WO2011039851A1

WO2011039851A1 - Heat-source-side unit and refrigeration air conditioner

Info

Publication number: WO2011039851A1
Application number: PCT/JP2009/067007
Authority: WO
Inventors: 智基稲垣; 博幸岡野; 修森本; 晋司岡
Original assignee: 三菱電機株式会社
Priority date: 2009-09-30
Filing date: 2009-09-30
Publication date: 2011-04-07
Also published as: EP2484995A4; EP2484995A1; JP5583134B2; EP2484995B1; JPWO2011039851A1

Abstract

Disclosed are a heat-source-side unit and a refrigeration air conditioner, both of which enable the effective utilization of tanks or the like and also enable highly efficient recovery or the like. Specifically disclosed is a heat-source-side unit (100) which comprises a compressor (101) and a heat-source-side heat exchanger (104), and also comprises a coolant circuit which is formed by the pipe connection between a load-side throttle device (202) and a load-side heat exchanger (201). In the heat-source-side unit (100), the coolant circuit is provided with an oil tank (110) for feeding a refrigerating machine oil that is lost by the washing of the coolant circuit into the compressor (101) to refill the refrigerating machine oil.

Description

Heat source unit and refrigeration air conditioner

The present invention relates to a heat source side unit and a refrigeration air conditioner. In particular, the present invention relates to an apparatus that can clean an existing refrigerant pipe and collect foreign matter when installing an air conditioner.

Conventionally, when installing a refrigeration air conditioner, which is a so-called separate type refrigeration cycle apparatus, in a building such as a building, installation using existing refrigerant piping (hereinafter referred to as existing piping) may be performed. For example, the heat source side unit to be removed and the load side unit are replaced (replaced) with a new heat source side unit (outdoor unit) and a load side unit (indoor unit), and connected to the existing piping to install the apparatus. In such an installation, it is not necessary to newly replace the refrigerant pipe, so that labor, cost, and time required for the refrigerant pipe replacement work can be reduced. Moreover, since only the heat source side unit and the load side unit are replaced, a large construction is not required for a building or the like where the refrigeration air conditioner is installed, and the reliability of the refrigeration air conditioner is improved.

When using the existing pipe as described above, in the refrigeration air conditioner, the old refrigerating machine oil (mineral oil) remaining in the existing pipe after replacing the heat source side unit and the load side unit is usually deteriorated. Or the like (hereinafter, referred to as Patent Document 1, for example).

Japanese Patent Laying-Open No. 2004-333121 (FIG. 2)

In the refrigeration air conditioning apparatus as described above, for example, a new refrigerant is circulated in a refrigerant circuit that circulates the refrigerant, and foreign substances remaining in the existing piping are washed away by the refrigerant to be recovered ( Hereinafter, the operation for cleaning and collecting foreign substances is referred to as the recovery operation). For this reason, a collecting device (collecting tank) that captures and collects the washed-out foreign matters by a filter, gravity separation or the like is required. In addition, an oil tank for replenishing new refrigeration oil (hereinafter referred to as refrigeration oil) that has become insufficient in the recovery operation is also required.

The recovery unit and oil tank as described above occupy a large volume in the heat source side unit. For example, after the recovery operation, the recovery unit and the oil tank should remain in the heat source side unit until the next heat source side unit is replaced. There are many. Here, the oil tank is provided independently of the refrigerant circuit, and conventionally, piping connection for refilling the compressor oil to the compressor is performed separately from the oil separator (oil separator) in the refrigerant circuit. It was.

Also, the recovery unit is provided on a separate pipe connected in parallel with the refrigerant circuit. Here, for example, when the outside air temperature is low, the stagnation of the refrigerant occurs in the collector, and the refrigerant may accumulate more than necessary in the collector. In such a state, if it is determined that the refrigerant is insufficient in the refrigerant circuit and the refrigerant is replenished, the amount of refrigerant charged may increase carelessly. As a result, the refrigerant is excessively charged to increase the cost, or the excessive refrigerant increases, the refrigerant overflows from the accumulator, the liquid returns to the compressor excessively, and the compressor is damaged. There was a possibility.

The present invention has been made in order to solve the above-described problems. The heat source side can be used for efficient use of a tank, perform efficient recovery, etc., and can make the amount of refrigerant appropriate. An object is to provide a unit and a refrigeration air conditioner.

A heat source side unit according to the present invention is a heat source side unit that includes a compressor and a heat source side heat exchanger, and forms a refrigerant circuit by pipe connection between the expansion device and the load side heat exchanger. The refrigerant circuit is further provided with an oil tank for sending the refrigerating machine oil deficient due to the above to the compressor for replenishment. Further, it is assumed that the oil tank and the recovery device are integrally formed with a pressure-resistant partition.

