EP4006443A1 - Refrigeration apparatus - Google Patents
Refrigeration apparatus Download PDFInfo
- Publication number
- EP4006443A1 EP4006443A1 EP21209825.5A EP21209825A EP4006443A1 EP 4006443 A1 EP4006443 A1 EP 4006443A1 EP 21209825 A EP21209825 A EP 21209825A EP 4006443 A1 EP4006443 A1 EP 4006443A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- refrigerant
- flow channel
- compression mechanism
- gas
- refrigeration apparatus
- Prior art date
- Legal status (The legal status 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 status listed.)
- Withdrawn
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
- F25B1/00—Compression machines, plants or systems with non-reversible cycle
- F25B1/10—Compression machines, plants or systems with non-reversible cycle with multi-stage compression
-
- 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
- F25B41/00—Fluid-circulation 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
- 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
-
- 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
- F25B9/08—Compression machines, plants or systems, in which the refrigerant is air or other gas of low boiling point using ejectors
-
- 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
- F25B2341/00—Details of ejectors not being used as compression device; Details of flow restrictors or expansion valves
- F25B2341/001—Ejectors not being used as compression device
- F25B2341/0012—Ejectors with the cooled primary flow at high 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
- 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
- F25B2400/05—Compression system with heat exchange between particular parts of the system
-
- 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
- F25B2400/072—Intercoolers therefor
-
- 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
-
- 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
- F25B2400/13—Economisers
-
- 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
- F25B2400/23—Separators
-
- 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
- F25B2700/19—Pressures
- F25B2700/195—Pressures of the condenser
-
- 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
- F25B2700/2106—Temperatures of fresh outdoor air
Definitions
- the present disclosure relates to a refrigeration apparatus in which a refrigerant containing carbon dioxide circulates.
- a refrigeration apparatus includes a refrigeration cycle formed from a compression section, a gas cooler, a throttle section, an evaporator, and the like.
- a refrigerant compressed in the compression section radiates heat in the gas cooler, and is then decompressed in the throttle section and evaporates in the evaporator. As the refrigerant evaporates, the surrounding air is cooled.
- An object of the present disclosure is to improve the performance of a refrigeration apparatus which uses a refrigerant containing carbon dioxide and utilizes an ejector.
- a refrigeration apparatus includes a main compression mechanism, a gas cooler, a main throttle mechanism, and an evaporator, and allows circulation of a refrigerant containing carbon dioxide.
- the refrigeration apparatus includes a split heat exchanger including a first flow channel and a second flow channel, in which the first flow channel is disposed at a site downstream of the gas cooler and upstream of the main throttle mechanism, and part of a refrigerant flowing out of the first flow channel flows into the second flow channel; an auxiliary throttle mechanism that throttles a refrigerant that is to flow into the second flow channel; and an ejector including a nozzle and a suction part, in which the nozzle is disposed at a site downstream of the main compression mechanism and upstream of the first flow channel, and the suction part sucks in a refrigerant flowing out of the second flow channel.
- the present disclosure is capable of improving the performance of a refrigeration apparatus which uses a refrigerant containing carbon dioxide and uses an ejector.
- FIG. 1 illustrates a refrigerant circuit of refrigeration apparatus 1 according to Embodiment 1.
- Refrigeration apparatus 1 includes refrigerator unit 2 installed in, for example, an indoor machine room or an outdoor environment, and load device 3, for example, a showcase installed in a supermarket or the like.
- Refrigerator unit 2 and load device 3 are connected with each other by refrigerant pipe (liquid pipe) 31 and refrigerant pipe 32 via unit outlet 2 out and unit inlet 2in to form predetermined refrigerant circuit 4.
- Load device 3 may be a cooling coil of a food warehouse or the like, or a cooling device for cooling a refrigerant such as water.
- Carbon dioxide (R744) whose pressure on the high pressure side may become equal to or higher than the critical pressure (supercritical), circulates as a refrigerant in refrigerant circuit 4.
- the refrigerant may consist only of carbon dioxide, or may be a mixed refrigerant containing carbon dioxide and other substances.
- the mixed refrigerant may contain carbon dioxide and, for example, one or more of R32, R41, R134a, R125, R152a, propane and dimethyl ether. Each arrow shown in FIG. 1 indicates the flow of a refrigerant.
- the lubricating oil that circulates in refrigerant circuit 4 together with the refrigerant is, for example, mineral oil, alkylbenzene oil, ether oil, ester oil, or PAG (polyalkyl glycol).
- Refrigerant circuit 4 includes main compression mechanism 11, gas cooler 12, ejector 13, split heat exchanger 14, and auxiliary throttle mechanism 15 in refrigerator unit 2.
- Refrigerant circuit 4 includes main throttle mechanism 16 and evaporator 17 in load device 3.
- Main compression mechanism 11 which is a frequency-variable compressor, has one or more compression mechanism parts, sucks a refrigerant in a gas-phase (i.e., gas-phase refrigerant), and discharges the refrigerant having a high temperature and high pressure.
- gas-phase i.e., gas-phase refrigerant
- the refrigerant discharged from main compression mechanism 11 passes through pipe 21 to flow into gas cooler 12.
- Gas cooler 12 lowers the temperature of the refrigerant by exchanging heat between the refrigerant and the outside air supplied by a blower for the gas cooler (not illustrated). Alternatively, gas cooler 12 may exchange heat between the refrigerant and water supplied by a water pump for the gas cooler.
- Nozzle 131 is configured in such a way that the opening degree thereof can be adjusted.
- the opening degree of nozzle 131 increases, the flow velocity of the refrigerant, which flows in from nozzle 131 and passes through ejector 13, decreases, and when the opening degree decreases, the flow velocity of the refrigerant increases.
- the refrigerant flowing into nozzle 131 expands while mixing with a gas-phase refrigerant sucked in from suction part 132 (which will be described below) and flows out of ejector 13 in a gas-liquid mixed state.
- suction part 132 which will be described below
- the static pressure in ejector 13 decreases, so that the suction pressure in suction part 132 decreases (suction becomes easier).
- the static pressure in ejector 13 increases, so that the suction pressure in suction part 132 increases (suction becomes more difficult).
- the refrigerant flowing out of ejector 13 passes through pipe 23 to flow into first flow channel 141 of split heat exchanger 14.
- the refrigerant flowing into first flow channel 141 flows out of first flow channel 141 with the temperature of the refrigerant lowered by exchanging heat with a refrigerant that flows through second flow channel 142 (which will be described below).
- Main throttle mechanism 16 is, for example, an electric expansion valve whose opening degree can be adjusted.
- auxiliary throttle mechanism 15 is, for example, an electric expansion valve whose opening degree can be adjusted.
- Auxiliary throttle mechanism 15 expands and vaporizes the refrigerant flowing into auxiliary throttle mechanism 15. The temperature of the refrigerant is lowered during the procedure.
- auxiliary throttle mechanism 15 The refrigerant flowing out of auxiliary throttle mechanism 15 is in a gas-liquid mixed state, and passes through pipe 27 to flow into second flow channel 142 of split heat exchanger 14.
- the refrigerant flowing into second flow channel 142 exchanges heat with a refrigerant passing through first flow channel 141 to lower the temperature of the refrigerant passing through first flow channel 141 as described above, and then flows out of second flow channel 142.
- the refrigerant flowing out of second flow channel 142 passes through pipe 28 and is sucked into suction part 132 of ejector 13.
- the refrigerant sucked into ejector 13 from suction part 132 mixes with a refrigerant sucked from nozzle 131.
- main throttle mechanism 16 which is, for example, an electric expansion valve.
- the refrigerant flowing out of main throttle mechanism 16 flows into evaporator 17 via refrigerant pipe 33, and is completely evaporated in evaporator 17.
- the refrigerant flowing through evaporator 17 exchanges heat with a fluid in load device 3, for example, air, and cools the air.
- the fluid in load device 3 may be another refrigerant (for example, water), which is to be cooled by the refrigerant circulating in refrigerant circuit 4.
- the refrigerant flowing out of evaporator 17 passes through refrigerant pipe 32, unit inlet 2in and pipe 29, and is sucked into main compression mechanism 11.
- Refrigerator unit 2 includes control device 50 that controls the entire refrigeration apparatus 1.
- Low pressure sensor 51 (herein also referred to as “third pressure sensor”), which detects the pressure (low pressure) of the refrigerant to be sucked into main compression mechanism 11, is attached at a site downstream of main throttle mechanism 16 and upstream of main compression mechanism 11, for example, at pipe 29. A value detected by low pressure sensor 51 is transmitted to control device 50.
- the value detected by low pressure sensor 51 indicates the evaporation pressure of a refrigerant in evaporator 17, that is, the temperature of the refrigerant in evaporator 17.
- Control device 50 can adjust the temperature of the refrigerant in evaporator 17 and thus the temperature of a fluid in load device 3 by adjusting the operating frequency of main compression mechanism 11 based on the detection result from low pressure sensor 51. In other words, control device 50 can cause main compression mechanism 11 to perform an operation according to the refrigeration capacity required in load device 3.
