JP2020051733A - Heat exchange unit - Google Patents

Abstract

To provide a heat exchange unit of high safety capable of reducing a risk of firing due to an electrical apparatus of the heat exchange unit as an ignition source, the heat exchange unit utilizing a combustible refrigerant.SOLUTION: A heat exchange unit 100 executes cooling and heating of a liquid medium by exchanging heat between the liquid medium fed to use-side equipment and a combustible refrigerant supplied from a heat source unit. The heat exchange unit includes a use-side heat exchanger 10 exchanging heat between the refrigerant and the liquid medium, communication piping connection portions 100a, 100b, unit inner piping which connects the communication piping connection portion and the use-side heat exchanger and in which the refrigerant flows, electric components 20, 61, 93 which may become ignition sources, and a casing housing the use-side heat exchanger and the electric components which may become ignition sources. The communication piping connection portion is connected with communication piping which connects the heat exchange unit and the heat source unit and in which the refrigerant flows. The electric components which may become the ignition sources, are disposed above the communication piping connection portion.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a heat exchange unit that performs cooling / heating of a liquid medium by exchanging heat between a liquid medium sent to a use-side facility and a refrigerant.

  2. Description of the Related Art Conventionally, there has been known a heat exchange unit that performs cooling / heating of a liquid medium by exchanging heat between a liquid medium and a refrigerant sent to a use-side facility. For example, Patent Document 1 (International Publication No. 2014/97440) discloses a heat exchanger that cools brine or the like with a refrigerant in a heat exchanger disposed in a repeater, and sends the cooled brine or the like to a user-side facility. A replacement unit is disclosed.

  By the way, in this heat exchange unit, a flammable (including slightly flammable) refrigerant may be used in consideration of various characteristics of the refrigerant. However, when the flammable refrigerant is used in the heat exchange unit, if the refrigerant leaks for some reason, there is a possibility that the electric device in the casing accommodating the heat exchanger may ignite as an ignition source.

  Therefore, in the heat exchange unit using the flammable refrigerant, measures are required to reduce the possibility of ignition using the electric device in the casing of the heat exchange unit as an ignition source even when the refrigerant leaks. .

  The heat exchange unit of the first aspect is configured to exchange heat between the liquid medium sent to the use-side equipment and the flammable refrigerant supplied from the heat source-side device, so that at least cooling and heating of the liquid medium are performed. Do one. The heat exchange unit includes a heat exchanger, a communication pipe connection, a pipe in the unit, an electric component that can be an ignition source, and a casing. In the heat exchanger, heat exchange is performed between the refrigerant and the liquid medium. The communication pipe connection section connects the heat exchange unit and the heat source side device, and is connected to a communication pipe through which a refrigerant flows. The piping in the unit connects the connection piping connection portion and the heat exchanger, and the refrigerant flows inside. The casing houses a heat exchanger and electrical components that can be a source of ignition. An electric component that can be an ignition source is disposed above the connection portion of the communication pipe.

  The refrigerant gas is usually heavier than air, and when the refrigerant leaks, the leaked refrigerant gas moves downward. In this heat exchange unit, electric components that can be an ignition source are arranged above the connection pipe connection portion that can be a leakage point of the refrigerant, so that even if the refrigerant leaks, the electric device in the casing is regarded as the ignition source. The possibility of ignited ignition is reduced.

  A heat exchange unit according to a second aspect is the heat exchange unit according to the first aspect, wherein an electric component that can be an ignition source is arranged at a position higher than the bottom of the casing by 300 mm or more.

  Here, the electric components are arranged at a position higher than the bottom of the casing by 300 mm or more from the bottom side of the casing where the refrigerant gas which is heavier than the air easily accumulates. Therefore, even if the refrigerant leaks, the possibility of ignition is easily reduced.

  The heat exchange unit according to a third aspect is the heat exchange unit according to the first aspect or the second aspect, and further includes a gas detection sensor. The gas detection sensor has a detection element disposed below the connection pipe connection portion, and detects the presence or absence of refrigerant gas at the location where the detection element is disposed.

  Here, by arranging the detection element of the gas detection sensor below the connection pipe connection portion, it is possible to detect the leakage of the refrigerant gas even at the time of refrigerant leakage, and to reduce the possibility of ignition.

  A heat exchange unit according to a fourth aspect is the heat exchange unit according to any one of the first aspect to the third aspect, and further includes a pump. The pump has a motor and a terminal box to which electric wires for supplying electric power to the motor are connected. The pump is located inside the casing. The pump sends the liquid medium to the usage-side equipment. Electrical components that can be a source of ignition include the terminal box of the pump.

  The heat exchange unit according to a fifth aspect is the heat exchange unit according to any one of the first aspect to the fourth aspect, wherein the electrical component that can be an ignition source includes at least one of an electromagnetic switch, a contactor, and a relay. including.

It is a perspective view of a heat exchange unit concerning a 1st embodiment. FIG. 2 is a schematic configuration diagram of a heat load processing system including the heat exchange unit of FIG. 1. FIG. 2 is a schematic plan view of a machine room as a place where the heat exchange unit of FIG. 1 is installed. It is a schematic front view of the heat exchange unit of FIG. FIG. 2 is a schematic plan view of a lower stage inside a casing of the heat exchange unit of FIG. 1. FIG. 2 is a schematic front view of the heat exchange unit of FIG. 1 with a side plate of a casing removed. FIG. 2 is a schematic right side view of the heat exchange unit of FIG. 1 with a side plate of a casing removed. It is a schematic plan view of the drain pan of the heat exchange unit of FIG. FIG. 9 is a schematic rear view of a part of the casing of the heat exchange unit of FIG. 1 and a drain pan of FIG. 8. It is a schematic right side view of the drain pan of FIG. FIG. 9 is a diagram schematically illustrating an example of a float installed in an internal space of the drain pan in FIG. 8. FIG. 9 is a diagram schematically illustrating another example of the float installed in the internal space of the drain pan in FIG. 8. It is a schematic front view of the heat exchange unit of modification 1B. It is a specific example of the refrigerant | coolant used by the heat exchange unit of 1st Embodiment and 2nd Embodiment.

  Hereinafter, an embodiment of the heat exchange unit will be described.

(1) Overall Configuration A heat exchange unit 100 according to the 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. In FIG. 2, the internal configuration is drawn only for one of the four heat source units 300, and the drawing of the other three internal configurations is omitted. FIG. 3 is a schematic plan view of the machine room R in which 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 the lower stage inside the casing 90 of the heat exchange unit 100. FIG. 6 is a schematic front view of the heat exchange unit 100 with the side plate of the casing 90 removed. FIG. 7 is a schematic right side view of the heat exchange unit 100 with the side plate of the casing 90 removed.

  In the following description, expressions indicating directions such as “up”, “down”, “left”, “right”, “front (front)”, and “rear (back)” may be used. Unless otherwise specified, these directions are indicated by arrows in the drawing.

  The heat load processing system 1 mainly includes the heat exchange unit 100, the heat source unit 300, and the use-side equipment 410.