According to the present invention, the oil tank is provided in the refrigerant circuit so as to allow the refrigerant to pass therethrough, so that the refrigerant circuit can be simplified, the workability can be improved, and the manufacturing cost can be reduced. Further, the pulsation of the refrigerant discharged from the compressor can be reduced in the oil tank. Furthermore, by integrally forming the oil tank and the recovery device, it is possible to prevent a temperature drop of the recovery device and to prevent the refrigerant from stagnation in the recovery device. For this reason, it is possible to accurately determine the amount of refrigerant reduced by the recovery operation and replenish an appropriate amount of refrigerant. Therefore, the risk that excess refrigerant returns to the compressor can be reduced, and a highly reliable system can be obtained.

It is a figure showing the structure of the frozen air conditioning apparatus which concerns on Embodiment 1. FIG. It is a figure showing the procedure which concerns on replacement including a collection | recovery driving | operation. It is a flowchart showing the process which concerns on the filling of the refrigerant | coolant to the refrigerant circuit in a collection | recovery driving | operation.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a refrigeration air conditioning apparatus according to Embodiment 1 of the present invention. In the present embodiment, a refrigeration air conditioner that is a refrigeration cycle (heat pump cycle) device will be described. 1 includes a heat source side unit (outdoor unit) 100 and a load side unit (indoor unit) 200, which are connected by a refrigerant pipe to form a refrigerant circuit (hereinafter referred to as a refrigerant circuit). The refrigerant is circulated. Among the refrigerant pipes, a pipe through which a gaseous refrigerant (gas refrigerant) flows is referred to as a gas pipe 300, and a pipe through which a liquid refrigerant (liquid refrigerant, which may be a gas-liquid two-phase refrigerant) flows is referred to as a liquid pipe 400. In the present embodiment, it is assumed that the heat source side unit (outdoor unit) 100 and the load side unit (indoor unit) 200 are new units after replacement. Further, it is assumed that the gas pipe 300 and the liquid pipe 400 are existing pipes. Here, the level of pressure is not determined by the relationship with the reference pressure (numerical value). For example, suppose that it represents based on relative height in a refrigerant circuit by pressurization of compressor 101, control of the opening-and-closing state (opening degree) of each throttle device (flow control device), etc. The same applies to temperature.

As for the refrigerant circulating in the refrigerant circuit, non-azeotropic refrigerant mixture (R407C etc.), pseudo azeotropic refrigerant mixture (R410A, R404A etc.), single refrigerant (R22, R134a etc.), natural refrigerant (carbon dioxide, propane etc.) ) Etc. can be used. Here, the types of refrigerant before and after the replacement may be the same or different.

The heat source side unit 100 of this embodiment includes a compressor 101, an oil separator 102, a four-way valve 103, a heat source side heat exchanger 104, a heat source side fan 105, an accumulator 106, a heat source side expansion device (expansion valve) 107, a first one. 2 heat source side expansion device (expansion valve) 133, on-off valve 134, refrigerant supply on-off valve 108, refrigerant charging port on-off valve 109, oil tank 110, inter-refrigerant heat exchanger 113, and

check valves

114 and 115 as refrigerant. On the circuit. Further, the recovery device 111 and the capillary tube 112 are connected by a separate system from the refrigerant circuit. And it has the heat source side control apparatus 120 in order to control each apparatus (means) on a refrigerant circuit. The oil tank 110 and the recovery device 111 are integrally formed via a copper end plate or the like.

The compressor 101 includes an inverter circuit, a compressor motor, and the like. The inverter circuit controls the rotation speed of the compressor motor (operating frequency of the compressor 101), compresses the refrigerant used in the refrigeration cycle, and circulates the refrigerant pipe. The oil separator 102 separates the refrigerating machine oil that becomes the lubricating oil mixed with the refrigerant and discharged from the compressor 101 from the refrigerant. Then, the separated refrigerating machine oil is caused to flow to the oil tank 110 through the oil pipe 116 and returned to the compressor 101 via the oil tank 110 to unify the oil return path.

The four-way valve 103 switches the refrigerant flow between the cooling operation and the heating operation based on an instruction from the heat source side control device 120. The heat source side heat exchanger 104 performs heat exchange between the refrigerant and air (outdoor air). For example, it functions as an evaporator during heating operation, and performs heat exchange between a low-pressure refrigerant and air, evaporating and evaporating the refrigerant. Further, during the cooling operation, it functions as a condenser and performs heat exchange between the refrigerant compressed in the compressor 101 flowing in from the four-way valve 103 side and air, thereby condensing and liquefying the refrigerant. The heat source side heat exchanger 104 is provided with a heat source side fan 105 in order to efficiently exchange heat between the refrigerant and the air. The heat source side fan 105 may also have an inverter circuit so that the operation frequency of the fan motor is arbitrarily changed to finely change the rotation speed of the fan.

