled into the refrigerant circuit from the refrigerant supply cylinder through the refrigerant filling port 7. At the same time, the on-off valve 5 is opened. After filling the refrigerant for a predetermined time in STEP 7, proceed to STEP 2. When finishing the refrigerant amount adjustment, use a service display, remote control, personal computer for control, lamp display with electrical signals, etc. to notify the outside that the refrigerant amount adjustment has been completed. Good.

  As described above, when the refrigerant is charged in STEP 7, the on-off valve 5 is also opened so that the high-temperature gas refrigerant discharged from the compressor 1 flows into the hot gas bypass circuit, and the liquid filled from the refrigerant supply cylinder. After mixing with the refrigerant and evaporating it, it merges with the refrigerant flowing through the main circuit on the compressor 1 suction side. For this reason, the liquid refrigerant when the refrigerant is charged can be quickly evaporated without liquid back, so that the determination of the refrigerant amount can also be completed quickly. Moreover, since the dilution of the lubricating oil in the compressor 1 and liquid compression do not occur, a highly reliable system can be achieved.

Embodiment 2. FIG.
FIG. 4 shows a refrigerant circuit diagram according to Embodiment 2 of the present invention. The difference between FIG. 4 and FIG. 1 is that the refrigerant filling port 7 has a flow rate control between the on-off valve 5 on the hot gas bypass circuit and the suction side of the compressor 1 instead of the refrigerant filling on-off valve 6. It is connected through a possible second diaphragm device 46.

  A method for determining the amount of refrigerant and automatically filling the refrigerant in the refrigeration cycle as shown in FIG. 4 will be described with reference to FIG. FIG. 5 is a flowchart showing an algorithm when the refrigerant is automatically charged. In FIG. 5, in a state where the refrigerant supply cylinder is connected to the refrigerant filling port 7, the operation for adjusting the refrigerant amount is started in STEP 1. In STEP2, in order to take a control interval, the process waits until a predetermined time elapses, and proceeds to STEP3 after the predetermined time elapses. In STEP 3, the discharge pressure Pd of the compressor 1 and the refrigerant temperature Tcout at the outlet of the condenser 2 are detected. In STEP 4, the difference SC between the saturation temperature Tsat (Pd) of the discharge pressure Pd and the outlet refrigerant temperature Tcout of the condenser 2 is calculated. In STEP5, the calculated SC is compared with the SCm of the target value. If SC ≧ SCm, the process proceeds to STEP6 and the refrigerant amount adjustment is finished. When SC <SCm, the process proceeds to STEP 7 where the second expansion device 46 is opened, and the refrigerant is charged into the refrigerant circuit from the refrigerant supply cylinder through the refrigerant filling port 7. At the same time, the on-off valve 5 is opened. In STEP 8, the discharge pressure Pd of the compressor 1 and the discharge refrigerant temperature Td of the compressor 1 are detected. In STEP9, the difference SHd between the discharge refrigerant temperature Td of the compressor 1 and the saturation temperature Tsat (Pd) of the discharge pressure Pd of the compressor 1 is calculated. In STEP 10, the opening of the second expansion device 46 is corrected based on ΔLEV2 in accordance with the difference between the calculated SHd and the target value SHdm, and the process proceeds to STEP11. In STEP 11, if the predetermined time has elapsed, the process returns to STEP 2, and if the predetermined time has not elapsed, the process returns to STEP 7.

  As described above, when the refrigerant is filled from the refrigerant supply cylinder into the refrigerant circuit, the liquid flow back to the compressor 1 is controlled by adjusting the charging flow rate with the second throttle device 46 according to the discharge state of the compressor 1. When the discharge superheat degree of the compressor 1 is large, the throttle opening can be increased and the charging flow rate can be maximized within an appropriate range, so that quick refrigerant charging is possible. In the present embodiment, the method for controlling the flow rate of the refrigerant charged from the refrigerant supply cylinder so that the superheat degree of the refrigerant discharged from the compressor 1 becomes a predetermined target value determined in advance has been described. The same effect can be obtained by using the superheat degree of the refrigerant sucked into the machine 1 as an index.

Embodiment 3 FIG.
FIG. 6 is a flowchart showing an algorithm for automatic refrigerant charging according to Embodiment 3 of the present invention. The configuration of the refrigerant circuit here is the same as in the first embodiment. In FIG. 6, in a state where the refrigerant supply cylinder is connected to the refrigerant filling port 7, in STEP 1, an operation for adjusting the refrigerant amount is started. In STEP2, in order to take a control interval, the process waits until a predetermined time elapses, and proceeds to STEP3 after the predetermined time elapses. In STEP 3, the discharge pressure Pd of the compressor 1 and the refrigerant temperature Tcout at the condenser outlet are detected. In STEP 4, the difference SCi between the saturation temperature Tsat (Pd) of the discharge pressure Pd of the compressor 1 and the outlet refrigerant temperature Tcout of the condenser 2 is calculated. In STEP 5, the difference ΔSC between the SCi calculated this time and the previous calculation result SCi-1 is calculated. However, since there is no previous value for the first time, the previous value is set to 0. In STEP 6, it is determined whether or not ΔSC is “0”. If “0” is equal to or greater than the predetermined number of times, the refrigerant is not charged, so that the refrigerant supply cylinder is empty or not connected. STEP 7 Proceed to, and issue cylinder replacement signal. The notification method may be anything such as a service display, a remote control, a control personal computer, or a lamp display using an electrical signal. If ΔSC = 0 has not been detected a predetermined number of times, proceed to STEP 8. In STEP 8, the calculated SCi is compared with the SCm of the target value. If SCi ≧ SCm, the process proceeds to STEP 9 and the refrigerant amount adjustment is completed. When SCi <SCm, the routine proceeds to STEP 10, where the refrigerant filling on-off valve 6 is opened for a predetermined time, and the refrigerant is filled into the refrigerant circuit from the refrigerant supply cylinder through the refrigerant filling port 7. At the same time, the on-off valve 5 is opened. After filling the refrigerant for a predetermined time in STEP 10, proceed to STEP2.

  By the above operation, it is possible to prevent the refrigerant supply cylinder 7 from being connected to the refrigerant supply port 7 or to continue the operation for charging the refrigerant while the refrigerant supply cylinder is empty. It is possible to make the system highly reliable.