  The heat exchange unit 100 is a unit that performs at least one of cooling and heating of the liquid medium by exchanging heat between the liquid medium and the refrigerant. In particular, 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 the liquid refrigerant in the heat exchange unit 100 is sent to the use-side facility 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 the brine is, for example, an aqueous sodium chloride solution, an aqueous calcium chloride solution, an aqueous ethylene glycol solution, an aqueous propylene glycol solution, or the like. The liquid medium is not limited to the types exemplified here, and may be appropriately selected. In the present embodiment, it is assumed that brine is used as the liquid medium.

  In the present embodiment, the refrigerant is a flammable refrigerant. Here, the flammable refrigerant includes Class 3 (strongly flammable), Class 2 (lowly flammable), and Subclass 2L according to the standard of ASHRAE34 Designation and safety classification of refrigerant in the United States or the standard of ISO817 Refrigerants-Designation and safety classification. (Flammable). For example, FIG. 13 shows a specific example of the refrigerant used in the present embodiment. In FIG. 13, “ASHRAE Number” is the Ashley number of the refrigerant defined by ISO817, “Component” is the Ashley number of the substance contained in the refrigerant, and “% by mass” is the mass percent concentration of each substance contained in the refrigerant. , “Alternative” indicates the name of the substance of the refrigerant that is often replaced by the refrigerant. In the present embodiment, the refrigerant used is R32. Note that the refrigerant illustrated in FIG. 13 has a feature that the density is higher than that of air.

  The heat exchange unit 100 is not limited to an installation place, but is installed, for example, indoors. In the present embodiment, 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. The devices OD1 to OD3 include, but are not limited to, for example, a boiler, a generator, a switchboard, and the like. However, only the heat exchange unit 100 may be installed in the machine room R. Further, the heat exchange unit 100 may be installed outdoors, such as on the roof of a building or around a building.

  The heat source unit 300 is a device that cools or heats a refrigerant using air as a heat source. The heat source unit 300 is connected to the heat exchange unit 100 via the liquid refrigerant communication pipe 52 and the gas refrigerant communication pipe 54, and forms a refrigerant circuit 50 together with the heat exchange unit 100. The refrigerant circuit 50 includes 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, and a use side heat exchanger 10 of the heat exchange unit 100, which will be described later. It mainly has the first expansion mechanism 20 and the like. The heat source unit 300 is not limited to an installation place, but is installed, for example, on a rooftop or around a building.

  In the present embodiment, the heat load processing system 1 has four heat source units 300 (see FIG. 2). The heat exchange unit 100 cools / heats the liquid medium with the refrigerant cooled / heated in the four heat source units 300. However, the number of the heat source units 300 is an example, and the number is not limited to four. The number of heat source units 300 may be one to three, or five or more.

  The use-side facility 410 is a facility that uses or stores the liquid medium that has been cooled / heated by the heat exchange unit 100. The use-side equipment 410 is connected to the heat exchange unit 100 via the liquid medium communication pipe 420, and forms the liquid medium circuit 400. In the liquid medium circuit 400, a liquid medium sent by a pump 60 of the heat exchange unit 100 described below circulates.

  The usage-side equipment 410 is, for example, an air handling unit or a fan coil unit that performs air conditioning by exchanging heat between a liquid medium cooled / heated by the heat exchange unit 100 and air. However, the usage-side facility 410 may be a manufacturing apparatus that performs cooling / heating of a manufacturing apparatus or a product by using a liquid medium cooled / heated by the heat exchange unit 100. Further, the usage-side facility 410 may be a tank that stores the liquid medium cooled / heated by the heat exchange unit 100. The liquid medium stored in the tank as the use-side equipment 410 is sent to, for example, a device using the liquid medium by a pump (not shown) or the like.

  FIG. 2 shows only one use-side facility 410. However, the heat load processing system 1 includes a plurality of use-side facilities, and the liquid medium cooled / heated by the heat exchange unit 100 may be sent to the plurality of use-side facilities. When the heat load processing system 1 includes a plurality of use-side facilities, the types of the use-side facilities may all be the same, or the use-side facilities may include a plurality of types of facilities.

(2) Detailed Configuration Details of the heat source unit 300, the liquid refrigerant communication pipe 52 and the gas refrigerant communication pipe 54, the liquid medium circuit 400, and the heat exchange unit 100 will be described.

(2-1) Heat Source Unit The heat source unit 300 will be described with reference to FIG. In FIG. 2, the internal configuration is drawn only for one of the four heat source units 300, and the drawing of the other three internal configurations is omitted. The heat source unit 300 from which drawing is omitted has the same configuration as the heat source unit 300 described below.

The heat source unit 300 mainly includes a unit refrigerant pipe 350, a compressor 330, a flow path switching mechanism 332, a heat source side heat exchanger 340, a second expansion mechanism 344, a fan 342, a gas side shutoff valve 304, and a liquid side shutoff valve. 302 and a heat source side control board 395.
(See FIG. 2).

(2-1-1) In-unit piping The in-unit refrigerant piping 350 includes a compressor 330, a flow path switching mechanism 332, a heat source side heat exchanger 340, a second expansion mechanism 344, a gas side shutoff valve 304, and a liquid side shutoff. This is a pipe connecting between the components of the heat source unit 300 including the 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 shown) of the compressor 330 and the flow path switching mechanism 332. An accumulator (not shown) is provided in the suction pipe 351. The discharge pipe 352 is a pipe that connects a discharge port (not shown) of the compressor 330 and the flow path switching mechanism 332. The first gas side pipe 353 is a pipe connecting the flow path switching mechanism 332 and the gas side of the heat source side heat exchanger 340. The liquid side pipe 354 is a pipe connecting the liquid side of the heat source side heat exchanger 340 and the liquid side closing valve 302. A second expansion mechanism 344 is arranged in the liquid side pipe 354. The second gas side pipe 355 is a pipe connecting the flow path switching mechanism 332 and the gas side closing valve 304.

(2-1-2) Compressor The compressor 330 sucks low-pressure refrigerant in the refrigeration cycle through the suction pipe 351, compresses the refrigerant by a compression mechanism (not shown), and discharges the refrigerant through the discharge pipe 352. And discharges high-pressure refrigerant in the refrigeration cycle after compression.

  The compressor 330 is, for example, a scroll-type compressor. However, the type of the compressor 330 is not limited to the scroll type, but may be a compressor of a screw type, a rotary type, or the like. The compressor 330 is, for example, a compressor with a variable capacity, but may be a compressor with a constant capacity.

(2-1-3) Channel Switching Mechanism The channel switching mechanism 332 is a mechanism that switches the flow direction of the refrigerant in the refrigerant circuit 50 according to the operation mode of the heat load processing system 1. The operation modes of the heat load processing system 1 include a mode for cooling the liquid medium (hereinafter, referred to as a cooling mode) and a mode for heating the liquid medium (hereinafter, referred to as a heating mode).

  In the present embodiment, the flow path switching mechanism 332 is a four-way switching valve. However, the flow path switching mechanism 332 is not limited to the four-way switching valve, and is configured to realize the following switching of the flow direction of the refrigerant by combining a plurality of solenoid valves and piping. Is also good.

  In the cooling mode, the flow path switching mechanism 332 switches the flow direction of the refrigerant in the refrigerant circuit 50 so that the refrigerant discharged from the compressor 330 is sent to the heat source side heat exchanger 340. Specifically, in the cooling mode, the flow path switching mechanism 332 makes the suction pipe 351 communicate with the second gas-side pipe 355 and makes the discharge pipe 352 communicate with the first gas-side pipe 353 (see FIG. 2). (See the solid line in the path switching mechanism 332).