The accumulator 106 is means for storing, for example, liquid surplus refrigerant. In the present embodiment, it also serves to separate foreign substances and the like. The heat source side expansion device 107 adjusts, for example, the flow rate and pressure of the refrigerant flowing from the pipe through which the liquid refrigerant mainly flows to the pipe through which the gas refrigerant mainly flows. Further, the second heat source side expansion device 133 mainly adjusts the pressure according to the saturation value based on the detection of the downstream pressure sensor (not shown) according to the pressure resistance of the liquid pipe 400 during cooling. Further, during heating, the amount of liquid back to the accumulator 106 is adjusted by the discharge superheat degree of the compressor 101.

The oil tank 110 is filled with refrigerating machine oil. For example, when the refrigerating machine oil mixed and discharged from the compressor 101 during the collecting operation does not stay in the collecting unit 111 and returns, the oil tank 110 becomes insufficient. The compressor 101 is replenished. Here, in the present embodiment, the refrigerant inflow pipe port 110A and the refrigerant outflow pipe port 110B are provided, and the oil separator 102 (compressor 101) and the four-way valve 103 (the four-way valve 103 are not provided) on the refrigerant circuit. The oil tank 110 is provided between the heat source side heat exchanger 104 and the heat source side heat exchanger 104). Further, in the present embodiment, one housing is partitioned by a mirror plate or the like to form two spaces, one space is an oil tank 110, and the other space is a collector 111. Although not shown in particular, an on-off valve is provided so that the refrigeration oil does not leak from the oil tank 110 at the time of shipment. Details of the oil tank 110 and the like will be described later.

The collecting device 111 has a filter, sufficient space for lowering (sedimenting) foreign matter by gravity, and is carried along with the refrigerant to collect the foreign matter and the like accumulated at the bottom of the accumulator 106. The flowing refrigerant is returned to the accumulator 106. For this reason, a recovery circuit different from the refrigerant circuit is formed by the recovery pipe 117 with the accumulator 106. Further, the recovery pipe 117 is provided with a recovery on-off valve 118, which is closed except when the recovery device 111 recovers foreign matter or the like so that the foreign matter or the like does not leak.

Capillary tube (capillary tube) 112 adjusts the amount of refrigerating machine oil sent from oil tank 110 to compressor 101 in oil pipe 116 for sending oil from oil tank 110 to the suction side of compressor 101. Here, the amount of refrigerating machine oil may be adjusted using a solenoid valve, a flow rate adjusting device, or the like instead of the capillary tube 112. Further, the capillary tube 112 and the electromagnetic valve are arranged in parallel so that the refrigerating machine oil can be supplied to the compressor 101 by opening the electromagnetic valve in a state where the refrigerating machine oil is insufficient, such as immediately after cleaning. Good.

The inter-refrigerant heat exchanger 113 performs heat exchange between the refrigerant flowing in and out of the liquid pipe 400 and the refrigerant flowing in and out of the gas pipe 300. In particular, in the present embodiment, since the gas-liquid two-phase refrigerant has a higher pipe cleaning effect than the gas or liquid single-phase refrigerant, the gas-liquid two-phase refrigerant is transferred to the liquid pipe 400 by heat exchange during the recovery operation. And let it pass through the gas pipe 300. Further, during normal cooling operation, the liquid refrigerant sent to the load side unit 200 and the refrigerant from the load side unit 200 are heat-exchanged to supercool the liquid refrigerant. The

check valves

114 and 115 are provided to bypass the refrigerant flowing from the load-side unit 200 so that the refrigerant does not pass through the inter-refrigerant heat exchanger 113 during normal heating operation.

The refrigerant supply opening / closing valve 108 opens to form a refrigerant flow from the discharge side of the compressor 101 to the suction side, and serves as a supply port for charging the refrigerant from the outside (refrigerant cylinder or the like). This is a valve for allowing the refrigerant to flow from the compressor to the compressor 101 suction side. The refrigerant charging port opening / closing valve 109 is a valve for supplying the refrigerant from the refrigerant charging port and charging the refrigerant.

The heat source side control device 120 is composed of, for example, a microcomputer. It is possible to perform wired or wireless communication with the load-side control device 204. For example, based on data relating to detection by various detection means (sensors) in the refrigeration air conditioner, the operation frequency control of the compressor 101 by inverter circuit control, Then, the respective units related to the refrigeration air conditioner are controlled to control the operation of the entire refrigeration air conditioner.

The discharge temperature sensor 130 and the discharge pressure sensor 131 are temperature detection means for detecting the temperature and pressure of the refrigerant discharged from the compressor 101. In the present embodiment, the heat source side heat exchange temperature sensor 132 serves as a temperature detection unit that detects the temperature of the refrigerant related to condensation when the heat source side heat exchanger 104 functions as a condenser.

