JP2012007856A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioner in which refrigerant in a refrigerant adjustor can be rapidly filled to a refrigerant circuit.SOLUTION: The air conditioner includes: a heat source side heat exchanger 200; a user side heat exchanger 201; an expansion valve 221 disposed on a position of a downstream side of the heat source side heat exchanger 200 and an upstream side of the user side heat exchanger 201 and throttling and expanding a refrigerant; a compressor 100 disposed on a position of an upstream side of the heat source side heat exchanger 200 and a downstream side of the user side heat exchanger 201; a refrigerant adjustor 61 in which a refrigerant is stored; an inlet pipe 62 branched from a discharge side pipe 110 of the compressor 100, connected to the refrigerant adjustor 61, and introducing the refrigerant discharged from the compressor 100 to the refrigerant adjustor 61; and an outlet pipe 63 connected to a pipe connecting the expansion valve 221 and the user side heat exchanger 201, and leading out the refrigerant stored in the refrigerant adjustor 61 to the pipe.

Description

  The present invention relates to an air conditioner including a refrigerant regulator for filling a refrigerant circuit with a refrigerant.

  In order to start the trial operation after installing the air conditioner on site, it is necessary to fill the refrigerant circuit of the air conditioner with the refrigerant. Patent Document 1 discloses a technique for performing a refrigerant charging operation using a cylinder. There is also known an air conditioner that does not require a filling operation by a cylinder by providing a refrigerant regulator that is a tank filled with a refrigerant in the refrigerant circuit of the air conditioner in advance.

  In a conventional air conditioner including the refrigerant regulator, an inlet pipe branched from the discharge side pipe of the compressor and a lead-out pipe connected to a liquid pipe through which the condensed liquid refrigerant passes are connected to the refrigerant regulator. By doing so, the refrigerant in the refrigerant regulator is filled in the refrigerant circuit. That is, the high-pressure gas refrigerant discharged from the compressor is introduced into the refrigerant regulator through the introduction pipe. The refrigerant in the refrigerant regulator pressurized by the high-pressure gas refrigerant is led out to the outlet pipe and flows into the liquid pipe to which the outlet pipe is connected. Thereby, the refrigerant in the refrigerant regulator is filled in the refrigerant circuit.

JP 2007-198642 A

  However, since the liquid refrigerant flowing through the liquid pipe is high in pressure, the pressure in the refrigerant regulator is slightly higher than the pressure of the liquid refrigerant inside the liquid pipe even with pressurization by the high-pressure gas refrigerant. I can only do it. Therefore, it takes a long time until the refrigerant in the refrigerant regulator is completely charged in the refrigerant circuit, and it takes a long time until the refrigerant charging becomes rate-limiting and the trial operation is started.

  The present invention has been made to solve such problems, and an object thereof is to provide an air conditioner that can quickly fill the refrigerant circuit with the refrigerant in the refrigerant regulator.

  The air conditioner of the present invention includes a heat source side heat exchanger (200), a use side heat exchanger (201), and the use side heat exchanger (201) on the downstream side of the heat source side heat exchanger (200). ) Upstream of the heat source side heat exchanger (200) on the upstream side of the heat source side heat exchanger (200) and on the downstream side of the use side heat exchanger (201). , A compressor (100) provided in the refrigerant, a refrigerant regulator (61) in which refrigerant is stored, and a discharge side pipe (110) of the compressor (100) branched to connect to the refrigerant regulator (61) And connecting the introduction pipe (62) for introducing the refrigerant discharged from the compressor (100) to the refrigerant regulator (61), the expansion valve (221) and the use side heat exchanger (201). It is connected to a pipe (25), and the refrigerant regulator ( Includes a lead pipe for deriving the refrigerant stored in 1) (63), the.

  In this configuration, unlike the conventional case where the refrigerant in the refrigerant regulator (61) is led to the liquid pipe through which the high-pressure liquid refrigerant after condensation passes, the expansion valve (221) and the use side heat exchanger are extracted. The refrigerant in the refrigerant regulator (61) is led out to the pipe (25) connecting to (201), that is, the pipe (25) through which the low-pressure refrigerant after expansion of the expansion valve (221) flows. Therefore, the difference between the pressure in the refrigerant regulator (61) and the pressure in the pipe from which the refrigerant is led out (pressure in the pipe (25)) can be increased as compared with the conventional one. It becomes possible to quickly fill the refrigerant circuit with the refrigerant in (61).

  The air conditioner is provided in at least one of the introduction pipe (62) and the outlet pipe (63), and leads out the refrigerant stored in the refrigerant regulator (61) to the pipe (25). It is preferable to further include a flow rate adjusting mechanism for adjusting the amount and a control unit (11) for controlling the flow rate adjusting mechanism.

