CN112752939A

CN112752939A - Thermal load handling system

Info

Publication number: CN112752939A
Application number: CN201980063690.6A
Authority: CN
Inventors: 小林俊幸; 桃野俊之
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2018-09-28
Filing date: 2019-09-24
Publication date: 2021-05-04
Also published as: EP3859253A1; JP2020051738A; US20210348820A1; EP3859253A4; WO2020067041A1

Abstract

A countermeasure against leakage of refrigerant is provided. A heat load processing system (100) is provided with a plurality of machine units (R1) having a plurality of Refrigerant Circuits (RC), a housing (50) that houses a plurality of machine units (R1) that form different Refrigerant Circuits (RC), refrigerant leakage detection units (70, 84) that individually detect refrigerant leakage in each Refrigerant Circuit (RC), and a controller (80). The equipment unit (R1) includes, as equipment constituting one Refrigerant Circuit (RC), a heat exchanger (33) connected to refrigerant pipes (Pb, Pc) and heat medium pipes (Hb, Hc, Hd). When the refrigerant leakage detecting section detects a refrigerant leakage, the controller (80) executes a refrigerant leakage circuit determining process for determining a Refrigerant Circuit (RC) in which a refrigerant leakage is occurring (refrigerant leakage circuit), and a third refrigerant leakage control for changing the operation state of a predetermined Refrigerant Circuit (RC) in accordance with the result of the refrigerant leakage circuit determining process.

Description

Thermal load handling system

Technical Field

The present disclosure relates to a thermal load handling system.

Background

Conventionally, as shown in patent document 1 (japanese patent application laid-open No. 2006-38323), there is known a refrigerant system constituting device which constitutes a refrigerant system including a compressor and a heat exchanger connected to a refrigerant pipe through which a refrigerant flows and a heat medium pipe through which a heat medium flows, and which exchanges heat between the refrigerant and the heat medium.

Disclosure of Invention

Technical problem to be solved by the invention

With respect to the refrigerant system constituent devices, there is a possibility that leakage of the refrigerant may occur due to damage to the refrigerant piping, the heat exchanger, or the like, aged deterioration, poor contact, or the like. On the other hand, in a heat load handling system including a plurality of refrigerant systems, it is desirable to be able to quickly determine the refrigerant system that causes refrigerant leakage.

Technical scheme for solving technical problem

A heat load handling system according to a first aspect includes a plurality of refrigerant systems in which a refrigerant circulates, and includes a plurality of refrigerant system components, a casing, a refrigerant leakage detection unit, and a control unit. As a machine constituting one refrigerant system, the refrigerant system constituting machine includes a compressor and/or a heat exchanger. The compressor compresses a refrigerant. The heat exchanger is connected to the refrigerant pipe and the heat medium pipe. The refrigerant pipe is a pipe through which a refrigerant flows. The heat medium pipe is a pipe through which a heat medium flows. The heat exchanger exchanges heat between the refrigerant and the heat medium. The housing houses a plurality of refrigerant system configuration devices together. The refrigerant leakage detection unit detects refrigerant leakage of each refrigerant system individually. The control unit controls the operation of the actuator of each refrigerant system. The control portion executes a first process and a second process in a case where the refrigerant leakage is detected by the refrigerant leakage detecting portion. The first process is a process of determining a refrigerant system in which a refrigerant leak is occurring, i.e., a refrigerant leak system. The second process is a process of changing the operation state of at least one refrigerant system according to the result of the first process.

Thus, in a heat load processing system including a plurality of refrigerant systems, it is possible to quickly identify a refrigerant system in which a refrigerant leak has occurred. Further, the operation state of the predetermined refrigerant system can be changed according to the determination result.

The "refrigerant leakage detection unit" here is a refrigerant leakage sensor that directly detects a leaked refrigerant (leaking refrigerant), a pressure sensor or a temperature sensor that detects a state (pressure or temperature) of the refrigerant in the refrigerant system, and/or a computer that determines whether there is refrigerant leakage from these detection values.

In the heat load processing system according to the second aspect, the control unit controls the refrigerant leakage system to be in the stopped state in the second process. Thus, when refrigerant leakage occurs, further leakage of refrigerant from the refrigerant leakage system is suppressed.

The heat load handling system according to the third aspect of the present invention is the heat load handling system according to the first or second aspect of the present invention, further comprising a refrigerant state sensor. The refrigerant state sensor detects the pressure or temperature of the refrigerant in each refrigerant system. In the first process, the control unit determines a refrigerant leakage system by comparing the states of the refrigerants in the respective refrigerant systems based on the detection values of the refrigerant state sensors. Thus, even when refrigerant leakage occurs in the heat exchanger unit, the leaked refrigerant can be easily discharged from the equipment room to another space.

In the heat load processing system according to the fourth aspect, the control unit determines the refrigerant leakage system in a state where each of the refrigerant systems is operated in the first process, in addition to the heat load processing system according to any one of the first to third aspects.

In the heat load processing system according to a fifth aspect, in addition to the heat load processing system according to any one of the first to third aspects, the control unit specifies the refrigerant leakage system in a state where each of the refrigerant systems is stopped in the first process.

In the heat load processing system according to the sixth aspect, the refrigerant system constituting machine further includes a second heat exchanger. The second heat exchanger condenses or dissipates heat of the refrigerant compressed in the compressor by heat exchange with water. In the first process, the control portion determines the refrigerant leakage system according to the degree of pressure reduction of the high-pressure refrigerant in each refrigerant system. Thus, in the case where the refrigerant system constituting machine includes the second heat exchanger that condenses or radiates heat of the high-pressure refrigerant by heat exchange with water, it is easy to determine the refrigerant leakage system.

In the heat load processing system according to any one of the first to sixth aspects, in the heat load processing system according to the seventh aspect, the control unit controls the refrigerant systems other than the refrigerant leakage system to be in the operating state, among the refrigerant systems that are in the operating state when the refrigerant leakage is detected by the refrigerant leakage detecting unit, in the second process. This allows the refrigerant system in which no refrigerant leakage occurs to continue to operate.

Drawings

Fig. 1 is a schematic configuration diagram of a thermal load processing system.

Fig. 2 is a schematic diagram showing a specific example of the refrigerant used in the refrigerant circuit.

Fig. 3 is a schematic diagram showing an installation mode of the heat load processing system.

Fig. 4 is a schematic plan view of an equipment machine room in which the heat exchanger unit is installed.

Fig. 5 is a perspective view of the heat exchanger package.

Fig. 6 is a schematic view showing an arrangement form of devices in the housing in a plan view.

Fig. 7 is a schematic diagram showing an arrangement form of devices in the housing in a side view.

Fig. 8 is a schematic view showing an arrangement form of devices in the housing in a front view.

Fig. 9 is a schematic view of the base plate as viewed from above.

Fig. 10 is a schematic view of the base plate as viewed from the side.

Fig. 11 is a schematic view schematically showing the arrangement of the exhaust fan unit and the cooling fan of the casing.

Fig. 12 is a block diagram schematically showing a controller and parts connected to the controller.

Fig. 13 is a flowchart showing an example of the processing flow of the controller.

Fig. 14 is a perspective view of a heat exchanger unit according to a first modification.

Fig. 15 is a schematic diagram showing an arrangement form of devices in the heat exchanger unit according to the first modification in a plan view.

Fig. 16 is a schematic view showing an arrangement form of devices in the heat exchanger unit according to the first modification in a front view.

Fig. 17 is a schematic diagram showing an arrangement form of devices in the heat exchanger unit according to the first modification as viewed in side elevation.

Fig. 18 is a schematic view schematically showing a configuration of a heat load processing system according to a first modification.

Detailed Description

Hereinafter, a heat load processing system 100 according to an embodiment of the present disclosure will be described with reference to the drawings. The following embodiments are specific examples, and do not limit the technical scope of the present invention, and can be modified as appropriate without departing from the spirit and scope of the present invention. In the following description, expressions indicating directions such as "up", "down", "left", "right", "front (front)", "rear (back)" and the like are sometimes used. These directions represent the directions indicated by arrows in the drawings, unless otherwise specified. The expressions in these directions are only for the convenience of understanding the embodiments, and do not particularly limit the idea of the present disclosure.

(1) Thermal load handling system 100

Fig. 1 is a schematic configuration diagram of a thermal load processing system 100. The thermal load handling system 100 is a system for handling thermal loads in a set-up environment. In the present embodiment, the heat load processing system 100 is an air conditioning system that performs air conditioning of a target space.

The heat load processing system 100 mainly includes a plurality of (here, four) heat source-side units 10, a heat exchanger unit 30, a plurality of (here, four) utilization-side units 60, a plurality of (here, four) liquid-side communication tubes LP, a plurality of (here, four) gas-side communication tubes GP, a first heat medium communication tube H1 and a second heat medium communication tube H2, a refrigerant leak sensor 70, and a controller 80 that controls the operation of the heat load processing system 100.

In the heat load processing system 100, the heat source-side unit 10 and the heat exchanger unit 30 are connected by the liquid-side communication pipe LP and the gas-side communication pipe GP, and constitute a refrigerant circuit RC in which a refrigerant circulates. In the heat load processing system 100, a plurality of (here, four) refrigerant circuits RC (refrigerant systems) are configured in parallel with the plurality of heat source-side units 10. In other words, in the heat load processing system 100, a plurality of refrigerant circuits RC are formed by the plurality of heat source-side units 10 and the heat exchanger unit 30. The heat load processing system 100 performs a vapor compression refrigeration cycle in each refrigerant circuit RC.

In the present embodiment, the refrigerant sealed in the refrigerant circuit RC is a flammable refrigerant. In addition, flammable refrigerants herein include refrigerants that conform to class 3 (strong flammability), class 2 (weak flammability), subclass 2L (slight flammability) under the ASHRAE34 refrigerant designation and safety classification standard or ISO817 refrigerant designation and safety classification standard in the united states. For example, fig. 2 shows a specific example of the refrigerant used in the present embodiment. In fig. 2, "ASHRAE number" is an ASHRAE number of a refrigerant specified in ISO817, "component" indicates an ASHRAE number of a substance contained in the refrigerant, "mass%" indicates a mass percentage concentration of each substance contained in the refrigerant, and "substitute" indicates a substance name of a refrigerant that is frequently substituted by the refrigerant. In particular, the refrigerant used in the present embodiment is R32. The refrigerant sealed in the refrigerant circuit RC may be a refrigerant not shown in fig. 2, for example, a toxic refrigerant such as CO2 refrigerant or ammonia. The refrigerants sealed in the refrigerant circuits RC do not have to be the same.

In the heat load processing system 100, the heat exchanger unit 30 and the use-side unit 60 are connected by the first heat medium connection tube H1 and the second heat medium connection tube H2, and constitute a heat medium circuit HC in which a heat medium circulates. In other words, in the heat load processing system 100, the heat exchanger unit 30 and the use-side unit 60 constitute the heat medium circuit HC. In the heat medium circuit HC, the heat medium is circulated by a pump 36 (to be described later) that drives the heat exchanger unit 30.

In the present embodiment, the heat medium enclosed in the heat medium circuit HC is a liquid medium such as water or brine (brine), for example. The brine includes, for example, an aqueous sodium chloride solution, an aqueous calcium chloride solution, an aqueous ethylene glycol solution, an aqueous propylene alcohol solution, and the like. The type of the liquid medium is not limited to the one exemplified here, and may be selected as appropriate. In particular, in the present embodiment, brine is used as the heat medium.

(2) Detailed structure

(2-1) Heat Source side Unit 10

In the present embodiment, the heat load processing system 100 includes four heat source side units 10 (see fig. 1). The heat exchanger unit 30 cools and heats the liquid medium by the refrigerant cooled and heated in the four heat source side units 10. However, the number of the heat source side units 10 is an example, and the number is not limited to four. The number of the heat source side units 10 may be one to three, or five or more. In fig. 1, only one of the four heat source-side units 10 is depicted, and the other three are omitted. The heat source-side unit 10, which is not shown, also has the same structure as the structure of the heat source-side unit 10 described below.

