JP2010276239A - Refrigerating air-conditioning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating air-conditioning device capable of securing a heating capacity when a temperature of outside air is low without excessively raising a compressor discharge temperature. <P>SOLUTION: In the air-conditioning device, a heat source machine 100 having a compressing device 110 with one end of an injection pipe 161 connected thereto allowing a refrigerant flowing in the injection pipe 161 to flow to an intermediate part of a compressing stroke and discharging, and a heat source machine-side heat exchanger 131 for exchanging heat is connected by piping to an indoor unit 200 having an indoor unit-side heat exchanger 210 exchanging heat between air to be conditioned and the refrigerant, and an indoor unit-side control device 220 to constitute a refrigerant circuit. One end of the injection pipe 161 is connected to a position where the refrigerant discharged by the compressing device 110 is branched and flows, and the injection pipe is disposed to be in contact with a part of the heat source-side heat exchanger 131 so that the branched refrigerant exchanges heat with the refrigerant flowing in the heat source machine side heat exchanger 131 and is condensed. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a refrigeration air conditioner that performs air conditioning by air conditioning using a refrigeration cycle (heat pump cycle). The present invention relates to a refrigeration air conditioner in which a refrigerant is introduced (injected) during a compression stroke to improve performance.

  For example, in a refrigeration air conditioner using a refrigeration cycle (heat pump cycle), basically a heat source machine (heat source machine side unit, outdoor unit) having a compressor, a heat source machine side heat exchanger, etc., and a flow rate control device (expansion) And a load side unit (indoor unit) having an indoor unit side heat exchanger and the like are connected by a refrigerant pipe to constitute a refrigerant circuit for circulating the refrigerant. Then, in the indoor unit side heat exchanger, when the refrigerant evaporates and condenses, the heat, heat is released from the air in the air-conditioning target space to be heat exchanged, and the pressure, temperature, etc. related to the refrigerant in the refrigerant circuit are changed. Air conditioning is performed while changing. Here, for example, according to the set temperature of the remote controller provided to the indoor unit and the temperature around the indoor unit, in each of the plurality of indoor units, cooling and heating are automatically determined, respectively. There is also a refrigerated air conditioner that can perform heating and cooling simultaneous operation (cooling and heating mixed operation) that can perform heating.

  On the other hand, for example, in a refrigeration air conditioner installed in a cold district or the like, when the temperature of outdoor air (hereinafter referred to as “outside air”) is low (low outside air), the heating capacity (in the indoor unit due to refrigerant circulation by the compressor during heating) In order to increase the amount of heat (per hour) supplied to the side (hereinafter referred to as the capacity including the cooling capacity), the refrigerant is supplied to the middle part of the compression stroke of the compressor provided in the heat source machine via the injection pipe. There is one that can be introduced (injected) (for example, see Patent Document 1). This is to increase the capacity by increasing the density of refrigerant discharged from the compressor. At this time, the liquid refrigerant flowing on the low pressure side in the refrigerant circuit is branched to perform injection.

JP-A-6-034221 (FIG. 1)

  However, when heating in a low outside air environment, bypassing the refrigerant on the low-pressure side, which is easily affected by outside air temperature, operation mode, etc., and injecting it into the compressor, in some cases, the differential pressure from the pressure of the refrigerant during compression may be I can't get enough. For this reason, there is a possibility that the amount of refrigerant to be injected is insufficient and the temperature of the refrigerant discharged from the compressor (hereinafter referred to as compressor discharge temperature) is excessively increased.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-described problems and to obtain a refrigeration air conditioner that can ensure the capability of low outside air without excessively increasing the compressor discharge temperature.

  A refrigeration air conditioning apparatus according to the present invention includes a compression apparatus capable of connecting one end of an injection pipe, connecting a refrigerant flowing through the injection pipe into an intermediate portion of a compression stroke, and discharging the refrigerant, and a heat source unit for performing heat exchange A refrigerant circuit is configured by pipe-connecting a heat source unit having a side heat exchanger, an indoor unit side heat exchanger that performs heat exchange between air to be air-conditioned and a refrigerant and an indoor unit having an indoor unit side flow control device. In the refrigeration air conditioner, the injection pipe has another end connected to a position where the refrigerant discharged from the compressor branches and flows, and the branched refrigerant flows through the heat source side heat exchanger and Or piping so as to be in contact with a part of the heat source side heat exchanger so as to be condensed by exchanging heat with the heat exchange medium.

  According to the present invention, the other end of the injection pipe is connected to a position where the high-pressure refrigerant discharged from the compressor branches and flows in, and is also brought into contact with a part of the heat source unit side heat exchanger to exchange heat. Since the refrigerant condensed in this way flows into the middle part of the compression stroke, a sufficient amount of differential pressure can be obtained at both ends of the injection pipe (the middle part of the compression stroke and the branched portion of the discharged refrigerant). Can be introduced into the compressor. Therefore, excessive increase in compressor discharge temperature can be prevented, and capacity can be supplied efficiently, so that sufficient heating capacity can be exhibited. Further, it is possible to prevent the compressor from being damaged due to excessive rise, and to extend the life of the entire compressor and the refrigeration air conditioner.

The figure showing the structure of the frozen air conditioning apparatus in Embodiment 1 of this invention. The figure showing the flow of the refrigerant | coolant of the whole cooling in the Embodiment 1 of this invention, and a heating only operation state. The figure showing the flow of the refrigerant | coolant of the heating main operation state in Embodiment 1 of this invention. The figure showing the flow of the refrigerant | coolant of the cooling main operation state in Embodiment 1 of this invention. The figure showing the flowchart of the control at the time of all heating operation or heating main operation. The figure showing the structure of the frozen air conditioning apparatus in Embodiment 2 of this invention. The figure showing the structure of the frozen air conditioning apparatus in Embodiment 3 of this invention.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating an overall configuration of a refrigeration air conditioner according to Embodiment 1. First, the means (apparatus) etc. which comprise a frozen air conditioning apparatus are demonstrated based on FIG. This refrigeration air conditioner performs a cooling / heating operation using a refrigeration cycle (heat pump cycle) based on refrigerant circulation. In particular, the refrigeration air conditioning apparatus of the present embodiment is an apparatus that can perform simultaneous cooling and heating operations in which a plurality of indoor units are mixed with cooling and heating at the same time.

  As shown in FIG. 1, the refrigeration air conditioning apparatus of the present embodiment mainly includes a heat source unit (heat source unit side unit, outdoor unit) 100, a plurality of indoor units (load side units) 200a, 200b and 200c, and a relay unit 300. Constitute. In this Embodiment, in order to control the flow of a refrigerant | coolant, the relay machine 300 is provided between the heat-source equipment 100 and indoor unit 200a, 200b, 200c, and these apparatuses are connected by piping with various refrigerant | coolant piping. In addition, the plurality of indoor units (load side units) 200a, 200b, and 200c are connected in parallel to each other. Note that, for example, in the indoor units 200a, 200b, and 200c, when there is no need to particularly distinguish or specify, the subscripts a, b, and c are hereinafter omitted.