  In the heating mode, the flow path switching mechanism 332 switches the flow direction of the refrigerant in the refrigerant circuit 50 so that the refrigerant discharged from the compressor 330 is sent to the use side heat exchanger 10 of the heat exchange unit 100. Specifically, in the heating mode, the flow path switching mechanism 332 makes the suction pipe 351 communicate with the first gas side pipe 353 and makes the discharge pipe 352 communicate with the second gas side pipe 355 (flow in FIG. 2). (See the broken line in the path switching mechanism 332).

(2-1-4) Heat-source-side heat exchanger The heat-source-side heat exchanger 340 is a heat exchanger that exchanges heat between the air around the heat-source unit 300 and the refrigerant flowing inside the heat-source-side heat exchanger 340. . The heat source side heat exchanger 340 is not limited to a type, but is, for example, a cross-fin type fin-and-tube heat exchanger. The heat source side heat exchanger 340 functions as a condenser (radiator) when the operation mode of the heat load processing system 1 is in the cooling mode. Further, when the operation mode of the heat load processing system 1 is in the heating mode, the heat source side heat exchanger 340 functions as an evaporator.

(2-1-5) Second Expansion Mechanism The second expansion mechanism 344 is a mechanism that expands the refrigerant flowing through the liquid-side pipe 354 to adjust the pressure and flow rate of the refrigerant. In the present embodiment, the second expansion mechanism 344 is an electronic expansion valve whose opening degree can be adjusted. The second expansion mechanism 344 is not limited to an electronic expansion valve. The second expansion mechanism 344 may be an automatic temperature expansion valve having a temperature-sensitive cylinder, or may be a capillary tube.

(2-1-6) Fan The fan 342 is a mechanism that generates an airflow so that air passes through the heat source side heat exchanger 340 in order to promote heat exchange between the refrigerant and the air in the heat source side heat exchanger 340. is there. The type of the fan 342 is not limited, but is, for example, a propeller fan.

(2-1-7) Liquid-side shut-off valve The liquid-side shut-off valve 302 is a valve that switches communication / non-communication between the liquid refrigerant communication pipe 52 and the liquid-side pipe 354. A liquid refrigerant communication pipe 52 is connected to one end of the liquid-side stop valve 302, and a liquid-side pipe 354 is connected to the other end of the liquid-side stop valve 302 (see FIG. 2).

(2-1-8) Gas-side shut-off valve The gas-side shut-off valve 304 is a valve that switches communication / non-communication between the gas refrigerant communication pipe 54 and the second gas-side pipe 355. A gas refrigerant communication pipe 54 is connected to one end of the gas-side stop valve 304, and a second gas-side pipe 355 is connected to the other end of the gas-side stop valve 304 (see FIG. 2).

(2-1-9) Heat source side control board 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 section 95a will be described later.

  The heat source side control board 395 has various electric circuits, a microcomputer including a CPU and a memory storing a program executed by the CPU, and the like.

(2-2) Refrigerant communication pipe (2-2-1) Liquid refrigerant communication pipe The liquid refrigerant communication pipe 52 connects the liquid side closing valve 302 of the heat source unit 300 and the liquid side connection port 100a of the heat exchange unit 100. Then, the liquid side pipe 354 of the heat source unit 300 communicates with the liquid side pipe 56 in the heat exchange unit 100 of the heat exchange unit 100. The connection between the liquid refrigerant communication pipe 52 and the liquid side connection port 100a of the heat exchange unit 100 uses, for example, a flare joint. However, the connection method between the liquid refrigerant communication pipe 52 and the liquid-side connection port 100a of the heat exchange unit 100 is not limited to a connection method using a flare joint, for example, a connection method using a flange joint, A brazed connection may be selected.

(2-2-2) Gas refrigerant communication pipe The gas refrigerant communication pipe 54 connects the gas side closing valve 304 of the heat source unit 300 and the gas side connection port 100b of the heat exchange unit 100, and The gas side pipe 355 communicates with the gas side pipe 58 in the heat exchange unit of the heat exchange unit 100. The gas refrigerant communication pipe 54 and the gas-side connection port 100b of the heat exchange unit 100 are connected, for example, by brazing. However, the connection method between the gas refrigerant communication pipe 54 and the gas-side connection 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.

(2-3) Liquid Medium Circuit The liquid medium circuit 400 is a circuit in which the liquid medium circulates. The liquid medium circuit 400 is configured such that the use side heat exchanger 10 of the heat exchange unit 100 and the use side equipment 410 are connected by piping.

  In the liquid medium circuit 400, the use side heat exchanger 10 and the pump 60 of the heat exchange unit 100, the use side equipment 410, the first liquid medium pipe 66 in the heat exchange unit, and the second liquid medium pipe in the heat exchange unit. 68, a communication pipe 67 in the heat exchange unit, a first communication pipe 422, and a second communication pipe 424.

  The use side heat exchanger 10 and the pump 60 of the heat exchange unit 100 will be described later.

  As described above, the use-side facility 410 is, for example, an air handling unit or a fan coil unit. Further, as described above, the use-side facility 410 may be a manufacturing apparatus that performs cooling / heating of a manufacturing apparatus or a product by using a liquid medium cooled / heated by the heat exchange unit 100, A tank for storing the liquid medium cooled / heated by the exchange unit 100 may be used.

  The first liquid medium pipe 66 in the heat exchange unit is a pipe that connects the liquid medium inlet 62 of the heat exchange unit 100 and the use side heat exchanger 10 (particularly, a first heat exchanger 10a described later). The pump 60 is disposed in the first liquid medium pipe 66 in the heat exchange unit.

  The second liquid medium pipe 68 in the heat exchange unit is a pipe that connects the use-side heat exchanger 10 (particularly, a second heat exchanger 10b described later) and the liquid medium outlet 64 of the heat exchange unit 100.

  The communication pipe 67 in the heat exchange unit is a pipe that connects a first heat exchanger 10a and a second heat exchanger 10b described later.

  The first communication pipe 422 is a pipe that connects the use-side facility 410 and the liquid medium inlet 62 of the heat exchange unit 100. Although the connection method is not limited, the first communication pipe 422 is connected to, for example, the liquid medium inlet 62 of the heat exchange unit 100 by a flange joint. The first communication pipe 422 may be connected to the liquid medium inlet 62 of the heat exchange unit 100 by screwing or by welding.

  The second communication pipe 424 is a pipe that connects the liquid medium outlet 64 of the heat exchange unit 100 and the use-side equipment 410. Although the connection method is not limited, the second communication pipe 424 is connected to the liquid medium outlet 64 of the heat exchange unit 100 by a flange joint, for example. The second communication pipe 424 may be connected to the liquid medium outlet 64 of the heat exchange unit 100 by screwing or by welding.

  When the pump 60 is operated, the liquid medium flows through the liquid medium circuit 400 as follows.

