US20220003443A1 - Heat exchange unit - Google Patents
Heat exchange unit Download PDFInfo
- Publication number
- US20220003443A1 US20220003443A1 US17/280,571 US201917280571A US2022003443A1 US 20220003443 A1 US20220003443 A1 US 20220003443A1 US 201917280571 A US201917280571 A US 201917280571A US 2022003443 A1 US2022003443 A1 US 2022003443A1
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- US
- United States
- Prior art keywords
- heat
- refrigerant
- exchange unit
- liquid medium
- heat exchange
- 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.)
- Abandoned
Links
- 239000003507 refrigerant Substances 0.000 claims abstract description 304
- 238000001514 detection method Methods 0.000 claims abstract description 263
- 239000007788 liquid Substances 0.000 claims abstract description 241
- 238000001816 cooling Methods 0.000 claims abstract description 25
- 238000010438 heat treatment Methods 0.000 claims abstract description 21
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 34
- 230000007246 mechanism Effects 0.000 description 67
- 238000012423 maintenance Methods 0.000 description 13
- 230000005494 condensation Effects 0.000 description 11
- 238000009833 condensation Methods 0.000 description 11
- 238000009434 installation Methods 0.000 description 9
- 238000000034 method Methods 0.000 description 9
- 230000006870 function Effects 0.000 description 8
- 239000012267 brine Substances 0.000 description 6
- 230000006835 compression Effects 0.000 description 6
- 238000007906 compression Methods 0.000 description 6
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 4
- 238000004891 communication Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 238000005057 refrigeration Methods 0.000 description 4
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 3
- 238000005219 brazing Methods 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000010892 electric spark Methods 0.000 description 2
- 230000014509 gene expression Effects 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- OCKGFTQIICXDQW-ZEQRLZLVSA-N 5-[(1r)-1-hydroxy-2-[4-[(2r)-2-hydroxy-2-(4-methyl-1-oxo-3h-2-benzofuran-5-yl)ethyl]piperazin-1-yl]ethyl]-4-methyl-3h-2-benzofuran-1-one Chemical class C1=C2C(=O)OCC2=C(C)C([C@@H](O)CN2CCN(CC2)C[C@H](O)C2=CC=C3C(=O)OCC3=C2C)=C1 OCKGFTQIICXDQW-ZEQRLZLVSA-N 0.000 description 1
- UXVMQQNJUSDDNG-UHFFFAOYSA-L Calcium chloride Chemical compound [Cl-].[Cl-].[Ca+2] UXVMQQNJUSDDNG-UHFFFAOYSA-L 0.000 description 1
- 238000004378 air conditioning Methods 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000001110 calcium chloride Substances 0.000 description 1
- 229910001628 calcium chloride Inorganic materials 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 239000003673 groundwater Substances 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 239000002351 wastewater Substances 0.000 description 1
Images
Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
- F24F11/32—Responding to malfunctions or emergencies
- F24F11/36—Responding to malfunctions or emergencies to leakage of heat-exchange fluid
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F1/00—Room units for air-conditioning, e.g. separate or self-contained units or units receiving primary air from a central station
- F24F1/0007—Indoor units, e.g. fan coil units
- F24F1/0059—Indoor units, e.g. fan coil units characterised by heat exchangers
- F24F1/0063—Indoor units, e.g. fan coil units characterised by heat exchangers by the mounting or arrangement of the heat exchangers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F5/00—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
- F24F13/20—Casings or covers
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
- F24F13/22—Means for preventing condensation or evacuating condensate
- F24F13/222—Means for preventing condensation or evacuating condensate for evacuating condensate
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
- F24F13/20—Casings or covers
- F24F2013/207—Casings or covers with control knobs; Mounting controlling members or control units therein
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F13/00—Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
- F24F13/22—Means for preventing condensation or evacuating condensate
- F24F13/222—Means for preventing condensation or evacuating condensate for evacuating condensate
- F24F2013/227—Condensate pipe for drainage of condensate from the evaporator
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F2110/00—Control inputs relating to air properties
- F24F2110/50—Air quality properties
- F24F2110/65—Concentration of specific substances or contaminants
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B13/00—Compression machines, plants or systems, with reversible cycle
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B25/00—Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00
- F25B25/005—Machines, plants or systems, using a combination of modes of operation covered by two or more of the groups F25B1/00 - F25B23/00 using primary and secondary 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
- 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
Definitions
- the present disclosure relates to a heat exchange unit that exchanges heat between a refrigerant and a liquid medium sent to utilization-side equipment, to cool or heat the liquid medium.
- Patent Literature 1 discloses a heat exchange unit that cools brine or the like with a refrigerant in a heat exchanger arranged in a relay device, and sends the cooled brine or the like to utilization-side equipment.
- a flammable (including mildly flammable) refrigerant may be used in consideration of various characteristics of the refrigerant.
- a flammable refrigerant is used in the heat exchange unit, there is a possibility of ignition if the refrigerant leaks for some reason.
- a heat exchange unit exchanges heat between a liquid medium sent to utilization-side equipment and a refrigerant that is flammable, to perform at least one of cooling and heating of the liquid medium.
- the heat exchange unit includes a heat exchanger, a casing, a drain pan, and a first gas detection sensor.
- the heat exchanger exchanges heat between the refrigerant and the liquid medium.
- the casing accommodates the heat exchanger.
- the drain pan is arranged below the heat exchanger, in a lower part of the casing.
- the drain pan has a bottom plate and a side wall extending upward from the bottom plate.
- the first gas detection sensor detects the presence or absence of refrigerant gas in an internal space of the drain pan, the internal space being located above the bottom plate of the drain pan and below an upper end part of the side wall of the drain pan.
- the refrigerant gas is usually heavier than air. Therefore, when the refrigerant leaks, the leaked refrigerant gas moves downward. Therefore, in this heat exchange unit, leaked refrigerant gas tends to accumulate in the drain pan that is arranged in the lower part of the casing and receives dew condensation water generated on a pipe, the heat exchanger, and the like.
- the first gas detection sensor has a first detection element arranged in the internal space of the drain pan, and detects the presence or absence of refrigerant gas at a place where the first detection element is arranged.
- the bottom plate of the drain pan has an inclined part that is inclined with respect to a horizontal plane.
- the first detection element is arranged on a lower end side of the inclined part.
- the detection element of the first gas detection sensor is arranged on the lower end side of the inclined part where the refrigerant gas tends to accumulate, highly reliable refrigerant leakage detection is possible.
- At least one of the bottom plate and the side wall of the drain pan is provided with a drain port for discharge of water in the internal space of the drain pan.
- the first detection element is provided near the drain port.
- the detection element of the first gas detection sensor is arranged near the drain port of the drain pan that is arranged at a position where water is easily discharged, highly reliable refrigerant leakage detection is possible.
- a heat exchange unit further includes a float arranged in the internal space of the drain pan.
- the first detection element is attached to an upper surface or a side surface of the float.
- the detection element of the first gas detection sensor is attached to the upper surface or the side surface of the float, it is possible to detect refrigerant leakage even when water accumulates in the drain pan.
- a heat exchange unit further includes a second gas detection sensor.
- the second gas detection sensor has a second detection element arranged outside the casing. The second gas detection sensor detects the presence or absence of refrigerant gas at a place where the second detection element is arranged.
- refrigerant gas can be detected by the second gas detection sensor provided separately, which enhances safety.
- the casing is formed with an opening for maintenance.
- the first detection element is arranged in a space near the opening.
- the detection element of the first gas detection sensor is arranged in the space near the opening for maintenance, the detection element of the first gas detection sensor can be easily inspected and replaced.
- a heat exchange unit further includes a pump.
- the pump is arranged inside the casing.
- the pump sends the liquid medium to the utilization-side equipment.
- An inside of the casing is sectioned into at least a pump arrangement area and a refrigerant side area in plan view.
- the pump is arranged.
- a refrigerant pipe through which the refrigerant flows or the heat exchanger is arranged.
- the first detection element is arranged closer to the refrigerant side area than the pump arrangement area in plan view.
- the detection element of the first gas detection sensor is arranged, inside the casing, relatively close to the heat exchanger or the refrigerant pipe through which the refrigerant flows, highly reliable refrigerant leakage detection is possible.
- FIG. 1 is a perspective view of a heat exchange unit according to one or more embodiments.
- FIG. 2 is a schematic configuration diagram of a heat load processing system including the heat exchange unit of FIG. 1 .
- FIG. 3 is a schematic plan view of a machine room that is an installation place of the heat exchange unit of FIG. 1 .
- FIG. 4 is a schematic front view of the heat exchange unit of FIG. 1 .
- FIG. 5 is a schematic plan view of a lower part inside a casing of the heat exchange unit of FIG. 1 .
- FIG. 6 is a schematic front view of the heat exchange unit of FIG. 1 with a side plate of the casing removed.
- FIG. 7 is a schematic right side view of the heat exchange unit of FIG. 1 with a side plate of the casing removed.
- FIG. 8 is a schematic plan view of a drain pan of the heat exchange unit of FIG. 1 .
- FIG. 9 is a schematic rear view of a part of the casing of the heat exchange unit of FIG. 1 and the drain pan of FIG. 8 .
- FIG. 10 is a schematic right side view of the drain pan of FIG. 8 .
- FIG. 11A is view obtained by schematically drawing an example of a float installed in an internal space of the drain pan of FIG. 8 .
- FIG. 11B is view obtained by schematically drawing another example of the float installed in the internal space of the drain pan of FIG. 8 .
- FIG. 12 is a schematic front view of a heat exchange unit of Modified example 1B.
- FIG. 13 is a perspective view of a heat exchange unit according to one or more embodiments.
- FIG. 14 is a schematic configuration diagram of a heat load processing system including the heat exchange unit of FIG. 13 .
- FIG. 15 is a schematic plan view of a lower part inside a casing of the heat exchange unit of FIG. 13 .
- FIG. 16 is a schematic front view of the heat exchange unit of FIG. 13 with a side plate of the casing removed.
- FIG. 17 is a schematic right side view of the heat exchange unit of FIG. 13 with a side plate of the casing removed.
- FIG. 18 is a schematic rear view of a part of the casing of the heat exchange unit of FIG. 12 and a drain pan of the heat exchange unit of FIG. 12 .
- FIG. 19 is a specific example of a refrigerant used in the heat exchange units of one or more embodiments.
- a heat exchange unit 100 according to one or more embodiments and a heat load processing system 1 including the heat exchange unit 100 will be described with reference to the drawings.
- FIG. 1 is a perspective view of the heat exchange unit 100 .
- FIG. 2 is a schematic configuration diagram of the heat load processing system 1 including the heat exchange unit 100 . Note that, in FIG. 2 , an internal configuration is drawn only for one of four heat source units 300 , and drawing of an internal configuration of the other three is omitted.
- FIG. 3 is a schematic plan view of a machine room R where the heat exchange unit 100 is installed.
- FIG. 4 is a schematic front view of the heat exchange unit 100 .
- FIG. 5 is a schematic plan view of a lower part inside a casing 90 of the heat exchange unit 100 .
- FIG. 6 is a schematic front view of the heat exchange unit 100 with a side plate of the casing 90 removed.
- FIG. 7 is a schematic right side view of the heat exchange unit 100 with a side plate of the casing 90 removed.
- the heat load processing system 1 mainly includes the heat exchange unit 100 , the heat source unit 300 , and utilization-side equipment 410 .
- the heat exchange unit 100 is a unit that exchanges heat between a liquid medium and a refrigerant, to perform at least one of cooling and heating of the liquid medium.
- the heat exchange unit 100 of one or more embodiments performs both cooling and heating of the liquid medium by exchanging heat between the liquid medium and the refrigerant.
- the liquid medium cooled or heated by a liquid refrigerant in the heat exchange unit 100 is sent to the utilization-side equipment 410 .
- the liquid medium used in one or more embodiments is, for example, a heat medium such as water or brine.
- the liquid medium used as brine is, for example, an aqueous solution of sodium chloride, an aqueous solution of calcium chloride, an aqueous solution of ethylene glycol, an aqueous solution of propylene glycol, or the like.
- the liquid medium is not limited to the types exemplified here, and may be appropriately selected.
- brine is used as the liquid medium.
- the refrigerant is a flammable refrigerant.
- flammable refrigerants includes refrigerants that fall into Class 3 (higher flammability), Class 2 (flammable), and Subclass 2L (lower flammability) in the standard of ASHRAE 34 Designation and safety classification of refrigerant of the United States of America, or the standard of ISO 817 Refrigerants—Designation and safety classification.
- FIG. 19 shows a specific example of the refrigerant used in one or more embodiments. “ASHRAE Number” in FIG.
- the refrigerant to be used is R32.
- the refrigerants illustrated in FIG. 19 have a feature of having a higher density than air.
- An installation place is not limited, but the heat exchange unit 100 is installed indoors, for example.
- the heat exchange unit 100 is installed in the machine room R together with other devices (devices OD 1 to OD 3 in FIG. 3 ) as shown in FIG. 3 .
- the devices OD 1 to OD 3 include, but are not limited to, a boiler, a generator, a switchboard, and the like.
- only the heat exchange unit 100 may be installed in the machine room R.
- the heat exchange unit 100 may be installed outdoors such as on a rooftop of a building or around a building.
- the heat source unit 300 is a device that uses air as a heat source to cool or heat the refrigerant.
- the heat source unit 300 is connected to the heat exchange unit 100 via a liquid-refrigerant connection pipe 52 and a gas-refrigerant connection pipe 54 , and form a refrigerant circuit 50 together with the heat exchange unit 100 .
- the refrigerant circuit 50 mainly has a compressor 330 , a flow path switching mechanism 332 , a heat-source-side heat exchanger 340 , and a second expansion mechanism 344 of the heat source unit 300 , which will be described later, a utilization-side heat exchanger 10 and a first expansion mechanism 20 of the heat exchange unit 100 , which will be described later, and the like.
- An installation place is not limited, but the heat source unit 300 is installed, for example, on a rooftop or around of a building, or the like.
- the heat load processing system 1 has the four heat source units 300 (see FIG. 2 ). Then, the heat exchange unit 100 cools or heats the liquid medium with the refrigerant cooled or heated in the four heat source units 300 .
- the number of heat source units 300 is an example, and the number is not limited to four. The number of heat source units 300 may be, for example, one to three, or five or more.
- the utilization-side equipment 410 is equipment that uses or stores the liquid medium cooled or heated by the heat exchange unit 100 .
- the utilization-side equipment 410 is connected to the heat exchange unit 100 via a liquid medium connection pipe 420 to form a liquid medium circuit 400 .
- the liquid medium sent by a pump 60 of the heat exchange unit 100 which will be described later, circulates.
- the utilization-side equipment 410 is, for example, an air handling unit or a fan coil unit that performs air conditioning by exchanging heat between air and the liquid medium cooled or heated by the heat exchange unit 100 .
- the utilization-side equipment 410 may be, for example, manufacturing equipment that cools or heats a manufacturing device or a manufactured product by using the liquid medium cooled or heated by the heat exchange unit 100 .
- the utilization-side equipment 410 may be, for example, a tank that stores the liquid medium cooled or heated by the heat exchange unit 100 .
- the liquid medium stored in the tank as the utilization-side equipment 410 is, for example, sent to a device using the liquid medium by a pump or the like (not illustrated).
- FIG. 2 illustrates only one piece of the utilization-side equipment 410 .
- the heat load processing system 1 includes multiple pieces of utilization-side equipment, and the liquid medium cooled or heated by the heat exchange unit 100 may be sent to the multiple pieces of utilization-side equipment.
- types of the multiple pieces of utilization-side equipment may all be the same, or the multiple pieces of utilization-side equipment may include a plurality of types of equipment.
- the heat source unit 300 the liquid-refrigerant connection pipe 52 and the gas-refrigerant connection pipe 54 , the liquid medium circuit 400 , and the heat exchange unit 100 will be described in detail.
- the heat source unit 300 will be described with reference to FIG. 2 . Note that, in FIG. 2 , an internal configuration is drawn only for one of four heat source units 300 , and drawing of an internal configuration of the other three is omitted. The heat source units 300 omitted from the drawing also have a configuration similar to the heat source unit 300 described below.
- the heat source unit 300 mainly includes an in-unit refrigerant pipe 350 , the compressor 330 , the flow path switching mechanism 332 , the heat-source-side heat exchanger 340 , the second expansion mechanism 344 , a fan 342 , a gas-side shutoff valve 304 , a liquid-side shutoff valve 302 , and a heat-source-side control board 395 (see FIG. 2 ).
- the in-unit refrigerant pipe 350 is a pipe connecting between configurations of the heat source unit 300 , including the compressor 330 , the flow path switching mechanism 332 , the heat-source-side heat exchanger 340 , the second expansion mechanism 344 , the gas-side shutoff valve 304 , and the liquid-side shutoff valve 302 .
- the in-unit refrigerant pipe 350 includes a suction pipe 351 , a discharge pipe 352 , a first gas-side pipe 353 , a liquid-side pipe 354 , and a second gas-side pipe 355 (see FIG. 2 ).
- the suction pipe 351 is a pipe that connects a suction port (not illustrated) of the compressor 330 and the flow path switching mechanism 332 .
- the suction pipe 351 is provided with an accumulator (not illustrated).
- the discharge pipe 352 is a pipe that connects a discharge port (not illustrated) of the compressor 330 and the flow path switching mechanism 332 .
- the first gas-side pipe 353 is a pipe that connects the flow path switching mechanism 332 and a gas side of the heat-source-side heat exchanger 340 .
- the liquid-side pipe 354 is a pipe that connects a liquid side of the heat-source-side heat exchanger 340 and the liquid-side shutoff valve 302 . In the liquid-side pipe 354 , the second expansion mechanism 344 is arranged.
- the second gas-side pipe 355 is a pipe that connects the flow path switching mechanism 332 and the gas-side shutoff valve 304 .
- the compressor 330 suctions a low-pressure refrigerant in a refrigeration cycle through the suction pipe 351 , compresses the refrigerant by a compression mechanism (not illustrated), and discharges a high-pressure refrigerant in the refrigeration cycle after compression through the discharge pipe 352 .
- the compressor 330 is, for example, a scroll-type compressor.
- a type of the compressor 330 is not limited to the scroll type, and the compressor may be, for example, a screw type, a rotary type, or the like.
- the compressor 330 is, for example, a compressor having a variable capacity, but may be, for example, a compressor having a constant capacity.
- the flow path switching mechanism 332 is a mechanism to switch a flow direction of the refrigerant in the refrigerant circuit 50 in accordance with an operating mode of the heat load processing system 1 .
- the operating modes of the heat load processing system 1 include a mode for cooling the liquid medium (hereinafter referred to as a cooling mode) and a mode for heating the liquid medium (hereinafter referred to as a heating mode).
- the flow path switching mechanism 332 is a four-way switching valve.
- the flow path switching mechanism 332 is not limited to the four-way switching valve, and may be configured to be able to realize switching of a flow direction of the refrigerant as follows, by combining a plurality of electromagnetic valves and pipes.
- the flow path switching mechanism 332 switches the flow direction of the refrigerant in the refrigerant circuit 50 so that the refrigerant discharged by the compressor 330 is sent to the heat-source-side heat exchanger 340 . Specifically, in the cooling mode, the flow path switching mechanism 332 connects the suction pipe 351 with the second gas-side pipe 355 , and connects the discharge pipe 352 with the first gas-side pipe 353 (see a solid line in the flow path switching mechanism 332 in FIG. 2 ).
- the flow path switching mechanism 332 switches the flow direction of the refrigerant in the refrigerant circuit 50 so that the refrigerant discharged by the compressor 330 is sent to the utilization-side heat exchanger 10 of the heat exchange unit 100 .
- the flow path switching mechanism 332 connects the suction pipe 351 with the first gas-side pipe 353 , and connects the discharge pipe 352 with the second gas-side pipe 355 (see a broken line in the flow path switching mechanism 332 in FIG. 2 ).
- the heat-source-side heat exchanger 340 is a heat exchanger that exchanges heat between air around the heat source unit 300 and a refrigerant flowing inside the heat-source-side heat exchanger 340 .
- the heat-source-side heat exchanger 340 is, for example, a cross-fin type fin-and-tube heat exchanger, although the type is not limited.
- the heat-source-side heat exchanger 340 functions as a condenser (a radiator) when the operating mode of the heat load processing system 1 is in the cooling mode. Further, the heat-source-side heat exchanger 340 functions as an evaporator when the operating mode of the heat load processing system 1 is in the heating mode.
- the second expansion mechanism 344 is a mechanism that expands a refrigerant flowing through the liquid-side pipe 354 , to adjust a pressure and a flow rate of the refrigerant.
- the second expansion mechanism 344 is an electronic expansion valve whose opening degree is adjustable.
- the second expansion mechanism 344 is not limited to the electronic expansion valve.
- the second expansion mechanism 344 may be a temperature automatic expansion valve having a temperature sensing cylinder, or may be a capillary tube.
- the fan 342 is a mechanism to generate an air flow so that air passes through the heat-source-side heat exchanger 340 , in order to promote heat exchange between the refrigerant and air in the heat-source-side heat exchanger 340 .
- the fan 342 is, for example, a propeller fan, although the type is not limited.
- the liquid-side shutoff valve 302 is a valve that switches between communication and non-communication between the liquid-refrigerant connection pipe 52 and the liquid-side pipe 354 .
- One end of the liquid-side shutoff valve 302 is connected with the liquid-refrigerant connection pipe 52 , and another end of the liquid-side shutoff valve 302 is connected with the liquid-side pipe 354 (see FIG. 2 ).
- the gas-side shutoff valve 304 is a valve that switches between communication and non-communication between the gas-refrigerant connection pipe 54 and the second gas-side pipe 355 .
- One end of the gas-side shutoff valve 304 is connected with the gas-refrigerant connection pipe 54
- another end of the gas-side shutoff valve 304 is connected with the second gas-side pipe 355 (see FIG. 2 ).
- the heat-source-side control board 395 functions as a control unit 95 a together with a heat-exchange-unit side control board 95 of the heat exchange unit 100 described later.
- the control unit 95 a will be described later.
- the heat-source-side control board 395 has various electric circuits, a microcomputer including a CPU and a memory that stores a program executed by the CPU, and the like.
- the liquid-refrigerant connection pipe 52 connects the liquid-side shutoff valve 302 of the heat source unit 300 to a liquid-side connecting port 100 a of the heat exchange unit 100 , and connects the liquid-side pipe 354 of the heat source unit 300 with an in-heat-exchange-unit liquid-side pipe 56 of the heat exchange unit 100 .
- a flare joint is used for connecting the liquid-refrigerant connection pipe 52 and the liquid-side connecting port 100 a of the heat exchange unit 100 .
- a connection method between the liquid-refrigerant connection pipe 52 and the liquid-side connecting port 100 a of the heat exchange unit 100 is not limited to the connection method using the flare joint, but a connection method using a flange joint or a brazing connection may be selected, for example.
- the gas-refrigerant connection pipe 54 connects the gas-side shutoff valve 304 of the heat source unit 300 to a gas-side connecting port 100 b of the heat exchange unit 100 , and connects the second gas-side pipe 355 of the heat source unit 300 with an in-heat-exchange-unit gas-side pipe 58 of the heat exchange unit 100 .
- the gas-refrigerant connection pipe 54 and the gas-side connecting port 100 b of the heat exchange unit 100 are connected by brazing, for example.
- a connection method between the gas-refrigerant connection pipe 54 and the gas-side connecting port 100 b of the heat exchange unit 100 is not limited to the brazing connection, and a connection method using various pipe joints may be selected.
- the liquid medium circuit 400 is a circuit in which the liquid medium circulates.
