WO2008069265A1 - Climatiseur - Google Patents

Climatiseur Download PDF

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Publication number
WO2008069265A1
WO2008069265A1 PCT/JP2007/073566 JP2007073566W WO2008069265A1 WO 2008069265 A1 WO2008069265 A1 WO 2008069265A1 JP 2007073566 W JP2007073566 W JP 2007073566W WO 2008069265 A1 WO2008069265 A1 WO 2008069265A1
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WO
WIPO (PCT)
Prior art keywords
refrigerant
unit
heating
pressure
heat source
Prior art date
Application number
PCT/JP2007/073566
Other languages
English (en)
Japanese (ja)
Inventor
Yoshio Ueno
Original Assignee
Daikin Industries, Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daikin Industries, Ltd. filed Critical Daikin Industries, Ltd.
Publication of WO2008069265A1 publication Critical patent/WO2008069265A1/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B9/00—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point
    • F25B9/002—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant
    • F25B9/008—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point characterised by the refrigerant the refrigerant being carbon dioxide
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B13/00—Compression machines, plants or systems, with reversible cycle
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2309/00—Gas cycle refrigeration machines
    • F25B2309/06—Compression machines, plants or systems characterised by the refrigerant being carbon dioxide
    • F25B2309/061—Compression machines, plants or systems characterised by the refrigerant being carbon dioxide with cycle highest pressure above the supercritical pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/023—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units
    • F25B2313/0233—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units in parallel arrangements
    • F25B2313/02334—Compression machines, plants or systems with reversible cycle not otherwise provided for using multiple indoor units in parallel arrangements during heating
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2313/00—Compression machines, plants or systems with reversible cycle not otherwise provided for
    • F25B2313/027—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means
    • F25B2313/02741—Compression machines, plants or systems with reversible cycle not otherwise provided for characterised by the reversing means using one four-way valve
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2500/00—Problems to be solved
    • F25B2500/19—Calculation of parameters
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2500/00—Problems to be solved
    • F25B2500/28—Means for preventing liquid refrigerant entering into the compressor
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B2600/00—Control issues
    • F25B2600/25—Control of valves
    • F25B2600/2513—Expansion valves

Definitions

  • the present invention relates to an air conditioner, in particular, a plurality of utilization units including a utilization side expansion mechanism and a utilization side heat exchanger are connected to a heat source unit including a compressor and a heat source side heat exchanger. It is related with the air conditioning apparatus in which the heating operation by the refrigerating cycle operation in which the high pressure side becomes the pressure exceeding the critical pressure of the refrigerant is provided.
  • a heating operation is possible having a refrigerant circuit configured by connecting a plurality of utilization units including a utilization side expansion valve and a utilization side heat exchanger to a heat source unit.
  • a refrigerant circuit configured by connecting a plurality of utilization units including a utilization side expansion valve and a utilization side heat exchanger to a heat source unit.
  • utilization side expansion valve configured by connecting a plurality of utilization units including a utilization side expansion valve and a utilization side heat exchanger to a heat source unit.
  • multi-type air conditioners There are so-called multi-type air conditioners.
  • Patent Document 1 Japanese Unexamined Patent Publication No. 2003-121015
  • the usage units in the heating stopped state are in the usage unit. Since the refrigerant flow in the refrigerant is eliminated, the refrigerant pressure at the high-pressure side of the refrigeration cycle operation is mainly the same as that of the utilization unit during heating! If the stagnation phenomenon occurs and the amount of refrigerant stagnating in the use unit when heating is stopped (hereinafter referred to as refrigerant stagnation amount) increases, the amount of refrigerant circulating in the refrigerant circuit may be insufficient.
  • the discharge temperature of the compressor for compressing the refrigerant excessively rises, and heating cannot be continued.
  • the opening degree of the use side expansion valve of the use unit during the heating stop is temporarily set.
  • the refrigerant recovery operation described above uses the discharge temperature of the compressor as a threshold value, control for increasing the opening of the use-side expansion valve relatively abruptly in consideration of protection of the compressor.
  • the upper limit control of the discharge temperature is performed, a large refrigerant flow noise is generated in the use unit that is not heating.
  • the refrigerant discharge temperature is increased because the refrigerant pressure on the high-pressure side exceeds the critical pressure of the refrigerant. Consideration for excessive rise of the refrigerant is further required, and refrigerant flow noise in the use unit during discharge temperature upper limit control is likely to occur.