- the carbon dioxide-containing refrigerant can generate a fluid of desired temperature and quantity in evaporator 17 by repeating the above described cycle.
- the refrigeration apparatus 1 includes ejector 13, split heat exchanger 14, and auxiliary throttle mechanism 15 as described above.
- Ejector 13 can expand a refrigerant that has become in a high pressure state without requiring power.
- Split heat exchanger 14 and auxiliary throttle mechanism 15 can lower the temperature of a refrigerant that has flowed out of ejector 13 before the refrigerant flows into main throttle mechanism 16.
- Main throttle mechanism 16 can expand the refrigerant having passed through split heat exchanger 14 to lower its temperature.
- refrigeration apparatus 1 is capable of adjusting the pressure on the high-pressure side (discharge side of main compression mechanism 11) while obtaining a desired refrigeration capacity in load device 3 by virtue of the presence of ejector 13, split heat exchanger 14, and auxiliary throttle mechanism 15 in the refrigeration apparatus. That is, refrigeration apparatus 1 can appropriately operate main compression mechanism 11 according to the temperature of the outside air or water supplied to gas cooler 12.
- ejector 13 is disposed between gas cooler 12 and first flow channel 141 of split heat exchanger 14.
- ejector 13 may be disposed at any site downstream of main compression mechanism 11 and upstream of first flow channel 141.
- ejector 13 may be disposed at a site downstream of main compression mechanism 11 and upstream of gas cooler 12. This disposition allows for efficient generation of cooled fluid (e.g., air or water) of desired temperature and quantity, in addition to the effects described above.
- cooled fluid e.g., air or water
- FIG. 2 illustrates a refrigerant circuit of refrigeration apparatus 1 according to Embodiment 2.
- the description of matters common to Embodiment 1 may be omitted. Conversely, the description for the present embodiment may apply to Embodiment 1.
- Refrigeration apparatus 1 includes gas-liquid separator 18, auxiliary compression mechanism 19, and a transfer pressure sensor 52 (herein also referred to as "first pressure sensor").
- first pressure sensor a transfer pressure sensor 52
- pipe 23 connecting ejector 13 with first flow channel 141 of split heat exchanger 14 is divided into pipe 231 on the upstream side and pipe 232 on the downstream side, and gas-liquid separator 18 is disposed between these pipes.
- Gas-liquid separator 18 is a tank capable of storing a refrigerant.
- a refrigerant in a gas-liquid mixed state flows into gas-liquid separator 18 via the inlet connected to pipe 231.
- the refrigerant that has flowed into gas-liquid separator 18 is separated into a gas-phase refrigerant and a liquid-phase refrigerant.
- the liquid-phase refrigerant separated in gas-liquid separator 18 flows out from the liquid-phase refrigerant outlet of gas-liquid separator 18 connected to pipe 232 and flows into first flow channel 141 of split heat exchanger 14.
- the gas-phase refrigerant separated in gas-liquid separator 18 flows out from the gas-phase refrigerant outlet of gas-liquid separator 18 connected to pipe 41.
- the gas-phase refrigerant flowing out of the gas-phase refrigerant outlet passes through pipe 41 and is sucked into auxiliary compression mechanism 19.
- Transfer pressure sensor 52 is disposed at pipe 41. Transfer pressure sensor 52 detects the pressure of a refrigerant that is to flow into main throttle mechanism 16. A value detected by transfer pressure sensor 52 is transmitted to control device 50.
- Transfer pressure sensor 52 may be disposed at any site other than pipe 41 when the transfer pressure sensor 52 can detect the pressure of the refrigerant that is to flow into main throttle mechanism 16. Transfer pressure sensor 52 may be disposed, for example, at pipe 231, gas-liquid separator 18, pipe 232, first flow channel 141, pipe 24, branch part 25, branch pipe 26, or refrigerant pipe 31.
- Auxiliary compression mechanism 19 is, for example, a compressor including an airtight container, an electric element that serves as a drive element housed in internal space of the airtight container, and a rotary compression element driven by a rotating shaft of the electric element.
- a refrigerant compressed by auxiliary compression mechanism 19 is discharged to merging pipe 42.
- Merging pipe 42 is connected to pipe 21 at merging part 43 that is provided between the ends of pipe 21, downstream of main compression mechanism 11 and upstream of gas cooler 12.
- the refrigerant discharged to merging pipe 42 from auxiliary compression mechanism 19 passes through merging pipe 42 and merging part 43 to join a refrigerant in pipe 21 discharged from main compression mechanism 11.
- Refrigeration apparatus 1 includes high pressure sensor 53 (herein also referred to as “second pressure sensor”) and outside air temperature sensor 54 (herein also referred to as “first temperature sensor”). Values detected by those sensors are transmitted to control device 50.
- High pressure sensor 53 detects the pressure (high pressure) of a refrigerant discharged from main compression mechanism 11, and may be disposed anywhere, in so far as the high pressure sensor can detect this pressure. In the present embodiment, high pressure sensor 53 is disposed at pipe 22, but may be disposed at pipe 21 or at gas cooler 12.
- Outside air temperature sensor 54 detects the outside air temperature, that is, the temperature of a fluid, for cooling the refrigerant, in gas cooler 12. Outside air temperature sensor 54 is disposed, for example, in the vicinity of gas cooler 12. Gas cooler 12 is not necessarily limited to a cooler that cools a refrigerant with outside air, and may be, for example, a cooler that cools the refrigerant with water. In this case, the first temperature sensor is a water temperature sensor in place of outside air temperature sensor 54.
- Refrigeration apparatus 1 includes transfer temperature sensor 55 (herein also referred to as “second temperature sensor”) and second flow channel inlet temperature sensor 56 (herein also referred to as “third temperature sensor”). Values detected by those sensors are transmitted to control device 50.
- second temperature sensor transfer temperature sensor 55
- second flow channel inlet temperature sensor 56 herein also referred to as “third temperature sensor”
- Transfer temperature sensor 55 detects the temperature of a refrigerant to be supplied to main throttle mechanism 16, and may be disposed anywhere, in so far as the transfer temperature sensor can detect this temperature. In the present embodiment, transfer temperature sensor 55 is disposed at pipe 24, but may be disposed at branch part 25 or branch pipe 26, or may be disposed at refrigerant pipe 31.
- Second flow channel inlet temperature sensor 56 detects the temperature of a refrigerant that is to flow into second flow channel 142 of split heat exchanger 14, and is disposed at pipe 27.
- a refrigerant circulates as follows.
- Main compression mechanism 11 sucks a refrigerant in a gas-phase state and discharges the refrigerant in a high pressure state.
- the refrigerant discharged from main compression mechanism 11 passes through pipe 21 to flow into gas cooler 12.
- the refrigerant whose temperature is lowered in the gas cooler passes through pipe 22 to flow into nozzle 131 of ejector 13.
- the refrigerant flowing into nozzle 131 expands while mixing with a gas-phase refrigerant sucked in from suction part 132 and flows out of ejector 13 in a gas-liquid mixed state.
- the refrigerant flowing out of ejector 13 passes through pipe 231 to flow into gas-liquid separator 18.
- gas-liquid separator 18 the refrigerant is separated into a gas-phase refrigerant and a liquid-phase refrigerant.
- the liquid-phase refrigerant from the inside of gas-liquid separator 18 passes through pipe 232 and flows into first flow channel 141 of split heat exchanger 14.
- first flow channel 141 the liquid-phase refrigerant exchanges heat with a refrigerant passing through second flow channel 142 of split heat exchanger 14 and is cooled.
- the liquid-phase refrigerant flowing out of first flow channel 141 passes through pipe 24, branch part 25, unit outlet 2 out , and refrigerant pipe 31 to flow into main throttle mechanism 16.
- the refrigerant that flows into main throttle mechanism 16 is throttled and expanded by main throttle mechanism 16.
- the refrigerant flowing out of main throttle mechanism 16 flows into evaporator 17 via refrigerant pipe 33, and is evaporated. At this time, the refrigerant exchanges heat with the surrounding air to generate cold air.
- the fluid to be subjected to the heat exchange in evaporator 17 does not have to be air.
- load device 3 may cool water to generate cold water.
- the gas-phase refrigerant flowing out of evaporator 17 passes through refrigerant pipe 32, unit inlet 2in and pipe 29, and is sucked into main compression mechanism 11 again.
- the liquid-phase refrigerant which is branched off at branch part 25 and flows into branch pipe 26, flows into auxiliary throttle mechanism 15.
- the refrigerant that flows into auxiliary throttle mechanism 15 is throttled and expanded by auxiliary throttle mechanism 15.
- the refrigerant flowing out of auxiliary throttle mechanism 15 flows into second flow channel 142 of split heat exchanger 14 via pipe 27, and is evaporated.
- the refrigerant flowing into second flow channel 142 exchanges heat with a refrigerant passing through first flow channel 141 to lower the temperature of the refrigerant passing through first flow channel 141.
- the refrigerant flowing out of second flow channel 142 passes through pipe 28 and is sucked from suction part 132 of ejector 13.
- the refrigerant sucked from suction part 132 mixes with a refrigerant flowing into nozzle 131 in ejector 13, and then flows out of ejector 13 and flows into gas-liquid separator 18 again.