- the liquid medium circuit 400 is configured by connecting, with a pipe, the utilization-side heat exchanger 10 of the heat exchange unit 100 and the utilization-side equipment 410 .
- the liquid medium circuit 400 includes the utilization-side heat exchanger 10 and the pump 60 of the heat exchange unit 100 , the utilization-side equipment 410 , an in-heat-exchange-unit first liquid medium pipe 66 , an in-heat-exchange-unit second liquid medium pipe 68 , an in-heat-exchange-unit connection pipe 67 , a first connection pipe 422 , and a second connection pipe 424 .
- the utilization-side heat exchanger 10 and the pump 60 of the heat exchange unit 100 will be described later.
- the utilization-side equipment 410 is, for example, an air handling unit or a fan coil unit. Further, for example, as described above, the utilization-side equipment 410 may be manufacturing equipment that cools or heats a manufacturing device or a manufactured product by using a liquid medium cooled or heated by the heat exchange unit 100 , or may be a tank that stores the liquid medium cooled or heated by the heat exchange unit 100 .
- the in-heat-exchange-unit first liquid medium pipe 66 is a pipe that connects a liquid medium inlet 62 of the heat exchange unit 100 and the utilization-side heat exchanger 10 (particularly, a first heat exchanger 10 a described later).
- the pump 60 is arranged in the in-heat-exchange-unit first liquid medium pipe 66 .
- the in-heat-exchange-unit second liquid medium pipe 68 is a pipe that connects the utilization-side heat exchanger 10 (particularly, a second heat exchanger 10 b described later) and a liquid medium outlet 64 of the heat exchange unit 100 .
- the in-heat-exchange-unit connection pipe 67 is a pipe that connects the first heat exchanger 10 a and the second heat exchanger 10 b , which will be described later.
- the first connection pipe 422 is a pipe that connects the utilization-side equipment 410 and the liquid medium inlet 62 of the heat exchange unit 100 .
- a connection method is not limited, the first connection pipe 422 is connected to the liquid medium inlet 62 of the heat exchange unit 100 , for example, by a flange joint.
- the first connection pipe 422 may be screwed or welded to be connected to the liquid medium inlet 62 of the heat exchange unit 100 .
- the second connection pipe 424 is a pipe that connects the liquid medium outlet 64 of the heat exchange unit 100 and the utilization-side equipment 410 .
- a connection method is not limited, the second connection pipe 424 is connected to the liquid medium outlet 64 of the heat exchange unit 100 , for example, by a flange joint.
- the second connection pipe 424 may be screwed or welded to be connected to the liquid medium outlet 64 of the heat exchange unit 100 .
- the liquid medium flows through the liquid medium circuit 400 as follows.
- the liquid medium having flowed out from the utilization-side equipment 410 flows through the first connection pipe 422 toward the liquid medium inlet 62 of the heat exchange unit 100 .
- the liquid medium having flowed into the heat exchange unit 100 from the liquid medium inlet 62 passes through the in-heat-exchange-unit first liquid medium pipe 66 to flow into the utilization-side heat exchanger 10 .
- the liquid medium passes through the utilization-side heat exchanger 10 , the liquid medium is cooled or heated by exchanging heat with the refrigerant flowing through the refrigerant circuit 50 .
- the liquid medium cooled or heated by the utilization-side heat exchanger 10 flows out from the utilization-side heat exchanger 10 , and flows through the in-heat-exchange-unit second liquid medium pipe 68 toward the liquid medium outlet 64 .
- the liquid medium having flowed out of the heat exchange unit 100 from the liquid medium outlet 64 flows through the second connection pipe 424 to flow into the utilization-side equipment 410 .
- the heat exchange unit 100 is a unit that exchanges heat between a liquid medium sent to the utilization-side equipment 410 and a refrigerant, to perform at least one of cooling and heating of the liquid medium.
- the heat exchange unit 100 of one or more embodiments is a unit that exchanges heat between the liquid medium sent to the utilization-side equipment 410 and the refrigerant, to perform both cooling and heating of the liquid medium.
- the heat source unit 300 need not have the flow path switching mechanism 332 . Further, when the heat exchange unit 100 is a unit intended only for heating the liquid medium, in particular, in a case of not performing a reverse cycle defrost operation for supplying the refrigerant discharged from the compressor 330 to the heat-source-side heat exchanger 340 to remove frost attached to the heat-source-side heat exchanger 340 , the heat source unit 300 need not have the flow path switching mechanism 332 described above.
- the heat exchange unit 100 mainly includes the casing 90 , a drain pan 80 , the utilization-side heat exchanger 10 , a first expansion mechanism 20 , the pump 60 , a gas detection sensor 70 , and an electric component box 92 (see FIGS. 4 to 7 ).
- the heat exchange unit 100 has the first expansion mechanisms 20 of the same number as the number of the heat source units 300 (the same number as the number of the refrigerant circuits 50 including the heat source unit 300 and the heat exchange unit 100 ). In one or more embodiments, the heat exchange unit 100 has four first expansion mechanisms 20 .
- the heat exchange unit 100 of one or more embodiments has two utilization-side heat exchangers 10 (the first heat exchanger 10 a and the second heat exchanger 10 b ) connected in series in the liquid medium circuit 400 .
- the number of utilization-side heat exchangers 10 is an example, and is not limited to two.
- the heat exchange unit 100 may have the utilization-side heat exchangers 10 of the same number (here, four) as the number of the heat source units 300 connected in series in the liquid medium circuit 400 .
- the heat exchange unit 100 may have only one piece of utilization-side heat exchanger 10 , the utilization-side heat exchanger 10 may be connected to all the (here, four) heat source units 300 , and the refrigerant circuits 50 of the same number as the number of the heat source units 300 may be configured. Further, the heat exchange unit 100 may have a plurality of utilization-side heat exchangers 10 connected in parallel in the liquid medium circuit 400 .
- the heat exchange unit 100 of one or more embodiments has one pump 60 .
- the heat exchange unit 100 may have a plurality of pumps 60 connected in series or in parallel in the liquid medium circuit 400 .
- the casing 90 accommodates various components and various devices of the heat exchange unit 100 , including the drain pan 80 , the utilization-side heat exchanger 10 , the first expansion mechanism 20 , the pump 60 , the gas detection sensor 70 , and the electric component box 92 .
- a top surface and side surfaces of the heat exchange unit 100 are surrounded by a top panel and side plates (see FIG. 1 ).
- the drain pan 80 is arranged in a lower part of the casing 90 (see FIG. 6 ). Above the drain pan 80 , the utilization-side heat exchanger 10 and the pump 60 are arranged (see FIG. 6 ).
- the first expansion mechanism 20 is arranged near an upper end of the utilization-side heat exchanger 10 , in front of the utilization-side heat exchanger 10 (see FIG. 6 ).
- the electric component box 92 is arranged at an upper front face side of the casing 90 (see FIG. 7 ).
- the electric component box 92 is arranged above the utilization-side heat exchanger 10 and the pump 60 (see FIG. 6 ).
- an opening 91 a for maintenance is provided (see FIG. 6 ). Further, on a back face of the casing 90 , an opening 91 b for maintenance is provided (see FIG. 9 ).
- the openings 91 a and 91 b of the casing 90 are closed by side plates of the casing 90 normally, that is, during operation of the heat load processing system 1 . By removing the side plates of the casing 90 provided on the openings 91 a and 91 b , components and devices inside the casing 90 can be maintained or replaced.
- liquid-side connecting ports 100 a and four gas-side connecting ports 100 b of the heat exchange unit 100 are provided.
- the liquid-refrigerant connection pipe 52 is connected (see FIG. 2 ).
- the gas-refrigerant connection pipe 54 is connected (see FIG. 2 ).
- the liquid medium inlet 62 and the liquid medium outlet 64 of the heat exchange unit 100 are provided (see FIGS. 5 and 7 ).
- the first connection pipe 422 is connected (see FIG. 2 ).
- the second connection pipe 424 is connected (see FIG. 2 ).
- positions of the liquid-side connecting port 100 a , the gas-side connecting port 100 b , the liquid medium inlet 62 , and the liquid medium outlet 64 are not limited to the positions drawn in the figure, and may be changed as appropriate.
- the drain pan 80 will be described with reference to FIGS. 5 to 10 .
- FIG. 8 is a schematic plan view of the drain pan 80 .
- FIG. 9 is a schematic rear view of a part of the casing 90 (near the drain pan 80 ) and the drain pan of FIG. 8 .
- FIG. 10 is a schematic right side view of the drain pan 80 .
- the drain pan 80 is arranged in a lower part of the casing 90 .
- the drain pan 80 is arranged in a lowermost part of the casing 90 .
- the drain pan 80 is arranged below the utilization-side heat exchanger 10 .
- the drain pan 80 is arranged below the pump 60 .
- the drain pan 80 receives condensation water generated on the utilization-side heat exchanger 10 , the pump 60 , pipes through which the liquid medium and the refrigerant flow, and the like.
- the drain pan 80 may have a function as a bottom plate of the casing 90 .
- the drain pan 80 may be arranged lower than: at least a part of the refrigerant pipe 57 described later; at least a part of the in-heat-exchange-unit first liquid medium pipe 66 , the in-heat-exchange-unit connection pipe 67 , and the in-heat-exchange-unit second liquid medium pipe 68 ; the utilization-side heat exchanger 10 ; and the pump 60 .
- the drain pan 80 may be arranged so as to surround most of a lower part of the heat exchange unit 100 . For example, in top view, the drain pan 80 covers 80% or more of an area of the heat exchange unit 100 (a bottom area of the casing 90 ).
- the drain pan 80 has a bottom plate 82 and a side wall 84 .
- the bottom plate 82 has a substantially rectangular shape in plan view (see FIGS. 8 to 10 ).
- the side wall 84 extends upward from an outer peripheral edge of the bottom plate 82 (see FIGS. 9 and 10 ).
- a height from the bottom plate 82 to the upper end part 84 a of the side wall 84 is about 80 mm at a highest part. That is, a height from an outer peripheral edge on a rear side of the bottom plate 82 to the upper end part 84 a of the side wall 84 is about 80 mm.
- a space formed above the bottom plate 82 of the drain pan 80 and below an upper end part 84 a of the side wall 84 of the drain pan 80 is referred to here as an internal space Si of the drain pan 80 .
- the internal space Si of the drain pan 80 is a space in which the bottom plate 82 and the side wall 84 surround a lower part and a side surface, and an upper part is open.
- the internal space Si of the drain pan 80 is a space surrounded by the bottom plate 82 , the side wall 84 , and a virtual plane passing through the upper end part 84 a of the side wall 84 .
- Condensation water having fallen into the internal space Si of the drain pan 80 is once received by the internal space Si, and discharged from a drain port provided in the drain pan 80 .
- the drain port is an opening to discharge water in the internal space Si of the drain pan 80 .
- the drain port is provided on at least one of the bottom plate 82 and the side wall 84 of the drain pan 80 .
- a drain pipe 86 is attached to the side wall 84 arranged on a rear side of the drain pan 80 so as to communicate with the internal space Si of the drain pan 80 , and an end part of the drain pipe 86 on the internal space Si side functions as a drain port 86 a (see FIG. 8 ).
- the drain port 86 a is provided in a center of the side wall 84 arranged on the rear side of the drain pan 80 .
- the drain pipe 86 is attached to a center of the side wall 84 arranged on the rear side of the drain pan 80 .
- the drain pipe 86 is attached to a lower part of the side wall 84 arranged on the rear side of the drain pan 80 (see FIG. 9 ).
- the drain pan 80 is provided with only one drain port, but the configuration is not limited to this, and drain ports may be provided at a plurality of places. Further, the drain port need not be formed by a pipe fixed to the bottom plate 82 or the side wall 84 of the drain pan 80 , but the drain port may be provided by simply forming a hole in the bottom plate 82 or the side wall 84 of the drain pan 80 .
- the bottom plate 82 of the drain pan 80 has an inclined part 82 a that is inclined with respect to a horizontal plane.
- the entire bottom plate 82 is inclined with respect to the horizontal plane, and the entire bottom plate 82 functions as the inclined part 82 a .
- the inclined part 82 a is inclined so as to be lowered from a front side to a rear side, and has an upper end 82 aa on the front side and a lower end 82 ab on the rear side (see FIG. 10 ).
- the bottom plate 82 is lowered toward the side wall 84 arranged on the rear side of the drain pan 80 provided with the drain port 86 a , and water is easily discharged from the internal space Si of the drain pan 80 through the drain port 86 a.
- the bottom plate 82 of the drain pan 80 need not be entirely inclined with respect to the horizontal plane as in the above-described embodiments. That is, the bottom plate 82 may have the inclined part 82 a only partially. For example, in the bottom plate 82 of the drain pan 80 , a region where condensation water is unlikely to fall need not be provided with an inclination.
- the utilization-side heat exchanger 10 includes the first heat exchanger 10 a and the second heat exchanger 10 b.
- first heat exchanger 10 a and the second heat exchanger 10 b will be described as a description of the utilization-side heat exchanger 10 without distinguishing as the first heat exchanger 10 a or the second heat exchanger 10 b.
- the utilization-side heat exchanger 10 exchanges heat between the refrigerant and the liquid medium.
- the utilization-side heat exchanger 10 is a plate-type heat exchanger.
- a type of the utilization-side heat exchanger 10 is not limited to the plate-type heat exchanger, and it is sufficient to appropriately select a heat exchanger of a type that can be used as a heat exchanger between the refrigerant and the liquid medium.
- the in-heat-exchange-unit connection pipe 67 is a pipe that connects a liquid medium flow path (not illustrated) in the first heat exchanger 10 a with a liquid medium flow path in the second heat exchanger 10 b.
- the liquid medium passes through the first connection pipe 422 and the in-heat-exchange-unit first liquid medium pipe 66 to flow into the first heat exchanger 10 a , and passes through the liquid medium flow path (not illustrated) in the first heat exchanger 10 a to flow out to the in-heat-exchange-unit connection pipe 67 .
- the liquid medium having flowed out from the first heat exchanger 10 a to the in-heat-exchange-unit connection pipe 67 passes through the in-heat-exchange-unit connection pipe 67 to flow into the second heat exchanger 10 b .
- the liquid medium having flowed into the second heat exchanger 10 b passes through the liquid medium flow path (not illustrated) in the second heat exchanger 10 b , and further passes through the in-heat-exchange-unit second liquid medium pipe 68 and the second connection pipe 424 , to be sent to the utilization-side equipment 410 .
- each utilization-side heat exchanger 10 When the operating mode of the heat load processing system 1 is in the cooling mode, to each utilization-side heat exchanger 10 , the refrigerant flows from the in-heat-exchange-unit liquid-side pipe 56 into a refrigerant flow path (not illustrated) in each utilization-side heat exchanger 10 .
- the liquid medium flowing through the liquid medium flow path (not illustrated) in each utilization-side heat exchanger 10 is cooled by exchanging heat with the refrigerant flowing through the refrigerant flow path (not illustrated) in each utilization-side heat exchanger 10 .
- each utilization-side heat exchanger 10 flows into the in-heat-exchange-unit gas-side pipe 58 , and passes through the gas-refrigerant connection pipe 54 to flow into the second gas-side pipe 355 of the heat source unit 300 .
- each utilization-side heat exchanger 10 when the operating mode of the heat load processing system 1 is in the heating mode, to each utilization-side heat exchanger 10 , the refrigerant flows from the in-heat-exchange-unit gas-side pipe 58 into the refrigerant flow path (not illustrated) in each utilization-side heat exchanger 10 .
- the liquid medium flowing through the liquid medium flow path (not illustrated) in each utilization-side heat exchanger 10 is heated by exchanging heat with the refrigerant flowing through the refrigerant flow path (not illustrated) in each utilization-side heat exchanger 10 .
- each utilization-side heat exchanger 10 flows into the in-heat-exchange-unit liquid-side pipe 56 , and passes through the liquid-refrigerant connection pipe 52 to flow into the liquid-side pipe 354 of the heat source unit 300 .
- the first expansion mechanism 20 is a mechanism that expands a refrigerant flowing through the in-heat-exchange-unit liquid-side pipe 56 , to adjust a pressure and a flow rate of the refrigerant.
- the first expansion mechanism 20 is an electronic expansion valve whose opening degree is adjustable.
- the electronic expansion valve as the first expansion mechanism 20 is arranged near an upper end of the utilization-side heat exchanger 10 , in front of the utilization-side heat exchanger 10 .
- the first expansion mechanism 20 is not limited to the electronic expansion valve.
- the first expansion mechanism 20 may be a temperature automatic expansion valve having a temperature sensing cylinder, or may be a capillary tube.
- the pump 60 is a pump that sends the liquid medium to the utilization-side equipment 410 .
- the pump 60 is arranged in the in-heat-exchange-unit first liquid medium pipe 66 .
- the pump 60 is, for example, a constant speed centrifugal pump.
- the pump 60 is not limited to the centrifugal pump, and a type of the pump 60 may be appropriately selected.
- the pump 60 may be, for example, a pump having a variable flow rate.
- the pump 60 is arranged upstream of the utilization-side heat exchanger 10 in a flow direction of the liquid medium in the liquid medium circuit 400 , in other words, in the in-heat-exchange-unit first liquid medium pipe 66 .
- the pump 60 may be arranged downstream of the utilization-side heat exchanger 10 in the flow direction of the liquid medium in the liquid medium circuit 400 , in other words, in the in-heat-exchange-unit second liquid medium pipe 68 .
- the gas detection sensor 70 is a sensor that detects the presence or absence of refrigerant gas in the internal space Si of the drain pan 80 .
- the gas detection sensor 70 may have a detection element 72 , and may detect the presence or absence of refrigerant gas at a place where the detection element 72 is arranged.
- the detection element 72 is, for example, a semiconductor-type sensor element. Electrical conductivity of the semiconductor-type detection element changes depending on a state where no refrigerant gas is present in the surroundings or a state where refrigerant gas is present.
- the gas detection sensor 70 includes a detection circuit (not illustrated) that is electrically connected to the detection element 72 , and detects the presence or absence of the refrigerant gas by detecting a change in electrical conductivity of the detection element 72 with the detection circuit.
- the detection element 72 is not limited to the semiconductor-type element, and may be any element capable of detecting the refrigerant gas.
- the gas detection sensor 70 may include an infrared light source (not illustrated) and an infrared detection element as the detection element 72 , and may detect the presence or absence of the refrigerant gas by detecting a change in a detection amount of infrared rays of the detection element 72 , which changes depending on the presence or absence of refrigerant gas, with a detection circuit that is electrically connected to the detection element 72 .
- the refrigerant gas has a higher density than air, the refrigerant gas easily moves to a lower position when the refrigerant leaks in the heat exchange unit 100 . Therefore, leaked refrigerant gas tends to accumulate in the internal space Si of the drain pan 80 .
- the detection element 72 of the gas detection sensor 70 may be arranged in the internal space Si of the drain pan 80 located at the lower part in the casing 90 .
- the detection element 72 may be arranged on the lower end 82 ab side of the inclined part 82 a of the bottom plate 82 of the drain pan 80 (in one or more embodiments, a rear end side of the bottom plate 82 ). Further, the detection element 72 may be arranged near the drain port 86 a , which is a discharge port of water from the internal space Si of the drain pan 80 .
- the detection element 72 of the gas detection sensor 70 is arranged on the lower end 82 ab side of the inclined part 82 a in the internal space Si of the drain pan 80 (see FIG. 10 ). Further, the detection element 72 of the gas detection sensor 70 is arranged at a position adjacent to the drain port 86 a provided on the side wall 84 on the rear side of the drain pan 80 (see FIGS. 8 to 10 ). By arranging the detection element 72 at such a position where refrigerant gas is likely to accumulate, highly reliable refrigerant leakage detection is possible.
- the position where the detection element 72 of the gas detection sensor 70 is arranged is an example, and is not limited to the position drawn in FIGS. 8 to 10 .
- the position where the detection element 72 of the gas detection sensor 70 is arranged may be, for example, away from the drain port 86 a , in the vicinity of the side wall 84 on the rear side of the drain pan 80 (on the lower end 82 ab side of the inclined part 82 a ).
- the detection element 72 of the gas detection sensor 70 may be arranged near the place where the possibility of leakage of the refrigerant gas is relatively high, in the internal space Si of the drain pan 80 .
- the detection element 72 of the gas detection sensor 70 may be arranged at a place other than the lower end 82 ab side of the inclined part 82 a (for example, the upper end 82 aa side of the inclined part 82 a ).
- the detection element 72 of the gas detection sensor 70 need not be arranged in the internal space Si of the drain pan 80 .
- the gas detection sensor 70 may use the detection element 72 arranged very close to the upper end part 84 a , at a position higher than the upper end part 84 a of the side wall 84 of the drain pan 80 , to detect the presence or absence of the refrigerant gas in the internal space Si of the drain pan 80 .
- the gas detection sensor 70 may use the detection element 72 arranged at another place outside the internal space Si of the drain pan 80 and where the gas in the internal space Si of the drain pan 80 can be detected, to detect the presence or absence of the refrigerant gas in the internal space Si of the drain pan 80 .
- the place outside the internal space Si of the drain pan 80 and where the gas in the internal space Si of the drain pan 80 can be detected includes an opening on an opposite side of the drain port 86 a of the drain pipe 86 .
- the detection element 72 of the gas detection sensor 70 may be arranged below an electric component that can be an ignition source (see FIGS. 6 and 7 ). By arranging the detection element 72 below the electric component that can be an ignition source, refrigerant leakage is easily detected before the refrigerant gas reaches a height position of the electric component that can be an ignition source from the bottom side of the casing 90 , even if the refrigerant leaks in the heat exchange unit 100 .
- the electric component that can be an ignition source include an electric component that may generate an electric spark.
- the electric components that can be an ignition source include: the electric components 93 such as an electromagnetic switch, a contactor, and a relay accommodated in the electric component box 92 , which will be described later; an electronic expansion valve as an example of the first expansion mechanism 20 ; and the terminal box 61 of the pump 60 .
- the terminal box 61 of the pump 60 is connected with an electric wire 61 a for supply of electric power to a motor 60 a of the pump 60 .
- a heater may be arranged in the heat exchange unit 100 when the heat exchange unit 100 is installed in a cold region. Depending on specifications, the heater can be hot enough to be an ignition source. In one or more embodiments, the electric component that can become hot enough to be an ignition source may also be arranged above the detection element 72 of the gas detection sensor 70 .
- the detection element 72 of the gas detection sensor 70 may be arranged below the liquid-side connecting port 100 a and the gas-side connecting port 100 b of the heat exchange unit 100 , which is where refrigerant is relatively likely to leak (see FIGS. 6 and 7 ).
- the electric component that can be an ignition source may be arranged above the liquid-side connecting port 100 a and the gas-side connecting port 100 b of the heat exchange unit 100 .
- Such an arrangement allows refrigerant leakage to be easily detected before the refrigerant gas reaches a height position of the electric component that can be an ignition source from the bottom side of the casing 90 , even if the refrigerant leaks at the liquid-side connecting port 100 a or the gas-side connecting port 100 b of the heat exchange unit 100 .
- the electric component that can be an ignition source in one or more embodiments: the electric components 93 such as an electromagnetic switch, a contactor, and a relay accommodated in the electric component box 92 ; an electronic expansion valve as an example of the first expansion mechanism 20 ; and the terminal box 61 of the pump 60 ) may be arranged at a position that is 300 mm or more higher than a bottom of the casing 90 (see FIGS. 6 and 7 ).
- the electric component that can be an ignition source at such a height position, the possibility of ignition with the electric component in the casing 90 as the ignition source is reduced even if the refrigerant leaks.
