EP3859252A1 - Unité d'échange de chaleur - Google Patents

Unité d'échange de chaleur Download PDF

Info

Publication number
EP3859252A1
EP3859252A1 EP19867489.7A EP19867489A EP3859252A1 EP 3859252 A1 EP3859252 A1 EP 3859252A1 EP 19867489 A EP19867489 A EP 19867489A EP 3859252 A1 EP3859252 A1 EP 3859252A1
Authority
EP
European Patent Office
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.)
Withdrawn
Application number
EP19867489.7A
Other languages
German (de)
English (en)
Other versions
EP3859252A4 (fr
Inventor
Toshiyuki Kobayashi
Toshiyuki Momono
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Daikin Industries Ltd
Original Assignee
Daikin Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daikin Industries Ltd filed Critical Daikin Industries Ltd
Publication of EP3859252A1 publication Critical patent/EP3859252A1/fr
Publication of EP3859252A4 publication Critical patent/EP3859252A4/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • 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 of a first aspect 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.
  • a heat exchange unit of a second aspect is the heat exchange unit of the first aspect, in which 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.
  • a heat exchange unit of a third aspect is the heat exchange unit of the second aspect, in which 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.
  • a heat exchange unit of a fourth aspect is a heat exchange unit of the second aspect or the third aspect, in which 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 of a fifth aspect is any of the heat exchange units of the second aspect to the fourth aspect, further including 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 of a sixth aspect is any of the heat exchange units of the second aspect to the fifth aspect, further including 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.
  • a heat exchange unit of a seventh aspect is any of the heat exchange units of the second aspect to the sixth aspect, in which 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 of an eighth aspect is any of the heat exchange units of the second aspect to the seventh aspect, further including 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.
  • a heat exchange unit 100 according to a first embodiment 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 the present embodiment 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 the present embodiment 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 the present embodiment. "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 OD1 to OD3 in FIG. 3 ) as shown in FIG. 3 .
  • the devices OD1 to OD3 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. Specifically, in the heating mode, 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, and 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 95a together with a heat-exchange-unit side control board 95 of the heat exchange unit 100 described later.
  • the control unit 95a 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 100a 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 100a of the heat exchange unit 100.
  • a connection method between the liquid-refrigerant connection pipe 52 and the liquid-side connecting port 100a 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 100b 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 100b 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 100b 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 10a 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 10b 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 10a and the second heat exchanger 10b, 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. Although 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. Alternatively, 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. Although 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. Alternatively, 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 the present embodiment 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 the present embodiment, the heat exchange unit 100 has four first expansion mechanisms 20.
  • the heat exchange unit 100 of the present embodiment has two utilization-side heat exchangers 10 (the first heat exchanger 10a and the second heat exchanger 10b) 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.
  • 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 the present embodiment 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 ).
  • 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 91a for maintenance is provided (see FIG. 6 ). Further, on a back face of the casing 90, an opening 91b for maintenance is provided (see FIG. 9 ).
  • the openings 91a and 91b 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 91a and 91b, components and devices inside the casing 90 can be maintained or replaced.
  • liquid-side connecting ports 100a and four gas-side connecting ports 100b of the heat exchange unit 100 are provided on the front face of the casing 90 (in a lower right part of the casing 90 in FIG. 4 ).
  • 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 100a, the gas-side connecting port 100b, 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. Further, 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 is preferably 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 is arranged so as to surround most of a lower part of the heat exchange unit 100.
  • 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 84a 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 84a 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 84a 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 84a 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 86a (see FIG. 8 ).
  • the drain port 86a 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 82a 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 82a.
  • the inclined part 82a is inclined so as to be lowered from a front side to a rear side, and has an upper end 82aa on the front side and a lower end 82ab 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 86a, and water is easily discharged from the internal space Si of the drain pan 80 through the drain port 86a.
  • the bottom plate 82 of the drain pan 80 need not be entirely inclined with respect to the horizontal plane as in the present embodiment. That is, the bottom plate 82 may have the inclined part 82a 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 10a and the second heat exchanger 10b.
  • first heat exchanger 10a and the second heat exchanger 10b will be described as a description of the utilization-side heat exchanger 10 without distinguishing as the first heat exchanger 10a or the second heat exchanger 10b.
  • 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 10a with a liquid medium flow path in the second heat exchanger 10b.