  Regarding the pipe connection, the heat source device 100 and the relay device 300 are connected by the second main tube 20 and the first main tube 10 having a pipe diameter larger than that of the second main tube 20. In the second main pipe 20, a high-pressure refrigerant flows from the heat source device 100 side to the relay device 300 side. Further, in the first main pipe 10, a refrigerant having a lower pressure than the refrigerant flowing in the second main pipe 20 flows from the relay device 300 side to the heat source device 100 side. Here, the level of the pressure is not determined by the relationship with the reference pressure (numerical value), but by the pressurization of the compressor 110, the control of the open / close state (opening) of each flow control device, or the like. It is assumed that the pressure is expressed based on the relative level (including the middle) in the refrigerant circuit (hereinafter the same. Basically, the pressure of the refrigerant discharged from the compressor 110 is the highest, the flow rate control device, etc. Therefore, the pressure of the refrigerant sucked into the compressor 110 is the lowest).

  On the other hand, the repeater 300 and the indoor unit 200a are connected by the second branch pipe 40a and the first branch pipe 30a. Similarly, the repeater 300 and the indoor unit 200b are connected by the second branch pipe 40b and the first branch pipe 30b, and the repeater 300 and the indoor unit 200c are connected by the second branch pipe 40c and the first branch pipe 30c. . By connecting the first main pipe 10, the second main pipe 20, the second branch pipe 40 (40a, 40b, 40c) and the first branch pipe 30 (30a, 30b, 30c), the heat source unit 100, the relay unit 300, and the indoor unit The refrigerant circulates between 200 (200a, 200b, 200c) to constitute a refrigerant circuit.

  The heat source device 100 according to the present embodiment includes a compression device 110, a four-way switching valve 120, a heat source device side heat exchange unit 130, an accumulator 140, a heat source device side check valve unit 150, an injection pipe 161, and an injection flow rate control device 162. is doing.

  The compression device 110 of the heat source device 100 applies pressure to the sucked refrigerant and discharges (sends out) it. Here, it is assumed that the compression device 110 of the present embodiment has a two-stage configuration of a low-stage compressor 110a and a high-stage compressor 110b. The low-stage compressor 110a and the high-stage compressor 110b can arbitrarily change the drive frequency based on an instruction from the control means 400 by an inverter circuit (not shown). For this reason, the compression device 110 is an inverter compressor that can change the discharge capacity (the amount of refrigerant discharged per unit time) as a whole and the capacity according to the discharge capacity. Here, the driving frequencies of the low-stage compressor 110a and the high-stage compressor 110b may be determined in advance so as to have a predetermined ratio according to the stroke volume of each compressor. This predetermined ratio is a ratio when the suction pressure of the high-stage compressor 110b becomes a predetermined value. In addition, an injection port (not shown) for allowing the high-stage compressor 110b to suck the refrigerant flowing from the injection pipe 161 in the middle of the compression stroke between the low-stage compressor 110a and the high-stage compressor 110b. Z). For this reason, for example, when the low pressure is reduced in the environment of low outside air and the density of the refrigerant sucked by the low-stage compressor 110a is reduced, the drive rotation speed of the compressor is increased by the inverter circuit, and the refrigerant Prevents a decrease in flow rate and maintains heating capacity. In addition, when the low pressure is lowered, the operation becomes a high compression ratio, and the discharge temperature is increased by allowing the refrigerant cooled by the heat source side heat exchanger 131 to flow from the injection port through the injection port. Prevent overheating.

  The four-way switching valve 120 switches the valve corresponding to the cooling / heating mode (mode) based on the instruction of the control means 400 so that the refrigerant path is switched. In the present embodiment, the cooling only operation (herein, it means that all the indoor units being operated are cooling), the cooling main operation (cooling is the main among the simultaneous cooling and heating operations), and , The route is switched depending on the heating operation (here, all the indoor units in operation are heating) and the heating main operation (heating is the main among the simultaneous cooling and heating operations). Like that.

  The heat source machine side heat exchanger 130 includes a heat source machine side heat exchanger 131 (131a, 131b), a heat source machine side first electromagnetic on-off valve 132 (132a, 132b), and a heat source machine side second electromagnetic on-off valve 133 (133a, 133b). ), A heat source side blower 134, a heat exchanger bypass pipe 135, and a heat source side third electromagnetic on-off valve 136.

  The heat source unit side heat exchanger 131 (131a, 131b) has a heat transfer tube through which the refrigerant passes and fins (not shown) for increasing the heat transfer area between the refrigerant flowing through the heat transfer tube and the outside air. The heat exchange between the refrigerant and air (outside air) is performed. In the present embodiment, heat exchange is also performed between the refrigerant flowing through the injection pipe 161 and the refrigerant flowing through the heat transfer pipe. For example, it functions as an evaporator during the heating only operation or during the heating main operation, and evaporates and evaporates the refrigerant flowing through the heat transfer tubes. On the other hand, during the cooling only operation or the cooling main operation, it functions as a condenser and condenses and liquefies the refrigerant flowing through the heat transfer tube. In some cases, for example, during the cooling main operation, the gas is not completely gasified or liquefied, but is condensed to a state of two-phase mixing of liquid and gas (gas) (gas-liquid two-phase refrigerant). May be performed. Here, in the present embodiment, the heat source unit side heat exchange unit 130 includes two heat source unit side heat exchangers 131a and 131b. Although the heat transfer area in the fins of the heat source machine side heat exchanger 131a and the heat source machine side heat exchanger 131b may be made different from each other, the performance related to heat exchange may be made different. It is assumed that the performance relating to the heat exchange between the heat exchanger 131a and the heat source device side heat exchanger 131b is the same.

  Further, the heat source machine side first electromagnetic on / off valve 132 (132a, 132b) and the heat source machine side second electromagnetic on / off valve 133 (133a, 133b) are opened and closed based on an instruction from the control means 400, and the heat source machine side heat exchanger The refrigerant inflow / outflow to / from 131 (131a, 131b) is controlled. For example, either the heat source machine side first electromagnetic on-off valve 132a (heat source machine side second electromagnetic on / off valve 133a) or the heat source machine side first electromagnetic on / off valve 132b (heat source machine side second electromagnetic on / off valve 133b) is closed. . This prevents the refrigerant from flowing into one of the heat source machine side heat exchangers 131a and 131b so that heat cannot be exchanged, and heat exchange as a whole of the heat source machine side heat exchange unit 130 (heat source machine side heat exchanger 131) is performed. The capacity (amount of heat related to heat exchange) can be reduced.

  And the heat source side air blower 134 for performing heat exchange with a refrigerant | coolant and air efficiently is provided in the vicinity of the heat source side heat exchanger 131. The heat source device side blower 134 can change the air volume based on an instruction from the control means 400, and the heat exchange capacity in the heat source device side heat exchanger 131 can also be changed by this air volume change.

  Furthermore, it has the heat source machine side 3rd electromagnetic on-off valve 136 for controlling the refrigerant | coolant passage of the heat exchanger bypass pipe 135. FIG. For example, by opening the heat source machine side third electromagnetic on-off valve 136, the refrigerant can be passed through the heat exchanger bypass pipe 135 without passing through the heat source machine side heat exchanger 131.

  The accumulator 140 stores excess refrigerant in the refrigerant circuit. Further, the heat source machine side check valve unit 150 includes a heat source machine side first check valve 151 to a heat source machine side fourth check valve 154. Each heat source apparatus side check valve regulates the flow of the refrigerant by preventing the refrigerant from flowing back, and makes the refrigerant circulation path constant according to the mode. The heat source machine side first check valve 151 is located on the pipe between the heat source machine side heat exchange unit 130 and the heat source machine side second main pipe 20, and is directed from the heat source machine side heat exchange unit 130 to the second main pipe 20. Allow refrigerant circulation to. The heat source machine side second check valve 152 is located on the pipe between the four-way switching valve 120 and the first main pipe 10 and allows the refrigerant to flow from the first main pipe 10 toward the four-way switching valve 120. The heat source machine side third check valve 153 is located on the pipe between the four-way switching valve 120 and the second main pipe 20 and allows the refrigerant to flow from the four-way switching valve 120 to the second main pipe 20. The heat source machine side fourth check valve 154 is located on the pipe between the heat source machine side heat exchange unit 130 and the first main pipe 10, and is a refrigerant from the first main pipe 10 to the heat source machine side heat exchanger 131. Allow distribution.