Embodiment 4 FIG.
FIG. 7 shows a refrigerant circuit diagram of a refrigerating and air-conditioning apparatus according to Embodiment 4 of the present invention. In FIG. 7, 1 is a compressor, 21 is a four-way valve, 22 is a heat source side heat exchanger, 23 is an accumulator, 24 is a refrigerant heat exchanger, 26 is an outdoor expansion device, and 14 is an on-off valve. The main refrigerant circuit of the unit 51 is configured. Reference numeral 13 denotes an on-off valve on a circuit that bypasses the refrigerant heat exchanger 24. Further, on the liquid side of the refrigerant heat exchanger 24, the refrigerant heat exchanger and the on-off valve 14 are branched, and a refrigerant circuit between the gas pipe 102 on the gas side and the refrigerant heat exchanger 24 is connected via the expansion device 17. Merge. The pipe branched from the discharge pipe of the compressor 1 is joined to the refrigerant circuit between the four-way valve 21 and the accumulator 23 via the on-off valve 5 and branched between the junction and the on-off valve 5 to provide a refrigerant filling on-off valve. The refrigerant charging port 7 is connected through 6.
The pipe connected to the bottom of the accumulator 23 is connected to the recovery device 25 via the on-off valve 15, and the upper portion of the recovery device 25 is connected to the refrigerant circuit between the four-way valve 21 and the accumulator 23 via the on-off valve 16. The The piping connected to the bottom of the accumulator 23 branches off from the on-off valve 15 and is connected to the refrigerant circuit between the accumulator 23 and the compressor 1 through the on-off valve 19.
Further, 8 is a pressure sensor that detects the pressure at the high-pressure section on the discharge side of the compressor 1, and 9 is a first temperature sensor that detects the temperature of the refrigerant on the discharge side of the compressor 1. Reference numeral 10 denotes a second temperature sensor that detects the temperature of the refrigerant at the outlet of the heat source side heat exchanger 22. Reference numeral 18 denotes a refrigerant circuit between the four-way valve 21 and the accumulator 23. The fifth temperature sensor is installed downstream of the junction of the hot gas bypass circuit that merges via the on-off valve 5 and detects the refrigerant temperature. . Reference numeral 20 denotes a second pressure sensor for detecting the pressure of the refrigerant passing through the liquid pipe 101, and reference numeral 28 denotes a third pressure sensor for detecting the pressure of the refrigerant passing through the refrigerant circuit between the four-way valve 21 and the accumulator 23. Here, the heat source side unit 51 is configured as described above.

  On the other hand, 3a and 3b are expansion devices, and 27a and 27b are load-side heat exchangers. 11a and 11b are third temperature sensors that detect the temperature of the refrigerant between the expansion devices 3a and 3b and the load side heat exchangers 27a and 27b, and 12a and 12b are between the load side heat exchanger and the gas pipe 102. It is a 4th temperature sensor which detects the temperature of a refrigerant | coolant. These constitute load-side units 52a and 52b. The subscripts a and b indicate multi-type air conditioners to which a plurality of indoor units are connected.

  Reference numeral 101 denotes a liquid pipe, and reference numeral 102 denotes a gas pipe. For these, pipes embedded in a ceiling or the like used in an existing unit can be used. The liquid pipe 101 and the gas pipe 102 connect the heat source side unit 51 and the load side units 52a and 52b to constitute a refrigerant circuit.

  Using the unit as shown in FIG. 7, the flow of removing foreign matters such as deteriorated lubricating oil used in the existing unit in the existing liquid pipe 101 and gas pipe 102 prior to the air-conditioning operation is shown in FIG. This will be described with reference to a flowchart. First, update is started at STEP1. In STEP2, existing units (heat source side unit, load side unit) are removed. In STEP 3, install a new unit. In STEP 4, connect the new unit to the existing refrigerant piping. In STEP5, the liquid pipe 101, the gas pipe 102, and the load side units 52a and 52b are evacuated, and then the refrigerant for the load side unit is filled. In STEP6, the operation | movement which collects a foreign material is implemented, judging the refrigerant | coolant amount required for a system. In STEP 7, after confirming the cooling and heating operation as the air conditioner, the update is completed in STEP 8.

  Here, the detail of the driving | operation which collects a foreign material is demonstrated. First, the flow of the refrigerant when the foreign matter collecting operation is performed in the cooling mode will be described. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 reaches the heat source side heat exchanger 22 via the four-way valve 21 and is condensed and liquefied. The condensed and liquefied liquid refrigerant is squeezed by the outdoor expansion device 26 so that the detected value of the second pressure sensor 20 is equal to or lower than the pressure resistance of the existing refrigerant pipe, and becomes an intermediate-pressure liquid refrigerant. It is cooled by the heat exchanger 24 and flows to the liquid pipe 101 via the on-off valve 14. The liquid refrigerant that has flowed to the liquid pipe 101 flows to the load side unit while stripping off the foreign matter in the liquid pipe 101 with the flow of the refrigerant. The liquid refrigerant containing the foreign matter flowing to the load side unit is throttled to a low pressure by the expansion devices 3a and 3b, takes heat from the surroundings by the load side heat exchangers 27a and 27b, evaporates and cools itself, and is itself a liquid refrigerant. The refrigerant flows into the gas pipe 102. The gas-liquid two-phase refrigerant that has flowed to the gas pipe 102 flows to the heat source unit 51 while stripping off foreign matter in the gas pipe 102. The gas-liquid two-phase refrigerant containing foreign matter that has returned to the heat source side unit 51 exchanges heat with the high-pressure liquid refrigerant in the refrigerant heat exchanger 24 to become a complete gas refrigerant, and the accumulator via the four-way valve 21. It flows to 23. The gas refrigerant containing the foreign matter flowing into the accumulator 23 is separated in the accumulator 23, and the gas refrigerant returns to the compressor 1. The foreign matter separated in the accumulator 23 flows to the recovery device 25 via the on-off valve 15 and is stored in the recovery device 25. At this time, while a part of the dynamic pressure of the refrigerant changes to static pressure inside the accumulator 23, the pressure in the recovery device 25 becomes lower than the pressure of the accumulator 23 by opening the on-off valve 16, and thus the differential pressure Accordingly, the flow of foreign matter from the accumulator 23 to the recovery device 25 occurs. Regarding the control of the dryness of the gas-liquid two-phase refrigerant at the outlet of the load side unit, the degree of superheat of the refrigerant at the suction portion of the accumulator 23 calculated from the fifth temperature sensor 18 and the third pressure sensor 28 is determined. This is carried out by controlling the expansion devices 3a and 3b so as to be constant.