- the gas-phase refrigerant from the inside of gas-liquid separator 18 passes through pipe 41 and is sucked into auxiliary compression mechanism 19.
- the refrigerant sucked into auxiliary compression mechanism 19 is compressed by auxiliary compression mechanism 19 until the refrigerant has a pressure equal to the pressure of a refrigerant at the outlet of main compression mechanism 11, and then discharged to merging pipe 42.
- the refrigerant discharged from auxiliary compression mechanism 19 to merging pipe 42 joins the refrigerant in pipe 21 discharged from main compression mechanism 11 via merging part 43.
- auxiliary compression mechanism 19 can reduce the pressure in gas-liquid separator 18, that is, can lower the temperature of a refrigerant in gas-liquid separator 18. This configuration can lower the temperature of a refrigerant supplied to evaporator 17.
- auxiliary compression mechanism 19 sucks a gas-phase refrigerant from the inside of gas-liquid separator 18 (the refrigerant whose pressure is relatively high), but not a gas-phase refrigerant flowing out of second flow channel 142 (the refrigerant whose pressure is reduced after passing through auxiliary throttle mechanism 15).
- the gas-phase refrigerant flowing out of second flow channel 142 is sucked by ejector 13. Therefore, the pressure of the refrigerant passing through second flow channel 142 can be reduced by the action of ejector 13 without increasing the power (that is, the input power) of auxiliary compression mechanism 19, and further, the temperature of the refrigerant passing through second flow channel 142 can be lowered.
- Lowering the temperature of the refrigerant passing through second flow channel 142 can lower the temperature of a refrigerant flowing out of first flow channel 141.
- This configuration can lower the temperature of a refrigerant supplied to evaporator 17.
- the refrigeration capacity of refrigeration apparatus 1 thus can be increased, and also the refrigeration efficiency can be improved.
- control device 50 adjusts the operating frequency of auxiliary compression mechanism 19 based on the detection result from transfer pressure sensor 52. Accordingly, the transfer pressure, that is, the pressure of a refrigerant supplied to main throttle mechanism 16 can be set to a predetermined value. It becomes thus easier to set the pressure of a refrigerant after the refrigerant is throttled by main throttle mechanism 16 to a predetermined value, and as a result, setting the pressure and temperature of a refrigerant flowing into evaporator 17 to predetermined values becomes easier. This configuration allows evaporator 17 to stably generate cold air of desired temperature and quantity.
- control device 50 adjusts the opening degree of nozzle 131 of ejector 13 based on the detection results from high pressure sensor 53 and from outside air temperature sensor 54 in the present embodiment. That is, control device 50 adjusts the discharge pressure of main compression mechanism 11, namely the pressure of a refrigerant in gas cooler 12, based on the temperature of a fluid for exchanging heat with the refrigerant in gas cooler 12.
- control device 50 can increase the pressure of a refrigerant in gas cooler 12 by reducing the opening degree of nozzle 131 in such a way that the value detected by high pressure sensor 53 becomes a target value.
- the flow velocity of the refrigerant in ejector 13 then increases, and the pressure of a refrigerant sucked from suction part 132 decreases.
- the temperature of the refrigerant supplied from split heat exchanger 14 to main throttle mechanism 16 decreases.
- control device 50 can reduce the pressure of a refrigerant in gas cooler 12 by increasing the opening degree of nozzle 131 in such a way that the value detected by high pressure sensor 53 becomes a target value.
- the flow velocity of the refrigerant in ejector 13 then decreases, and the pressure of a refrigerant sucked from suction part 132 increases.
- the temperature of a refrigerant supplied from split heat exchanger 14 to main throttle mechanism 16 increases.
- the control as described above can optimize the operating state of main compression mechanism 11, namely the power consumption of main compression mechanism 11, thereby improving energy conservation of refrigeration apparatus 1.
- control device 50 adjusts the opening degree of auxiliary throttle mechanism 15 based on the detection results from transfer temperature sensor 55 and from second flow channel inlet temperature sensor 56 in the present embodiment.
- auxiliary throttle mechanism 15 is adjusted in such a way that the value detected by transfer temperature sensor 55 approaches the value detected by second flow channel inlet temperature sensor 56.
- the control as described above can lower the temperature of a refrigerant supplied to evaporator 17 via main throttle mechanism 16.
- the refrigeration capacity of refrigeration apparatus 1 thus can be increased, and also the refrigeration efficiency can be improved.
- the control to adjust the opening degree of auxiliary throttle mechanism 15 based on the detection results from transfer temperature sensor 55 and from second flow channel inlet temperature sensor 56 is particularly effective when the opening degree of nozzle 131 of ejector 13 changes due to changes in the outside temperature and/or the like.
- the temperature of a refrigerant flowing into second flow channel 142 changes.
- the temperature of a refrigerant flowing out of first flow channel 141 and supplied to main throttle mechanism 16 may change.
- adjusting the opening degree of auxiliary throttle mechanism 15 based on the detection results from transfer temperature sensor 55 and from second flow channel inlet temperature sensor 56 can still maintain the temperature of the refrigerant supplied to main throttle mechanism 16 at a desired value.
- FIG. 3 illustrates a refrigerant circuit of refrigeration apparatus 1 according to Embodiment 3.
- the description of matters common to Embodiments 1 and 2 may be omitted. Conversely, the description for the present embodiment may apply to Embodiments 1 and 2.
- main compression mechanism 11 includes low-stage compression mechanism 111 and high-stage compression mechanism 112.
- Refrigeration apparatus 1 according to the present embodiment also include intercooler 121.
- Intercooler 121 is disposed between low-stage compression mechanism 111 and high-stage compression mechanism 112 in refrigerant circuit 4 via pipe 44 on the upstream side and pipe 45 on the downstream side.
- Main compression mechanism 11 is, for example, an internal intermediate-pressure two-stage compression type rotary compressor.
- Main compression mechanism 11 includes an airtight container and a rotary compression mechanism part.
- the rotary compression mechanism part includes an electric element that serves as a drive element housed in an upper portion of the internal space of the airtight container, and a first rotary compression element (low-stage compression mechanism 111) and a second rotary compression element (high-stage compression mechanism 112) disposed below the electric element.
- Main compression mechanism 11 is a two-stage compressor including the first rotary compression element and the second rotary compression element driven by the same rotary shaft (rotary shaft of the electric element).
- Low-stage compression mechanism 111 and high-stage compression mechanism 112 may be single-stage compression compressors that are independent of each other.
- Low-stage compression mechanism 111 compresses a refrigerant having a low pressure sucked into main compression mechanism 11 from the low-pressure side of refrigerant circuit 4 via pipe 29, increases the pressure of the refrigerant to an intermediate pressure, and discharges the refrigerant.
- High-stage compression mechanism 112 sucks in the refrigerant having an intermediate pressure discharged from low-stage compression mechanism 111, compresses the refrigerant until the refrigerant has a high pressure, and discharges the refrigerant to the high-pressure side of refrigerant circuit 4.
- Main compression mechanism 11 is a frequency-variable compressor.
- Control device 50 controls the rotation speeds of low-stage compression mechanism 111 and high-stage compression mechanism 112 by changing the operating frequency of the electric element.
- a low-stage side suction port communicating with low-stage compression mechanism 111
- a low-stage side discharge port communicating with the inside of the airtight container
- a high-stage side suction port communicating with high-stage compression mechanism 112
- a high-stage side discharge port communicating with high-stage compression mechanism 112
- One end of pipe 29 is connected to the low-stage side suction port of main compression mechanism 11, and the other end of pipe 29 is connected to refrigerant pipe 32 at unit inlet 2in.
- a refrigerant gas having a low pressure sucked into the low-pressure part of low-stage compression mechanism 111 from the low-stage side suction port is subjected to the first-stage compression by low-stage compression mechanism 111 to have an intermediate pressure, and discharged into the airtight container. As a result, the pressure inside the airtight container becomes an intermediate pressure.
- pipe 44 is connected to the low-stage side discharge port of main compression mechanism 11 from which the refrigerant gas having the intermediate pressure in the airtight container is discharged, and the other end of pipe 44 is connected to the inlet of intercooler 121.
- Intercooler 121 cools the intermediate pressure refrigerant gas discharged from low-stage compression mechanism 111.
- One end of pipe 45 is connected to the outlet of intercooler 121.
- the other end of pipe 45 is connected to the high-stage side suction port of main compression mechanism 11.
- the intermediate pressure refrigerant gas sucked into high-stage compression mechanism 112 from the high-stage side suction port of main compression mechanism 11 is subjected to the second-stage compression by high-stage compression mechanism 112 to become a refrigerant gas having high temperature and high pressure.
- pipe 21 One end of pipe 21 is connected to the high-stage side discharge port provided on the high-pressure chamber side of high-stage compression mechanism 112 in main compression mechanism 11, and the other end of pipe 21 is connected to the inlet of gas cooler 12.
- An oil separator (not illustrated) may be provided at pipe 21 between the ends of the pipe. The oil separated from the refrigerant by the oil separator is returned to the airtight container of main compression mechanism 11 and the airtight container of auxiliary compression mechanism 19.
