WO2017026115A1 - 冷凍装置 - Google Patents

冷凍装置 Download PDF

Info

Publication number
WO2017026115A1
WO2017026115A1 PCT/JP2016/003624 JP2016003624W WO2017026115A1 WO 2017026115 A1 WO2017026115 A1 WO 2017026115A1 JP 2016003624 W JP2016003624 W JP 2016003624W WO 2017026115 A1 WO2017026115 A1 WO 2017026115A1
Authority
WO
WIPO (PCT)
Prior art keywords
temperature
cooling
compressor
refrigerant
heat exchanger
Prior art date
Application number
PCT/JP2016/003624
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
卓也 北尾
明敏 上野
宏一 北
Original Assignee
ダイキン工業株式会社
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 ダイキン工業株式会社 filed Critical ダイキン工業株式会社
Priority to EP16834816.7A priority Critical patent/EP3333503B1/de
Priority to CN201680046138.2A priority patent/CN107850347B/zh
Publication of WO2017026115A1 publication Critical patent/WO2017026115A1/ja

Links

Images

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
    • F25B49/00—Arrangement or mounting of control or safety devices
    • F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F25B49/022—Compressor control arrangements
    • 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
    • F25B2400/00—General features or devices for refrigeration machines, plants or systems, combined heating and refrigeration systems or heat-pump systems, i.e. not limited to a particular subgroup of F25B
    • F25B2400/07—Details of compressors or related parts
    • F25B2400/075—Details of compressors or related parts with parallel compressors
    • F25B2400/0751—Details of compressors or related parts with parallel compressors the compressors having different capacities
    • 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
    • F25B2600/02—Compressor control
    • F25B2600/025—Compressor control by controlling speed
    • 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
    • F25B2600/2509—Economiser valves
    • 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
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/19—Pressures
    • F25B2700/193—Pressures of the compressor
    • F25B2700/1933—Suction pressures
    • 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
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/21—Temperatures
    • F25B2700/2104—Temperatures of an indoor room or compartment
    • 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
    • F25B2700/00—Sensing or detecting of parameters; Sensors therefor
    • F25B2700/21—Temperatures
    • F25B2700/2115—Temperatures of a compressor or the drive means therefor
    • F25B2700/21151—Temperatures of a compressor or the drive means therefor at the suction side of the compressor