  • An object of the present invention is to provide a refrigerant circuit configured by connecting a plurality of utilization unit forces including a utilization side expansion mechanism and a utilization side heat exchanger, and a heat source unit including a compressor and a heat source side heat exchanger. It has an air conditioner that can be heated by refrigeration cycle operation where the high pressure side exceeds the critical pressure of the refrigerant, and the discharge temperature of the compressor is excessively increased by the refrigerant stagnation phenomenon. This is to prevent the generation of refrigerant flow noise in the use unit when heating is stopped.
  • a plurality of utilization units including a utilization side expansion mechanism and a utilization side heat exchanger are connected to a heat source unit including a compressor and a heat source side heat exchanger.
  • a heat source unit including a compressor and a heat source side heat exchanger.
  • the refrigerant pressure in the user-side heat exchanger exceeds the critical pressure and is not in a gas-liquid two-phase state, so it exists in the user unit from the refrigerant temperature and refrigerant pressure in the user unit. It is possible to calculate the amount of refrigerant to be performed.
  • the refrigerant stagnation amount of the usage unit when heating is stopped is calculated, and the use side expansion mechanism of the usage unit when heating is stopped is controlled according to the calculated refrigerant stagnation amount. Therefore, it is possible to prevent the refrigerant discharge temperature from being excessively increased due to a shortage of the refrigerant circulating in the refrigerant circuit due to the refrigerant stagnation in the use unit that is not heating.
  • the use side expansion mechanism is controlled more finely than when the discharge temperature upper limit control is performed, which is the refrigerant recovery operation that recovers the refrigerant that has fallen into the use unit that has stopped heating with the discharge temperature of the compressor as a threshold value.
  • the discharge temperature upper limit control is performed, which is the refrigerant recovery operation that recovers the refrigerant that has fallen into the use unit that has stopped heating with the discharge temperature of the compressor as a threshold value.
  • heating is stopped here means not only when the user has intentionally instructed the unit to stop heating using a remote controller or the like, but also during the heating, This includes cases where the condition continues for a long time.
  • the air conditioner according to the second aspect of the invention is the air conditioner according to the first aspect of the invention.
  • the refrigerant temperature is the inlet side of the use side heat exchanger during heating, the use side during heating. It is detected by a temperature sensor provided on at least one of the outlet side of the heat exchanger and the use side heat exchanger.
  • thermosensors provided on at least one of the inlet side of the use side heat exchanger during heating, the outlet side of the use side heat exchanger during heating, and the use side heat exchanger Since the refrigerant temperature detected by the above is used for calculating the refrigerant stagnation amount, the calculation accuracy of the refrigerant stagnation amount can be improved.
  • the air conditioner according to the third aspect of the present invention is the same as the air conditioner according to the second aspect of the present invention!
  • the usage side expansion mechanism of the usage unit that is not warmed is controlled so that the refrigerant passes through the usage unit that is not heated.
  • This air conditioner produces a refrigerant flow in the use unit when heating is stopped.
  • the refrigerant temperature detection accuracy can be increased.
  • FIG. 1 is a schematic configuration diagram of an air conditioner according to an embodiment of the present invention.
  • FIG. 2 is a pressure-enthalpy diagram illustrating the refrigeration cycle.
  • FIG. 3 is a flowchart of discharge temperature upper limit control and refrigerant stagnation control.
  • FIG. 1 is a schematic configuration diagram of an air-conditioning apparatus 1 according to an embodiment of the present invention.
  • the air conditioner 1 is an apparatus used for indoor air conditioning by performing a vapor compression refrigeration cycle operation.
  • the air conditioner 1 is a refrigerant communication pipe that connects the heat source unit 2, a plurality of (here, two) use units 4 and 5, and the heat source unit 2 and the use units 4 and 5.
  • the first refrigerant communication pipe 6 and the second refrigerant communication pipe 7 are provided. That is, the vapor compression refrigerant circuit 10 of the air conditioner 1 of the present embodiment is configured by connecting the heat source unit 2, the utilization units 4 and 5, and the refrigerant communication pipes 6 and 7. The Yes.
  • the refrigerant circuit 10 is compressed to a pressure exceeding the critical pressure of the refrigerant, cooled, depressurized, heated and evaporated, and then again.
  • the refrigeration cycle operation of being compressed is performed.
  • the utilization units 4 and 5 are installed indoors and connected to the heat source unit 2 via the refrigerant communication pipes 6 and 7 and constitute a part of the refrigerant circuit 10.
  • the configuration of the usage units 4 and 5 will be described. Since the usage unit 4 and the usage unit 5 have the same configuration, only the configuration of the usage unit 4 will be described here, and the configuration of the usage unit 5 indicates each part of the usage unit 4. Instead of the 40's code, the 50's code is used, and the description of each part is omitted.