  After carrying out the above operation for a predetermined time, the control of the refrigeration air conditioner is changed as follows to check the refrigerant amount. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 reaches the heat source side heat exchanger 22 via the four-way valve 21 and is condensed and liquefied. The condensed and liquefied liquid refrigerant is squeezed by the outdoor expansion device 26 so that the detected value of the second pressure sensor 20 is equal to or lower than the pressure resistance of the existing refrigerant pipe, and becomes an intermediate-pressure liquid refrigerant. It is cooled until supercooling is applied by the heat exchanger 24, and a part thereof is throttled to a low pressure via the expansion device 17 and merges with the gas refrigerant flowing through the low-pressure gas part. The remaining liquid refrigerant flows into the liquid pipe 101 via the on-off valve 14. The liquid refrigerant that has flowed to the liquid pipe 101 flows to the load side unit, the liquid refrigerant that has flowed to the load side unit is throttled to a low pressure by the expansion devices 3a and 3b, and heat is supplied from the surroundings by the load side heat exchangers 27a and 27b. It steals, evaporates and cools itself, and the degree of superheat of the refrigerant at the outlet of the load-side heat exchanger, which is obtained as the difference between the detected values of the third temperature sensors 11a and 11b and the fourth temperature sensors 12a and 12b, is constant. The gas is gasified by being controlled to flow to the gas pipe 102. The gas refrigerant that has flowed to the gas pipe 102 flows to the heat source side unit 51. The gas refrigerant that has returned to the heat source side unit 51 merges with the low-temperature gas-liquid two-phase refrigerant that has flowed through the bypass circuit having the expansion device 17, and then exchanges heat with the high-pressure liquid refrigerant in the refrigerant heat exchanger 24. It becomes a complete gas refrigerant and flows to the accumulator 23 through the four-way valve 21. The gas refrigerant that has flowed to the accumulator 23 returns to the compressor 1. At this time, the on-off valve 15 installed in the pipe connected to the bottom of the accumulator 23 is closed to confine foreign matter, and the on-off valve 19 is opened and lubricated in the compressor 1 taken out together with the refrigerant. The oil flows into the suction pipe of the compressor 1 through the on-off valve 19 and is returned to the oil. In this way, by changing the refrigerant control method after collecting foreign matter, the state of the refrigerant in the liquid pipe 101 becomes a complete liquid, and the state of the refrigerant in the gas pipe 102 becomes a complete gas refrigerant, and air conditioning operation is performed. Therefore, the refrigerant amount can be accurately determined.

  Next, a method of automatically filling the refrigerant during the foreign matter recovery operation in the cooling will be described with reference to the flowchart of FIG. In FIG. 9, in STEP 1, the foreign substance recovery operation is started and the compressor 1 is started. In STEP2, the temperature Td of the refrigerant discharged from the compressor 1 is detected. In STEP 3, particularly in the initial state, the refrigerant circuit is filled with only the refrigerant that has been charged in the heat source side unit in advance and the refrigerant for the load side unit that has been filled after evacuation. Therefore, the detected discharge temperature Td is compared with the preset upper limit value Tdmax of the discharge temperature, and when Td> Tdmax, it is determined that the refrigerant is insufficient. The filling on-off valve 6 is opened and filled with refrigerant. If Td ≦ Tdmax in STEP 3, the process proceeds to STEP 4 to determine whether a predetermined time has elapsed. If the predetermined time has elapsed in STEP4, the process proceeds to STEP6, and if the predetermined time has not elapsed, the process returns to STEP2. In STEP 6, as described above, the control method is changed, and the operation of heating the refrigerant at the load side unit outlet is performed. In STEP 7, it is determined again whether the predetermined time has elapsed. If the predetermined time has elapsed, the process proceeds to STEP 8, where the refrigerant discharge pressure Pd discharged from the compressor 1 and the heat source side heat exchanger 22 Detect outlet temperature Tcout. In STEP 9, the difference SC between the saturation temperature Tsat (Pd) of Pd and Tcout is calculated, and in STEP 10, the SC and SC target value SCm are compared, and if SC ≧ SCm, the process proceeds to STEP 11 and the foreign matter collecting operation is completed. If SC <SCm, the process proceeds to STEP 12, and after opening and closing the on-off valve 5 and the refrigerant filling on-off valve 6 for a predetermined time, the refrigerant is charged from the refrigerant filling port 7, and then the process returns to STEP 7.

  Next, the flow of the refrigerant when the operation for collecting the foreign matter is performed in the heating mode will be described with reference to FIG. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows into the refrigerant heat exchanger 24 via the four-way valve 21, is cooled by the refrigerant heat exchanger 24, becomes a high-pressure gas-liquid two-phase refrigerant, and enters the gas pipe 102. Flowing. At this time, the high pressure is controlled to a pressure equal to or lower than the pressure resistance of the existing piping by the capacity control of the compressor 1 or the like. The gas-liquid two-phase refrigerant that has flowed to the gas pipe 102 flows to the load-side unit while stripping off foreign matters in the gas pipe 102 with the flow of the refrigerant. The gas-liquid two-phase refrigerant containing foreign matter that has flowed to the load-side unit radiates heat to the surroundings by the load-side heat exchangers 27a and 27b, condenses and heats it, and liquefies itself before being intermediated by the expansion devices 3a and 3b. It is squeezed to a pressure and flows into the liquid pipe 101 as a two-phase refrigerant containing foreign matter. The gas-liquid two-phase refrigerant that has flowed to the liquid pipe 101 flows to the heat source unit 51 while stripping off foreign matter in the liquid pipe 101. The gas-liquid two-phase refrigerant containing the foreign matter that has returned to the heat source side unit 51 flows into the refrigerant heat exchanger 24 via the on-off valve 14 and exchanges heat with the high-pressure gas refrigerant to produce a two-phase refrigerant having a high degree of dryness. After being reduced to a low pressure by the outdoor expansion device 26, it flows through the heat source side heat exchanger 22, where it completely evaporates and flows to the accumulator 23 via the four-way valve 21. The gas refrigerant containing the foreign matter that has flowed into the accumulator 23 is separated in the accumulator 23, and the gas refrigerant returns to the compressor 1. The foreign matter separated in the accumulator 23 flows to the recovery device 25 via the on-off valve 15 and is stored in the recovery device 25. At this time, while a part of the dynamic pressure of the refrigerant changes to static pressure inside the accumulator 23, the pressure in the recovery device 25 becomes lower than the pressure of the accumulator 23 by opening the on-off valve 16, and thus the differential pressure Accordingly, the flow of foreign matter from the accumulator 23 to the recovery device 25 occurs. Note that the degree of superheat of the refrigerant at the outlet of the heat source side heat exchanger 22 is controlled by the outdoor expansion device 26.