- the detection element 72 of the gas detection sensor 70 may be arranged at the following position.
- an inside of the casing 90 is sectioned into at least a pump arrangement area A 1 where the pump 60 is arranged, and a refrigerant side area A 2 where the refrigerant pipe 57 through which the refrigerant flows or the utilization-side heat exchanger 10 is arranged (see FIGS. 5 and 8 ). That is, in plan view, the pump arrangement area A 1 and the refrigerant side area A 2 exist inside the casing 90 . As shown in FIG. 8 , the detection element 72 of the gas detection sensor 70 may be arranged closer to the refrigerant side area A 2 than the pump arrangement area A 1 .
- the detection element 72 of the gas detection sensor 70 may be arranged in a space near the opening 91 b for maintenance, in the casing 90 .
- the space near the opening 91 b is a space accessible to a worker from the opening 91 b .
- the space near the opening 91 b is a space within hand reach from the opening 91 b (for example, a space within 50 cm from the opening 91 b ).
- An arrangement of the detection element 72 of the gas detection sensor 70 at such a position allows the detection element 72 to be easily replaced and inspected by removing the side plate of the casing 90 that closes the opening 91 b.
- the detection element 72 of the gas detection sensor 70 detects the refrigerant gas, it may be that the detection element 72 is arranged at a position that is less likely to be immersed even if condensation water accumulates in the internal space Si of the drain pan 80 .
- the heat exchange unit 100 may have a float 88 that is arranged in the internal space Si of the drain pan 80 , and the detection element 72 may be attached to an upper surface 88 a or a side surface 88 b of the float 88 .
- the float 88 is a member configured to float on a water surface when condensation water accumulates in the internal space Si of the drain pan 80 .
- the float 88 has a main body 881 , and a swing shaft 882 that is swingably supported by a support part (not illustrated) provided on the side wall 84 of the drain pan 80 or a frame (not illustrated) of the casing 90 (see FIGS. 11A and 11B ).
- the main body 881 is configured to float on water.
- the detection element 72 of the gas detection sensor 70 may be attached to the upper surface 88 a of the float 88 (an upper surface of the main body 881 ) as shown in FIG. 11A , or may be attached to the side surface 88 b (a side surface of the main body 881 ) of the float 88 as shown in FIG. 11B .
- the main body 881 of the float 88 When there is no water in the drain pan 80 , the main body 881 of the float 88 is located at a first position. Although not limited, the main body 881 of the float 88 located at the first position is in contact with the bottom plate 82 of the drain pan 80 , as shown by solid lines in FIGS. 11A and 11B . Whereas, when water accumulates in the drain pan 80 , the main body 881 of the float 88 swings around the swing shaft 882 and floats due to buoyancy as shown by two-dot chain lines in FIGS. 11A and 11B . Such a configuration facilitates suppression of immersion of the detection element 72 of the gas detection sensor 70 , even when condensation water accumulates in the internal space Si of the drain pan 80 . Therefore, even if, for example, the drain pipe 86 is clogged for some reason and water is not discharged from the drain port 86 a , the gas refrigerant can be detected by the gas detection sensor 70 when the refriger
- the heat exchange unit 100 need not have the float 88 .
- the detection element 72 of the gas detection sensor 70 may be directly attached to the side wall 84 of the drain pan 80 or the frame (not illustrated) of the casing 90 .
- the detection element 72 of the gas detection sensor 70 may be arranged at a position that is less likely to be immersed, for example, a position higher than the drain port 86 a in the internal space Si of the drain pan 80 , as shown by reference numeral 72 a in FIG. 9 .
- the electric component box 92 is a case that accommodates various electric components.
- the electric component box 92 accommodates the heat-exchange-unit side control board 95 , a power source terminal block (not illustrated), and the electric components 93 such as an electromagnetic switch, a contactor, and a relay (see FIG. 2 ).
- the electric component 93 need not include all of the electromagnetic switch, the contactor, and the relay, but may include any of the electromagnetic switch, the contactor, and the relay. Note that the electric components accommodated in the electric component box 92 are not limited to those exemplified, and various electric components are accommodated as needed.
- the heat-exchange-unit side control board 95 functions as the control unit 95 a together with the heat-source-side control board 395 of the heat source unit 300 .
- the heat-exchange-unit side control board 95 has various electric circuits, a microcomputer including a CPU and a memory that stores a program executed by the CPU, and the like.
- the control unit 95 a controls an operation of each unit of the heat load processing system 1 .
- the control unit 95 a is electrically connected to various devices of the heat source unit 300 and the heat exchange unit 100 .
- the various devices of the heat source unit 300 and the heat exchange unit 100 connected to the control unit 95 a include: the compressor 330 , the flow path switching mechanism 332 , the second expansion mechanism 344 , and the fan 342 of the heat source unit 300 ; and the first expansion mechanism 20 and the pump 60 of the heat exchange unit 100 .
- the control unit 95 a is communicably connected to various sensors provided to the heat source unit 300 and the heat exchange unit 100 , and receives measured values from the various sensors (not illustrated).
- the various sensors provided to the heat exchange unit 100 include, but not limited to, for example, a temperature sensor that is provided in the in-heat-exchange-unit liquid-side pipe 56 or the in-heat-exchange-unit gas-side pipe 58 and measures a temperature of the refrigerant, a pressure sensor provided in the in-heat-exchange-unit liquid-side pipe 56 , a temperature sensor provided in the in-heat-exchange-unit first liquid medium pipe 66 , the in-heat-exchange-unit connection pipe 67 , and the in-heat-exchange-unit second liquid medium pipe 68 and measures a temperature of the liquid medium, and the like.
- the various sensors provided to the heat source unit 300 include, but not limited to, for example, a temperature sensor that is provided in the suction pipe 351 and measures a suction temperature, a temperature sensor that is provided in the discharge pipe 352 and measures a discharge temperature, and a pressure sensor that is provided in the discharge pipe 352 and measures a discharge pressure.
- the control unit 95 a is communicably connected to the gas detection sensor 70 of the heat source unit 300 .
- the control unit 95 a controls an operation of various devices of the heat source unit 300 and the heat exchange unit 100 in response to an operation or stop command given from an operation device (not illustrated). Further, the control unit 95 a controls a state of the flow path switching mechanism 332 of the heat source unit 300 in accordance with an operating mode (the cooling mode or the heating mode) of the heat load processing system 1 . In addition, the control unit 95 a controls an operation of various devices of the heat source unit 300 and the heat exchange unit 100 such that a liquid medium is cooled or heated to reach a predetermined target temperature and flows out from the liquid medium outlet 64 of the heat exchange unit 100 . Note that an operating principle of a vapor compression refrigerator is generally well known, and thus a description thereof is omitted here. In addition, when the gas detection sensor 70 detects leakage of refrigerant gas, the control unit 95 a controls various devices such that various devices of the heat source unit 300 and the heat exchange unit 100 perform a predetermined operation at a time of leakage.
- the heat exchange unit 100 of the above-described embodiments exchanges heat between a liquid medium sent to utilization-side equipment 410 and the refrigerant, to perform at least one of cooling and heating of the liquid medium.
- the heat exchange unit 100 includes the utilization-side heat exchanger 10 as an example of a heat exchanger, the casing 90 , the drain pan 80 , and the gas detection sensor 70 .
- the gas detection sensor 70 is an example of a first gas detection sensor.
- the utilization-side heat exchanger 10 exchanges heat between the flammable refrigerant and the liquid medium.
- the casing 90 accommodates the utilization-side heat exchanger 10 .
- the drain pan 80 is arranged below the utilization-side heat exchanger 10 , in a lower part of the casing 90 .
- the drain pan 80 has the bottom plate 82 and the side wall 84 extending upward from the bottom plate 82 .
- the gas detection sensor 70 detects the presence or absence of refrigerant gas in the internal space Si of the drain pan 80 , the internal space Si being located above the bottom plate 82 of the drain pan 80 and below the upper end part of the side wall 84 of the drain pan 80 .
- the refrigerant gas is usually heavier than air. Therefore, when the refrigerant leaks, the leaked refrigerant gas moves downward. Therefore, in this heat exchange unit 100 , leaked refrigerant gas tends to accumulate in the drain pan 80 that is arranged in the lower part of the casing 90 and receives dew condensation water generated on the pipe, the heat exchanger, and the like.
- the gas detection sensor 70 may have, as an example of a first detection element, the detection element 72 that is arranged in the internal space Si of the drain pan 80 , and may detect the presence or absence of the refrigerant gas at a place where the detection element 72 is arranged.
- the bottom plate 82 of the drain pan 80 has the inclined part 82 a that is inclined with respect to a horizontal plane.
- the detection element 72 is arranged on a lower end side of the inclined part 82 a.
- the detection element of the gas detection sensor 70 is arranged on the lower end side of the inclined part 82 a where the refrigerant gas tends to accumulate, highly reliable refrigerant leakage detection is possible.
- At least one of the bottom plate 82 or the side wall 84 of the drain pan 80 is provided with the drain port 86 a for discharge of water in the internal space Si of the drain pan 80 .
- the detection element 72 is provided near (e.g., adjacent to) the drain port 86 a.
- the detection element 72 of the gas detection sensor 70 is arranged in a position where water is easily discharged, in other words, arranged near the drain port 86 a of the drain pan 80 where water (fluid) easily flows, highly reliable refrigerant leakage detection is possible.
- the heat exchange unit 100 of the above-described embodiments includes the float 88 arranged in the internal space Si of the drain pan 80 .
- the detection element 72 is attached to the upper surface 88 a or the side surface 88 b of the float 88 .
- the detection element 72 of the gas detection sensor 70 is attached to the upper surface 88 a or the side surface 88 b of the float 88 , it is possible to detect refrigerant leakage even when water accumulates in the drain pan 80 .
- the casing 90 is formed with the opening 91 b for maintenance.
- the detection element 72 is arranged in a space near (e.g., adjacent to) the opening 91 b.
- the detection element 72 of the gas detection sensor 70 is arranged in the space near the opening 91 b for maintenance, the detection element 72 of the gas detection sensor 70 can be easily inspected or replaced.
- the heat exchange unit 100 of the above-described embodiments includes the pump 60 .
- the pump 60 is arranged inside the casing 90 .
- the pump 60 sends a liquid medium to the utilization-side equipment 410 .
- An inside of the casing 90 is sectioned into at least the pump arrangement area A 1 and the refrigerant side area A 2 in plan view.
- the pump arrangement area A 1 the pump 60 is arranged.
- the refrigerant pipe 57 through which the refrigerant flows or the utilization-side heat exchanger 10 is arranged.
- the detection element 72 is arranged closer to the refrigerant side area A 2 than the pump arrangement area A 1 in plan view.
- the detection element 72 of the gas detection sensor 70 is arranged, inside the casing 90 , relatively close to the refrigerant pipe 57 through which the refrigerant flows and the utilization-side heat exchanger 10 , highly reliable refrigerant leakage detection is possible.
- the heat exchange unit 100 of the above-described embodiments includes the pump 60 , but the configuration is not limited to this.
- the pump 60 may be installed outside the casing 90 separately from the heat exchange unit 100 .
- the heat exchange unit 100 may further have an auxiliary gas detection sensor 270 having a detection element 272 arranged outside the casing 90 (see FIG. 12 ), in addition to the gas detection sensor 70 having the detection element 72 arranged in the internal space Si of the drain pan 80 .
- the auxiliary gas detection sensor 270 is a sensor that detects the presence or absence of refrigerant gas at a place where the detection element 272 is arranged.
- the auxiliary gas detection sensor 270 is similar to the gas detection sensor 70 except for the installation place of the detection element 272 .
- the auxiliary gas detection sensor 270 can detect refrigerant gas even if the refrigerant gas flows out of the casing 90 , which enhances safety.
- the detection element 272 of the auxiliary gas detection sensor 270 may be arranged near a floor surface FL of a unit installation space (for example, the machine room R) where the heat exchange unit 100 is installed.
- the detection element 272 may be arranged at a position lower than a height position of 300 mm above the floor surface FL of the machine room R.
- the heat exchange unit 100 may be installed on a foundation (a stand) 2 provided on the floor surface FL in the machine room R (see FIG. 12 ). In such a case, the detection element 272 of the auxiliary gas detection sensor 270 may be arranged near the floor surface FL of the machine room R.
- the detection element 272 of the auxiliary gas detection sensor 270 may be arranged at a height position up to 300 mm above the floor surface FL of the machine room R. In this case, the detection element 272 of the auxiliary gas detection sensor 270 may be arranged at a position lower than the bottom of the casing 90 of the heat exchange unit 100 .
- a liquid medium cooled or heated by the heat exchange unit 100 circulates in the liquid medium circuit 400 , but the configuration is not limited to this.
- the liquid medium sent to the utilization-side equipment 410 for example, a tank
- the utilization-side equipment 410 may be used as it is without circulating in the liquid medium circuit 400 .
- a heat exchange unit 200 according to one or more embodiments and a heat load processing system 201 including the heat exchange unit 100 will be described with reference to the drawings.
- FIG. 13 is a perspective view of the heat exchange unit 200 .
- FIG. 14 is a schematic configuration diagram of the heat load processing system 201 including the heat exchange unit 200 . Note that the heat exchange unit 200 has three systems of an identical refrigerant circuit 150 , but only one system of the refrigerant circuit 150 is drawn in FIG. 14 .
- FIG. 15 is a schematic plan view of a lower part inside a casing 190 of the heat exchange unit 200 .
- FIG. 16 is a schematic front view of the heat exchange unit 200 with a side plate of the casing 190 removed.
- FIG. 17 is a schematic right side view of the heat exchange unit 200 with a side plate of the casing 190 removed.
- FIG. 18 is a schematic rear view of a part of the casing 190 of the heat exchange unit 200 (near a drain pan 80 ) and the drain pan 80 .
- the refrigerant is cooled or heated by exchanging heat between air around the heat source unit 300 and the refrigerant, in the heat-source-side heat exchanger 340 .
- a refrigerant is cooled or heated by heat exchange between the refrigerant and a heat-source-side liquid medium flowing through a heat-source-side liquid medium circuit 500 .
- the heat load processing system 201 is a system in which the refrigerant is cooled by cooling water flowing through the heat-source-side liquid medium circuit 500 , and a liquid medium sent to utilization-side equipment 410 is cooled by the refrigerant in the heat exchange unit 200 .
- the heat load processing system 201 may be, for example, a system in which the refrigerant is heated by a heat-source-side liquid medium (for example, waste warm water) flowing through the heat-source-side liquid medium circuit 500 , and a liquid medium sent to the utilization-side equipment 410 is heated by the refrigerant in the heat exchange unit 200 .
- a heat-source-side liquid medium for example, waste warm water
- the heat load processing system 201 may be a system capable of execution by switching between: a cooling mode in which the refrigerant is cooled by a relatively low temperature heat-source-side liquid medium flowing through the heat-source-side liquid medium circuit 500 , and a liquid medium sent to the utilization-side equipment 410 is cooled by the refrigerant in the heat exchange unit 200 ; and a heating mode in which the refrigerant is heated by a relatively high temperature heat-source-side liquid medium flowing through the heat-source-side liquid medium circuit 500 , and a liquid medium sent to the utilization-side equipment 410 is heated by the refrigerant in the heat exchange unit 200 .
- the liquid medium flowing through the heat-source-side liquid medium circuit 500 is referred to as a heat-source-side liquid medium
- the liquid medium sent to the utilization-side equipment 410 is simply referred to as a liquid medium.
- the refrigerant circuit 50 is formed by the heat source unit 300 and the heat exchange unit 100 .
- the heat exchange unit 200 has the entire refrigerant circuit 150 .
- one heat exchange unit 200 has three systems of the refrigerant circuit 150 .
- the heat exchange unit 200 may have one or two systems of refrigerant circuit 150 , or four or more systems of refrigerant circuit 150 .
- the heat load processing system 201 mainly includes the heat exchange unit 200 , the heat-source-side liquid medium circuit 500 , and the utilization-side equipment 410 .
- the heat exchange unit 200 is a device that exchanges heat between a liquid medium sent to the utilization-side equipment 410 and a refrigerant, to perform at least one of cooling and heating of the liquid medium.
- the liquid medium cooled or heated by the liquid refrigerant in the heat exchange unit 200 is sent to the utilization-side equipment 410 .
- the exemplified heat exchange unit 200 drawn in FIG. 14 is a unit that only cools the liquid medium by exchanging heat between the liquid medium and the refrigerant.
- the configuration is not limited to this, and the heat exchange unit 200 may be a unit that only heats the liquid medium by exchanging heat between the liquid medium and the refrigerant.
- the heat exchange unit 200 may be, for example, a device capable of both cooling and heating of the liquid medium by exchanging heat between the liquid medium and the refrigerant.
- liquid medium and the refrigerant used in one or more embodiments are similar to the liquid medium and the refrigerant described in the above-described embodiments. The description is omitted here.
- the heat-source-side liquid medium used in one or more embodiments is, for example, water or brine.
- the heat-source-side liquid medium circuit 500 is a liquid medium circuit in which the heat-source-side liquid medium that cools the refrigerant in the heat exchange unit 200 circulates.
- the heat-source-side liquid medium circuit 500 mainly includes heat source equipment 510 and a heat-source-side pump 520 .
- the heat source equipment 510 is equipment to cool the heat-source-side liquid medium.
- the heat source equipment 510 is a cooling tower.
- the cooling tower may be an open type that directly cools the heat-source-side heat medium, or may be a closed type that indirectly cools the heat-source-side heat medium.
- a type of the heat-source-side liquid medium may be appropriately determined in accordance with a type of the cooling tower and the like.
- An installation place is not limited, but the heat source equipment 510 is installed, for example, on a rooftop or a space around a building, or the like.
- the heat-source-side pump 520 is a pump that sends the heat-source-side liquid medium cooled by the heat source equipment 510 , to the heat exchange unit 200 .
- the heat-source-side pump 520 is, for example, a constant speed centrifugal pump.
- the heat-source-side pump 520 is not limited to the centrifugal pump, and a type of the heat-source-side pump 520 may be appropriately selected.
- the heat-source-side pump 520 may be, for example, a pump having a variable flow rate.
- an installation place is not limited, the heat-source-side pump 520 is installed in a same machine room R as the heat exchange unit 200 , for example.
- the utilization-side equipment 410 is similar to the utilization-side equipment 410 in the heat load processing system 1 of the above-described embodiments. However, in one or more embodiments, the utilization-side equipment 410 is equipment that uses a liquid medium cooled by the refrigerant. For example, although not limited, the utilization-side equipment 410 is an air handling unit or a fan coil unit used only for cooling. Note that the utilization-side equipment 410 is not limited to the equipment that uses the liquid medium cooled by the refrigerant. When the heat load processing system 201 is configured so that the liquid medium is heated by the refrigerant in the heat exchange unit 200 , the utilization-side equipment 410 may be, for example, equipment that uses the liquid medium heated by the refrigerant.
- FIG. 14 shows only one piece of utilization-side equipment 410 .
- the heat load processing system 201 may include a plurality of pieces of the utilization-side equipment.
- types of the pieces of the utilization-side equipment may all be the same, or the pieces of the utilization-side equipment may include a plurality of types of equipment.
- the heat exchange unit 200 will be described in detail.
- a liquid medium circuit 400 A in one or more embodiments is similar to the liquid medium circuit 400 of the above-described embodiments except for the fact that a pump 160 (a device similar to the pump 60 of the above-described embodiments) is arranged outside of the heat exchange unit 200 (a first connection pipe 422 ), and for a configuration of a liquid medium pipe in the heat exchange unit 200 .
- a pump 160 a device similar to the pump 60 of the above-described embodiments
- a first connection pipe 422 a first connection pipe 422
- the liquid medium pipe in the heat exchange unit 200 will be described, and detailed description of other liquid medium circuit 400 A will be omitted.
- the heat exchange unit 200 will be described with reference to FIGS. 13 to 18 .
- the heat exchange unit 200 has three systems of the refrigerant circuit 150 .
- FIG. 14 only one system of the three systems of the refrigerant circuit 150 is drawn. Since other refrigerant circuits 150 are similar to the refrigerant circuit 150 described here, a description thereof will be omitted here.
- the heat exchange unit 200 mainly includes a compressor 130 , a heat-source-side heat exchanger 140 , an expansion mechanism 120 , a utilization-side heat exchanger 110 , the casing 190 , the drain pan 80 , a gas detection sensor 70 , and an electric component box 192 .
- the compressor 130 , the heat-source-side heat exchanger 140 , the expansion mechanism 120 , and the utilization-side heat exchanger 110 are connected by a refrigerant pipe 151 , to form the refrigerant circuit 150 .
- the refrigerant pipe 151 includes a first refrigerant pipe 151 a that connects a discharge side of the compressor 130 and a gas side of the heat-source-side heat exchanger 140 .
- the refrigerant pipe 151 includes a second refrigerant pipe 151 b that connects a liquid side of the heat-source-side heat exchanger 140 and a liquid side of the utilization-side heat exchanger 110 .
- the expansion mechanism 120 is arranged in the second refrigerant pipe 151 b .
- the refrigerant pipe 151 includes a third refrigerant pipe 151 c that connects a gas side of the utilization-side heat exchanger 110 and a suction side of the compressor 130 .
- an accumulator (not illustrated) may be arranged.
- the heat exchange unit 200 is a device that cools the liquid medium with the refrigerant as described above.
- the refrigerant circuit 150 is provided with a flow path switching mechanism, similarly to the refrigerant circuit 50 of the above-described embodiments.
- the compressor 130 suctions a low pressure refrigerant in a refrigeration cycle returning from the utilization-side heat exchanger 110 , compresses the refrigerant with a compression mechanism (not illustrated), and sends a high-pressure refrigerant in the refrigeration cycle after compression, to the heat-source-side heat exchanger 140 .
- the compressor 130 is, for example, a scroll-type compressor.
- a type of the compressor 130 is not limited to the scroll type, and the compressor may be, for example, a screw type, a rotary type, or the like.
- the compressor 130 is, for example, a compressor having a variable capacity, but may be, for example, a compressor having a constant capacity.
- the heat-source-side heat exchanger 140 is a heat exchanger that exchanges heat between a heat-source-side liquid medium flowing in the heat-source-side heat exchanger 140 and a refrigerant flowing in the heat-source-side heat exchanger 140 .
- the heat-source-side heat exchanger 340 is, for example, a double-tube heat exchanger.
- a type of the heat-source-side heat exchanger 340 is not limited to the double-tube heat exchanger, and it is sufficient to appropriately select a heat exchanger of a type that can be used as a heat exchanger between the refrigerant and the heat-source-side liquid medium.
- the expansion mechanism 120 is a mechanism that expands a refrigerant flowing through the second refrigerant pipe 151 b , to adjust a pressure and a flow rate of the refrigerant.
- the expansion mechanism 120 is an electronic expansion valve whose opening degree is adjustable.
- the expansion mechanism 120 is not limited to the electronic expansion valve.
- the expansion mechanism 120 may be a temperature automatic expansion valve having a temperature sensing cylinder, or may be a capillary tube.
- the utilization-side heat exchanger 110 exchanges heat between the refrigerant and the liquid medium.
- the utilization-side heat exchanger 110 is a plate-type heat exchanger.
- a type of the utilization-side heat exchanger 110 is not limited to the plate-type heat exchanger, and it is sufficient to appropriately select a heat exchanger of a type that can be used as a heat exchanger between the refrigerant and the liquid medium.
- the utilization-side heat exchanger 110 is connected with the second refrigerant pipe 151 b , the third refrigerant pipe 151 c , a first in-heat-exchange-unit liquid medium pipe 166 , and a second in-heat-exchange-unit liquid medium pipe 168 .