  The liquid medium flowing out of the use-side facility 410 flows through the first communication pipe 422 toward the liquid medium inlet 62 of the heat exchange unit 100. The liquid medium flowing into the heat exchange unit 100 from the liquid medium inlet 62 passes through the first liquid medium pipe 66 in the heat exchange unit and flows into the use side heat exchanger 10. When passing through the use-side heat exchanger 10, the liquid medium is cooled / heated by exchanging heat with the refrigerant flowing through the refrigerant circuit 50. The liquid medium cooled / heated by the use side heat exchanger 10 flows out of the use side heat exchanger 10 and flows through the second liquid medium pipe 68 in the heat exchange unit toward the liquid medium outlet 64. The liquid medium flowing out of the heat exchange unit 100 from the liquid medium outlet 64 flows through the second communication pipe 424 and flows into the use-side equipment 410.

(2-4) Heat Exchange Unit The heat exchange unit 100 is a unit that performs at least one of cooling and heating of the liquid medium by exchanging heat between the liquid medium and the refrigerant sent to the use-side facility 410. . As described above, the heat exchange unit 100 of the present embodiment is a unit that performs both cooling and heating of the liquid medium by exchanging heat between the liquid medium and the refrigerant that are sent to the use-side facility 410. .

  When the heat exchange unit 100 is a unit only for cooling the liquid medium, the heat source unit 300 may not have the flow path switching mechanism 332. When the heat exchange unit 100 is a unit only for heating the liquid medium, particularly, the refrigerant discharged from the compressor 330 is supplied to the heat source side heat exchanger 340 and adheres to the heat source side heat exchanger 340. When the reverse cycle defrost operation for defrosting the frost is not performed, the heat source unit 300 may not have the above-described flow path switching mechanism 332.

  The heat exchange unit 100 mainly includes a casing 90, a drain pan 80, a use side heat exchanger 10, a first expansion mechanism 20, a pump 60, a gas detection sensor 70, and an electric component box 92 ( 4 to 7).

  The heat exchange unit 100 has the same number of the first expansion mechanisms 20 as the heat source units 300 (the same number as the refrigerant circuits 50 formed by the heat source units 300 and the heat exchange units 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 use-side heat exchangers 10 (a first heat exchanger 10a and a second heat exchanger 10b) connected in series in the liquid medium circuit 400. However, the number of the use side heat exchangers 10 is an example, and is not limited to two. For example, the heat exchange unit 100 may include the same number (here, four) of use-side heat exchangers 10 as the heat source units 300 connected in series in the liquid medium circuit 400. Further, for example, the heat exchange unit 100 has only one use-side heat exchanger 10, and the use-side heat exchanger 10 is connected to all (here, four) heat source units 300, and The same number of refrigerant circuits 50 may be configured. Further, heat exchange unit 100 may include a plurality of use-side heat exchangers 10 connected in parallel in liquid medium circuit 400.

  Further, the heat exchange unit 100 of the present embodiment has one pump 60. However, the present invention is not limited to this, and the heat exchange unit 100 may include a plurality of pumps 60 connected in series or in parallel in the liquid medium circuit 400.

(2-4-1) Casing The casing 90 includes various components of the heat exchange unit 100, including the drain pan 80, the use side heat exchanger 10, the first expansion mechanism 20, the pump 60, the gas detection sensor 70, and the electric component box 92. And various equipment. The casing 90 also accommodates electrical components (an electrical component 93 accommodated in an electrical component box 92, a terminal box 61 of the pump 60, an electronic expansion valve as an example of the first expansion mechanism 20, and the like) that can be an ignition source described later. Is done. The top and side surfaces of the heat exchange unit 100 are surrounded by a top plate and side plates (see FIG. 1).

  A drain pan 80 is disposed at a lower portion in the casing 90 (see FIG. 6). Above the drain pan 80, the use-side heat exchanger 10 and the pump 60 are arranged (see FIG. 6). The first expansion mechanism 20 is disposed in front of the use side heat exchanger 10 and near the upper end of the use side heat exchanger 10 (see FIG. 6). The electric component box 92 is arranged on the upper front side of the casing 90 (see FIG. 7). The electric component box 92 is disposed above the use side heat exchanger 10 and the pump 60 (see FIG. 6).

  An opening 91a for maintenance is provided on the front surface of the casing 90 (see FIG. 6). An opening 91b for maintenance is provided on the rear surface of the casing 90 (see FIG. 9). The openings 91a and 91b of the casing 90 are normally closed by the side plates of the casing 90, that is, during operation of the heat load processing system 1. By removing the side plate of the casing 90 provided in the openings 91a and 91b, maintenance and replacement of components and devices inside the casing 90 can be performed.

  The liquid-side connection port 100a and the gas-side connection port 100b of the heat exchange unit 100 are provided at four locations on the front surface of the casing 90 (the lower right part of the casing 90 in FIG. 4). The liquid side connection port 100a is an example of a connection pipe connection portion to which the liquid refrigerant communication pipe 52 is connected. The gas-side connection port 100b is another example of the communication pipe connection portion to which the gas refrigerant communication pipe 54 is connected. The liquid refrigerant communication pipe 52 and the gas refrigerant communication pipe 54 connect between the heat exchange unit 100 and the heat source unit 300, and the refrigerant flows inside. A liquid refrigerant communication pipe 52 is connected to each liquid side connection port 100a (see FIG. 2). A gas refrigerant communication pipe 54 is connected to each gas side connection port 100b (see FIG. 2). A liquid medium inlet 62 and a liquid medium outlet 64 of the heat exchange unit 100 are provided on the rear surface of the casing 90 (see FIGS. 5 and 7). The first communication pipe 422 is connected to the liquid medium inlet 62 (see FIG. 2). The second communication pipe 424 is connected to the liquid medium outlet 64 (see FIG. 2).

  The positions of the liquid side connection port 100a, the gas side connection port 100b, the liquid medium inlet 62, and the liquid medium outlet 64 are not limited to the positions drawn in the drawings, and may be changed as appropriate.

(2-4-2) Drain Pan The drain pan 80 will be described with reference to FIGS.

  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. FIG. 10 is a schematic right side view of the drain pan 80.

  The drain pan 80 is arranged below the casing 90. In particular, in the present embodiment, the drain pan 80 is arranged at the lowermost part of the casing 90. The drain pan 80 is arranged below the use side heat exchanger 10. The drain pan 80 is disposed below the pump 60. The drain pan 80 receives the condensed water generated in the use side heat exchanger 10, the pump 60, the pipe through which the liquid medium and the refrigerant flow, and the like. When the heat exchange unit 100 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 90.

  The drain pan 80 has a bottom plate 82 and a side wall 84. The bottom plate 82 is substantially rectangular in plan view (see FIGS. 8 to 10). The side wall 84 extends upward from the outer peripheral edge of the bottom plate 82 (see FIGS. 9 and 10).

  The space formed above the bottom plate 82 of the drain pan 80 and below the upper end 84a of the side wall 84 of the drain pan 80 is referred to as the internal space Si of the drain pan 80 here. The condensed water that has dropped into the internal space Si of the drain pan 80 is temporarily received in the internal space Si, and is discharged from a drain port provided in the drain pan 80. The drain port is an opening for discharging 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. In the present embodiment, a drain pipe 86 is attached to a side wall 84 disposed on the rear side of the drain pan 80 so as to communicate with the internal space Si of the drain pan 80, and an end of the drain pipe 86 on the internal space Si side is a drain port. 86a (see FIG. 8). The drain port 86a is provided at the center of the side wall 84 arranged on the rear side of the drain pan 80. In other words, the drain pipe 86 is attached to the 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 portion of the side wall 84 arranged on the rear side of the drain pan 80 (see FIG. 9).