On the other hand, the load side unit 200 includes a load side heat exchanger 201, a load side expansion device (expansion valve) 202, a load side fan 203, and a load side control device 204. The load side heat exchanger 201 performs heat exchange between the refrigerant and air. For example, it functions as a condenser during heating operation, performs heat exchange between the refrigerant flowing in from the gas pipe 300 and air, condenses and liquefies the refrigerant (or gas-liquid two-phase), and moves to the liquid pipe 400 side. Spill. On the other hand, during the cooling operation, it functions as an evaporator, performs heat exchange between the refrigerant and the air whose pressure is reduced by the load-side throttle device 202, causes the refrigerant to take heat of the air, evaporates it, and vaporizes it. It flows out to the piping 300 side. In addition, the load side unit 200 is provided with a load side fan 203 for adjusting the flow of air for heat exchange. The operating speed of the load-side fan 203 is determined by, for example, user settings. The load side expansion device 202 is provided to adjust the flow rate of the refrigerant by changing the opening, and to adjust the pressure of the refrigerant in the load side heat exchanger 201.

Further, the load side control device 210 is also composed of a microcomputer or the like, and can communicate with the heat source side control device 120 by wire or wireless, for example. Based on an instruction from the heat source side control device 120 and an instruction from a resident or the like, for example, each device (means) of the load side unit 200 is controlled so that the room has a predetermined temperature. Further, a signal including data related to detection by the detection means provided in the load side unit 200 is transmitted. In the present embodiment, the load-side heat exchange temperature sensor 220 is a temperature detection unit that detects the temperature of the refrigerant related to condensation, particularly when the load-side heat exchanger 201 functions as a condenser.

In this embodiment, an oil tank 110 is provided (in series) in the refrigerant circuit. In particular, a muffler is provided between the compressor 101 and the four-way valve 103 to reduce the pulsation of refrigerant discharged from the compressor 101 due to discharge characteristics such as reciprocating motion and periodic motion due to rotation in the compressor 101. To function as. Conventionally, refrigerant pulsation may be reduced by expanding a part of the refrigerant piping of the refrigerant circuit or providing a special device. In this embodiment, the interior has a space after the recovery operation. A different oil tank 110 is used.

Here, for example, if the volume inside the oil tank 110 is too small, the frequency band that can be reduced becomes narrow, and the function as a muffler cannot be performed. Therefore, in the present embodiment, the oil tank 110 is configured so that the internal volume becomes 2 liters or more in order to widen a frequency band that can be reduced or the like.

Also, the oil tank 110 is already filled with refrigeration oil at the start of the recovery operation, for example, before shipment. In this embodiment, since the gas refrigerant passes through the oil tank 110, for example, when the distance between the refrigerant outlet and the oil level of the refrigerating machine oil is short, the oil level undulates due to the flow of the flowing refrigerant, etc. A large amount of refrigeration oil may flow out from the refrigerant outlet. In addition, if the refrigerant inlet is close to the oil level of the refrigerating machine oil, for example, the gas refrigerant may cause the oil level to ripple.

Therefore, in the present embodiment, the internal volume of the oil tank 110 is made sufficiently larger than the required refrigerating machine oil filling amount. The oil tank 110 has a cylindrical shape, and allows the refrigerant to flow along the tangential direction of the cylindrical shape. Thereby, the effect which prevents that a liquid level swells by inflow of a refrigerant | coolant is acquired. Even in the initial state (at the start of the recovery operation), a sufficient distance (space) is provided between the oil level of the refrigerating machine oil in the oil tank 110 and the refrigerant inlet pipe port 110A and the refrigerant outlet pipe port 110B. For this reason, the refrigerant inflow pipe and the refrigerant outflow pipe are provided at positions on the upper surface of the oil tank 110. Here, the distance is desirably at least three times the diameter of the refrigerant inlet pipe port 110A and the refrigerant outlet pipe port 110B, for example. Furthermore, the diameter of the cylindrical oil tank 110 is desirably eight times or more the diameter of the refrigerant inlet pipe port 110A and the refrigerant outlet pipe port 110B. As a result, even if the oil surface is somewhat waved and oil droplets are generated, the oil drops due to the influence of gravity (self-weight), so that the refrigerating machine oil can be prevented from flowing out.

In the refrigeration air conditioner of the present embodiment, by providing the oil tank 110 between the compressor 101 and the four-way valve 103, heating and cooling can be performed in the load side unit 200 even during the recovery operation. .