- Gas cooler 12 cools the refrigerant having a high pressure discharged from main compression mechanism 11.
- a blower for the gas cooler (not illustrated) for air-cooling gas cooler 12 is provided in the vicinity of gas cooler 12.
- gas cooler 12 is provided in parallel with above described intercooler 121, and the coolers are provided in the same air passage.
- Gas cooler 12 and intercooler 121 may be water-cooled.
- a water pump for the gas cooler is provided in place of the blower for the gas cooler, and water is input to the gas cooler and the intercooler in parallel.
- pipe 22 One end of pipe 22 is connected to the outlet of gas cooler 12, and the other end of pipe 22 is connected to the inlet of nozzle 131 of ejector 13.
- main compression mechanism 11 includes low-stage compression mechanism 111 and high-stage compression mechanism 112.
- Intercooler 121 is disposed between low-stage compression mechanism 111 and high-stage compression mechanism 112. This configuration can lower the temperature of a refrigerant after the refrigerant is subjected to the compression as compared with the case of compression of a refrigerant until the refrigerant has the same pressure as in this configuration by using a single-stage compressor.
- the temperature of the refrigerant discharged from the compressor can be kept relatively low, thereby preventing the denaturing of a lubricating oil in the refrigerant and the damage of piping and the sealing member of the piping.
- refrigeration apparatus 1 includes ejector 13, gas-liquid separator 18, split heat exchanger 14, auxiliary throttle mechanism 15, and auxiliary compression mechanism 19 in the same manner as refrigeration apparatus 1 according to Embodiment 2.
- the refrigeration capacity of refrigeration apparatus 1 thus can be increased, and also the refrigeration efficiency can be improved.
- FIG. 4 is a graph showing the results of electric power simulation in the refrigeration apparatuses according to Embodiment 3 and a reference example.
- the refrigeration apparatus according to the reference example differs from refrigeration apparatus 1 illustrated in FIG. 3 in the following points.
- the refrigeration apparatus according to the reference example has the following features.
- the abscissa represents the evaporation temperature (°C) in evaporator 17, and the ordinate represents the input power (kW) of auxiliary compression mechanism 19.
- the abscissa represents the evaporation temperature (°C) in evaporator 17, and the ordinate represents the total input power (kW) of auxiliary compression mechanism 19 and main compression mechanism 11.
- the simulation conditions are as follows.
- refrigeration system 1 can reduce the input power as compared with the reference example over a wide range of evaporation temperatures in both cases of the input power to auxiliary compression mechanism 19 alone and the total input power to auxiliary compression mechanism 19 and main compression mechanism 11.
- Refrigeration apparatus 1, which includes ejector 13, gas-liquid separator 18, split heat exchanger 14, auxiliary throttle mechanism 15, and auxiliary compression mechanism 19 disposed in refrigerant circuit 4 as illustrated in FIG. 2 or 3 can efficiently obtain the required refrigeration capacity regardless of the temperature of a refrigerant in evaporator 17.
- the present disclosure can be widely used for showcases and other refrigeration apparatuses that use refrigeration circuits.
Landscapes
- 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)
- Devices That Are Associated With Refrigeration Equipment (AREA)
Abstract
A refrigeration apparatus includes a main compression mechanism, a gas cooler, a main throttle mechanism, and an evaporator, and allows circulation of a refrigerant containing carbon dioxide. The refrigeration apparatus includes a split heat exchanger including a first flow channel and a second flow channel, in which the first flow channel is disposed at a site downstream of the gas cooler and upstream of the main throttle mechanism, and part of a refrigerant flowing out of the first flow channel flows into the second flow channel; an auxiliary throttle mechanism that throttles a refrigerant that is to flow into the second flow channel; and an ejector including a nozzle and a suction part, in which the nozzle is disposed at a site downstream of the main compression mechanism and upstream of the first flow channel, and the suction part sucks in a refrigerant flowing out of the second flow channel.
Description
- The present disclosure relates to a refrigeration apparatus in which a refrigerant containing carbon dioxide circulates.
- Conventionally, a refrigeration apparatus includes a refrigeration cycle formed from a compression section, a gas cooler, a throttle section, an evaporator, and the like. A refrigerant compressed in the compression section radiates heat in the gas cooler, and is then decompressed in the throttle section and evaporates in the evaporator. As the refrigerant evaporates, the surrounding air is cooled.
- In recent years, chlorofluorocarbon-based refrigerants have become unavailable for use in this type of refrigeration apparatuses due to, for example, natural environmental issues. For this reason, refrigeration apparatuses that use carbon dioxide, a natural refrigerant, as an alternative to chlorofluorocarbon-based refrigerants have been developed. The carbon dioxide refrigerant, which is a refrigerant having large difference between high and low pressures, is known to have a low critical pressure, so that when the carbon dioxide refrigerant is compressed, the refrigerant becomes in a supercritical state on the high pressure side of a refrigerant cycle (see, for example, Patent Literature (hereinafter abbreviated as "PTL") 1).
- In view of this characteristics of the refrigerant, a refrigeration cycle utilizing an ejector has been developed to improve the coefficient of performance of the refrigeration cycle (see, for example, PTL 2).
-
- NPL 1
Japanese Examined Patent Application Publication No. H7-18602 - NPL 2
Japanese Patent No. 3322263 - An object of the present disclosure is to improve the performance of a refrigeration apparatus which uses a refrigerant containing carbon dioxide and utilizes an ejector.
- A refrigeration apparatus according to the present disclosure includes a main compression mechanism, a gas cooler, a main throttle mechanism, and an evaporator, and allows circulation of a refrigerant containing carbon dioxide. The refrigeration apparatus includes a split heat exchanger including a first flow channel and a second flow channel, in which the first flow channel is disposed at a site downstream of the gas cooler and upstream of the main throttle mechanism, and part of a refrigerant flowing out of the first flow channel flows into the second flow channel; an auxiliary throttle mechanism that throttles a refrigerant that is to flow into the second flow channel; and an ejector including a nozzle and a suction part, in which the nozzle is disposed at a site downstream of the main compression mechanism and upstream of the first flow channel, and the suction part sucks in a refrigerant flowing out of the second flow channel.
- The present disclosure is capable of improving the performance of a refrigeration apparatus which uses a refrigerant containing carbon dioxide and uses an ejector.
-
-
FIG. 1 illustrates a refrigerant circuit of a refrigeration apparatus according toEmbodiment 1; -
FIG. 2 illustrates a refrigerant circuit of a refrigeration apparatus according toEmbodiment 2; -
FIG. 3 illustrates a refrigerant circuit of a refrigeration apparatus according toEmbodiment 3; and -
FIG. 4 is a graph showing the results of electric power simulation in the refrigeration apparatuses according toEmbodiment 3 and a reference example. - Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.