  After carrying out the above operation for a predetermined time, the control of the refrigeration air conditioner is changed as follows to check the refrigerant amount. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows through the four-way valve 21 to the refrigerant heat exchanger 24. However, since the refrigerant does not flow to the low-pressure side, it remains in the state of superheated gas without heat exchange. It flows to the gas pipe 102. At this time, the high pressure is controlled to a pressure equal to or lower than the pressure resistance of the existing piping by the capacity control of the compressor 1 or the like. The high-temperature gas refrigerant that has flowed to the gas pipe 102 flows to the load side unit. The high-temperature gas refrigerant that has flowed to the load-side unit radiates heat to the surroundings by the load-side heat exchangers 27a and 27b, condenses and heats it, liquefies itself, and then is throttled to the intermediate pressure by the expansion devices 3a and 3b. Then, the refrigerant flows into the liquid pipe 101 as a two-phase refrigerant containing foreign substances. The gas-liquid two-phase refrigerant that has flowed to the liquid pipe 101 flows to the heat source side unit 51. The gas-liquid two-phase refrigerant containing foreign matter that has returned to the heat source side unit 51 flows so as to bypass the refrigerant heat exchanger 24 via the on-off valve 13, and after being throttled to a low pressure by the outdoor throttling device 26, It flows through the exchanger 22 where it is completely vaporized and flows to the accumulator 23 via the four-way valve 21. In this way, by changing the refrigerant control method after collecting the foreign matter, the state of the refrigerant in the liquid pipe 101 becomes the same as that in the normal heating operation or slightly close to the liquid, and the state of the refrigerant in the gas pipe 102 is complete. Since the refrigerant becomes a gas refrigerant and is in a distribution state of the refrigerant when the air-conditioning operation is performed, the refrigerant amount can be accurately determined.

  Next, a method of automatically filling the refrigerant during the foreign matter recovery operation in heating will be described with reference to the flowchart of FIG. In FIG. 10, in STEP 1, the foreign substance recovery operation is started and the compressor 1 is started. In STEP2, the temperature Td of the refrigerant discharged from the compressor 1 is detected. In STEP 3, particularly in the initial state, the refrigerant circuit is filled with only the refrigerant previously charged in the heat source side unit 51 and the refrigerant for the load side unit filled after evacuation. Therefore, the detected discharge temperature Td is compared with the preset upper limit value Tdmax of the discharge temperature, and if Td> Tdmax, it is determined that the refrigerant is insufficient, and the process proceeds to STEP 5 together with the on-off valve 5. The refrigerant filling on-off valve 6 is opened and the refrigerant is filled from the refrigerant filling port 7. If Td ≦ Tdmax in STEP 3, the process proceeds to STEP 4 to determine whether a predetermined time has elapsed. If the predetermined time has elapsed in STEP4, the process proceeds to STEP6, and if the predetermined time has not elapsed, the process returns to STEP2. In STEP 6, as described above, the control method is changed, and the operation of bypassing the refrigerant heat exchanger 24 on the low pressure side is performed. In STEP 7, it is determined again whether the predetermined time has elapsed. If the predetermined time has elapsed, the process proceeds to STEP 8, and the refrigerant discharge pressure Pd discharged from the compressor 1 and the load-side heat exchanger 27a, The average value Tcout_ave of the outlet temperature 27b is detected and calculated. In STEP 9, the difference SC between the saturation temperature Tsat (Pd) of Pd and Tcout_ave is calculated. In STEP 10, the SC and SC target value SCm are compared. If SC ≧ SCm, the process proceeds to STEP 11 and the foreign matter recovery operation is completed. If SC <SCm, the process proceeds to STEP 12, and after opening and closing the on-off valve 5 and the refrigerant filling on-off valve 6 for a predetermined time to fill the refrigerant from the refrigerant filling port 7, the process returns to STEP 7.

  With the above operation, when the unit is updated using the existing refrigerant pipe, the unit itself can correctly determine the refrigerant amount and fill the refrigerant even when the shape of the existing pipe is embedded in the wall or ceiling. Therefore, the construction time can be shortened, and the refrigerant amount can be determined regardless of cooling or heating. Therefore, it can be set as the reliable system with respect to the amount of refrigerant | coolants irrespective of a season.

  In the present embodiment, the case where there are two indoor units has been described. However, it is obvious that the same effect can be obtained even in a system having three indoor units. Further, even when a plurality of heat source side units are connected, the same control method is possible by processing such as averaging the state of the outlet refrigerant of the heat source side heat exchanger by the same method.

Embodiment 5 FIG.
FIG. 11 shows a refrigerant circuit diagram of a refrigerating and air-conditioning apparatus according to Embodiment 5 of the present invention. This apparatus includes a heat source side unit 51, load side units 52 a and 52 b, and a shunt controller 53.
First, the configuration of the heat source side unit 51 will be described. 1 is a compressor, 21 is a four-way valve, 22 is a heat source side heat exchanger, 23 is an accumulator, 32a, 32b, 32c and 32d are check valves, which are connected to the main refrigerant circuit of the heat source side unit 51 Configure. Further, the pipe branched from the discharge pipe of the compressor 1 is joined to the refrigerant circuit between the four-way valve 21 and the accumulator 23 via the on-off valve 5, and the junction between the junction and the on-off valve 5 is branched to fill the refrigerant. A refrigerant charging port 7 is connected via the on-off valve 6. Reference numeral 8 denotes a pressure sensor that detects pressure at the high-pressure portion on the discharge side of the compressor 1, and 9 denotes a first temperature sensor that detects the temperature of the refrigerant on the discharge side of the compressor 1. These constitute the heat source unit 51.

  Next, the configuration of the load side unit will be described. 3a and 3b are expansion devices, and 27a and 27b are load-side heat exchangers. 11a and 11b are third temperature sensors that detect the temperature of the refrigerant between the expansion devices 3a and 3b and the load side heat exchangers 27a and 27b, and 12a and 12b are between the load side heat exchanger and the gas pipe. It is a 4th temperature sensor which detects the temperature of a refrigerant | coolant. These constitute load-side units 52a and 52b. The subscripts a and b indicate multi-type air conditioners to which a plurality of indoor units are connected.

  Finally, the configuration of the shunt controller 53 disposed between the heat source side unit 51 and the load side units 52a and 52b will be described. Reference numeral 33 denotes a gas-liquid separator. The upper part of the gas-liquid separator 33 is connected to the high-pressure on-off valves 41 a and 41 b, and the lower part of the gas-liquid separator 33 is connected to the first refrigerant heat exchanger 35. The other end of the first refrigerant heat exchanger 35 is connected to the check valves 39a and 39b and the second refrigerant heat exchanger 36 via the expansion device 34. The other end of the second refrigerant heat exchanger 36 is connected to check valves 40a and 40b connected to the expansion devices 3a and 3b of the load side unit. A refrigerant circuit (bypass circuit) branched from between the second refrigerant heat exchanger 36 and the check valves 40a and 40b is connected to the second refrigerant heat exchanger 36 and the first refrigerant via the expansion device 37. After being connected to the low pressure side of the heat exchanger 35, it is connected to the inlet of the low pressure pipe 104. Further, the gas side pipes of the load side heat exchangers 27a and 27b are connected to the upper pipe of the gas-liquid separator 33 via the high pressure on / off valves 41a and 41b, and low pressure via the low pressure on / off valves 42a and 42b. A tube 104 is also connected.