  In addition, one end of the injection pipe 161 is connected to the injection port, and allows the refrigerant to flow into (supply) the compressor 110 (the high-stage compressor 110b) through the injection port. Here, the other end of the injection pipe 161 of the present embodiment is connected to a pipe between the four-way switching valve 120 and the heat source machine side third check valve 153. Then, the high-pressure gas refrigerant flowing from the four-way switching valve 120 to the heat source unit side third check valve 153 is branched during the all heating operation and the heating main operation, and the condensed refrigerant flows into the compressor 110. In order to condense the gas refrigerant, a part of the injection pipe 161 is installed so as to pass through the heat source apparatus side heat exchanger 131 (131a, 131b). Then, heat exchange is performed between the refrigerant flowing through the injection pipe 161 and / or a heat exchange medium such as outside air (air) and the refrigerant flowing through the heat transfer pipe of the heat source apparatus side heat exchanger 131 (131a, 131b). .

  Here, in the heating only operation in which the refrigerant is passed through the injection pipe 161 and the heating main operation, the heat source unit side heat exchanger 131 functions as an evaporator. At this time, moisture in the air freezes due to heat exchange, and the heat source unit side heat exchanger 131 is frosted. For this reason, for example, heat is periodically applied to the heat source apparatus side heat exchanger 131 to perform frost melting (defrosting) work. At this time, when root heating is generated in the lower part of the heat source unit side heat exchanger 131 when a heating operation, a heating main operation, or the like is performed without sufficiently removing the moisture that has dropped from the upper part of the heat source unit side heat exchanger 131 There is. Therefore, a part of the injection pipe 161 passes through the lower part of the heat source apparatus side heat exchanger 131 (131a, 131b). Thereby, the heat | fever by the heat radiation of the refrigerant | coolant in the injection pipe | tube 161 is propagated to the heat source apparatus side heat exchanger 131 (131a, 131b), and the production | generation of root ice is prevented.

  The injection flow rate control device 162 adjusts the flow rate of refrigerant that passes through the injection pipe 161 (the amount of refrigerant that flows per unit time) based on an instruction from the control unit 400.

  Moreover, in this Embodiment, the heat source machine side 1st pressure detector 170 used as the pressure sensor for detecting the pressure of the refrigerant | coolant which concerns on discharge is attached on piping connected with the discharge side of the compression apparatus 110. FIG. Based on the signal from the heat source unit side first pressure detector 170, the control unit 400 detects, for example, the pressure Pd and temperature Td of the refrigerant discharged from the compressor 110 and calculates the condensation temperature Tc and the like based on the pressure Pd. Do. Further, a heat source unit side second pressure detector 171 for detecting the pressure of the refrigerant flowing from the relay unit 300 (indoor unit 200) side is attached on the pipe connecting the heat source unit 100 and the first main pipe 10. Furthermore, an outside air temperature detector 172 for detecting the outside air temperature (outside air temperature) is attached.

  Next, the repeater 300 of this Embodiment is comprised with the repeater side gas-liquid separation apparatus 310, the 1st branch part 320, the 2nd branch part 330, and the repeater side heat exchange part 340. The repeater side gas-liquid separation device 310 separates the refrigerant flowing from the second main pipe 20 into a gas refrigerant and a liquid refrigerant. A gas phase part (not shown) from which the gas refrigerant flows out is connected to the first branch part 320. On the other hand, the liquid phase part (not shown) from which the liquid refrigerant flows is connected to the second branch part 330 via the relay-side heat exchange part 340.

  The 1st branch part 320 has the three-way switching valve 321 (321a, 321b, 321c) which has three ports. For each three-way switching valve 321, the first port is connected to the gas phase part side of the repeater side gas-liquid separation device 310. Further, the second port is connected to the first main pipe 10, and the third port is connected to each first branch pipe 30. The three-way switching valve 321 allows the refrigerant to flow from the indoor unit 200 side to the first main pipe 10 side based on an instruction from the control unit 400, or allows the refrigerant to flow from the relay unit side gas-liquid separator 310 side to the indoor unit 200 side. Switch the valve to flow.

  The 2nd branch part 330 has the relay machine side 1st check valve 331 (331a, 331b, 331c) and the relay machine side 2nd check valve 332 (332a, 332b, 332c). The repeater side first check valve 331 and the repeater side second check valve 332 are in an inverse parallel relationship, and one end of each is connected to the second branch pipe 40 (40a, 40b, 40c). To do. When the refrigerant flows from the indoor unit 200 side to the relay unit side heat exchange unit 340 side, the refrigerant passes through the relay unit side first check valve 331 and the relay unit side second bypass pipe 346 of the relay unit side heat exchange unit 340. Flowing into. Further, when the refrigerant flows from the repeater side heat exchange section 340 side to the indoor unit 200 side, it passes through the repeater side second check valve 332.

  The repeater-side heat exchange unit 340 includes a repeater-side first flow rate control device 341, a repeater-side first bypass pipe 342, a repeater-side second flow rate control device 343, a repeater-side second heat exchanger 344, a repeater Side first heat exchanger 345 and repeater side second bypass pipe 346 are provided.

  The relay-unit-side heat exchanging unit 340 supercools the liquid refrigerant and supplies it to the indoor unit 200 side, for example, during the cooling only operation. In addition, a pipe connection is made between the first main pipe 10, and the refrigerant that has flowed from the indoor unit 200 side and the refrigerant used for supercooling are caused to flow through the first main pipe 10. The repeater-side first flow rate control device 341 is provided between the repeater-side first heat exchanger 345 and the repeater-side second heat exchanger 344, and controls the opening degree based on an instruction from the control means 400. The refrigerant flow rate and the refrigerant pressure flowing from the repeater side gas-liquid separator 310 are adjusted. On the other hand, the relay-device-side second flow rate control device 343 controls the opening degree based on an instruction from the control unit 400 and adjusts the refrigerant flow rate of the refrigerant passing through the relay-device-side first bypass pipe 342. Here, the opening degree of the repeater side second flow rate control device 343 of the present embodiment is such that the temperature difference between the repeater side first temperature detector 352 and the repeater side second temperature detector 353 becomes a predetermined value. As described above, it is assumed that the control unit 400 determines. The refrigerant that has passed through the relay-side second flow rate control device 343 and the relay-side first bypass pipe 342 supercools the refrigerant in, for example, the relay-side second heat exchanger 344 and the relay-side first heat exchanger 345. The first main pipe 10 flows.

  The relay-side second heat exchanger 344 is a refrigerant in a downstream portion of the relay-side second flow control device 343 that flows through the relay-side first bypass pipe 342 (refrigerant that has passed through the relay-side second flow control device 343). And heat exchange with the refrigerant flowing from the relay-side first flow control device 341. Further, the relay-side first heat exchanger 345 includes the refrigerant that has passed through the relay-side first bypass pipe 342 and the relay-side second heat exchanger 344 and the relay-side gas-liquid separator 310 to the relay-side first heat exchanger 345. Heat exchange is performed with the refrigerant flowing through the one flow rate controller 341.