  • 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 10a, and passes through the liquid medium flow path (not illustrated) in the first heat exchanger 10a to flow out to the in-heat-exchange-unit connection pipe 67.
  • the liquid medium having flowed out from the first heat exchanger 10a 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 10b.
  • the liquid medium having flowed into the second heat exchanger 10b passes through the liquid medium flow path (not illustrated) in the second heat exchanger 10b, 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.
  • 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 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 has a detection element 72, and detects 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 drain pan 80 covers most of the lower part of the heat exchange unit 100, for example, 80% or more of the bottom area of the casing 90 in top view, leaked refrigerant gas tends to accumulate in the internal space Si of the drain pan 80. Therefore, it is preferable that 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 90.
  • the detection element 72 is arranged on the lower end 82ab side of the inclined part 82a of the bottom plate 82 of the drain pan 80 (in the present embodiment, a rear end side of the bottom plate 82). Further, preferably, the detection element 72 is arranged near the drain port 86a, 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 82ab side of the inclined part 82a 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 86a 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 86a, in the vicinity of the side wall 84 on the rear side of the drain pan 80 (on the lower end 82ab side of the inclined part 82a).
  • 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 82ab side of the inclined part 82a (for example, the upper end 82aa side of the inclined part 82a).
  • 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 84a, at a position higher than the upper end part 84a 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 86a of the drain pipe 86.
  • the detection element 72 of the gas detection sensor 70 is preferably 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 61a for supply of electric power to a motor 60a 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. It is preferable that the electric component that can become hot enough to be an ignition source is also arranged above the detection element 72 of the gas detection sensor 70.
  • the detection element 72 of the gas detection sensor 70 is preferably arranged below the liquid-side connecting port 100a and the gas-side connecting port 100b 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 is preferably arranged above the liquid-side connecting port 100a and the gas-side connecting port 100b 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 100a or the gas-side connecting port 100b of the heat exchange unit 100.
  • the electric component that can be an ignition source (in the present embodiment: 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) is 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 is arranged 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 is preferably arranged at the following position.
  • an inside of the casing 90 is sectioned into at least a pump arrangement area A1 where the pump 60 is arranged, and a refrigerant side area A2 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 A1 and the refrigerant side area A2 exist inside the casing 90. As shown in FIG. 8 , the detection element 72 of the gas detection sensor 70 is preferably arranged closer to the refrigerant side area A2 than the pump arrangement area A1.
  • the detection element 72 of the gas detection sensor 70 is preferably arranged in a space near the opening 91b for maintenance, in the casing 90.
  • the space near the opening 91b is a space accessible to a worker from the opening 91b.
  • the space near the opening 91b is a space within hand reach from the opening 91b (for example, a space within 50 cm from the opening 91b).
  • the detection element 72 of the gas detection sensor 70 detects the refrigerant gas, it is preferable 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 has a float 88 that is arranged in the internal space Si of the drain pan 80, and the detection element 72 is attached to an upper surface 88a or a side surface 88b 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 88a 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 88b (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 86a, the gas refrigerant can be detected by the gas detection sensor 70 when the refrigerant leaks.
  • 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 is preferably arranged at a position that is less likely to be immersed, for example, a position higher than the drain port 86a in the internal space Si of the drain pan 80, as shown by reference numeral 72a 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 95a 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 95a controls an operation of each unit of the heat load processing system 1.
  • the control unit 95a 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 95a 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 95a 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 95a is communicably connected to the gas detection sensor 70 of the heat source unit 300.
  • the control unit 95a 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 95a 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 95a 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 95a 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 embodiment 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 has, 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 82a that is inclined with respect to a horizontal plane.
  • the detection element 72 is arranged on a lower end side of the inclined part 82a.
  • the detection element of the gas detection sensor 70 is arranged on the lower end side of the inclined part 82a 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 86a for discharge of water in the internal space Si of the drain pan 80.
  • the detection element 72 is provided near the drain port 86a.
  • 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 86a 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 embodiment 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 88a or the side surface 88b of the float 88.
  • the detection element 72 of the gas detection sensor 70 is attached to the upper surface 88a or the side surface 88b 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 91b for maintenance.
  • the detection element 72 is arranged in a space near the opening 91b.
  • the detection element 72 of the gas detection sensor 70 is arranged in the space near the opening 91b 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 embodiment 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 A1 and the refrigerant side area A2 in plan view.