  The heat source side unit 51 and the load side units 52 a and 52 b are connected via a shunt controller 53. At this time, the heat source side unit 51 and the diversion controller 53 are connected by the high pressure pipe 103 and the low pressure pipe 104, and the diversion controller 53 and the load side units 52a and 52b are connected via the liquid pipe and the gas pipe.

  In the multi-system having this configuration, the flow of the refrigerant when the refrigerant amount is adjusted and the refrigerant is automatically charged as necessary will be described. In the operation mode, all indoor units are operated so as to perform cooling. At this time, when the compressor 1 is operated, the high-temperature and high-pressure gas refrigerant is condensed and vaporized in the heat source side heat exchanger 22 via the four-way valve 21 to be in a liquid state. However, the high-pressure pipe 103 has a large pipe diameter in consideration of the pressure loss during heating, and it is often impossible to enclose the refrigerant to the extent that the entire pipe is filled with liquid, so at the outlet of the condenser (heat source side heat exchanger 22). The refrigerant is not overcooled. In this case, the gas-liquid two-phase refrigerant containing some gas flows through the high-pressure pipe 103 and flows into the gas-liquid separator 33. The gas-liquid two-phase refrigerant that has flowed to the gas-liquid separator 33 flows from the lower part of the gas-liquid separator 33 to the first refrigerant heat exchanger 35, and is throttled to an intermediate pressure via the throttle device 34. It is cooled in the heat exchanger 36 until it is completely condensed. A part of the refrigerant is throttled to a low pressure via a throttle device 37, flows through the low pressure side of the second refrigerant heat exchanger 36 and the first refrigerant heat exchanger 35, and has an intermediate pressure gas-liquid two flowing through the high pressure side. It heat-exchanges with the phase refrigerant, evaporates and vaporizes itself, merges with the refrigerant flowing through the main circuit, and flows to the low pressure pipe 104. At this time, the expansion device 37 uses the temperature difference between the temperature sensor 44 installed at the inlet of the second refrigerant heat exchanger 36 and the temperature sensor 45 installed on the outlet side of the first refrigerant heat exchanger 35 to generate a refrigerant. The degree of superheat is detected and controlled so that the degree of superheat is constant. The remaining liquid refrigerant supercooled by the second refrigerant heat exchanger 36 flows to the load side unit via the check valves 40a and 40b. Then, the pressure is reduced to a low pressure by the expansion devices 11a and 11b, the heat is removed from the surroundings by the load side heat exchangers 27a and 27b, and the air is evaporated and vaporized. The flow returns to the heat source side unit 51. The gas refrigerant that has returned to the heat source side unit 51 returns to the compressor 1 via the check valve 32 b, the four-way valve 21, and the accumulator 23.

  A method of determining the shortage state of the refrigerant and automatically filling the refrigerant while performing such cooling operation will be described with reference to the flowchart of FIG. In FIG. 12, in a state where the refrigerant supply cylinder is connected to the refrigerant filling port 7, the operation for adjusting the refrigerant amount is started in STEP1. As a start trigger, a service switch provided in the outdoor unit, a remote controller, an external contact input, a control signal from a personal computer or the like is used. In STEP2, in order to take a control interval, the process waits until a predetermined time elapses, and proceeds to STEP3 after the predetermined time elapses. In STEP 3, the intermediate pressure Pm of the flow dividing controller 53 and the refrigerant temperature Trout in the second refrigerant heat exchanger 36 are detected. In STEP 4, the difference SC between the saturation temperature Tsat (Pm) of Pm and the outlet refrigerant temperature Trout of the second refrigerant heat exchanger 36 is calculated. In STEP5, the calculated SC is compared with the SCm of the target value. If SC ≧ SCm, the process proceeds to STEP6 and the refrigerant amount adjustment is finished. When SC <SCm, the routine proceeds to STEP 7, where the refrigerant filling on-off valve 6 is opened for a predetermined time, and the refrigerant is filled into the refrigerant circuit from the refrigerant supply cylinder through the refrigerant filling port 7. At the same time, the on-off valve 5 is opened. After filling the refrigerant at STEP 7 for a predetermined time, proceed to STEP 2.

  Next, the operation of the refrigeration air conditioner during normal air conditioning operation will be described. First, the cooling only operation in which all the load side units perform the cooling operation will be described. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 condenses in the heat source side heat exchanger 22 and then reaches the gas-liquid separator 33 in the diversion controller 53 via the check valve 32 a and the high-pressure pipe 103. The liquid refrigerant that has reached the gas-liquid separator 33 flows from the lower part of the gas-liquid separator 33 to the first refrigerant heat exchanger 35, and is squeezed to an intermediate pressure through the expansion device 34, and then the second refrigerant heat exchange. It is cooled by the vessel 36 to increase the degree of supercooling, and part of it reaches the load side units 52a and 52b via the check valves 40a and 40b. The liquid refrigerant reaching the load-side units 52a and 52b is throttled to a low pressure by the expansion devices 3a and 3b, flows into the load-side heat exchangers 27a and 27b as a low-temperature gas-liquid two-phase refrigerant, and takes heat from the surroundings. While cooling, it evaporates and vaporizes itself and flows to the low-pressure pipe 104 via the on-off valves 42a and 42b. On the other hand, the remaining liquid refrigerant whose degree of supercooling has been increased by the second refrigerant heat exchanger 36 is throttled by the expansion device 37 to become a low-temperature gas-liquid two-phase refrigerant and the second refrigerant heat exchanger 36 and the second refrigerant heat exchanger 36. The gas refrigerant that has flowed into the first refrigerant heat exchanger 35, exchanged heat with the liquid refrigerant that has flowed from the other flow path in the gas-liquid separator 33, and evaporated and vaporized, and evaporated and vaporized in the load-side heat exchangers 27a and 27b. And then flows through the low-pressure pipe 104 and returns to the compressor 1 via the check valve 32 b, the four-way valve 21 and the accumulator 23.