  Furthermore, the relay-unit-side second bypass pipe 346 flows the refrigerant from the indoor unit 200 that has passed through the relay-device-side first check valve 331. The refrigerant that has passed through the relay-side second bypass pipe 346 is, for example, in the cooling-main operation or heating-main operation, for example, after passing through the relay-side second heat exchanger 344 and partially or entirely performing cooling. It flows into the machine 200. Further, for example, when the all-heating operation is performed, the whole passes through the relay-unit-side second flow rate control device 343 and the relay-device-side first bypass pipe 342 and flows to the first main pipe 10.

  Further, in the relay 300, the relay-side first flow control device 341 and the relay-side gas-liquid separation device 310 are connected to detect the refrigerant pressure before and after passing through the relay-side first flow control device 341. The relay side first pressure detector 350 is attached to the pipe side. In addition, a relay-side second pressure detector 351 is attached to the pipe side connecting the second branch part 330. Based on the difference in pressure detected by the relay-side first pressure detector 350 and the relay-device-side second pressure detector 351 during the all-heating operation, the heating-main operation, or the cooling-main operation, the control means 400 The opening degree of the second flow control device 343 is determined and an instruction is given. A repeater side first temperature detector 352 is attached to a pipe connecting the first main pipe 10 and the repeater side first heat exchanger 345. Further, the relay-side second temperature detector 353 is attached to a pipe connecting the relay-device-side second flow rate control device 343 and the relay-device-side second heat exchanger 344. During the cooling only operation, for example, the control unit 400 opens the opening of the repeater side second flow rate control device 343 based on signals from the repeater side first temperature detector 352 and the repeater side second temperature detector 353. To decide.

  Next, the configuration of the indoor unit 200 (200a, 200b, 200c) will be described. The indoor unit 200 includes an indoor unit side heat exchanger 210 (210a, 210b, 210c), an indoor unit side flow control device 220 (220a, 220b, 220c) connected in series near the indoor unit side heat exchanger 210, and an indoor unit The machine side control means 230 (230a, 230b, 230c) is provided. Similarly to the heat source unit side heat exchanger 131 described above, the indoor unit side heat exchanger 210 serves as an evaporator during cooling and serves as a condenser during heating, and between the air and the refrigerant in the air-conditioning target space. Perform heat exchange. Moreover, the indoor unit side air blower 211 (211a, 211b, 211c) for performing the heat exchange with a refrigerant | coolant and air efficiently is provided in the vicinity of each indoor unit side heat exchanger 210.

  The indoor unit side flow control device 220 functions as a pressure reducing valve and an expansion valve, and adjusts the pressure of the refrigerant passing through the indoor unit side heat exchanger 210. Here, the indoor unit side flow control device 220 of the present embodiment is assumed to be composed of, for example, an electronic expansion valve that can change the opening degree. And about the opening degree of the indoor unit side flow control apparatus 220, based on the superheat degree of the refrigerant | coolant exit side (here it becomes the 1st branch pipe 30 side) of the indoor unit side heat exchanger 210 at the time of cooling, for example, each indoor The indoor unit side control means 230 of the unit 200 determines. Moreover, it determines based on the supercooling degree of the refrigerant | coolant exit side (it becomes the 2nd branch pipe 40 side here) at the time of heating. The indoor unit side control unit 230 controls the operation of each unit of the indoor unit 200. In addition, signals including various data are communicated with the control unit 400 by wire or wireless to perform processing.

  The indoor unit side first temperature detector 240 (240a, 240b, 240c) and the indoor unit side second temperature detection are connected to the refrigerant inlet and outlet pipes in the indoor unit side heat exchanger 210 of each indoor unit 200. A container 241 (241a, 241b, 241c) is attached. Based on the difference between the temperature detected by the indoor unit side first temperature detector 240 and the temperature detected by the indoor unit side second temperature detector 241, the indoor unit side control means 230 determines the degree of superheat or the degree of supercooling, respectively. The opening degree of each indoor unit side flow control device 220 is determined by calculation.

  The control means 400 performs, for example, determination processing based on signals transmitted from various detectors (sensors) provided inside and outside the refrigeration air conditioner, and each device (means) of the refrigeration air conditioner. And based on the determination, it has a function which operates each apparatus and carries out overall control of the operation | movement of the whole refrigeration air conditioning apparatus. Specifically, the drive frequency control of the compressor 110, the opening control of the flow control device such as the heat source device side flow control device 135, the open / close control of the on / off valve such as the heat source device side first electromagnetic on / off valve 132, the four-way switching valve 120, switching control of the three-way switching valve 321 and the like. The storage unit 410 temporarily or long-term stores various data, programs, and the like necessary for the control unit 400 to perform processing. Here, in the present embodiment, the control unit 400 and the storage unit 410 are provided independently of the heat source unit 100, but are often provided in the heat source unit 100, for example. In addition, the control unit 400 and the storage unit 410 are provided in the vicinity of the apparatus. For example, the control unit 400 and the storage unit 410 may be remotely controlled by performing signal communication via a public telecommunications network or the like.

  As described above, the refrigeration air conditioning apparatus of the present embodiment configured as described above can be operated in any of the four modes (modes) of the cooling only operation, the heating only operation, the cooling main operation, and the heating main operation. It can be carried out. Here, the heat source device side heat exchanger 131 of the heat source device 100 functions as a condenser during the cooling only operation and the cooling main operation, and functions as an evaporator during the heating only operation and the heating main operation. Next, basic operation of each device and refrigerant flow in the operation of each embodiment will be described.

  FIG. 2 is a diagram showing the refrigerant flow in the cooling only or heating only operation state according to the first embodiment. First, the operation of each device and the flow of refrigerant in the cooling only operation will be described with reference to FIG. The refrigerant flow in the cooling only operation is indicated by solid line arrows in FIG. Here, a case where all the indoor units 200 are performing cooling without stopping will be described. Further, the control means 400 is in a state in which the heat source machine side first electromagnetic on / off valves 132a and 132b and the heat source machine side second electromagnetic on / off valves 133a and 133b are opened, and in a state in which the heat source machine side third electromagnetic on / off valve 136 is closed. It is assumed that both the heat source apparatus side heat exchangers 131a and 131b perform heat exchange (the same applies in the description of the flow of each mode).

  In the heat source device 100, the compression device 110 compresses the sucked refrigerant and discharges the high-pressure gas refrigerant. The refrigerant discharged from the compressor 110 flows to the heat source machine side heat exchanger 131 through the four-way switching valve 120. The high-pressure gas refrigerant is condensed by heat exchange with the outside air while passing through the heat source machine side heat exchanger 131, becomes a high pressure liquid refrigerant, and flows through the heat source machine side first check valve 151 (relationship of refrigerant pressure). The heat source machine side third check valve 153 and the heat source machine side fourth check valve 154 side do not flow). Then, the high-pressure liquid refrigerant flows into the repeater 300 through the second main pipe 20.