  In this configuration, the control unit (11) controls the flow rate adjusting mechanism and adjusts the amount of the refrigerant led to the pipe (25), so that liquid compression occurs in the compressor (100), and compression is performed. It can suppress that a malfunction arises in a machine (100).

  In addition, as the flow rate adjusting mechanism, for example, a motor-operated valve (631) provided in the outlet pipe (63) and having an adjustable opening can be used.

  The controller (11) further includes a wetness calculation unit (13) that calculates a wetness degree that is a ratio of the liquid refrigerant contained in the refrigerant flowing into the suction part of the compressor (100), and the control unit (11) includes the wetness degree. It is preferable to determine the opening degree of the motor-operated valve (631) based on According to this structure, the effect which suppresses that a liquid compression generate | occur | produces in the said compressor (100) and a malfunction arises in a compressor (100) can be heightened more.

  In addition, for example, a temperature detection unit (111) that detects the temperature of the discharge gas of the compressor (100) is further provided, and the wetness calculation unit (13) calculates the wetness based on the temperature of the discharge gas. It can be calculated. According to this configuration, the wetness can be easily calculated.

  According to the air conditioner according to the present invention, in the filling operation of filling the refrigerant into the refrigerant circuit, a troublesome cylinder operation is not necessary, and the refrigerant in the refrigerant regulator can be quickly filled into the refrigerant circuit. The time required for the filling operation, which has been rate-controlled in the above, can be shortened, and the trial run time can be shortened.

It is a schematic block diagram which shows the air conditioner which concerns on Embodiment 1 of this invention. It is a functional block diagram which shows schematic structure of the control system and main mechanism of the air conditioner which concern on Embodiment 1 of this invention. It is a Mollier diagram (pressure-specific enthalpy diagram, ph diagram) showing a refrigeration cycle in the refrigerant circuit of the air conditioner according to Embodiment 1 of the present invention. It is a flowchart which shows the detail of refrigerant | coolant filling in the air conditioner which concerns on Embodiment 1 of this invention. It is a schematic block diagram which shows the air conditioner which concerns on Embodiment 2 of this invention.

<Embodiment 1>
Hereinafter, the air conditioner 101 which concerns on Embodiment 1 of this invention is demonstrated with reference to drawings. As shown in FIG. 1, the air conditioner 101 includes a heat source unit (outdoor unit) 102 and a utilization unit (indoor unit) 103. As shown in FIG. 1, the heat source unit 102 and the utilization unit 103 are connected to each other via a liquid refrigerant communication pipe 2 and a gas refrigerant communication pipe 3. In this air conditioner 101, the cooling operation and the heating operation can be switched by switching the refrigerant path in a four-way switching valve 230 described later.

  The air conditioner 101 can be used, for example, as an air conditioner for updating for updating existing heat source units and / or utilization units. The air conditioner 101 can quickly fill a refrigerant circuit with a refrigerant in a refrigerant regulator 61 described later at the time of updating. In the air conditioner 101 of the present embodiment, when the refrigerant circuit is filled with the refrigerant at the time of renewal, the refrigerant is in a state where the four-way switching valve 230 is set to the path shown by the solid line in FIG. Filling is performed.

  The usage unit 103 supplies air to the usage-side heat exchanger 201, the expansion valve 221, the usage-unit liquid refrigerant piping 25, the usage-unit gas refrigerant piping 27, and the usage-side heat exchanger 201 that function as an evaporator during cooling operation. A fan 214 for sending is provided. The liquid refrigerant pipe 25 is connected to the liquid refrigerant communication pipe 2 via the closing valve 24. The gas refrigerant pipe 27 is connected to the gas refrigerant communication pipe 3 via the closing valve 34.

  The expansion valve 221 is a motor-operated valve that is provided in the utilization unit internal liquid refrigerant pipe 25 and that can freely adjust the opening. The use side heat exchanger 201 is, for example, a cross fin type fin-and-tube heat exchanger.

  The heat source unit 102 includes a compressor 100, a heat source side heat exchanger 200 that functions as a condenser during cooling operation, a liquid pipe motor operated valve 220, a liquid refrigerant pipe 20 in the heat source unit, a gas refrigerant pipe 30 in the heat source unit, and a supercooled refrigerant pipe. 40, a bypass pipe 50, a pressure regulating valve 51 (first liquid refrigerant escape mechanism), a liquid refrigerant filling mechanism 60, a second liquid refrigerant relief mechanism 70, a refrigerant regulator 61, a controller 10, and the like.