-
FIG. 1 illustrates a refrigerant circuit ofrefrigeration apparatus 1 according toEmbodiment 1.Refrigeration apparatus 1 according to the present embodiment includesrefrigerator unit 2 installed in, for example, an indoor machine room or an outdoor environment, andload device 3, for example, a showcase installed in a supermarket or the like.Refrigerator unit 2 andload device 3 are connected with each other by refrigerant pipe (liquid pipe) 31 andrefrigerant pipe 32 viaunit outlet 2out and unit inlet 2in to formpredetermined refrigerant circuit 4.Load device 3 may be a cooling coil of a food warehouse or the like, or a cooling device for cooling a refrigerant such as water. - Carbon dioxide (R744), whose pressure on the high pressure side may become equal to or higher than the critical pressure (supercritical), circulates as a refrigerant in
refrigerant circuit 4. The refrigerant may consist only of carbon dioxide, or may be a mixed refrigerant containing carbon dioxide and other substances. The mixed refrigerant may contain carbon dioxide and, for example, one or more of R32, R41, R134a, R125, R152a, propane and dimethyl ether. Each arrow shown inFIG. 1 indicates the flow of a refrigerant. - The lubricating oil that circulates in
refrigerant circuit 4 together with the refrigerant is, for example, mineral oil, alkylbenzene oil, ether oil, ester oil, or PAG (polyalkyl glycol). -
Refrigerant circuit 4 includesmain compression mechanism 11,gas cooler 12,ejector 13,split heat exchanger 14, andauxiliary throttle mechanism 15 inrefrigerator unit 2.Refrigerant circuit 4 includesmain throttle mechanism 16 andevaporator 17 inload device 3. -
Main compression mechanism 11, which is a frequency-variable compressor, has one or more compression mechanism parts, sucks a refrigerant in a gas-phase (i.e., gas-phase refrigerant), and discharges the refrigerant having a high temperature and high pressure. - The refrigerant discharged from
main compression mechanism 11 passes throughpipe 21 to flow intogas cooler 12. -
Gas cooler 12 lowers the temperature of the refrigerant by exchanging heat between the refrigerant and the outside air supplied by a blower for the gas cooler (not illustrated). Alternatively,gas cooler 12 may exchange heat between the refrigerant and water supplied by a water pump for the gas cooler. - The refrigerant flowing out of
gas cooler 12 passes throughpipe 22 to flow intonozzle 131 ofejector 13. Nozzle 131 is configured in such a way that the opening degree thereof can be adjusted. When the opening degree ofnozzle 131 increases, the flow velocity of the refrigerant, which flows in fromnozzle 131 and passes throughejector 13, decreases, and when the opening degree decreases, the flow velocity of the refrigerant increases. - The refrigerant flowing into
nozzle 131 expands while mixing with a gas-phase refrigerant sucked in from suction part 132 (which will be described below) and flows out ofejector 13 in a gas-liquid mixed state. When the flow velocity of the refrigerant flowing in fromnozzle 131 and passing throughejector 13 increases, the static pressure inejector 13 decreases, so that the suction pressure insuction part 132 decreases (suction becomes easier). When the flow velocity of the refrigerant flowing in fromnozzle 131 and passing throughejector 13 decreases, meanwhile, the static pressure inejector 13 increases, so that the suction pressure insuction part 132 increases (suction becomes more difficult). - The refrigerant flowing out of
ejector 13 passes throughpipe 23 to flow intofirst flow channel 141 of splitheat exchanger 14. - The refrigerant flowing into
first flow channel 141 flows out offirst flow channel 141 with the temperature of the refrigerant lowered by exchanging heat with a refrigerant that flows through second flow channel 142 (which will be described below). - The refrigerant flowing out of
first flow channel 141 partly passes throughpipe 24,unit outlet 2out, andrefrigerant pipe 31 to flow intomain throttle mechanism 16.Main throttle mechanism 16 is, for example, an electric expansion valve whose opening degree can be adjusted. - In addition, there is
branch part 25 atpipe 24 between the ends of the pipe.Branch pipe 26 branching off frompipe 24 is connected tobranch part 25. The refrigerant flowing out offirst flow channel 141 partly passes throughbranch pipe 26 to flow intoauxiliary throttle mechanism 15.Auxiliary throttle mechanism 15 is, for example, an electric expansion valve whose opening degree can be adjusted. -
Auxiliary throttle mechanism 15 expands and vaporizes the refrigerant flowing intoauxiliary throttle mechanism 15. The temperature of the refrigerant is lowered during the procedure. - The refrigerant flowing out of
auxiliary throttle mechanism 15 is in a gas-liquid mixed state, and passes throughpipe 27 to flow intosecond flow channel 142 ofsplit heat exchanger 14. - The refrigerant flowing into
second flow channel 142 exchanges heat with a refrigerant passing throughfirst flow channel 141 to lower the temperature of the refrigerant passing throughfirst flow channel 141 as described above, and then flows out ofsecond flow channel 142. - The refrigerant flowing out of
second flow channel 142 passes throughpipe 28 and is sucked intosuction part 132 ofejector 13. The refrigerant sucked intoejector 13 fromsuction part 132 mixes with a refrigerant sucked fromnozzle 131. - On the other hand, the refrigerant in a liquid-phase passing through
branch part 25 to flow intomain throttle mechanism 16 is expanded bymain throttle mechanism 16 which is, for example, an electric expansion valve. The refrigerant flowing out ofmain throttle mechanism 16 flows intoevaporator 17 viarefrigerant pipe 33, and is completely evaporated inevaporator 17. The refrigerant flowing throughevaporator 17 exchanges heat with a fluid inload device 3, for example, air, and cools the air. The fluid inload device 3 may be another refrigerant (for example, water), which is to be cooled by the refrigerant circulating inrefrigerant circuit 4. - The refrigerant flowing out of
evaporator 17 passes throughrefrigerant pipe 32, unit inlet 2in andpipe 29, and is sucked intomain compression mechanism 11. -
Refrigerator unit 2 includescontrol device 50 that controls theentire refrigeration apparatus 1. Low pressure sensor 51 (herein also referred to as "third pressure sensor"), which detects the pressure (low pressure) of the refrigerant to be sucked intomain compression mechanism 11, is attached at a site downstream ofmain throttle mechanism 16 and upstream ofmain compression mechanism 11, for example, atpipe 29. A value detected bylow pressure sensor 51 is transmitted to controldevice 50. - The value detected by
low pressure sensor 51 indicates the evaporation pressure of a refrigerant inevaporator 17, that is, the temperature of the refrigerant inevaporator 17.Control device 50 can adjust the temperature of the refrigerant inevaporator 17 and thus the temperature of a fluid inload device 3 by adjusting the operating frequency ofmain compression mechanism 11 based on the detection result fromlow pressure sensor 51. In other words,control device 50 can causemain compression mechanism 11 to perform an operation according to the refrigeration capacity required inload device 3. - The carbon dioxide-containing refrigerant can generate a fluid of desired temperature and quantity in
evaporator 17 by repeating the above described cycle. - The
refrigeration apparatus 1 according toEmbodiment 1 includesejector 13, splitheat exchanger 14, andauxiliary throttle mechanism 15 as described above.Ejector 13 can expand a refrigerant that has become in a high pressure state without requiring power.Split heat exchanger 14 andauxiliary throttle mechanism 15 can lower the temperature of a refrigerant that has flowed out ofejector 13 before the refrigerant flows intomain throttle mechanism 16.Main throttle mechanism 16 can expand the refrigerant having passed throughsplit heat exchanger 14 to lower its temperature. In other words,refrigeration apparatus 1 according toEmbodiment 1 is capable of adjusting the pressure on the high-pressure side (discharge side of main compression mechanism 11) while obtaining a desired refrigeration capacity inload device 3 by virtue of the presence ofejector 13, splitheat exchanger 14, andauxiliary throttle mechanism 15 in the refrigeration apparatus. That is,refrigeration apparatus 1 can appropriately operatemain compression mechanism 11 according to the temperature of the outside air or water supplied togas cooler 12. - In
Embodiment 1,ejector 13 is disposed between gas cooler 12 andfirst flow channel 141 ofsplit heat exchanger 14. However,ejector 13 may be disposed at any site downstream ofmain compression mechanism 11 and upstream offirst flow channel 141. For example,ejector 13 may be disposed at a site downstream ofmain compression mechanism 11 and upstream ofgas cooler 12. This disposition allows for efficient generation of cooled fluid (e.g., air or water) of desired temperature and quantity, in addition to the effects described above. -
FIG. 2 illustrates a refrigerant circuit ofrefrigeration apparatus 1 according toEmbodiment 2. The description of matters common toEmbodiment 1 may be omitted. Conversely, the description for the present embodiment may apply toEmbodiment 1. -
Refrigeration apparatus 1 according to the present embodiment includes gas-liquid separator 18,auxiliary compression mechanism 19, and a transfer pressure sensor 52 (herein also referred to as "first pressure sensor"). In the present embodiment,pipe 23 connectingejector 13 withfirst flow channel 141 ofsplit heat exchanger 14 is divided intopipe 231 on the upstream side andpipe 232 on the downstream side, and gas-liquid separator 18 is disposed between these pipes. - Gas-
liquid separator 18 is a tank capable of storing a refrigerant. A refrigerant in a gas-liquid mixed state flows into gas-liquid separator 18 via the inlet connected topipe 231. In gas-liquid separator 18, the refrigerant that has flowed into gas-liquid separator 18 is separated into a gas-phase refrigerant and a liquid-phase refrigerant. - The liquid-phase refrigerant separated in gas-
liquid separator 18 flows out from the liquid-phase refrigerant outlet of gas-liquid separator 18 connected topipe 232 and flows intofirst flow channel 141 ofsplit heat exchanger 14. - The gas-phase refrigerant separated in gas-
liquid separator 18 flows out from the gas-phase refrigerant outlet of gas-liquid separator 18 connected topipe 41. The gas-phase refrigerant flowing out of the gas-phase refrigerant outlet passes throughpipe 41 and is sucked intoauxiliary compression mechanism 19.Transfer pressure sensor 52 is disposed atpipe 41.Transfer pressure sensor 52 detects the pressure of a refrigerant that is to flow intomain throttle mechanism 16. A value detected bytransfer pressure sensor 52 is transmitted to controldevice 50. -
Transfer pressure sensor 52 may be disposed at any site other thanpipe 41 when thetransfer pressure sensor 52 can detect the pressure of the refrigerant that is to flow intomain throttle mechanism 16.Transfer pressure sensor 52 may be disposed, for example, atpipe 231, gas-liquid separator 18,pipe 232,first flow channel 141,pipe 24,branch part 25,branch pipe 26, orrefrigerant pipe 31. -