  The relay-side gas-liquid separator 310 separates the refrigerant that has flowed into the relay 300 into a gas refrigerant and a liquid refrigerant. Here, the refrigerant flowing into the repeater 300 during the cooling only operation is a liquid refrigerant, and the control means 400 switches and controls the three-way switching valve 321 of the first branch portion 320. At this time, the first port of the three-way switching valve 321 (321a, 321b, 321c) is closed, and the second port and the third port are opened. For this reason, the gas refrigerant does not flow from the repeater side gas-liquid separator 310 to the indoor unit 200 (20a, 200b, 200c) side. On the other hand, the liquid refrigerant passes through the relay-side second heat exchanger 345, the relay-side first flow control device 341, and the relay-side second heat exchanger 344, and a part thereof flows into the second branch section 330. To do. The refrigerant that has flowed into the second branch section 330 is divided into the indoor units 200a, 200b, and 200c via the relay-device-side second check valves 332a, 332b, and 332c and the second branch pipes 40a, 40b, and 40c.

  In the indoor units 200a, 200b, and 200c, the indoor unit side flow control devices 220a, 220b, and 220c adjust the opening degree of the liquid refrigerant that has flowed from the second branch pipes 40a, 40b, and 40c, respectively. Adjust the flow rate of the flowing refrigerant. Here, as described above, the opening adjustment of each indoor unit side flow control device 220 is performed based on the degree of superheat on the refrigerant outlet side of each indoor unit side heat exchanger 210. Refrigerant that has become low-pressure liquid refrigerant or gas-liquid two-phase refrigerant by adjusting the opening degree of each indoor unit side flow rate control device 220a, 220b, 220c flows to the indoor unit side heat exchangers 210a, 210b, 210c, respectively. The low-pressure liquid refrigerant or gas-liquid two-phase refrigerant evaporates by heat exchange with the indoor air that is the air-conditioning target space while passing through the indoor unit side heat exchangers 210a, 210b, and 210c. And it becomes a low-pressure gas refrigerant and flows into the 1st branch pipes 30a, 30b, and 30c, respectively. At this time, the room air is cooled by heat exchange to cool the room. Although the gas refrigerant is used here, for example, when the air conditioning load in each indoor unit 200 (the amount of heat required by the indoor unit; hereinafter referred to as load) is small, or in a transient state such as immediately after the start, the indoor unit In the side heat exchangers 210a, 210b, and 210c, the gas-liquid two-phase refrigerant may flow without being completely vaporized. The low-pressure gas refrigerant or gas-liquid two-phase refrigerant (low-pressure refrigerant) flowing from the first branch pipes 30a, 30b, 30c passes through the three-way switching valves 321a, 321b, 321c and flows to the first main pipe 10.

  The refrigerant that has passed through the first main pipe 10 and has flowed to the heat source device 100 circulates by returning to the compression device 110 again via the heat source device side second check valve 152, the four-way switching valve 120, and the accumulator 140. This is the basic refrigerant circulation path during the cooling only operation. At this time, the injection flow control device 162 is fully closed so that the refrigerant does not flow.

  Here, the flow of the refrigerant in the repeater side heat exchange unit 340 will be described. As described above, the liquid refrigerant separated by the repeater side gas-liquid separation device 310 passes through the repeater side second heat exchanger 345, the repeater side first flow rate control device 341, and the repeater side second heat exchanger 344. Then, a part flows into the second branch part 330. On the other hand, the refrigerant that has not flowed to the second branch portion 330 side passes through the relay-device-side second flow rate control device 343. Then, the refrigerant passes through the relay-side first bypass pipe 342 and supercools the refrigerant flowing from the relay-side gas-liquid separator 310 in the relay-side second heat exchanger 344 and the relay-side first heat exchanger 345. , Flows into the first main pipe 10. By subcooling the refrigerant and flowing it to the second branch part 330 side, the enthalpy on the refrigerant inlet side (here, the second branch pipe 40 side) is reduced, and in the indoor unit side heat exchangers 210a, 210b, 210c, The amount of heat exchange with air can be increased. Here, if the opening degree of the relay-side second flow rate control device 343 is large and the amount of refrigerant (refrigerant used for supercooling) flowing through the relay-side first bypass pipe 342 increases, the amount of refrigerant that is not evaporated increases too much. For this reason, the degree of superheat of the refrigerant at the outlet of the relay unit side first flow control device 341 so that the temperature difference between the relay unit side first temperature detector 352 and the relay unit side second temperature detector 353 becomes a predetermined value. Is controlled by the second flow rate controller 343 on the repeater side.

  Here, the evaporating temperature of the refrigerant in the indoor unit side heat exchanger 210 (210a, 210b, 210c) of the indoor unit 200 (200a, 200b, 200c) and the condensing temperature of the refrigerant in the heat source unit side heat exchanger 131 are determined in advance. Try to reach the target temperature. Therefore, the control means 400 controls the discharge capacity of the compression device 110 and the air volume of the heat source unit side fan 134, and supplies the capacity corresponding to the loads of the indoor units 200a, 200b, and 200c.

  Next, the operation of each device and the flow of refrigerant in the heating only operation will be described. Here, the case where all the indoor units 200 are heating without stopping will be described. The flow of the refrigerant in the all heating operation is indicated by a dotted arrow in FIG. In the heat source device 100, the compression device 110 compresses the sucked refrigerant and discharges the high-pressure gas refrigerant. The refrigerant discharged from the compressor 110 flows through the four-way switching valve 120 and the heat source machine side third check valve 153 (the heat source machine side second check valve 152 and the heat source machine side first check valve due to the refrigerant pressure). 151 does not flow to the 151 side) and flows into the repeater 300 through the second main pipe 20.

  The refrigerant flowing into the repeater 300 is separated into a gas refrigerant and a liquid refrigerant by the repeater side gas-liquid separation device 310 and flows to the first branch section 320. Here, in the 1st branch part 320, the 2nd port of the three-way switching valve 321 (321a, 321b, 321c) is closed, and the 1st port and the 3rd port are opened. For this reason, in the 1st branch part 320, it diverts to all the indoor units 200a, 200b, 200c via the 1st branch pipes 30a, 30b, 30c from the three-way switching valve 321 (321a, 321b, 321c).

  In the indoor units 200a, 200b, and 200c, the indoor unit side flow control devices 220a, 220b, and 220c each adjust the opening degree. Thereby, the pressure of the refrigerant flowing in the indoor unit side heat exchangers 210a, 210b, and 210c is adjusted for the refrigerant that has flowed from the first branch pipes 30a, 30b, and 30c, respectively. The high-pressure gas refrigerant is condensed by heat exchange while passing through the indoor unit side heat exchangers 210a, 210b, 210c, and passes through the indoor unit side flow control devices 220a, 220b, 220c. At this time, the indoor air is heated by heat exchange to heat the air-conditioning target space (indoor). Here, the opening adjustment of each indoor unit side flow control device 220 is performed based on the degree of supercooling on the refrigerant outlet side of each indoor unit side heat exchanger 210. The refrigerant that has passed through the indoor unit side flow control devices 220a, 220b, and 220c becomes a low-pressure liquid refrigerant or a gas-liquid two-phase refrigerant, and the second branch pipes 40a, 40b, and 40c and the relay unit side first check valves 331a, 331b, It flows through the repeater side second bypass pipe 346 via 331c. Then, it passes through the repeater side second flow rate control device 343 and the repeater side first bypass pipe 342 and flows to the first main pipe 10. At this time, the low pressure gas-liquid two-phase refrigerant flows into the first main pipe 10 by adjusting the opening degree of the relay-side second flow control device 343.

  The refrigerant that has flowed into the heat source apparatus 100 from the first main pipe 10 passes through the heat source apparatus side fourth check valve 154 of the heat source apparatus 100 and flows into the heat source apparatus side heat exchanger 131. While passing through the heat source machine side heat exchanger 131, it evaporates by heat exchange with air and becomes a gas refrigerant. And it returns to the compression apparatus 110 again through the four-way switching valve 120 and the accumulator 140. Circulating by discharging as described above. This is the refrigerant circulation path during the all-heating operation.