  The compressor 100 is, for example, an inverter-controlled scroll compressor that is driven so that its capacity can be adjusted by changing the drive frequency. The compressor 100 compresses the low-pressure gas refrigerant until the pressure becomes equal to or higher than the critical pressure (for example, point A to point B in FIG. 3).

  As shown in FIG. 2, the controller 10 includes a control unit 11, a storage unit 12, and a wetness degree calculation unit 13. The controller 10 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), and the like.

  The control unit 11 controls the driving frequency of the compressor 100, the opening / closing of each electromagnetic valve described later, the opening degree of each motor operated valve described later, and the like based on the measurement value measured by each sensor described later The refrigeration cycle in the refrigerant circuit to which the heat source unit 102 is connected is controlled.

  The storage unit 12 stores in advance a control program for the heat source unit 102 and the like, and appropriately stores measurement values measured by the sensors.

  The wetness calculation unit 13 calculates the wetness that is the ratio of the liquid refrigerant contained in the refrigerant flowing into the compressor 100 based on the temperature of the discharge gas of the compressor 100 detected by the discharge temperature sensor 111 described later. Details of the calculation of the wetness by the wetness calculator 13 will be described later.

  As shown in FIG. 1, the compressor 100 is connected to one end of a discharge-side pipe 110 through which compressed high-pressure gas refrigerant is discharged, and the low-pressure gas evaporated in the use-side heat exchanger 201 of the use unit 103. One end of a suction side pipe 120 for sucking refrigerant is connected. The other end of the discharge side pipe 110 is connected to the first port of the four-way switching valve 230. The other end of the suction side pipe 120 is connected to the second port of the four-way switching valve 230. The third port of the four-way switching valve 230 is connected to the gas refrigerant pipe 30, and the fourth port is connected to the heat source side heat exchanger 200 via the refrigerant pipe.

  The four-way switching valve 230 includes a state in which the first port and the fourth port communicate with each other, and a state in which the second port and the third port communicate with each other (state indicated by a solid line in FIG. 1), and the first port And the third port communicate with each other, and the second port and the fourth port communicate with each other (state indicated by a broken line in FIG. 1). The switching operation of the four-way switching valve 230 reverses the refrigerant circulation direction in the refrigerant circuit.

  The discharge side pipe 110 of the compressor 100 is provided with a discharge temperature sensor 111 and a discharge pressure sensor 112. The discharge temperature sensor 111 detects the temperature of the high-pressure gas refrigerant after being compressed by the compressor 100. The discharge pressure sensor 112 detects the pressure of the high-pressure gas refrigerant after being compressed by the compressor 100.

  A suction temperature sensor 121 and a suction pressure sensor 122 are provided in the suction side pipe 120 of the compressor 100. The suction temperature sensor 121 detects the temperature of the low-pressure gas refrigerant sucked into the compressor 100. The suction pressure sensor 122 detects the pressure of the low-pressure gas refrigerant sucked into the compressor 100.

  The heat source side heat exchanger 200 is, for example, a cross fin type fin-and-tube heat exchanger. A heat source side heat exchanger temperature sensor 22 is provided in an intermediate path of the heat source side heat exchanger 200.

  The heat source unit 102 includes a fan 210 that blows outside air toward the heat source side heat exchanger 200. Heat exchange is performed between the outside air blown to the heat source side heat exchanger 200 and the refrigerant flowing through the heat source side heat exchanger 200 (for example, from point B to point C in FIG. 3 during cooling operation, and during heating operation) Point E to point A) in FIG. The fan 210 is rotationally driven by a fan motor (not shown). An outside air temperature sensor 211 for measuring the outside air temperature is provided at a position downstream of the airflow generated by the fan 210.

  The liquid pipe motor-operated valve 220 is an electric valve provided in the liquid refrigerant pipe 20 and having an adjustable opening degree. In the cooling operation in which the heat source side heat exchanger 200 functions as a condenser, the liquid pipe electric valve 220 adjusts the flow rate of the high-pressure gas refrigerant that is discharged from the compressor 100 and flows into the heat source side heat exchanger 200. . Further, in the heating operation in which the heat source side heat exchanger 200 functions as an evaporator, the liquid pipe motor operated valve 220 squeezes and expands the high-pressure liquid refrigerant after condensation in the use side heat exchanger 201 to heat the heat source side heat. It flows into the exchanger 200.

  Based on the temperature detected by the heat source side heat exchanger temperature sensor 22, the controller 11 converts the refrigerant saturation pressure in the heat source side heat exchanger 200 into a predetermined pressure so that the saturation pressure becomes a predetermined pressure. The opening degree of the valve 220, the driving frequency of the compressor 100, the rotational speed of the fan motor, and the like are determined.