- the first in-heat-exchange-unit liquid medium pipe 166 is a pipe that connects a liquid medium inlet 162 of the heat exchange unit 200 and the utilization-side heat exchanger 110 .
- the second in-heat-exchange-unit liquid medium pipe 168 is a pipe that connects the utilization-side heat exchanger 110 and a liquid medium outlet 164 of the heat exchange unit 200 .
- the liquid medium inlet 162 of the heat exchange unit 200 is connected with the first connection pipe 422 that connects the utilization-side equipment 410 and the liquid medium inlet 162 of the heat exchange unit 200 .
- the liquid medium outlet 164 of the heat exchange unit 200 is connected with a second connection pipe 424 that connects the utilization-side equipment 410 and the liquid medium outlet 164 of the heat exchange unit 200 .
- the refrigerant flows from the second refrigerant pipe 151 b into the utilization-side heat exchanger 110 , and flows through a refrigerant flow path (not illustrated) in the utilization-side heat exchanger 110 to flow out to the third refrigerant pipe 151 c .
- the pump 160 when the pump 160 is operated, the liquid medium having flowed out from the utilization-side equipment 410 flows through the first connection pipe 422 toward the liquid medium inlet 162 of the heat exchange unit 200 .
- the liquid medium having flowed into the heat exchange unit 200 from the liquid medium inlet 162 passes through the first in-heat-exchange-unit liquid medium pipe 166 to flow into the utilization-side heat exchanger 110 .
- the liquid medium passes through a liquid medium flow path (not illustrated) of the utilization-side heat exchanger 110 , the liquid medium is cooled by exchanging heat with the refrigerant flowing through the refrigerant flow path (not illustrated).
- the liquid medium cooled by the utilization-side heat exchanger 110 flows out to the second in-heat-exchange-unit liquid medium pipe 168 , and flows toward the liquid medium outlet 164 .
- the liquid medium having flowed out of the heat exchange unit 200 from the liquid medium outlet 164 flows through the second connection pipe 424 to flow into the utilization-side equipment 410 .
- the casing 190 accommodates various components and various devices of the heat exchange unit 200 , including the compressor 130 , the heat-source-side heat exchanger 140 , the expansion mechanism 120 , the utilization-side heat exchanger 110 , the drain pan 80 , the gas detection sensor 70 , and the electric component box 192 .
- a top surface and side surfaces of the heat exchange unit 200 are surrounded by a top panel and side plates (see FIG. 13 ).
- the drain pan 80 is arranged in a lower part of the casing 190 (see FIG. 18 ).
- the heat-source-side heat exchanger 140 is arranged (see FIG. 18 ).
- the utilization-side heat exchanger 110 is arranged (see FIG. 18 ).
- the utilization-side heat exchanger 110 is arranged above the heat-source-side heat exchanger 140 (see FIG. 18 ).
- the expansion mechanism 120 is arranged above the heat-source-side heat exchanger 140 , in a back face side of the casing 190 (see FIG. 18 ).
- the electric component box 192 is arranged at an upper front face side of the casing 190 (see FIG. 18 ).
- the electric component box 192 is arranged above the heat-source-side heat exchanger 140 (see FIG. 18 ).
- the compressor 130 is arranged above the heat-source-side heat exchanger 140 .
- At least the back face of the casing 190 is provided with an opening 191 b for maintenance (see FIG. 18 ).
- the opening 191 b of the casing 190 is closed by a side plate of the casing 190 normally, that is, during operation of the heat load processing system 201 .
- a heat-source-side liquid medium inlet and a heat-source-side liquid medium outlet (not illustrated) to which a pipe of the heat-source-side liquid medium is connected.
- the liquid medium inlet 162 connected with the first connection pipe 422 and the liquid medium outlet 164 connected with the second connection pipe 424 .
- a connection method is not limited, the first connection pipe 422 and the liquid medium inlet 162 are screwed to be connected.
- the liquid medium outlet 164 and the second connection pipe 424 are screwed to be connected.
- positions of the heat-source-side liquid medium inlet and the heat-source-side liquid medium outlet, and the liquid medium inlet 162 and the liquid medium outlet 164 are not limited to the positions drawn in the figure, and may be changed as appropriate.
- the drain pan 80 is arranged in a lower part of the casing 190 .
- the drain pan 80 is arranged in a lowermost part of the casing 190 .
- the drain pan 80 is arranged below the utilization-side heat exchanger 110 . Further, the drain pan 80 is arranged below the heat-source-side heat exchanger 140 .
- the drain pan 80 receives condensation water generated on the utilization-side heat exchanger 110 , a pipe through which the liquid medium flows, and the like. When the heat exchange unit 200 is installed outdoors, rainwater or the like also flows into the drain pan 80 .
- the drain pan 80 may have a function as a bottom plate of the casing 190 .
- the drain pan 80 may be arranged lower than: at least a part of the first in-heat-exchange-unit liquid medium pipe 166 and the second in-heat-exchange-unit liquid medium pipe 168 ; the refrigerant pipe 151 ; and the utilization-side heat exchanger 110 .
- the drain pan 80 may be arranged so as to surround most of a lower part of the heat exchange unit 200 .
- the drain pan 80 covers 80% or more of an area of the heat exchange unit 200 (a bottom area of the casing 190 ).
- a structure of the drain pan 80 of the heat exchange unit 200 of one or more embodiments is similar to that of the drain pan 80 of the heat exchange unit 100 of the above-described embodiments, and thus a description thereof will be omitted here in order to avoid redundancy.
- the gas detection sensor 70 is a sensor that detects the presence or absence of refrigerant gas in the internal space Si of the drain pan 80 .
- the gas detection sensor 70 may be a sensor that has the detection element 72 , and may detect the presence or absence of refrigerant gas at a place where the detection element 72 is arranged.
- the gas detection sensor 70 is a sensor similar to the gas detection sensor 70 of the above-described embodiments.
- the detection element 72 of the gas detection sensor 70 is arranged in the internal space Si of the drain pan 80 located at the lower part in the casing 190 . Further, similarly to the above-described embodiments, the detection element 72 may be arranged on a lower end 82 ab side of an inclined part 82 a of a bottom plate 82 of the drain pan 80 (in one or more embodiments, a rear end side of the bottom plate 82 ). Further, similarly to the above-described embodiments, the detection element 72 may be arranged near a drain port 86 a , which is a discharge port for water from the internal space Si of the drain pan 80 . By arranging the detection element 72 at such a position where refrigerant gas is likely to accumulate, highly reliable refrigerant leakage detection is possible.
- the position where the detection element 72 of the gas detection sensor 70 is arranged is not limited to a specific position in the internal space Si of the drain pan 80 , similarly to the above-described embodiments.
- the position where the detection element 72 of the gas detection sensor 70 is arranged may be, similarly to the above-described embodiments, a place outside the internal space Si of the drain pan 80 and where the gas in the internal space Si of the drain pan 80 can be detected.
- the detection element 72 of the gas detection sensor 70 may be arranged below the electric component that can be an ignition source.
- the electric component that can be an ignition source include an electric component that may generate an electric spark.
- the electric components that can be an ignition source include: the electric component 93 such as an electromagnetic switch, a contactor, and a relay, and the inverter board 194 for the compressor 130 , which are accommodated in the electric component box 192 ; an electronic expansion valve as an example of the expansion mechanism 120 ; and the terminal box 131 of the compressor 130 .
- the terminal box 131 of the compressor 130 is connected with an electric wire (not illustrated) for supply of electric power to a motor 130 a of the compressor 130 .
- a heater may be arranged in the heat exchange unit 200 when the heat exchange unit 200 is installed in a cold region. Depending on specifications, the heater can be hot enough to be an ignition source. In one or more embodiments, the electric component that can become hot enough to be an ignition source may also be arranged above the detection element 72 of the gas detection sensor 70 .
- the electric component that can be an ignition source in one or more embodiments: the electric components 93 such as an electromagnetic switch, a contactor, and a relay, and the inverter board 194 for the compressor 130 , which are accommodated in the electric component box 192 ; an electronic expansion valve as an example of the expansion mechanism 120 ; and the terminal box 131 of the compressor 130 ) may be arranged at a high position of 300 mm or more from the bottom of the casing 190 (see FIGS. 16 and 17 ).
- the electric component that can be an ignition source at such a height position, the possibility of ignition with the electric component in the casing 190 as the ignition source is reduced even if the refrigerant leaks.
- the detection element 72 of the gas detection sensor 70 may be arranged in a space near (e.g., adjacent to) the opening 191 b for maintenance, in the casing 190 .
- the space near the opening 191 b is a space accessible to a worker from the opening 191 b .
- the space near the opening 191 b may be a space within hand reach from the opening 191 b (for example, a space within 50 cm from the opening 191 b ).
- An arrangement of the detection element 72 of the gas detection sensor 70 at such a position allows the detection element 72 to be easily replaced and inspected by removing the side plate of the casing 190 that closes the opening 191 b.
- the gas detection sensor 70 may have a structure in which the detection element 72 is less likely to be immersed even if condensation water accumulates in the internal space Si of the drain pan 80 .
- the heat exchange unit 200 may have a float 88 arranged in the internal space Si of the drain pan 80 , and the detection element 72 of the gas detection sensor 70 may be attached to an upper surface 88 a of the float 88 or a side surface 88 b of the float 88 .
- the description of the float 88 will be omitted.
- the detection element 72 of the gas detection sensor 70 may be directly attached to the side wall 84 of the drain pan 80 or a frame (not illustrated) of the casing 90 .
- the detection element 72 of the gas detection sensor 70 may be arranged at a position that is less likely to be immersed, for example, a position higher than the drain port 86 a in the internal space Si of the drain pan 80 , as shown by reference numeral 72 a in FIG. 18 .
- the electric component box 192 is a case that accommodates various electric components.
- the electric component box 192 accommodates the heat-exchange-unit side control board 195 , a power source terminal block (not illustrated), the inverter board 194 for the compressor 130 , and the electric components 93 such as an electromagnetic switch, a contactor, and a relay (see FIG. 14 ).
- the electric component 93 need not include all of the electromagnetic switch, the contactor, and the relay, but may include any of the electromagnetic switch, the contactor, and the relay. Note that the electric components accommodated in the electric component box 192 are not limited to those exemplified, and various electric components are accommodated as needed.
- the heat-exchange-unit side control board 195 has various electric circuits, a microcomputer including a CPU and a memory that stores a program executed by the CPU, and the like.
- the heat-exchange-unit side control board 195 controls an operation of each part of the heat exchange unit 200 .
- the heat-exchange-unit side control board 195 is electrically connected to various devices of the heat exchange unit 200 .
- the various devices of the heat exchange unit 200 connected to the heat-exchange-unit side control board 195 include the compressor 130 and the expansion mechanism 120 .
- the heat-exchange-unit side control board 195 may transmit a control signal to the pump 160 , the heat-source-side pump 520 , and the like.
- the heat-exchange-unit side control board 195 is communicably connected to various sensors provided to the heat exchange unit 200 , and receives measured values from the various sensors (not illustrated).
- the various sensors provided to the heat exchange unit 200 include, but not limited to, for example, a temperature sensor that is provided in the first refrigerant pipe 151 a and the third refrigerant pipe 151 c and measures a temperature of a refrigerant, a pressure sensor that is provided in the first refrigerant pipe 151 a and measures a pressure of the refrigerant, a temperature sensor that is provided in the first in-heat-exchange-unit liquid medium pipe 166 and the second in-heat-exchange-unit liquid medium pipe 168 and measures the temperature of the liquid medium, and the like.
- the heat-exchange-unit side control board 195 is communicably connected to the gas detection sensor 70 of the heat exchange unit 200 .
- the heat-exchange-unit side control board 195 controls an operation of various devices of the heat exchange unit 200 and an operation of the pump 160 and the heat-source-side pump 520 , in response to an operation or stop command given from an operation device (not illustrated). Further, the heat-exchange-unit side control board 195 controls an operation of various devices of the heat exchange unit 200 such that the liquid refrigerant is cooled to reach a predetermined target temperature and flows out from the liquid medium outlet 164 of the heat exchange unit 200 .
- an operating principle of a vapor compression refrigerator is generally well known, and thus a description thereof is omitted here.
- the heat-exchange-unit side control board 195 controls devices such that the various devices of the heat exchange unit 200 , the pump 160 , and the heat-source-side pump 520 perform a predetermined operation at a time of leakage.
- the heat exchange unit 200 of the above-described embodiments exchanges heat between the liquid medium sent to the utilization-side equipment 410 and the refrigerant, to perform at least one of cooling and heating of the liquid medium.
- the heat exchange unit 200 includes the utilization-side heat exchanger 110 as an example of a heat exchanger, the casing 190 , the drain pan 80 , and the gas detection sensor 70 as an example of a first gas detection sensor.
- the utilization-side heat exchanger 110 exchanges heat between the flammable refrigerant and the liquid medium.
- the casing 190 accommodates the utilization-side heat exchanger 110 .
- the drain pan 80 is arranged below the utilization-side heat exchanger 110 , in a lower part of the casing 190 .
- the drain pan 80 has the bottom plate 82 and the side wall 84 extending upward from the bottom plate 82 .
- the gas detection sensor 70 detects the presence or absence of refrigerant gas in the internal space Si of the drain pan 80 , the internal space Si being located above the bottom plate 82 of the drain pan 80 and below the upper end part of the side wall 84 of the drain pan 80 .
- the refrigerant gas is usually heavier than air. Therefore, when the refrigerant leaks, the leaked refrigerant gas moves downward. Therefore, in this heat exchange unit 200 , leaked refrigerant gas tends to accumulate in the drain pan 80 that is arranged in the lower part of the casing 190 and receives dew condensation water generated on the pipe, the heat exchanger, and the like.
- the gas detection sensor 70 may have, as an example of a first detection element, the detection element 72 that is arranged in the internal space Si of the drain pan 80 , and detects the presence or absence of the refrigerant gas at a place where the detection element 72 is arranged.
- the bottom plate 82 of the drain pan 80 has the inclined part 82 a that is inclined with respect to a horizontal plane.
- the detection element 72 is arranged on a lower end side of the inclined part 82 a.
- the detection element of the gas detection sensor 70 is arranged on the lower end side of the inclined part 82 a where the refrigerant gas tends to accumulate, highly reliable refrigerant leakage detection is possible.
- At least one of the bottom plate 82 or the side wall 84 of the drain pan 80 is provided with the drain port 86 a for discharge of water in the internal space Si of the drain pan 80 .
- the detection element 72 is provided near (e.g., adjacent to) the drain port 86 a.
- the detection element 72 of the gas detection sensor 70 is arranged near the drain port 86 a of the drain pan 80 that is arranged at a position where water is easily discharged, highly reliable refrigerant leakage detection is possible.
- the heat exchange unit 200 of the above-described embodiments includes the float 88 arranged in the internal space Si of the drain pan 80 .
- the detection element 72 is attached to the upper surface 88 a or the side surface 88 b of the float 88 .
- the detection element 72 of the gas detection sensor 70 is attached to the upper surface 88 a or the side surface 88 b of the float 88 , it is possible to detect refrigerant leakage even when water accumulates in the drain pan 80 .
- the casing 190 is formed with the opening 191 b for maintenance.
- the detection element 72 is arranged in a space near (e.g., adjacent to) the opening 191 b.
- the detection element 72 of the gas detection sensor 70 is arranged in the space near the opening 191 b for maintenance, the detection element 72 of the gas detection sensor 70 can be easily inspected or replaced.
- the heat exchange unit 200 of the above-described embodiments does not have a pump 160 or a heat-source-side pump 520 , but the configuration is not limited thereto.
- the heat exchange unit 200 may have the pump 160 and/or the heat-source-side pump 520 arranged inside the casing 190 .
- the heat exchange unit 200 may further have an auxiliary gas detection sensor having a detection element arranged outside the casing 90 , in addition to the gas detection sensor 70 having the detection element arranged in the internal space Si of the drain pan 80 . Detailed description will be omitted.
- a liquid medium cooled or heated by the heat exchange unit 200 circulates in the liquid medium circuit 400 , but the configuration is not limited to this.
- the liquid medium sent to the utilization-side equipment 410 for example, a tank
- the utilization-side equipment 410 may be used as it is without circulating in the liquid medium circuit 400 .
- the heat-source-side liquid medium that exchanges heat with the refrigerant circulates in the heat-source-side liquid medium circuit 500 , but the configuration is not limited to this.
- the heat-source-side liquid medium may be groundwater or warm wastewater.
- the heat load processing system 201 may not include the heat source equipment 510 , and the heat-source-side liquid medium that has exchanged heat with the refrigerant in the heat-source-side heat exchanger 140 may be drained as it is.
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Abstract
A heat exchange unit performs at least one of a cooling and a heating of a liquid medium that is sent to a utilization side equipment. The heat exchanging unit includes: a heat exchanger that exchanges heat between a flammable refrigerant and the liquid medium; a casing that accommodates the heat exchanger; a drain pan with a bottom plate and a side wall that extends upward from the bottom plate; and a first gas detection sensor that detects presence or absence of a gas of the refrigerant in an internal space of the drain pan. The internal space is a space within the drain pan that is surrounded by the bottom plate, the side wall, and a virtual plane passing through an upper end part of the side wall. The drain pan is disposed below the heat exchanger in a lower part of the casing.
Description
- The present disclosure relates to a heat exchange unit that exchanges heat between a refrigerant and a liquid medium sent to utilization-side equipment, to cool or heat the liquid medium.
- Conventionally, there is known a heat exchange unit that exchanges heat between a refrigerant and a liquid medium sent to utilization-side equipment, to cool or heat the liquid medium. For example, Patent Literature 1 (WO 2014/97440 A) discloses a heat exchange unit that cools brine or the like with a refrigerant in a heat exchanger arranged in a relay device, and sends the cooled brine or the like to utilization-side equipment.
-
- Patent Literature 1: WO 2014/97440 A
- Meanwhile, in this heat exchange unit, a flammable (including mildly flammable) refrigerant may be used in consideration of various characteristics of the refrigerant. However, when a flammable refrigerant is used in the heat exchange unit, there is a possibility of ignition if the refrigerant leaks for some reason.
- Therefore, in the heat exchange unit that uses a flammable refrigerant, highly reliable refrigerant leakage detection is desired.
- A heat exchange unit according to one or more embodiments exchanges heat between a liquid medium sent to utilization-side equipment and a refrigerant that is flammable, to perform at least one of cooling and heating of the liquid medium. The heat exchange unit includes a heat exchanger, a casing, a drain pan, and a first gas detection sensor. The heat exchanger exchanges heat between the refrigerant and the liquid medium. The casing accommodates the heat exchanger. The drain pan is arranged below the heat exchanger, in a lower part of the casing. The drain pan has a bottom plate and a side wall extending upward from the bottom plate. The first gas detection sensor detects the presence or absence of refrigerant gas in an internal space of the drain pan, the internal space being located above the bottom plate of the drain pan and below an upper end part of the side wall of the drain pan.
- The refrigerant gas is usually heavier than air. Therefore, when the refrigerant leaks, the leaked refrigerant gas moves downward. Therefore, in this heat exchange unit, leaked refrigerant gas tends to accumulate in the drain pan that is arranged in the lower part of the casing and receives dew condensation water generated on a pipe, the heat exchanger, and the like.
- Here, highly reliable refrigerant leakage detection is possible by detecting the presence or absence of refrigerant gas in the internal space of the drain pan where leaked refrigerant gas tends to accumulate.
- In one or more embodiments, the first gas detection sensor has a first detection element arranged in the internal space of the drain pan, and detects the presence or absence of refrigerant gas at a place where the first detection element is arranged.
- Here, by arranging the detection element of the first gas detection sensor in the internal space of the drain pan where leaked refrigerant gas tends to accumulate, highly reliable refrigerant leakage detection is possible.
- In one or more embodiments, the bottom plate of the drain pan has an inclined part that is inclined with respect to a horizontal plane. The first detection element is arranged on a lower end side of the inclined part.
- Here, since the detection element of the first gas detection sensor is arranged on the lower end side of the inclined part where the refrigerant gas tends to accumulate, highly reliable refrigerant leakage detection is possible.
- In one or more embodiments, at least one of the bottom plate and the side wall of the drain pan is provided with a drain port for discharge of water in the internal space of the drain pan. The first detection element is provided near the drain port.
- Here, since the detection element of the first gas detection sensor is arranged near the drain port of the drain pan that is arranged at a position where water is easily discharged, highly reliable refrigerant leakage detection is possible.
- In one or more embodiments, a heat exchange unit further includes a float arranged in the internal space of the drain pan. The first detection element is attached to an upper surface or a side surface of the float.
- Here, since the detection element of the first gas detection sensor is attached to the upper surface or the side surface of the float, it is possible to detect refrigerant leakage even when water accumulates in the drain pan.
- In one or more embodiments, a heat exchange unit further includes a second gas detection sensor. The second gas detection sensor has a second detection element arranged outside the casing. The second gas detection sensor detects the presence or absence of refrigerant gas at a place where the second detection element is arranged.
- Here, even if the refrigerant gas flows out of the casing, refrigerant gas can be detected by the second gas detection sensor provided separately, which enhances safety.
- In one or more embodiments, the casing is formed with an opening for maintenance. The first detection element is arranged in a space near the opening.
- Here, since the detection element of the first gas detection sensor is arranged in the space near the opening for maintenance, the detection element of the first gas detection sensor can be easily inspected and replaced.
- In one or more embodiments, a heat exchange unit further includes a pump. The pump is arranged inside the casing. The pump sends the liquid medium to the utilization-side equipment. An inside of the casing is sectioned into at least a pump arrangement area and a refrigerant side area in plan view. In the pump arrangement area, the pump is arranged. In the refrigerant side area, a refrigerant pipe through which the refrigerant flows or the heat exchanger is arranged. The first detection element is arranged closer to the refrigerant side area than the pump arrangement area in plan view.
- Here, since the detection element of the first gas detection sensor is arranged, inside the casing, relatively close to the heat exchanger or the refrigerant pipe through which the refrigerant flows, highly reliable refrigerant leakage detection is possible.
-
FIG. 1 is a perspective view of a heat exchange unit according to one or more embodiments. -
FIG. 2 is a schematic configuration diagram of a heat load processing system including the heat exchange unit ofFIG. 1 . -
FIG. 3 is a schematic plan view of a machine room that is an installation place of the heat exchange unit ofFIG. 1 . -
FIG. 4 is a schematic front view of the heat exchange unit ofFIG. 1 . -
FIG. 5 is a schematic plan view of a lower part inside a casing of the heat exchange unit ofFIG. 1 . -
FIG. 6 is a schematic front view of the heat exchange unit ofFIG. 1 with a side plate of the casing removed. -
FIG. 7 is a schematic right side view of the heat exchange unit ofFIG. 1 with a side plate of the casing removed. -
FIG. 8 is a schematic plan view of a drain pan of the heat exchange unit ofFIG. 1 . -
FIG. 9 is a schematic rear view of a part of the casing of the heat exchange unit ofFIG. 1 and the drain pan ofFIG. 8 . -
FIG. 10 is a schematic right side view of the drain pan ofFIG. 8 . -
FIG. 11A is view obtained by schematically drawing an example of a float installed in an internal space of the drain pan ofFIG. 8 . -
FIG. 11B is view obtained by schematically drawing another example of the float installed in the internal space of the drain pan ofFIG. 8 . -
FIG. 12 is a schematic front view of a heat exchange unit of Modified example 1B. -
FIG. 13 is a perspective view of a heat exchange unit according to one or more embodiments. -
FIG. 14 is a schematic configuration diagram of a heat load processing system including the heat exchange unit ofFIG. 13 . -
FIG. 15 is a schematic plan view of a lower part inside a casing of the heat exchange unit ofFIG. 13 . -
FIG. 16 is a schematic front view of the heat exchange unit ofFIG. 13 with a side plate of the casing removed. -
FIG. 17 is a schematic right side view of the heat exchange unit ofFIG. 13 with a side plate of the casing removed. -
FIG. 18 is a schematic rear view of a part of the casing of the heat exchange unit ofFIG. 12 and a drain pan of the heat exchange unit ofFIG. 12 . -
FIG. 19 is a specific example of a refrigerant used in the heat exchange units of one or more embodiments. - Hereinafter, embodiments of a heat exchange unit will be described.