Definitions

  • This disclosure relates to refrigeration equipment.
  • Patent Literature 1 discloses a refrigeration apparatus including an outdoor unit having a compressor and an outdoor heat exchanger, and a cooling unit (use side unit) having a use side heat exchanger.
  • an outdoor unit and a cooling unit are connected to form a refrigerant circuit.
  • the cooling unit cools the air in the thermo-on state (the use-side heat exchanger cools the air in the cabinet) according to the temperature of the cabinet air (inner chamber temperature) detected by the cabinet temperature sensor. State) or a thermo-off state (a state in which the air in the warehouse is not cooled by the use side heat exchanger).
  • the compressor is stopped when the cooling unit is in the thermo-off state, and the compressor is activated when the cooling unit is in the thermo-on state.
  • the operating frequency of the compressor is controlled so that the temperature of the refrigerant sucked into the compressor (hereinafter referred to as “suction temperature”) becomes a predetermined target evaporation temperature. It is done.
  • the target evaporation temperature takes into account pressure loss (specifically, pipe length, pipe diameter, height difference, etc.) in the pipe between the liquid end of the use side heat exchanger and the suction port of the compressor.
  • the temperature is set to be lower than the set temperature in the cabinet.
  • the usage-side unit when the cooling operation is started, the usage-side unit is in a cooling state (a state in which the usage-side heat exchanger functions as an evaporator to cool the interior), and the internal temperature gradually decreases.
  • a predetermined period period for lowering the internal temperature
  • the internal temperature becomes a temperature in the vicinity of the internal set temperature, and the internal cooling load decreases. That is, the period after a predetermined period has elapsed since the start of the cooling operation is a period during which the internal temperature is stable near the internal set temperature and the internal cooling load is relatively low (hereinafter, It can be considered that it is described as “Low load period in the warehouse”.
  • the cooling capacity required for the usage-side unit is relatively low. Therefore, the operating frequency of the compressor is lowered to reduce the coefficient of performance (COP) of the refrigeration system. It is preferable to improve.
  • the lower the target evaporation temperature the lower the operating frequency of the compressor during the low-load period during the cooling operation, and the more difficult it is to improve the coefficient of performance of the refrigeration apparatus.
  • an object of the present disclosure is to provide a refrigeration apparatus that can improve the coefficient of performance by promoting the decrease in the operating frequency of the compressor during the low load period in the refrigerator during the cooling operation.
  • the first aspect of the present disclosure includes a heat source side unit (11) having a compressor (21a) and a heat source side heat exchanger (23), and a use side heat exchanger (51) provided in the cabinet.
  • the utilization side unit (12) In the cooling operation in which the heat source side heat exchanger (23) functions as a condenser, and the internal temperature (Tr) exceeds the internal set temperature range including the internal set temperature (Tset), the use side When the refrigerant is circulated through the heat exchanger (51) and the use-side heat exchanger (51) functions as an evaporator, the internal temperature (Tr) falls below the internal set temperature range. It will be in a dormant state in which the refrigerant flow in the usage-side heat exchanger (51) is shut off and cooling in the warehouse is suspended.
  • the target evaporation temperature (Te) is the reference temperature (Teref).
  • the target for correcting the target evaporation temperature (Te) to be higher than It is the refrigeration apparatus according to claim which comprises a temperature setting unit (84).
  • the user side in the pull-down period (PD) can be secured. Thereby, cooling in a store
  • the internal temperature (Tr) becomes a temperature in the vicinity of the internal set temperature (Tset), and the internal cooling load decreases. . That is, during the period after the pull-down period (PD) has elapsed since the start of the cooling operation, the internal temperature (Tr) is stable near the internal set temperature (Tset) and the internal cooling load is relatively low. It can be considered that the period is low (hereinafter referred to as “low load period in the warehouse”).
  • the frequency index value (FQi) in a cooling continuation period is a reference value (FQref).
  • the target evaporation temperature (Te) By adjusting the target evaporation temperature (Te) so that the target evaporation temperature (Te) is higher than the reference temperature (Teref) when the temperature exceeds, the target evaporation temperature (Te) can be increased to promote a reduction in the operating frequency (FQ) of the compressor (21a) .
  • the frequency index value (FQi) corresponds to an average value (FQave) of the operating frequency (FQ) of the compressor (21a) during the cooling duration.
  • This is a refrigeration apparatus.
  • the target temperature setting unit (84) determines in advance the average value (FQave) of the operating frequency (FQ) of the compressor (21a) during the cooling continuation period after the elapse of the pull-down period (PD). If the reference value (FQref) is exceeded, the target evaporation temperature (Te) is corrected so that the target evaporation temperature (Te) is higher than the reference temperature (Teref). As a result, when the compressor (21a) is driven at a relatively high operating frequency during the low load period in the warehouse after the pull-down period (PD) has elapsed, the target evaporation temperature (Te) is increased and compression is performed. Reduction of the operating frequency (FQ) of the machine (21a) can be promoted.
  • the frequency index value (FQi) is an operation of the compressor (21a) at a time point when the usage-side unit (12) is in a rest state from a cooling state.
  • the refrigeration apparatus corresponds to a frequency (FQ).
  • the target temperature setting unit (84) operates the operating frequency of the compressor (21a) at the time when the usage-side unit (12) goes from the cooling state to the dormant state after the pull-down period (PD) has elapsed.
  • the target evaporation temperature (Te) is corrected so that the target evaporation temperature (Te) is higher than the reference temperature (Teref).
  • the compressor (21a) is driven at a relatively high operating frequency during the low load period in the warehouse after the pull-down period (PD) has elapsed, the target evaporation temperature (Te) is increased and compression is performed. Reduction of the operating frequency (FQ) of the machine (21a) can be promoted.
  • the target temperature setting unit (84) is configured so that the target evaporation temperature (Te) is a predetermined upper limit temperature (Temax).
  • the target evaporating temperature (Te) is corrected so as not to exceed the temperature).
  • the target evaporation temperature (Te) is prevented from becoming too high by correcting the target evaporation temperature (Te) so that the target evaporation temperature (Te) does not exceed the upper limit temperature (Temax). be able to.
  • the target temperature setting unit (84) is configured so that the target evaporation temperature (Te) is higher than the reference temperature (Teref). If it is higher and the length of the cooling duration exceeds a predetermined duration threshold (Tth), the target evaporation temperature (Te) decreases and approaches the reference temperature (Teref) or
  • the refrigerating apparatus is characterized in that the target evaporation temperature (Te) is corrected so as to coincide with the reference temperature (Teref).
  • the target evaporation temperature (Te) is decreased when the length of the cooling continuation period (period in which the usage-side unit (12) is in the cooling state) exceeds the duration threshold value (Tth).
  • Tth duration threshold value
  • the cooling capacity of the usage-side unit (12) can be increased when the internal cooling load increases during the internal low load period after the pull-down period (PD) elapses.
  • the target temperature setting unit (84) is configured so that the use side heat exchanger ( 51) function as a condenser and the heat source side heat exchanger (23) functions as an evaporator.
  • the target evaporation temperature (Te) should be set to the reference temperature (Teref). It is the freezing apparatus characterized.
  • the sixth aspect it is possible to ensure the heat dissipation capability of the user side unit (12) (specifically, the heat dissipation capability of the user side heat exchanger (51)) in the defrosting operation.
  • the pull-down period (PD) is set so that the usage-side unit (12) is in a cooled state from the start of the cooling operation.
  • a refrigeration apparatus that corresponds to a shorter period of a period up to a time point when the cooling operation is started and a period until a predetermined time (T1) elapses from the start time of the cooling operation. It is.
  • the internal temperature (Tr) becomes a temperature in the vicinity of the internal set temperature (Tset). Can be considered. In addition, even if a sufficient time (that is, the predetermined time (T1)) has elapsed after the start of the cooling operation, it is considered that the internal temperature (Tr) is close to the internal set temperature (Tset). Can do.
  • the fourth aspect of the present disclosure it is possible to prevent the target evaporation temperature (Te) from becoming too high. Therefore, the cooling capacity of the user side unit (12) due to the increase in the target evaporation temperature (Te). Can be prevented.
  • the cooling capacity of the use side unit (12) is increased when the cooling load in the warehouse becomes high during the low load period in the warehouse after the lapse of the pull-down period (PD). Therefore, the internal temperature (Tr) can be quickly brought close to the internal set temperature (Tset).
  • the sixth aspect of the present disclosure it is possible to ensure the heat radiation capability of the usage-side unit (12) in the defrosting operation, so that the defrosting of the usage-side heat exchanger (51) is appropriately performed in the defrosting operation. It can be carried out.
  • the period from the start time of the cooling operation to the time point when the user side unit (12) enters the dormant state from the cooling state and the predetermined time (T1) from the start time of the cooling operation are By setting the shorter of the period up to the time point as the pull-down period (PD), the internal temperature (Tr) is decreased in the pull-down period (DP) and the internal temperature (Tr) is set to the internal set temperature.
  • the temperature can be in the vicinity of (Tset).
  • FIG. 1 is a piping diagram illustrating a configuration example of a refrigeration apparatus according to an embodiment.
  • FIG. 2 is a flowchart showing the operation of the refrigeration apparatus.
  • FIG. 3 is a piping diagram showing the refrigerant flow in the cooling operation.
  • FIG. 4 is a piping diagram showing the refrigerant flow in the defrosting operation.
  • FIG. 5 is a flowchart for explaining the operation of the target temperature setting unit in the cooling operation.
  • FIG. 6 is a graph for explaining the frequency index value.
  • FIG. 7 is a graph for explaining a change in the internal temperature.
  • FIG. 8 is a graph for explaining a change in the operating frequency of the compressor in the comparative example of the refrigeration apparatus.
  • FIG. 9 is a graph for explaining a change in the operating frequency of the compressor in the refrigeration apparatus according to the embodiment.
  • FIG. 1 shows a configuration example of a refrigeration apparatus (10) according to an embodiment.
  • the refrigeration apparatus (10) includes a heat source side unit (11) provided outside the storage, a use side unit (12) provided in a storage such as a refrigerator or a freezer, and a controller (80).