Auxiliary compression mechanism 19 is, for example, a compressor including an airtight container, an electric element that serves as a drive element housed in internal space of the airtight container, and a rotary compression element driven by a rotating shaft of the electric element. - A refrigerant compressed by
auxiliary compression mechanism 19 is discharged to mergingpipe 42. Mergingpipe 42 is connected topipe 21 at mergingpart 43 that is provided between the ends ofpipe 21, downstream ofmain compression mechanism 11 and upstream ofgas cooler 12. The refrigerant discharged to mergingpipe 42 fromauxiliary compression mechanism 19 passes through mergingpipe 42 and mergingpart 43 to join a refrigerant inpipe 21 discharged frommain compression mechanism 11. -
Refrigeration apparatus 1 according to the present embodiment includes high pressure sensor 53 (herein also referred to as "second pressure sensor") and outside air temperature sensor 54 (herein also referred to as "first temperature sensor"). Values detected by those sensors are transmitted to controldevice 50. -
High pressure sensor 53 detects the pressure (high pressure) of a refrigerant discharged frommain compression mechanism 11, and may be disposed anywhere, in so far as the high pressure sensor can detect this pressure. In the present embodiment,high pressure sensor 53 is disposed atpipe 22, but may be disposed atpipe 21 or atgas cooler 12. - Outside
air temperature sensor 54 detects the outside air temperature, that is, the temperature of a fluid, for cooling the refrigerant, in gas cooler 12. Outsideair temperature sensor 54 is disposed, for example, in the vicinity ofgas cooler 12.Gas cooler 12 is not necessarily limited to a cooler that cools a refrigerant with outside air, and may be, for example, a cooler that cools the refrigerant with water. In this case, the first temperature sensor is a water temperature sensor in place of outsideair temperature sensor 54. -
Refrigeration apparatus 1 according to the present embodiment includes transfer temperature sensor 55 (herein also referred to as "second temperature sensor") and second flow channel inlet temperature sensor 56 (herein also referred to as "third temperature sensor"). Values detected by those sensors are transmitted to controldevice 50. -
Transfer temperature sensor 55 detects the temperature of a refrigerant to be supplied tomain throttle mechanism 16, and may be disposed anywhere, in so far as the transfer temperature sensor can detect this temperature. In the present embodiment,transfer temperature sensor 55 is disposed atpipe 24, but may be disposed atbranch part 25 orbranch pipe 26, or may be disposed atrefrigerant pipe 31. - Second flow channel
inlet temperature sensor 56 detects the temperature of a refrigerant that is to flow intosecond flow channel 142 ofsplit heat exchanger 14, and is disposed atpipe 27. - In
refrigeration apparatus 1 according to the present embodiment, a refrigerant circulates as follows. -
Main compression mechanism 11 sucks a refrigerant in a gas-phase state and discharges the refrigerant in a high pressure state. The refrigerant discharged frommain compression mechanism 11 passes throughpipe 21 to flow intogas cooler 12. The refrigerant whose temperature is lowered in the gas cooler passes throughpipe 22 to flow intonozzle 131 ofejector 13. The refrigerant flowing intonozzle 131 expands while mixing with a gas-phase refrigerant sucked in fromsuction part 132 and flows out ofejector 13 in a gas-liquid mixed state. - The refrigerant flowing out of
ejector 13 passes throughpipe 231 to flow into gas-liquid separator 18. In gas-liquid separator 18, the refrigerant is separated into a gas-phase refrigerant and a liquid-phase refrigerant. The liquid-phase refrigerant from the inside of gas-liquid separator 18 passes throughpipe 232 and flows intofirst flow channel 141 ofsplit heat exchanger 14. When the liquid-phase refrigerant passes throughfirst flow channel 141, the liquid-phase refrigerant exchanges heat with a refrigerant passing throughsecond flow channel 142 ofsplit heat exchanger 14 and is cooled. - The liquid-phase refrigerant flowing out of
first flow channel 141 passes throughpipe 24,branch part 25,unit outlet 2out, andrefrigerant pipe 31 to flow intomain throttle mechanism 16. The refrigerant that flows intomain throttle mechanism 16 is throttled and expanded bymain throttle mechanism 16. The refrigerant flowing out ofmain throttle mechanism 16 flows intoevaporator 17 viarefrigerant pipe 33, and is evaporated. At this time, the refrigerant exchanges heat with the surrounding air to generate cold air. Depending on the application of theload device 3, the fluid to be subjected to the heat exchange inevaporator 17 does not have to be air. For example,load device 3 may cool water to generate cold water. The gas-phase refrigerant flowing out ofevaporator 17 passes throughrefrigerant pipe 32, unit inlet 2in andpipe 29, and is sucked intomain compression mechanism 11 again. - Further, the liquid-phase refrigerant, which is branched off at
branch part 25 and flows intobranch pipe 26, flows intoauxiliary throttle mechanism 15. The refrigerant that flows intoauxiliary throttle mechanism 15 is throttled and expanded byauxiliary throttle mechanism 15. The refrigerant flowing out ofauxiliary throttle mechanism 15 flows intosecond flow channel 142 ofsplit heat exchanger 14 viapipe 27, and is evaporated. The refrigerant flowing intosecond flow channel 142 exchanges heat with a refrigerant passing throughfirst flow channel 141 to lower the temperature of the refrigerant passing throughfirst flow channel 141. The refrigerant flowing out ofsecond flow channel 142 passes throughpipe 28 and is sucked fromsuction part 132 ofejector 13. The refrigerant sucked fromsuction part 132 mixes with a refrigerant flowing intonozzle 131 inejector 13, and then flows out ofejector 13 and flows into gas-liquid separator 18 again. - The gas-phase refrigerant from the inside of gas-
liquid separator 18 passes throughpipe 41 and is sucked intoauxiliary compression mechanism 19. The refrigerant sucked intoauxiliary compression mechanism 19 is compressed byauxiliary compression mechanism 19 until the refrigerant has a pressure equal to the pressure of a refrigerant at the outlet ofmain compression mechanism 11, and then discharged to mergingpipe 42. The refrigerant discharged fromauxiliary compression mechanism 19 to mergingpipe 42 joins the refrigerant inpipe 21 discharged frommain compression mechanism 11 via mergingpart 43. - In the present embodiment,
auxiliary compression mechanism 19 can reduce the pressure in gas-liquid separator 18, that is, can lower the temperature of a refrigerant in gas-liquid separator 18. This configuration can lower the temperature of a refrigerant supplied toevaporator 17. - In addition,
auxiliary compression mechanism 19 sucks a gas-phase refrigerant from the inside of gas-liquid separator 18 (the refrigerant whose pressure is relatively high), but not a gas-phase refrigerant flowing out of second flow channel 142 (the refrigerant whose pressure is reduced after passing through auxiliary throttle mechanism 15). The gas-phase refrigerant flowing out ofsecond flow channel 142 is sucked byejector 13. Therefore, the pressure of the refrigerant passing throughsecond flow channel 142 can be reduced by the action ofejector 13 without increasing the power (that is, the input power) ofauxiliary compression mechanism 19, and further, the temperature of the refrigerant passing throughsecond flow channel 142 can be lowered. Lowering the temperature of the refrigerant passing throughsecond flow channel 142 can lower the temperature of a refrigerant flowing out offirst flow channel 141. This configuration can lower the temperature of a refrigerant supplied toevaporator 17. The refrigeration capacity ofrefrigeration apparatus 1 thus can be increased, and also the refrigeration efficiency can be improved. - In the present embodiment,
control device 50 adjusts the operating frequency ofauxiliary compression mechanism 19 based on the detection result fromtransfer pressure sensor 52. Accordingly, the transfer pressure, that is, the pressure of a refrigerant supplied tomain throttle mechanism 16 can be set to a predetermined value. It becomes thus easier to set the pressure of a refrigerant after the refrigerant is throttled bymain throttle mechanism 16 to a predetermined value, and as a result, setting the pressure and temperature of a refrigerant flowing intoevaporator 17 to predetermined values becomes easier. This configuration allowsevaporator 17 to stably generate cold air of desired temperature and quantity. - In addition,
control device 50 adjusts the opening degree ofnozzle 131 ofejector 13 based on the detection results fromhigh pressure sensor 53 and from outsideair temperature sensor 54 in the present embodiment. That is,control device 50 adjusts the discharge pressure ofmain compression mechanism 11, namely the pressure of a refrigerant in gas cooler 12, based on the temperature of a fluid for exchanging heat with the refrigerant in gas cooler 12. - Specifically, when the outside air temperature rises, i.e., the detection value from outside
air temperature sensor 54 increases,control device 50 can increase the pressure of a refrigerant in gas cooler 12 by reducing the opening degree ofnozzle 131 in such a way that the value detected byhigh pressure sensor 53 becomes a target value. The flow velocity of the refrigerant inejector 13 then increases, and the pressure of a refrigerant sucked fromsuction part 132 decreases. As a result, the temperature of the refrigerant supplied fromsplit heat exchanger 14 tomain throttle mechanism 16 decreases. When the outside air temperature falls, i.e., the detection value from outsideair temperature sensor 54 decreases, meanwhile,control device 50 can reduce the pressure of a refrigerant in gas cooler 12 by increasing the opening degree ofnozzle 131 in such a way that the value detected byhigh pressure sensor 53 becomes a target value. The flow velocity of the refrigerant inejector 13 then decreases, and the pressure of a refrigerant sucked fromsuction part 132 increases. As a result, the temperature of a refrigerant supplied fromsplit heat exchanger 14 tomain throttle mechanism 16 increases. The control as described above can optimize the operating state ofmain compression mechanism 11, namely the power consumption ofmain compression mechanism 11, thereby improving energy conservation ofrefrigeration apparatus 1. - In addition,
control device 50 adjusts the opening degree ofauxiliary throttle mechanism 15 based on the detection results fromtransfer temperature sensor 55 and from second flow channelinlet temperature sensor 56 in the present embodiment. - Specifically, the opening degree of