The heat source-side unit 10 is a unit that cools or heats a refrigerant using air as a heat source. Each heat source-side unit 10 is connected to the heat exchanger unit 30 through the liquid-side communication pipe LP and the gas-side communication pipe GP. In other words, each heat-source-side unit 10 constitutes a refrigerant circuit RC (refrigerant system) together with the heat exchanger unit 30. That is, in the heat load processing system 100, a plurality of (four in this case) refrigerant circuits RC (refrigerant systems) are configured by connecting a plurality of (four in this case) heat source-side units 10 to the heat exchanger unit 30, respectively. In addition, the refrigerant circuits RC are separated and not communicated.

The place where the heat source-side unit 10 is installed is not limited, and for example, the heat source-side unit is installed on a roof or a space around a building. The heat source-side unit 10 is connected to the heat exchanger unit 30 via the liquid-side communication tube LP and the gas-side communication tube GP, and constitutes a part of the refrigerant circuit RC.

The heat-source-side unit 10 mainly includes a plurality of refrigerant pipes (first pipe P1 to eleventh pipe P11), a compressor 11, an accumulator 12, a four-way selector valve 13, a heat-source-side heat exchanger 14, a subcooler 15, a heat-source-side first control valve 16, a heat-source-side second control valve 17, a liquid-side shutoff valve 18, and a gas-side shutoff valve 19 as the devices constituting the refrigerant circuit RC.

The first pipe P1 connects the gas-side shutoff valve 19 and the first port of the four-way selector valve 13. The second pipe P2 connects the inlet port of the accumulator 12 and the second port of the four-way selector valve 13. The third pipe P3 connects the outlet port of the accumulator 12 and the suction port of the compressor 11. The fourth pipe P4 connects the discharge port of the compressor 11 and the third port of the four-way selector valve 13. The fifth pipe P5 connects the fourth port of the four-way selector valve 13 to the gas-side inlet/outlet of the heat source-side heat exchanger 14. The sixth pipe P6 connects the liquid-side inlet/outlet of the heat source-side heat exchanger 14 and one end of the heat source-side first control valve 16. The seventh pipe P7 connects the other end of the heat source side first control valve 16 and one end of the main flow path 151 of the subcooler 15. The eighth pipe P8 connects the other end of the main flow passage 151 of the subcooler 15 and one end of the liquid side shutoff valve 18.

The ninth pipe P9 connects a portion between both ends of the sixth pipe P6 and one end of the heat source side second control valve 17. The tenth pipe P10 connects the other end of the heat source-side second control valve 17 to one end of the sub-flow passage 152 of the subcooler 15. The eleventh pipe P11 connects the other end of the sub-flow path 152 of the subcooler 15 and the injection port of the compressor 11.

The refrigerant pipes (P1-P11) may be actually constituted by a single pipe, or may be constituted by connecting a plurality of pipes via a joint or the like.

The compressor 11 is a machine that compresses a low-pressure refrigerant in a refrigeration cycle to a high pressure. In the present embodiment, the compressor 11 has an airtight structure in which a positive displacement compression element (not shown) such as a rotary type or a scroll type is driven to rotate by a compressor motor (not shown). The operating frequency of the compressor motor can be controlled by the inverter. That is, the compressor 11 is configured to be controllable in capacity. However, the compressor 11 may be a compressor with a constant capacity.

The accumulator 12 is a container for suppressing excessive suction of the liquid refrigerant into the compressor 11. The accumulator 12 has a predetermined volume according to the amount of refrigerant to be filled into the refrigerant circuit RC.

The four-way switching valve 13 is a flow path switching mechanism for switching the flow of the refrigerant in the refrigerant circuit RC. The four-way selector valve 13 switches between the normal circulation state and the reverse circulation state. When the four-way selector valve 13 is in the positive circulation state, the first port (first pipe P1) and the second port (second pipe P2) communicate with each other, and the third port (fourth pipe P4) and the fourth port (fifth pipe P5) communicate with each other (see the solid line of the four-way selector valve 13 in fig. 1). When the reverse circulation state is achieved, the four-way selector valve 13 causes the first port (first pipe P1) and the third port (fourth pipe P4) to communicate with each other, and causes the second port (second pipe P2) and the fourth port (fifth pipe P5) to communicate with each other (see the broken line of the four-way selector valve 13 in fig. 1).

The heat source side heat exchanger 14 is a heat exchanger that functions as a condenser (or a radiator) or an evaporator of the refrigerant. During the normal cycle operation (operation in which the four-way selector valve 13 is in the normal cycle state), the heat source side heat exchanger 14 functions as a condenser for the refrigerant. In the reverse cycle operation (operation in which the four-way selector valve 13 is in the reverse cycle state), the heat source side heat exchanger 14 functions as an evaporator of the refrigerant. The heat source side heat exchanger 14 includes a plurality of heat transfer tubes and heat transfer fins (not shown). The heat source side heat exchanger 14 is configured to exchange heat between the refrigerant in the heat transfer tubes and air (a heat source side air flow described later) flowing around the heat transfer tubes or the heat transfer fins.

The subcooler 15 is a heat exchanger for setting the refrigerant flowing in to a subcooled liquid refrigerant. The subcooler 15 is, for example, a double-tube heat exchanger, and the subcooler 15 includes a main flow path 151 and a sub-flow path 152. The subcooler 15 is configured to exchange heat between the refrigerant flowing through the main flow passage 151 and the sub-flow passage 152.

The heat source-side first control valve 16 is an electronic expansion valve whose opening degree can be controlled, and reduces the pressure of the refrigerant flowing in or adjusts the flow rate of the refrigerant according to the opening degree. The heat-source-side first control valve 16 can switch between an open state and a closed state. The heat-source-side first control valve 16 is disposed between the heat-source-side heat exchanger 14 and the subcooler 15 (main channel 151).

The heat source-side second control valve 17 is an electronic expansion valve whose opening degree can be controlled, and reduces the pressure of the refrigerant flowing in or adjusts the flow rate of the refrigerant according to the opening degree. The heat-source-side second control valve 17 is capable of switching between an open state and a closed state. The heat-source-side second control valve 17 is disposed between the heat-source-side heat exchanger 14 and the subcooler 15 (sub-channel 152).

The liquid-side shutoff valve 18 is a manual valve disposed at a connection portion between the eighth pipe P8 and the liquid-side communication pipe LP. The liquid-side shutoff valve 18 has one end connected to the eighth pipe P8 and the other end connected to the liquid-side communication pipe LP.

The gas-side shutoff valve 19 is a manual valve disposed at a connection portion between the first pipe P1 and the gas-side communication pipe GP. The gas-side shutoff valve 19 has one end connected to the first pipe P1 and the other end connected to the gas-side communication pipe GP.

The heat-source-side unit 10 also includes a heat-source-side fan 20 that generates a heat-source-side airflow that flows through the heat-source-side heat exchanger 14. The heat-source-side fan 20 is a blower for supplying a heat-source-side airflow, which is a cooling source or a heating source of the refrigerant flowing through the heat-source-side heat exchanger 14, to the heat-source-side heat exchanger 14. The heat-source-side fan 20 includes a heat-source-side fan motor (not shown) as a driving source, and is appropriately controlled in start, stop, and rotation speed according to the situation.

In the heat source side unit 10, a plurality of heat source side sensors S1 (see fig. 12) for detecting the state (mainly, pressure or temperature) of the refrigerant in each refrigerant circuit RC are arranged. The heat source side sensor S1 (refrigerant state sensor) is a temperature sensor such as a pressure sensor, a thermistor, or a thermocouple. The heat source side sensor S1 includes, for example, a first temperature sensor 21 or a second temperature sensor 22, in which the first temperature sensor 21 detects the temperature (suction temperature) of the refrigerant on the suction side (third pipe P3) of the compressor 11, and the second temperature sensor 22 detects the temperature (discharge temperature) of the refrigerant on the discharge side (fourth pipe P4) of the compressor 11. The heat source side sensor S1 includes, for example, a third temperature sensor 23, a fourth temperature sensor 24, or a fifth temperature sensor 25, where the third temperature sensor 23 detects the temperature of the refrigerant on the liquid side (sixth pipe P6) of the heat source side heat exchanger 14, the fourth temperature sensor 24 detects the temperature of the refrigerant in the eighth pipe P8, and the fifth temperature sensor 25 detects the temperature of the refrigerant in the eleventh pipe P11. The heat source side sensor S1 includes, for example, a first pressure sensor 27 and a second pressure sensor 28, the first pressure sensor 27 detecting the pressure (suction pressure) of the refrigerant on the suction side (second pipe P2) of the compressor 11, and the second pressure sensor 28 detecting the pressure (discharge pressure) of the refrigerant on the discharge side (fourth pipe P4) of the compressor 11.

The heat-source-side unit 10 includes a heat-source-side unit controller 29, and the heat-source-side unit controller 29 controls the operation and state of each device included in the heat-source-side unit 10. The heat source-side unit controller 29 includes various circuits, a microcomputer having a microprocessor and a memory chip storing a program to be executed by the microprocessor, and the like to execute the functions thereof. The heat source-side unit controller 29 is electrically connected to the respective devices (11, 13, 16, 17, 20, etc.) included in the heat source-side unit 10 and the heat source-side sensor S1, and inputs and outputs signals to and from each other. The heat-source-side unit controller 29 is electrically connected to a heat exchanger unit controller 49 (described later) of the heat exchanger unit 30 via a communication line, and the like, and transmits and receives control signals to and from each other.

(2-2) Heat exchanger Unit 30

The heat exchanger unit 30 is a device that performs at least one of cooling and heating of the heat medium by exchanging heat between the heat medium and the refrigerant. In the present embodiment, the heat exchanger unit 30 cools and heats the heat medium by exchanging heat between the heat medium and the refrigerant. The heat medium cooled or heated by the liquid refrigerant in the heat exchanger unit 30 is sent to the use-side unit 60.

The heat exchanger unit 30 is a unit that cools or heats the heat medium by exchanging heat between the heat medium sent to the use-side unit 60 and the refrigerant. The installation place of the heat exchanger unit 30 is not limited, and it is installed in a room such as an equipment room. The heat exchanger unit 30 includes, as devices constituting each refrigerant circuit RC, a plurality of (four) refrigerant pipes (refrigerant pipes Pa, Pb, Pc, Pd) having the same number as the number of the heat source side units 10 (the number of the refrigerant circuits RC), an expansion valve 31, and an opening/closing valve 32. The heat exchanger unit 30 includes a heat exchanger 33 as a device constituting each of the refrigerant circuit RC and the heat medium circuit HC.

The refrigerant pipe Pa connects the liquid-side communication pipe LP and one end of the expansion valve 31. The refrigerant pipe Pb connects the other end of the expansion valve 31 and one liquid-side refrigerant inlet/outlet of the heat exchanger 33. The refrigerant pipe Pc connects a gas-side refrigerant inlet/outlet of the heat exchanger 33 and one end of the opening/closing valve 32. The refrigerant pipe Pd connects the other end of the on-off valve 32 and the gas-side communication pipe GP. The refrigerant pipes (Pa to Pd) may be actually constituted by a single pipe, or may be constituted by connecting a plurality of pipes via a joint or the like.

The expansion valve 31 is an electronic expansion valve whose opening degree can be controlled, and reduces the pressure of the refrigerant flowing thereinto or adjusts the flow rate thereof according to the opening degree. The expansion valve 31 can switch between an open state and a closed state. The expansion valve 31 is disposed between the heat exchanger 33 and the liquid-side communication pipe LP.

The opening/closing valve 32 is a control valve that can switch between an open state and a closed state. The opening/closing valve 32 blocks the refrigerant in a closed state. The on-off valve 32 is disposed between the heat exchanger 33 and the gas-side communication pipe GP.