  • the heat source side unit (11) includes a heat source side circuit (16) and a heat source side fan (17)
  • the usage side unit (12) includes a usage side circuit (18), a usage side fan (19), and Is provided.
  • the heat source side circuit (16) of the heat source side unit (11) and the usage side circuit (18) of the usage side unit (12) are connected to the liquid side communication pipe (13) and the gas side communication pipe ( 14), a refrigerant circuit (15) in which a refrigerant circulates and a vapor compression refrigeration cycle is performed is configured.
  • a liquid closing valve (V1) and a gas closing valve (V2) are provided at the liquid end and the gas end of the heat source side circuit (16), respectively, and the liquid closing valve (V1) and the gas closing valve (V2)
  • One end of the liquid side connecting pipe (13) and one end of the gas side connecting pipe (14) are connected to the liquid side connecting pipe (13) and the gas side connecting pipe (14), respectively. Each gas end is connected.
  • the heat source side circuit (16) includes first and second compressors (21a, 21b), a four-way switching valve (22), a heat source side heat exchanger (23), a supercooling heat exchanger (24), A supercooling expansion valve (31), an intermediate expansion valve (32), an intermediate on-off valve (33), an intermediate check valve (34), a receiver (35), a heat source side expansion valve (36), 1, second and third check valves (CV1, CV2, CV3), first and second oil separators (OSa, OSb), first and second discharge check valves (CVa, CVb), It has first and second capillary tubes (CTa, CTb) and an oil separation check valve (CVc).
  • the heat source side circuit (16) includes a discharge refrigerant pipe (41), an intake refrigerant pipe (42), a heat source side liquid refrigerant pipe (43), an injection pipe (44), and first and second connections. Pipes (45, 46) and an oil return pipe (47) are provided.
  • the first compressor (21a) is configured to compress and discharge the sucked refrigerant.
  • the first compressor (21a) is provided with a suction port, an intermediate port, and a discharge port.
  • the suction port is formed so as to communicate with the compression chamber (that is, the low-pressure compression chamber) in the suction stroke of the first compressor (21a).
  • the intermediate port is formed so as to communicate with the compression chamber (that is, the compression chamber of intermediate pressure) during the compression stroke of the first compressor (21a).
  • the discharge port is configured to communicate with the compression chamber (that is, the high-pressure compression chamber) in the discharge stroke of the first compressor (21a).
  • the first compressor (21a) is configured by a scroll compressor in which a compression chamber is formed between a fixed scroll and a movable scroll that mesh with each other.
  • the second compressor (21b) has a configuration similar to that of the first compressor (21a).
  • the first compressor (21a) has a variable operating frequency (capacity).
  • the first compressor (21a) is configured such that by changing the output frequency of the inverter (not shown), the rotational speed of the motor provided therein changes, and the operating frequency changes. ing.
  • the operating frequency (capacity) of the second compressor (21b) is fixed. That is, as for the 2nd compressor (21b), the rotation speed of the electric motor provided in the inside is constant, and the operating frequency is constant.
  • the four-way switching valve (22) includes a first state (state indicated by a solid line in FIG. 1) in which the first port and the third port communicate with each other and the second port and the fourth port communicate with each other, And the fourth port are in communication with each other and the second port and the third port are in communication with each other (a state indicated by a broken line in FIG. 1).
  • the first port of the four-way switching valve (22) is connected to the discharge ports of the first and second compressors (21a, 21b) by the discharge refrigerant pipe (41), and the second port of the four-way switching valve (22) is
  • the suction refrigerant pipe (42) is connected to the suction ports of the first and second compressors (21a, 21b).
  • the third port of the four-way switching valve (22) is connected to the gas end of the heat source side heat exchanger (23), and the fourth port of the four-way switching valve (22) is connected to the gas closing valve (V2). .
  • the discharge refrigerant pipe (41) has first and second discharge pipes (41a, 41b) whose one ends are connected to discharge ports of the first and second compressors (21a, 21b), and first and second discharge pipes. It is comprised by the discharge main pipe (41c) which connects the other end of (41a, 41b) and the 1st port of the four-way selector valve (22).
  • the suction refrigerant pipe (42) has first and second suction pipes (42a, 42b) connected at one end to the suction ports of the first and second compressors (21a, 21b), respectively, and the first and second suction pipes.
  • the suction main pipe (42c) connects the other end of the pipe (42a, 42b) and the second port of the four-way selector valve (22).
  • the liquid end of the heat source side heat exchanger (23) is connected to one end of the heat source side liquid refrigerant pipe (43), and the gas end is connected to the third port of the four-way switching valve (22).
  • the heat source side fan (17) is arrange
  • the heat source side heat exchanger (23) is configured to exchange heat between the refrigerant and the heat source side air (that is, outside air) conveyed by the heat source side fan (17).
  • the heat source side heat exchanger (23) is configured by a cross-fin type fin-and-tube heat exchanger.
  • the heat source side liquid refrigerant pipe (43) includes a first heat source side liquid pipe (43a) that connects the liquid end of the heat source side heat exchanger (23) and the receiver (35), and a receiver (35).
  • a first heat source side liquid pipe (43a) that connects the liquid end of the heat source side heat exchanger (23) and the receiver (35), and a receiver (35).
  • the injection pipe (44) connects the first intermediate part (Q1) of the heat source side liquid refrigerant pipe (43) and the intermediate ports of the first and second compressors (21a, 21b).
  • the injection pipe (44) includes a first injection main pipe (44m) that connects the first intermediate part (Q1) of the heat source side liquid refrigerant pipe (43) and the supercooling heat exchanger (24), and one end.
  • the second injection main pipe (44n) connected to the supercooling heat exchanger (24), the other end of the second injection main pipe (44n), and the intermediate ports of the first and second compressors (21a, 21b).
  • the first and second injection branch pipes (44a, 44b) are connected to each other.
  • the supercooling heat exchanger (24) is connected to the heat source side liquid refrigerant pipe (43) and the injection pipe (44), and includes a refrigerant flowing through the heat source side liquid refrigerant pipe (43) and a refrigerant flowing through the injection pipe (44).
  • the supercooling heat exchanger (24) includes a first flow path (24a) connected between the second heat source side liquid pipe (43b) and the third heat source side liquid pipe (43c), The second flow path (24b) connected between the 1 injection main pipe (44m) and the second injection main pipe (44n), and the refrigerant flowing through the first flow path (24a) and the second flow path (24b )
  • the supercooling heat exchanger (24) is configured by a plate heat exchanger.
  • the supercooling expansion valve (31) is located between the first intermediate part (Q1) of the heat source side liquid refrigerant pipe (43) and the supercooling heat exchanger (24) in the injection pipe (44) (in this example, the first It is provided in the injection main pipe (44m). Further, the supercooling expansion valve (31) is configured such that its opening degree can be adjusted.
  • the supercooling expansion valve (31) is constituted by an electronic expansion valve (motorized valve).
  • the intermediate expansion valve (32) is located between the supercooling heat exchanger (24) and the intermediate port of the first compressor (21a) in the injection pipe (44) (in this example, the first injection branch pipe (44a)). Is provided. Further, the intermediate expansion valve (32) is configured so that its opening degree can be adjusted. For example, the intermediate expansion valve (32) is configured by an electronic expansion valve (motorized valve).
  • the intermediate on-off valve (33) and the intermediate check valve (34) are disposed between the supercooling heat exchanger (24) and the intermediate port of the second compressor (21b) in the injection pipe (44) (in this example, the first 2 injection branch pipe (44b)).
  • an intermediate on-off valve (33) and an intermediate check valve (34) are sequentially arranged from the inlet side to the outlet side of the second injection branch pipe (44b).
  • the intermediate on-off valve (33) is configured to be switchable.
  • the intermediate opening / closing valve (33) is constituted by a solenoid valve.
  • the intermediate check valve (34) is configured to allow the refrigerant flow from the inlet side to the outlet side of the second injection branch pipe (44b) and to block the refrigerant flow in the reverse direction.
  • the receiver (35) is connected between the heat source side heat exchanger (23) and the supercooling heat exchanger (24) in the heat source side liquid refrigerant pipe (43), and is connected to a condenser (specifically, heat source side heat The refrigerant condensed in the exchanger (23) or a later-described use side heat exchanger (51)) can be temporarily stored.
  • the receiver (35) has a first heat source side liquid pipe (43a) connected to the inlet and a second heat source side liquid pipe (43b) connected to the outlet.
  • the first connection pipe (45) connects the second midway part (Q2) and the third midway part (Q3) of the heat source side liquid refrigerant pipe (43).
  • the second halfway part (Q2) is located between the first halfway part (Q1) and the liquid shut-off valve (V1) in the heat source side liquid refrigerant pipe (43), and the third halfway part (Q3) is located on the heat source side It is located between the liquid end of the heat source side heat exchanger (23) and the receiver (35) in the liquid refrigerant pipe (43).
  • the second connection pipe (46) connects the fourth midway part (Q4) and the fifth midway part (Q5) of the heat source side liquid refrigerant pipe (43).
  • the fourth midway part (Q4) is located between the first halfway part (Q1) and the second halfway part (Q2) in the heat source side liquid refrigerant pipe (43), and the fifth halfway part (Q5) is located on the heat source side
  • the liquid refrigerant pipe (43) is located between the liquid end of the heat source side heat exchanger (23) and the third midway part (Q3).
  • the heat source side expansion valve (36) is provided in the second connection pipe (46). Moreover, the heat source side expansion valve (36) is comprised so that the opening degree can be adjusted.
  • the heat source side expansion valve (36) is configured by an electronic expansion valve (motorized valve).
  • the first check valve (CV1) is provided between the third midway part (Q3) and the fifth midway part (Q5) of the heat source side liquid refrigerant pipe (43), and the first check valve (CV1) 3.
  • the refrigerant flow toward the middle part (Q3) is allowed and the refrigerant flow in the opposite direction is blocked.
  • the second check valve (CV2) is provided between the second midway part (Q2) and the fourth midway part (Q4) of the heat source side liquid refrigerant pipe (43), and the second midway part (Q4) to the second midway part (Q4). 2
  • the refrigerant flow toward the middle part (Q2) is allowed and the refrigerant flow in the opposite direction is blocked.
  • the third check valve (CV3) is provided in the first connection pipe (45), and the refrigerant flows from the second midway part (Q2) to the third midway part (Q3) of the heat source side liquid refrigerant pipe (43). And the refrigerant flow in the opposite direction is blocked.