  In the present embodiment, the drain pan 80 is provided with only one drain port. However, the present invention is not limited to this, and drain ports may be provided at a plurality of locations. The drain port does not need to be formed by a pipe fixed to the bottom plate 82 and the side wall 84 of the drain pan 80, and may be formed as a drain port by simply forming a hole in the bottom plate 82 and the side wall 84 of the drain pan 80.

  The bottom plate 82 of the drain pan 80 has an inclined portion 82a inclined with respect to a horizontal plane. In particular, in the present embodiment, the entire bottom plate 82 is inclined with respect to the horizontal plane, and the entire bottom plate 82 functions as the inclined portion 82a. In the present embodiment, the inclined portion 82a is inclined so as to become lower from the front side to the rear side, and has an upper end 82aa on the front side and a lower end 82ab on the rear side (see FIG. 10). That is, in the present embodiment, the bottom plate 82 is lowered toward the side wall 84 disposed on the rear side of the drain pan 80 provided with the drain port 86a, and water is discharged from the internal space Si of the drain pan 80 through the drain port 86a. Easy to be discharged.

  The bottom plate 82 of the drain pan 80 does not need to be entirely inclined with respect to the horizontal plane as in the present embodiment. That is, the bottom plate 82 may have the inclined portion 82a only in a part. For example, in the region of the bottom plate 82 of the drain pan 80 where the condensed water is unlikely to fall, the inclination may not be provided.

(2-4-3) User-side heat exchanger The user-side heat exchanger 10 includes a first heat exchanger 10a and a second heat exchanger 10b.

  In the following description, features common to the first heat exchanger 10a and the second heat exchanger 10b will not be referred to as the first heat exchanger 10a or the second heat exchanger 10b, but will be referred to as user-side heat exchange. This will be described as a description of the container 10.

  In the use-side heat exchanger 10, heat exchange is performed between the refrigerant and the liquid medium. In the present embodiment, the use-side heat exchanger 10 is a plate-type heat exchanger. However, the type of the use side heat exchanger 10 is not limited to the plate type heat exchanger, and a type of heat exchanger that can be used for the heat exchanger between the refrigerant and the liquid medium may be appropriately selected. .

  The first heat exchanger 10a and the second heat exchanger 10b are connected to two heat exchange unit internal liquid side pipes 56 and two heat exchange unit internal gas side pipes 58, respectively. The liquid-side pipe 56 in the heat exchange unit connects the liquid-side connection port 100a and the use-side heat exchanger 10, and is an example of a pipe in the unit in which a refrigerant flows. The gas-side pipe 58 in the heat exchange unit connects the gas-side connection port 100b and the use-side heat exchanger 10, and is an example of a pipe in the unit in which a refrigerant flows. Further, a first liquid medium pipe 66 in the heat exchange unit and a communication pipe 67 in the heat exchange unit are connected to the first heat exchanger 10a. The communication pipe 67 in the heat exchange unit and the second liquid medium pipe 68 in the heat exchange unit are connected to the second heat exchanger 10b. The communication pipe 67 in the heat exchange unit is a pipe that communicates a liquid medium flow path (not shown) in the first heat exchanger 10a with a liquid medium flow path in the second heat exchanger 10b.

  When the pump 60 is operated, the liquid medium flows into the first heat exchanger 10a through the first communication pipe 422 and the first liquid medium pipe 66 in the heat exchange unit, and flows into the first heat exchanger 10a. After passing through a liquid medium flow path (not shown), it flows out to the communication pipe 67 in the heat exchange unit. The liquid medium flowing out of the first heat exchanger 10a to the communication pipe 67 in the heat exchange unit passes through the communication pipe 67 in the heat exchange unit and flows into the second heat exchanger 10b. The liquid medium flowing into the second heat exchanger 10b passes through a liquid medium flow path (not shown) in the second heat exchanger 10b, and further, a second liquid medium pipe 68 and a second communication pipe in the heat exchange unit. After passing through 424, the liquid is sent to the use-side facility 410.

  When the operation mode of the heat load processing system 1 is in the cooling mode, each of the use side heat exchangers 10 is provided with a refrigerant flow path (shown in the figure) from the heat exchange unit internal liquid side pipe 56 to each of the use side heat exchangers 10. )). The liquid medium flowing in the liquid medium flow path (not shown) in each use side heat exchanger 10 exchanges heat with the refrigerant flowing in the refrigerant flow path (not shown) in each use side heat exchanger 10. Cooled. The refrigerant that has flowed through the refrigerant flow path (not shown) in each use side heat exchanger 10 flows into the gas side pipe 58 in the heat exchange unit, passes through the gas refrigerant communication pipe 54, and It flows into the second gas side pipe 355.

  On the other hand, when the operation mode of the heat load processing system 1 is in the heating mode, the refrigerant flow path in each of the use side heat exchangers 10 (from the gas side pipe 58 in the heat exchange unit) to each of the use side heat exchangers 10. (Not shown). The liquid medium flowing in the liquid medium flow path (not shown) in each use side heat exchanger 10 exchanges heat with the refrigerant flowing in the refrigerant flow path (not shown) in each use side heat exchanger 10. Is done. The refrigerant that has flowed through the refrigerant flow path (not shown) in each use-side heat exchanger 10 flows into the liquid-side pipe 56 in the heat exchange unit, passes through the liquid refrigerant communication pipe 52, and passes through the liquid in the heat source unit 300. It flows into the side pipe 354.

(2-4-4) First Expansion Mechanism The first expansion mechanism 20 is a mechanism that expands the refrigerant flowing through the liquid side pipe 56 in the heat exchange unit and adjusts the pressure and flow rate of the refrigerant.

  In the present embodiment, the first expansion mechanism 20 is an electronic expansion valve whose opening can be adjusted. The electronic expansion valve as the first expansion mechanism 20 is arranged in front of the use side heat exchanger 10 and near the upper end of the use side heat exchanger 10. The first expansion mechanism 20 is not limited to an electronic expansion valve. The first expansion mechanism 20 may be a temperature automatic expansion valve having a temperature-sensitive cylinder, or may be a capillary tube.

(2-4-5) Pump The pump 60 is a pump that sends the liquid medium to the use-side equipment 410. The pump 60 is disposed in the first liquid medium pipe 66 in the heat exchange unit.

  The pump 60 is, for example, a constant-speed spiral pump. However, the pump 60 is not limited to the centrifugal pump, and the type of the pump 60 may be appropriately selected. Further, the pump 60 may be a variable flow rate pump.

  In the present embodiment, the pump 60 is disposed upstream of the use side heat exchanger 10 in the flow direction of the liquid medium in the liquid medium circuit 400, in other words, in the first liquid medium pipe 66 in the heat exchange unit. ing. However, the present invention is not limited to this. The pump 60 is connected to the second liquid medium pipe 68 in the heat exchange unit in the flow direction of the liquid medium in the liquid medium circuit 400 on the downstream side of the use side heat exchanger 10. , May be arranged.