  • the usage unit 4 mainly has a usage-side refrigerant circuit 10a (in the usage unit 5, the usage-side refrigerant circuit 10b) that constitutes a part of the refrigerant circuit 10.
  • the use side refrigerant circuit 10a mainly includes a use side expansion mechanism 41 and a use side heat exchanger 42.
  • the use-side expansion mechanism 41 is a mechanism for decompressing the refrigerant.
  • the use-side expansion mechanism 41 adjusts the flow rate of the refrigerant flowing in the use-side refrigerant circuit 10a (the use-side refrigerant circuit 10b in the use unit 5).
  • This is an electric expansion valve connected to one end of the use side heat exchanger 42 to perform the above.
  • the use side expansion mechanism 41 has one end connected to the first refrigerant communication pipe 6 and the other end connected to the use side heat exchanger 42.
  • the use side heat exchanger 42 is a heat exchanger that functions as a refrigerant heater or cooler.
  • the utilization heat exchanger 42 has one end connected to the utilization side expansion mechanism 41 and the other end connected to the second refrigerant communication pipe 7.
  • the usage unit 4 includes a usage-side fan 43 for sucking indoor air into the unit and supplying it to the room again.
  • the usage unit 4 includes a refrigerant flowing through the usage-side heat exchanger 42 and the indoor air. It is possible to exchange heat.
  • the use side fan 43 is rotationally driven by a use side fan drive motor 43a.
  • the utilization unit 4 is provided with various sensors. Specifically, when the use-side heat exchanger 42 is functioned as a refrigerant cooler, the first use-side heat for detecting the cooler outlet refrigerant temperature Tho is provided on the outlet side of the use-side heat exchanger 42. Exchanger temperature sensor 44 When the use side heat exchanger 42 functions as a refrigerant cooler, the use side heat exchanger 42 has a second use side heat exchanger that detects the refrigerant inlet refrigerant temperature Thi at the inlet side. A temperature sensor 45 is provided. In the present embodiment, the use side heat exchanger temperature sensors 44 and 45 are thermistors. In addition, the usage unit 4 has a usage-side control unit 46 that controls the operation of each unit constituting the usage unit 4.
  • the use-side control unit 46 includes a microcomputer, a memory, and the like provided for controlling the use unit 4, and is connected to a remote controller (not shown) for individually operating the use unit 4. Control signals etc. can be exchanged between them, and control signals etc. can be exchanged with the heat source unit 2 via the transmission line 8a.
  • the heat source unit 2 is installed outside and is connected to the usage units 4 and 5 through the refrigerant communication pipes 6 and 7, and the refrigerant circuit 10 is configured between the usage units 4 and 5.
  • the heat source unit 2 mainly has a heat source side refrigerant circuit 10c constituting a part of the refrigerant circuit 10! /.
  • the heat source side refrigerant circuit 10c mainly includes a compressor 21, a switching mechanism 22, a heat source side heat exchanger 23, a heat source side expansion mechanism 24, a first closing valve 25, and a second closing valve 26. have.
  • the compressor 21 is a hermetic compressor driven by a compressor drive motor 21a. In the present embodiment, only one compressor 21 is provided. However, the present invention is not limited to this, and two or more compressors 21 may be connected in parallel depending on the number of connected units. Good.
  • the switching mechanism 22 is a mechanism for switching the direction of the flow of the refrigerant in the refrigerant circuit 10.
  • the heat source side heat exchanger 23 is used as a refrigerant cooler compressed by the compressor 21.
  • the discharge side of the compressor 21 and one end of the heat source side heat exchanger 23 are connected.
  • the heating-side heat exchangers 42 and 52 are connected by the compressor 21 during heating.
  • the switching mechanism 22 is a four-way switching valve connected to the suction side of the compressor 21, the discharge side of the compressor 21, the heat source side heat exchanger 23, and the second closing valve 26. Note that the switching mechanism 22 is not limited to a four-way switching valve.
  • the switching mechanism 22 is configured to have a function of switching the flow direction of the refrigerant as described above by combining a plurality of solenoid valves. It may be.
  • the heat source side heat exchanger 23 is a heat exchanger that functions as a refrigerant cooler or heater.
  • One end of the heat source side heat exchanger 23 is connected to the switching mechanism 22, and the other end is connected to the heat source side expansion mechanism 24! /.
  • the heat source unit 2 has a heat source side fan 27 for sucking outdoor air into the unit and discharging it outside the room again.
  • the heat source side fan 27 can exchange heat between the outdoor air and the refrigerant flowing through the heat source side heat exchanger 23.