  • First oil separator and first discharge check valve are disposed between the first compressor (21a) and the first port of the four-way switching valve (22) in the discharge refrigerant pipe (41) (specifically Specifically, it is provided in the first discharge pipe (41a).
  • a first oil separator (OSa) and a first discharge check valve (CVa) are sequentially arranged from the inlet side to the outlet side of the first discharge pipe (41a).
  • the first oil separator (OSa) is configured to separate the refrigerating machine oil from the refrigerant discharged from the first compressor (21a) and store it inside.
  • the first discharge check valve (CVa) is configured to allow the flow of the refrigerant from the inlet side to the outlet side of the first discharge pipe (41a) and prevent the refrigerant flow in the reverse direction.
  • the second oil separator (OSb) is disposed between the second compressor (21b) and the first port of the four-way switching valve (22) in the discharge refrigerant pipe (41) (specifically, the second discharge pipe (41b )).
  • a second oil separator (OSb) and a second discharge check valve (CVb) are sequentially arranged from the inlet side to the outlet side of the second discharge pipe (41b).
  • the second oil separator (OSb) is configured so that the refrigeration oil can be separated from the refrigerant discharged from the second compressor (21b) and stored inside.
  • the second discharge check valve (CVb) is configured to allow the refrigerant flow from the inlet side to the outlet side of the second discharge pipe (41b) and to block the refrigerant flow in the reverse direction.
  • the oil return pipe (47) is a pipe for supplying the refrigeration oil stored in the first and second oil separators (OSa, OSb) to the injection pipe (44).
  • the oil return pipe (47) includes first and second oil return pipes (47a, 47b) whose one ends are connected to the first and second oil separators (OSa, OSb), and the first and second oil return pipes (47). 2.
  • Oil return main pipe (47c) connecting the other end of the oil return pipe (47a, 47b) and the middle part of the injection pipe (44) (specifically, the middle part (Q6) of the second injection main pipe (44n)) )
  • the middle part (Q6) of the second injection main pipe (44n) and.
  • the first capillary tube (CTa) is located between the first oil separator (OSa) and the middle part (Q6) of the injection pipe (44) in the oil return pipe (47) (specifically, the first oil return pipe). (47a)).
  • the second capillary tube (CTb) and oil return check valve (CVc) are located between the second oil separator (OSb) and the middle part (Q6) of the injection pipe (44) in the oil return pipe (47). Specifically, the second oil return pipe (47b) is provided. In the second oil return pipe (47b), an oil return check valve (CVc) and a second capillary tube (CTb) are sequentially arranged from the inlet side to the outlet side of the second oil return pipe (47b). .
  • the oil return check valve (CVc) is configured to allow the refrigerant flow from the inlet side to the outlet side of the second oil return pipe (47b) and to block the refrigerant flow in the reverse direction.
  • the utilization side circuit (18) includes a utilization side heat exchanger (51), a utilization side on-off valve (52), a utilization side expansion valve (53), and a utilization side check valve (54). . Further, the use side circuit (18) is provided with a use side liquid refrigerant pipe (61), a use side gas refrigerant pipe (62), and a bypass pipe (63).
  • the liquid end of the use side heat exchanger (51) is connected to the liquid side connection pipe (13) by the use side liquid refrigerant pipe (61), and the gas end is connected to the gas side by the use side gas refrigerant pipe (62). Connected to pipe (14).
  • the utilization side fan (19) is arrange
  • the use side heat exchanger (51) is configured to exchange heat between the refrigerant and the use side air (that is, the internal air) conveyed by the use side fan (19).
  • the use side heat exchanger (51) is configured by a cross-fin type fin-and-tube heat exchanger.
  • One end of the use side liquid refrigerant pipe (61) is connected to the liquid side connecting pipe (13), and the other end is connected to the liquid end of the use side heat exchanger (51).
  • the use side gas refrigerant pipe (62) has one end connected to the gas end of the use side heat exchanger (51) and the other end connected to the gas side communication pipe (14).
  • the use side on-off valve (52) and the use side expansion valve (53) are provided in the use side liquid refrigerant pipe (61).
  • a use side on-off valve (52) and a use side expansion valve (53) are arranged in this order from one end side to the other end side of the use side liquid refrigerant pipe (61). .
  • the use side on-off valve (52) is configured to be switchable.
  • the use side on-off valve (52) is constituted by a solenoid valve.
  • the use side expansion valve (53) is configured such that its opening degree can be adjusted.
  • the use side expansion valve (53) is constituted by an external pressure equalization type temperature automatic expansion valve. That is, the use side expansion valve (53) includes a temperature sensing cylinder (53a) provided in the use side gas refrigerant pipe (62) and a pressure equalizing pipe (not shown) connected to the middle part of the use side gas refrigerant pipe (62). The opening degree is adjusted according to the temperature of the temperature sensing cylinder (53a) and the refrigerant pressure of the pressure equalizing pipe.
  • bypass pipe (63) One end of the bypass pipe (63) is connected to a midway part between the use side expansion valve (53) and the use side heat exchanger (51) in the use side liquid refrigerant pipe (61), and the other end is used.
  • the liquid refrigerant pipe (61) is connected to a midway part between the liquid side connecting pipe (13) and the use side on-off valve (52).
  • the use-side check valve (54) is provided in the bypass pipe (63) and allows the refrigerant to flow from the use-side heat exchanger (51) side to the liquid-side connecting pipe (13) side, and in the opposite direction. It is configured to block the flow of the refrigerant.
  • the refrigeration apparatus (10) is provided with various sensors such as an intake temperature sensor (71), an intake pressure sensor (72), and an internal temperature sensor (76).
  • the suction temperature sensor (71) is configured to detect the temperature of the refrigerant sucked into the first and second compressors (21a, 21b) (hereinafter referred to as “suction temperature”).
  • suction temperature the temperature of the refrigerant sucked into the first and second compressors (21a, 21b)
  • the suction temperature sensor (71) is installed in the suction main pipe (42c) and detects the refrigerant temperature at the installation location as the suction temperature.
  • the suction pressure sensor (72) is configured to detect the pressure of the refrigerant sucked into the first and second compressors (21a, 21b) (hereinafter referred to as “suction pressure”).
  • suction pressure the pressure of the refrigerant sucked into the first and second compressors (21a, 21b)
  • the suction pressure sensor (72) is installed in the suction main pipe (42c) and detects the refrigerant pressure at the installation location as the suction pressure.
  • the internal temperature sensor (76) is configured to detect the temperature of the air in the internal space (hereinafter referred to as “internal temperature (Tr)”).
  • the internal temperature sensor (76) is installed downstream of the air flow of the usage-side fan (19) in the usage-side unit (12), and detects the air temperature at the installation location as the internal temperature (Tr). To do.
  • the controller (80) controls the operation of the refrigeration apparatus (10) by controlling each part of the refrigeration apparatus (10) based on the detection values of the various sensors.
  • the controller (80) includes a main controller (81) provided in the heat source side unit (11) and a use side controller (86) provided in the use side unit (12).
  • the main controller (81) controls the components provided in the heat source side unit (11).
  • the main controller (81) includes an operation control unit (82), a compressor control unit (83), and a target temperature setting unit (84).
  • the operation control unit (82) includes a heat source side fan (17) and various valves (in this example, a four-way switching valve (22), a supercooling expansion valve (31), and an intermediate expansion valve provided in the heat source side unit (11). (32) and intermediate on-off valve (33)) are controlled.
  • the compressor control unit (83) controls the first and second compressors (21a, 21b).
  • the target temperature setting unit (84) sets a target evaporation temperature (Te) described later.
  • the use side controller (86) controls the components (in this example, the use side fan (19) and the use side on-off valve (52)) provided in the use side unit (12).
  • the use side controller (86) determines whether or not the operation of the refrigeration apparatus (10) should be started, and if it determines that the operation of the refrigeration apparatus (10) should be started, the cooling operation (cools the inside of the refrigerator). For starting the operation) and an operation start signal is transmitted to the main controller (81). Further, the use-side controller (86) determines whether or not the operation of the refrigeration apparatus (10) should be ended, and if it determines that the operation of the refrigeration apparatus (10) should be ended, the operation for the cooling operation is performed. At the same time, an operation end signal is transmitted to the main controller (81). For example, the usage-side controller (86) determines the operation start and operation end of the refrigeration apparatus (10) in response to an operation by the user (operation for instructing operation start and operation end).
  • the use side controller (86) determines whether or not to start the defrosting operation (operation for defrosting the use side heat exchanger (51)) during the period in which the cooling operation is performed, When it is determined that the defrosting operation should be started, an operation for the defrosting operation is started and a defrosting start signal is transmitted to the main controller (81). In addition, the use side controller (86) determines whether or not the defrosting operation should be terminated during the period during which the defrosting operation is performed, and determines that the defrosting operation should be terminated. And the operation for cooling operation is started, and a defrosting end signal is transmitted to the main controller (81).
  • the use side controller (86) determines that the defrosting operation should be started after a predetermined time (cooling operation time) has elapsed from the time when the cooling operation is started, and starts the defrosting operation.
  • a predetermined time defrosting operation time
  • the target temperature setting unit (84) receives the operation start signal from the use side controller (86), the target temperature setting unit (84) sets the target evaporation temperature (Te) to a predetermined reference temperature (Teref).
  • the target evaporation temperature (Te) is a target temperature set with respect to the temperature of the refrigerant sucked into the first and second compressors (21a, 21b).
  • the reference temperature (Teref) is set to a temperature lower than the internal set temperature (Tset).
  • the internal set temperature (Tset) is a target temperature set for the internal temperature (Tr).
  • the reference temperature (Teref) is the pressure loss (specifically, the pressure loss in the pipe between the liquid end of the use side heat exchanger (51) and the suction ports of the first and second compressors (21a, 21b). It is preferable to set in consideration of pipe length, pipe diameter, height difference, and the like. Specifically, the reference temperature (Teref) is obtained by subtracting a predetermined temperature (for example, a temperature included in a range from 10 ° C. to 17 ° C.) from the internal set temperature (Tset). Is set.