  The heat source unit internal liquid refrigerant pipe 20 connects the heat source side heat exchanger 200 and the liquid refrigerant communication pipe 2. The liquid refrigerant pipe 20 and the liquid refrigerant communication pipe 2 are connected via a closing valve 21. A supercooling heat exchanger 42 is provided between the liquid pipe motor operated valve 220 and the closing valve 21 of the liquid refrigerant pipe 20. The supercooling heat exchanger 42 is, for example, a plate heat exchanger, and exchanges heat between the refrigerant flowing through the below-described supercooling refrigerant pipe 40 and the liquid refrigerant flowing through the liquid refrigerant pipe 20.

  The gas refrigerant pipe 30 in the heat source unit connects the gas refrigerant communication pipe 3 to the suction side pipe 120 or the discharge side pipe 110 via the four-way switching valve 230. The gas refrigerant pipe 30 and the gas refrigerant communication pipe 3 are connected via a closing valve 31.

  The shut-off valve 21 and the shut-off valve 31 in the heat source unit 102 are closed so that the refrigerant inside the heat source unit 102 does not leak until the heat source unit 102 is brought into the field and the heat source unit 102 is connected to the existing refrigerant circuit. ing. Similarly, the closing valve 24 and the closing valve 34 in the usage unit 103 do not leak the refrigerant inside the usage unit 103 until the usage unit 103 is carried into the field and the usage unit 103 is connected to the existing refrigerant circuit. So closed.

  The supercooling refrigerant pipe 40 is branched from a portion of the liquid refrigerant pipe 20 located between the liquid pipe motor operated valve 220 and the closing valve 21, passes through the supercooling heat exchanger 42, and is connected to the suction side pipe 120. ing. The supercooling refrigerant pipe 40 includes a supercooling liquid pipe electric valve 41 at a position upstream of the supercooling heat exchanger 42 in the flow direction of the refrigerant flowing in the supercooling refrigerant pipe 40.

  The supercooled liquid pipe motor operated valve 41 squeezes and expands the liquid refrigerant branched from the liquid refrigerant pipe 20. The liquid refrigerant whose temperature has decreased due to the expansion of the throttle flows into the supercooling heat exchanger 42. The liquid refrigerant flowing through the liquid refrigerant pipe 20 is cooled by exchanging heat between the liquid refrigerant flowing through the supercooling refrigerant pipe 40 and the supercooling heat exchanger 42 (for example, from point C in FIG. 3). Point D). By increasing the degree of supercooling of the liquid refrigerant flowing through the liquid refrigerant pipe 20, the efficiency of the refrigeration cycle is improved.

  The bypass pipe 50 is branched from the liquid refrigerant pipe 20 (between the supercooling heat exchanger 42 and the liquid pipe electric valve 220 in this embodiment), and the supercooling heat exchanger 42 and the supercooling liquid of the supercooling refrigerant pipe 40. It is connected to a portion between the pipe motor operated valve 41. In the present embodiment, the branch portion of the bypass pipe 50 from the liquid refrigerant pipe 20 is common to the supercooled refrigerant pipe 40. Since the supercooling refrigerant pipe 40 is connected to the suction side pipe 120, the bypass pipe 50 is a pipe that bypasses the liquid refrigerant in the liquid refrigerant pipe 20 to the suction side pipe 120.

  In the present embodiment, the end of the bypass pipe 50 is connected to a position between the supercooling heat exchanger 42 and the supercooled liquid pipe motor operated valve 41 in the supercooled refrigerant pipe 40 instead of the suction side pipe 120, The supercooling heat exchanger 42 is caused to function as a buffer for storing the liquid refrigerant released to the bypass pipe 50.

  The bypass pipe 50 is provided with a pressure adjustment valve 51. The pressure regulating valve 51 is a valve that is opened at a pressure exceeding a predetermined reference pressure value. When the control unit 11 stops the operation of the compressor 100, the refrigerant circulation in the refrigerant circuit stops, so that the liquid refrigerant is enclosed in the liquid refrigerant communication pipe 2. At this time, the temperature of the encapsulated liquid refrigerant gradually increases until it becomes equal to the outside air temperature due to heat conduction in the liquid refrigerant communication pipe 2. As the temperature rises, the liquid refrigerant expands in the liquid refrigerant communication pipe 2 and the pressure in the liquid refrigerant communication pipe 2 increases. In this way, when the pressure in the liquid refrigerant communication pipe 2 rises and exceeds the reference pressure value, the pressure adjustment valve 51 causes the liquid refrigerant release mechanism (first liquid) to release the liquid refrigerant from the liquid refrigerant communication pipe 2. It functions as a refrigerant escape mechanism.