The heat exchanger 33 is formed with a plurality of flow paths (refrigerant flow paths RP) for the refrigerant flowing through the refrigerant circuit RC. In the heat exchanger 33, each refrigerant flow path RP does not communicate with another refrigerant flow path RP. In connection with this, in the heat exchanger 33, the liquid-side inlet and outlet and the gas-side inlet and outlet of the refrigerant flow path RP are formed in the same number as the number of the refrigerant flow paths RP (four in this example). The heat exchanger 33 is formed with a flow path (heat medium flow path HP) for the heat medium flowing through the heat medium circuit HC.

More specifically, the heat exchanger 33 includes a first heat exchanger 34 and a second heat exchanger 35. The first heat exchanger 34 and the second heat exchanger 35 are formed separately. Two separate refrigerant flow paths RP are formed in the first heat exchanger 34 and the second heat exchanger 35, respectively. In the first heat exchanger 34 and the second heat exchanger 35, one end of each refrigerant flow path RP is connected to the refrigerant pipe Pb of the corresponding refrigerant circuit RC, and the other end of each refrigerant flow path RP is connected to the refrigerant pipe Pc of the corresponding refrigerant circuit RC. In the first heat exchanger 34, one end of the heat medium flow path HP is connected to a heat medium pipe Hb described later, and the other end of the heat medium flow path HP is connected to a heat medium pipe Hc described later. In the second heat exchanger 35, one end of the heat medium flow path HP is connected to Hc described later, and the other end of the heat medium flow path HP is connected to a heat medium pipe Hd described later. The heat medium flow paths HP of the first heat exchanger 34 and the second heat exchanger 35 are arranged in series in the heat medium circuit HC. The first heat exchanger 34 and the second heat exchanger 35 are configured to exchange heat between the refrigerant flowing through each refrigerant flow path RP (refrigerant circuit RC) and the heat medium flowing through the heat medium flow path HP (heat medium circuit HC).

The heat exchanger unit 30 further includes a plurality of heat medium pipes (heat medium pipes Ha, Hb, HC, and Hd) and a pump 36 as devices constituting the heat medium circuit HC.

The heat medium pipe Ha has one end connected to the first heat medium communication pipe H1 and the other end connected to the suction-side port of the pump 36. One end of the heat medium pipe Hb is connected to the discharge port of the pump 36, and the other end is connected to one end of the heat medium flow path HP of the first heat exchanger 34. One end of the heat medium pipe Hc is connected to the other end of the heat medium flow path HP of the first heat exchanger 34, and the other end of the heat medium pipe Hc is connected to one end of the heat medium flow path HP of the second heat exchanger 35. One end of the heat medium pipe Hd is connected to the other end of the heat medium flow path HP of the second heat exchanger 35, and the other end of the heat medium pipe Hd is connected to the second heat medium communication tube H2. The heat medium pipes (Ha-Hd) may be actually formed of a single pipe, or may be formed by connecting a plurality of pipes via a joint or the like.

The pump 36 is disposed in the heat medium circuit HC. The pump 36 sucks the heat medium and discharges it during operation. The pump 36 includes a drive source, i.e., a motor, and the rotational speed is adjusted by performing variable frequency control on the motor. That is, the discharge flow rate of the pump 36 is variable. The heat exchanger unit 30 may have a plurality of pumps 36 connected in series or in parallel in the heat medium circuit HC. Further, the pump 36 may be a fixed displacement pump.

Further, the heat exchanger unit 30 is provided with a plurality of heat exchanger unit sensors S2 (see fig. 12) for detecting the state (mainly pressure or temperature) of the refrigerant in each refrigerant circuit RC. The heat exchanger unit sensor S2 (refrigerant condition sensor) is a temperature sensor such as a pressure sensor, a thermistor, or a thermocouple. The heat exchanger unit sensor S2 includes, for example, a sixth temperature sensor 41 and a seventh temperature sensor 42, the sixth temperature sensor 41 detecting the temperature of the refrigerant on the liquid side (refrigerant pipe Pb) of the heat exchanger 33 (refrigerant flow path RP), and the seventh temperature sensor 42 detecting the temperature of the refrigerant on the gas side (refrigerant pipe Pc) of the heat exchanger 33 (refrigerant flow path RP). The heat exchanger unit sensor S2 includes, for example, a third pressure sensor 43 and a fourth pressure sensor 44, the third pressure sensor 43 detecting the pressure of the refrigerant on the liquid side (refrigerant pipe Pb) of the heat exchanger 33 (refrigerant flow path RP), and the fourth pressure sensor 44 detecting the pressure of the refrigerant on the gas side (refrigerant pipe Pc) of the heat exchanger 33 (refrigerant flow path RP).

The heat exchanger unit 30 further includes an exhaust fan unit 45, and the exhaust fan unit 45 is configured to discharge the leaked refrigerant from the heat exchanger unit 30 (refrigerant circuit RC) when the refrigerant leaks from the heat exchanger unit 30. The exhaust fan unit 45 includes an exhaust fan 46. The exhaust fan 46 is driven in conjunction with a drive source (e.g., a fan motor). The exhaust fan 46 generates a first air flow AF1 that flows out from the inside of the heat exchanger unit 30 to the outside (here, an equipment room R described later) when driven. The type of the exhaust fan 46 is not particularly limited, and examples thereof include a sirocco fan and a propeller fan. Further, the exhaust fan unit 45 includes a flow path forming member 47 (see fig. 11) that forms a flow path of the first air flow AF 1. The flow path forming member 47 is not particularly limited as long as it is a member that forms an air flow path of the first air flow AF1, and is, for example, a pipe, a hose, or the like. The flow passage forming member 47 is formed with an intake port 47a (see fig. 10 and 11) of the first air flow AF 1.

The heat exchanger assembly 30 also has a cooling fan 48. The cooling fan 48 is driven in conjunction with a drive source (e.g., a fan motor). The cooling fan 48 generates a second air flow AF2 when driven, and the second air flow AF2 is used to cool electrical components (heat generating components) arranged in the heat exchanger unit 30. The cooling fan 48 is disposed so that the second air flow AF2 flows around the heat generating components, exchanges heat, and then flows out from the inside of the heat exchanger unit 30 to the outside (here, an equipment room R described later). The type of the cooling fan 48 is not particularly limited, and examples thereof include a sirocco fan and a propeller fan.

The heat exchanger unit 30 further includes a heat exchanger unit controller 49, and the heat exchanger unit controller 49 controls the operation and state of each device included in the heat exchanger unit 30. The heat exchanger unit control unit 49 includes a microcomputer having a microprocessor and a memory chip storing a program to be executed by the microprocessor, various electric components, and the like in order to execute the functions thereof. The heat exchanger unit controller 49 is electrically connected to each device (31, 32, 36, 46, 48, etc.) included in the heat exchanger unit 30 and the heat exchanger unit sensor S2, and inputs and outputs signals to and from each other. The heat exchanger unit controller 49 is electrically connected to the heat source-side unit controller 29, a controller (not shown) disposed in the use-side unit 60, a remote controller (not shown), and the like via a communication line, and transmits and receives control signals to and from each other. The electric components included in the heat exchanger unit control portion 49 are cooled by the second air flow AF2 generated by the cooling fan 48.

(2-3) utilizing side machine group 60

The utilization-side unit 60 is a device that utilizes the heat medium cooled/heated in the heat exchanger unit 30. Each of the usage-side units 60 is connected to the heat exchanger unit 30 via the first heat medium communication tube H1, the second heat medium communication tube H2, and the like. The utilization-side unit 60 and the heat exchanger unit 30 together constitute a heat medium circuit HC.

In the present embodiment, the utilization-side unit 60 is, for example, an air handling unit or a fan coil unit that performs air conditioning by exchanging heat between the heat medium cooled and heated in the heat exchanger unit 30 and air.

Only one utilization-side unit 60 is illustrated in fig. 1. However, the heat load processing system 100 may include a plurality of usage-side units, and the heat medium cooled/heated in the heat exchanger unit 30 may be branched and sent to the plurality of usage-side units. When the heat load processing system 100 includes a plurality of usage-side units, the plurality of usage-side units may be all of the same type, or the plurality of usage-side units may include a plurality of types of devices.

(2-4) liquid-side communicating tube LP and gas-side communicating tube GP

The liquid-side communication tubes LP and the gas-side communication tubes GP connect the heat exchanger unit 30 and the corresponding heat source-side unit 10 to form a refrigerant flow path. The liquid-side communication pipe LP and the gas-side communication pipe GP are installed at the installation site. The liquid-side communication pipe LP or the gas-side communication pipe GP may be actually constituted by a single pipe, or may be constituted by connecting a plurality of pipes via a joint or the like.

(2-5) the first heat medium communication tube H1 and the second heat medium communication tube H2

The first heat medium communication tube H1 and the second heat medium communication tube H2 are connected between the heat exchanger unit 30 and the corresponding use-side unit 60, and constitute a flow path of the heat medium. The first heat medium communication tube H1 and the second heat medium communication tube H2 are installed at the installation site. The first heat medium communication tube H1 or the second heat medium communication tube H2 may be formed of a single pipe or may be formed by connecting a plurality of pipes via a joint or the like.

(2-6) refrigerant leak sensor 70

The refrigerant leakage sensor 70 is a sensor for detecting refrigerant leakage in a space (herein, an equipment room R described later) in which the heat exchanger unit 30 is disposed. More specifically, the refrigerant leakage sensor 70 detects leaked refrigerant in the heat exchanger unit 30. In the present embodiment, a known general-purpose product is used as the refrigerant leakage sensor 70 depending on the type of refrigerant sealed in the refrigerant circuit RC. The refrigerant leakage sensor 70 is disposed in a space where the heat exchanger unit 30 is disposed. In the present embodiment, the refrigerant leakage sensor 70 is disposed in the heat exchanger unit 30.

The refrigerant leakage sensor 70 continuously or intermittently outputs an electric signal (refrigerant leakage sensor detection signal) corresponding to the detection value to the controller 80. More specifically, the refrigerant leakage sensor detection signal output from the refrigerant leakage sensor 70 changes in voltage in accordance with the concentration of the refrigerant detected by the refrigerant leakage sensor 70. In other words, the refrigerant leakage sensor detection signal is output to the controller 80 in a form capable of determining the presence or absence of refrigerant leakage in the refrigerant circuit RC and also determining the concentration of the leaked refrigerant in the space in which the refrigerant leakage sensor 70 is provided (more specifically, the concentration of the refrigerant detected by the refrigerant leakage sensor 70). That is, the refrigerant leakage sensor 70 corresponds to a "refrigerant leakage detecting unit" that detects a leaked refrigerant in the heat exchanger unit 30 (equipment room R) by directly detecting the refrigerant (more specifically, the concentration of the refrigerant) flowing out of the refrigerant circuit RC.

(2-7) controller 80

The controller 80 is a computer that controls the operation of the heat load processing system 100 by controlling the state of each device. In the present embodiment, the controller 80 is configured to be connected to the heat-source-side unit controller 29, the heat exchanger unit controller 49, and devices connected thereto (for example, a controller and a remote controller disposed in the usage-side unit) via communication lines. That is, in the present embodiment, the controller 80 is realized by causing the heat-source-side unit controller 29, the heat-exchanger-unit controller 49, and the devices connected thereto to cooperate with each other. Details regarding the controller 80 will be described later.

(3) Flow of refrigerant and heat medium during operation

Next, the flow of the refrigerant in the refrigerant circuit RC and the flow of the heat medium in the heat medium circuit HC will be described. The heat load processing system 100 mainly performs a forward cycle operation and a reverse cycle operation. The positive cycle operation is an operation in which the heat medium circulating in the heat medium circuit HC is cooled by the refrigerant circulating in the refrigerant circuit RC, and the object to be cooled (heat load) is cooled by the cooled heat medium. The reverse circulation operation is an operation in which the heat medium circulating in the heat medium circuit HC is heated by the refrigerant circulating in the refrigerant circuit RC, and the heating target (heat load) is heated by the heated heat medium. In each operation, the heat source side unit 10 to be operated is appropriately selected in accordance with the heat load. In each operation, the rotation speeds of the compressor 11 and the heat-source-side fan 20 of the heat-source-side unit 10 and the pump 36 of the heat exchanger unit 30 during the operation are appropriately adjusted.