  • the heat source side fan 27 is rotationally driven by a heat source side fan drive motor 27a.
  • the heat source of the heat source side heat exchanger 23 may be another heat medium such as water, which is not limited to outdoor air.
  • the heat source side expansion mechanism 24 is a mechanism for decompressing the refrigerant.
  • the other end of the heat source side heat exchanger 23 is used to adjust the flow rate of the refrigerant flowing in the heat source side refrigerant circuit 10c. It is an electric expansion valve connected to.
  • One end of the heat source side expansion mechanism 24 is connected to the heat source side heat exchanger 23, and the other end is connected to the first closing valve 25.
  • the first closing valve 25 is a valve to which a first refrigerant communication pipe 6 for exchanging refrigerant between the heat source unit 2 and the utilization units 4 and 5 is connected, and is connected to the heat source side expansion mechanism 24.
  • the second closing valve 26 is a valve to which a second refrigerant communication pipe 7 for exchanging refrigerant between the heat source unit 2 and the utilization units 4 and 5 is connected, and is connected to the switching mechanism 22.
  • the first and second shutoff valves 25 and 26 are three-way valves provided with service ports that can communicate with the outside of the refrigerant circuit 10.
  • the heat source unit 2 is provided with various sensors. Specifically, on the discharge side of the compressor 21, a compressor discharge pressure sensor 28 for detecting the compressor discharge pressure Pd, and a pressure A compressor discharge temperature sensor 29 for detecting the compressor discharge temperature Td is provided. In the present embodiment, the compressor discharge temperature sensor 29 is a thermistor. Further, the heat source unit 2 includes a heat source side control unit 30 that controls the operation of each unit constituting the heat source unit 2.
  • the heat source side control unit 30 includes a microcomputer memory provided for controlling the heat source unit 2, and the use side control units 46 and 56 of the use units 4 and 5. Control signals and the like can be exchanged via the transmission line 8a.
  • Refrigerant communication pipes 6 and 7 are refrigerant pipes installed on site when the air conditioner 1 is installed at the installation site.
  • the air conditioner 1 includes various types of the air conditioner 1 using the use side control units 46 and 56, the heat source side control unit 30, and the transmission line 8a that connects the control units 30, 46, and 56.
  • a control unit 8 is configured as a control means for performing operation control. The control unit 8 is connected so that it can receive the detection signals of the various sensors 29, 30, 44, 45, 54, 55, and various devices 21, 22, 24, 27, 41, 43, 51, 53 can be controlled.
  • FIG. 2 is a pressure entry ruby diagram illustrating the refrigeration cycle in the present embodiment.
  • the control in various operations described below is performed by the control unit 8 functioning as the operation control means. Specifically, the use side control units 46, 56, the heat source side control unit 33, and the control units 33, 46, 56 This is done by the transmission line 8a) connecting them.
  • the switching mechanism 22 is in the state indicated by the solid line in FIG. 1, that is, the discharge side of the compressor 21 is connected to the heat source side heat exchanger 23, and the suction side of the compressor 21 is connected to the second closing valve 26. It has become a state. The opening degrees of the heat source side expansion mechanism 24 and the use side expansion mechanisms 41 and 51 are adjusted. Moreover, the shut-off valves 25 and 26 are opened. [0020] In the state of the refrigerant circuit 10, when the compressor 21, the heat source side fan 27, and the use side fans 43, 53 are started, low-pressure refrigerant (see point A in FIG. 2) is sucked into the compressor 21. Thus, it is compressed to a pressure exceeding the critical pressure (ie, Pep in Fig.
  • the high-pressure refrigerant is sent to the heat source side heat exchanger 23 that functions as a refrigerant cooler via the switching mechanism 22 to exchange heat with the outdoor air supplied by the heat source side fan 27. (Refer to point C in Fig. 2). Then, the high-pressure refrigerant cooled in the heat source side heat exchanger 23 is sent to the utilization units 4 and 5 via the heat source side expansion mechanism 24, the first closing valve 25, and the first refrigerant communication tube 6. It is done.
  • the refrigerant sent to each of the usage units 4 and 5 is decompressed by the usage-side expansion mechanisms 41 and 51 to become low-pressure gas-liquid two-phase refrigerant (see point D in FIG. 2), and serves as a refrigerant heater.
  • the functioning use-side heat exchangers 42 and 52 heat is exchanged with room air, respectively, and they are evaporated to become low-pressure refrigerant (see point A in Fig. 2).
  • the low-pressure refrigerant heated in these use side heat exchangers 42 and 52 is sent to the heat source unit 2 via the second refrigerant communication pipe 7, and the second closing valve 26 and the switching mechanism 22 are passed through. Via, it is sucked into the compressor 21 again. In this way, cooling is performed.