  Here, the condensation temperature of the refrigerant in the indoor unit side heat exchanger 210 (210a, 210b, 210c) of the indoor unit 200 (200a, 200b, 200c) and the evaporation temperature of the refrigerant in the heat source unit side heat exchanger 131 are determined in advance. Try to reach the target temperature. Therefore, the control means 400 controls the discharge capacity of the compression device 110 and the air volume of the heat source unit side fan 134, and supplies capacity corresponding to the loads of the indoor units 200a, 200b, and 200c.

  Here, if the control means 400 judges that it will inject based on external temperature, it will control the injection flow control apparatus 162, and will change an opening degree. Thereby, the refrigerant discharged from the compressor 110 and condensed in the heat source apparatus side heat exchanger 131 (131a, 131b) flows into the suction side of the high stage compressor 110b from the injection port. At this time, the capability to be supplied by the compressor 110 is ensured by increasing the driving frequency.

  In the above-described cooling only operation and heating operation, all the indoor units 200a, 200b, and 200c are described as operating. However, for example, some indoor units may be stopped. Further, for example, when some of the indoor units 200 are stopped and the load of the entire refrigeration air conditioner is small, either the low-stage compressor 110a or the high-stage compressor 110b is stopped. You may make it change the capability to supply. In some cases, the heat source machine side first electromagnetic on-off valve 132 (132a, 132b), the heat source machine side second electromagnetic on / off valve 133 (133a, 133b), etc., for example, the heat source machine side heat exchanger 131 (131a, The refrigerant inflow in 131b) may be controlled to change the heat exchange capacity.

  FIG. 3 is a diagram illustrating the refrigerant flow in the heating-main operation state. Here, the case where the indoor units 200a and 200b perform heating and the indoor unit 200c performs cooling will be described. The flow of the refrigerant in the heating main operation is shown by solid line arrows in FIG. The operation of each device of the heat source device 100 and the flow of the refrigerant are the same as in the heating only operation described with reference to FIG.

  Further, the flow of the refrigerant in the heating of the indoor units 200a and 200b is the same as the flow during the heating operation described with reference to FIG. For this reason, in the three-way switching valves 321a and 321b, the second port is closed, and the first port and the third port are opened. On the other hand, the indoor unit 20c performs cooling, and the refrigerant flow differs from the indoor units 200a and 200b that perform heating. In the indoor units 200a and 200b, the refrigerant condensed by heat exchange while passing through the indoor unit side heat exchangers 210a and 210b is the indoor unit side flow rate control devices 220a and 220b, the relay unit side first check valve 331a. 331b flows to the repeater side second bypass pipe 346. Here, the control unit 400 shuts off the refrigerant flow with the relay-side gas-liquid separation device 310 by closing the relay-side first flow rate control device 341. Therefore, the condensed refrigerant passes through the relay-device-side second check valve 332c and the second branch pipe 400c, flows into the indoor unit 200c, and becomes a refrigerant used for cooling. At this time, the relay-unit-side second flow rate control device 343 is adjusted, and the control unit 400 controls the relay-device-side first heat exchanger 345 to adjust the opening degree, and supplies the refrigerant necessary for the indoor unit 200c. Meanwhile, the remaining refrigerant flows through the first main pipe 10 via the relay-side first bypass pipe 342. Here, in the three-way switching valve 321c, the first port is closed, and the second port and the third port are opened.

  Similarly to the heating only operation, when the control unit 400 determines that the injection is to be performed, the injection flow control device 162 is controlled to change the opening, and the intake port of the high-stage compressor 110b is changed from the injection port. Let the refrigerant flow into.

  In the heating-main operation, the refrigerant that has flowed out of the indoor units that are heating (here, the indoor units 20a and 20b) flows through the indoor unit that performs cooling (here, the indoor unit 20c). Therefore, when the indoor unit 200 that performs cooling stops, the amount of the gas-liquid two-phase refrigerant that flows through the relay-side first bypass pipe 342 increases. On the contrary, when the load in the indoor unit 200 that performs cooling increases, the amount of the gas-liquid two-phase refrigerant flowing through the repeater-side first bypass pipe 342 decreases. Therefore, the load of the indoor unit side heat exchanger 210 (evaporator) in the indoor unit 200 that performs cooling changes without changing the amount of refrigerant necessary for the indoor unit 200 that performs heating.

  Also in such heating-main operation, the control unit 400 controls the discharge capacity of the compression device 110 and the air volume of the heat source unit side fan 134, and supplies the capacity corresponding to each load of the indoor units 200a, 200b, and 200c. . In some cases, the heat source machine side first electromagnetic on-off valve 132 (132a, 132b), the heat source machine side second electromagnetic on / off valve 133 (133a, 133b), etc., for example, the heat source machine side heat exchanger 131 (131a, The heat transfer area and the like are changed by controlling the refrigerant inflow in 131b), and the heat exchange capacity is also changed.

  FIG. 4 is a diagram illustrating the refrigerant flow in the cooling main operation state. Here, the case where the indoor units 200a and 200b perform cooling and the indoor unit 200c performs heating will be described. The flow of the refrigerant in the cooling main operation is indicated by solid line arrows in FIG. The operation performed by each device of the heat source apparatus 100 and the flow of the refrigerant are the same as those in the cooling only operation described with reference to FIG. However, here, it is assumed that the refrigerant flowing into the relay 300 through the second main pipe 20 becomes a gas-liquid two-phase refrigerant by controlling the condensation of the refrigerant in the heat source apparatus side heat exchanger 131.

  Further, the flow of the refrigerant from the indoor units 200a and 200b in which cooling is performed, through the first main pipe 10 and into the heat source unit 100, is the same as the flow in the all cooling operation described with reference to FIG. It is the same. On the other hand, the refrigerant flow related to the indoor unit 200c that performs heating is different from the indoor units 200a and 200b that perform cooling. First, the gas-liquid two-phase refrigerant that has flowed into the repeater 300 is separated into a gas refrigerant and a liquid refrigerant by the repeater-side gas-liquid separator 310. For the three-way switching valves 321a and 321b of the first branching section 320, the control means 400 closes the first port, opens the second port and the third port, and opens the gas refrigerant on the indoor units 200a and 200b side. Is prevented from flowing. On the other hand, with respect to the three-way switching valve 321c, the second port is closed, the first port and the third port are opened, and the gas refrigerant flows to the indoor unit 200c side through the first branch pipe 30c. .

  In the indoor unit 200c, the flow rate of the refrigerant flowing in the indoor unit side heat exchanger 210c is adjusted for the refrigerant flowing from the first branch pipe 30c by adjusting the opening degree of the indoor unit side flow rate control device 220c. The high-pressure gas refrigerant is condensed by heat exchange while passing through the indoor unit side heat exchanger 210c, and passes through the indoor unit side flow control device 220c. At this time, the room air is heated by heat exchange to heat the room. The refrigerant that has passed through the indoor unit side flow control device 220c becomes liquid refrigerant with a slight decrease in pressure, and flows through the relay unit side second bypass pipe 346 via the second branch pipe 40c and the relay unit side first check valve 331c. . Then, it merges with the liquid refrigerant flowing from the relay-side gas-liquid separator 310, flows to the indoor units 200a and 200b, and is used as a refrigerant for cooling.