(3-1) flow during Positive circulation operation

In the positive cycle operation, the four-way selector valve 13 is controlled to a positive cycle state. When the positive cycle operation is started, the refrigerant is sucked into the compressor 11, compressed, and discharged in the heat source side unit 10 (refrigerant circuit RC) during the operation. The gas refrigerant discharged from the compressor 11 flows into the heat source side heat exchanger 14.

The gas refrigerant flowing into the heat source-side heat exchanger 14 is condensed (or radiated) in the heat source-side heat exchanger 14 by heat exchange with the heat source-side air flow sent by the heat source-side fan 20. The refrigerant flowing out of the heat source side heat exchanger 14 branches while flowing through the sixth pipe P6.

While flowing through the sixth pipe P6, one of the branched refrigerants flows into the heat source side first control valve 16, is depressurized or has a flow rate adjusted according to the opening degree of the heat source side first control valve 16, and then flows into the main flow path 151 of the subcooler 15. The refrigerant flowing into the main flow path 151 of the subcooler 15 exchanges heat with the refrigerant flowing through the sub-flow path 152, is further cooled, and becomes a subcooled liquid refrigerant. The liquid refrigerant flowing out of the main flow passage 151 of the subcooler 15 flows out of the heat source-side unit 10 and flows into the heat exchanger unit 30 via the liquid-side communication tube LP.

The other refrigerant branched while flowing through the sixth pipe P6 flows into the heat source side second control valve 17, is depressurized or adjusted in flow rate according to the opening degree of the heat source side second control valve 17, and then flows into the sub-flow passage 152 of the subcooler 15. The refrigerant flowing into the sub-flow passage 152 of the subcooler 15 exchanges heat with the refrigerant flowing through the main flow passage 151, and is then injected into the compressor 11 through the eleventh pipe P11.

The refrigerant flowing into the heat exchanger unit 30 flows into the expansion valve 31 via the corresponding refrigerant pipe Pa, is reduced in pressure to a low pressure in the refrigeration cycle according to the opening degree of the expansion valve 31, and then flows into the corresponding refrigerant flow passage RP of the heat exchanger 33. The refrigerant flowing into the refrigerant passage RP of the heat exchanger 33 is evaporated by heat exchange with the heat medium flowing through the heat medium passage HP, and flows out of the heat exchanger 33. The refrigerant flowing out of the heat exchanger 33 flows out of the heat exchanger unit 30 through the refrigerant pipes Pc and Pd.

The refrigerant flowing out of the heat exchanger unit 30 flows into the heat source-side unit 10 via the gas-side communication tube GP. The refrigerant flowing into the heat source side unit 10 flows into the accumulator 12 through the first pipe P1, the second pipe P2, and the like. The refrigerant flowing into the accumulator 12 is once accumulated and then sucked into the compressor 11 again.

In the heat medium circuit HC, the pump 36 sends the heat medium from the first heat medium communication tube H1 to the heat medium flow path HP of the heat exchanger 33. The heat medium sent to the heat medium flow path HP is cooled by heat exchange with the refrigerant flowing through the refrigerant flow path RP, and flows out of the heat exchanger 33. The heat medium flowing out of the heat exchanger 33 flows out of the heat exchanger unit 30 through the heat medium pipe Hd and the like.

The heat medium flowing out of the heat exchanger unit 30 is sent to the operating use-side unit 60 via the second heat medium communication tube H2 or the like. The heat medium sent to the use-side unit 60 is heated by heat exchange with a predetermined object to be cooled (here, air of a living space SP described later), and flows out from the use-side unit 60. The heat medium flowing out of the use-side unit 60 flows into the heat exchanger unit 30 again via the first heat medium communication tube H1 and the like.

(3-2) flow in reverse circulation operation

In the reverse circulation operation, the four-way selector valve 13 is controlled to a reverse circulation state. When the reverse cycle operation is started, the refrigerant is sucked into the compressor 11, compressed, and discharged in the heat source side unit 10 (refrigerant circuit RC) during the operation. The gas refrigerant discharged from the compressor 11 flows out of the heat source unit 10 through the fourth pipe P4, the first pipe P1, and the like.

The refrigerant flowing out of the heat source unit 10 flows into the heat exchanger unit 30 via the gas-side communication tube GP. The refrigerant flowing into the heat exchanger unit 30 flows into the corresponding refrigerant flow paths RP of the heat exchanger 33 through the corresponding refrigerant pipes Pd, Pc, and the like. The refrigerant flowing into the refrigerant passage RP of the heat exchanger 33 condenses (or radiates heat) by exchanging heat with the heat medium flowing through the heat medium passage HP, and flows out of the heat exchanger 33.

The refrigerant flowing out of the heat exchanger 33 flows into the expansion valve 31 through the refrigerant pipe Pb and the like, is reduced in pressure to a low pressure in the refrigeration cycle according to the opening degree of the expansion valve 31, and then flows out of the heat exchanger unit 30 through the refrigerant pipe Pa and the like.

The refrigerant flowing out of the heat exchanger unit 30 flows into the heat-source unit 10 via the liquid-side communication tube LP and the like. The refrigerant flowing into the heat source-side unit 10 flows through the seventh pipe P7, the sixth pipe P6, and the like, and flows into the heat source-side heat exchanger 14. The refrigerant flowing into the heat source side heat exchanger 14 exchanges heat with the heat source side air flow sent by the heat source side fan 20 in the heat source side heat exchanger 14, evaporates, and flows out of the heat source side heat exchanger 14.

The refrigerant flowing out of the heat source side heat exchanger 14 flows into the accumulator 12 through the fifth pipe P5, the second pipe P2, and the like. The refrigerant flowing into the accumulator 12 is once accumulated and then sucked into the compressor 11 again.

In the heat medium circuit HC, the pump 36 sends the heat medium from the first heat medium communication tube H1 to the heat medium flow path HP of the heat exchanger 33. The heat medium sent to the heat medium flow path HP is heated by heat exchange with the refrigerant flowing through the refrigerant flow path RP, and flows out of the heat exchanger 33. The heat medium flowing out of the heat exchanger 33 flows out of the heat exchanger unit 30 through the heat medium pipe Hd and the like.

The heat medium flowing out of the heat exchanger unit 30 is sent to the operating use-side unit 60 via the second heat medium communication tube H2 or the like. The heat medium sent to the use-side unit 60 is cooled by heat exchange with a heated object (here, air in the living space SP described later), and flows out of the use-side unit 60. The heat medium flowing out of the use-side unit 60 flows into the heat exchanger unit 30 again via the first heat medium communication tube H1 and the like.

(4) Installation mode of heat load processing system 100

Fig. 3 is a schematic diagram showing an installation mode of the heat load processing system 100. The installation location of the heat load processing system 100 is not particularly limited, and may be installed in a building, a commercial facility, a factory, or the like. In the present embodiment, the heat load processing system 100 is installed in a building B1 in the form shown in fig. 3. Building B1 has multiple floors. The number of floors and the number of rooms in the building B1 can be changed as appropriate.

The building B1 is provided with an equipment machine room R. The equipment room R is a space in which electric equipment such as a distribution board and a generator, and cooling and heating equipment such as a boiler are disposed. The facility machine room R is a space where a person can enter and exit and stay. For example, the equipment machine room R is a space where a person can walk, such as a basement. In the present embodiment, the equipment machine room R is located on the lowermost floor of the building B1. The building B1 is provided with a living space SP in which people move. The building B1 is provided with a plurality of living spaces SP. In the present embodiment, the living space SP is located at the upper floor of the floor where the equipment machine room R is installed.

In fig. 3, the heat source side unit 10 is installed on the roof of a building B1. Further, the heat exchanger unit 30 is provided in the equipment machine room R. In connection with this, the liquid-side communication pipe LP and the gas-side communication pipe GP extend in the vertical direction between the roof and the equipment room R. More specifically, as shown in fig. 4, the heat exchanger unit 30 is installed in the equipment room R together with other devices (devices OD1 to OD 3). The devices OD1 to OD3 are not particularly limited, and examples thereof include a boiler, a generator, and a switchboard. In addition, only the heat exchanger unit 30 may be provided in the equipment room R.

In fig. 3, each of the usage-side units 60 is disposed in the corresponding living space SP. In association with this, the first heat medium communication tube H1 and the second heat medium communication tube H2 extend in the vertical direction between the living space SP and the equipment room R.

The building B1 is provided with a ventilation device 200 that performs ventilation (forced ventilation or natural ventilation) of the equipment room R. Each ventilator 200 is provided in the equipment room R. Specifically, the equipment room R is provided with a ventilation fan 210 as the ventilation device 200. The ventilation fan 210 is connected to the plurality of ventilation ducts D. When driven, the ventilation fan 210 discharges air (inside air RA) in the equipment room R to the outside space as exhaust air EA, and supplies air (outside air OA) in the outside space to the equipment room R as supply air SA, thereby ventilating the equipment room R. That is, the ventilation fan 210 corresponds to a "ventilation device" that ventilates the equipment room R. The ventilation fan 210 is electrically connected to the controller 80 via an adapter 80a (see fig. 12). The controller 80 can control the operation (start, stop, rotation speed, etc.) of the ventilation fan 210. As for the control of the ventilation fan 210, an intermittent operation mode in which the ventilation fan 210 is intermittently operated and a continuous operation mode in which the ventilation fan 210 is continuously operated are appropriately switched.

Further, an opening/closing mechanism 220 is provided as the ventilator 200 in the equipment room R. The opening/closing mechanism 220 is a mechanism capable of switching between an open state in which the equipment room R communicates with another space (for example, an external space) and a closed state in which the equipment room R is blocked from the other space (for example, the external space). That is, the opening/closing mechanism 220 opens and closes an opening that communicates the equipment room R with the other space. The opening/closing mechanism 220 is, for example, a door, a lifting/lowering port, a window, a grill, or the like, which can be controlled to open and close. The opening/closing mechanism 220 is electrically connected to the controller 80 via an adapter 80b (see fig. 12). The state (on state or off state) of the ventilation fan 210 can be controlled by the controller 80.

(5) Configuration of the heat exchanger unit 30

Fig. 5 is a perspective view of the heat exchanger unit 30. The heat exchanger unit 30 has a casing 50 for housing each device. Fig. 6 is a schematic diagram showing an arrangement form of devices in the housing 50 in a plan view. Fig. 7 is a schematic diagram showing an arrangement form of devices in the housing 50 in a side view. Fig. 8 is a schematic diagram showing an arrangement form of devices in the housing 50 in a front view.

In the present embodiment, the casing 50 houses a plurality of units (hereinafter referred to as "machine units R1") constituting one refrigerant circuit RC (refrigerant system), the number of which is the same as the number of refrigerant circuits RC (four in this case). That is, a plurality of machine units R1 (refrigerant system-constituting machines) constituting different refrigerant systems are collectively housed in the casing 50. In the present embodiment, as shown in fig. 6 to 8, the equipment unit R1 including the refrigerant flow path RP of the first heat exchanger 34 or the second heat exchanger 35, the expansion valve 31, the opening/closing valve 32, and the refrigerant pipes Pa to Pd is housed in the casing 50 together with the other equipment units R1. Further, the casing 50 accommodates devices constituting the heat medium circuit HC.

The housing 50 has an approximately rectangular parallelepiped shape. The housing 50 is provided by mounting legs or stands or the like. The case 50 is formed with a lower space Sa and an upper space Sb therein. In addition, the lower space Sa and the upper space Sb are not completely separated and partially communicate.