  • a predetermined temperature for example, a temperature included in a range from 10 ° C. to 17 ° C.
  • the main controller (81) and the use side controller (86) control each part of the refrigeration apparatus (10) so that the cooling operation is performed in the refrigeration apparatus (10).
  • the heat source side heat exchanger (23) serves as a condenser
  • the supercooling heat exchanger (24) serves as a subcooler
  • the use side heat exchanger (51) serves as an evaporator. Is performed to cool the interior.
  • the refrigerant flow in the refrigerant circuit (15) during the cooling operation and the operation of the target temperature setting unit (84) during the cooling operation will be described in detail later.
  • the operation control unit (82) When the operation control unit (82) receives the operation start signal (or defrosting end signal) from the use side controller (86), the operation control unit (82) sets the four-way switching valve (22) to the first state, and the heat source side fan ( 17) is set to the drive state. Further, the operation control unit (82) is configured so that the degree of supercooling of the refrigerant in the supercooling heat exchanger (24) (specifically, the refrigerant at the outlet of the first flow path (24a) of the supercooling heat exchanger (24)).
  • the degree of superheat of the refrigerant discharged from the first compressor (21a) is determined in advance by adjusting the opening degree of the supercooling expansion valve (31) so that the degree of supercooling of the refrigerant reaches a predetermined target supercooling degree.
  • the opening degree of the intermediate expansion valve (32) is adjusted so as to achieve the target superheat degree.
  • the operation control unit (82) sets the intermediate on-off valve (33) to an open state and sets the heat source side expansion valve (36) to a fully closed state.
  • a compressor control part (83) will drive a 1st and 2nd compressor (21a, 21b), if the operation start signal (or defrost end signal) from a utilization side controller (86) is received.
  • the compressor control unit (83) is configured to output the first and second compressors when the refrigerant pressure (that is, the suction pressure) detected by the suction pressure sensor (72) exceeds a predetermined low pressure range. (21a, 21b) is set to the driving state, and when the suction pressure falls below the low pressure range, the first and second compressors (21a, 21b) are set to the stopped state.
  • the low pressure range will be described in detail later.
  • the compressor control unit (83) the refrigerant temperature (that is, the suction temperature) detected by the suction temperature sensor (71) becomes the target evaporation temperature (Te) set by the target temperature setting unit (84).
  • the operating frequency (FQ) of the first compressor (21a) is controlled.
  • the compressor control unit (83) increases the operating frequency (FQ) of the first compressor (21a) when the suction temperature is higher than the target evaporation temperature (Te).
  • the suction temperature can be lowered to bring the suction temperature closer to the target evaporation temperature (Te).
  • the compressor control unit (83) reduces the operating frequency (FQ) of the first compressor (21a) when the suction temperature is lower than the target evaporation temperature (Te). Thereby, the suction temperature can be raised to bring the suction temperature closer to the target evaporation temperature (Te).
  • the use side controller (86) determines that the operation of the refrigeration apparatus (10) should be started (or the defrosting operation should be ended), the use side fan (19) is set to the driving state.
  • the use side controller (86) is configured such that the temperature of the air detected by the internal temperature sensor (76) (that is, the internal temperature (Tr)) includes the internal set temperature (Tset).
  • the set temperature (Tset) for example, a temperature range having a median value in the chamber
  • the use side on-off valve (52) is set in an open state to allow the refrigerant to flow through the use side heat exchanger (51). .
  • a use side heat exchanger (51) functions as an evaporator.
  • the use side controller (86) sets the use side on-off valve (52) to the closed state when the inside temperature (Tr) falls below the set temperature range inside the compartment, and the use side heat exchanger (51) Block the flow of refrigerant.
  • the use side unit (12) causes the use side heat exchanger (51) to circulate the refrigerant when the internal temperature (Tr) exceeds the internal set temperature range in the cooling operation.
  • the exchanger (51) functions as an evaporator and becomes in a cooling state, and the internal temperature (Tr) is below the internal set temperature range, the refrigerant flow in the use side heat exchanger (51) is shut off It will be in the dormant state which stops cooling of.
  • the temperature of the temperature sensing tube (53a) and the pressure equalizing pipe (not shown) are set so that the superheat degree of the refrigerant at the outlet of the use side heat exchanger (51) becomes a predetermined superheat degree. ) Of the use side expansion valve (53) changes according to the refrigerant pressure.
  • Step (ST12) The use side controller (86) determines whether or not the defrosting operation should be started in the cooling operation period (period in which the cooling operation is performed). And if a use side controller (86) determines with the defrost operation being started, it will transmit a defrost start signal to a main controller (81). Next, the process proceeds to step (ST13).
  • the target temperature setting unit (84) receives the defrosting start signal from the use side controller (86), the target temperature setting unit (84) sets the target evaporation temperature (Te) to the reference temperature (Teref). That is, the target temperature setting unit (84) sets the target evaporation temperature (Te) to the reference temperature (Teref) after the cooling operation is completed and before the defrosting operation is started.
  • the main controller (81) and the use side controller (86) control each part of the refrigeration apparatus (10) so that the defrosting operation is performed in the refrigeration apparatus (10).
  • the defrosting operation in the refrigerant circuit (20), a refrigeration cycle is performed in which the use side heat exchanger (51) serves as a condenser and the heat source side heat exchanger (23) serves as an evaporator, and the use side heat exchanger (51). Is defrosted.
  • the refrigerant flow in the refrigerant circuit (15) during the defrosting operation will be described in detail later.
  • the operation control unit (82) When the operation control unit (82) receives the defrosting start signal from the use side controller (86), the four-way switching valve (22) is set to the second state and the heat source side fan (17) is set to the driving state. To do.
  • the operation control unit (82) sets the supercooling expansion valve (31) and the intermediate expansion valve (32) to a fully closed state, sets the intermediate on-off valve (33) to a closed state, and heat source side heat exchanger
  • the opening degree of the heat source side expansion valve (36) is adjusted so that the superheat degree of the refrigerant at the outlet of (23) becomes a predetermined target superheat degree.
  • the compressor control unit (83) sets the first and second compressors (21a, 21b) to the driving state when receiving the defrosting start signal from the use side controller (86).
  • the temperature of the refrigerant detected by the intake temperature sensor (71) (that is, the intake temperature) is set by the target temperature setting unit (84).
  • the operating frequency (FQ) of the first compressor (21a) is controlled so as to reach the target evaporation temperature (Te).
  • the use side controller (86) determines that the defrosting operation should be started, it sets the use side fan (19) to a stopped state. Moreover, a utilization side controller (86) sets a utilization side on-off valve (52) to an open state, and distribute
  • a utilization side controller (86) determines whether a defrost operation should be complete
  • the refrigerant flow in the refrigerant circuit (15) during the cooling operation will be described with reference to FIG.
  • the four-way selector valve (22) is set to the first state, and the discharge ports of the first and second compressors (21a, 21b) communicate with the gas ends of the heat source side heat exchanger (23), The suction ports of the first and second compressors (21a, 21b) communicate with the gas side communication pipe (14).
  • the refrigerant discharged from the first and second compressors (21a, 21b) is discharged from the first and second oil separators (OSa, OSb) and the first and second discharge check valves (41) in the discharge refrigerant pipe (41). CVa, CVb), and then passes through the four-way switching valve (22) and flows into the heat source side heat exchanger (23).
  • the heat source side heat exchanger (23) In the heat source side heat exchanger (23), the heat source side air (that is, outside air) ) To dissipate heat and condense.
  • the refrigerant (high-pressure refrigerant) flowing out from the heat source side heat exchanger (23) passes through the first check valve (CV1) in the first heat source side liquid pipe (43a), and then the receiver (35) and the second heat source side.
  • a refrigerant (passing through the liquid pipe (43b) in order and flowing into the first flow path (24a) of the supercooling heat exchanger (24) and flowing through the second flow path (24b) of the supercooling heat exchanger (24) (
  • the refrigerant is absorbed by the intermediate pressure refrigerant) and supercooled.
  • the refrigerant flowing out of the first flow path (24a) of the supercooling heat exchanger (24) flows into the third heat source side liquid pipe (43c), and part of it flows into the first injection main pipe (44m),
  • the remaining portion passes through the second check valve (CV2) in the third heat source side liquid pipe (43c), then passes through the liquid closing valve (V1) and flows into the liquid side connecting pipe (13).
  • the refrigerant flowing into the first injection main pipe (44m) is depressurized in the supercooling expansion valve (31), flows into the second flow path (24b) of the supercooling heat exchanger (24), and then enters the supercooling heat exchanger ( Heat is absorbed from the refrigerant (high-pressure refrigerant) flowing through the first flow path (24a) of 24).
  • the refrigerant flowing out from the second flow path (24b) of the supercooling heat exchanger (24) passes through the second injection main pipe (44n), and part of it flows into the first injection branch pipe (44a). The remaining part flows into the second injection branch pipe (44b).
  • the refrigerant flowing into the first injection branch pipe (44a) is decompressed by the intermediate expansion valve (32) and flows into the intermediate port of the first compressor (21a).
  • the refrigerant flowing into the second injection branch pipe (44b) sequentially passes through the intermediate opening / closing valve (33) and the intermediate check valve (34) and flows into the intermediate port of the second compressor (21b).
  • the refrigerant that has passed through the intermediate port and has flowed into the first and second compressors (21a, 21b) is the refrigerant in the first and second compressors (21a, 21b) (specifically, the refrigerant in the compression chamber). ). That is, the refrigerant in the first and second compressors (21a, 21b) is compressed while being cooled.
  • the refrigerant flowing into the liquid side communication pipe (13) passes through the open use side on-off valve (52) in the use side liquid refrigerant pipe (61) of the use side unit (12) and passes through the use side expansion valve (52). 53), the pressure is reduced and flows into the use-side heat exchanger (51), and the use-side heat exchanger (51) absorbs heat from the use-side air (that is, the internal air) to evaporate. Thereby, utilization side air is cooled.