  Next, the cooling main operation in which the cooling operation and the heating operation are mixed and the cooling load is larger than the heating load will be described. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 is partially condensed in the heat source side heat exchanger 22 to become a high-temperature and high-pressure gas-liquid two-phase refrigerant, and then the check valve 32a and the high-pressure pipe 103 are connected. To the gas-liquid separator 33 in the diversion controller 53. Here, it is assumed that the load side unit 52a is in the heating operation and the load side unit 52b is in the cooling operation. The gas-liquid two-phase refrigerant reaching the gas-liquid separator 33 is separated from the gas refrigerant from the upper part of the gas-liquid separator 33 and flows to the load-side heat exchanger 27a via the on-off valve 41a to dissipate heat to the surroundings. While heating, it condenses and liquefies itself, is throttled to an intermediate pressure via the throttle device 3a, and returns to the diversion controller 53. The liquid refrigerant that has returned to the diversion controller 53 is separated by the gas-liquid separator 33, increases supercooling by the first refrigerant heat exchanger 35, and merges with the liquid refrigerant that has been throttled to the intermediate pressure by the throttling device 34. After the degree of supercooling is further increased by the second refrigerant heat exchanger 36, a part thereof flows to the load side unit 52 b via the check valve 40 b, and the remaining liquid refrigerant flows to the expansion device 37. The liquid refrigerant that has flowed to the load-side unit 52b is throttled to a low pressure by the expansion device 3b, becomes a low-temperature gas-liquid two-phase refrigerant, flows to the load-side heat exchanger 27b, takes heat from the surroundings, and cools itself. Evaporates and vaporizes, and flows to the low-pressure pipe 104 through the on-off valve 42b. On the other hand, the liquid refrigerant that has flowed to the expansion device 37 is throttled by the expansion device 37 and becomes a low-temperature gas-liquid two-phase refrigerant, and then flows to the second refrigerant heat exchanger 36 and the first refrigerant heat exchanger 35 to be gas-liquid. After heat exchange with the liquid refrigerant flowing from the separator 33 to evaporate / vaporize and merge with the gas refrigerant evaporated / vaporized in the load side heat exchanger 27b, the refrigerant flows through the check valve 32b, the four-way valve 21 and the accumulator 23. Return to Compressor 1.

  Next, the heating main operation in which the cooling operation and the heating operation are mixed and the heating load is larger than the cooling load will be described. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows to the high-pressure pipe 103 via the four-way valve 21 and the check valve 32 c and reaches the gas-liquid separator 33 in the branch controller 53. Here, it is assumed that the load side unit 52a is in the heating operation and the load side unit 52b is in the cooling operation. The high-temperature and high-pressure gas refrigerant that has reached the gas-liquid separator 33 flows from the upper part of the gas-liquid separator 33 to the load-side heat exchanger 27a via the on-off valve 41a, radiates heat to the surroundings, and heats itself. Is condensed and liquefied, throttled to an intermediate pressure via the throttle device 3a, and returned to the flow dividing controller 53. A part of the liquid refrigerant returned to the diversion controller 53 is cooled by the second refrigerant heat exchanger 36 and then flows to the load side unit 52b via the check valve 40b. The liquid refrigerant that has flowed to the load-side unit 52b is throttled to a low pressure by the expansion device 3b, becomes a low-temperature gas-liquid two-phase refrigerant, flows to the load-side heat exchanger 27b, takes heat from the surroundings, and cools itself. Evaporates and vaporizes, and flows to the low-pressure pipe 104 through the on-off valve 42b. The remaining liquid refrigerant returned to the diversion controller 53 is throttled to a low pressure by the expansion device 37, and then merged with the gas refrigerant evaporated and gas-liquid at the load side heat exchanger 52b, flows through the low pressure pipe 104, and a check valve. It evaporates and vaporizes in the heat source side heat exchanger 22 through 32d, and returns to the compressor 1 through the four-way valve 21 and the accumulator 23.

  Finally, the heating only operation in which all the load side units perform the heating operation will be described. The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows to the high-pressure pipe 103 via the four-way valve 21 and the check valve 32 c and reaches the gas-liquid separator 33 in the branch controller 53. The high-temperature and high-pressure gas refrigerant that has reached the gas-liquid separator 33 flows from the upper part of the gas-liquid separator 33 to the load-side heat exchangers 27a and 27b via the on-off valves 41a and 41b. At the same time, it condenses and liquefies itself, is throttled to an intermediate pressure via the throttle devices 3a and 3b, and returns to the diversion controller 53. The liquid refrigerant returned to the diversion controller 53 is throttled to a low pressure by the expansion device 37, and then merged with the gas refrigerant evaporated and vaporized by the load side heat exchanger 52b, flows through the low pressure pipe 104, and passes through the check valve 32d. Then, it evaporates and vaporizes in the heat source side heat exchanger 22 and returns to the compressor 1 through the four-way valve 21 and the accumulator 23.

  With the above-described configuration and operation, even in a system in which cooling and heating can be performed simultaneously with a two-tube type having a large high-pressure pipe 103, it is possible to appropriately determine the refrigerant and to perform automatic filling of the refrigerant when there is a shortage. . Further, even when the refrigerant is not supercooled by the heat source side heat exchanger 22, it is possible to accurately charge the refrigerant by determining an appropriate amount of refrigerant based on the degree of supercooling at the outlets of the refrigerant heat exchangers 35 and 36. Therefore, the refrigerant is not overfilled, and a highly reliable system can be obtained.

Embodiment 6 FIG.
FIG. 13 shows a refrigerant circuit diagram of a refrigerating and air-conditioning apparatus according to Embodiment 6 of the present invention. This apparatus includes a heat source side unit 51, load side units 52a and 52b, and diversion kits 54a and 54b.
The configuration of the heat source side unit 51 is as follows. Reference numeral 1 denotes a compressor, 22 denotes a heat source side heat exchanger, 23 denotes an accumulator, and 26 denotes an outdoor expansion device. The discharge pipe of the compressor 1 is connected to the heat source side heat exchanger 22 via the on-off valve 29b, and is branched in the middle to be connected to the high pressure pipe 103. The inflow pipe of the accumulator 23 is connected to the refrigerant circuit between the on-off valve 29b and the heat source side heat exchanger 22 via the on-off valve 29a, and is branched in the middle to be connected to the low-pressure pipe 104. The other end of the heat source side heat exchanger 22 is connected to the liquid pipe 101. Further, the pipe branched from the discharge pipe of the compressor 1 is joined to the refrigerant circuit between the four-way valve 21 and the accumulator 23 via the opening / closing valve 5, and the refrigerant filling opening / closing is performed between the junction and the opening / closing valve 5. A refrigerant charging port 7 is connected through the valve 6. Reference numeral 8 denotes a pressure sensor that detects pressure at the high-pressure portion on the discharge side of the compressor 1, and 9 denotes a first temperature sensor that detects the temperature of the refrigerant at the high-pressure portion on the discharge side of the compressor 1. These constitute the heat source unit 51.

  Next, the configuration of the load side unit will be described. 3a and 3b are expansion devices, and 27a and 27b are load-side heat exchangers. 11a and 11b are third temperature sensors for detecting the temperature of the refrigerant between the expansion devices 3a and 3b and the load side heat exchangers 27a and 27b, and 12a and 12b are load side heat exchangers 27a and 27b and a diversion kit 54a. , 54b is a fourth temperature sensor that detects the temperature of the refrigerant. These constitute load-side units 52a and 52b. The subscripts a and b indicate multi-type air conditioners to which a plurality of indoor units are connected.