- A
heat exchange unit 100 according to one or more embodiments and a heat load processing system 1 including theheat exchange unit 100 will be described with reference to the drawings. -
FIG. 1 is a perspective view of theheat exchange unit 100.FIG. 2 is a schematic configuration diagram of the heat load processing system 1 including theheat exchange unit 100. Note that, inFIG. 2 , an internal configuration is drawn only for one of fourheat source units 300, and drawing of an internal configuration of the other three is omitted.FIG. 3 is a schematic plan view of a machine room R where theheat exchange unit 100 is installed.FIG. 4 is a schematic front view of theheat exchange unit 100.FIG. 5 is a schematic plan view of a lower part inside acasing 90 of theheat exchange unit 100.FIG. 6 is a schematic front view of theheat exchange unit 100 with a side plate of thecasing 90 removed.FIG. 7 is a schematic right side view of theheat exchange unit 100 with a side plate of thecasing 90 removed. - Note that, in the following description, expressions indicating directions such as “upper”, “lower”, “left”, “right”, “front (front face)”, and “rear (back face)” may be used. Unless otherwise specified, these directions are indicated by arrows in figures.
- The heat load processing system 1 mainly includes the
heat exchange unit 100, theheat source unit 300, and utilization-side equipment 410. - The
heat exchange unit 100 is a unit that exchanges heat between a liquid medium and a refrigerant, to perform at least one of cooling and heating of the liquid medium. In particular, theheat exchange unit 100 of one or more embodiments performs both cooling and heating of the liquid medium by exchanging heat between the liquid medium and the refrigerant. The liquid medium cooled or heated by a liquid refrigerant in theheat exchange unit 100 is sent to the utilization-side equipment 410. - Note that the liquid medium used in one or more embodiments is, for example, a heat medium such as water or brine. The liquid medium used as brine is, for example, an aqueous solution of sodium chloride, an aqueous solution of calcium chloride, an aqueous solution of ethylene glycol, an aqueous solution of propylene glycol, or the like. However, the liquid medium is not limited to the types exemplified here, and may be appropriately selected. In one or more embodiments, brine is used as the liquid medium.
- In one or more embodiments, the refrigerant is a flammable refrigerant. Note that, here, flammable refrigerants includes refrigerants that fall into Class 3 (higher flammability), Class 2 (flammable), and Subclass 2L (lower flammability) in the standard of ASHRAE 34 Designation and safety classification of refrigerant of the United States of America, or the standard of ISO 817 Refrigerants—Designation and safety classification. For example,
FIG. 19 shows a specific example of the refrigerant used in one or more embodiments. “ASHRAE Number” inFIG. 19 indicates an ASHRAE number of a refrigerant defined by ISO 817, “Composition” indicates an ASHRAE number of a substance contained in the refrigerant, “Mass %” indicates a mass percent concentration of each substance contained in the refrigerant, and “Alternative” indicates a name of a substance of the refrigerant that is often replaced by the refrigerant. In one or more embodiments, the refrigerant to be used is R32. The refrigerants illustrated inFIG. 19 have a feature of having a higher density than air. - An installation place is not limited, but the
heat exchange unit 100 is installed indoors, for example. In one or more embodiments, theheat exchange unit 100 is installed in the machine room R together with other devices (devices OD1 to OD3 inFIG. 3 ) as shown inFIG. 3 . The devices OD1 to OD3 include, but are not limited to, a boiler, a generator, a switchboard, and the like. However, only theheat exchange unit 100 may be installed in the machine room R. Further, theheat exchange unit 100 may be installed outdoors such as on a rooftop of a building or around a building. - The
heat source unit 300 is a device that uses air as a heat source to cool or heat the refrigerant. Theheat source unit 300 is connected to theheat exchange unit 100 via a liquid-refrigerant connection pipe 52 and a gas-refrigerant connection pipe 54, and form arefrigerant circuit 50 together with theheat exchange unit 100. Therefrigerant circuit 50 mainly has acompressor 330, a flowpath switching mechanism 332, a heat-source-side heat exchanger 340, and asecond expansion mechanism 344 of theheat source unit 300, which will be described later, a utilization-side heat exchanger 10 and afirst expansion mechanism 20 of theheat exchange unit 100, which will be described later, and the like. An installation place is not limited, but theheat source unit 300 is installed, for example, on a rooftop or around of a building, or the like. - In one or more embodiments, the heat load processing system 1 has the four heat source units 300 (see
FIG. 2 ). Then, theheat exchange unit 100 cools or heats the liquid medium with the refrigerant cooled or heated in the fourheat source units 300. However, the number ofheat source units 300 is an example, and the number is not limited to four. The number ofheat source units 300 may be, for example, one to three, or five or more. - The utilization-
side equipment 410 is equipment that uses or stores the liquid medium cooled or heated by theheat exchange unit 100. The utilization-side equipment 410 is connected to theheat exchange unit 100 via a liquidmedium connection pipe 420 to form a liquidmedium circuit 400. In the liquidmedium circuit 400, the liquid medium sent by apump 60 of theheat exchange unit 100, which will be described later, circulates. - The utilization-
side equipment 410 is, for example, an air handling unit or a fan coil unit that performs air conditioning by exchanging heat between air and the liquid medium cooled or heated by theheat exchange unit 100. However, the utilization-side equipment 410 may be, for example, manufacturing equipment that cools or heats a manufacturing device or a manufactured product by using the liquid medium cooled or heated by theheat exchange unit 100. Further, the utilization-side equipment 410 may be, for example, a tank that stores the liquid medium cooled or heated by theheat exchange unit 100. The liquid medium stored in the tank as the utilization-side equipment 410 is, for example, sent to a device using the liquid medium by a pump or the like (not illustrated). -
FIG. 2 illustrates only one piece of the utilization-side equipment 410. However, the heat load processing system 1 includes multiple pieces of utilization-side equipment, and the liquid medium cooled or heated by theheat exchange unit 100 may be sent to the multiple pieces of utilization-side equipment. When the heat load processing system 1 includes a multiple pieces of utilization-side equipment, types of the multiple pieces of utilization-side equipment may all be the same, or the multiple pieces of utilization-side equipment may include a plurality of types of equipment. - The
heat source unit 300, the liquid-refrigerant connection pipe 52 and the gas-refrigerant connection pipe 54, the liquidmedium circuit 400, and theheat exchange unit 100 will be described in detail. - (2-1) Heat-Source-Side Unit
- The
heat source unit 300 will be described with reference toFIG. 2 . Note that, inFIG. 2 , an internal configuration is drawn only for one of fourheat source units 300, and drawing of an internal configuration of the other three is omitted. Theheat source units 300 omitted from the drawing also have a configuration similar to theheat source unit 300 described below. - The
heat source unit 300 mainly includes an in-unit refrigerant pipe 350, thecompressor 330, the flowpath switching mechanism 332, the heat-source-side heat exchanger 340, thesecond expansion mechanism 344, afan 342, a gas-side shutoff valve 304, a liquid-side shutoff valve 302, and a heat-source-side control board 395 (seeFIG. 2 ). - (2-1-1) In-Unit Pipe
- The in-
unit refrigerant pipe 350 is a pipe connecting between configurations of theheat source unit 300, including thecompressor 330, the flowpath switching mechanism 332, the heat-source-side heat exchanger 340, thesecond expansion mechanism 344, the gas-side shutoff valve 304, and the liquid-side shutoff valve 302. The in-unit refrigerant pipe 350 includes asuction pipe 351, adischarge pipe 352, a first gas-side pipe 353, a liquid-side pipe 354, and a second gas-side pipe 355 (seeFIG. 2 ). - The
suction pipe 351 is a pipe that connects a suction port (not illustrated) of thecompressor 330 and the flowpath switching mechanism 332. Thesuction pipe 351 is provided with an accumulator (not illustrated). Thedischarge pipe 352 is a pipe that connects a discharge port (not illustrated) of thecompressor 330 and the flowpath switching mechanism 332. The first gas-side pipe 353 is a pipe that connects the flowpath switching mechanism 332 and a gas side of the heat-source-side heat exchanger 340. The liquid-side pipe 354 is a pipe that connects a liquid side of the heat-source-side heat exchanger 340 and the liquid-side shutoff valve 302. In the liquid-side pipe 354, thesecond expansion mechanism 344 is arranged. The second gas-side pipe 355 is a pipe that connects the flowpath switching mechanism 332 and the gas-side shutoff valve 304. - (2-1-2) Compressor
- The
compressor 330 suctions a low-pressure refrigerant in a refrigeration cycle through thesuction pipe 351, compresses the refrigerant by a compression mechanism (not illustrated), and discharges a high-pressure refrigerant in the refrigeration cycle after compression through thedischarge pipe 352. - The
compressor 330 is, for example, a scroll-type compressor. However, a type of thecompressor 330 is not limited to the scroll type, and the compressor may be, for example, a screw type, a rotary type, or the like. Thecompressor 330 is, for example, a compressor having a variable capacity, but may be, for example, a compressor having a constant capacity. - (2-1-3) Flow Path Switching Mechanism
- The flow
path switching mechanism 332 is a mechanism to switch a flow direction of the refrigerant in therefrigerant circuit 50 in accordance with an operating mode of the heat load processing system 1. The operating modes of the heat load processing system 1 include a mode for cooling the liquid medium (hereinafter referred to as a cooling mode) and a mode for heating the liquid medium (hereinafter referred to as a heating mode). - In one or more embodiments, the flow
path switching mechanism 332 is a four-way switching valve. However, the flowpath switching mechanism 332 is not limited to the four-way switching valve, and may be configured to be able to realize switching of a flow direction of the refrigerant as follows, by combining a plurality of electromagnetic valves and pipes. - In the cooling mode, the flow
path switching mechanism 332 switches the flow direction of the refrigerant in therefrigerant circuit 50 so that the refrigerant discharged by thecompressor 330 is sent to the heat-source-side heat exchanger 340. Specifically, in the cooling mode, the flowpath switching mechanism 332 connects thesuction pipe 351 with the second gas-side pipe 355, and connects thedischarge pipe 352 with the first gas-side pipe 353 (see a solid line in the flowpath switching mechanism 332 inFIG. 2 ). - In the heating mode, the flow
path switching mechanism 332 switches the flow direction of the refrigerant in therefrigerant circuit 50 so that the refrigerant discharged by thecompressor 330 is sent to the utilization-side heat exchanger 10 of theheat exchange unit 100. Specifically, in the heating mode, the flowpath switching mechanism 332 connects thesuction pipe 351 with the first gas-side pipe 353, and connects thedischarge pipe 352 with the second gas-side pipe 355 (see a broken line in the flowpath switching mechanism 332 inFIG. 2 ). - (2-1-4) Heat-Source-Side Heat Exchanger
- The heat-source-
side heat exchanger 340 is a heat exchanger that exchanges heat between air around theheat source unit 300 and a refrigerant flowing inside the heat-source-side heat exchanger 340. The heat-source-side heat exchanger 340 is, for example, a cross-fin type fin-and-tube heat exchanger, although the type is not limited. The heat-source-side heat exchanger 340 functions as a condenser (a radiator) when the operating mode of the heat load processing system 1 is in the cooling mode. Further, the heat-source-side heat exchanger 340 functions as an evaporator when the operating mode of the heat load processing system 1 is in the heating mode. - (2-1-5) Second Expansion Mechanism
- The
second expansion mechanism 344 is a mechanism that expands a refrigerant flowing through the liquid-side pipe 354, to adjust a pressure and a flow rate of the refrigerant. In one or more embodiments, thesecond expansion mechanism 344 is an electronic expansion valve whose opening degree is adjustable. However, thesecond expansion mechanism 344 is not limited to the electronic expansion valve. For example, thesecond expansion mechanism 344 may be a temperature automatic expansion valve having a temperature sensing cylinder, or may be a capillary tube. - (2-1-6) Fan
- The
fan 342 is a mechanism to generate an air flow so that air passes through the heat-source-side heat exchanger 340, in order to promote heat exchange between the refrigerant and air in the heat-source-side heat exchanger 340. Thefan 342 is, for example, a propeller fan, although the type is not limited. - (2-1-7) Liquid-Side Shutoff Valve
- The liquid-
side shutoff valve 302 is a valve that switches between communication and non-communication between the liquid-refrigerant connection pipe 52 and the liquid-side pipe 354. One end of the liquid-side shutoff valve 302 is connected with the liquid-refrigerant connection pipe 52, and another end of the liquid-side shutoff valve 302 is connected with the liquid-side pipe 354 (seeFIG. 2 ). - (2-1-8) Gas-Side Shutoff Valve
- The gas-
side shutoff valve 304 is a valve that switches between communication and non-communication between the gas-refrigerant connection pipe 54 and the second gas-side pipe 355. One end of the gas-side shutoff valve 304 is connected with the gas-refrigerant connection pipe 54, and another end of the gas-side shutoff valve 304 is connected with the second gas-side pipe 355 (seeFIG. 2 ). - (2-1-9) Heat-Source-Side Control Board
- The heat-source-
side control board 395 functions as acontrol unit 95 a together with a heat-exchange-unitside control board 95 of theheat exchange unit 100 described later. Thecontrol unit 95 a will be described later. - The heat-source-
side control board 395 has various electric circuits, a microcomputer including a CPU and a memory that stores a program executed by the CPU, and the like. - (2-2) Refrigerant Connection Pipe
- (2-2-1) Liquid-Refrigerant Connection Pipe
- The liquid-
refrigerant connection pipe 52 connects the liquid-side shutoff valve 302 of theheat source unit 300 to a liquid-side connecting port 100 a of theheat exchange unit 100, and connects the liquid-side pipe 354 of theheat source unit 300 with an in-heat-exchange-unit liquid-side pipe 56 of theheat exchange unit 100. For connecting the liquid-refrigerant connection pipe 52 and the liquid-side connecting port 100 a of theheat exchange unit 100, for example, a flare joint is used. However, a connection method between the liquid-refrigerant connection pipe 52 and the liquid-side connecting port 100 a of theheat exchange unit 100 is not limited to the connection method using the flare joint, but a connection method using a flange joint or a brazing connection may be selected, for example. - (2-2-2) Gas-Refrigerant Connection Pipe
- The gas-
refrigerant connection pipe 54 connects the gas-side shutoff valve 304 of theheat source unit 300 to a gas-side connecting port 100 b of theheat exchange unit 100, and connects the second gas-side pipe 355 of theheat source unit 300 with an in-heat-exchange-unit gas-side pipe 58 of theheat exchange unit 100. The gas-refrigerant connection pipe 54 and the gas-side connecting port 100 b of theheat exchange unit 100 are connected by brazing, for example. However, a connection method between the gas-refrigerant connection pipe 54 and the gas-side connecting port 100 b of theheat exchange unit 100 is not limited to the brazing connection, and a connection method using various pipe joints may be selected. - (2-3) Liquid Medium Circuit
- The liquid
medium circuit 400 is a circuit in which the liquid medium circulates. The liquidmedium circuit 400 is configured by connecting, with a pipe, the utilization-side heat exchanger 10 of theheat exchange unit 100 and the utilization-side equipment 410. - The liquid
medium circuit 400 includes the utilization-side heat exchanger 10 and thepump 60 of theheat exchange unit 100, the utilization-side equipment 410, an in-heat-exchange-unit firstliquid medium pipe 66, an in-heat-exchange-unit secondliquid medium pipe 68, an in-heat-exchange-unit connection pipe 67, afirst connection pipe 422, and asecond connection pipe 424. - The utilization-
side heat exchanger 10 and thepump 60 of theheat exchange unit 100 will be described later. - As described above, the utilization-
side equipment 410 is, for example, an air handling unit or a fan coil unit. Further, for example, as described above, the utilization-side equipment 410 may be manufacturing equipment that cools or heats a manufacturing device or a manufactured product by using a liquid medium cooled or heated by theheat exchange unit 100, or may be a tank that stores the liquid medium cooled or heated by theheat exchange unit 100. - The in-heat-exchange-unit first
liquid medium pipe 66 is a pipe that connects a liquidmedium inlet 62 of theheat exchange unit 100 and the utilization-side heat exchanger 10 (particularly, afirst heat exchanger 10 a described later). In the in-heat-exchange-unit firstliquid medium pipe 66, thepump 60 is arranged. - The in-heat-exchange-unit second
liquid medium pipe 68 is a pipe that connects the utilization-side heat exchanger 10 (particularly, asecond heat exchanger 10 b described later) and a liquidmedium outlet 64 of theheat exchange unit 100. - The in-heat-exchange-
unit connection pipe 67 is a pipe that connects thefirst heat exchanger 10 a and thesecond heat exchanger 10 b, which will be described later. - The
first connection pipe 422 is a pipe that connects the utilization-side equipment 410 and the liquidmedium inlet 62 of theheat exchange unit 100. Although a connection method is not limited, thefirst connection pipe 422 is connected to the liquidmedium inlet 62 of theheat exchange unit 100, for example, by a flange joint. Alternatively, thefirst connection pipe 422 may be screwed or welded to be connected to the liquidmedium inlet 62 of theheat exchange unit 100. - The
second connection pipe 424 is a pipe that connects the liquidmedium outlet 64 of theheat exchange unit 100 and the utilization-side equipment 410. Although a connection method is not limited, thesecond connection pipe 424 is connected to the liquidmedium outlet 64 of theheat exchange unit 100, for example, by a flange joint. Alternatively, thesecond connection pipe 424 may be screwed or welded to be connected to the liquidmedium outlet 64 of theheat exchange unit 100. - When the
pump 60 is operated, the liquid medium flows through the liquidmedium circuit 400 as follows. - The liquid medium having flowed out from the utilization-
side equipment 410 flows through thefirst connection pipe 422 toward the liquidmedium inlet 62 of theheat exchange unit 100. The liquid medium having flowed into theheat exchange unit 100 from the liquidmedium inlet 62 passes through the in-heat-exchange-unit firstliquid medium pipe 66 to flow into the utilization-side heat exchanger 10. When the liquid medium passes through the utilization-side heat exchanger 10, the liquid medium is cooled or heated by exchanging heat with the refrigerant flowing through therefrigerant circuit 50. The liquid medium cooled or heated by the utilization-side heat exchanger 10 flows out from the utilization-side heat exchanger 10, and flows through the in-heat-exchange-unit secondliquid medium pipe 68 toward the liquidmedium outlet 64. The liquid medium having flowed out of theheat exchange unit 100 from the liquidmedium outlet 64 flows through thesecond connection pipe 424 to flow into the utilization-side equipment 410. - (2-4) Heat Exchange Unit
- The
heat exchange unit 100 is a unit that exchanges heat between a liquid medium sent to the utilization-side equipment 410 and a refrigerant, to perform at least one of cooling and heating of the liquid medium. As described above, theheat exchange unit 100 of one or more embodiments is a unit that exchanges heat between the liquid medium sent to the utilization-side equipment 410 and the refrigerant, to perform both cooling and heating of the liquid medium. - Note that, when the
heat exchange unit 100 is a unit intended only for cooling the liquid medium, theheat source unit 300 need not have the flowpath switching mechanism 332. Further, when theheat exchange unit 100 is a unit intended only for heating the liquid medium, in particular, in a case of not performing a reverse cycle defrost operation for supplying the refrigerant discharged from thecompressor 330 to the heat-source-side heat exchanger 340 to remove frost attached to the heat-source-side heat exchanger 340, theheat source unit 300 need not have the flowpath switching mechanism 332 described above. - The
heat exchange unit 100 mainly includes thecasing 90, adrain pan 80, the utilization-side heat exchanger 10, afirst expansion mechanism 20, thepump 60, agas detection sensor 70, and an electric component box 92 (seeFIGS. 4 to 7 ). - The
heat exchange unit 100 has thefirst expansion mechanisms 20 of the same number as the number of the heat source units 300 (the same number as the number of therefrigerant circuits 50 including theheat source unit 300 and the heat exchange unit 100). In one or more embodiments, theheat exchange unit 100 has fourfirst expansion mechanisms 20. - The
heat exchange unit 100 of one or more embodiments has two utilization-side heat exchangers 10 (thefirst heat exchanger 10 a and thesecond heat exchanger 10 b) connected in series in the liquidmedium circuit 400. However, the number of utilization-side heat exchangers 10 is an example, and is not limited to two. For example, theheat exchange unit 100 may have the utilization-side heat exchangers 10 of the same number (here, four) as the number of theheat source units 300 connected in series in the liquidmedium circuit 400. Further, for example, theheat exchange unit 100 may have only one piece of utilization-side heat exchanger 10, the utilization-side heat exchanger 10 may be connected to all the (here, four)heat source units 300, and therefrigerant circuits 50 of the same number as the number of theheat source units 300 may be configured. Further, theheat exchange unit 100 may have a plurality of utilization-side heat exchangers 10 connected in parallel in the liquidmedium circuit 400. - Further, the
heat exchange unit 100 of one or more embodiments has onepump 60. However, without limiting to this, theheat exchange unit 100 may have a plurality ofpumps 60 connected in series or in parallel in the liquidmedium circuit 400. - (2-4-1) Casing
- The
casing 90 accommodates various components and various devices of theheat exchange unit 100, including thedrain pan 80, the utilization-side heat exchanger 10, thefirst expansion mechanism 20, thepump 60, thegas detection sensor 70, and theelectric component box 92. A top surface and side surfaces of theheat exchange unit 100 are surrounded by a top panel and side plates (seeFIG. 1 ). - In a lower part of the casing 90 (see
FIG. 6 ), thedrain pan 80 is arranged. Above thedrain pan 80, the utilization-side heat exchanger 10 and thepump 60 are arranged (seeFIG. 6 ). Thefirst expansion mechanism 20 is arranged near an upper end of the utilization-side heat exchanger 10, in front of the utilization-side heat exchanger 10 (seeFIG. 6 ). Theelectric component box 92 is arranged at an upper front face side of the casing 90 (seeFIG. 7 ). Theelectric component box 92 is arranged above the utilization-side heat exchanger 10 and the pump 60 (seeFIG. 6 ). - On the front face of the
casing 90, an opening 91 a for maintenance is provided (seeFIG. 6 ). Further, on a back face of thecasing 90, anopening 91 b for maintenance is provided (seeFIG. 9 ). Theopenings casing 90 are closed by side plates of thecasing 90 normally, that is, during operation of the heat load processing system 1. By removing the side plates of thecasing 90 provided on theopenings casing 90 can be maintained or replaced. - On the front face of the casing 90 (in a lower right part of the
casing 90 inFIG. 4 ), four liquid-side connecting ports 100 a and four gas-side connecting ports 100 b of theheat exchange unit 100 are provided. To each liquid-side connecting port 100 a, the liquid-refrigerant connection pipe 52 is connected (seeFIG. 2 ). To each gas-side connecting port 100 b, the gas-refrigerant connection pipe 54 is connected (seeFIG. 2 ). Further, on the back face of thecasing 90, the liquidmedium inlet 62 and the liquidmedium outlet 64 of theheat exchange unit 100 are provided (seeFIGS. 5 and 7 ). To the liquidmedium inlet 62, thefirst connection pipe 422 is connected (seeFIG. 2 ). To the liquidmedium outlet 64, thesecond connection pipe 424 is connected (seeFIG. 2 ). - Note that positions of the liquid-
side connecting port 100 a, the gas-side connecting port 100 b, the liquidmedium inlet 62, and the liquidmedium outlet 64 are not limited to the positions drawn in the figure, and may be changed as appropriate. - (2-4-2) Drain Pan
- The
drain pan 80 will be described with reference toFIGS. 5 to 10 . - Note that
FIG. 8 is a schematic plan view of thedrain pan 80.FIG. 9 is a schematic rear view of a part of the casing 90 (near the drain pan 80) and the drain pan ofFIG. 8 .FIG. 10 is a schematic right side view of thedrain pan 80. - The