  • the refrigerant flowing out of the use side heat exchanger (51) is divided into the use side gas refrigerant pipe (62), the gas side connecting pipe (14), the gas shutoff valve (V2) and the four-way switching valve (22) of the heat source side unit (11). ) And the suction refrigerant pipe (42) in order, and is sucked into the suction ports of the first and second compressors (21a, 21b).
  • the refrigeration oil is separated from the refrigerant (that is, the refrigerant discharged from the first and second compressors (21a, 21b)). It is stored in the first and second oil separators (OSa, OSb).
  • the refrigerating machine oil stored in the first oil separator (OSa) flows into the oil return main pipe (47c) after passing through the first capillary tube (CTa) in the first oil return pipe (47a).
  • the refrigerating machine oil stored in the second oil separator (OSb) passes through the oil return check valve (CVc) and the second capillary tube (CTb) in order in the second oil return pipe (47b), and then returns to the oil. It flows into the main pipe (47c).
  • the refrigeration oil that has flowed into the oil return main pipe (47c) flows into the second injection main pipe (44n) and merges with the refrigerant flowing through the second injection main pipe (44n).
  • the refrigerant discharged from the first and second compressors (21a, 21b) is discharged from the first and second oil separators (OSa, OSb) and the first and second discharge check valves (41) in the discharge refrigerant pipe (41).
  • the gas After passing through CVa, CVb), the gas passes through the four-way switching valve (22) and the gas shut-off valve (V2) in order, and flows into the gas side connecting pipe (14).
  • the refrigerant that has flowed into the gas side communication pipe (14) passes through the use side gas refrigerant pipe (62) of the use side unit (12) and flows into the use side heat exchanger (51). 51) dissipates heat and condenses. Thereby, the frost adhering to the use side heat exchanger (51) is heated and melted.
  • a part of the refrigerant flowing out of the use side heat exchanger (51) passes between the open use side expansion valve (53) and the open use side on-off valve (52) in the use side liquid refrigerant pipe (61). Passing in order, the remainder passes through the use side check valve (54) in the bypass pipe (63).
  • the refrigerant that has passed through the open-side use-side on-off valve (52) in the use-side liquid refrigerant pipe (61) joins the refrigerant that has passed through the use-side check valve (54) in the bypass pipe (63), and communicates with the liquid side. It flows into the pipe (13).
  • the refrigerant that has passed through the liquid side connecting pipe (13) passes through the liquid closing valve (V1) of the heat source side unit (11) and flows into the third heat source side liquid pipe (43c).
  • the refrigerant that has flowed into the third heat source side liquid pipe (43c) flows into the first connection pipe (45) in the second midway part (Q2), and the second check valve (CV2) in the first connection pipe (45). And flows into the midway part (third midway part (Q3)) of the first heat source side liquid pipe (43a).
  • the refrigerant that has flown into the middle of the first heat source side liquid pipe (43a) passes through the receiver (35), the second heat source side liquid pipe (43b), and the first flow path (24a) of the supercooling heat exchanger (24). And then flows into the third heat source side liquid pipe (43c).
  • the refrigerant that has flowed into the third heat source side liquid pipe (43c) flows into the second connection pipe (46) in the fourth midway portion (Q4), and is depressurized in the heat source side expansion valve (36) to be first heat source side liquid. It flows into the middle part (5th middle part (Q5)) of the pipe (43a).
  • the target temperature setting unit (84) determines whether or not the use side unit (12) is in a dormant state.
  • the pressure of the refrigerant sucked into the first and second compressors (21a, 21b) decreases. And below the low pressure range.
  • the suction pressure rises and exceeds the low pressure range.
  • the low pressure range is set to the suction pressure when the lower limit value can be considered that the usage-side unit (12) has gone from the cooling state to the hibernation state, and the upper limit value is cooled from the hibernation state to the usage side unit (12). It is set to the suction pressure when it can be considered that the condition has been reached.
  • the target temperature setting unit (84) determines that the use side unit (12) is in the cooling state when the suction pressure exceeds the low pressure range, and the use side when the suction pressure is below the low pressure range. It is determined that the unit (12) is in a dormant state.
  • the target temperature setting unit (84) determines that the use side unit (12) has changed from the cooling state to the rest state, and the suction pressure increases and the low pressure When the range is exceeded, it is determined that the usage-side unit (12) has changed from the resting state to the cooling state. If it is determined that the usage-side unit (12) is in a dormant state, the process proceeds to step (ST23), and if not, the process proceeds to step (ST22).
  • Step (ST22)> When it is not determined in step (ST21) that the usage-side unit (12) is in the dormant state (that is, when the usage-side unit (12) is in the cooling state), the target temperature setting unit (84) performs the cooling operation. It is determined whether or not a predetermined time (T1) determined in advance has elapsed since the start of the process. The predetermined time (T1) is required from the start of the cooling operation until the internal temperature (Tr) decreases and the internal temperature (Tr) becomes a temperature in the vicinity of the internal set temperature (Tset). The time is set (for example, 24 hours). If it is determined that the predetermined time (T1) has elapsed, the process proceeds to step (ST23), and if not, the process proceeds to step (ST21).
  • the target temperature setting unit (84) has a period for reducing the internal temperature (Tr) from the start of the cooling operation (hereinafter referred to as “pull-down period (PD)”). It is determined whether or not it has elapsed. That is, in this example, the pull-down period (PD) includes the period from the start of the cooling operation to the time when the usage-side unit (12) enters the dormant state from the cooling state, and the predetermined time (T1) from the start of the cooling operation. ) Corresponds to the shorter of the period up to the point of time. And if it determines with the pull-down period (PD) having passed since the start of cooling operation, it will progress to step (ST23).
  • the target temperature setting unit (84) determines whether or not the use side unit (12) is in a cooling state.
  • the target temperature setting unit (84) determines that the use side unit (12) is in a cooling state when the suction pressure exceeds the low pressure range, and when the suction pressure is below the low pressure range, It determines with a use side unit (12) being a dormant state. That is, when the suction pressure decreases and falls below the low pressure range, the target temperature setting unit (84) determines that the use side unit (12) has changed from the cooling state to the rest state, and the suction pressure increases and the low pressure When the range is exceeded, it is determined that the usage-side unit (12) has changed from the resting state to the cooling state. If it is determined that the usage-side unit (12) is in the cooling state, the process proceeds to step (ST24).
  • the target temperature setting unit (84) starts measuring the elapsed time (Ton) from the time when it is determined in step (ST23) that the use side unit (12) is in the cooling state. That is, the target temperature setting unit (84) measures the length of a period during which the use side unit (12) is in a cooling state (hereinafter referred to as “cooling continuation period”).
  • the cooling continuation period is a period from the time when the user-side unit (12) changes from the dormant state to the cooled state to the next time point when the user side unit enters the dormant state from the cooling state or the end of the pull-down period (PD) This corresponds to the period from the time point to the time point when the next use side unit (12) enters the rest state from the cooling state.
  • the target temperature setting unit (84) determines whether or not the use side unit (12) is in a dormant state. If the user unit (12) is in the dormant state, the process proceeds to step (ST26), and if not, the process proceeds to step (ST29).
  • the target temperature setting unit (84) has a reference value (FQref) in which the frequency index value (FQi) in the cooling continuation period (that is, the period in which the use side unit (12) is in the cooling state) is determined in advance. It is determined whether it exceeds.
  • the frequency index value (FQi) is a value that depends on the operating frequency (FQ) of the first compressor (21a) during the cooling continuation period.
  • the frequency index value (FQi) may be a value corresponding to the average value (FQave) of the operating frequency (FQ) of the first compressor (21a) during the cooling continuation period.
  • the frequency index value (FQi) may be a value corresponding to the operating frequency (FQ) of the first compressor (21a) at the time when the usage-side unit (12) changes from the cooling state to the resting state.
  • the reference value (FQref) is a value that is a criterion for determining whether or not the operating frequency of the first compressor (21a) is relatively high.
  • the reference value (FQref) is set to a value corresponding to 60% of the maximum value (FQmax) of the operating frequency (FQ) of the first compressor (21a).
  • step (ST27) When it is determined that the frequency index value (FQi) exceeds the reference value (FQref), the process proceeds to step (ST27). Otherwise, the process proceeds to step (ST23).
  • the target temperature setting unit (84) determines whether or not the current target evaporation temperature (Te) is a predetermined upper limit temperature (Temax).
  • the upper limit temperature (Temax) is the target evaporation temperature (Te) when it can be assumed that the cooling capacity of the user unit (12) can be secured so that the inside of the cabinet is appropriately cooled in the cooling operation.
  • the upper limit temperature (Temax) is set to a temperature obtained by adding a predetermined temperature (for example, 3 ° C.) to the reference temperature (Teref). If it is determined that the current target evaporation temperature (Te) is the upper limit temperature (Temax), the process proceeds to step (ST23), and if not, the process proceeds to step (ST28).
  • the target temperature setting unit (84) corrects the target evaporation temperature (Te) so that the target evaporation temperature (Te) becomes high. Specifically, the target temperature setting unit (84) increases the target evaporation temperature (Te) by a predetermined temperature (for example, 1 ° C.). Next, the process proceeds to step (ST23).
  • Step (ST29)> when it is not determined in step (ST25) that the usage-side unit (12) is in a dormant state (that is, when the usage-side unit (12) is in a cooling state), the target temperature setting unit (84) It is determined whether the elapsed time (Ton) exceeds a predetermined duration threshold value (Tth).
  • the duration threshold (Tth) is the cooling duration when the cooling load in the warehouse is considered high after the elapse of the pull-down period (PD) (the period during which the usage unit (12) is in the cooling state) ) (For example, 1 hour). If the elapsed time (Ton) exceeds the duration threshold value (Tth), the process proceeds to step (ST30). Otherwise, the process proceeds to step (ST25).
  • the target temperature setting unit (84) determines whether or not the target evaporation temperature (Te) is the reference temperature (Teref). If it is determined that the target evaporation temperature (Te) is the reference temperature (Teref), the process proceeds to step (ST24), and if not, the process proceeds to step (ST31).