(2-4-6) Gas detection sensor The gas detection sensor 70 is a sensor that has the detection element 72 and detects the presence or absence of refrigerant gas at the location where the detection element 72 is arranged.

  The detection element 72 is, for example, a semiconductor sensor element. The electrical conductivity of a semiconductor sensing element changes between a state where there is no refrigerant gas and a state where there is a refrigerant gas. The gas detection sensor 70 includes a detection circuit (not shown) that is electrically connected to the detection element 72, and detects a change in the electrical conductivity of the detection element 72 by the detection circuit. The presence or absence of the refrigerant gas in the place where it is performed is detected.

  However, the detection element 72 is not limited to a semiconductor-type element, and may be any element that can detect a refrigerant gas. For example, the gas detection sensor 70 includes an infrared light source (not shown) and an infrared detection element as the detection element 72, and electrically detects the change in the amount of infrared light detected by the detection element 72 that varies depending on the presence or absence of the refrigerant gas. The presence or absence of the refrigerant gas at the location where the detection element 72 is disposed may be detected by the detection by the connected detection circuit.

  As described above, since the refrigerant gas has a higher density than air, when the refrigerant leaks in the heat exchange unit 100, the refrigerant gas easily moves to a lower position. Therefore, it is preferable that the detection element 72 of the gas detection sensor 70 is disposed in the internal space Si of the drain pan 80 located at the lower part in the casing 90. Preferably, the sensing element 72 is disposed on the lower end 82ab side of the inclined portion 82a of the bottom plate 82 of the drain pan 80 (in this embodiment, on the rear end side of the bottom plate 82). Preferably, sensing element 72 is arranged near drain 86a, which is an outlet for water from internal space Si of drain pan 80.

  In the present embodiment, the detection element 72 of the gas detection sensor 70 is disposed in the inner space Si of the drain pan 80 and on the lower end 82ab side of the inclined portion 82a (see FIG. 10). The detection element 72 of the gas detection sensor 70 is arranged at a position adjacent to a drain port 86a provided on a side wall 84 on the rear side of the drain pan 80 (see FIGS. 8 to 10). By arranging the detection element 72 at a position where such refrigerant gas easily accumulates, highly reliable refrigerant leak detection is possible.

  In addition, the position where the detection element 72 of the gas detection sensor 70 is disposed is an example, and is not limited to the position drawn with the reference numeral 72 in FIGS. 8 to 10.

  For example, the position where the detection element 72 of the gas detection sensor 70 is arranged is near the side wall 84 on the rear side of the drain pan 80 (on the lower end 82ab side of the inclined portion 82a) and may be located away from the drain port 86a. Good.

  Further, for example, when a location where the possibility of leakage of the refrigerant gas is relatively high is specified, the detection element 72 of the gas detection sensor 70 is the internal space Si of the drain pan 80, and the refrigerant gas is It may be arranged near a place where the possibility of leakage is relatively high. At this time, the detection element 72 of the gas detection sensor 70 may be arranged at a place other than the lower end 82ab of the inclined portion 82a (for example, at the upper end 82aa of the inclined portion 82a). For example, the detection element 72 of the gas detection sensor 70 may be disposed in the internal space Si of the drain pan 80 and near the liquid-side connection port 100a and the gas-side connection port 100b.

  Further, for example, the position where the detection element 72 of the gas detection sensor 70 is disposed is higher than the upper end portion 84a of the side wall 84 of the drain pan 80 (in the casing 90, as shown by reference numeral 72b in FIG. 9). 80 above the internal space Si).

  In addition, it is preferable that the detection element 72 of the gas detection sensor 70 is disposed below an electric component that can be an ignition source regardless of whether or not the detection element 72 is disposed in the internal space Si of the drain pan 80 (see FIGS. 6 and 6). (See FIG. 7). By arranging the detection element 72 below the electric component that can be the ignition source, even when the refrigerant leaks in the heat exchange unit 100, the refrigerant gas can be supplied from the bottom side of the casing 90 to the electric source that can be the ignition source. Leakage of the refrigerant is likely to be detected before reaching the height position of the component.

  In addition, the electric component which can be an ignition source includes an electric component which may generate an electric spark. In the present embodiment, the electrical components that can be the ignition source include electrical components 93 such as an electromagnetic switch, a contactor, and a relay housed in an electrical component box 92 described later, and an electronic component as an example of the first expansion mechanism 20. It includes an expansion valve and a terminal box 61 of the pump 60. An electric wire 61 a for supplying electric power to a motor 60 a of the pump 60 is connected to the terminal box 61 of the pump 60.

  Although the heat exchange unit 100 is not installed in the heat exchange unit 100 of the present embodiment, when the heat exchange unit 100 is installed in a cold region, a heater may be arranged in the heat exchange unit 100. is there. Depending on its specifications, the heater may be hot enough to be a source of ignition. It is also preferable that such an electrical component that can be heated to such a degree as to become an ignition source is disposed above the detection element 72 of the gas detection sensor 70.

  Further, it is preferable that the detection element 72 of the gas detection sensor 70 is disposed below the liquid-side connection port 100a and the gas-side connection port 100b of the heat exchange unit 100, which has a relatively high possibility of a leakage point of the refrigerant ( 6 and 7). On the other hand, the electric components that can be the ignition source as described above are arranged above the liquid-side connection port 100a and the gas-side connection port 100b of the heat exchange unit 100. With such an arrangement, even when the refrigerant leaks at the liquid-side connection port 100a or the gas-side connection port 100b of the heat exchange unit 100, the height of the electrical component that can serve as an ignition source from the bottom side of the casing 90 even when the refrigerant gas leaks. It is easy to detect the leakage of the refrigerant before reaching the position.

  Preferably, an electric component that can serve as an ignition source (in the present embodiment, an electric component 93 such as an electromagnetic switch, a contactor, and a relay housed in an electric component box 92, and an example of the first expansion mechanism 20). The electronic expansion valve and the terminal box 61 of the pump 60 are arranged at a height of 300 mm or more from the bottom of the casing 90 (see FIGS. 6 and 7). By arranging an electric component that can be an ignition source at such a height position, the possibility of ignition using the electric component in the casing 90 as an ignition source is reduced even when the refrigerant leaks. .

  More preferably, the electric component that can be an ignition source is arranged at a position higher than the bottom of the casing 90 by 300 mm or more, and the detection element 72 of the gas detection sensor 70 is higher than the position 300 mm above the bottom of the casing 90. It is placed in a lower position. With such an arrangement, even when the refrigerant leaks in the heat exchange unit 100, the leakage of the refrigerant is detected before the refrigerant gas reaches the height position of the electric component that can be an ignition source from the bottom side of the casing 90. Easy to be.

  When the refrigerant leaks, the refrigerant is likely to leak from the refrigerant pipe 57 including the use side heat exchanger 10 and the liquid side pipe 56 in the heat exchange unit and the gas side pipe 58 in the heat exchange unit. The detection element 72 of the detection sensor 70 is preferably arranged at the following position.

  The interior of the casing 90 is at least divided into a pump arrangement area A1 where the pump 60 is arranged and a refrigerant side area A2 where the refrigerant pipe 57 or the use side heat exchanger 10 is arranged, in a plan view. (See FIGS. 5 and 8). That is, in the 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 to the pump arrangement area A1.