  • the force S described when both of the two usage units 4 and 5 perform cooling is used when only one of the usage units 4 and 5 performs cooling.
  • the corresponding usage-side expansion mechanism has a stop opening degree (for example, fully closed), so that the refrigerant does not pass through the usage unit when the cooling is stopped!
  • the use-side expansion mechanism is not at the stop position! /
  • only the use unit is cooled.
  • cooling stopped here means not only when the user has intentionally issued a cooling stop command to the use units 4 and 5 by a remote controller or the like, but also when the thermostat is off. Even when the air condition and the air blowing state continue for a long time, the usage side expansion mechanism corresponding to the usage unit that is in the cooling stop state is at the stop opening, so this is included.
  • the switching mechanism 22 is in the state indicated by the broken line in FIG. 1, that is, the discharge side of the compressor 21 is connected to the second closing valve 26, and the suction side of the compressor 21 is connected to the heat source side heat exchanger 23. Connected. The opening degrees of the heat source side expansion mechanism 24 and the use side expansion mechanisms 41 and 51 are adjusted. Moreover, the shut-off valves 25 and 26 are opened.
  • the high-pressure refrigerant sent to each of the usage units 4 and 5 is cooled by exchanging heat with room air in the usage-side heat exchangers 42 and 52 that function as a refrigerant cooler (Fig. After passing through the use side expansion mechanism 41, 51, it is sent to the heat source unit 2 via the first refrigerant communication pipe 6.
  • the high-pressure refrigerant sent to the heat source unit 2 is reduced in pressure by the heat source side expansion mechanism 24 to become a low-pressure gas-liquid two-phase refrigerant (see point D in FIG. 2), and serves as a refrigerant heater. It flows into the side heat exchanger 23.
  • the low-pressure gas-liquid two-phase refrigerant flowing into the heat source side heat exchanger 23 evaporates by heat exchange with the outdoor air supplied by the heat source side fan 27 to become a low pressure refrigerant. (Refer to point A in FIG. 2), the air is again sucked into the compressor 21 via the switching mechanism 22. In this way, heating is performed.
  • the refrigerant in the range from the connection with the second refrigerant communication pipe 7 of the usage unit when heating is stopped to the usage side expansion mechanism is The refrigerant pressure becomes the refrigerant pressure on the high-pressure side of the refrigeration cycle operation (that is, the pressure almost the same as the refrigerant pressure at points B and C in Fig. 2), and the refrigerant temperature The temperature is close to the ambient temperature of the place where the use unit is stopped and the ambient temperature of the use side heat exchanger (in Fig. 2, the refrigerant temperature is the line connecting point B and point C.
  • the alternate long and short dash line shown in FIG. 2 is an isotherm.
  • the refrigerant stagnation amount Ms increases, and the amount of refrigerant circulating in the refrigerant circuit 10 may be insufficient. If the amount of refrigerant circulating in the refrigerant circuit 10 is insufficient, the discharge temperature of the compressor 21 for compressing the refrigerant (that is, the compressor discharge temperature Td) rises excessively, and heating cannot be continued. End up.
  • the upper limit value Tdh is set for the compressor discharge temperature Td as in the conventional case, and the compressor discharge temperature Td is set to the upper limit value Tdh.
  • the control unit temporarily increases the opening of the usage-side expansion mechanism of the user unit that is not in heating, thereby creating a refrigerant flow in the user unit that is not heating.
  • a refrigerant recovery operation (hereinafter referred to as discharge temperature upper limit control) is performed in which the refrigerant that has fallen into the unit is returned to the flow path portion where the refrigerant in the refrigerant circuit 10 circulates.
  • FIG. 3 is a flowchart of the discharge temperature upper limit control and the refrigerant stagnation amount control in the present embodiment.
  • the usage unit 4 is heating and the usage unit 5 is not heating.
  • step S1 it is determined whether or not the compressor discharge temperature Td has risen to the upper limit value Tdh. If the compressor discharge temperature Td has risen to the upper limit value Tdh, step S2 When the compressor discharge temperature Td has not risen to the upper limit value Tdh, the process proceeds to steps S6 to S10 (that is, refrigerant stagnation amount control described later). Next, in step S2, control is performed to increase the opening of the use-side expansion mechanism 51 of the use unit 5 while heating is stopped. More specifically, when the compressor discharge temperature Td rises to the upper limit value Tdh, the opening degree of the use side expansion mechanism 51 is changed to the current opening degree (for example, the stop opening degree or the refrigerant described later).