  • the target temperature setting unit (84) corrects the target evaporation temperature (Te) so that the target evaporation temperature (Te) decreases and approaches the reference temperature (Teref) or coincides with the reference temperature (Teref). . Specifically, the target temperature setting unit (84) decreases the target evaporation temperature (Te) by a predetermined temperature (for example, 1 ° C.). Next, the process proceeds to step (ST24). That is, the elapsed time (Ton) is set to zero, and the measurement of the elapsed time (Ton) is resumed.
  • a predetermined temperature for example, 1 ° C.
  • the pull-down period (PD) is a period from the start time of the cooling operation to the time point when the usage-side unit (12) enters the sleep state from the cooling state.
  • the pull-down period (PD) is a period from the start time of the cooling operation to the time point when the usage-side unit (12) enters the sleep state from the cooling state.
  • the use side unit (12) changes from the resting state to the cooling state. That is, the use side unit (12) performs a thermo-on operation. Thereby, the inside cooling is restarted and the inside temperature (Tr) gradually decreases.
  • thermo-off operation operation from the cooling state to the hibernation state
  • thermo-on operation operation from the hibernation state to the cooling state
  • the use side unit (12) when the cooling operation is started, the use side unit (12) is in a cooling state, and the internal temperature (Tr) gradually decreases.
  • the pull-down period (PD) elapses from the start of the cooling operation, the internal temperature (Tr) becomes a temperature in the vicinity of the internal set temperature (Tset), and the internal cooling load decreases. That is, in the period after the pull-down period (PD) has elapsed from the start of the cooling operation (in FIG. 7, the period from time (t1) to time (t4)), the internal temperature (Tr) is the internal set temperature (Tr). It can be considered that the period is stable in the vicinity of (Tset) and the cooling load in the storage is relatively low (hereinafter referred to as “internal storage low load period”).
  • FIG. 8 shows changes in the internal temperature (Tr) in the case where the target evaporation temperature (Te) is always the reference temperature (Teref) during the cooling operation period (that is, the comparative example of the refrigeration apparatus (10)). It shows the change in operating frequency (FQ).
  • FIG. 9 shows the change in the internal temperature (Tr) in the case where the target evaporation temperature (Te) is corrected according to the frequency index value (FQi) during the cooling operation period (that is, the refrigeration apparatus (10) according to this embodiment). And changes in operating frequency (FQ).
  • the cooling operation starts at time (t0), and the cooling operation ends at time (t1).
  • a change in temperature (Tr) and a change in operating frequency (FQ) are not shown.
  • the target evaporation temperature (Te) is a constant value (reference temperature (Teref)) in the period from time (t1) to time (t2).
  • the operating frequency (FQ) of the first compressor (21a) is close to the maximum value (FQmax) of the operating frequency (FQ) in the pull-down period (PD), and the elapse of the pull-down period (PD) Later it gradually decreases.
  • the target evaporation temperature (Te) is corrected in the period from time (t1) to time (t2).
  • the reference value (FQref) is set to a value corresponding to 60% of the maximum value (FQmax) of the operating frequency (FQ) of the first compressor (21a), and the target temperature setting unit ( 84) is configured to increase the target evaporation temperature (Te) by 1 ° C. when it is determined that the frequency index value (FQi) exceeds the reference value (FQref).
  • the target temperature setting unit (84) determines the frequency index value (FQi) (for example, from time (t1) to time (t1) to time (t1) It is determined that the average value (FQave) of the operating frequency (FQi) of the first compressor (21a) in the period up to t11) exceeds the reference value (FQref), and the target evaporation temperature (Teref) is increased by 1 ° C.
  • the target temperature setting unit (84) determines that the frequency index value (FQi) in the period from time (t11) to time (t12) exceeds the reference value (FQref). Increase target evaporation temperature (Te) by 1 ° C.
  • the target temperature setting unit (84) determines that the frequency index value (FQi) in the period from time (t12) to time (t13) exceeds the reference value (FQref). Increase target evaporation temperature (Te) by 1 ° C.
  • the compressor control unit (83) The operating frequency (FQ) of the first compressor (21a) is lowered so that the temperature of the refrigerant sucked into the first compressor (21a) increases. That is, by correcting the target evaporation temperature (Te) so that the target evaporation temperature (Te) becomes higher at the time (t11, t12, t13), the target evaporation temperature (Te) becomes a constant value. Further, it is possible to promote a decrease in the operating frequency (FQ) of the first compressor (21a) in the low load period in the refrigerator during the cooling operation (in FIG. 9, the period from time (t1) to time (t2)). .
  • the operating frequency (FQ) of the first compressor (21a) when the operating frequency (FQ) of the first compressor (21a) is reduced, the cooling capacity of the use side unit (12) is reduced, so the period during which the use side unit (12) is in the cooling state (cooling) (Continuation period) becomes longer, and the period during which the first compressor (21a) is set in the driving state also becomes longer.
  • the operation efficiency of the compressor tends to be higher when the compressor is driven at a low operating frequency for a long time than when the compressor is driven at a high operating frequency for a short time. Therefore, during the low load period during the cooling operation, the operating frequency (FQ) of the first compressor (21a) is decreased to improve the operating efficiency of the first compressor (21a) and to improve the refrigeration apparatus (10 ) Coefficient of performance (COP) can be improved.
  • the target temperature setting unit (84) sets the target evaporation temperature (Te) to the reference temperature (Teref) from the start of the cooling operation until the pull-down period (PD) elapses (step ( ST10)).
  • the target evaporation temperature (Te) to the reference temperature (Teref) from the start of the cooling operation until the pull-down period (PD) elapses (step ( ST10)).
  • the target temperature setting unit (84) sets the frequency index value (FQi) in the cooling continuation period (period in which the usage-side unit (12) is in the cooling state) after the elapse of the pull-down period (PD) to the reference value (
  • the target evaporation temperature (Te) is corrected so that the target evaporation temperature (Te) becomes higher than the reference temperature (Teref) (steps (ST21 to ST28)).
  • the target evaporation temperature (Te) is increased when the first compressor (21a) is driven at a relatively high operating frequency during the low load period in the refrigerator after the pull-down period (PD) has elapsed.
  • the coefficient of performance (COP) of the refrigeration apparatus (10) can be improved during the low load period in the refrigerator during the cooling operation.
  • the defrosting operation period (period during which the defrosting operation is performed) can be shortened, and the power consumption required for the defrosting operation can be reduced.
  • the target temperature setting unit (84) corrects the target evaporation temperature (Te) so that the target evaporation temperature (Te) does not exceed the upper limit temperature (Temax) (step (ST27)). If the target evaporation temperature (Te) becomes too high, the cooling capacity of the use side unit (12) may be insufficient, and the inside of the warehouse may not be properly cooled. Therefore, the target evaporation temperature (Te) can be prevented from becoming too high by correcting the target evaporation temperature (Te) so that the target evaporation temperature (Te) does not exceed the upper limit temperature (Temax). Insufficient cooling capacity of the user unit (12) due to an increase in the evaporation temperature (Te) can be prevented. Thereby, the inside of a store
  • the target temperature setting unit (84) is configured to provide a cooling continuation period (a period during which the use side unit (12) is in a cooling state) when the target evaporation temperature (Te) is higher than the reference temperature (Teref). ) Exceeds the duration threshold (Tth), the target evaporation temperature (Te) decreases so that the target evaporation temperature (Te) approaches or coincides with the reference temperature (Teref). Is corrected (steps (ST29 to ST31)). In addition, in the low load period in the warehouse after the elapse of the pull-down period (PD), heat outside the warehouse may enter the warehouse due to opening and closing of the door, and the cooling load in the warehouse may increase.
  • a cooling continuation period a period during which the use side unit (12) is in a cooling state
  • the target temperature setting unit (84) sets the target evaporation temperature (Te) to the reference temperature (Teref) after the end of the cooling operation and before the start of the defrosting operation (step (ST13)).
  • the heat radiation capacity of the usage side unit (12) (specifically, the heat radiation capacity of the usage side heat exchanger (51)) can be ensured in the defrosting operation, so the usage side heat exchange in the defrosting operation.
  • the defrosting of the vessel (51) can be performed appropriately.
  • the pull-down period (PD) is the period from the start of the cooling operation to the time when the user unit (12) goes from the cooling state to the dormant state, and the predetermined time (T1) has elapsed from the start of the cooling operation. This corresponds to the shorter period of the period up to the time point.
  • the internal temperature (Tr) may be regarded as being in the vicinity of the internal set temperature (Tset). it can.
  • the predetermined time (T1)) even if a sufficient time (that is, the predetermined time (T1)) has elapsed after the start of the cooling operation, it is considered that the internal temperature (Tr) is close to the internal set temperature (Tset). Can do. Therefore, the period from the start of the cooling operation to the time when the user-side unit (12) enters the dormant state from the cooling state and the period from the start of the cooling operation to the time when the predetermined time (T1) has elapsed are short. By setting this period as the pull-down period (PD), the internal temperature (Tr) is lowered in the pull-down period (DP) to bring the internal temperature (Tr) to a temperature close to the internal set temperature (Tset). be able to.
  • a sufficient time that is, the predetermined time (T1)
  • Tset internal set temperature
  • the period from the start of the cooling operation to the time when the user-side unit (12) enters the dormant state from the cooling state to the time when the predetermined time (T1) has elapsed from the start of the cooling operation is set as the pull-down period (PD).
  • the pull-down period (PD) indicates that the user unit (12) has changed from the cooling state to the dormant state from the start of the cooling operation. It may be a period until a certain point. That is, step (ST22) shown in FIG. 5 may be omitted.
  • the pull-down period (PD) may be a period from the start of the cooling operation to the time when a predetermined time (T1) has elapsed. That is, step (ST21) shown in FIG. 5 may be omitted.
  • the above-described refrigeration apparatus is useful as a refrigeration apparatus that cools the inside of the refrigerator.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Devices That Are Associated With Refrigeration Equipment (AREA)
  • Compression-Type Refrigeration Machines With Reversible Cycles (AREA)
PCT/JP2016/003624 2015-08-07 2016-08-05 冷凍装置 WO2017026115A1 (ja)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP16834816.7A EP3333503B1 (de) 2015-08-07 2016-08-05 Kühlvorrichtung
CN201680046138.2A CN107850347B (zh) 2015-08-07 2016-08-05 制冷装置