drain pan 80 is arranged in a lower part of thecasing 90. In particular, in one or more embodiments, thedrain pan 80 is arranged in a lowermost part of thecasing 90. Thedrain pan 80 is arranged below the utilization-side heat exchanger 10. Further, thedrain pan 80 is arranged below thepump 60. Thedrain pan 80 receives condensation water generated on the utilization-side heat exchanger 10, thepump 60, pipes through which the liquid medium and the refrigerant flow, and the like. When theheat exchange unit 100 is installed outdoors, rainwater or the like also flows into thedrain pan 80. Moreover, thedrain pan 80 may have a function as a bottom plate of thecasing 90. - The
drain pan 80 may be arranged lower than: at least a part of therefrigerant pipe 57 described later; at least a part of the in-heat-exchange-unit firstliquid medium pipe 66, the in-heat-exchange-unit connection pipe 67, and the in-heat-exchange-unit secondliquid medium pipe 68; the utilization-side heat exchanger 10; and thepump 60. In one or more embodiments, thedrain pan 80 may be arranged so as to surround most of a lower part of theheat exchange unit 100. For example, in top view, thedrain pan 80 covers 80% or more of an area of the heat exchange unit 100 (a bottom area of the casing 90). - The
drain pan 80 has abottom plate 82 and aside wall 84. Thebottom plate 82 has a substantially rectangular shape in plan view (seeFIGS. 8 to 10 ). Theside wall 84 extends upward from an outer peripheral edge of the bottom plate 82 (seeFIGS. 9 and 10 ). Although not limited, a height from thebottom plate 82 to theupper end part 84 a of theside wall 84 is about 80 mm at a highest part. That is, a height from an outer peripheral edge on a rear side of thebottom plate 82 to theupper end part 84 a of theside wall 84 is about 80 mm. - A space formed above the
bottom plate 82 of thedrain pan 80 and below anupper end part 84 a of theside wall 84 of thedrain pan 80 is referred to here as an internal space Si of thedrain pan 80. The internal space Si of thedrain pan 80 is a space in which thebottom plate 82 and theside wall 84 surround a lower part and a side surface, and an upper part is open. In other words, the internal space Si of thedrain pan 80 is a space surrounded by thebottom plate 82, theside wall 84, and a virtual plane passing through theupper end part 84 a of theside wall 84. Condensation water having fallen into the internal space Si of thedrain pan 80 is once received by the internal space Si, and discharged from a drain port provided in thedrain pan 80. The drain port is an opening to discharge water in the internal space Si of thedrain pan 80. The drain port is provided on at least one of thebottom plate 82 and theside wall 84 of thedrain pan 80. In one or more embodiments, adrain pipe 86 is attached to theside wall 84 arranged on a rear side of thedrain pan 80 so as to communicate with the internal space Si of thedrain pan 80, and an end part of thedrain pipe 86 on the internal space Si side functions as adrain port 86 a (seeFIG. 8 ). Thedrain port 86 a is provided in a center of theside wall 84 arranged on the rear side of thedrain pan 80. In other words, thedrain pipe 86 is attached to a center of theside wall 84 arranged on the rear side of thedrain pan 80. Thedrain pipe 86 is attached to a lower part of theside wall 84 arranged on the rear side of the drain pan 80 (seeFIG. 9 ). - Note that, in one or more embodiments, the
drain pan 80 is provided with only one drain port, but the configuration is not limited to this, and drain ports may be provided at a plurality of places. Further, the drain port need not be formed by a pipe fixed to thebottom plate 82 or theside wall 84 of thedrain pan 80, but the drain port may be provided by simply forming a hole in thebottom plate 82 or theside wall 84 of thedrain pan 80. - The
bottom plate 82 of thedrain pan 80 has aninclined part 82 a that is inclined with respect to a horizontal plane. In particular, in one or more embodiments, theentire bottom plate 82 is inclined with respect to the horizontal plane, and theentire bottom plate 82 functions as theinclined part 82 a. In one or more embodiments, theinclined part 82 a is inclined so as to be lowered from a front side to a rear side, and has anupper end 82 aa on the front side and alower end 82 ab on the rear side (seeFIG. 10 ). That is, in one or more embodiments, thebottom plate 82 is lowered toward theside wall 84 arranged on the rear side of thedrain pan 80 provided with thedrain port 86 a, and water is easily discharged from the internal space Si of thedrain pan 80 through thedrain port 86 a. - Note that the
bottom plate 82 of thedrain pan 80 need not be entirely inclined with respect to the horizontal plane as in the above-described embodiments. That is, thebottom plate 82 may have theinclined part 82 a only partially. For example, in thebottom plate 82 of thedrain pan 80, a region where condensation water is unlikely to fall need not be provided with an inclination. - (2-4-3) Utilization-Side Heat Exchanger
- The utilization-
side heat exchanger 10 includes thefirst heat exchanger 10 a and thesecond heat exchanger 10 b. - Note that, in the following description, features common to the
first heat exchanger 10 a and thesecond heat exchanger 10 b will be described as a description of the utilization-side heat exchanger 10 without distinguishing as thefirst heat exchanger 10 a or thesecond heat exchanger 10 b. - The utilization-
side heat exchanger 10 exchanges heat between the refrigerant and the liquid medium. In one or more embodiments, the utilization-side heat exchanger 10 is a plate-type heat exchanger. However, a type of the utilization-side heat exchanger 10 is not limited to the plate-type heat exchanger, and it is sufficient to appropriately select a heat exchanger of a type that can be used as a heat exchanger between the refrigerant and the liquid medium. - To the
first heat exchanger 10 a and thesecond heat exchanger 10 b, two in-heat-exchange-unit liquid-side pipes 56 and two in-heat-exchange-unit gas-side pipes 58 are individually connected. Further, to thefirst heat exchanger 10 a, the in-heat-exchange-unit firstliquid medium pipe 66 and the in-heat-exchange-unit connection pipe 67 are connected. To thesecond heat exchanger 10 b, the in-heat-exchange-unit connection pipe 67 and the in-heat-exchange-unit secondliquid medium pipe 68 are connected. The in-heat-exchange-unit connection pipe 67 is a pipe that connects a liquid medium flow path (not illustrated) in thefirst heat exchanger 10 a with a liquid medium flow path in thesecond heat exchanger 10 b. - When the
pump 60 is operated, the liquid medium passes through thefirst connection pipe 422 and the in-heat-exchange-unit firstliquid medium pipe 66 to flow into thefirst heat exchanger 10 a, and passes through the liquid medium flow path (not illustrated) in thefirst heat exchanger 10 a to flow out to the in-heat-exchange-unit connection pipe 67. The liquid medium having flowed out from thefirst heat exchanger 10 a to the in-heat-exchange-unit connection pipe 67 passes through the in-heat-exchange-unit connection pipe 67 to flow into thesecond heat exchanger 10 b. The liquid medium having flowed into thesecond heat exchanger 10 b passes through the liquid medium flow path (not illustrated) in thesecond heat exchanger 10 b, and further passes through the in-heat-exchange-unit secondliquid medium pipe 68 and thesecond connection pipe 424, to be sent to the utilization-side equipment 410. - When the operating mode of the heat load processing system 1 is in the cooling mode, to each utilization-
side heat exchanger 10, the refrigerant flows from the in-heat-exchange-unit liquid-side pipe 56 into a refrigerant flow path (not illustrated) in each utilization-side heat exchanger 10. The liquid medium flowing through the liquid medium flow path (not illustrated) in each utilization-side heat exchanger 10 is cooled by exchanging heat with the refrigerant flowing through the refrigerant flow path (not illustrated) in each utilization-side heat exchanger 10. The refrigerant having flowed through the refrigerant flow path (not illustrated) in each utilization-side heat exchanger 10 flows into the in-heat-exchange-unit gas-side pipe 58, and passes through the gas-refrigerant connection pipe 54 to flow into the second gas-side pipe 355 of theheat source unit 300. - Whereas, when the operating mode of the heat load processing system 1 is in the heating mode, to each utilization-
side heat exchanger 10, the refrigerant flows from the in-heat-exchange-unit gas-side pipe 58 into the refrigerant flow path (not illustrated) in each utilization-side heat exchanger 10. The liquid medium flowing through the liquid medium flow path (not illustrated) in each utilization-side heat exchanger 10 is heated by exchanging heat with the refrigerant flowing through the refrigerant flow path (not illustrated) in each utilization-side heat exchanger 10. The refrigerant having flowed through the refrigerant flow path (not illustrated) in each utilization-side heat exchanger 10 flows into the in-heat-exchange-unit liquid-side pipe 56, and passes through the liquid-refrigerant connection pipe 52 to flow into the liquid-side pipe 354 of theheat source unit 300. - (2-4-4) First Expansion Mechanism
- The
first expansion mechanism 20 is a mechanism that expands a refrigerant flowing through the in-heat-exchange-unit liquid-side pipe 56, to adjust a pressure and a flow rate of the refrigerant. - In one or more embodiments, the
first expansion mechanism 20 is an electronic expansion valve whose opening degree is adjustable. The electronic expansion valve as thefirst expansion mechanism 20 is arranged near an upper end of the utilization-side heat exchanger 10, in front of the utilization-side heat exchanger 10. However, thefirst expansion mechanism 20 is not limited to the electronic expansion valve. For example, thefirst expansion mechanism 20 may be a temperature automatic expansion valve having a temperature sensing cylinder, or may be a capillary tube. - (2-4-5) Pump
- The
pump 60 is a pump that sends the liquid medium to the utilization-side equipment 410. Thepump 60 is arranged in the in-heat-exchange-unit firstliquid medium pipe 66. - The
pump 60 is, for example, a constant speed centrifugal pump. However, thepump 60 is not limited to the centrifugal pump, and a type of thepump 60 may be appropriately selected. Further, thepump 60 may be, for example, a pump having a variable flow rate. - Note that, in one or more embodiments, the
pump 60 is arranged upstream of the utilization-side heat exchanger 10 in a flow direction of the liquid medium in the liquidmedium circuit 400, in other words, in the in-heat-exchange-unit firstliquid medium pipe 66. However, without limiting to this, thepump 60 may be arranged downstream of the utilization-side heat exchanger 10 in the flow direction of the liquid medium in the liquidmedium circuit 400, in other words, in the in-heat-exchange-unit secondliquid medium pipe 68. - (2-4-6) Gas Detection Sensor
- The
gas detection sensor 70 is a sensor that detects the presence or absence of refrigerant gas in the internal space Si of thedrain pan 80. In one or more embodiments, thegas detection sensor 70 may have adetection element 72, and may detect the presence or absence of refrigerant gas at a place where thedetection element 72 is arranged. - The
detection element 72 is, for example, a semiconductor-type sensor element. Electrical conductivity of the semiconductor-type detection element changes depending on a state where no refrigerant gas is present in the surroundings or a state where refrigerant gas is present. Thegas detection sensor 70 includes a detection circuit (not illustrated) that is electrically connected to thedetection element 72, and detects the presence or absence of the refrigerant gas by detecting a change in electrical conductivity of thedetection element 72 with the detection circuit. - However, the
detection element 72 is not limited to the semiconductor-type element, and may be any element capable of detecting the refrigerant gas. For example, thegas detection sensor 70 may include an infrared light source (not illustrated) and an infrared detection element as thedetection element 72, and may detect the presence or absence of the refrigerant gas by detecting a change in a detection amount of infrared rays of thedetection element 72, which changes depending on the presence or absence of refrigerant gas, with a detection circuit that is electrically connected to thedetection element 72. - As described above, since the refrigerant gas has a higher density than air, the refrigerant gas easily moves to a lower position when the refrigerant leaks in the
heat exchange unit 100. Therefore, leaked refrigerant gas tends to accumulate in the internal space Si of thedrain pan 80. In particular, in one or more embodiments, since thedrain pan 80 covers most of the lower part of theheat exchange unit 100, for example, 80% or more of the bottom area of thecasing 90 in top view, leaked refrigerant gas tends to accumulate in the internal space Si of thedrain pan 80. Therefore, thedetection element 72 of thegas detection sensor 70 may be arranged in the internal space Si of thedrain pan 80 located at the lower part in thecasing 90. In one or more embodiments, thedetection element 72 may be arranged on thelower end 82 ab side of theinclined part 82 a of thebottom plate 82 of the drain pan 80 (in one or more embodiments, a rear end side of the bottom plate 82). Further, thedetection element 72 may be arranged near thedrain port 86 a, which is a discharge port of water from the internal space Si of thedrain pan 80. - In one or more embodiments, the
detection element 72 of thegas detection sensor 70 is arranged on thelower end 82 ab side of theinclined part 82 a in the internal space Si of the drain pan 80 (seeFIG. 10 ). Further, thedetection element 72 of thegas detection sensor 70 is arranged at a position adjacent to thedrain port 86 a provided on theside wall 84 on the rear side of the drain pan 80 (seeFIGS. 8 to 10 ). By arranging thedetection element 72 at such a position where refrigerant gas is likely to accumulate, highly reliable refrigerant leakage detection is possible. - Note that the position where the
detection element 72 of thegas detection sensor 70 is arranged is an example, and is not limited to the position drawn inFIGS. 8 to 10 . - For example, the position where the
detection element 72 of thegas detection sensor 70 is arranged may be, for example, away from thedrain port 86 a, in the vicinity of theside wall 84 on the rear side of the drain pan 80 (on thelower end 82 ab side of theinclined part 82 a). - In addition, for example, when a place is specified where there is a relatively high possibility of leakage of the refrigerant gas, the
detection element 72 of thegas detection sensor 70 may be arranged near the place where the possibility of leakage of the refrigerant gas is relatively high, in the internal space Si of thedrain pan 80. In this case, thedetection element 72 of thegas detection sensor 70 may be arranged at a place other than thelower end 82 ab side of theinclined part 82 a (for example, theupper end 82 aa side of theinclined part 82 a). - Further, for example, the
detection element 72 of thegas detection sensor 70 need not be arranged in the internal space Si of thedrain pan 80. For example, thegas detection sensor 70 may use thedetection element 72 arranged very close to theupper end part 84 a, at a position higher than theupper end part 84 a of theside wall 84 of thedrain pan 80, to detect the presence or absence of the refrigerant gas in the internal space Si of thedrain pan 80. In addition, thegas detection sensor 70 may use thedetection element 72 arranged at another place outside the internal space Si of thedrain pan 80 and where the gas in the internal space Si of thedrain pan 80 can be detected, to detect the presence or absence of the refrigerant gas in the internal space Si of thedrain pan 80. For example, the place outside the internal space Si of thedrain pan 80 and where the gas in the internal space Si of thedrain pan 80 can be detected includes an opening on an opposite side of thedrain port 86 a of thedrain pipe 86. - Further, the
detection element 72 of thegas detection sensor 70 may be arranged below an electric component that can be an ignition source (seeFIGS. 6 and 7 ). By arranging thedetection element 72 below the electric component that can be an ignition source, refrigerant leakage is easily detected before the refrigerant gas reaches a height position of the electric component that can be an ignition source from the bottom side of thecasing 90, even if the refrigerant leaks in theheat exchange unit 100. - Note that the electric component that can be an ignition source include an electric component that may generate an electric spark. In one or more embodiments, the electric components that can be an ignition source include: the
electric components 93 such as an electromagnetic switch, a contactor, and a relay accommodated in theelectric component box 92, which will be described later; an electronic expansion valve as an example of thefirst expansion mechanism 20; and theterminal box 61 of thepump 60. Theterminal box 61 of thepump 60 is connected with anelectric wire 61 a for supply of electric power to amotor 60 a of thepump 60. - Further, although it is not mounted on the
heat exchange unit 100 of the above-described embodiments, a heater may be arranged in theheat exchange unit 100 when theheat exchange unit 100 is installed in a cold region. Depending on specifications, the heater can be hot enough to be an ignition source. In one or more embodiments, the electric component that can become hot enough to be an ignition source may also be arranged above thedetection element 72 of thegas detection sensor 70. - Further, the
detection element 72 of thegas detection sensor 70 may be arranged below the liquid-side connecting port 100 a and the gas-side connecting port 100 b of theheat exchange unit 100, which is where refrigerant is relatively likely to leak (seeFIGS. 6 and 7 ). Whereas, the electric component that can be an ignition source may be arranged above the liquid-side connecting port 100 a and the gas-side connecting port 100 b of theheat exchange unit 100. Such an arrangement allows refrigerant leakage to be easily detected before the refrigerant gas reaches a height position of the electric component that can be an ignition source from the bottom side of thecasing 90, even if the refrigerant leaks at the liquid-side connecting port 100 a or the gas-side connecting port 100 b of theheat exchange unit 100. - Moreover, the electric component that can be an ignition source (in one or more embodiments: the
electric components 93 such as an electromagnetic switch, a contactor, and a relay accommodated in theelectric component box 92; an electronic expansion valve as an example of thefirst expansion mechanism 20; and theterminal box 61 of the pump 60) may be arranged at a position that is 300 mm or more higher than a bottom of the casing 90 (seeFIGS. 6 and 7 ). By arranging the electric component that can be an ignition source at such a height position, the possibility of ignition with the electric component in thecasing 90 as the ignition source is reduced even if the refrigerant leaks. - Further, if the refrigerant leaks, there is a high possibility that the refrigerant leaks from the utilization-
side heat exchanger 10, or arefrigerant pipe 57 including the in-heat-exchange-unit liquid-side pipe 56 and the in-heat-exchange-unit gas-side pipe 58. Therefore, thedetection element 72 of thegas detection sensor 70 may be arranged at the following position. - In plan view, an inside of the
casing 90 is sectioned into at least a pump arrangement area A1 where thepump 60 is arranged, and a refrigerant side area A2 where therefrigerant pipe 57 through which the refrigerant flows or the utilization-side heat exchanger 10 is arranged (seeFIGS. 5 and 8 ). That is, in plan view, the pump arrangement area A1 and the refrigerant side area A2 exist inside thecasing 90. As shown inFIG. 8 , thedetection element 72 of thegas detection sensor 70 may be arranged closer to the refrigerant side area A2 than the pump arrangement area A1. - Further, from the viewpoint of maintenance, the
detection element 72 of thegas detection sensor 70 may be arranged in a space near theopening 91 b for maintenance, in thecasing 90. The space near theopening 91 b is a space accessible to a worker from theopening 91 b. For example, the space near theopening 91 b is a space within hand reach from theopening 91 b (for example, a space within 50 cm from theopening 91 b). An arrangement of thedetection element 72 of thegas detection sensor 70 at such a position allows thedetection element 72 to be easily replaced and inspected by removing the side plate of thecasing 90 that closes theopening 91 b. - Further, since the
detection element 72 of thegas detection sensor 70 detects the refrigerant gas, it may be that thedetection element 72 is arranged at a position that is less likely to be immersed even if condensation water accumulates in the internal space Si of thedrain pan 80. - For example, in one or more embodiments, the
heat exchange unit 100 may have afloat 88 that is arranged in the internal space Si of thedrain pan 80, and thedetection element 72 may be attached to anupper surface 88 a or aside surface 88 b of thefloat 88. Thefloat 88 is a member configured to float on a water surface when condensation water accumulates in the internal space Si of thedrain pan 80. - A structure of the
float 88 will be more specifically described. For example, specifically, thefloat 88 has amain body 881, and aswing shaft 882 that is swingably supported by a support part (not illustrated) provided on theside wall 84 of thedrain pan 80 or a frame (not illustrated) of the casing 90 (seeFIGS. 11A and 11B ). Themain body 881 is configured to float on water. Thedetection element 72 of thegas detection sensor 70 may be attached to theupper surface 88 a of the float 88 (an upper surface of the main body 881) as shown inFIG. 11A , or may be attached to theside surface 88 b (a side surface of the main body 881) of thefloat 88 as shown inFIG. 11B . When there is no water in thedrain pan 80, themain body 881 of thefloat 88 is located at a first position. Although not limited, themain body 881 of thefloat 88 located at the first position is in contact with thebottom plate 82 of thedrain pan 80, as shown by solid lines inFIGS. 11A and 11B . Whereas, when water accumulates in thedrain pan 80, themain body 881 of thefloat 88 swings around theswing shaft 882 and floats due to buoyancy as shown by two-dot chain lines inFIGS. 11A and 11B . Such a configuration facilitates suppression of immersion of thedetection element 72 of thegas detection sensor 70, even when condensation water accumulates in the internal space Si of thedrain pan 80. Therefore, even if, for example, thedrain pipe 86 is clogged for some reason and water is not discharged from thedrain port 86 a, the gas refrigerant can be detected by thegas detection sensor 70 when the refrigerant leaks. - Alternatively, the
heat exchange unit 100 need not have thefloat 88. Then, thedetection element 72 of thegas detection sensor 70 may be directly attached to theside wall 84 of thedrain pan 80 or the frame (not illustrated) of thecasing 90. In this case, thedetection element 72 of thegas detection sensor 70 may be arranged at a position that is less likely to be immersed, for example, a position higher than thedrain port 86 a in the internal space Si of thedrain pan 80, as shown by reference numeral 72 a inFIG. 9 . - (2-4-7) Electric Component Box
- The
electric component box 92 is a case that accommodates various electric components. Theelectric component box 92 accommodates the heat-exchange-unitside control board 95, a power source terminal block (not illustrated), and theelectric components 93 such as an electromagnetic switch, a contactor, and a relay (seeFIG. 2 ). Theelectric component 93 need not include all of the electromagnetic switch, the contactor, and the relay, but may include any of the electromagnetic switch, the contactor, and the relay. Note that the electric components accommodated in theelectric component box 92 are not limited to those exemplified, and various electric components are accommodated as needed. - The heat-exchange-unit
side control board 95 functions as thecontrol unit 95 a together with the heat-source-side control board 395 of theheat source unit 300. The heat-exchange-unitside control board 95 has various electric circuits, a microcomputer including a CPU and a memory that stores a program executed by the CPU, and the like. - The
control unit 95 a controls an operation of each unit of the heat load processing system 1. - The
control unit 95 a is electrically connected to various devices of theheat source unit 300 and theheat exchange unit 100. The various devices of theheat source unit 300 and theheat exchange unit 100 connected to thecontrol unit 95 a include: thecompressor 330, the flowpath switching mechanism 332, thesecond expansion mechanism 344, and thefan 342 of theheat source unit 300; and thefirst expansion mechanism 20 and thepump 60 of theheat exchange unit 100. Further, thecontrol unit 95 a is communicably connected to various sensors provided to theheat source unit 300 and theheat exchange unit 100, and receives measured values from the various sensors (not illustrated). The various sensors provided to theheat exchange unit 100 include, but not limited to, for example, a temperature sensor that is provided in the in-heat-exchange-unit liquid-side pipe 56 or the in-heat-exchange-unit gas-side pipe 58 and measures a temperature of the refrigerant, a pressure sensor provided in the in-heat-exchange-unit liquid-side pipe 56, a temperature sensor provided in the in-heat-exchange-unit firstliquid medium pipe 66, the in-heat-exchange-unit connection pipe 67, and the in-heat-exchange-unit secondliquid medium pipe 68 and measures a temperature of the liquid medium, and the like. Further, the various sensors provided to theheat source unit 300 include, but not limited to, for example, a temperature sensor that is provided in thesuction pipe 351 and measures a suction temperature, a temperature sensor that is provided in thedischarge pipe 352 and measures a discharge temperature, and a pressure sensor that is provided in thedischarge pipe 352 and measures a discharge pressure. Further, thecontrol unit 95 a is communicably connected to thegas detection sensor 70 of theheat source unit 300. - The