auxiliary throttle mechanism 15 is adjusted in such a way that the value detected bytransfer temperature sensor 55 approaches the value detected by second flow channelinlet temperature sensor 56. The control as described above can lower the temperature of a refrigerant supplied toevaporator 17 viamain throttle mechanism 16. The refrigeration capacity ofrefrigeration apparatus 1 thus can be increased, and also the refrigeration efficiency can be improved. - The control to adjust the opening degree of
auxiliary throttle mechanism 15 based on the detection results fromtransfer temperature sensor 55 and from second flow channelinlet temperature sensor 56 is particularly effective when the opening degree ofnozzle 131 ofejector 13 changes due to changes in the outside temperature and/or the like. In other words, when the pressure of a refrigerant sucked fromsuction part 132 fluctuates due to a change in the opening degree ofnozzle 131, the temperature of a refrigerant flowing intosecond flow channel 142 changes. As a result, the temperature of a refrigerant flowing out offirst flow channel 141 and supplied tomain throttle mechanism 16 may change. Even in such a case, adjusting the opening degree ofauxiliary throttle mechanism 15 based on the detection results fromtransfer temperature sensor 55 and from second flow channelinlet temperature sensor 56 can still maintain the temperature of the refrigerant supplied tomain throttle mechanism 16 at a desired value. -
FIG. 3 illustrates a refrigerant circuit ofrefrigeration apparatus 1 according toEmbodiment 3. The description of matters common toEmbodiments Embodiments - In
refrigeration apparatus 1 according to the present embodiment,main compression mechanism 11 includes low-stage compression mechanism 111 and high-stage compression mechanism 112.Refrigeration apparatus 1 according to the present embodiment also includeintercooler 121.Intercooler 121 is disposed between low-stage compression mechanism 111 and high-stage compression mechanism 112 inrefrigerant circuit 4 viapipe 44 on the upstream side andpipe 45 on the downstream side. -
Main compression mechanism 11 is, for example, an internal intermediate-pressure two-stage compression type rotary compressor.Main compression mechanism 11 includes an airtight container and a rotary compression mechanism part. The rotary compression mechanism part includes an electric element that serves as a drive element housed in an upper portion of the internal space of the airtight container, and a first rotary compression element (low-stage compression mechanism 111) and a second rotary compression element (high-stage compression mechanism 112) disposed below the electric element.Main compression mechanism 11 is a two-stage compressor including the first rotary compression element and the second rotary compression element driven by the same rotary shaft (rotary shaft of the electric element). In such a two-stage compressor, the excluded volume ratio between the low-stage side and the high-stage side is predetermined, and the intermediate pressure is determined according to the excluded volume ratio. Low-stage compression mechanism 111 and high-stage compression mechanism 112 may be single-stage compression compressors that are independent of each other. - Low-
stage compression mechanism 111 compresses a refrigerant having a low pressure sucked intomain compression mechanism 11 from the low-pressure side ofrefrigerant circuit 4 viapipe 29, increases the pressure of the refrigerant to an intermediate pressure, and discharges the refrigerant. High-stage compression mechanism 112 sucks in the refrigerant having an intermediate pressure discharged from low-stage compression mechanism 111, compresses the refrigerant until the refrigerant has a high pressure, and discharges the refrigerant to the high-pressure side ofrefrigerant circuit 4.Main compression mechanism 11 is a frequency-variable compressor.Control device 50 controls the rotation speeds of low-stage compression mechanism 111 and high-stage compression mechanism 112 by changing the operating frequency of the electric element. - Formed on the side surface of the airtight container of
main compression mechanism 11 are a low-stage side suction port communicating with low-stage compression mechanism 111, a low-stage side discharge port communicating with the inside of the airtight container, a high-stage side suction port communicating with high-stage compression mechanism 112, and a high-stage side discharge port. One end ofpipe 29 is connected to the low-stage side suction port ofmain compression mechanism 11, and the other end ofpipe 29 is connected torefrigerant pipe 32 at unit inlet 2in. - A refrigerant gas having a low pressure sucked into the low-pressure part of low-
stage compression mechanism 111 from the low-stage side suction port is subjected to the first-stage compression by low-stage compression mechanism 111 to have an intermediate pressure, and discharged into the airtight container. As a result, the pressure inside the airtight container becomes an intermediate pressure. - One end of
pipe 44 is connected to the low-stage side discharge port ofmain compression mechanism 11 from which the refrigerant gas having the intermediate pressure in the airtight container is discharged, and the other end ofpipe 44 is connected to the inlet ofintercooler 121.Intercooler 121 cools the intermediate pressure refrigerant gas discharged from low-stage compression mechanism 111. One end ofpipe 45 is connected to the outlet ofintercooler 121. The other end ofpipe 45 is connected to the high-stage side suction port ofmain compression mechanism 11. - The intermediate pressure refrigerant gas sucked into high-
stage compression mechanism 112 from the high-stage side suction port ofmain compression mechanism 11 is subjected to the second-stage compression by high-stage compression mechanism 112 to become a refrigerant gas having high temperature and high pressure. - One end of
pipe 21 is connected to the high-stage side discharge port provided on the high-pressure chamber side of high-stage compression mechanism 112 inmain compression mechanism 11, and the other end ofpipe 21 is connected to the inlet ofgas cooler 12. An oil separator (not illustrated) may be provided atpipe 21 between the ends of the pipe. The oil separated from the refrigerant by the oil separator is returned to the airtight container ofmain compression mechanism 11 and the airtight container ofauxiliary compression mechanism 19. -
Gas cooler 12 cools the refrigerant having a high pressure discharged frommain compression mechanism 11. A blower for the gas cooler (not illustrated) for air-coolinggas cooler 12 is provided in the vicinity ofgas cooler 12. In the present embodiment,gas cooler 12 is provided in parallel with above describedintercooler 121, and the coolers are provided in the same air passage.Gas cooler 12 andintercooler 121 may be water-cooled. In this case, a water pump for the gas cooler is provided in place of the blower for the gas cooler, and water is input to the gas cooler and the intercooler in parallel. - One end of
pipe 22 is connected to the outlet ofgas cooler 12, and the other end ofpipe 22 is connected to the inlet ofnozzle 131 ofejector 13. - In
refrigeration apparatus 1 according to the present embodiment,main compression mechanism 11 includes low-stage compression mechanism 111 and high-stage compression mechanism 112.Intercooler 121 is disposed between low-stage compression mechanism 111 and high-stage compression mechanism 112. This configuration can lower the temperature of a refrigerant after the refrigerant is subjected to the compression as compared with the case of compression of a refrigerant until the refrigerant has the same pressure as in this configuration by using a single-stage compressor. Therefore, even with a refrigerant with a high compression ratio, such as a carbon dioxide-containing refrigerant, the temperature of the refrigerant discharged from the compressor can be kept relatively low, thereby preventing the denaturing of a lubricating oil in the refrigerant and the damage of piping and the sealing member of the piping. - In addition,
refrigeration apparatus 1 according to the present embodiment includesejector 13, gas-liquid separator 18, splitheat exchanger 14,auxiliary throttle mechanism 15, andauxiliary compression mechanism 19 in the same manner asrefrigeration apparatus 1 according toEmbodiment 2. The refrigeration capacity ofrefrigeration apparatus 1 thus can be increased, and also the refrigeration efficiency can be improved. The advantages ofEmbodiments FIG. 4 . -
FIG. 4 is a graph showing the results of electric power simulation in the refrigeration apparatuses according toEmbodiment 3 and a reference example. The refrigeration apparatus according to the reference example differs fromrefrigeration apparatus 1 illustrated inFIG. 3 in the following points.
The refrigeration apparatus according to the reference example has the following features. - No
ejector 13 is present. - A gas-phase refrigerant flowing out of gas-
liquid separator 18 does not flow intoauxiliary compression mechanism 19, but flows via a throttle mechanism into a site betweenauxiliary throttle mechanism 15 andsecond flow channel 142. - A gas-phase refrigerant flowing out of
second flow channel 142 does not flow intosuction part 132 ofejector 13, but flows intoauxiliary compression mechanism 19. - In the graph on the left side of
FIG. 4 , the abscissa represents the evaporation temperature (°C) inevaporator 17, and the ordinate represents the input power (kW) ofauxiliary compression mechanism 19. In the graph on the right side ofFIG. 4 , the abscissa represents the evaporation temperature (°C) inevaporator 17, and the ordinate represents the total input power (kW) ofauxiliary compression mechanism 19 andmain compression mechanism 11. The simulation conditions are as follows. - Volumetric efficiency = Compression efficiency = 1
- Refrigerant temperature at the outlet of gas cooler 12 = 35°C
- Refrigerant temperature at the outlet of
intercooler 121 = 35°C - Refrigerant pressure at the outlet of gas cooler 12 = 9 MPa
- Refrigerant pressure (transfer pressure) at the inlet of
main throttle mechanism 16 = 6.5 MPa - Refrigerant temperature at the inlet of
main throttle mechanism 16 = 13.5°C - Refrigerant temperature at the inlet of
main compression mechanism 11 = 18°C - Excluded volume ratio in
main compression mechanism 11 = 70% - Power recovery rate of
ejector 13 = 70% - As shown in the graphs,
refrigeration system 1 according toEmbodiment 3 can reduce the input power as compared with the reference example over a wide range of evaporation temperatures in both cases of the input power toauxiliary compression mechanism 19 alone and the total input power toauxiliary compression mechanism 19 andmain compression mechanism 11.Refrigeration apparatus 1, which includesejector 13, gas-liquid separator 18, splitheat exchanger 14,auxiliary throttle mechanism 15, andauxiliary compression mechanism 19 disposed inrefrigerant circuit 4 as illustrated inFIG. 2 or3 , can efficiently obtain the required refrigeration capacity regardless of the temperature of a refrigerant inevaporator 17. - The present disclosure can be widely used for showcases and other refrigeration apparatuses that use refrigeration circuits.