  The air conditioner 101 includes a second liquid refrigerant escape mechanism 70. The second liquid refrigerant escape mechanism 70 is for allowing the liquid refrigerant in the liquid refrigerant communication pipe 2 to escape from the liquid refrigerant communication pipe 2. The second liquid refrigerant escape mechanism 70 includes a refrigerant regulator 61, a liquid refrigerant branch pipe 72, and a suction side connection pipe 73.

  The refrigerant regulator 61 is a tank capable of storing refrigerant. For example, if the working refrigerant (for example, R410A) filled in the refrigerant circuit after the heat source unit 102 is updated is stored in the refrigerant regulator 61 in advance, the cylinder work for filling the refrigerant when the heat source unit is updated becomes unnecessary. .

  The liquid refrigerant branch pipe 72 is branched from the liquid refrigerant pipe 20 and connected to the refrigerant regulator 61. One end of the liquid refrigerant branch pipe 72 connected to the refrigerant regulator 61 is located above the liquid level of the liquid refrigerant stored in the refrigerant regulator 61.

  The suction side connection pipe 73 is connected to a lead-out pipe 63 described later. One end of the suction side connection pipe 73 is connected to the upper part of the refrigerant regulator 61, and the other end is connected to the outlet pipe 63. The outlet pipe 63 is connected to the liquid refrigerant pipe 25 of the usage unit 103. One end of the suction side connection pipe 73 connected to the refrigerant regulator 61 is positioned above the liquid level of the liquid refrigerant stored in the refrigerant regulator 61.

  When the liquid refrigerant sealed in the liquid refrigerant communication pipe 2 is heated and expanded after the compressor 100 is stopped, even if the pressure of the liquid refrigerant is less than the reference pressure value of the pressure regulating valve 51, The liquid refrigerant is guided to the refrigerant regulator 61. The reason is as follows.

  That is, the suction-side connection pipe 73 is connected to the liquid refrigerant pipe 25 through which the low-pressure liquid refrigerant throttled and expanded from the expansion valve 221 in the usage unit 103 flows via the outlet pipe 63. The pressure is lower than the pressure inside the liquid refrigerant communication pipe 2. Therefore, due to the pressure difference between the pressure inside the liquid refrigerant communication pipe 2 and the pressure inside the refrigerant regulator 61, the liquid refrigerant inside the liquid refrigerant communication pipe 2 passes through the liquid refrigerant pipe 20 and the liquid refrigerant branch pipe 72. Is sucked into. As described above, since the air conditioner 101 includes the second liquid refrigerant escape mechanism 70, the operating frequency of the pressure regulating valve 51 can be reduced, and the liquid refrigerant can be prevented from being guided to the suction side pipe 120. . As a result, it is possible to reduce the possibility that the compressor 100 enters a liquid compression state when air conditioning is resumed.

  The liquid refrigerant branch pipe 72 includes a liquid refrigerant branch pipe electromagnetic valve 721. The suction side connection pipe 73 includes a suction side connection pipe solenoid valve 731. The control unit 11 controls the opening and closing of the electromagnetic valve 721 and the electromagnetic valve 731 as follows when the compressor 100 is shifted from the operating state to the stopped state.

  When the air-conditioning operation is stopped, the control unit 11 stops power supply to the motor that drives the compressor 100 and closes the electromagnetic valve 721 in order to shift the compressor 100 from the operating state to the stopped state. The first control for opening the electromagnetic valve 731 is started. In the first control, the refrigerant regulator 61 communicates only with the liquid refrigerant pipe 25 of the usage unit 103. Even if the control unit 11 stops supplying power to the motor for driving the compressor 100, the rotation of the compressor 100 does not stop immediately, and the refrigerant circulates in the refrigerant circuit. The inside becomes a low pressure, and the liquid refrigerant pipe 25 of the use unit 103 that communicates with the suction side pipe 120 and the inside of the refrigerant regulator 61 that communicates with the liquid refrigerant pipe 25 are decompressed.

  When a predetermined set time has elapsed, the control unit 11 ends the first control, and performs the second control to open the liquid refrigerant branch piping solenoid valve 721 and close the suction side connection piping solenoid valve 731. Start. In the second control, the refrigerant regulator 61 communicates only with the liquid refrigerant pipe 20 in the heat source unit that communicates with the liquid refrigerant communication pipe 2.