In the lower space Sa, the expansion valves 31, the opening/closing valves 32, the heat exchanger 33, the pump 36, the refrigerant pipes Pa to Pd, the heat medium pipes Ha to Hd, and the heat exchanger unit sensor S2 are disposed. In the present embodiment, as shown in fig. 6, the first heat exchanger 34, the second heat exchanger 35, and the pump 36 are arranged in the lower space Sa from right to left. In front of the heat exchanger 33, the expansion valves 31, the opening/closing valves 32, and the refrigerant pipes Pa to Pd are arranged in line in correspondence with the positions of the refrigerant passages RP to be communicated. The heat medium pipe Ha is disposed behind the pump 36. The heat medium pipe Hb extends from the front of the pump 36 to the rear of the second heat exchanger 35. The heat medium pipes Hc to Hd are disposed behind the heat exchanger 33.

The portion indicated by reference numeral "a 1" in fig. 7 and 8 indicates the highest height portion (hereinafter referred to as "uppermost portion a 1") included in each of the refrigerant pipes Pa to Pd arranged in the heat exchanger unit 30. The uppermost portion a1 is located at a height corresponding to a distance h1 in the vertical direction from the bottom portion of the housing 50.

The portion indicated by reference numeral "a 2" in fig. 7 and 8 indicates the portion having the lowest height of each of the refrigerant pipes Pa to Pd in the heat exchanger unit 30 (hereinafter referred to as "lowermost portion a 2"). The lowermost portion a2 is located at a height corresponding to a distance h2 in the vertical direction from the bottom portion of the housing 50. The lowermost portion a2 is located at a height corresponding to a distance h2 in the vertical direction from the bottom portion of the housing 50.

The upper space Sb is a space located above the lower space Sa. The electrical component box 55 for housing the heat exchanger unit controller 49 is disposed in the upper space Sb.

The housing 50 has a bottom plate 58 as shown in fig. 9 and 10. Fig. 9 is a schematic view of the bottom plate 58 as viewed from above. Fig. 10 is a schematic view of the bottom plate 58 as viewed from the side.

The bottom plate 58 is a member constituting a bottom portion of the housing 50. Further, the bottom plate 58 is one of the members forming the lower space Sa. The bottom plate 58 is disposed below the heat exchanger 33. The bottom plate 58 also functions as a water collecting tray that receives dew condensation water dripping from the heat exchanger 33. The bottom plate 58 has a bottom portion 581 having a substantially rectangular shape in plan view. Further, the bottom plate 58 is formed with a discharge port 58a, and the discharge port 58a is used for discharging water received by the bottom plate portion 581. The discharge port 58a is disposed near the center of one side of the bottom plate 581 in a plan view (see fig. 9). The bottom portion 581 is inclined so as to form a descending slope toward the discharge port 58 a. In association with this, the bottom plate 58 is configured such that the depth increases toward the discharge port 58 a. In other words, a space (a space immediately above the bottom plate Si) deeper in the direction of the discharge port 58a is formed above the bottom plate portion 581 of the bottom plate 58.

The refrigerant leak sensor 70 is disposed on the bottom portion 581 of the bottom plate 58. That is, the refrigerant leak sensor 70 is disposed in the space Si directly above the bottom plate. More specifically, the refrigerant leakage sensor 70 is disposed in the vicinity of the discharge port 58 a. That is, the refrigerant leak sensor 70 is disposed at a position where the depth of the space Si immediately above the bottom plate is increased.

Fig. 11 is a schematic diagram schematically showing the arrangement of the exhaust fan unit 45 and the cooling fan 48 of the casing 50. The casing 50 is formed with an exhaust port 50a, and the exhaust port 50a is used to exhaust the first air flow AF1 generated by the exhaust fan 46. The discharge port 50a discharges the first air flow AF1 from the inside of the heat exchanger unit 30 to the outside. The discharge port 50a is located near the upper end of the lower space Sa. More specifically, the discharge port 50a is disposed at a position higher than the height h 1. That is, the discharge port 50a is formed at a position higher than the uppermost portion a1 (the uppermost portion of the refrigerant pipe housed in the heat exchanger unit 30). The discharge port 50a communicates with the secondary side (outlet side) of the exhaust fan 46.

Further, an exhaust fan unit 45 is disposed in the lower space Sa of the casing 50. The exhaust fan unit 45 is disposed in the lower space Sa in such a manner as to introduce the first air flow AF1 from the space Si directly above the floor and discharge it from the discharge port 50 a. More specifically, flow path forming member 47 of exhaust fan unit 45 is disposed so as to extend in the vertical direction from space Si immediately above the bottom plate.

One end of the flow path forming member 47 is open and functions as a suction port (hereinafter, referred to as "suction port 47 a") for sucking the first air flow AF 1. The suction port 47a is disposed at a position lower than the height h1 (see fig. 11). That is, the suction port 47a of the first air flow AF1 is formed at a position lower than the uppermost portion a1 (the highest portion of the refrigerant pipes housed in the heat exchanger unit 30). The suction port 47a is disposed at a position lower than the lowermost portion a2 (the lowermost portion of the refrigerant pipe stored in the heat exchanger unit 30). More specifically, the suction port 47a is disposed in the space Si immediately above the floor (see fig. 10). That is, the suction port 47a may be formed in a space in the bottom plate 58 (water collection tray). In another aspect, the suction port 47a may be disposed on the bottom plate 58.

The other end of the flow path forming member 47 is open and communicates with the primary side (suction side) of the exhaust fan 46. The other end of the flow path forming member 47 is located at a position higher than the height h 1. That is, the other end of the flow passage forming member 47 is formed at a position higher than the uppermost portion a1 (the uppermost portion of the refrigerant pipe housed in the heat exchanger unit 30).

The exhaust fan 46 is disposed in the vicinity of the discharge port 50 a. The exhaust fan 46 is located at a position higher than the height h 1. That is, the exhaust fan 46 is disposed at a position higher than the uppermost portion a1 (the uppermost portion of the refrigerant pipe housed in the heat exchanger unit 30). The exhaust fan 46 is disposed in the lower space Sa in the vicinity of the heat medium pipes Ha to Hd. Thus, when refrigerant leakage occurs in the heat exchanger unit 30, the leaked refrigerant is prevented from flowing to the living space SP side through the heat medium pipes Ha to Hd.

Further, a cooling fan 48 is disposed in the upper space Sb of the casing 50. The cooling fan 48 is disposed in the upper space Sb so as to flow the second air flow AF2 around the heat generating components included in the heat exchanger unit controller 49 and flow out to the outside (here, the equipment room R). The cooling fan 48 is disposed in the vicinity of the heat exchanger unit control unit 49 housed in the electrical component box 55. In the present embodiment, the cooling fan 48 is disposed at a position higher than the height h 1. That is, the cooling fan 48 is disposed at a position higher than the exhaust fan 46.

(6) Details of the controller 80

In the heat load processing system 100, the heat-source-side unit controller 29 and the heat-exchanger unit controller 49 are connected by a communication line to constitute a controller 80. Fig. 12 is a block diagram schematically showing the controller 80 and parts connected to the controller 80.

The controller 80 has a plurality of control modes, and controls the operation of each machine according to the changed control mode. In the present embodiment, the controller 80 has, as control modes, a normal operation mode that transitions during operation (when no refrigerant leakage occurs) and a refrigerant leakage mode that transitions when refrigerant leakage occurs (more specifically, when a leaked refrigerant is detected).

The controller 80 is electrically connected to the devices included in the heat load processing system 100, for example, the compressor 11, the four-way selector valve 13, the heat-source-side first control valve 16, the heat-source-side second control valve 17, the heat-source-side fan 20, and the heat-source-side sensor S1 included in the heat-source-side unit 10, the devices included in the heat-exchanger unit 30 (specifically, the expansion valves 31, the opening/closing valves 32, the pump 36, the exhaust fan 46, the cooling fan 48, and the heat-exchanger-unit sensor S2), and the refrigerant leakage sensor 70, and the like. The controller 80 is electrically connected to the ventilator 200 disposed in the equipment room R. More specifically, the controller 80 is electrically connected to the ventilation fan 210 via an adapter 80a, and is electrically connected to the opening/closing mechanism 220 via an adapter 80 b. The controller 80 is electrically connected to an output device 300 (for example, a display capable of outputting display information, a speaker capable of outputting audio information, and the like) capable of outputting predetermined information.

The controller 80 mainly includes a storage unit 81, an input control unit 82, a mode control unit 83, a refrigerant leakage determination unit 84, an apparatus control unit 85, a drive signal output unit 86, and an information output control unit 87. The functional units in the controller 80 are realized by cooperating CPU, memory, and various electric and electronic components included in the heat-source-side unit controller 29 and/or the heat-exchanger-unit controller 49.

(6-1) storage section 81

The storage section 81 is configured by, for example, a ROM, a RAM, a flash memory, and the like, and includes a volatile storage area and a nonvolatile storage area. The storage unit 81 includes a program storage area M1 for storing a control program defining processing of each unit of the controller 80, the program storage area M1.

The storage unit 81 includes a detection value storage area M2 for storing detection values of various sensors. The detection value storage area M2 stores, for example, detection values (suction pressure, discharge pressure, suction temperature, discharge temperature, temperature and pressure of the refrigerant flowing into the heat exchanger 33, temperature and pressure of the refrigerant flowing out of the heat exchanger 33, and the like) of each heat source side sensor S1 and each heat exchanger unit sensor S2.

The storage unit 81 includes a sensor signal storage region M3 for storing a refrigerant leakage sensor detection signal (a detection value of the refrigerant leakage sensor 70) transmitted from the refrigerant leakage sensor 70 in the sensor signal storage region M3. The refrigerant leakage signal stored in the sensor signal storage area M3 is updated every time the refrigerant leakage signal output from the refrigerant leakage sensor 70 is received.

The storage unit 81 includes a command storage area M4 for storing a command input by a user through an input device (not shown).

Further, the storage section 81 is provided with a plurality of flags having a predetermined number of bits. For example, the storage unit 81 is provided with a control mode discrimination flag M5 that can discriminate the control mode shifted by the controller 80 with respect to the control mode discrimination flag M5. The control mode discerning flag M5 includes the number of bits corresponding to the number of control modes, and establishes bits corresponding to the control modes to be transitioned.

Further, the storage unit 81 is provided with a refrigerant leakage detection flag M6 for discriminating that a refrigerant leakage is detected in the heat exchanger unit 30, the refrigerant leakage detection flag M6 being set. More specifically, the refrigerant leakage detection flag M6 has the number of bits corresponding to the number of refrigerant circuits RC (machine units R1), and is able to establish a bit corresponding to a refrigerant circuit RC (refrigerant leakage circuit) in which a refrigerant leakage is supposed to occur. That is, the refrigerant leakage detection flag M6 is configured to be able to distinguish which refrigerant circuit RC has a refrigerant leakage when a refrigerant leakage occurs in any refrigerant circuit RC. The refrigerant leakage detection flag M6 is switched by the refrigeration leakage determination unit 84.

(6-2) input control section 82

The input control unit 82 is a functional unit that functions as an interface for receiving signals output from the respective devices connected to the controller 80. For example, the input controller 82 receives signals output from the sensors (S1, S2), the remote controller, and the like, and stores the signals in the corresponding storage areas of the storage 81 or sets a predetermined flag.

(6-3) mode control section 83

The mode control unit 83 is a functional unit for switching control modes. In a normal state (when the refrigerant leakage determination flag M6 is not set), the mode control unit 83 switches the control mode to the normal operation mode. When the refrigerant leakage determination flag M6 is set, the mode control portion 83 switches the control mode to the refrigerant leakage mode. The mode control portion 83 establishes the control mode discrimination flag M5 according to the shifted control mode.