control unit 95 a controls an operation of various devices of theheat source unit 300 and theheat exchange unit 100 in response to an operation or stop command given from an operation device (not illustrated). Further, thecontrol unit 95 a controls a state of the flowpath switching mechanism 332 of theheat source unit 300 in accordance with an operating mode (the cooling mode or the heating mode) of the heat load processing system 1. In addition, thecontrol unit 95 a controls an operation of various devices of theheat source unit 300 and theheat exchange unit 100 such that a liquid medium is cooled or heated to reach a predetermined target temperature and flows out from the liquidmedium outlet 64 of theheat exchange unit 100. Note that an operating principle of a vapor compression refrigerator is generally well known, and thus a description thereof is omitted here. In addition, when thegas detection sensor 70 detects leakage of refrigerant gas, thecontrol unit 95 a controls various devices such that various devices of theheat source unit 300 and theheat exchange unit 100 perform a predetermined operation at a time of leakage. - (3-1)
- The
heat exchange unit 100 of the above-described embodiments exchanges heat between a liquid medium sent to utilization-side equipment 410 and the refrigerant, to perform at least one of cooling and heating of the liquid medium. Theheat exchange unit 100 includes the utilization-side heat exchanger 10 as an example of a heat exchanger, thecasing 90, thedrain pan 80, and thegas detection sensor 70. Thegas detection sensor 70 is an example of a first gas detection sensor. The utilization-side heat exchanger 10 exchanges heat between the flammable refrigerant and the liquid medium. Thecasing 90 accommodates the utilization-side heat exchanger 10. Thedrain pan 80 is arranged below the utilization-side heat exchanger 10, in a lower part of thecasing 90. Thedrain pan 80 has thebottom plate 82 and theside wall 84 extending upward from thebottom plate 82. Thegas detection sensor 70 detects the presence or absence of refrigerant gas in the internal space Si of thedrain pan 80, the internal space Si being located above thebottom plate 82 of thedrain pan 80 and below the upper end part of theside wall 84 of thedrain pan 80. - The refrigerant gas is usually heavier than air. Therefore, when the refrigerant leaks, the leaked refrigerant gas moves downward. Therefore, in this
heat exchange unit 100, leaked refrigerant gas tends to accumulate in thedrain pan 80 that is arranged in the lower part of thecasing 90 and receives dew condensation water generated on the pipe, the heat exchanger, and the like. - Here, highly reliable leakage detection of refrigerant gas is possible by detecting the presence or absence of refrigerant gas in the internal space Si of the
drain pan 80 where leaked refrigerant gas tends to accumulate. - In one or more embodiments, the
gas detection sensor 70 may have, as an example of a first detection element, thedetection element 72 that is arranged in the internal space Si of thedrain pan 80, and may detect the presence or absence of the refrigerant gas at a place where thedetection element 72 is arranged. - Here, by arranging the
detection element 72 of thegas detection sensor 70 in the internal space Si of thedrain pan 80 where leaked refrigerant gas tends to accumulate, highly reliable refrigerant leakage detection is possible. - (3-2)
- In the
heat exchange unit 100 of the above-described embodiments, thebottom plate 82 of thedrain pan 80 has theinclined part 82 a that is inclined with respect to a horizontal plane. Thedetection element 72 is arranged on a lower end side of theinclined part 82 a. - Here, since the detection element of the
gas detection sensor 70 is arranged on the lower end side of theinclined part 82 a where the refrigerant gas tends to accumulate, highly reliable refrigerant leakage detection is possible. - (3-3)
- In the
heat exchange unit 100 of the above-described embodiments, at least one of thebottom plate 82 or theside wall 84 of thedrain pan 80 is provided with thedrain port 86 a for discharge of water in the internal space Si of thedrain pan 80. Thedetection element 72 is provided near (e.g., adjacent to) thedrain port 86 a. - Here, since the
detection element 72 of thegas detection sensor 70 is arranged in a position where water is easily discharged, in other words, arranged near thedrain port 86 a of thedrain pan 80 where water (fluid) easily flows, highly reliable refrigerant leakage detection is possible. - (3-4)
- The
heat exchange unit 100 of the above-described embodiments includes thefloat 88 arranged in the internal space Si of thedrain pan 80. Thedetection element 72 is attached to theupper surface 88 a or theside surface 88 b of thefloat 88. - Here, since the
detection element 72 of thegas detection sensor 70 is attached to theupper surface 88 a or theside surface 88 b of thefloat 88, it is possible to detect refrigerant leakage even when water accumulates in thedrain pan 80. - (3-5)
- In the
heat exchange unit 100 of the above-described embodiments, thecasing 90 is formed with theopening 91 b for maintenance. Thedetection element 72 is arranged in a space near (e.g., adjacent to) theopening 91 b. - Here, since the
detection element 72 of thegas detection sensor 70 is arranged in the space near theopening 91 b for maintenance, thedetection element 72 of thegas detection sensor 70 can be easily inspected or replaced. - (3-6)
- The
heat exchange unit 100 of the above-described embodiments includes thepump 60. Thepump 60 is arranged inside thecasing 90. Thepump 60 sends a liquid medium to the utilization-side equipment 410. An inside of thecasing 90 is sectioned into at least the pump arrangement area A1 and the refrigerant side area A2 in plan view. In the pump arrangement area A1, thepump 60 is arranged. In the refrigerant side area A2, therefrigerant pipe 57 through which the refrigerant flows or the utilization-side heat exchanger 10 is arranged. Thedetection element 72 is arranged closer to the refrigerant side area A2 than the pump arrangement area A1 in plan view. - Here, since the
detection element 72 of thegas detection sensor 70 is arranged, inside thecasing 90, relatively close to therefrigerant pipe 57 through which the refrigerant flows and the utilization-side heat exchanger 10, highly reliable refrigerant leakage detection is possible. - The
heat exchange unit 100 of the above-described embodiments includes thepump 60, but the configuration is not limited to this. Thepump 60 may be installed outside thecasing 90 separately from theheat exchange unit 100. - The
heat exchange unit 100 may further have an auxiliarygas detection sensor 270 having adetection element 272 arranged outside the casing 90 (seeFIG. 12 ), in addition to thegas detection sensor 70 having thedetection element 72 arranged in the internal space Si of thedrain pan 80. - The auxiliary
gas detection sensor 270 is a sensor that detects the presence or absence of refrigerant gas at a place where thedetection element 272 is arranged. The auxiliarygas detection sensor 270 is similar to thegas detection sensor 70 except for the installation place of thedetection element 272. - Since the
heat exchange unit 100 has the auxiliarygas detection sensor 270, the auxiliarygas detection sensor 270 can detect refrigerant gas even if the refrigerant gas flows out of thecasing 90, which enhances safety. - Since the refrigerant gas has a higher density than that of air as described above, the
detection element 272 of the auxiliarygas detection sensor 270 may be arranged near a floor surface FL of a unit installation space (for example, the machine room R) where theheat exchange unit 100 is installed. For example, thedetection element 272 may be arranged at a position lower than a height position of 300 mm above the floor surface FL of the machine room R. For example, in some cases, theheat exchange unit 100 may be installed on a foundation (a stand) 2 provided on the floor surface FL in the machine room R (seeFIG. 12 ). In such a case, thedetection element 272 of the auxiliarygas detection sensor 270 may be arranged near the floor surface FL of the machine room R. Thedetection element 272 of the auxiliarygas detection sensor 270 may be arranged at a height position up to 300 mm above the floor surface FL of the machine room R. In this case, thedetection element 272 of the auxiliarygas detection sensor 270 may be arranged at a position lower than the bottom of thecasing 90 of theheat exchange unit 100. - In the above-described embodiments, a liquid medium cooled or heated by the
heat exchange unit 100 circulates in the liquidmedium circuit 400, but the configuration is not limited to this. For example, when the cooled or heated liquid medium itself is used directly, the liquid medium sent to the utilization-side equipment 410 (for example, a tank) may be used as it is without circulating in the liquidmedium circuit 400. - A
heat exchange unit 200 according to one or more embodiments and a heatload processing system 201 including theheat exchange unit 100 will be described with reference to the drawings. -
FIG. 13 is a perspective view of theheat exchange unit 200.FIG. 14 is a schematic configuration diagram of the heatload processing system 201 including theheat exchange unit 200. Note that theheat exchange unit 200 has three systems of an identicalrefrigerant circuit 150, but only one system of therefrigerant circuit 150 is drawn inFIG. 14 .FIG. 15 is a schematic plan view of a lower part inside acasing 190 of theheat exchange unit 200.FIG. 16 is a schematic front view of theheat exchange unit 200 with a side plate of thecasing 190 removed.FIG. 17 is a schematic right side view of theheat exchange unit 200 with a side plate of thecasing 190 removed.FIG. 18 is a schematic rear view of a part of thecasing 190 of the heat exchange unit 200 (near a drain pan 80) and thedrain pan 80. - Note that, in the following description, expressions indicating directions such as “upper”, “lower”, “left”, “right”, “front (front face)”, and “rear (back face)” may be used. Unless otherwise specified, these directions are indicated by arrows in figures.
- First, a difference between the heat
load processing system 201 and the heat load processing system 1 of the above-described embodiments will be outlined. - In the heat load processing system 1, the refrigerant is cooled or heated by exchanging heat between air around the
heat source unit 300 and the refrigerant, in the heat-source-side heat exchanger 340. Whereas, in the heatload processing system 201, a refrigerant is cooled or heated by heat exchange between the refrigerant and a heat-source-side liquid medium flowing through a heat-source-side liquidmedium circuit 500. In one or more embodiments, the heatload processing system 201 is a system in which the refrigerant is cooled by cooling water flowing through the heat-source-side liquidmedium circuit 500, and a liquid medium sent to utilization-side equipment 410 is cooled by the refrigerant in theheat exchange unit 200. However, without limiting to this, the heatload processing system 201 may be, for example, a system in which the refrigerant is heated by a heat-source-side liquid medium (for example, waste warm water) flowing through the heat-source-side liquidmedium circuit 500, and a liquid medium sent to the utilization-side equipment 410 is heated by the refrigerant in theheat exchange unit 200. In addition, for example, the heatload processing system 201 may be a system capable of execution by switching between: a cooling mode in which the refrigerant is cooled by a relatively low temperature heat-source-side liquid medium flowing through the heat-source-side liquidmedium circuit 500, and a liquid medium sent to the utilization-side equipment 410 is cooled by the refrigerant in theheat exchange unit 200; and a heating mode in which the refrigerant is heated by a relatively high temperature heat-source-side liquid medium flowing through the heat-source-side liquidmedium circuit 500, and a liquid medium sent to the utilization-side equipment 410 is heated by the refrigerant in theheat exchange unit 200. Note that, in the following, the liquid medium flowing through the heat-source-side liquidmedium circuit 500 is referred to as a heat-source-side liquid medium, while the liquid medium sent to the utilization-side equipment 410 is simply referred to as a liquid medium. - Further, in the heat load processing system 1, the
refrigerant circuit 50 is formed by theheat source unit 300 and theheat exchange unit 100. Whereas, in the heatload processing system 201, theheat exchange unit 200 has the entirerefrigerant circuit 150. In one or more embodiments, oneheat exchange unit 200 has three systems of therefrigerant circuit 150. However, theheat exchange unit 200 may have one or two systems ofrefrigerant circuit 150, or four or more systems ofrefrigerant circuit 150. - Hereinafter, an overall configuration of the heat
load processing system 201 will be described. - The heat
load processing system 201 mainly includes theheat exchange unit 200, the heat-source-side liquidmedium circuit 500, and the utilization-side equipment 410. - The
heat exchange unit 200 is a device that exchanges heat between a liquid medium sent to the utilization-side equipment 410 and a refrigerant, to perform at least one of cooling and heating of the liquid medium. The liquid medium cooled or heated by the liquid refrigerant in theheat exchange unit 200 is sent to the utilization-side equipment 410. - The exemplified
heat exchange unit 200 drawn inFIG. 14 is a unit that only cools the liquid medium by exchanging heat between the liquid medium and the refrigerant. However, for example, the configuration is not limited to this, and theheat exchange unit 200 may be a unit that only heats the liquid medium by exchanging heat between the liquid medium and the refrigerant. In addition, similarly to theheat exchange unit 100 of the above-described embodiments, theheat exchange unit 200 may be, for example, a device capable of both cooling and heating of the liquid medium by exchanging heat between the liquid medium and the refrigerant. - Note that the liquid medium and the refrigerant used in one or more embodiments are similar to the liquid medium and the refrigerant described in the above-described embodiments. The description is omitted here. The heat-source-side liquid medium used in one or more embodiments is, for example, water or brine.
- The heat-source-side liquid
medium circuit 500 is a liquid medium circuit in which the heat-source-side liquid medium that cools the refrigerant in theheat exchange unit 200 circulates. The heat-source-side liquidmedium circuit 500 mainly includesheat source equipment 510 and a heat-source-side pump 520. - In one or more embodiments, the
heat source equipment 510 is equipment to cool the heat-source-side liquid medium. For example, theheat source equipment 510 is a cooling tower. For example, the cooling tower may be an open type that directly cools the heat-source-side heat medium, or may be a closed type that indirectly cools the heat-source-side heat medium. A type of the heat-source-side liquid medium may be appropriately determined in accordance with a type of the cooling tower and the like. An installation place is not limited, but theheat source equipment 510 is installed, for example, on a rooftop or a space around a building, or the like. - The heat-source-
side pump 520 is a pump that sends the heat-source-side liquid medium cooled by theheat source equipment 510, to theheat exchange unit 200. The heat-source-side pump 520 is, for example, a constant speed centrifugal pump. However, the heat-source-side pump 520 is not limited to the centrifugal pump, and a type of the heat-source-side pump 520 may be appropriately selected. Further, the heat-source-side pump 520 may be, for example, a pump having a variable flow rate. Although an installation place is not limited, the heat-source-side pump 520 is installed in a same machine room R as theheat exchange unit 200, for example. - The utilization-
side equipment 410 is similar to the utilization-side equipment 410 in the heat load processing system 1 of the above-described embodiments. However, in one or more embodiments, the utilization-side equipment 410 is equipment that uses a liquid medium cooled by the refrigerant. For example, although not limited, the utilization-side equipment 410 is an air handling unit or a fan coil unit used only for cooling. Note that the utilization-side equipment 410 is not limited to the equipment that uses the liquid medium cooled by the refrigerant. When the heatload processing system 201 is configured so that the liquid medium is heated by the refrigerant in theheat exchange unit 200, the utilization-side equipment 410 may be, for example, equipment that uses the liquid medium heated by the refrigerant. -
FIG. 14 shows only one piece of utilization-side equipment 410. However, similarly to the above-described embodiments, the heatload processing system 201 may include a plurality of pieces of the utilization-side equipment. In addition, when the heatload processing system 201 includes the plurality of pieces of the utilization-side equipment, types of the pieces of the utilization-side equipment may all be the same, or the pieces of the utilization-side equipment may include a plurality of types of equipment. - The
heat exchange unit 200 will be described in detail. - A liquid
medium circuit 400A in one or more embodiments is similar to the liquidmedium circuit 400 of the above-described embodiments except for the fact that a pump 160 (a device similar to thepump 60 of the above-described embodiments) is arranged outside of the heat exchange unit 200 (a first connection pipe 422), and for a configuration of a liquid medium pipe in theheat exchange unit 200. Here, in the description of theheat exchange unit 200, the liquid medium pipe in theheat exchange unit 200 will be described, and detailed description of other liquidmedium circuit 400A will be omitted. - (2-1) Heat Exchange Unit
- The
heat exchange unit 200 will be described with reference toFIGS. 13 to 18 . - The
heat exchange unit 200 has three systems of therefrigerant circuit 150. InFIG. 14 , only one system of the three systems of therefrigerant circuit 150 is drawn. Since otherrefrigerant circuits 150 are similar to therefrigerant circuit 150 described here, a description thereof will be omitted here. - Since an installation place of the
heat exchange unit 200 is similar to the installation place of theheat exchange unit 100 of the above-described embodiments, a description thereof will be omitted. - The
heat exchange unit 200 mainly includes acompressor 130, a heat-source-side heat exchanger 140, anexpansion mechanism 120, a utilization-side heat exchanger 110, thecasing 190, thedrain pan 80, agas detection sensor 70, and anelectric component box 192. Thecompressor 130, the heat-source-side heat exchanger 140, theexpansion mechanism 120, and the utilization-side heat exchanger 110 are connected by arefrigerant pipe 151, to form therefrigerant circuit 150. Therefrigerant pipe 151 includes a firstrefrigerant pipe 151 a that connects a discharge side of thecompressor 130 and a gas side of the heat-source-side heat exchanger 140. Further, therefrigerant pipe 151 includes a secondrefrigerant pipe 151 b that connects a liquid side of the heat-source-side heat exchanger 140 and a liquid side of the utilization-side heat exchanger 110. In the secondrefrigerant pipe 151 b, theexpansion mechanism 120 is arranged. Further, therefrigerant pipe 151 includes a thirdrefrigerant pipe 151 c that connects a gas side of the utilization-side heat exchanger 110 and a suction side of thecompressor 130. In the thirdrefrigerant pipe 151 c, an accumulator (not illustrated) may be arranged. - In one or more embodiments, the
heat exchange unit 200 is a device that cools the liquid medium with the refrigerant as described above. When theheat exchange unit 200 is a device capable of execution by switching between cooling and heating of the liquid medium with the refrigerant, therefrigerant circuit 150 is provided with a flow path switching mechanism, similarly to therefrigerant circuit 50 of the above-described embodiments. - (2-1-1) Compressor
- The
compressor 130 suctions a low pressure refrigerant in a refrigeration cycle returning from the utilization-side heat exchanger 110, compresses the refrigerant with a compression mechanism (not illustrated), and sends a high-pressure refrigerant in the refrigeration cycle after compression, to the heat-source-side heat exchanger 140. - The
compressor 130 is, for example, a scroll-type compressor. However, a type of thecompressor 130 is not limited to the scroll type, and the compressor may be, for example, a screw type, a rotary type, or the like. Thecompressor 130 is, for example, a compressor having a variable capacity, but may be, for example, a compressor having a constant capacity. - (2-1-2) Heat-Source-Side Heat Exchanger
- The heat-source-
side heat exchanger 140 is a heat exchanger that exchanges heat between a heat-source-side liquid medium flowing in the heat-source-side heat exchanger 140 and a refrigerant flowing in the heat-source-side heat exchanger 140. Although a type is not limited, the heat-source-side heat exchanger 340 is, for example, a double-tube heat exchanger. However, a type of the heat-source-side heat exchanger 340 is not limited to the double-tube heat exchanger, and it is sufficient to appropriately select a heat exchanger of a type that can be used as a heat exchanger between the refrigerant and the heat-source-side liquid medium. - (2-1-3) Expansion Mechanism
- The
expansion mechanism 120 is a mechanism that expands a refrigerant flowing through the secondrefrigerant pipe 151 b, to adjust a pressure and a flow rate of the refrigerant. In one or more embodiments, theexpansion mechanism 120 is an electronic expansion valve whose opening degree is adjustable. However, theexpansion mechanism 120 is not limited to the electronic expansion valve. For example, theexpansion mechanism 120 may be a temperature automatic expansion valve having a temperature sensing cylinder, or may be a capillary tube. - (2-1-4) Utilization-Side Heat Exchanger
- The utilization-
side heat exchanger 110 exchanges heat between the refrigerant and the liquid medium. In one or more embodiments, the utilization-side heat exchanger 110 is a plate-type heat exchanger. However, a type of the utilization-side heat exchanger 110 is not limited to the plate-type heat exchanger, and it is sufficient to appropriately select a heat exchanger of a type that can be used as a heat exchanger between the refrigerant and the liquid medium. - The utilization-
side heat exchanger 110 is connected with the secondrefrigerant pipe 151 b, the thirdrefrigerant pipe 151 c, a first in-heat-exchange-unit liquidmedium pipe 166, and a second in-heat-exchange-unit liquidmedium pipe 168. The first in-heat-exchange-unit liquidmedium pipe 166 is a pipe that connects a liquidmedium inlet 162 of theheat exchange unit 200 and the utilization-side heat exchanger 110. The second in-heat-exchange-unit liquidmedium pipe 168 is a pipe that connects the utilization-side heat exchanger 110 and a liquidmedium outlet 164 of theheat exchange unit 200. The liquidmedium inlet 162 of theheat exchange unit 200 is connected with thefirst connection pipe 422 that connects the utilization-side equipment 410 and the liquidmedium inlet 162 of theheat exchange unit 200. The liquidmedium outlet 164 of theheat exchange unit 200 is connected with asecond connection pipe 424 that connects the utilization-side equipment 410 and the liquidmedium outlet 164 of theheat exchange unit 200. - When the
compressor 130 is operated, the refrigerant flows from the secondrefrigerant pipe 151 b into the utilization-side heat exchanger 110, and flows through a refrigerant flow path (not illustrated) in the utilization-side heat exchanger 110 to flow out to the thirdrefrigerant pipe 151 c. Further, when thepump 160 is operated, the liquid medium having flowed out from the utilization-side equipment 410 flows through thefirst connection pipe 422 toward the liquidmedium inlet 162 of theheat exchange unit 200. The liquid medium having flowed into theheat exchange unit 200 from the liquidmedium inlet 162 passes through the first in-heat-exchange-unit liquidmedium pipe 166 to flow into the utilization-side heat exchanger 110. When the liquid medium passes through a liquid medium flow path (not illustrated) of the utilization-side heat exchanger 110, the liquid medium is cooled by exchanging heat with the refrigerant flowing through the refrigerant flow path (not illustrated). The liquid medium cooled by the utilization-side heat exchanger 110 flows out to the second in-heat-exchange-unit liquidmedium pipe 168, and flows toward the liquidmedium outlet 164. The liquid medium having flowed out of theheat exchange unit 200 from the liquidmedium outlet 164 flows through thesecond connection pipe 424 to flow into the utilization-side equipment 410. - (2-1-5) Casing
- The
casing 190 accommodates various components and various devices of theheat exchange unit 200, including thecompressor 130, the heat-source-side heat exchanger 140, theexpansion mechanism 120, the utilization-side heat exchanger 110, thedrain pan 80, thegas detection sensor 70, and theelectric component box 192. A top surface and side surfaces of theheat exchange unit 200 are surrounded by a top panel and side plates (seeFIG. 13 ). - In a lower part of the casing 190 (see
FIG. 18 ), thedrain pan 80 is arranged. Above thedrain pan 80, the heat-source-side heat exchanger 140 is arranged (seeFIG. 18 ). Further, above thedrain pan 80, the utilization-side heat exchanger 110 is arranged (seeFIG. 18 ). The utilization-side heat exchanger 110 is arranged above the heat-source-side heat exchanger 140 (seeFIG. 18 ). Theexpansion mechanism 120 is arranged above the heat-source-side heat exchanger 140, in a back face side of the casing 190 (seeFIG. 18 ). Theelectric component box 192 is arranged at an upper front face side of the casing 190 (seeFIG. 18 ). Theelectric component box 192 is arranged above the heat-source-side heat exchanger 140 (seeFIG. 18 ). Thecompressor 130 is arranged above the heat-source-side heat exchanger 140. - At least the back face of the