  Since the inside of the refrigerant regulator 61 is depressurized in the first control, the liquid refrigerant sealed in the liquid refrigerant communication pipe 2 is a pressure between the pressure inside the liquid refrigerant communication pipe 2 and the pressure inside the refrigerant regulator 61. Due to the difference, the refrigerant is sucked into the refrigerant regulator 61 and escaped from the liquid refrigerant communication pipe 2. The amount by which the liquid refrigerant is released from the liquid refrigerant communication pipe 2 is determined by the degree of decompression inside the refrigerant regulator 61, and the degree of decompression is determined by the duration of the first control. Therefore, the set time is set on the assumption that the amount of liquid refrigerant to be escaped is maximum, that is, when the pipe length of the liquid refrigerant communication pipe 2 is maximum and the expected outside air temperature is maximum. Is done.

  Note that if the refrigerant is excessively released to the refrigerant regulator 61 while the air conditioning is stopped, the efficiency of the refrigeration cycle is reduced when the air conditioning is resumed. In this embodiment, the time for the second control is also determined in advance. The controller 11 closes both the liquid refrigerant branch piping solenoid valve 721 and the suction side connection piping solenoid valve 731 after the end of the second control.

  The liquid refrigerant filling mechanism 60 is for filling the refrigerant circuit with the refrigerant stored in the refrigerant regulator 61 during the update. Further, when the operation of the compressor 100 is resumed and the refrigerant circulation is resumed in the refrigerant circuit, the liquid refrigerant charging mechanism 60 is released from the liquid refrigerant communication pipe 2 when the refrigerant circulation is stopped, and is supplied to the refrigerant regulator 61. It also functions as a mechanism for recirculating the stored refrigerant to the liquid refrigerant pipe 25 of the usage unit 103.

  The liquid refrigerant charging mechanism 60 includes a refrigerant regulator 61, an introduction pipe 62, an outlet pipe 63, an inlet pipe electromagnetic valve 621, and an outlet pipe electric valve 631 as a flow rate adjusting mechanism. The refrigerant regulator 61 is shared with the second liquid refrigerant escape mechanism 70.

  The introduction pipe 62 is branched from the discharge side pipe 110 and connected to the refrigerant regulator 61. One end of the introduction pipe 62 connected to the refrigerant regulator 61 is located above the liquid level of the liquid refrigerant stored in the refrigerant regulator 61. In the present embodiment, the introduction pipe 62 and the liquid refrigerant branch pipe 72 are connected to each other before being connected to the refrigerant regulator 61 and are combined into one pipe and connected to the refrigerant regulator 61. The introduction pipe solenoid valve 621 is provided in the introduction pipe 62 at a position upstream of the connection portion to the liquid refrigerant branch pipe 72.

  The outlet pipe 63 connects the refrigerant regulator 61 and the liquid refrigerant pipe 25 of the usage unit 103. One end of the outlet pipe 63 connected to the refrigerant regulator 61 is located below the liquid level of the liquid refrigerant stored in the refrigerant regulator 61. The outlet pipe 63 is provided with a outlet pipe electric valve 631.

  When the control unit 11 opens the inlet piping electromagnetic valve 621 to start filling the refrigerant into the refrigerant circuit, the high-pressure gas refrigerant discharged from the compressor 100 is guided to the refrigerant regulator 61, and the refrigerant regulator 61. The liquid refrigerant stored in is pressurized. The pressurized liquid refrigerant is pushed out from the refrigerant regulator 61 to the outlet pipe 63, and an amount corresponding to the opening degree of the outlet pipe electric valve 631 flows into the liquid refrigerant pipe 25 of the utilization unit 103 through the outlet pipe 63.

  In order to prevent liquid compression of the compressor 100, the wetness calculation unit 13 calculates the wetness of the suction unit of the compressor 100 based on the discharge gas temperature measured by the discharge temperature sensor 111, and the control unit 11 The opening degree of the motor-operated valve 631 is controlled so that the wetness does not exceed a predetermined value.

  Next, details of refrigerant charging including calculation of the wetness by the wetness calculation unit 13 and opening degree control of the electric valve 631 by the control unit 11 will be described.

  When the refrigerant filling of the refrigerant circuit is started, the liquid refrigerant flows into the liquid refrigerant pipe 25 of the utilization unit 103 through the outlet pipe 63 and joins the refrigerant expanded and squeezed in the expansion valve 221. These merged liquid refrigerants evaporate in the use side heat exchanger 201 located downstream thereof, and are sent to the compressor 100 through the gas refrigerant pipe 27 and the gas refrigerant pipe 30.

  In the present embodiment, at the time of the update, the liquid refrigerant stored in the refrigerant regulator 61 is caused to flow into the liquid refrigerant pipe 25 between the expansion valve 221 and the use side heat exchanger 201 in the use unit 103. The amount of liquid refrigerant flowing into the side heat exchanger 201 is greater than that during normal cooling operation. Therefore, the state of the refrigerant sucked into the compressor 100 may change to the wet steam side as compared with the normal cooling operation (for example, from point A to point A ′ in FIG. 3).