  • the current opening degree for example, the stop opening degree or the refrigerant described later.
  • the opening amount is already larger than the stop opening amount due to the stagnation amount control, the opening amount is rapidly controlled from the opening amount to a relatively large first opening amount (for example, fully open).
  • a relatively large first opening amount for example, fully open.
  • step S3 the force at which the compressor discharge temperature Td is lower than the upper limit value Tdh is determined by the process of step S2, and the compressor discharge temperature Td is lower than the upper limit value Tdh.
  • step S4 the use side expansion mechanism 51 opened to the first opening in step S2 is closed to the stop opening. Continue to heat unit 4 in use.
  • the compressor discharge temperature Td does not fall below the upper limit value Tdh, for example, a process of stopping the compressor 21 is performed from the viewpoint of protecting the compressor 21 as in step S5.
  • the discharge temperature upper limit control it is possible to eliminate the stagnation of the refrigerant in the utilization unit 5 during the heating stop mainly for the purpose of protecting the compressor 21.
  • the compressor discharge temperature Td is used as a threshold value, and the viewpoint of protecting the compressor 21 Therefore, the opening degree of the utilization side expansion mechanism of the utilization unit while heating is stopped is rapidly opened to the first opening degree, so that a refrigerant flow noise is generated in the utilization unit when heating is stopped.
  • the refrigerant pressure in the use side heat exchanger 42, 52 is critical pressure P Since it exceeds cp and is not in a gas-liquid two-phase state, it becomes possible to calculate the amount of refrigerant present in the usage units 4 and 5 from the refrigerant temperature and refrigerant pressure in the usage units 4 and 5. Using this fact, the refrigerant stagnation amount Ms of the utilization unit while heating is stopped is calculated, and the utilization side expansion mechanism of the utilization unit when heating is stopped is controlled according to the calculated refrigerant stagnation amount Ms.
  • the refrigerant stagnation amount control is performed to prevent the refrigerant amount circulating in the refrigerant circuit 10 from being insufficient and the compressor discharge temperature Td from excessively rising due to the stagnation of the refrigerant in the use unit when heating is stopped. I have to.
  • the refrigerant stagnation amount control is a control performed when the compressor discharge temperature Td has not risen to the upper limit value Tdh in step S1.
  • usage unit 4 is heating and usage unit 5 is not heating.
  • step S6 the refrigerant temperature and the refrigerant pressure in the usage unit 5 necessary for calculating the refrigerant stagnation amount Ms of the usage unit 5 during the heating stop are detected.
  • the refrigerant temperature it is desirable to use the use side heat exchanger 52 having a large volume of refrigerant in the equipment constituting the use side refrigerant circuit 10b of the use unit 5 and the refrigerant temperature in the vicinity thereof.
  • the refrigerant outlet refrigerant temperature Tho, the condenser inlet refrigerant temperature Thi, or the average temperature of the condenser outlet refrigerant temperature Tho and the condenser inlet refrigerant temperature Thi when calculating the refrigerant stagnation amount Ms, the refrigerant outlet refrigerant temperature Tho, the condenser inlet refrigerant temperature Thi, or the average temperature of the condenser outlet refrigerant temperature Tho and the condenser inlet refrigerant temperature Thi.
  • the refrigerant temperature is used as the refrigerant temperature.
  • the refrigerant pressure is based on the compressor discharge pressure Pd or the compressor discharge pressure Pd.
  • the pressure calculated in consideration of the pressure loss from the discharge side of the compressor 21 to the branch portion of the second refrigerant communication pipe 7 is used as the refrigerant pressure when calculating the refrigerant stagnation amount Ms.
  • the opening degree of the use-side expansion mechanism 51 is set to a second value slightly larger than the stop opening degree in order to increase the detection accuracy of the refrigerant temperature. It is desirable to allow the refrigerant to pass through the use unit 5 when heating is stopped by opening it to the opening.
  • the second opening is smaller than the first opening in the discharge temperature upper limit control. Then, the refrigerant temperature and refrigerant pressure detected in this way are converted into refrigerant density, and the refrigerant stagnation is based on the volume of the equipment constituting the usage side refrigerant circuit 10b of the usage unit 5 and the density of this refrigerant. Calculate the quantity Ms.
  • step S7 it is determined whether or not the refrigerant stagnation amount Ms obtained by the calculation exceeds the allowable value Msa of the refrigerant stagnation amount.
  • the allowable value Msa of the refrigerant stagnation amount is a value determined based on the total refrigerant amount enclosed in the refrigerant circuit 10 and the necessary refrigerant circulation amount according to the operating conditions of the air conditioner 1.