casing 190 is provided with anopening 191 b for maintenance (seeFIG. 18 ). Theopening 191 b of thecasing 190 is closed by a side plate of thecasing 190 normally, that is, during operation of the heatload processing system 201. By removing the side plate of thecasing 190 provided in theopening 191 b of thecasing 190, components and devices inside thecasing 190 can be maintained or replaced. - On the back face of the
casing 190, there are provided a heat-source-side liquid medium inlet and a heat-source-side liquid medium outlet (not illustrated) to which a pipe of the heat-source-side liquid medium is connected. Further, on the back face of thecasing 190, there are provided the liquidmedium inlet 162 connected with thefirst connection pipe 422 and the liquidmedium outlet 164 connected with thesecond connection pipe 424. Although a connection method is not limited, thefirst connection pipe 422 and the liquidmedium inlet 162 are screwed to be connected. Further, although a connection method is not limited, the liquidmedium outlet 164 and thesecond connection pipe 424 are screwed to be connected. Moreover, positions of the heat-source-side liquid medium inlet and the heat-source-side liquid medium outlet, and the liquidmedium inlet 162 and the liquidmedium outlet 164 are not limited to the positions drawn in the figure, and may be changed as appropriate. - (2-1-6) Drain Pan
- The
drain pan 80 is arranged in a lower part of thecasing 190. In particular, in one or more embodiments, thedrain pan 80 is arranged in a lowermost part of thecasing 190. Thedrain pan 80 is arranged below the utilization-side heat exchanger 110. Further, thedrain pan 80 is arranged below the heat-source-side heat exchanger 140. Thedrain pan 80 receives condensation water generated on the utilization-side heat exchanger 110, a pipe through which the liquid medium flows, and the like. When theheat exchange unit 200 is installed outdoors, rainwater or the like also flows into thedrain pan 80. Thedrain pan 80 may have a function as a bottom plate of thecasing 190. - The
drain pan 80 may be arranged lower than: at least a part of the first in-heat-exchange-unit liquidmedium pipe 166 and the second in-heat-exchange-unit liquidmedium pipe 168; therefrigerant pipe 151; and the utilization-side heat exchanger 110. In one or more embodiments, thedrain pan 80 may be arranged so as to surround most of a lower part of theheat exchange unit 200. For example, in top view, thedrain pan 80 covers 80% or more of an area of the heat exchange unit 200 (a bottom area of the casing 190). - A structure of the
drain pan 80 of theheat exchange unit 200 of one or more embodiments is similar to that of thedrain pan 80 of theheat exchange unit 100 of the above-described embodiments, and thus a description thereof will be omitted here in order to avoid redundancy. - (2-1-7) Gas Detection Sensor
- The
gas detection sensor 70 is a sensor that detects the presence or absence of refrigerant gas in the internal space Si of thedrain pan 80. In one or more embodiments, thegas detection sensor 70 may be a sensor that has thedetection element 72, and may detect the presence or absence of refrigerant gas at a place where thedetection element 72 is arranged. Thegas detection sensor 70 is a sensor similar to thegas detection sensor 70 of the above-described embodiments. - Similarly to the above-described embodiments, the
detection element 72 of thegas detection sensor 70 is arranged in the internal space Si of thedrain pan 80 located at the lower part in thecasing 190. Further, similarly to the above-described embodiments, thedetection element 72 may be arranged on alower end 82 ab side of aninclined part 82 a of abottom plate 82 of the drain pan 80 (in one or more embodiments, a rear end side of the bottom plate 82). Further, similarly to the above-described embodiments, thedetection element 72 may be arranged near adrain port 86 a, which is a discharge port for water from the internal space Si of thedrain pan 80. By arranging thedetection element 72 at such a position where refrigerant gas is likely to accumulate, highly reliable refrigerant leakage detection is possible. - However, the position where the
detection element 72 of thegas detection sensor 70 is arranged is not limited to a specific position in the internal space Si of thedrain pan 80, similarly to the above-described embodiments. Alternatively, the position where thedetection element 72 of thegas detection sensor 70 is arranged may be, similarly to the above-described embodiments, a place outside the internal space Si of thedrain pan 80 and where the gas in the internal space Si of thedrain pan 80 can be detected. - Further, similarly to the above-described embodiments, the
detection element 72 of thegas detection sensor 70 may be arranged below the electric component that can be an ignition source. - Note that the electric component that can be an ignition source include an electric component that may generate an electric spark. In one or more embodiments, the electric components that can be an ignition source include: the
electric component 93 such as an electromagnetic switch, a contactor, and a relay, and the inverter board 194 for thecompressor 130, which are accommodated in theelectric component box 192; an electronic expansion valve as an example of theexpansion mechanism 120; and theterminal box 131 of thecompressor 130. Theterminal box 131 of thecompressor 130 is connected with an electric wire (not illustrated) for supply of electric power to a motor 130 a of thecompressor 130. - Further, although it is not mounted on the
heat exchange unit 200 in one or more embodiments, a heater may be arranged in theheat exchange unit 200 when theheat exchange unit 200 is installed in a cold region. Depending on specifications, the heater can be hot enough to be an ignition source. In one or more embodiments, the electric component that can become hot enough to be an ignition source may also be arranged above thedetection element 72 of thegas detection sensor 70. - Moreover, in one or more embodiments, the electric component that can be an ignition source (in one or more embodiments: the
electric components 93 such as an electromagnetic switch, a contactor, and a relay, and the inverter board 194 for thecompressor 130, which are accommodated in theelectric component box 192; an electronic expansion valve as an example of theexpansion mechanism 120; and theterminal box 131 of the compressor 130) may be arranged at a high position of 300 mm or more from the bottom of the casing 190 (seeFIGS. 16 and 17 ). By arranging the electric component that can be an ignition source at such a height position, the possibility of ignition with the electric component in thecasing 190 as the ignition source is reduced even if the refrigerant leaks. - Further, from the viewpoint of maintenance, the
detection element 72 of thegas detection sensor 70 may be arranged in a space near (e.g., adjacent to) theopening 191 b for maintenance, in thecasing 190. The space near theopening 191 b is a space accessible to a worker from theopening 191 b. For example, the space near theopening 191 b may be a space within hand reach from theopening 191 b (for example, a space within 50 cm from theopening 191 b). An arrangement of thedetection element 72 of thegas detection sensor 70 at such a position allows thedetection element 72 to be easily replaced and inspected by removing the side plate of thecasing 190 that closes theopening 191 b. - Further, since the
detection element 72 of thegas detection sensor 70 detects the refrigerant gas, thegas detection sensor 70 may have a structure in which thedetection element 72 is less likely to be immersed even if condensation water accumulates in the internal space Si of thedrain pan 80. For example, similarly to the above-described embodiments, theheat exchange unit 200 may have afloat 88 arranged in the internal space Si of thedrain pan 80, and thedetection element 72 of thegas detection sensor 70 may be attached to anupper surface 88 a of thefloat 88 or aside surface 88 b of thefloat 88. Here, in order to avoid redundancy of description, the description of thefloat 88 will be omitted. - Further, the
detection element 72 of thegas detection sensor 70 may be directly attached to theside wall 84 of thedrain pan 80 or a frame (not illustrated) of thecasing 90. In this case, thedetection element 72 of thegas detection sensor 70 may be arranged at a position that is less likely to be immersed, for example, a position higher than thedrain port 86 a in the internal space Si of thedrain pan 80, as shown by reference numeral 72 a inFIG. 18 . - Meanwhile, for a position of the
detection element 72 of thegas detection sensor 70, a position of the electric component that can be an ignition source, and a positional relationship between thedetection element 72 of thegas detection sensor 70 and the electric component that can be an ignition source, the matters described in (2-4-6) of the above-described embodiments may be applied, as long as there is no contradiction. - (2-1-8) Electric Component Box
- The
electric component box 192 is a case that accommodates various electric components. Theelectric component box 192 accommodates the heat-exchange-unitside control board 195, a power source terminal block (not illustrated), the inverter board 194 for thecompressor 130, and theelectric components 93 such as an electromagnetic switch, a contactor, and a relay (seeFIG. 14 ). Theelectric component 93 need not include all of the electromagnetic switch, the contactor, and the relay, but may include any of the electromagnetic switch, the contactor, and the relay. Note that the electric components accommodated in theelectric component box 192 are not limited to those exemplified, and various electric components are accommodated as needed. - The heat-exchange-unit
side control board 195 has various electric circuits, a microcomputer including a CPU and a memory that stores a program executed by the CPU, and the like. - The heat-exchange-unit
side control board 195 controls an operation of each part of theheat exchange unit 200. - The heat-exchange-unit
side control board 195 is electrically connected to various devices of theheat exchange unit 200. The various devices of theheat exchange unit 200 connected to the heat-exchange-unitside control board 195 include thecompressor 130 and theexpansion mechanism 120. Further, in one or more embodiments, the heat-exchange-unitside control board 195 may transmit a control signal to thepump 160, the heat-source-side pump 520, and the like. Further, the heat-exchange-unitside control board 195 is communicably connected to various sensors provided to theheat exchange unit 200, and receives measured values from the various sensors (not illustrated). The various sensors provided to theheat exchange unit 200 include, but not limited to, for example, a temperature sensor that is provided in the firstrefrigerant pipe 151 a and the thirdrefrigerant pipe 151 c and measures a temperature of a refrigerant, a pressure sensor that is provided in the firstrefrigerant pipe 151 a and measures a pressure of the refrigerant, a temperature sensor that is provided in the first in-heat-exchange-unit liquidmedium pipe 166 and the second in-heat-exchange-unit liquidmedium pipe 168 and measures the temperature of the liquid medium, and the like. Further, the heat-exchange-unitside control board 195 is communicably connected to thegas detection sensor 70 of theheat exchange unit 200. - The heat-exchange-unit
side control board 195 controls an operation of various devices of theheat exchange unit 200 and an operation of thepump 160 and the heat-source-side pump 520, in response to an operation or stop command given from an operation device (not illustrated). Further, the heat-exchange-unitside control board 195 controls an operation of various devices of theheat exchange unit 200 such that the liquid refrigerant is cooled to reach a predetermined target temperature and flows out from the liquidmedium outlet 164 of theheat exchange unit 200. Note that an operating principle of a vapor compression refrigerator is generally well known, and thus a description thereof is omitted here. Further, when thegas detection sensor 70 detects leakage of refrigerant gas, the heat-exchange-unitside control board 195 controls devices such that the various devices of theheat exchange unit 200, thepump 160, and the heat-source-side pump 520 perform a predetermined operation at a time of leakage. - (3-1)
- The
heat exchange unit 200 of the above-described embodiments exchanges heat between the liquid medium sent to the utilization-side equipment 410 and the refrigerant, to perform at least one of cooling and heating of the liquid medium. Theheat exchange unit 200 includes the utilization-side heat exchanger 110 as an example of a heat exchanger, thecasing 190, thedrain pan 80, and thegas detection sensor 70 as an example of a first gas detection sensor. The utilization-side heat exchanger 110 exchanges heat between the flammable refrigerant and the liquid medium. Thecasing 190 accommodates the utilization-side heat exchanger 110. Thedrain pan 80 is arranged below the utilization-side heat exchanger 110, in a lower part of thecasing 190. Thedrain pan 80 has thebottom plate 82 and theside wall 84 extending upward from thebottom plate 82. Thegas detection sensor 70 detects the presence or absence of refrigerant gas in the internal space Si of thedrain pan 80, the internal space Si being located above thebottom plate 82 of thedrain pan 80 and below the upper end part of theside wall 84 of thedrain pan 80. - The refrigerant gas is usually heavier than air. Therefore, when the refrigerant leaks, the leaked refrigerant gas moves downward. Therefore, in this
heat exchange unit 200, leaked refrigerant gas tends to accumulate in thedrain pan 80 that is arranged in the lower part of thecasing 190 and receives dew condensation water generated on the pipe, the heat exchanger, and the like. - Here, highly reliable leakage detection of refrigerant gas is possible by detecting the presence or absence of refrigerant gas in the internal space Si of the
drain pan 80 where leaked refrigerant gas tends to accumulate. - In one or more embodiments, the
gas detection sensor 70 may have, as an example of a first detection element, thedetection element 72 that is arranged in the internal space Si of thedrain pan 80, and detects the presence or absence of the refrigerant gas at a place where thedetection element 72 is arranged. - Here, by arranging the
detection element 72 of thegas detection sensor 70 in the internal space Si of thedrain pan 80 where leaked refrigerant gas tends to accumulate, highly reliable refrigerant leakage detection is possible. - (3-2)
- In the
heat exchange unit 200 of the above-described embodiments, thebottom plate 82 of thedrain pan 80 has theinclined part 82 a that is inclined with respect to a horizontal plane. Thedetection element 72 is arranged on a lower end side of theinclined part 82 a. - Here, since the detection element of the
gas detection sensor 70 is arranged on the lower end side of theinclined part 82 a where the refrigerant gas tends to accumulate, highly reliable refrigerant leakage detection is possible. - (3-3)
- In the
heat exchange unit 200 of the above-described embodiments, at least one of thebottom plate 82 or theside wall 84 of thedrain pan 80 is provided with thedrain port 86 a for discharge of water in the internal space Si of thedrain pan 80. Thedetection element 72 is provided near (e.g., adjacent to) thedrain port 86 a. - Here, since the
detection element 72 of thegas detection sensor 70 is arranged near thedrain port 86 a of thedrain pan 80 that is arranged at a position where water is easily discharged, highly reliable refrigerant leakage detection is possible. - (3-4)
- The
heat exchange unit 200 of the above-described embodiments includes thefloat 88 arranged in the internal space Si of thedrain pan 80. Thedetection element 72 is attached to theupper surface 88 a or theside surface 88 b of thefloat 88. - Here, since the
detection element 72 of thegas detection sensor 70 is attached to theupper surface 88 a or theside surface 88 b of thefloat 88, it is possible to detect refrigerant leakage even when water accumulates in thedrain pan 80. - (3-5)
- In the
heat exchange unit 200 of the above-described embodiments, thecasing 190 is formed with theopening 191 b for maintenance. Thedetection element 72 is arranged in a space near (e.g., adjacent to) theopening 191 b. - Here, since the
detection element 72 of thegas detection sensor 70 is arranged in the space near theopening 191 b for maintenance, thedetection element 72 of thegas detection sensor 70 can be easily inspected or replaced. - The
heat exchange unit 200 of the above-described embodiments does not have apump 160 or a heat-source-side pump 520, but the configuration is not limited thereto. Theheat exchange unit 200 may have thepump 160 and/or the heat-source-side pump 520 arranged inside thecasing 190. - Similarly to Modified example 1B of the above-described embodiments, the
heat exchange unit 200 may further have an auxiliary gas detection sensor having a detection element arranged outside thecasing 90, in addition to thegas detection sensor 70 having the detection element arranged in the internal space Si of thedrain pan 80. Detailed description will be omitted. - In the above-described embodiments, a liquid medium cooled or heated by the
heat exchange unit 200 circulates in the liquidmedium circuit 400, but the configuration is not limited to this. For example, when the cooled or heated liquid medium itself is used directly, the liquid medium sent to the utilization-side equipment 410 (for example, a tank) may be used as it is without circulating in the liquidmedium circuit 400. - Further, similarly, the heat-source-side liquid medium that exchanges heat with the refrigerant circulates in the heat-source-side liquid
medium circuit 500, but the configuration is not limited to this. For example, the heat-source-side liquid medium may be groundwater or warm wastewater. Then, the heatload processing system 201 may not include theheat source equipment 510, and the heat-source-side liquid medium that has exchanged heat with the refrigerant in the heat-source-side heat exchanger 140 may be drained as it is. - Although the disclosure has been described with respect to only a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that various other embodiments may be devised without departing from the scope of the above-described embodiments. Accordingly, the scope of the above-described embodiments should be limited only by the attached claims.
- It is widely applicable and useful for heat exchange units that use flammable refrigerants.
-
-
- 10, 110: utilization-side heat exchanger (heat exchanger)
- 60: pump
- 70: gas detection sensor (first gas detection sensor)
- 72: detection element (first detection element)
- 80: drain pan
- 82: bottom plate
- 82 a: inclined part
- 82 ab: lower end of inclined part
- 84: side wall
- 86 a: drain port
- 88: float
- 88 a: upper surface of float
- 88 b: side surface of float
- 90, 190: casing
- 91 b, 191 b: opening of casing
- 100, 200: heat exchange unit
- 270: additional gas detection sensor (second gas detection sensor)
- 272: detection element (second detection element)
- 410: utilization-side equipment
- A1: pump arrangement area
- A2: refrigerant side area
- Si: internal space
Claims (9)
1.-8. (canceled)
9. A heat exchange unit that performs at least one of a cooling and a heating of a liquid medium that is sent to a utilization side equipment, the heat exchange unit comprising:
a heat exchanger that exchanges heat between a flammable refrigerant and the liquid medium;
a casing that accommodates the heat exchanger;
a drain pan with a bottom plate and a side wall that extends upward from the bottom plate, wherein the drain pan is disposed below the heat exchanger in a lower part of the casing; and
a first gas detection sensor that detects presence or absence of a gas of the refrigerant in an internal space of the drain pan, wherein the internal space is a space within the drain pan that is surrounded by the bottom plate, the side wall, and a virtual plane passing through an upper end part of the side wall.
10. The heat exchange unit according to claim 9 , wherein
the first gas detection sensor has a first detection element disposed in the internal space of the drain pan, and
the first gas detection sensor detects the presence or the absence of the gas of the refrigerant at a place where the first detection element is disposed.
11. The heat exchange unit according to claim 10 , wherein
the bottom plate of the drain pan has an inclined part that is inclined with respect to a horizontal plane, and
the first detection element is arranged on a lower end side of the inclined part.
12. The heat exchange unit according to claim 10 , wherein
at least one of the bottom plate and the side wall of the drain pan includes a drain port that discharges water from the internal space of the drain pan, and
the first detection element is disposed adjacent to the drain port.
13. The heat exchange unit according to claim 10 , further comprising
a float disposed in the internal space of the drain pan, wherein
the first detection element is attached to an upper surface or a side surface of the float.
14. The heat exchange unit according to claim 10 , further comprising
a second gas detection sensor with a second detection element disposed outside the casing, wherein
the second gas detection sensor detects the presence or the absence of the gas of the refrigerant at a place where the second detection element is disposed.
15. The heat exchange unit according to claim 10 , wherein
an opening is formed in the casing, and
the first detection element is disposed in a space adjacent to the opening.
16. The heat exchange unit according to claim 10 , further comprising
a pump that is disposed inside the casing and that sends the liquid medium to the utilization-side equipment, wherein
in plan view, an inside of the casing is sectioned into at least:
a pump arrangement area where the pump is disposed; and
a refrigerant side area where a refrigerant pipe through which the refrigerant flows or the heat exchanger is disposed, and
the first detection element is disposed closer to the refrigerant side area than the pump arrangement area in plan view.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2018-184827 | 2018-09-28 | ||
JP2018184827A JP2020051732A (en) | 2018-09-28 | 2018-09-28 | Heat exchange unit |
PCT/JP2019/037267 WO2020067010A1 (en) | 2018-09-28 | 2019-09-24 | Heat exchange unit |
Publications (1)
Publication Number | Publication Date |
---|---|
US20220003443A1 true US20220003443A1 (en) | 2022-01-06 |
Family
ID=69952165
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US17/280,571 Abandoned US20220003443A1 (en) | 2018-09-28 | 2019-09-24 | Heat exchange unit |
Country Status (5)
Country | Link |
---|---|
US (1) | US20220003443A1 (en) |
EP (1) | EP3859252A4 (en) |
JP (1) | JP2020051732A (en) |
CN (1) | CN112805513A (en) |
WO (1) | WO2020067010A1 (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20220186989A1 (en) * | 2019-09-04 | 2022-06-16 | Daikin Industries, Ltd. | Compressor unit and refrigeration apparatus |
US20230417435A1 (en) * | 2022-06-24 | 2023-12-28 | Trane International Inc. | Climate Control System with Improved Leak Detector |
US11971183B2 (en) | 2019-09-05 | 2024-04-30 | Trane International Inc. | Systems and methods for refrigerant leak detection in a climate control system |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
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JP7390947B2 (en) | 2020-03-23 | 2023-12-04 | 本田技研工業株式会社 | lawn mower |
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JP3523584B2 (en) * | 2000-10-12 | 2004-04-26 | 株式会社 日立インダストリイズ | Heat pump system |
KR20030075391A (en) * | 2002-03-18 | 2003-09-26 | 위니아만도 주식회사 | Apparatus for alramming over flow of drain pan in air conditioner |
JP5464225B2 (en) * | 2012-03-26 | 2014-04-09 | ダイキン工業株式会社 | Air conditioner indoor unit |
US9933192B2 (en) | 2012-12-20 | 2018-04-03 | Mitsubishi Electric Corporation | Air-conditioning apparatus |
JP6183589B2 (en) * | 2013-05-23 | 2017-08-23 | 株式会社ノーリツ | Heat pump water heater |
JP2015175531A (en) * | 2014-03-13 | 2015-10-05 | ダイキン工業株式会社 | Refrigeration device unit |
JP2016075435A (en) * | 2014-10-07 | 2016-05-12 | 日立アプライアンス株式会社 | Indoor unit of air conditioner |
JP6137263B2 (en) * | 2015-09-30 | 2017-05-31 | ダイキン工業株式会社 | Refrigeration system for storage |
JP6065962B1 (en) * | 2015-10-28 | 2017-01-25 | 三菱電機株式会社 | Refrigeration cycle equipment |
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2018
- 2018-09-28 JP JP2018184827A patent/JP2020051732A/en active Pending
-
2019
- 2019-09-24 WO PCT/JP2019/037267 patent/WO2020067010A1/en active Application Filing
- 2019-09-24 CN CN201980063788.1A patent/CN112805513A/en active Pending
- 2019-09-24 EP EP19867489.7A patent/EP3859252A4/en active Pending
- 2019-09-24 US US17/280,571 patent/US20220003443A1/en not_active Abandoned
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WO2002027245A1 (en) * | 2000-09-26 | 2002-04-04 | Daikin Industries, Ltd. | Air conditioner |
WO2010062923A1 (en) * | 2008-11-26 | 2010-06-03 | Delphi Technologies, Inc. | Refrigerant leak detection system |
US20200318887A1 (en) * | 2018-01-12 | 2020-10-08 | Mitsubishi Electric Corporation | Air-conditioning apparatus |
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Publication number | Priority date | Publication date | Assignee | Title |
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US20220186989A1 (en) * | 2019-09-04 | 2022-06-16 | Daikin Industries, Ltd. | Compressor unit and refrigeration apparatus |
US11971183B2 (en) | 2019-09-05 | 2024-04-30 | Trane International Inc. | Systems and methods for refrigerant leak detection in a climate control system |
US20230417435A1 (en) * | 2022-06-24 | 2023-12-28 | Trane International Inc. | Climate Control System with Improved Leak Detector |
Also Published As
Publication number | Publication date |
---|---|
EP3859252A1 (en) | 2021-08-04 |
EP3859252A4 (en) | 2021-11-17 |
WO2020067010A1 (en) | 2020-04-02 |
CN112805513A (en) | 2021-05-14 |
JP2020051732A (en) | 2020-04-02 |
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