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2015157590A JP6048549B1 (ja) 2015-08-07 2015-08-07 冷凍装置
JP2015-157590 2015-08-07

Publications (1)

Publication Number Publication Date
WO2017026115A1 true WO2017026115A1 (ja) 2017-02-16

Family

ID=57572385

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2016/003624 WO2017026115A1 (ja) 2015-08-07 2016-08-05 冷凍装置

Country Status (4)

Country Link
EP (1) EP3333503B1 (de)
JP (1) JP6048549B1 (de)
CN (1) CN107850347B (de)
WO (1) WO2017026115A1 (de)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6948796B2 (ja) * 2017-01-24 2021-10-13 三菱重工サーマルシステムズ株式会社 冷媒回路システム及び制御方法
WO2021229770A1 (ja) * 2020-05-14 2021-11-18 三菱電機株式会社 冷凍装置
CN112963888B (zh) * 2021-01-28 2022-12-23 浙江中广电器集团股份有限公司 一种具有无水地暖功能多联机的压缩机冷油启动方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11304344A (ja) * 1998-04-27 1999-11-05 Toshiba Corp 冷蔵庫
JP2007225155A (ja) * 2006-02-21 2007-09-06 Mitsubishi Electric Corp 除霜運転制御装置および除霜運転制御方法
JP2008070015A (ja) * 2006-09-13 2008-03-27 Toshiba Corp 冷蔵庫
JP2010175203A (ja) * 2009-01-30 2010-08-12 Hitachi Appliances Inc 冷凍装置
WO2014103028A1 (ja) * 2012-12-28 2014-07-03 三菱電機株式会社 空気調和装置

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2005090808A (ja) * 2003-09-16 2005-04-07 Matsushita Electric Ind Co Ltd 冷蔵庫
JP2009115359A (ja) * 2007-11-05 2009-05-28 Daikin Ind Ltd 空調制御装置、空気調和装置および空調制御方法
US8015833B2 (en) * 2009-05-28 2011-09-13 Ford Global Technologies, Llc Automotive climate system and method of controlling same
JP4993014B2 (ja) * 2010-09-30 2012-08-08 ダイキン工業株式会社 コントローラおよび空調処理システム
JP5370560B2 (ja) * 2011-09-30 2013-12-18 ダイキン工業株式会社 冷媒サイクルシステム
KR20130134349A (ko) * 2012-05-30 2013-12-10 삼성전자주식회사 멀티형 공기조화기 및 그 냉난방제어방법
CN104755849B (zh) * 2012-10-18 2017-04-05 大金工业株式会社 空调装置
US9696078B2 (en) * 2013-11-20 2017-07-04 Mitsubishi Electric Corporation Refrigeration cycle apparatus
CN104019528B (zh) * 2014-06-26 2016-06-22 东元总合科技（杭州）有限公司 变频空调高效节能运转控制算法

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11304344A (ja) * 1998-04-27 1999-11-05 Toshiba Corp 冷蔵庫
JP2007225155A (ja) * 2006-02-21 2007-09-06 Mitsubishi Electric Corp 除霜運転制御装置および除霜運転制御方法
JP2008070015A (ja) * 2006-09-13 2008-03-27 Toshiba Corp 冷蔵庫
JP2010175203A (ja) * 2009-01-30 2010-08-12 Hitachi Appliances Inc 冷凍装置
WO2014103028A1 (ja) * 2012-12-28 2014-07-03 三菱電機株式会社 空気調和装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3333503A4 *

Also Published As

Publication number Publication date
EP3333503B1 (de) 2024-05-15
EP3333503A4 (de) 2019-04-03
CN107850347A (zh) 2018-03-27
JP2017036872A (ja) 2017-02-16
JP6048549B1 (ja) 2016-12-21
CN107850347B (zh) 2020-07-10
EP3333503A1 (de) 2018-06-13

Similar Documents

Publication Publication Date Title
US10077924B2 (en) Binary refrigeration apparatus
US10001310B2 (en) Binary refrigeration apparatus
TWI522585B (zh) Refrigeration unit and freezer unit
JP2008096033A (ja) 冷凍装置
JP4760974B2 (ja) 冷凍装置
JP5971377B1 (ja) 冷凍装置
JP4479828B2 (ja) 冷凍装置
JP2013178046A (ja) 空気調和装置
WO2017026115A1 (ja) 冷凍装置
JP6142896B2 (ja) 冷凍装置
JP2011007482A (ja) 空気調和装置
JP2009264612A (ja) 冷凍装置
JP2018173195A (ja) 冷凍装置
JP4120471B2 (ja) 冷凍装置
JP2018096632A (ja) 冷媒回路システム、制御装置及び制御方法
WO2020179005A1 (ja) 冷凍サイクル装置
JP2009236346A (ja) 冷凍装置
EP2781863A2 (de) Verfahren zur Steuerung eines Kühlschranks
KR102494567B1 (ko) 냉장고 및 그 제어방법
JP2014070829A (ja) 冷凍装置
JP3780955B2 (ja) 冷凍装置
JP2011237054A (ja) 冷凍装置
JP2016161195A (ja) 冷凍装置
JP2014005949A (ja) 冷凍装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16834816

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2016834816

Country of ref document: EP