  • the process proceeds to step S8, and the opening degree of the utilization side expansion mechanism 51 of the utilization unit 5 during the heating stop. Is opened by a predetermined opening increment from the current opening (for example, the stop opening or the opening when the refrigerant stagnation amount control is already larger than the stop opening). .
  • the opening increment of the use side expansion mechanism 51 is smaller than the opening increment when opening to the first opening in the discharge temperature upper limit control.
  • the opening increment may be a constant value or a value that can be varied according to the deviation between the refrigerant stagnation amount Ms and the allowable value Msa.
  • step S9 the refrigerant stagnation amount Ms becomes smaller than the refrigerant stagnation amount allowable value Msa.
  • the opening degree of the use-side expansion mechanism 51 is further increased from the current opening degree by a predetermined opening degree increment.
  • the process of steps Sl, S6, S7, and S8 is repeated so as to be opened, so that the refrigerant stagnation amount Ms becomes smaller than the allowable value Msa of the refrigerant stagnation amount.
  • step S9 it is determined whether or not the opening degree of the utilization side expansion mechanism 51 of the utilization unit 5 during the heating stop is the stop opening force. Returning to the process, if it is not the stop opening (that is, if the process of step S8 has been performed at least once), the use-side expansion mechanism 51 is closed to the stop opening and the process of step S1 is performed. Return. As described above, in the present embodiment, by adopting the refrigerant stagnation amount control, the refrigerant in the refrigerant circuit 10 converts the refrigerant stagnation into the use unit during the heating stop regardless of the change in the compressor discharge temperature Td. It can be gently returned to the circulating flow path portion.
  • the discharge temperature upper limit control functions only when the refrigerant circulation amount decreases so rapidly that the refrigerant stagnation state in the use unit during the heating stop cannot be eliminated even by the refrigerant stagnation amount control.
  • the processes in steps S2 to S5 described above are hardly performed.As a result, the refrigerant stagnation amount control prevents excessive rise in the compressor discharge temperature Td due to the refrigerant stagnation phenomenon, and the heating is stopped. It is possible to suppress the generation of refrigerant flow noise in other units.
  • the air conditioner 1 of the present embodiment has the following features.
  • the refrigerant pressure in the usage-side heat exchangers 42 and 52 exceeds the critical pressure Pep and is not in a gas-liquid two-phase state.
  • the refrigerant temperature and the refrigerant pressure in the usage unit that is not heating among the usage units 4 and 5 are calculated. Based on this, the refrigerant stagnation amount Ms of the usage unit while heating is stopped is calculated, and the use side expansion mechanism of the usage unit when heating is stopped is controlled according to the calculated refrigerant stagnation amount Ms.
  • the use side expansion mechanism is compared with the case where the discharge temperature upper limit control is performed which is the refrigerant recovery operation in which the refrigerant that has stagnation in the use unit that is not heating is recovered using the discharge temperature of the compressor 21 as a threshold value. This makes it possible to finely control the air flow and to perform it slowly, so that it is possible to suppress the generation of the refrigerant flow noise in the utilization unit when the heating is stopped.
  • the air conditioner 1 of the present embodiment at least one of the inlet side of the use side heat exchangers 42 and 52 during heating and the outlet side of the use side heat exchangers 42 and 52 during heating. Since the refrigerant temperature detected by the temperature sensor (here, temperature sensors 44, 45, 54, 55) provided for the two is used for calculating the refrigerant stagnation amount Ms, the calculation accuracy of the refrigerant stagnation amount Ms is improved. Can be increased.
  • the refrigerant when detecting the refrigerant temperature in the heating-use usage unit used for calculating the refrigerant stagnation amount Ms, the refrigerant passes through the heating-use usage unit.
  • the control of the use side expansion mechanism of the usage unit when heating is stopped is performed, it is used when calculating the refrigerant stagnation amount Ms while causing the flow of refrigerant in the usage unit when heating is stopped. It becomes possible to detect the refrigerant temperature in the utilization unit when heating is stopped, and the accuracy of refrigerant temperature detection can be improved.
  • the refrigerant temperatures on the inlet side of the usage-side heat exchangers 42 and 52 during heating and the outlet side of the usage-side heat exchangers 42 and 52 during heating are used for calculating the refrigerant stagnation amount Ms.
  • the refrigerant temperature in the use side heat exchangers 42 and 52 is determined as the inlet of the use side heat exchangers 42 and 52 during heating.
  • the refrigerant stagnation amount Ms may be used instead of the refrigerant temperature at the outlet side of the use-side heat exchangers 42 and 52 during heating or in combination with these refrigerant temperatures.