(6-4) refrigerant leak determination section 84

The refrigerant leakage determination unit 84 is a functional unit that determines whether or not refrigerant leakage occurs in the refrigerant circuit RC and identifies a refrigerant leakage circuit (refrigerant leakage system). Specifically, when a predetermined refrigerant leakage detection condition is satisfied, the refrigerant leakage determination unit 84 determines that refrigerant leakage is occurring in the refrigerant circuit RC, and establishes the refrigerant leakage detection flag M6.

In the present embodiment, it is determined whether the refrigerant leakage detection condition is satisfied or not based on the refrigerant leakage sensor detection signal in the sensor signal storage area M3. Specifically, the refrigerant leakage detection condition is satisfied when the time during which the voltage value of any of the refrigerant leakage sensor detection signals (the detection value of the refrigerant leakage sensor 70) is equal to or greater than a predetermined first reference value continues for a predetermined time period t1 or longer. The first reference value is a value (concentration of the refrigerant) in the case where the refrigerant in the refrigerant circuit RC is assumed to leak. The predetermined time t1 is set to a time at which it can be determined that the refrigerant leakage sensor detection signal is not an instantaneous signal. The predetermined time t1 is appropriately set according to the type of refrigerant sealed in the refrigerant circuit RC, the specifications of each device, the installation environment, and the like, and is defined in the control program. The refrigerant leakage determination unit 84 is configured to be able to measure a predetermined time t 1. The first reference value is appropriately set in accordance with the type of refrigerant sealed in the refrigerant circuit RC, design specifications, installation environment, and the like, and is defined in the control program.

The refrigerant leakage determination unit 84 executes the refrigerant leakage circuit determination process when the refrigerant leakage detection condition is satisfied. The refrigerant leakage circuit determination process is a process for determining a refrigerant leakage circuit (i.e., a process of discriminating in which refrigerant circuit RC a refrigerant leakage has occurred).

In the refrigerant leak circuit determination process, the refrigerant leak determination unit 84 determines the refrigerant leak circuit (the refrigerant circuit RC in which the refrigerant leak occurs) based on any/all of the detection values of the heat source side sensors S1 and the heat exchanger unit sensors S2. Specifically, the refrigerant leakage determination unit 84 requests the equipment control unit 85 to control each refrigerant circuit RC (equipment unit R1) to be in an operating state. After that, the refrigerant circuit RC in which no refrigerant leakage occurs is started and the state is stabilized is waited for the elapse of a predetermined time (time required for the refrigerant circuit RC to be stabilized), and the values of the heat source side sensor S1 and the heat exchanger unit sensor S2 of the refrigerant circuits RC are compared to determine the refrigerant leakage circuit. That is, the refrigerant leakage determination unit 84 determines the refrigerant leakage circuit based on the level of any/all of the detection value of the first pressure sensor 27 (suction pressure), the detection value of the second pressure sensor 28 (discharge pressure), the detection value of the third pressure sensor 43, and the detection value of the fourth pressure sensor 44 in each refrigerant circuit RC (each machine unit R1) in a state where the refrigerant circuit RC is operated. For example, in the refrigerant leakage circuit determination process, the refrigerant leakage determination section 84 determines the refrigerant leakage circuit according to the degree of pressure reduction of the high-pressure refrigerant. Further, alternatively/simultaneously, the refrigerant leakage determination section 84 determines the refrigerant leakage circuit based on the level of any/all of the following detection values: a detection value (suction temperature) of the first temperature sensor 21 of each refrigerant circuit RC; a detected value (discharge temperature) of the second temperature sensor; the detection value (condensing temperature/evaporating temperature) of the third temperature sensor 23; the detection value of the fourth temperature sensor 24; the detection value of the fifth temperature sensor 25; the detection value of the sixth temperature sensor 41; and a detection value of the seventh temperature sensor 42.

That is, the refrigerant leakage determination section 84 corresponds to a "refrigerant leakage detection section" that detects refrigerant leakage in the heat exchanger unit 30 (equipment machine room R) and determines a refrigerant leakage circuit (i.e., determines in which refrigerant circuit RC the refrigerant leakage has occurred) together with the refrigerant leakage sensor 70.

After the refrigerant leak determination unit 84 determines the refrigerant leak circuit, a bit corresponding to the refrigerant leak circuit is set in the refrigerant leak detection flag M6. Thus, when the refrigerant leakage occurs in the heat exchanger unit 30, the other functional units can grasp the fact that the refrigerant leakage has occurred and also grasp the refrigerant circuit RC in which the refrigerant leakage has occurred.

(6-5) machine control section 85

The device control unit 85 controls the operation of each device (for example, 11, 13, 16, 17, 20, 31, 32, 36, 46, 48, etc.) included in the heat load processing system 100 according to a control program and in some cases. The equipment control unit 85 controls the state of the ventilation device 200 (the ventilation fan 210 and the opening/closing mechanism 220) provided in the equipment room R. The device control unit 85 determines the control mode to be switched by referring to the control mode determination flag M5, and controls the operation of each device based on the determined control mode. The device control unit 85 receives requests from other functional units to control the operation of each device.

For example, in the normal operation mode, the device controller 85 controls the operation capacity of the compressor 11, the opening degrees of the heat-source-side fan 20, the heat-source-side first control valve 16, and the heat-source-side second control valve 17, the opening degree of the expansion valve 31, the rotation speed of the pump 36, and the like in real time to perform the normal cycle operation or the reverse cycle operation based on the set temperature, the detection values of the sensors, and the like.

In the normal cycle operation, the device control unit 85 controls the four-way selector valve 13 to the normal cycle state, and causes the heat source side heat exchanger 14 to function as a condenser (or radiator) of the refrigerant and causes the heat exchanger 33 of the heat exchanger unit 30 to function as an evaporator of the refrigerant. In the reverse cycle operation, the device controller 85 controls the four-way selector valve 13 to the reverse cycle state, and causes the heat source-side heat exchanger 14 to function as an evaporator of the refrigerant and the heat exchanger 33 of the heat exchanger unit 30 to function as a condenser (or radiator) of the refrigerant.

The device control unit 85 executes various controls described below according to the situation. The device control unit 85 is configured to be able to measure time.

< first control of refrigerant leakage >

When it is assumed that refrigerant leakage occurs in the heat exchanger unit 30 (refrigerant circuit RC), the machine control portion 85 executes the refrigerant leakage first control. The first refrigerant leakage control is a control in which the fans (the exhaust fan 46 and the cooling fan 48) disposed in the heat exchanger unit 30 are operated at a predetermined rotational speed to prevent a region where the concentration of the leaked refrigerant is locally high from being generated in the heat exchanger unit 30. In the first control of the refrigerant leakage, the device control unit 85 operates the exhaust fan 46 of the heat exchanger unit 30 at a predetermined rotational speed (air volume). In the first control of the refrigerant leakage, the device control unit 85 operates the cooling fan 48 of the heat exchanger unit 30 at a predetermined rotational speed (air volume). In the present embodiment, the rotation speeds of the exhaust fan 46 and the cooling fan 48 in the refrigerant leakage first control are set to the maximum rotation speed (maximum air volume). That is, in the first control of the refrigerant leakage, the device control unit 85 brings the exhaust fan 46 or the cooling fan 48 into an operating state when the fan is in a stopped state, and the device control unit 85 controls the rotational speed of the exhaust fan 46 or the cooling fan 48 to the maximum rotational speed when the fan is already in an operating state.

By the above-described first refrigerant leakage control, even if refrigerant leakage occurs in the heat exchanger unit 30, the leaked refrigerant is agitated in the heat exchanger unit 30 or discharged from the heat exchanger unit 30 by the first air flow AF1 generated by the exhaust fan 46 and the second air flow AF2 generated by the cooling fan 48. Therefore, the concentration of the leaking refrigerant in the heat exchanger unit 30 is suppressed from increasing.

< second control of refrigerant leakage >

When it is assumed that refrigerant leakage occurs in the heat exchanger unit 30 (refrigerant circuit RC), the machine control portion 85 executes the refrigerant leakage second control. The second refrigerant leakage control is a control for increasing the ventilation amount of the ventilator 200 to prevent a region where the concentration of the leaked refrigerant is high from being locally generated in the equipment room R.

In the second control of the refrigerant leakage, the device control unit 85 increases the rotation speed (air volume) of the ventilation fan 210. In the present embodiment, the rotational speed of the ventilation fan 210 in the second refrigerant leakage control is set to the maximum rotational speed (maximum air volume). That is, in the second refrigerant leakage control, when the ventilation fan 210 is in the stopped state, the apparatus control unit 85 brings the ventilation fan 210 into the operating state, and when the ventilation fan 210 is already in the operating state, the apparatus control unit 85 controls the rotational speed of the ventilation fan 210 to the maximum rotational speed. When the ventilation fan 210 is intermittently operated in the intermittent operation mode, the apparatus control unit 85 switches the second control for refrigerant leakage to the continuous operation mode, and continuously operates the ventilation fan 210. This increases the operation time per unit time of the ventilation fan 210. As a result, the ventilation amount of the ventilation fan 210 increases, and the discharge of the leaking refrigerant to the external space is promoted.

Further, the device control unit 85 switches the opening/closing mechanism 220 to the open state in the second control of the refrigerant leakage. Thereby, the equipment machine room R communicates with the other space. As a result, a part of the leaked refrigerant in the equipment room R flows out to another space, and the occurrence of a region in which the concentration of the leaked refrigerant is high in the equipment room R is further suppressed.

< third control of refrigerant leakage >

When it is assumed that refrigerant leakage occurs in the heat exchanger unit 30 (refrigerant circuit RC) (specifically, when the refrigerant leakage detection flag M6 is set up), the machine control portion 85 executes the refrigerant leakage third control. In the third control of the refrigerant leakage, the device control unit 85 controls the expansion valve 31 and the opening/closing valve 32 of the refrigerant leakage circuit (the refrigerant circuit RC in which the refrigerant leakage occurs) to be in the closed state. This suppresses the inflow of the refrigerant from the heat-source-side unit 10 into the refrigerant leakage circuit, and further suppresses the refrigerant leakage in the heat exchanger unit 30. That is, the third refrigerant leakage control is a control for suppressing the refrigerant leaking in the heat exchanger unit 30 from flowing out when the refrigerant leakage occurs.

In the third control of the refrigerant leakage, the device control portion 85 controls the refrigerant leakage circuit to a stopped state. That is, the respective devices (the compressor 11, the heat-source-side fan 20, and the like) of the refrigerant circuit RC in which the refrigerant leakage has occurred are stopped. Thereby, the inflow of the refrigerant into the refrigerant leakage circuit is further suppressed, so that further refrigerant leakage is suppressed.

In addition, the device control unit 85 keeps the devices of the refrigerant circuit RC in operation, which were operating when the refrigerant leakage detection flag M6 was set, in an operating state without stopping the devices. That is, in the third control of refrigerant leakage, the apparatus control unit 85 controls the refrigerant circuits RC other than the refrigerant leakage circuit among the refrigerant circuits RC (apparatus unit R1) that were in operation when refrigerant leakage was detected, to be in operation. This allows the refrigerant circuit RC, in which no refrigerant leakage occurs, to continue its operation.

(6-6) drive signal output section 86

The drive signal output unit 86 outputs a corresponding drive signal (drive voltage) to each device (for example, 11, 13, 16, 17, 20, 31, 32, 36, 46, 48, etc.) in accordance with the control content of the device control unit 85. The drive signal output unit 86 includes a plurality of inverters (not shown), and outputs a drive signal from a corresponding inverter to a specific device (for example, the compressor 11, the heat-source-side fan 20, the pump 36, or the like).

(6-7) information output control section 87

The information output control unit 87 is a functional unit that controls the operation of the output device 300. The information output control unit 87 outputs predetermined information to the output device 300 in order to output information on the operation state and the status to the user. For example, when the refrigerant leakage detection flag M6 is set, the information output control unit 87 causes the output device 300 to output information (refrigerant leakage notification information) notifying the fact that refrigerant leakage has occurred. The refrigerant leakage notification information is display information such as characters or sound information such as an alarm. This enables a manager or a user to grasp the fact that the refrigerant leakage has occurred, and to take a predetermined measure.