  The wetness calculation unit 13 calculates the wetness based on the temperature (superheat degree) of the gas refrigerant (discharge gas) discharged from the compressor 100 measured by the discharge temperature sensor 111.

  The saturation temperature when the discharge gas becomes saturated vapor (point S) is unique to the pressure of the discharge gas, and can be calculated from the pressure measured by the discharge pressure sensor 112. Therefore, the degree of superheat of the discharge gas can be calculated by obtaining the difference between the temperature of the discharge gas measured by the discharge temperature sensor 111 and the saturation temperature.

  When the refrigerant sucked into the compressor 100 is saturated vapor (point As), the superheat degree SHs of the discharge gas is determined by the refrigerant temperature measured by the suction temperature sensor 121 and the refrigerant pressure measured by the suction pressure sensor 122 being the saturation temperature. Since it is equal to the saturation pressure, it can be calculated using both values.

  The state of the refrigerant sucked into the compressor 100 is superheated steam if the superheat degree of the discharge gas is larger than SHs, and is wet steam if the superheat degree of the discharge gas is smaller than SHs. Refrigerant charging into the refrigerant circuit is started, the liquid refrigerant in the refrigerant regulator 61 is led out to the liquid refrigerant pipe 25 of the utilization unit 103, and the state of the refrigerant sucked into the compressor 100 changes from superheated steam to wet steam. And the case where it changes. In this case, the state of the discharge gas changes from the point B to the point B ', and the degree of superheat of the discharge gas decreases from SH to SH'. The wetness calculation unit 13 calculates the wetness at the point A ′ by calculating the difference between SHs and SH ′.

  When the refrigerant is charged, the wetness of the suction portion of the compressor 100 is set between a predetermined upper limit value and a lower limit value, that is, the superheat degree SH is between the values corresponding to the upper limit value and the lower limit value. Thus, the control unit 11 controls the opening degree of the lead-out piping electric valve 631. If the wetness is too high, the compressor 100 may cause problems due to liquid compression. Conversely, if the wetness is too low, the refrigerant filling speed is low. It will take.

  As shown in FIG. 4, when refrigerant charging is started (step S1), the control unit 11 opens both the lead-out piping electric valve 631 and the introduction piping electromagnetic valve 621 (step S2). The opening degree of the outlet piping electric valve 631 at this time is stored in the storage unit 12 in advance.

  Subsequently, the wetness calculation unit 13 calculates the wetness of the refrigerant sucked into the compressor 100 (step S3). When the wetness is larger than the upper limit value (YES in step S4), the control unit 11 opens the opening of the outlet piping electric valve 631 in order to reduce the refrigerant filling amount into the liquid refrigerant piping 25 of the usage unit 103. (Step S5).

  When the wetness is less than or equal to the upper limit (NO in step S4), the control unit 11 determines whether or not the wetness is smaller than the lower limit (step S6). If the wetness is smaller than the lower limit value (YES in step S6), the opening degree of the outlet piping electric valve 631 is increased to increase the refrigerant charging amount (step S7). When the wetness is between the upper limit value and the lower limit value (NO in step S6), the charging rate of the refrigerant is appropriate, and therefore the control unit 11 maintains the opening degree of the outlet piping electric valve 631. (Step S8).

  When the charging of the refrigerant is completed (step S9), the control unit 11 closes both the lead-out piping electric valve 631 and the introduction piping electromagnetic valve 621 (step S10). In addition, as a completion determination method of refrigerant | coolant filling, the technique currently disclosed by patent document 1, for example can be used.

  As described above, in the first embodiment, the refrigerant in the refrigerant regulator 61 is led to the liquid pipe (for example, the liquid refrigerant pipe 20 in FIG. 1) through which the high-pressure liquid refrigerant after condensation passes as in the conventional case. In contrast, the refrigerant in the refrigerant regulator 61 is led out to the pipe connecting the expansion valve 221 and the use side heat exchanger 201, that is, the liquid refrigerant pipe 25 through which the low-pressure refrigerant after expansion in the expansion valve 221 flows. Therefore, the difference between the pressure in the refrigerant regulator 61 and the pressure in the pipe from which the refrigerant is derived (pressure in the pipe 25) can be increased as compared with the conventional case. As a result, the refrigerant in the refrigerant regulator 61 can be quickly charged into the refrigerant circuit. Therefore, it is possible to shorten the time for filling work, which is rate-limiting in the trial operation, and to shorten the time for trial operation.