  • the present invention is applied to the configuration in which the two usage units 4 and 5 are connected to the heat source unit 2 has been described.
  • the present invention is applied to a configuration in which a larger number of usage units are connected to the heat source unit.
  • the invention may be applied.
  • all use sides of the use units that are in heating stop are You may make it control the opening degree of an expansion mechanism, and you may make it control the opening degree of the utilization side expansion mechanism of a utilization unit with the largest refrigerant
  • a plurality of utilization units including a utilization side expansion mechanism and a utilization side heat exchanger are connected to a heat source unit including a compressor and a heat source side heat exchanger. It has an air conditioner that has a refrigerant circuit and can be heated by refrigeration cycle operation where the high-pressure side exceeds the critical pressure of the refrigerant, and the excessive discharge temperature of the compressor due to refrigerant stagnation. In addition to preventing the rise, it is possible to suppress the generation of refrigerant flow noise in the use unit when heating is stopped.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Air Conditioning Control Device (AREA)
  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)

Abstract

L'invention concerne un climatiseur comprenant un circuit de refroidissement constitué par des unités d'utilisation reliées à une unité source thermique et permettant de réaliser une opération de chauffage au moyen d'une opération à cycle de réfrigération dans laquelle le côté haute pression présente un dépassement de la pression critique du frigorigène. L'invention permet d'empêcher une augmentation excessive de la température d'évacuation du compresseur par liquéfaction du frigorigène, et de supprimer le bruit du flux de frigorigène produit dans une unité d'utilisation inactive en termes d'opération de chauffage. À partir de la température du frigorigène et de la pression dans l'unité d'utilisation inactive en termes d'opération de chauffage parmi les unités d'utilisation, la quantité de frigorigène liquéfié, soit la quantité de frigorigène demeurant dans l'unité d'utilisation inactive en termes d'opération de chauffage, est calculée. Selon la quantité de frigorigène liquéfié, le mécanisme de détente côté utilisation de l'unité d'utilisation inactive en termes d'opération de chauffage est commandé.
PCT/JP2007/073566 2006-12-08 2007-12-06 Climatiseur WO2008069265A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2006332648A JP4274236B2 (ja) 2006-12-08 2006-12-08 空気調和装置
JP2006-332648 2006-12-08

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Publication Number Publication Date
WO2008069265A1 true WO2008069265A1 (fr) 2008-06-12

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JP (1) JP4274236B2 (fr)
WO (1) WO2008069265A1 (fr)

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CN105556219A (zh) * 2013-09-19 2016-05-04 大金工业株式会社 制冷装置
CN110173796A (zh) * 2019-05-29 2019-08-27 南京天加环境科技有限公司 一种防止多联式空调室内机制冷剂回液的控制方法
JP2021055941A (ja) * 2019-09-30 2021-04-08 ダイキン工業株式会社 冷凍装置

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JP2016003848A (ja) * 2014-06-19 2016-01-12 日立アプライアンス株式会社 空気調和システムおよびその制御方法
JP2017172946A (ja) * 2016-03-25 2017-09-28 三菱重工サーマルシステムズ株式会社 空調運転制御装置、空調システム、空調運転制御方法及びプログラム
CN113639395B (zh) * 2021-08-05 2023-02-28 青岛海尔空调电子有限公司 多联机空调的控制方法、系统及多联机空调

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JPH0886527A (ja) * 1994-09-16 1996-04-02 Toshiba Corp 空気調和装置

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JPH07158989A (ja) * 1993-12-01 1995-06-20 Daikin Ind Ltd 多室型空気調和装置
JPH0886527A (ja) * 1994-09-16 1996-04-02 Toshiba Corp 空気調和装置

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105556219A (zh) * 2013-09-19 2016-05-04 大金工业株式会社 制冷装置
CN110173796A (zh) * 2019-05-29 2019-08-27 南京天加环境科技有限公司 一种防止多联式空调室内机制冷剂回液的控制方法
CN110173796B (zh) * 2019-05-29 2020-12-22 南京天加环境科技有限公司 一种防止多联式空调室内机制冷剂回液的控制方法
JP2021055941A (ja) * 2019-09-30 2021-04-08 ダイキン工業株式会社 冷凍装置
WO2021065118A1 (fr) * 2019-09-30 2021-04-08 ダイキン工業株式会社 Dispositif de réfrigération
CN114341571A (zh) * 2019-09-30 2022-04-12 大金工业株式会社 制冷装置
EP4015939A4 (fr) * 2019-09-30 2022-10-12 Daikin Industries, Ltd. Dispositif de réfrigération
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