Further, in the present embodiment, two spaces are formed in one housing, and one is the oil tank 110 and the other is the recovery device 111 so that the heat in the oil tank 110 is transmitted to the recovery device 111. To. The collector 111 is basically provided in parallel with the refrigerant pipe through which the refrigerant after passing through the gas pipe 300 and the liquid pipe 400 passes. Therefore, if the temperature of the refrigerant is low and the outside air temperature is low, the refrigerant may stagnate. Therefore, as described above, when the high-temperature refrigerant from the compressor 101 passes through the oil tank 110, the heat is transferred to the recovery unit 111 in the same casing, and the recovery unit 111 is warmed to stagnate the refrigerant. Can be prevented. As a result, the refrigerant can always be operated in an appropriate state. In addition, by accurately determining the amount of refrigerant, it is not necessary to supply excessive refrigerant. For example, the amount of excess refrigerant that accumulates in the accumulator 106 is reduced, and the risk of liquid return to the compressor 101 is reduced. High system can be obtained.

Here, the relationship between the oil separator 102 and the oil tank 110 will be described. Both the oil separator 102 and the oil tank 110 feed refrigeration oil to the compressor 101. Since the oil tank 110 is used for the recovery operation, the refrigeration oil is sent to the compressor 101 through independent pipes.

In this embodiment, an oil pipe 116 is connected between the oil separator 102 and the oil tank 110, and the refrigeration oil separated from the refrigerant by the separator 102 is sent to the oil tank 110. For this reason, refrigeration oil is supplied to the compressor 101 from the oil tank 110 via the capillary tube 112 not only during the recovery operation but also during the normal operation. For this reason, piping can be reduced and simplification can be achieved. Further, the refrigeration oil can be temporarily stored in the oil tank 110. Note that the oil separator 102 may be eliminated and the refrigerating machine oil may be separated and stored only in the oil tank 110. In this case, although there is a concern that the separation efficiency of the refrigerating machine oil will be reduced, the amount of refrigerating machine oil that has been deteriorated in advance and circulated through the refrigerant circuit (taken out) is measured and filled with a large amount of refrigerating machine oil The reliability can be secured.

FIG. 2 is a diagram showing a procedure related to replacement including recovery operation. First, update of the refrigeration air conditioner is started (STEP 1). The existing heat source unit 100 and the like are removed (STEP 2). Install a new unit (STEP 3). The gas pipe 300 and the liquid pipe 400 are connected to the new unit (STEP 4). After evacuating the liquid pipe 400, the gas pipe 300, and the load side unit 200, the refrigerant for the load side unit 200 is charged (STEP 5). Then, the on-off valve (not shown) between the heat source side unit 100, the liquid pipe 400, and the gas pipe 300 is opened to perform a recovery operation (STEP 6). After the recovery on-off valve 118 is closed and a test operation of the air conditioning operation is performed (STEP 7), the update is completed (STEP 8).

Next, the recovery operation of STEP 6 will be described. First, operation control in the case of performing recovery operation while cooling in the load side unit 200 will be described based on the flow of the refrigerant. The operation control related to the recovery operation is performed by the heat source side control device 120.

The high-temperature and high-pressure gas refrigerant discharged from the compressor 101 reaches the heat source side heat exchanger 104 via the oil separator 102, the oil tank 110, and the four-way valve 103, and is condensed and liquefied. The condensed and liquefied liquid refrigerant is cooled in the inter-refrigerant heat exchanger 113 and becomes a supercooled refrigerant and flows into the liquid pipe 400 through the check valve 114.

The gas-liquid two-phase refrigerant that has flowed into the liquid pipe 400 flows to the load-side unit 200 while stripping off foreign matters and the like in the liquid pipe 400 with the flow of the refrigerant. The refrigerant containing foreign matter or the like that has flowed to the load side unit 200 is throttled to a low pressure by the load side expansion device 202, takes heat from the surroundings by the load side heat exchanger 201, and a part of the liquid refrigerant evaporates to be air-conditioned space. , And becomes a gas-liquid two-phase refrigerant, flows out from the load-side unit 200, and flows into the gas pipe 300.

The gas-liquid two-phase refrigerant that has flowed to the gas pipe 300 flows to the heat source side unit 100 while stripping off foreign matters and the like in the gas pipe 300. As described above, the gas-liquid two-phase refrigerant including the foreign matter and the like that has returned to the heat source side unit 100 undergoes heat exchange with the condensed and liquefied liquid refrigerant, and is completely gasified. Then, the refrigerant is sucked into the compressor 101 via the four-way valve 103 and the accumulator 106, and circulated by being compressed and discharged as described above.