  • the pump arrangement area A1 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 A2 than the pump arrangement area A1 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 embodiment 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 is preferably 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 is preferably 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 ).
  • the detection element 272 of the auxiliary gas detection sensor 270 is preferably arranged near the floor surface FL of the machine room R.
  • the detection element 272 of the auxiliary gas detection sensor 270 is preferably 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 for example, a tank
  • a heat exchange unit 200 according to a second embodiment 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 the present embodiment are similar to the liquid medium and the refrigerant described in the first embodiment. The description is omitted here.
  • the heat-source-side liquid medium used in the present embodiment 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 first embodiment. However, in the second embodiment, 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 400A in the second embodiment is similar to the liquid medium circuit 400 of the first embodiment except for the fact that a pump 160 (a device similar to the pump 60 of the first embodiment) 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 first embodiment
  • 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 400A 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. In 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 151a 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 151b 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 151b.
  • the refrigerant pipe 151 includes a third refrigerant pipe 151c 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 first embodiment.
  • 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 151b, 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 151b, the third refrigerant pipe 151c, 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 151b 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 151c.
  • 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. Atop 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 191b for maintenance (see FIG. 18 ).
  • the opening 191b 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 is preferably 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 is 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 the second embodiment is similar to that of the drain pan 80 of the heat exchange unit 100 of the first embodiment, 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 is a sensor that has the detection element 72, and detects 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 first embodiment.
  • 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 first embodiment, the detection element 72 is preferably arranged on a lower end 82ab side of an inclined part 82a of a bottom plate 82 of the drain pan 80 (in the present embodiment, a rear end side of the bottom plate 82). Further, similarly to the first embodiment, the detection element 72 is preferably arranged near a drain port 86a, 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 first embodiment.
  • the position where the detection element 72 of the gas detection sensor 70 is arranged may be, similarly to the first embodiment, 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 is preferably 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 130a 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. It is preferable that the electric component that can become hot enough to be an ignition source is also arranged above the detection element 72 of the gas detection sensor 70.
  • the electric component that can be an ignition source (in the present embodiment: 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) is 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 is arranged 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 is preferably arranged in a space near the opening 191b for maintenance, in the casing 190.
  • the space near the opening 191b is a space accessible to a worker from the opening 191b.
  • the space near the opening 191b is a space within hand reach from the opening 191b (for example, a space within 50 cm from the opening 191b).
  • the detection element 72 of the gas detection sensor 70 detects the refrigerant gas, it is preferable to 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 preferably has 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 is preferably attached to an upper surface 88a of the float 88 or a side surface 88b 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 is preferably arranged at a position that is less likely to be immersed, for example, a position higher than the drain port 86a in the internal space Si of the drain pan 80, as shown by reference numeral 72a 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. Further, it is preferable that the heat-exchange-unit side control board 195 can transmit a control signal to the pump 160, the heat-source-side pump 520, and the like. Further, 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 151a and the third refrigerant pipe 151c and measures a temperature of a refrigerant, a pressure sensor that is provided in the first refrigerant pipe 151a 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. Further, 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 embodiment 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 has, 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 82a that is inclined with respect to a horizontal plane.
  • the detection element 72 is arranged on a lower end side of the inclined part 82a.
  • the detection element of the gas detection sensor 70 is arranged on the lower end side of the inclined part 82a 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 86a for discharge of water in the internal space Si of the drain pan 80.
  • the detection element 72 is provided near the drain port 86a.
  • the detection element 72 of the gas detection sensor 70 is arranged near the drain port 86a 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 embodiment 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 88a or the side surface 88b of the float 88.
  • the detection element 72 of the gas detection sensor 70 is attached to the upper surface 88a or the side surface 88b 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 191b for maintenance.
  • the detection element 72 is arranged in a space near the opening 191b.
  • the detection element 72 of the gas detection sensor 70 is arranged in the space near the opening 191b 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 embodiment 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 for example, a tank
  • 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.
  • Patent Literature 1 WO 2014/97440 A