  The heat source side unit 51 and the load side unit 52 configured as described above are connected to the heat source side heat exchanger 22 and the expansion devices 3a and 3b via the liquid pipe 101, and the load side heat exchangers 27a and 27b are connected to the diversion kit 54a. , 54b to the high pressure pipe 103 and the low pressure pipe 104. In the diversion kits 54a and 54b, the high-pressure pipe 103 and the load-side heat exchangers 27a and 27b are connected via the on-off valves 30a and 30b, and the low-pressure pipe 104 and the load-side heat exchange are connected via the on-off valves 31a and 31b. Devices 27a and 27b are connected.

  The flow of the refrigerant when the refrigerant amount is adjusted and the refrigerant is automatically charged as necessary in the multi-system having the above configuration will be described. The operation mode will be described first in the case where all the load side units perform cooling. At this time, when the compressor 1 is operated, the high-temperature and high-pressure gas refrigerant flows into the heat source side heat exchanger 22 via the on-off valve 29b, and is condensed and liquefied. The liquefied liquid refrigerant flows through the liquid pipe 101, flows to the load side units 52a and 52b, is throttled to a low pressure by the expansion devices 3a and 3b, and cools by taking heat from the surroundings by the load side heat exchangers 27a and 27b. , Itself evaporates and vaporizes, flows into the low-pressure pipe 104 via the on-off valves 31a and 31b, and returns to the heat source side unit 51. The gas refrigerant that has returned to the heat source unit 51 returns to the compressor 1 via the accumulator 23.

  Next, the operation when the operation mode is a mixture of cooling and heating and a large cooling load will be described. Here, it is assumed that the load side unit 52a performs heating and the load side unit 52b performs cooling. When the compressor 1 is operated, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows to the heat source side heat exchanger 22 through the on-off valve 29b and flows to the load side unit through the high pressure pipe 103. The gas refrigerant flowing to the heat source side heat exchanger 22 dissipates heat, condenses and liquefies, and the liquefied refrigerant is throttled to an intermediate pressure by the outdoor expansion device 26, flows through the liquid pipe 101, and flows toward the load side unit. . On the other hand, the gas refrigerant that has flowed through the high-pressure pipe 103 flows to the load-side heat exchanger 27a through the on-off valve 30a, dissipates heat to the surroundings, heats it, condenses and liquefies itself, and then expands to an intermediate pressure by the expansion device 3a. The liquid refrigerant that has flowed through the liquid pipe 101 and flows toward the load side unit 52b. The liquid refrigerant that has flowed to the load side unit 52b is throttled to a low pressure by the expansion device 3b, takes heat from the surroundings by the load side heat exchanger 27b, cools, and evaporates and vaporizes itself through the on-off valve 31b. It flows into the low pressure pipe 104 and returns to the heat source side unit 51 and returns to the compressor 1 via the accumulator 23.

  Next, the operation when the operation mode is a mixture of cooling and heating and a large heating load will be described. Here, it is assumed that the load side unit 52a performs heating and the load side unit 52b performs cooling. When the compressor 1 is operated, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 flows through the high-pressure pipe 103 toward the load side unit. The gas refrigerant that has flowed through the high-pressure pipe 103 flows to the load-side heat exchanger 27a via the on-off valve 30a, dissipates heat to the surroundings, heats it, condenses and liquefies itself, and then throttles to an intermediate pressure by the expansion device 3a. A part of the liquid refrigerant flows toward the load side unit 52 b, and the remaining liquid refrigerant flows through the liquid pipe 101 to the heat source side unit 51. The liquid refrigerant that has flowed to the load side unit 52b is throttled to a low pressure by the expansion device 3b, takes heat from the surroundings by the load side heat exchanger 27b, cools, and evaporates and vaporizes itself through the on-off valve 31b. It flows into the low pressure pipe 104 and returns to the heat source side unit 51. The liquid refrigerant that has flowed through the liquid pipe 101 and returned to the heat source side unit 51 is throttled to a low pressure by the outdoor expansion device 26, and is evaporated and vaporized by exchanging heat with the outside air by the heat source side heat exchanger 22. The gas refrigerant that has flowed through the low-pressure pipe 104 passes through and is returned to the compressor 1 through the accumulator 23.

  Next, a method of determining the refrigerant shortage and automatically charging the refrigerant during the cooling operation or the cooling main operation will be described with reference to the flowchart of FIG. In FIG. 14, in a state where the refrigerant supply cylinder is connected to the refrigerant filling port 7, the operation for adjusting the refrigerant amount is started in STEP1. As a start trigger, a service switch provided in the outdoor unit, a remote controller, an external contact input, a control signal from a personal computer or the like is used. In STEP2, in order to take a control interval, the process waits until a predetermined time elapses, and proceeds to STEP3 after the predetermined time elapses. In STEP 3, the discharge pressure Pd of the compressor 1 and the refrigerant temperature Tcout at the outlet of the heat source side heat exchanger 22 are detected. In STEP 4, the difference SC between the saturation temperature Tsat (Pd) of Pd and the refrigerant temperature Tcout at the outlet of the heat source side heat exchanger 22 is calculated. In STEP5, the calculated SC is compared with the SCm of the target value. If SC ≧ SCm, the process proceeds to STEP6 and the refrigerant amount adjustment is finished. When SC <SCm, the routine proceeds to STEP 7 where the refrigerant filling on-off valve 6 is opened for a predetermined time, and the refrigerant is filled into the refrigerant circuit from the refrigerant supply cylinder through the refrigerant filling port 7. At the same time, the on-off valve 5 is opened. After filling the refrigerant at STEP 7 for a predetermined time, proceed to STEP 2.

  With the above-described configuration and operation, even in a three-pipe refrigeration and air conditioning system that can be operated simultaneously with cooling and heating, the appropriate amount of refrigerant can be quickly determined and charged as necessary. Can be completed.

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 Condenser, 3, 3a, 3b Throttle device, 4 Evaporator, 5 On-off valve, 6 Refrigerant filling on-off valve, 7 Refrigerant filling port, 8 Pressure sensor, 9 1st temperature sensor, 10 2nd 11, 11a, 11b Third temperature sensor, 12, 12a, 12b Fourth temperature sensor, 13 Open / close valve, 14 Open / close valve, 15 Open / close valve, 16 Open / close valve, 17 Throttle device, 18 5th Temperature sensor, 19 On-off valve, 20 Second pressure sensor, 21 Four-way valve, 22 Heat source side heat exchanger, 23 Accumulator, 24 Refrigerant heat exchanger, 25 Recovery unit, 26 Outdoor expansion device, 27a, 27b Load side heat exchange 28, third pressure sensor, 29a, 29b on-off valve, 30a, 30b on-off valve, 31a, 31b on-off valve, 32a, 32b, 33c, 33d check valve, 33 gas-liquid Separator, 34 throttle device, 35 first refrigerant heat exchanger, 36 second refrigerant heat exchanger, 37 throttle device, 38 temperature sensor, 39a, 39b check valve, 40a, 40b check valve, 41a, 41b Open / close valve for high pressure, 42a, 42b Open / close valve for low pressure, 43 Pressure sensor, 44 Temperature sensor, 45 Temperature sensor, 46 Second throttle device, 51 Heat source side unit, 52a, 52b Load side unit, 53 Split flow controller, 54 Split flow Kit, 101 liquid pipe, 102 gas pipe, 103 high pressure pipe, 104 low pressure pipe.