  Thus, in the cooling main operation, the heat source unit side heat exchanger 131 of the heat source unit 100 functions as a condenser. The refrigerant that has passed through the indoor unit 200 that performs heating (here, the indoor unit 200c) is used as a refrigerant for the indoor unit 200 that performs cooling (here, the indoor units 200a and 200b). Here, when the load on the indoor units 200a and 200b is small and the refrigerant flowing through the indoor units 200a and 200b is suppressed, the control unit 400 increases the opening degree of the relay-unit-side second flow rate control device 343. . Thereby, even if it does not supply the refrigerant | coolant more than necessary to the indoor units 200a and 200b which are cooling, it can flow to the 1st main pipe 10 via the relay machine side 1st bypass piping 342.

  Also in such a cooling main operation, the control unit 400 controls the discharge capacity of the compression device 110 and the air volume of the heat source unit side fan 134, and supplies the capacity corresponding to each load of the indoor units 200a, 200b, and 200c. . In some cases, the heat source machine side first electromagnetic on-off valve 132 (132a, 132b), the heat source machine side second electromagnetic on / off valve 133 (133a, 133b), etc., for example, the heat source machine side heat exchanger 131 (131a, The heat transfer area and the like are changed by controlling the refrigerant inflow in 131b), and the heat exchange capacity is also changed.

  Here, when the outside air temperature becomes low, the compression ratio becomes too high, and the compressor discharge temperature by the compressor 110 becomes high (too high). In the all heating operation and the heating main operation, the pressure in the heat source apparatus side heat exchanger 131 serving as an evaporator (pressure on the suction side of the compressor 110) decreases. Therefore, the refrigerant (circulating refrigerant) sucked into the compression device 110 decreases (refrigerant density decreases), the compression ratio becomes too high, and the temperature of the refrigerant discharged from the compression device 110 (discharge temperature) increases. Therefore, the control means 400 controls the injection flow control device 162 to change the opening degree. Thus, the refrigerant density is increased by supplementing the refrigerant from the injection port, and the temperature of the refrigerant sucked by the high stage compressor 110b is lowered so that the compressor discharge temperature does not rise excessively.

  In the present embodiment, one end of the injection pipe 161 is connected to a pipe between the four-way switching valve 120 and the heat source device side third check valve 153, and the four-way switching valve 120 to the heat source device side third check valve 153. The high-pressure gas refrigerant flowing through the pipe is branched. Then, a part of the injection pipe 161 passes through the heat source unit side heat exchanger 131 (131a, 131b), heat exchange is performed with the refrigerant flowing through the heat transfer pipe, and the condensed refrigerant is compressed into the compressor 110 ( It flows into the high stage side compressor 110b). A stable high-pressure refrigerant discharged from the compression device 110 is decompressed and adjusted by the injection flow control device 162, and a sufficient differential pressure is provided, so that a stable amount of refrigerant can flow into the compression device 110 from the injection port. .

  At this time, the refrigerant passing through the injection pipe 161 is a high-temperature refrigerant (temperature is higher than that of the outside air). For this reason, in the heat source machine side heat exchanger 131 (131a, 131b), heat exchange can be performed efficiently. And when performing injection, the heat | fever of the refrigerant | coolant which passes the injection pipe | tube 161 is propagated at least to the lower part of the heat source apparatus side heat exchanger 131 (131a, 131b), and the production | generation of root ice is prevented.

  FIG. 5 is a diagram illustrating a flowchart for performing control related to injection. First, based on the signal transmitted from the outside air temperature detector 172, the control unit 400 determines whether or not the outside air temperature is lower than a predetermined outside air temperature (low outside air determination) (STEP 1).

  If it is determined that the outside air temperature is not lower than the predetermined outside air temperature (the outside air temperature is equal to or higher than the predetermined outside air temperature), the control unit 400 closes the injection flow rate control device 162 (leaves it when it is closed). Thus, the refrigerant is prevented from flowing into the injection pipe 161, and control by normal operation is performed (STEP 8).

  On the other hand, if it is determined that the outside air temperature is lower than the predetermined outside air temperature, it is determined whether or not it is in a state where the all heating operation or the heating main operation is performed (STEP 2). If it is determined that the heating only operation or the heating main operation is not performed (the cooling only operation or the cooling main operation is performed), the control unit 400 closes the injection flow rate control device 162 (when it is closed, it remains as it is. (STEP 8).

  When it is determined that the all heating operation or the heating main operation is being performed, control is performed to adjust the opening degree of the injection flow rate control device 162 so that the refrigerant flows through the injection pipe 161. Then, the refrigerant is caused to flow into the compression device 110 via the injection port.

Therefore, the control means 400 detects (determines) the pressure Pd and the temperature Td of the refrigerant discharged from the compressor 110 based on the detection of the heat source unit side first pressure detector 170 (STEP 3). Further, the condensation temperature Tc is calculated based on the pressure Pd, and the discharge superheat degree TdSH that is the difference between the temperature Td and the condensation temperature Tc is calculated (STEP 4). Further, the target opening difference ΔLEV of the injection flow control device 162 is calculated based on the following equation (1) (STEP 5). Here, TdSH _m represents the discharge superheat degree set as a target and stored in the storage unit 410. K is a constant.
ΔLEV = k (TdSH−TdSH _m ) (1)

Based on the calculated ΔLEV, the next opening degree target LEV _m of the injection flow rate control device 162 is calculated based on the following equation (2) (STEP 6). Here, LEV represents the current opening target.
LEV _m = LEV + ΔLEV (2)

  The above processing is repeated every predetermined time (STEP 7), and the control unit 400 controls the flow rate of the refrigerant flowing through the injection pipe 161 by controlling the opening degree of the injection flow rate control device 162.

  As described above, according to the refrigeration air conditioning apparatus of the first embodiment, one end of the injection pipe 161 is connected to the pipe between the four-way switching valve 120 and the heat source unit side third check valve 153, and heating is performed. During operation and heating-main operation, the high-pressure gas refrigerant flowing from the four-way switching valve 120 to the heat source unit side third check valve 153 is branched and condensed by passing through the heat source unit side heat exchanger 131 (131a, 131b). Since the refrigerant whose pressure is adjusted by the injection flow control device 162 is caused to flow into the compressor 110, the difference from the suction side pressure of the high stage compressor 110b (the discharge side pressure of the low stage compressor 110a). The pressure can be stabilized. As a result, a stable amount of refrigerant can be caused to flow into the compressor 110 when injection is performed in the all-heating operation or the heating-main operation in low outside air. In addition, by performing injection, it is possible to prevent overheating in the compressor 110, to reduce the discharge superheat degree, and to exhibit sufficient heating capacity by increasing the speed of the compressor. At this time, since a part of the injection pipe 161 passes through the lower part of the heat source machine side heat exchanger 131 (131a, 131b), the heat source machine side heat exchanger 131 (131a) is radiated by the heat radiation of the refrigerant in the injection pipe 161. 131b) can be prevented from generating root ice.

Embodiment 2. FIG.
FIG. 6 is a diagram illustrating an overall configuration of a refrigeration air conditioning apparatus according to Embodiment 2 of the present invention. In FIG. 6, means and the like denoted by the same reference numerals as those in FIG. 1 perform the same functions and operations as those described in the first embodiment. The compressor 110 described above has a two-stage configuration of a low-stage compressor 110a and a high-stage compressor 110b. However, the compressor 111 according to the present embodiment is configured by a single compressor. And in the compressor which comprises the compression apparatus 111, a part of compression chamber is opened, and it is made to provide an injection port directly in the intermediate pressure part in the middle of a compression process.