Here, the foreign matter or the like is separated from the refrigerant by gravity or the like in the accumulator 106 and settles at the bottom of the accumulator 106. When the recovery on-off valve 118 is opened, a part of the dynamic pressure in the refrigerant changes to a static pressure inside the accumulator 106, while the pressure in the recovery device 111 becomes lower than the pressure of the accumulator 106. A flow of foreign matter or the like from 106 to the collector 111 occurs. As a result, the foreign matter or the like separated in the accumulator 106 passes through the recovery pipe 117 via the recovery on-off valve 118 and flows to the recovery device 111 and is recovered.

At this time, for the refrigerating machine oil, the oil separator 102 sends the separated refrigerating machine oil to the oil tank 110 through the oil pipe 116. Further, a shortage of refrigeration oil is sent from the oil tank 110 to the compressor 101 via the capillary tube 112.

After performing the above operation for a predetermined time, the heat source side control device 120 controls each device so that the refrigerant flowing through the liquid pipe 400 becomes the liquid refrigerant. Moreover, it controls so that the refrigerant | coolant which flows through the gas piping 300 turns into a gas refrigerant. In this way, the refrigerant amount adjustment control is performed so as to be the same as the refrigerant distribution state in the normal operation related to cooling.

FIG. 3 is a flowchart showing a process relating to charging of the refrigerant into the refrigerant circuit during the recovery operation. It is assumed that the control relating to this process is also performed by the heat source side control device 120. The recovery operation corresponding to STEP 6 described above is started (STEP 11). In particular, in the initial state of the recovery operation, the refrigerant circuit is filled with only the refrigerant previously charged in the heat source side unit 100 and the refrigerant for the load side unit 200 that has been charged after evacuation. It becomes. Therefore, it is determined whether the temperature value Td of the refrigerant discharged from the compressor 101 detected by the discharge temperature sensor 130 is larger than the preset upper limit value Tdmax of discharge temperature (Td> Tdmax) (STEP 12).

If it is determined that Td> Tdmax, the refrigerant supply on-off valve 108 and the refrigerant charging port on-off valve 109 are opened to fill the refrigerant (STEP 14). On the other hand, if it is determined that Td> Tdmax is not satisfied, the refrigerant supply on-off valve 108 and the refrigerant charging port on-off valve 109 are closed (STEP 13). Then, the above-described processing is performed until it is determined that a predetermined time relating to the collection of foreign matters has elapsed (STEP 15). Here, regarding the determination in STEP 12, in the present embodiment, since the refrigerant stagnation does not occur in the recovery device 111, it is possible to prevent a decrease in the amount of refrigerant circulating in the refrigerant circuit and to prevent unnecessary refrigerant charging.

When the predetermined time has elapsed, the heat source side control device 120 starts the refrigerant amount adjustment control described above (STEP 16). The process waits until it is determined again that the predetermined time has passed (STEP 17).

Then, the saturation temperature Tsat (Pd) is calculated based on the refrigerant discharge pressure Pd detected by the discharge pressure sensor 131 (STEP 18). Then, a difference SC from the refrigerant temperature Tcout flowing out of the heat source side heat exchanger 104 detected by the heat source side heat exchange temperature sensor 132 is calculated (STEP 19). Further, when the difference SC is compared with the target value SCm and it is determined that SC ≧ SCm (STEP 20), the refrigerant supply on-off valve 108 and the refrigerant charging port on-off valve 109 are closed (STEP 21), and the recovery operation is terminated. (STEP 23). If it is determined that SC ≧ SCm is not satisfied (SC <SCm), the refrigerant supply on-off valve 108 and the refrigerant charging port on-off valve 109 are opened (STEP 22), the refrigerant is charged for a predetermined time (STEP 16), and again after STEP 17 Process. In addition, when the refrigerant filling completion condition is not satisfied for a predetermined time or longer, it may be displayed on a display means (not shown) included in the heat source side unit 100, a remote controller (not shown), or the like. Further, when the refrigerant charging is completed, the completion may be notified from the heat source side unit 100, the remote controller, or the like. Further, the completion of the refrigerant charging may be stored in a storage unit (not shown) of the heat source side control device 120 so that it can be confirmed later. At this time, it may be stored together with the operating state.

Next, operation control when the recovery operation is performed while heating in the load side unit 200 will be described based on the flow of the refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 101 becomes a gas-liquid two-phase refrigerant in the oil separator 102, the oil tank 110, the four-way valve 103, and the inter-refrigerant heat exchanger 113, and the refrigerant flowing into the gas pipe 300 is The foreign matter in the gas pipe 300 flows to the load side unit 200 while being peeled off by the flow of the refrigerant.

The refrigerant containing foreign matter and the like that has flowed into the load-side unit 200 dissipates heat around the load-side heat exchanger 201, condenses, heats the air-conditioning target space, and is squeezed to an intermediate pressure by the load-side throttle device 202. It becomes a gas-liquid two-phase refrigerant containing etc., flows out from load side unit 200, and flows into liquid piping 400. The gas-liquid two-phase refrigerant that has flowed to the liquid pipe 400 flows to the heat source side unit 100 while stripping off foreign matters and the like in the liquid pipe 400.