Claims (9)

A refrigerating and air-conditioning apparatus comprising at least a compressor, a condenser, a throttling device and an evaporator,
A hot gas bypass circuit branched from the discharge side of the compressor and connected to a refrigerant circuit on the suction side of the compressor via an opening / closing means;
A refrigerant charging port connected via a refrigerant charging switch between the opening / closing means on the hot gas bypass circuit and the connecting portion of the refrigerant circuit on the compressor suction side ;
I have a,
The difference SC between the saturation temperature of the discharge pressure of the compressor and the refrigerant temperature at the condenser outlet is calculated, and the calculated SC is compared with the SCm of the target value. When SC <SCm, the switching means A refrigerating and air-conditioning apparatus, wherein both the refrigerant charging switch are opened .   The refrigerant charging switch is configured to be capable of adjusting the flow rate, and the refrigerant charging switch is configured so that at least one of the superheat degree of the refrigerant discharged from the compressor or the superheat degree of the suction refrigerant has a predetermined value. 2. The refrigerating and air-conditioning apparatus according to claim 1, wherein the flow rate of the refrigerant flowing from the switch is controlled.   When there is no change in the degree of supercooling of the outlet refrigerant of the condenser for a predetermined time, a signal indicating that the refrigerant supply cylinder connected to the refrigerant charging port is empty is issued to the outside. The refrigeration air conditioner according to any one of claims 1 to 2. A heat source side unit including at least a compressor, a heat source side heat exchanger, and a four-way valve; and a load side unit including at least a throttle device and a load side heat exchanger, the heat source side unit and the load side unit. A refrigerating and air-conditioning apparatus connected by refrigerant piping,
A hot gas bypass circuit branched from the discharge side of the compressor and connected to a refrigerant circuit on the suction side of the compressor via an opening / closing means;
A refrigerant charging port connected via a refrigerant charging switch between the opening / closing means on the hot gas bypass circuit and the connecting portion of the refrigerant circuit on the compressor suction side ;
I have a,
The difference SC between the saturation temperature of the discharge pressure of the compressor and the refrigerant temperature at the condenser outlet is calculated, and the calculated SC is compared with the SCm of the target value. When SC <SCm, the switching means A refrigerating and air-conditioning apparatus, wherein both the refrigerant charging switch are opened . A heat source side unit composed of at least a compressor, a heat source side heat exchanger, a four-way valve and a check valve; a load side unit composed of at least a throttling device and a load side heat exchanger; at least a gas-liquid separator; And a shunt controller having a circuit for bypassing from the liquid part to the low pressure part via a bypass throttling device, and switching the heat source side unit and the load side unit via the shunt controller. A refrigeration air conditioner connected by two refrigerant pipes,
A hot gas bypass circuit branched from the discharge side of the compressor and connected to a refrigerant circuit on the suction side of the compressor via an opening / closing means;
A refrigerant charging port connected via a refrigerant charging switch between the opening / closing means on the hot gas bypass circuit and the connecting portion of the refrigerant circuit on the compressor suction side ;
I have a,
The difference SC between the saturation temperature of the discharge pressure of the compressor and the refrigerant temperature at the condenser outlet is calculated, and the calculated SC is compared with the SCm of the target value. When SC <SCm, the switching means A refrigerating and air-conditioning apparatus, wherein both the refrigerant charging switch are opened . At least a compressor, a heat source side heat exchanger, a heat source side unit composed of a four-way valve and a heat source side expansion device, and a load side unit composed of at least a load side expansion device and a load side heat exchanger,
The heat source side unit and the load side unit are connected to the heat source side heat exchanger and the load side heat exchanger so as to be able to switch between a high pressure pipe and a low pressure pipe via a diversion kit, and the heat source is connected by a liquid pipe. A refrigerating and air-conditioning apparatus formed by connecting a side throttle device and the load side throttle device,
A hot gas bypass circuit branched from the discharge side of the compressor and connected to a refrigerant circuit on the suction side of the compressor via an opening / closing means;
A refrigerant charging port connected via a refrigerant charging switch between the opening / closing means on the hot gas bypass circuit and the connecting portion of the refrigerant circuit on the compressor suction side ;
I have a,
The difference SC between the saturation temperature of the discharge pressure of the compressor and the refrigerant temperature at the condenser outlet is calculated, and the calculated SC is compared with the SCm of the target value. When SC <SCm, the switching means A refrigerating and air-conditioning apparatus, wherein both the refrigerant charging switch are opened . The refrigerating and air-conditioning according to any one of claims 1 to 6 , wherein the suction side of the compressor is a refrigerant suction path or a refrigerant discharge path of an accumulator connected to the suction side of the compressor. apparatus. A refrigerating and air-conditioning apparatus comprising at least a compressor, a condenser, a throttling device, and an evaporator, the hot branching off from the discharge side of the compressor and connected to a refrigerant circuit on the suction side of the compressor via an opening / closing means A gas bypass circuit, and a refrigerant charging port connected via a refrigerant charging switch between the opening / closing means on the hot gas bypass circuit and the connection portion of the refrigerant circuit on the compressor suction side , A refrigerant charging method of a refrigeration air conditioner provided,
The difference SC between the saturation temperature of the discharge pressure of the compressor and the refrigerant temperature at the outlet of the condenser is calculated, and the calculated SC is compared with the SCm of the target value. When SC <SCm,
Wherein the refrigerant discharged from the compressor, while returning to the suction side of the compressor through the switching means, between the suction side of the compressor and the switching means, via the refrigerant charging switching device A refrigerant charging method for a refrigerating and air-conditioning apparatus, wherein the refrigerant is charged from a refrigerant charging port. The refrigerant charging switch is adjustable in flow rate, and the refrigerant charging switch is configured so that at least one of the superheat degree of the refrigerant discharged from the compressor or the superheat degree of the suction refrigerant has a predetermined value. The refrigerant charging method according to claim 8 , wherein the flow rate of the refrigerant flowing from the refrigerant is controlled.

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