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Sustainable Development (AREA)
  • Other Air-Conditioning Systems (AREA)
  • Heat-Pump Type And Storage Water Heaters (AREA)
  • Cooling Or The Like Of Electrical Apparatus (AREA)
EP19867489.7A 2018-09-28 2019-09-24 Unité d'échange de chaleur Withdrawn EP3859252A4 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2018184827A JP2020051732A (ja) 2018-09-28 2018-09-28 熱交換ユニット
PCT/JP2019/037267 WO2020067010A1 (fr) 2018-09-28 2019-09-24 Unité d'échange de chaleur

Publications (2)

Publication Number Publication Date
EP3859252A1 true EP3859252A1 (fr) 2021-08-04
EP3859252A4 EP3859252A4 (fr) 2021-11-17

Family

ID=69952165

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19867489.7A Withdrawn EP3859252A4 (fr) 2018-09-28 2019-09-24 Unité d'échange de chaleur

Country Status (5)

Country Link
US (1) US20220003443A1 (fr)
EP (1) EP3859252A4 (fr)
JP (1) JP2020051732A (fr)
CN (1) CN112805513A (fr)
WO (1) WO2020067010A1 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU2019464673B2 (en) * 2019-09-04 2023-11-02 Daikin Europe N.V. Compressor unit and refrigeration apparatus
US11231198B2 (en) 2019-09-05 2022-01-25 Trane International Inc. Systems and methods for refrigerant leak detection in a climate control system
JP7390947B2 (ja) 2020-03-23 2023-12-04 本田技研工業株式会社 芝刈機
US20230417435A1 (en) * 2022-06-24 2023-12-28 Trane International Inc. Climate Control System with Improved Leak Detector

Family Cites Families (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1161570C (zh) * 2000-09-26 2004-08-11 大金工业株式会社 空调机
JP3523584B2 (ja) * 2000-10-12 2004-04-26 株式会社 日立インダストリイズ ヒートポンプシステム
KR20030075391A (ko) * 2002-03-18 2003-09-26 위니아만도 주식회사 에어컨 드레인 팬의 과수위 경보장치
US8695404B2 (en) * 2008-11-26 2014-04-15 Delphi Technologies, Inc. Refrigerant leak detection system
JP5464225B2 (ja) * 2012-03-26 2014-04-09 ダイキン工業株式会社 空気調和装置の室内機
WO2014097440A1 (fr) 2012-12-20 2014-06-26 三菱電機株式会社 Dispositif de climatisation
JP6183589B2 (ja) * 2013-05-23 2017-08-23 株式会社ノーリツ ヒートポンプ給湯装置
JP2015175531A (ja) * 2014-03-13 2015-10-05 ダイキン工業株式会社 冷凍装置ユニット
JP2016075435A (ja) * 2014-10-07 2016-05-12 日立アプライアンス株式会社 空気調和機の室内機
JP6137263B2 (ja) * 2015-09-30 2017-05-31 ダイキン工業株式会社 収納庫用の冷凍システム
JP6065962B1 (ja) * 2015-10-28 2017-01-25 三菱電機株式会社 冷凍サイクル装置
DE112018006844B4 (de) * 2018-01-12 2023-10-19 Mitsubishi Electric Corporation Klimaanlage

Also Published As

Publication number Publication date
WO2020067010A1 (fr) 2020-04-02
US20220003443A1 (en) 2022-01-06
EP3859252A4 (fr) 2021-11-17
CN112805513A (zh) 2021-05-14
JP2020051732A (ja) 2020-04-02

Similar Documents

Publication Publication Date Title
EP3859252A1 (fr) Unité d'échange de chaleur
EP3998443B1 (fr) Unité intérieure d'équipement de réfrigération
US9377211B2 (en) Outdoor unit and air-conditioning apparatus
JP6336121B2 (ja) 冷凍サイクル装置
CN110226071B (zh) 空调装置
US11536502B2 (en) Refrigerant cycle apparatus
JP6785961B2 (ja) ヒートポンプ利用機器
JP2011122767A (ja) 空気調和機および空気調和機の冷媒量検出方法
EP2416078B1 (fr) Dispositif de climatisation
WO2020067039A1 (fr) Unité d'échange de chaleur
EP3859248B1 (fr) Unité d'échange de chaleur
EP3657097B1 (fr) Congélateur
JPWO2018092197A1 (ja) 空気調和装置および冷媒漏洩検知方法
JP3882841B2 (ja) 空気調和装置、熱源ユニット、及び空気調和装置の更新方法
US20220290885A1 (en) Air conditioning system
JP2006220342A (ja) 空気調和装置
JP7494504B2 (ja) ヒートポンプ装置
US20170067675A1 (en) Accumulator and refrigeration cycle apparatus
JP2020051733A (ja) 熱交換ユニット
JP2020143800A (ja) 冷媒サイクル装置
CN113574330B (zh) 制冷剂循环系统以及方法

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20210420

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

A4 Supplementary search report drawn up and despatched

Effective date: 20211020

RIC1 Information provided on ipc code assigned before grant

Ipc: F24F 11/36 20180101ALI20211014BHEP

Ipc: F25B 25/00 20060101ALI20211014BHEP

Ipc: F25B 13/00 20060101ALI20211014BHEP

Ipc: F24F 13/22 20060101ALI20211014BHEP

Ipc: F24F 13/20 20060101ALI20211014BHEP

Ipc: F24F 5/00 20060101ALI20211014BHEP

Ipc: F25B 1/00 20060101ALI20211014BHEP

Ipc: F24F 1/36 20110101ALI20211014BHEP

Ipc: F24F 1/20 20110101ALI20211014BHEP

Ipc: F25B 49/02 20060101AFI20211014BHEP

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20220628

RAP3 Party data changed (applicant data changed or rights of an application transferred)

Owner name: DAIKIN INDUSTRIES, LTD.

P01 Opt-out of the competence of the unified patent court (upc) registered

Effective date: 20230525

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20240131