  Further, from the viewpoint of maintenance, the detection element 72 of the gas detection sensor 70 is preferably arranged in a space near the maintenance opening 91b of the casing 90. Note that the space in the vicinity of the opening 91b is a space accessible by an operator from the opening 91b. For example, the space in the vicinity of the opening 91b is a space that can be reached from the opening 91b (for example, a space within 50 cm from the opening 91b). If the detection element 72 of the gas detection sensor 70 is disposed at such a position, the replacement and inspection of the detection element 72 can be easily performed by removing the side plate of the casing 90 closing the opening 91b.

  Further, since the detection element 72 of the gas detection sensor 70 detects refrigerant gas, even if condensed water accumulates in the internal space Si of the drain pan 80, the detection element 72 is disposed at a position where it is difficult for the detection element 72 to be flooded. It is preferable to be configured as follows.

  For example, it is preferable that the heat exchange unit 100 has a float 88 that is disposed in the internal space Si of the drain pan 80 and has the upper surface 88a or the side surface 88b to which the detection element 72 is attached. The float 88 is a member configured to float on the water surface when condensed water accumulates in the internal space Si of the drain pan 80.

  More specifically, the structure of the float 88 will be described. For example, specifically, the float 88 is swingably supported by a main body 881 and a support portion (not shown) provided on a side wall 84 of the drain pan 80 or a frame (not shown) of the casing 90. And a swing shaft 882 (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 (the upper surface of the main body 881) as shown in FIG. 11A, or the side surface 88b of the float 88 (the upper surface of the main body 881) as shown in FIG. 11B. Side). When there is no water in the drain pan 80, the main body 881 of the float 88 is located at the 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 a solid line in FIGS. 11A and 11B. On the other hand, when water accumulates in the drain pan 80, the main body 881 of the float 88 swings around the swing shaft 882 and floats by buoyancy as shown by the two-dot chain line in FIGS. 11A and 11B. With such a configuration, even when condensed water accumulates in the internal space Si of the drain pan 80, the infiltration of the detection element 72 of the gas detection sensor 70 is easily suppressed. Therefore, even when 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 at the time of refrigerant leakage.

  Note that the heat exchange unit 100 may 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 a frame (not shown) of the casing 90. At this time, the detection element 72 of the gas detection sensor 70 is disposed at a position where it is difficult to be flooded, for example, in the internal space Si of the drain pan 80 as shown by reference numeral 72a in FIG. Is preferred.

(2-4-7) Electrical Component Box The electrical component box 92 is a case that accommodates various electrical components. The electric component box 92 houses a heat exchange unit side control board 95 and a power supply terminal block (not shown). The electric component box 92 accommodates electric components 93 such as an electromagnetic switch, a contactor, and a relay. The electric component 93 does not need to include all of the electromagnetic switch, the contactor, and the relay, and may include any of the electromagnetic switch, the contactor, and the relay. In addition, the electric components accommodated in the electric component box 92 are not limited to those illustrated, and various electric components are accommodated as necessary.

  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 CPU, and a microcomputer including a memory in which a program executed by the CPU is stored.

  The control unit 95a controls the 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. Various devices of the heat source unit 300 and the heat exchange unit 100 connected to the control unit 95a include the compressor 330 of the heat source unit 300, the flow path switching mechanism 332, the second expansion mechanism 344, the fan 342, and the heat exchange unit 100. The first expansion mechanism 20 and the pump 60 are included. The control unit 95a is communicably connected to various sensors included in the heat source unit 300 and the heat exchange unit 100, and receives measurement values from various sensors (not shown). Various sensors included in the heat exchange unit 100 include, but are not limited to, for example, a temperature sensor that measures the temperature of a refrigerant provided in the liquid side pipe 56 in the heat exchange unit and the gas side pipe 58 in the heat exchange unit, The pressure sensor provided in the liquid side pipe 56 in the heat exchange unit, the liquid provided in the first liquid medium pipe 66 in the heat exchange unit, the communication pipe 67 in the heat exchange unit, and the second liquid medium pipe 68 in the heat exchange unit It includes a temperature sensor for measuring the temperature of the medium. Further, various sensors included in the heat source unit 300 are not limited, and for example, a temperature sensor provided in the suction pipe 351 for measuring a suction temperature and a temperature sensor provided in the discharge pipe 352 for measuring a discharge temperature And a pressure sensor for measuring the discharge pressure. Further, the control unit 95a is communicably connected to the gas detection sensor 70 of the heat source unit 300.

  The control unit 95a controls operations of various devices of the heat source unit 300 and the heat exchange unit 100 according to a run / stop command given from an operation device (not shown). Further, the control unit 95a controls the state of the flow path switching mechanism 332 of the heat source unit 300 according to the operation mode (cooling mode / heating mode) of the heat load processing system 1. Further, the control unit 95a controls the heat source unit 300 and the various devices of the heat exchange unit 100 so that the liquid refrigerant is cooled / heated to a predetermined target temperature and flows out of the liquid medium outlet 64 of the heat exchange unit 100. Control behavior. Note that the principle of operation of the vapor compression refrigerator is generally well known, and thus the description thereof is omitted here. Further, when leakage of the refrigerant gas is detected by the gas detection sensor 70, the control unit 95a controls various devices such that the various devices of the heat source unit 300 and the heat exchange unit 100 perform predetermined leakage operations.

(3) Features (3-1)
The heat exchange unit 100 of the above embodiment exchanges heat between the liquid medium sent to the use-side facility 410 and the refrigerant supplied from the heat source unit 300 as an example of the heat source-side device. At least one of cooling and heating. The heat exchange unit 100 includes a use-side heat exchanger 10 as an example of a heat exchanger, a liquid-side connection port 100a and a gas-side connection port 100b as an example of a connection pipe connection portion, and heat as an example of unit piping. The unit includes a liquid-side pipe 56 in the exchange unit and a gas-side pipe 58 in the heat exchange unit, an electric component that can be an ignition source, and a casing 90. In the use side heat exchanger 10, heat exchange is performed between the combustible refrigerant and the liquid medium. The liquid refrigerant communication pipe 52 is connected to the liquid side connection port 100a. The gas refrigerant connection pipe 54 is connected to the gas side connection port 100b. The liquid refrigerant communication pipe 52 and the gas refrigerant communication pipe 54 connect the heat exchange unit 100 and the heat source unit 300 and are examples of communication pipes through which the refrigerant flows. The liquid side pipe 56 in the heat exchange unit connects the liquid side connection port 100a and the use side heat exchanger 10, and the refrigerant flows inside. The gas side pipe 58 in the heat exchange unit connects the gas side connection port 100b and the use side heat exchanger 10, and the refrigerant flows inside. The casing 90 houses the use-side heat exchanger 10 and electric components that can be a source of ignition. The electrical components that can be the ignition source are arranged above the liquid side connection port 100a and the gas side connection port 100b.

  In the present embodiment, the electric components that can be the ignition source include the electric component 93, for example. The electric component 93 includes at least one of an electromagnetic switch, a contactor, and a relay. In the present embodiment, the electric component 93 is housed in the electric component box 92. In the present embodiment, the electrical components that can be the ignition source include the terminal box 61 of the pump 60. An electric wire 61 a for supplying electric power to a motor 60 a of the pump 60 is connected to the terminal box 61 of the pump 60. In the present embodiment, the electric components that can be the ignition source include an electronic expansion valve as an example of the first expansion mechanism 20.