A part of the gas-liquid two-phase refrigerant including foreign matter and the like that has returned to the heat source side unit 100 flows into the heat source side heat exchanger 104 via the check valve 115, and the rest flows between the refrigerant heat exchanger 113 and the on-off valve 134. And flows to the refrigerant inflow side (upstream side) of the accumulator 106. The refrigerant evaporated and vaporized in the heat source side heat exchanger 104 is sucked into the compressor 101 via the four-way valve 103 and the accumulator 106, and circulated by being compressed and discharged as described above. The gas-liquid two-phase refrigerant that has flowed to the inter-refrigerant heat exchanger 113 evaporates by exchanging heat with the high-temperature and high-pressure gas refrigerant discharged from the compressor 101 and flows to the refrigerant inflow side of the accumulator 106 via the on-off valve 134. . After the above operation is performed for a predetermined time, the refrigerant amount adjustment control is performed so as to be the same as the refrigerant distribution state in the case of performing a normal operation related to heating.

At this time, as described above, the foreign matter or the like separated in the accumulator 106 passes through the recovery pipe 117 via the recovery on-off valve 118 and flows to the recovery device 111 and is recovered. As for the refrigeration oil, a shortage of refrigeration oil is sent from the oil tank 110 to the compressor 101.

Also, the processing related to the charging of the refrigerant in the case where heating is performed in the load side unit 200 is basically the same as the processing described based on FIG. However, regarding the temperature Tcout, the temperature of the refrigerant flowing out from the load-side heat exchanger 201 detected by the load-side heat exchange temperature sensor 220 is defined as a temperature Tcout. When a plurality of load-side units 200 are installed, the average temperature detected by the load-side heat exchange temperature sensor 220 is defined as a temperature Tcout.

As described above, when a new unit is renewed and installed using existing piping, the amount of refrigerant can be correctly determined and the refrigerant can be charged even when the shape of the existing piping is embedded in a wall or ceiling. Therefore, the construction time can be shortened. Further, since the refrigerant amount can be determined regardless of whether it is cooling or heating, the reliability with respect to the refrigerant amount can be improved regardless of the existing installation.

As described above, according to the refrigeration air conditioning apparatus of Embodiment 1, the oil tank 110 that stores the refrigeration oil for replenishing the compressor 101 is provided in series in the refrigerant circuit during the recovery operation, and compressed. Since the gas refrigerant discharged from the machine 101 is allowed to pass therethrough, the refrigerant can be disturbed in the space inside the oil tank 110, so that the muffler can reduce the pulsation of the refrigerant caused by the discharge characteristics of the compressor 101. Thereby, since the pulsation of the refrigerant is not transmitted to other devices of the heat source side unit 100, the load side unit 200, etc., vibration, sound, etc. generated in the device (pipe, equipment) due to the pulsation of the refrigerant can be reduced. It is possible to obtain a device with improved reliability by preventing breakage and extending the service life. By making the oil tank 110 a muffler, the oil tank 110 having a large space can be effectively used, and by eliminating the muffler, the heat source side unit 100 can be reduced in volume, reduced in size, and reduced in material cost. Can do. Moreover, since piping can be simplified, productivity can be improved.

Further, since the oil tank 110 is provided at a position through which the gas refrigerant discharged from the compressor 101 passes regardless of the operation state, heating is performed even when the load side unit 200 is cooling during the recovery operation. However, the pulsation of the refrigerant can be reduced. Furthermore, by setting the size of the oil tank to a predetermined size (for example, 2 liters) or more, the pulsation of the refrigerant can be reduced corresponding to a wide range of frequencies and wavelengths related to the pulsation. Then, the refrigerant inflow pipe and the refrigerant outflow pipe are provided at a position on the upper surface of the oil tank 110, and when the oil level of the refrigerating machine oil stored in the oil tank 110 is at the highest position (usually before the start of the recovery operation). In this stage), a sufficient distance (space) is provided between the refrigerant inflow pipe port 110A and the refrigerant outflow pipe port 110B and the oil level. Outflow can be prevented. Therefore, a shortage of refrigeration oil in the compressor 101 can be prevented, and a highly reliable refrigeration air conditioner can be obtained. Further, since the volume inside the oil tank 110 is increased in order to secure the space, the effect of reducing the pulsation of the refrigerant can be further enhanced.