  In the first embodiment, the liquid refrigerant in the refrigerant regulator 61 is introduced into the liquid refrigerant pipe 25 that connects the expansion valve 221 that squeezes and expands the liquid refrigerant and the use side heat exchanger 201. Liquid refrigerant can be evaporated in the exchanger 201 to make it difficult for liquid compression to occur in the compressor 100. Therefore, it is possible to omit the control of the wetness as described in the first embodiment.

  In the first embodiment, the control unit 11 determines the opening degree of the outlet piping electric valve 631 based on the wetness calculated by the wetness calculation unit 13, so that liquid compression occurs in the compressor 100, and compression is performed. It is possible to suppress the occurrence of problems in the machine 100.

<Embodiment 2>
FIG. 5 is a schematic configuration diagram of an air conditioner 101 according to Embodiment 2 of the present invention. The second embodiment is different from the first embodiment in that the compressor 100, the refrigerant regulator 61, and the like are provided in the use unit (indoor unit) 103. In FIG. 5, the same components as those of the air conditioner 101 according to the first embodiment are denoted by the same reference numerals as those in FIG.

  In this Embodiment 2, since the compressor 100 and the refrigerant | coolant regulator 61 are provided in the utilization unit 102, there exists an advantage that the handling of the piping at the time of connecting the derivation | leading-out piping 63 to the liquid refrigerant piping 25 can be simplified.

  As mentioned above, although Embodiment 1 and 2 of this invention were demonstrated, this invention is not limited to these Embodiment, A various change, improvement, etc. are possible in the range which does not deviate from the meaning.

  For example, in an air conditioner installed in a building or the like, an indoor unit is installed on each floor, and it is necessary to send liquid refrigerant to a higher floor, so the pressure in the liquid refrigerant pipe is kept somewhat high near the indoor unit. There is a need. Accordingly, in such an air conditioner, for example, the expansion valve 221 of FIG. 1 is provided in the indoor unit, and the liquid pipe electric valve 220 is also provided in the outdoor unit. In the case of such an air conditioner, the liquid pipe electric valve 220 of the outdoor unit is used in a substantially fully opened state during the cooling operation. In Embodiment 1, such an air conditioner is assumed, but the present invention is not limited to this. For example, the present invention can be applied to an air conditioner in which an expansion valve is provided in one of an indoor unit and an outdoor unit.

  Moreover, in the said embodiment, although illustration and description are abbreviate | omitted about the accumulator, the air conditioner 101 may be provided with the accumulator.

DESCRIPTION OF SYMBOLS 11 Control part 61 Refrigerant regulator 62 Introductory piping 63 Outlet piping 631 Outlet piping electric valve 100 Compressor 101 Air conditioner 102 Heat source unit 103 Usage unit 110 Discharge side piping 200 Heat source side heat exchanger 201 Usage side heat exchanger 221 Expansion valve

Claims (5)

A heat source side heat exchanger (200);
A use side heat exchanger (201);
An expansion valve (221) provided at a position downstream of the heat source side heat exchanger (200) and upstream of the use side heat exchanger (201) to squeeze and expand the refrigerant;
A compressor (100) provided upstream of the heat source side heat exchanger (200) and downstream of the use side heat exchanger (201);
A refrigerant regulator (61) in which refrigerant is stored;
The refrigerant branched from the discharge side pipe (110) of the compressor (100) is connected to the refrigerant regulator (61), and the refrigerant discharged from the compressor (100) is introduced into the refrigerant regulator (61). Introduction piping (62);
Connected to a pipe (25) connecting the expansion valve (221) and the use side heat exchanger (201), the refrigerant stored in the refrigerant regulator (61) is led to the pipe (25). An air conditioner comprising a lead-out pipe (63). A flow rate adjusting mechanism which is provided in at least one of the introduction pipe (62) and the outlet pipe (63) and adjusts the amount of the refrigerant stored in the refrigerant regulator (61) to the pipe (25). ,
The air conditioner according to claim 1, further comprising a control unit (11) for controlling the flow rate adjusting mechanism.   The air conditioner according to claim 2, wherein the flow rate adjusting mechanism is an electric valve (631) capable of adjusting an opening degree provided in the outlet pipe (63). A wetness calculation unit (13) that calculates a wetness that is a ratio of liquid refrigerant contained in the refrigerant flowing into the suction unit of the compressor (100);
The said control part (11) is an air conditioner of Claim 3 which determines the opening degree of the said motor operated valve (631) based on the said wetness degree. A temperature detector (111) for detecting the temperature of the discharge gas of the compressor (100);
The air conditioner according to claim 4, wherein the wetness calculation unit (13) calculates the wetness based on a temperature of the discharge gas.

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