(7) Processing flow of the controller 80

An example of the processing flow of the controller 80 will be described below with reference to fig. 13. Fig. 13 is a flowchart showing an example of the processing flow of the controller 80. When the power is turned on, the controller 80 performs processing in the flow shown from step S101 to step S110 in fig. 13. The processing flow shown in fig. 13 is an example, and can be changed as appropriate. For example, the order of steps may be changed to the extent that no contradiction occurs, some steps may be executed in parallel with other steps, or other steps may be newly added.

If it is determined in step S101 that a refrigerant leak has occurred in the heat exchanger unit 30 (refrigerant circuit RC) (that is, if yes), the controller 80 proceeds to step S105. If the controller 80 determines that no refrigerant leakage has occurred in the heat exchanger unit 30 (i.e., if no), the process proceeds to step S102.

In step S102, when a command (operation start command) for instructing the start of operation is not input (that is, in the case of no), the controller 80 returns to step S101. On the other hand, when the operation start command is input (that is, yes), the controller 80 proceeds to step S103.

In step S103, the controller 80 shifts to the normal operation mode (or maintains the normal operation mode). Subsequently, the process proceeds to step S104.

In step S104, the controller 80 performs a forward cycle operation or a reverse cycle operation by controlling the state of each device in real time based on the input command, the set temperature, the detection value of each sensor (S1, S2, etc.), and the like. Then, the process returns to step S101.

In step S105, the controller 80 transitions to the refrigerant leakage mode. Then, the controller 80 proceeds to step S106.

In step S106, the controller 80 outputs the refrigerant leakage notification information to the output device 300 such as a remote controller. This enables the manager to recognize that the refrigerant leakage is occurring. Then, the controller 80 proceeds to step S107.

In step S107, the controller 80 executes the refrigerant leakage first control. Specifically, the controller 80 drives the exhaust fan 46 and the cooling fan 48 at a predetermined rotational speed (e.g., maximum rotational speed). Thus, in the heat exchanger unit 30, the agitation or discharge of the leaking refrigerant is promoted, and the leakage refrigerant is suppressed from locally reaching the dangerous concentration. Then, the controller 80 proceeds to step S108.

In step S108, the controller 80 executes the refrigerant leakage second control. Specifically, the controller 80 increases the ventilation amount (air volume and/or operation time per unit time) of the ventilation fan 210. This increases the amount of ventilation by the ventilation fan 210, and promotes the discharge of the leaked refrigerant into the external space. Further, the device control unit 85 switches the opening/closing mechanism 220 to the open state in the second control of the refrigerant leakage. This allows the equipment room R to communicate with the other space, thereby facilitating the discharge of the leaking refrigerant in the equipment room R and further suppressing the occurrence of a region where the concentration of the leaking refrigerant is high. Then, the controller 80 proceeds to step S109.

In step S109, the controller 80 executes a refrigerant leakage circuit determination process. Specifically, the controller 80 controls each refrigerant circuit RC (each equipment unit R1) to be in an operating state, and specifies a refrigerant leakage circuit (refrigerant circuit RC in which refrigerant leakage occurs) based on any/all of the detection values of each heat source side sensor S1 and each heat exchanger unit sensor S2. Then, the controller 80 proceeds to step S110.

In step S110, the controller 80 executes the refrigerant leakage third control. Specifically, the controller 80 controls the expansion valve 31 and the opening/closing valve 32 of the refrigerant leakage circuit (the refrigerant circuit RC in which the refrigerant leakage occurs) to be in a closed state. This suppresses the inflow of the refrigerant from the heat-source-side unit 10 into the refrigerant leakage circuit, and further suppresses the refrigerant leakage in the heat exchanger unit 30. Further, in the refrigerant leakage third control, the controller 80 controls the refrigerant leakage circuit to a stopped state. That is, the respective devices (the compressor 11, the heat-source-side fan 20, and the like) of the refrigerant circuit RC in which the refrigerant leakage has occurred are stopped. Thereby, the inflow of the refrigerant into the refrigerant leakage circuit is further suppressed, so that further refrigerant leakage is suppressed. That is, in the third control of refrigerant leakage, the controller 80 controls the refrigerant circuits RC other than the refrigerant leakage circuit among the refrigerant circuits RC (the machine unit R1) that were in operation when refrigerant leakage was detected to be in operation. This allows the refrigerant circuit RC, in which no refrigerant leakage occurs, to continue its operation. Then, the controller 80 returns to step S101.

(8) Refrigerant leakage countermeasure in thermal load handling system 100

In the heat load processing system 100, the countermeasure against the refrigerant leakage is realized by the following (i) to (iv).

(i)

In the heat load processing system 100, fans (the exhaust fan 46 and the cooling fan 48) for generating air flows (AF1, AF2) are disposed in the heat exchanger unit 30. When a refrigerant leak occurs in the heat exchanger unit 30, a first refrigerant leak control is executed to start the fan or increase the rotation speed (air volume) of the fan. Thereby, in the heat exchanger unit 30, the leaking refrigerant is stirred. Alternatively, the leaking refrigerant is discharged from the heat exchanger unit 30. As a result, the concentration of the leaking refrigerant is suppressed from increasing in the heat exchanger unit 30.

(ii)

In the heat load processing system 100, the controller 80 is configured to control the ventilator 200 (the ventilator fan 210 and the opening/closing mechanism 220) in the equipment room R in which the heat exchanger unit 30 is installed. When a refrigerant leak occurs in the heat exchanger unit 30, the second refrigerant leak control is executed, and the ventilation amount of the ventilator 200 is increased. Specifically, the ventilation amount (air volume, operation time per unit time) of the ventilation fan 210 increases. Further, the opening and closing mechanism 220 is switched to the open state. As a result, the amount of ventilation in the heat exchanger 30 increases, and agitation and discharge of the leaked refrigerant in the equipment room R are promoted. As a result, the concentration of the leaking refrigerant in the equipment room R is suppressed from increasing.

(iii)

In the heat load processing system 100, when refrigerant leakage in the heat exchanger unit 30 occurs, refrigerant leakage circuit determination processing is performed. Specifically, in the refrigerant leakage circuit determination process, each refrigerant circuit RC (each equipment unit R1) is controlled to be in an operating state, and a refrigerant leakage circuit (refrigerant circuit RC in which refrigerant leakage occurs) is determined based on any/all of the detection values of each heat source side sensor S1 and each heat exchanger unit sensor S2. Thus, in the heat load processing system 100 including the plurality of refrigerant circuits RC (the equipment units R1), the refrigerant circuit RC in which the refrigerant leakage occurs can be quickly specified.

In the heat load processing system 100, the expansion valve 31 and the opening/closing valve 32, which can switch between opening and closing, are disposed in the heat exchanger unit 30 so as to allow the refrigerant to flow from the heat source side unit 10 to the heat exchanger unit 30. Further, the configuration is: when the refrigerant leakage occurs in the heat exchanger unit 30, the refrigerant leakage third control is executed, and the expansion valve 31 and the opening/closing valve 32 of the refrigerant leakage circuit (the refrigerant circuit RC in which the refrigerant leakage occurs) are switched to the closed state. As a result, the flow of the refrigerant from the heat source unit 10 to the heat exchanger unit 30 is blocked, and further refrigerant leakage is suppressed.

In the third control for refrigerant leakage, the refrigerant leakage circuit is controlled to a stopped state. That is, the heat load processing system 100 is configured to stop the respective devices (the compressor 11, the heat source side fan 20, and the like) of the refrigerant circuit RC in which the refrigerant leakage has occurred. Thereby, the inflow of the refrigerant into the refrigerant leakage circuit is further suppressed, so that further refrigerant leakage is suppressed.

In the third control for refrigerant leakage, the respective devices of the refrigerant circuit RC that are operating when refrigerant leakage is detected are kept in operation without being stopped. That is, the heat load processing system 100 is configured to: in the third control of refrigerant leakage, the refrigerant circuits RC other than the refrigerant leakage circuit among the refrigerant circuits RC in operation at the time of detection of refrigerant leakage are controlled to be in operation. This allows the refrigerant circuit RC, in which no refrigerant leakage occurs, to continue its operation.

In this way, the heat load processing system 100 is configured to: in the third control of refrigerant leakage, the operation state of each refrigerant circuit RC is changed in accordance with the result of the refrigerant leakage circuit determination process.

(iv)

In the heat load processing system 100, the suction port 47a of the first air flow AF1 generated by the exhaust fan 46 is formed at a position lower than the uppermost portion a1 (the uppermost portion of the refrigerant pipe housed in the heat exchanger unit 30). Thus, when the refrigerant having a specific gravity greater than that of air leaks from the heat exchanger unit 30, the leakage refrigerant is discharged from the heat exchanger unit 30. That is, when the refrigerant having a specific gravity higher than that of air leaks from the heat exchanger unit 30, the leaked refrigerant accumulates in the space Si directly above the floor, but the discharge of the leaked refrigerant accumulating in the space Si directly above the floor is promoted because the suction port 47a of the first air flow AF1 is formed at a position lower than the uppermost portion a 1.

(9) Feature(s)

(9-1)

In the above embodiment, the casing 50 collectively houses a plurality of machine units R1 constituting different refrigerant circuits RC. The refrigerant leakage detection units (the refrigerant leakage sensor 70 and the refrigerant leakage determination unit 84) detect the refrigerant leakage in each of the equipment units R1 (i.e., in each of the refrigerant circuits RC housed in the heat exchanger unit 30). The controller 80 is configured to execute a refrigerant leakage circuit determination process (a first process) in which a refrigerant leakage circuit, which is a refrigerant circuit RC in which refrigerant leakage occurs, is determined, and a refrigerant leakage third control (a second process) in which an operation state of a predetermined refrigerant circuit RC is changed in accordance with a result of the refrigerant leakage circuit determination process, when refrigerant leakage is detected by the refrigerant leakage detecting unit (the refrigerant leakage sensor 70, the refrigerant leakage determining unit 84).

Thus, in the heat load processing system 100 including a plurality of refrigerant circuits RC (in particular, a plurality of machine units R1 in the same casing 50), it is possible to quickly identify the refrigerant circuit RC in which the refrigerant leakage has occurred. Further, the operation state of the predetermined refrigerant circuit RC can be changed according to the determination result.

(9-2)

In the above embodiment, the controller 80 is configured to control the refrigerant leak circuit to the stopped state in the third refrigerant leak control (second process). Thus, when the refrigerant leakage occurs, further leakage of the refrigerant from the refrigerant leakage circuit is suppressed.

(9-3)

In the above embodiment, the controller 80 is configured to: in the refrigerant leakage circuit determination process (first process), the refrigerant leakage circuit is determined by comparing the states of the refrigerant in the respective refrigerant circuits RC based on the detection values of the refrigerant state sensors (the heat source side sensor S1, the heat exchanger unit sensor S2). Thus, even when refrigerant leakage occurs in the heat exchanger unit, the leaked refrigerant can be easily discharged from the equipment room to another space.

(9-4)

In the above embodiment, the controller 80 is configured to: in the refrigerant leakage circuit determination process (first process), the refrigerant leakage circuit is determined in a state where each refrigerant circuit RC is operated.

(9-5)

In the above embodiment, the controller 80 is configured to: in the third control of refrigerant leakage (second process), the refrigerant circuits RC other than the refrigerant leakage circuit among the refrigerant circuits RC in the operating state when refrigerant leakage is detected by the refrigerant leakage detecting unit (the refrigerant leakage sensor 70, the refrigerant leakage determining unit 84) are controlled to be in the operating state. This allows the refrigerant circuit RC, in which no refrigerant leakage occurs, to continue its operation.