-
- 1 Refrigeration apparatus
- 2 Refrigerator unit
- 2out Unit outlet
- 2in Unit inlet
- 3 Load device
- 4 Refrigerant circuit
- 11 Main compression mechanism
- 111 Low-stage compression mechanism
- 112 High-stage compression mechanism
- 12 Gas cooler
- 121 Intercooler
- 13 Ejector
- 131 Nozzle
- 132 Suction part
- 14 Split heat exchanger
- 141 First flow channel
- 142 Second flow channel
- 15 Auxiliary throttle mechanism
- 16 Main throttle mechanism
- 17 Evaporator
- 18 Gas-liquid separator
- 19 Auxiliary compression mechanism
- 21, 22, 23, 24, 27, 28, 29, 41, 44, 45 Pipe
- 25 Branch part
- 26 Branch pipe
- 31, 32, 33 Refrigerant pipe
- 42 Merging pipe
- 43 Merging part
- 50 Control device
- 51 Low pressure sensor
- 52 Transfer pressure sensor
- 53 High pressure sensor
- 54 Outside air temperature sensor
- 55 Transfer temperature sensor
- 56 Second flow channel inlet temperature sensor
Claims (8)
- A refrigeration apparatus that includes a main compression mechanism, a gas cooler, a main throttle mechanism, and an evaporator, and allows circulation of a refrigerant containing carbon dioxide, the refrigeration apparatus comprising:a split heat exchanger including a first flow channel and a second flow channel, wherein the first flow channel is disposed at a site downstream of the gas cooler and upstream of the main throttle mechanism, and part of a refrigerant flowing out of the first flow channel flows into the second flow channel;an auxiliary throttle mechanism that throttles a refrigerant that is to flow into the second flow channel; andan ejector including a nozzle and a suction part, wherein the nozzle is disposed at a site downstream of the main compression mechanism and upstream of the first flow channel, and the suction part sucks a refrigerant flowing out of the second flow channel.
- The refrigeration apparatus according to claim 1, wherein:the nozzle is disposed at a site downstream of the gas cooler and upstream of the first flow channel.
- The refrigeration apparatus according to claim 2, further comprising:a gas-liquid separator into which a refrigerant flowing out of the ejector flows, and in which the refrigerant is subjected to gas-liquid separation; andan auxiliary compression mechanism that sucks a gas-phase refrigerant flowing out of the gas-liquid separator and discharges the sucked gas-phase refrigerant to a site upstream of the gas cooler, whereina liquid-phase refrigerant flowing out of the gas-liquid separator flows into the first flow channel.
- The refrigeration apparatus according to claim 3, further comprising:an intercooler, whereinthe main compression mechanism includes a low-stage compression mechanism that discharges a refrigerant to a site upstream of the intercooler, and a high-stage compression mechanism that sucks a refrigerant flowing out of the intercooler.
- The refrigeration apparatus according to claim 3 or 4, further comprising:a first pressure sensor that detects pressure of a refrigerant that is to flow into the main throttle mechanism, whereinoperating frequency of the auxiliary compression mechanism is adjusted based on a detection result from the first pressure sensor.
- The refrigeration apparatus according to any one of claims 3 to 5, further comprising:a second pressure sensor that detects pressure of a refrigerant that is to flow into the nozzle; and a first temperature sensor that detects a temperature of a fluid that is to exchange heat with a refrigerant in the gas cooler, whereinan opening degree of the nozzle is adjusted based on a detection result from the second pressure sensor and a detection result from the first temperature sensor.
- The refrigeration apparatus according to claim 6, further comprising:a second temperature sensor that detects a temperature of a refrigerant flowing out of the first flow channel; and a third temperature sensor that detects a temperature of a refrigerant that is to flow into the second flow channel, whereinan opening degree of the auxiliary throttle mechanism is adjusted based on a detection result from the second temperature sensor and a detection result from the third temperature sensor.
- The refrigeration apparatus according to any one of claims 1 to 7, further comprising:a third pressure sensor that detects pressure of a refrigerant that is to be sucked into the main compression mechanism, whereinoperating frequency of the main compression mechanism is adjusted based on a detection result from the third pressure sensor.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2020195261A JP2022083749A (en) | 2020-11-25 | 2020-11-25 | Refrigerating device |
Publications (1)
Publication Number | Publication Date |
---|---|
EP4006443A1 true EP4006443A1 (en) | 2022-06-01 |
Family
ID=78770431
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP21209825.5A Withdrawn EP4006443A1 (en) | 2020-11-25 | 2021-11-23 | Refrigeration apparatus |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP4006443A1 (en) |
JP (1) | JP2022083749A (en) |
CN (1) | CN114543382A (en) |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0718602B2 (en) | 1989-01-09 | 1995-03-06 | シンヴェント・アクシェセルスカープ | Operation method and apparatus for supercritical vapor compression cycle |
JP3322263B1 (en) | 2000-03-15 | 2002-09-09 | 株式会社デンソー | Ejector cycle, gas-liquid separator used therefor, and water heater and heat management system using this ejector cycle |
WO2017081157A1 (en) * | 2015-11-13 | 2017-05-18 | Danfoss A/S | A vapour compression system comprising a secondary evaporator |
DE102019111309A1 (en) * | 2019-05-02 | 2020-11-05 | Technische Universität Dresden | Ejector-based cooling system and cooling method |
-
2020
- 2020-11-25 JP JP2020195261A patent/JP2022083749A/en active Pending
-
2021
- 2021-11-19 CN CN202111375652.XA patent/CN114543382A/en active Pending
- 2021-11-23 EP EP21209825.5A patent/EP4006443A1/en not_active Withdrawn
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0718602B2 (en) | 1989-01-09 | 1995-03-06 | シンヴェント・アクシェセルスカープ | Operation method and apparatus for supercritical vapor compression cycle |
JP3322263B1 (en) | 2000-03-15 | 2002-09-09 | 株式会社デンソー | Ejector cycle, gas-liquid separator used therefor, and water heater and heat management system using this ejector cycle |
WO2017081157A1 (en) * | 2015-11-13 | 2017-05-18 | Danfoss A/S | A vapour compression system comprising a secondary evaporator |
DE102019111309A1 (en) * | 2019-05-02 | 2020-11-05 | Technische Universität Dresden | Ejector-based cooling system and cooling method |
Also Published As
Publication number | Publication date |
---|---|
JP2022083749A (en) | 2022-06-06 |
CN114543382A (en) | 2022-05-27 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9523520B2 (en) | Air-conditioning apparatus | |
US9453668B2 (en) | Refrigeration cycle apparatus and refrigerant circulating method | |
JP4613916B2 (en) | Heat pump water heater | |
EP2995885B1 (en) | Binary refrigeration device | |
US20110041523A1 (en) | Charge management in refrigerant vapor compression systems | |
EP2339266B1 (en) | Refrigerating apparatus | |
WO2013111176A1 (en) | Air-conditioning device | |
JP2007139225A (en) | Refrigerating device | |
JP2011133209A (en) | Refrigerating apparatus | |
KR101220663B1 (en) | Freezing device | |
JP2013155972A (en) | Refrigeration device | |
CN108603697B (en) | Refrigerating device | |
KR20110074708A (en) | Freezing device | |
EP3862651B1 (en) | Refrigeration cycle device | |
JP2011137557A (en) | Refrigerating apparatus | |
EP4006443A1 (en) | Refrigeration apparatus | |
JP6765086B2 (en) | Refrigeration equipment | |
JP6206787B2 (en) | Refrigeration equipment | |
JP6094859B2 (en) | Refrigeration equipment | |
CN106524545B (en) | Refrigerating device | |
JP2011133208A (en) | Refrigerating apparatus | |
US11927371B2 (en) | Two stage single gas cooler HVAC cycle | |
JP2014159950A (en) | Freezer | |
CN108603696B (en) | Refrigerating device | |
JP2017172923A (en) | Refrigerating device |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION HAS BEEN PUBLISHED |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20221202 |