  As described above, according to the refrigeration air conditioning apparatus of the second embodiment, the apparatus configuration is configured by the compression apparatus 111 configured by one compressor having a part of the compression chamber opened and provided with the injection port. The cost can be reduced as compared with the case of using two compressors. Moreover, the space concerning the installation of the compressor in the heat source apparatus 100 can be made smaller than mounting two units.

Embodiment 3 FIG.
FIG. 7 is a diagram showing the overall configuration of a refrigeration air conditioning apparatus according to Embodiment 3 of the present invention. In FIG. 7, means and the like having the same reference numerals as those in FIG. 1 perform the same functions and operations as those described in the first embodiment. In FIG. 7, when the heat source device side fourth electromagnetic on-off valve 137 performs the defrosting operation in the heat source device 100, the refrigerant discharged from the compression device 110 does not pass through the first main pipe 10 (second main pipe 20). It is what you want to do.

  In the present embodiment, a defrosting operation performed to remove frost attached to the heat source unit side heat exchanger 131 in the heat source unit 100 will be described. First, when performing the defrosting operation, the control means 400 closes the heat source machine side fourth electromagnetic on-off valve 137 and the refrigerant discharged from the compression device 110 enters the heat source machine side third check valve 153 and the first main pipe 10. Do not flow. Further, the injection flow rate control device 162 is fully opened.

For example, the refrigerant discharged from the compressor 110 due to the pressurization of the high-stage compressor 110b passes through the four-way switching valve 120 and passes through the injection pipe 161 (injection flow rate controller 162). At this time, the frost attached to the heat source unit side heat exchanger 131 and the refrigerant exchange heat (the frost side absorbs heat), so that the frost melts and flows down from the heat source unit side heat exchanger 131.
The refrigerant that has passed through the injection pipe 161 flows from the injection port and is pressurized by the high-stage compressor 110b. Thereby, a refrigerant circulates and constitutes a defrost circuit. Further, in the defrosting operation, the heat source side blower 134 is temporarily stopped, the four-way switching valve 120 is switched to the position for performing the cooling operation, and the hot gas (high temperature refrigerant) is passed through the heat source side heat exchanger 131. To defrost. Thereafter, the remaining frost at the bottom of the heat source side heat exchanger 131 may be melted in the refrigerant flow of FIG.

  As described above, according to the refrigeration air conditioner of Embodiment 3, the defrosting circuit is configured using the injection pipe 161 (injection flow rate control device 162), and the defrosting operation is performed. The defrosting of the heat source machine side heat exchanger 131 can be performed well.

Embodiment 4 FIG.
In the above-described embodiment, the refrigeration air conditioner that has the relay 300 and can perform the cooling and heating simultaneous operation has been described. However, the present invention is not limited to such a device. For example, the present invention can be applied to a refrigerated air conditioner that switches between cooling and heating. Further, the present invention can be applied to a refrigeration air conditioner in which an indoor unit (load side unit) is dedicated to heating (heating).

  10 1st main pipe, 20 2nd main pipe, 30a, 30b, 30c 1st branch pipe, 40a, 40b, 40c 2nd branch pipe, 100 heat source machine, 110,111 compressor, 110a low stage side compressor, 110b high stage Side compressor, 120 four-way switching valve, 130 heat source machine side heat exchange section, 131a, 131b heat source machine side heat exchanger, 132a, 132b heat source machine side first electromagnetic on-off valve, 133a, 133b heat source machine side second electromagnetic on-off valve , 134 Heat source machine side blower, 135 Heat exchanger bypass pipe, 136 Heat source machine side third electromagnetic on-off valve, 137 Heat source machine side fourth electromagnetic on-off valve, 140 Accumulator, 150 Heat source machine side check valve section, 151 Heat source machine side First check valve, 152 Heat source machine side second check valve, 153 Heat source machine side third check valve, 154 Heat source machine side fourth check valve, 161 Injection pipe, 162 , Heat source unit side first pressure detector, 171 heat source unit side second pressure detector, 172 outside air temperature detector, 200a, 200b, 200c indoor unit, 210a, 210b, 210c indoor unit side heat exchanger , 211a, 211b, 211c Indoor unit side blower, 220a, 220b, 220c Indoor unit side flow control device, 230a, 230b, 230c Indoor unit side control means, 240a, 240b, 240c Indoor unit side first temperature detector, 241a, 241b, 241c Indoor unit side second temperature detector, 300 relay unit, 310 relay unit side gas-liquid separation device, 320 first branch part, 321a, 321b, 321c three-way switching valve, 330 second branch part, 331a, 331b, 331c Relay machine side first check valve, 332a, 332b, 332c Relay machine side second check valve 340 Repeater side heat exchange section, 341 Repeater side first flow control device, 342 Repeater side first bypass piping, 343 Repeater side second flow control device, 344 Repeater side second heat exchanger, 345 Repeater Side first heat exchanger, 346 repeater side second bypass piping, 350 repeater side first pressure detector, 351 repeater side second pressure detector, 352 repeater side first temperature detector, 353 repeater side Second temperature detector, 400 control means, 410 storage means.

Claims (7)

A heat source machine having a compressor connected to one end of the injection pipe and capable of flowing the refrigerant flowing through the injection pipe into an intermediate portion of the compression stroke and discharging it; and a heat source side heat exchanger for performing heat exchange A refrigerating air conditioner that configures a refrigerant circuit by pipe-connecting an indoor unit side heat exchanger that performs heat exchange between air to be air-conditioned and an indoor unit and an indoor unit side flow rate control device,
The injection pipe has another end pipe-connected to a position where the refrigerant discharged from the compressor branches and flows, and the branched refrigerant flows through the heat source unit side heat exchanger and / or a heat exchange medium. A refrigeration air conditioning apparatus, wherein piping is provided so as to contact with a part of the heat source unit side heat exchanger so as to condense after heat exchange.   A relay device that is between the heat source unit and the plurality of indoor units and forms a flow path for supplying a gaseous refrigerant to the indoor unit that performs heating and supplying a liquid refrigerant to the indoor unit that performs cooling The refrigeration air conditioning apparatus according to claim 1, further comprising a pipe connection.   The refrigeration air conditioner according to claim 1 or 2, wherein a plurality of compressors are connected in series to constitute the compressor, and one end of the injection pipe is connected to a connecting portion of the compressor.   The refrigeration air conditioner according to any one of claims 1 to 3, wherein the injection pipe and the heat source apparatus side heat exchanger are brought into contact with each other at a lowermost portion of the heat source apparatus side heat exchanger. An injection flow controller for adjusting the amount of refrigerant passing through the injection pipe;
Control means for instructing the opening degree of the injection flow control device,
When the control means determines that the temperature of the air that exchanges heat with the refrigerant passing through the heat source unit side heat exchanger is equal to or lower than a predetermined temperature, the control means opens the injection flow control device to compress the refrigerant. The refrigeration air conditioning apparatus according to any one of claims 1 to 4, wherein control is performed to flow into the apparatus.   6. The refrigeration air conditioner according to claim 5, wherein the control means controls the opening degree of the injection flow control device based on the degree of superheat of the refrigerant discharged from the compression device.   The said control means performs control which fully opens the said flow control apparatus for injection, when performing the defrost operation for removing the frost attached to the said heat-source equipment side heat exchanger. The refrigeration air conditioning apparatus described.

Images