  The heat exchange unit 100 does not need to include all of the illustrated electrical components that can be the ignition source, and may include some of them. In addition, the heat exchange unit 100 includes an electric component that can be an ignition source other than the illustrated one, in addition to the electric component that can be the illustrated ignition source, or instead of the electric component that can be the exemplified ignition source. Is also good. For example, when the pump 60 has a variable flow rate, the electrical components that can be a source of ignition may include an inverter board for the pump 60 housed in the electrical component box 92.

  As described above, the refrigerant gas is heavier than the air, and when the refrigerant leaks, the leaked refrigerant gas moves downward. In the present heat exchange unit 100, electric components that can be an ignition source are disposed above the liquid-side connection port 100a and the gas-side connection port 100b that can be leakage points of the refrigerant. It is possible to reduce the possibility of ignition using the internal electric equipment as an ignition source.

(3-2)
In the heat exchange unit 100 of the above embodiment, the electric component that can be an ignition source is arranged at a position that is higher than the bottom of the casing 90 by 300 mm or more.

  Here, the electric components are arranged at a position higher than the bottom of the casing 90 by which the refrigerant gas, which is heavier than air, easily accumulates, by 300 mm or more.

  Further, by setting the reference value to a relatively small value of 300 mm, it is possible to reduce the possibility of ignition at the time of refrigerant leakage and to avoid an increase in the size of the heat exchange unit 100 (the casing 90).

(3-3)
The heat exchange unit 100 according to the third aspect includes a gas detection sensor 70. The gas detection sensor 70 has a detection element 72 disposed below the liquid-side connection port 100a and the gas-side connection port 100b, and detects the presence or absence of refrigerant gas at the location where the detection element 72 is disposed.

  Here, by arranging the detection element 72 of the gas detection sensor 70 below the liquid-side connection port 100a and the gas-side connection port 100b, even when the refrigerant leaks, the leakage of the refrigerant gas is detected, and the possibility of ignition is suppressed. be able to.

(4) Modification (4-1) Modification 1A
The heat exchange unit 100 of the above embodiment has the pump 60, but is not limited to this. The pump 60 may be installed outside the casing 90 separately from the heat exchange unit 100.

(4-2) Modification 1B
The heat exchange unit 100 includes a gas having a detection element 272 disposed outside the casing 90 in addition to the gas detection sensor 70 disposed in the casing 90 or instead of the gas detection sensor 70 disposed in the casing 90. A detection sensor 270 may be provided (see FIG. 12).

  The gas detection sensor 270 is a sensor that detects the presence or absence of refrigerant gas at the location where the detection element 272 is disposed. The gas detection sensor 270 is the same as the gas detection sensor 70 except for where the detection element 272 is installed.

  Since the heat exchange unit 100 includes the gas detection sensor 270, even when the refrigerant gas flows out of the casing 90, the refrigerant gas can be detected by the gas detection sensor 270, and the safety is high.

  Since the refrigerant gas has a higher density than air as described above, the detection element 272 of the gas detection sensor 270 is located near the floor surface FL of the unit installation space (for example, the machine room R) where the heat exchange unit 100 is installed. Preferably, they are arranged. For example, it is preferable that the sensing element 272 be disposed at a position lower than the height of 300 mm above the floor surface FL of the machine room R. For example, the heat exchange unit 100 may be installed on a foundation (base) 2 provided on the floor FL in the machine room R (see FIG. 12). In such a case, the detection element 272 of the gas detection sensor 270 is preferably arranged near the floor FL of the machine room R. The detection element 272 of the gas detection sensor 270 is preferably arranged at a height of up to 300 mm above the floor surface FL of the machine room R. At this time, the detection element 272 of the gas detection sensor 270 may be arranged at a position lower than the bottom of the casing 90 of the heat exchange unit 100 as shown in FIG.

(4-3) Modification 1C
In the above embodiment, the liquid medium cooled / heated by the heat exchange unit 100 circulates through the liquid medium circuit 400, but is not limited to this. For example, when the cooled / heated liquid medium itself is directly used, the liquid medium sent to the use-side facility 410 (for example, a tank) may be used as it is without circulating through the liquid medium circuit 400. Good.

(4-4) Modification 1D
In the above embodiment, the heat source side heat exchanger 340 of the heat source unit 300 is a heat exchanger that exchanges heat between the air around the heat source unit 300 and the refrigerant flowing inside the heat source side heat exchanger 340. However, the present invention is not limited to this. For example, the heat source side heat exchanger 340 of the heat source unit 300 may be a heat exchanger that performs heat exchange between a liquid medium (for example, cooling water or hot water) and a refrigerant flowing inside the heat source side heat exchanger 340.

  Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure described in the claims. .

  It is widely applicable and useful for a heat exchange unit using a flammable refrigerant.

10. User side heat exchanger (heat exchanger)
20 First expansion mechanism (electric parts)
52 Liquid refrigerant connection pipe (connection pipe)
54 Gas refrigerant communication pipe (communication pipe)
56 Liquid side piping in heat exchange unit (unit piping)
58 Gas side piping in heat exchange unit (unit piping)
60 pump 60a motor 61 terminal box (electrical parts)
61a Electric wire 70, 270 Gas detection sensor 72, 272 Detection element 90 Casing 93 Electric component 100 Heat exchange unit 100a Liquid side connection port (communication pipe connection part)
100b Gas side connection port (communication pipe connection)
300 heat source unit (heat source side device)
410 User-side equipment

International Publication No. WO 2014/97440

Claims (5)

At least one of cooling and heating of the liquid medium is performed by exchanging heat between the liquid medium sent to the use-side equipment (410) and the flammable refrigerant supplied from the heat source-side device (300). A heat exchange unit to perform,
A heat exchanger (10) in which heat is exchanged between the refrigerant and the liquid medium;
A communication pipe connection part (100a, 100b) that connects between the heat exchange unit and the heat source side device and is connected to a communication pipe (52, 54) through which the refrigerant flows;
A pipe in a unit (56, 58) for connecting the connection pipe connection portion and the heat exchanger, and through which the refrigerant flows;
Electrical components (20, 61, 93) that can be ignition sources;
A casing (90) for housing the heat exchanger and the electrical components;
With
The electrical component is disposed above the communication pipe connection portion,
Heat exchange unit (100). The electric component is disposed at a position higher than the bottom of the casing by 300 mm or more.
The heat exchange unit according to claim 1. A gas detection sensor (70, 270) having a detection element (72, 272) disposed below the connection pipe connection part and detecting the presence or absence of the refrigerant gas at a location where the detection element is disposed. Further prepare,
The heat exchange unit according to claim 1. It has a motor (60a) and a terminal box (61) to which an electric wire (61a) for supplying electric power to the motor is connected. The terminal box is disposed inside the casing, and the liquid medium is sent to the use-side equipment. And a pump (60) for feeding the liquid with
The electric component includes the terminal box,
The heat exchange unit according to claim 1. The electrical component includes at least one of an electromagnetic switch, a contactor, and a relay,
The heat exchange unit according to claim 1.

Images