Further, the heat of the gas refrigerant passing through the oil tank 110 is transmitted to the recovery device 111 during the recovery operation or normal air-conditioning operation, and the recovery device 111 is heated to prevent the refrigerant from stagnation in the recovery device 111. can do. For this reason, the shortage of the amount of refrigerant in the refrigerant circuit can be determined with high accuracy, and inadvertent charging of a large amount of refrigerant can be prevented. For this reason, cost reduction and environmental conservation can be achieved.

Further, since the refrigeration oil separated by the oil separator 102 is returned to the compressor 101 via the oil tank 110, the piping path related to the oil can be made into one system, and the piping can be simplified. it can. For this reason, cost reduction and productivity improvement can be achieved.

Embodiment 2. FIG.
In the above-described embodiment, the oil tank 110 and the recovery device 111 are defined as two spaces in which one casing is separated by a mirror plate. However, if the heat of the oil tank 110 can be transmitted to the recovery device 111, it is limited to this. It is not a thing. For example, the two tanks of the oil tank 110 and the recovery device 111 may be brought into contact with each other to be integrated.

Embodiment 3 FIG.
Embodiment 1 mentioned above demonstrated the frozen air conditioning apparatus which connected the heat-source side unit 100 and the load side unit 200 one each. The present invention is not limited to this, and can also be applied to a multi-type refrigeration air conditioner in which a plurality of heat source side units 100 and load side units 200 are connected. At this time, the heat source side unit 100 having a recovery function may be one unit or all units.

In the above-described embodiment, the four-way valve 103 is provided in order to allow the load-side unit 200 to perform air conditioning. However, a configuration without the four-way valve 103 may be employed. In such a case, the oil tank 110 is provided between the oil separator 102 (compressor 101) and the heat source side heat exchanger 104.

In the above-described embodiment, the load side unit 200 is also described as being replaced. However, the present invention can also be applied to the case where only the heat source side unit 100 is replaced with a new one.

Furthermore, in the above-described embodiment, the recovery operation is performed by the refrigerant circuit in which the load side unit 200 is connected by piping. For example, the recovery is performed by connecting the gas piping 300 and the liquid piping 400 by a bypass piping. After the operation, the load side unit 200 may be connected by piping.

In the above-described embodiment, the application to the refrigeration air conditioner has been described.
For example, the present invention can also be applied to other refrigeration cycle apparatuses that constitute a refrigerant circuit, such as a heat pump apparatus, a refrigeration apparatus, and a refrigeration apparatus.

100 heat source side unit, 101 compressor, 102 oil separator, 103 four-way valve, 104 heat source side heat exchanger, 105 heat source side fan, 106 accumulator, 107 heat source side throttle device, 108 refrigerant supply on / off valve, 109 refrigerant filling port On-off valve, 110 oil tank, 110A refrigerant inlet pipe port, 110B refrigerant outlet pipe port, 111 collector, 112 capillary tube, 113 inter-refrigerant heat exchanger, 114, 115 check valve, 116 oil pipe, 117 recovery pipe, 118 Recovery open / close valve, 120 Heat source side control device, 130 Discharge temperature sensor, 131 Discharge pressure sensor, 132 Heat source side heat exchange temperature sensor, 200 Load side unit, 201 Load side heat exchanger, 202 Load side throttle device, 203 load Side fan, 210 load side control device, 2 0 load-side heat exchanger temperature sensor 300 gas piping, 400 liquid pipe.

Claims

The heat source side unit having a compressor and a heat source side heat exchanger, and forming a refrigerant circuit by piping connection between the expansion device and the load side heat exchanger,
The heat source side unit, further comprising an oil tank in the refrigerant circuit for sending and replenishing the refrigerating machine oil which is insufficient due to the washing of the refrigerant circuit to the compressor.
2. The heat source side unit according to claim 1, wherein the oil tank is provided at a position through which the gas phase refrigerant sent from the compressor passes in the refrigerant circuit.
An oil separator for separating the refrigerating machine oil contained in the refrigerant,
The piping for sending the refrigerating machine oil separated by the oil separator to the compressor via the oil tank is connected between the oil separator and the oil tank. The heat source side unit described.
The heat source side unit according to any one of claims 1 to 3, wherein the volume of the oil tank is 2 liters or more.
A recovery device for capturing and recovering foreign matter related to the cleaning of the refrigerant circuit;
The heat source side unit according to any one of claims 1 to 4, wherein the recovery unit is brought into contact with the oil tank or integrated in the same casing.
The heat source unit according to any one of claims 1 to 5, wherein the oil tank has an inlet pipe and an outlet pipe for the refrigerant on an upper surface.
The heat source side unit according to claim 6, wherein the distance between the inlet and outlet pipe ports and the oil level of the refrigeration oil in the oil tank is at least three times the pipe diameter.
One or more heat source side units according to claims 1 to 7,
A refrigeration air conditioner comprising a throttle device and one or a plurality of load side units having a load side heat exchanger connected by piping.