(10) Modification example

The above embodiment can be modified as appropriate as described in the modification examples below. Each modification may be combined with other modifications to the extent that no contradiction occurs.

(10-1) modification example 1

The heat exchanger unit 30 according to the above embodiment may be configured as the heat exchanger unit 30a shown in fig. 14 to 17. Next, differences between the heat exchanger unit 30a and the heat load processing system 100a including the heat exchanger unit 30a and the above-described embodiments will be mainly described. Note that, unless otherwise specified, descriptions of points common to the above embodiments will be omitted.

Fig. 14 is a perspective view of the heat exchanger unit 30 a. Fig. 15 is a schematic diagram showing an arrangement form of devices in the heat exchanger unit 30a in a plan view. Fig. 16 is a schematic diagram showing the arrangement of the devices in the heat exchanger unit 30a when viewed from the right. Fig. 17 is a schematic diagram showing an arrangement form of devices in the heat exchanger unit 30a in a front view. In fig. 17, reference numeral "a 1 '" denotes the highest portion (uppermost portion) of the refrigerant pipes included in the heat exchanger unit 30a, and reference numeral "h 1 '" denotes the height of the uppermost portion a1 '. Although fig. 15 to 17 illustrate an embodiment in which three refrigerant systems (refrigerant circuits RC) are arranged in the heat exchanger unit 30a, the idea of the present disclosure is not limited to the above-described embodiment. That is, the heat exchanger unit 30a may have four or more components of the refrigerant circuit RC, or may have less than three components of the refrigerant circuit RC.

The heat exchanger unit 30a includes the machines included in the heat source-side unit 10. More specifically, the heat exchanger unit 30a has a substantially rectangular parallelepiped housing 51, and the housing 51 houses therein the devices included in the heat source side unit 10 in addition to the devices included in the heat exchanger unit 30. In other words, in the heat exchanger unit 30a, the heat exchanger unit 30 and the heat-source-side unit 10 may be integrally configured. That is, the equipment unit R1 'including the first pipe P1-the eleventh pipe P11, the compressor 11, the accumulator 12, the four-way selector valve 13, the heat source side heat exchanger 14a (the second heat exchanger), the subcooler 15, the heat source side first control valve 16, the heat source side second control valve 17, and the like, in addition to the refrigerant flow path RP, the expansion valve 31, the opening/closing valve 32, and the refrigerant pipes Pa to Pd of the first heat exchanger 34 or the second heat exchanger 35, is housed in the casing 51 together with the other equipment units R1'.

The heat exchanger unit 30a includes a heat source side heat exchanger 14a instead of the heat source side heat exchanger 14. The heat source-side heat exchanger 14 is configured to exchange heat between the refrigerant and the heat source-side air flow, and the heat source-side heat exchanger 14a is configured to exchange heat between the refrigerant and a heat source-side heat medium (e.g., water). The type of the heat source-side heat exchanger 14a is not limited, and is, for example, a double-tube heat exchanger. However, the heat source side heat exchanger 14a may be appropriately selected as long as it is a heat exchanger of a heat exchanger type that can be used for the refrigerant and the heat source side heat medium. In the heat exchanger unit 30a, the heat-source-side fan 20 is omitted in association with heat exchange between the refrigerant and the heat-source-side heat medium (e.g., water). In connection with this, the heat load processing system 100a may be configured as shown in fig. 18, for example.

Fig. 18 is a schematic configuration diagram of the heat load processing system 100 a. In the heat load processing system 100a, a heat source side heat medium circuit WC is configured. The heat source-side heat medium flows through the heat source-side heat medium circuit WC, and exchanges heat with the refrigerant in the heat source-side heat exchanger 14 a. The heat source-side heat medium circuit WC includes a cooling tower 90 for cooling the heat source-side heat medium heated by heat exchange with the refrigerant in the heat source-side heat exchanger 14 by the cooling tower 90. The cooling tower 90 is installed on a roof, for example. In the heat source-side heat medium circuit WC, a plurality of heat source-side pumps 92 for feeding the heat source-side heat medium to the heat source-side heat exchanger 14 are arranged in parallel in accordance with the number of the heat source-side heat exchangers 14.

In the heat load processing system 100a, the liquid-side communication pipe LP and the gas-side communication pipe GP are omitted in association with the respective devices included in the heat source-side unit 10.

In the heat load processing system 100a, the refrigerant may be heated in the heat source-side heat exchanger 14a by the heat source-side heat medium. In this case, another device may be provided instead of or together with the cooling tower 90.

In the heat load processing system 100a, the same operational effects as those of the above-described embodiment (for example, the operational effects (i) to (iv) described above) can be achieved in the same manner as the heat exchanger unit 30.

For example, the same operations and effects as those in (i) to (iii) described above are achieved by configuring the controller 80 to execute the same controls as the refrigerant leakage first control, the refrigerant leakage second control, the refrigerant leakage third control, and the refrigerant leakage circuit determination process.

In the above case, the controller 80 may be configured to: in the refrigerant leakage circuit determination process (first process), the refrigerant leakage circuit is determined from any/all detection values of the refrigerant state sensors (S1, S2) in the respective refrigerant circuits RC in a state in which the expansion valve 31 and the opening/closing valve 32 of the respective machine units R1 are controlled to be in a closed state and the respective compressors 11 are controlled to be stopped (that is, the respective refrigerant circuits RC are controlled to be stopped). That is, since the heat exchanger unit 30a houses the heat source side equipment in common, it is preferable to stop each refrigerant circuit RC immediately if the evacuation operation is not particularly effective and if a refrigerant leak is detected.

In the above case, the controller 80 is configured to determine the refrigerant leakage circuit in accordance with the degree of pressure decrease of the high-pressure refrigerant in each refrigerant circuit RC (each machine unit R1') in the refrigerant leakage circuit determination process (first process), thereby facilitating the determination of the refrigerant leakage circuit.

For example, the same operational effects as those in (iv) above can be obtained by providing the exhaust fan unit 45 such that the suction port 47a of the first air flow AF1 is disposed at a position lower than the uppermost portion a 1' (the uppermost portion of the refrigerant pipes included in the heat exchanger unit 30 a).

In the heat exchanger unit 30a, a second exhaust fan 46a (see fig. 17) may be provided instead of or together with one or both of the exhaust fan unit 45 and the cooling fan 48. The second exhaust fan 46a is disposed in the vicinity of the heat medium pipe (Ha-Hd) of the heat exchanger unit 30 a. The second exhaust fan 46a generates a third air flow AF3 flowing out from the heat exchanger unit 30a to the outside (equipment machine room R). In the first control of the refrigerant leakage, the second exhaust fan 46a may be controlled to enter the operating state or to increase the rotation speed (air volume). By providing the second exhaust fan 46a as described above and controlling the second exhaust fan 46a in the first control of refrigerant leakage, the operational effect of the above-described (i) is more remarkably achieved. In particular, by disposing the second exhaust fan 46a near the heat medium pipe (Ha-Hd), the leakage refrigerant is suppressed from flowing to the living space SP side through the heat medium pipe Ha-Hd.

(10-2) modification example two

The devices constituting the controller 80 (particularly, the device controller 85) of the above-described embodiment may be disposed in the heat source-side unit 10 or the heat exchanger unit 30. That is, the controller 80 (particularly, the device controller 85) may be configured by only the heat source-side unit controller 29 or the heat exchanger-unit controller 49.

(10-3) modification III

Some or all of the devices constituting the controller 80 of the above embodiment need not be disposed in the heat source-side unit 10 or the heat exchanger unit 30, and may be disposed in other places. For example, a part or all of the controller 80 may be disposed at a remote location configured to be able to communicate with the devices controlled by the controller 80. That is, a part or all of the devices controlled by the controller 80 may be configured to be remotely controllable.

(10-4) modification example four

The cooling fan 48 of the above embodiment is not essential and can be omitted as appropriate. In the above case, the exhaust fan 46 of the above embodiment may also function as the cooling fan 48. That is, the exhaust fan 46 may be configured to cool the heat generating components of the heat exchanger unit control portion 49 by the first air flow AF 1.

(10-5) modification example five

In the above embodiment, the controller 80 is configured to: when a refrigerant leak is detected in the heat exchanger unit 30, the intermittently operated ventilation fan 210 is continuously operated in the first refrigerant leak control. From the viewpoint of increasing the amount of ventilation in the equipment room R, it is preferable to continuously operate the ventilation fan 210. However, in the first control of the refrigerant leakage, it is not necessarily required to continuously operate the ventilation fan 210 as long as the operation time per unit time of the ventilation fan 210 is increased.

(10-6) modification six

In the above embodiment, the suction port 47a of the first air flow AF1 is disposed at a position lower than the lowermost portion a2 (the lowermost portion of the refrigerant pipe housed in the heat exchanger unit 30). However, the suction port 47a may be disposed at a position higher than the lowermost portion a2 as long as it is disposed below the uppermost portion a1 (the uppermost portion of the refrigerant pipes housed in the heat exchanger unit 30).

(10-7) modification seven

One end (suction port 47a) of the flow passage forming member 47 of the exhaust fan unit 45 may be connected to the discharge port 58a of the bottom plate 58. That is, the discharge port 58a of the water collection tray may also function as the suction port 47a of the first air flow AF 1. In the above case, it can also be said that the suction port 47a of the first air flow AF1 is formed in the bottom plate 58 (water collection tray).

(10-8) modified example eight

The number and arrangement of the components disposed in the heat exchanger unit 30, such as the refrigerant pipes Pa to Pd, the heat medium pipes Ha to Hd, the expansion valve 31, the opening/closing valve 32, the heat exchanger 33, and the pump 36, are not limited to those illustrated in the above embodiments, and may be changed as appropriate depending on the installation environment and design specifications.

(10-9) modified example nine

In the above embodiment, the heat exchanger 33 has the first heat exchanger 34 and the second heat exchanger 35. However, this is merely an example, and the heat exchanger 33 may have three or more heat exchangers. For example, the heat exchanger 33 may be a single heat exchanger having the same number of refrigerant flow paths RP as the number of refrigerant circuits RC. The heat exchanger 33 may further include a plurality of heat medium flow paths HP connected in parallel in the heat medium circuit HC.

(10-10) modification ten

The configuration of the refrigerant circuit RC in the above embodiment can be changed as appropriate depending on the design specifications and the installation environment. Specifically, in the refrigerant circuit RC, other devices such as a reservoir and a valve may be disposed instead of or together with the device shown in fig. 1. Further, instead of the expansion valve 31 of the above embodiment, another expansion mechanism may be employed. For example, a mechanical expansion valve, a capillary tube, or the like may be used instead of the expansion valve 31.

(10-11) modification eleventh

In the above embodiment, a plurality of (here, four) refrigerant circuits RC are configured in parallel with the plurality of heat source-side units 10. In other words, in the heat load processing system 100, a plurality of refrigerant circuits RC are configured by the plurality of heat source-side units 10 and the heat exchanger unit 30. However, the number of the refrigerant circuits RC may not be the same as the number of the heat source side units 10. The number of heat source side units 10 connected to the heat exchanger unit 30 may be appropriately selected according to the installation environment and design specifications.

(10-12) modification twelve

The heat load processing system 100 of the above embodiment is configured to perform the forward cycle operation and the reverse cycle operation. However, the heat load processing system 100 does not necessarily need to be configured in the above-described manner. That is, the heat load processing system 100 may be configured as a device that performs only one of the forward cycle operation and the reverse cycle operation. In the above case, the four-way selector valve 13 may be omitted as appropriate.

(10-13) modification thirteen

In the above embodiment, the heat load processing system 100 is an air conditioning system that performs air conditioning of the living space SP. However, the heat load processing system 100 need not be an air conditioning system, but may be other systems. For example, the heat load processing system 100 may be applied to a hot water supply system, a heat storage system, or the like.

That is, the use-side unit 60 is not limited to a unit for air-conditioning the living space SP, and may be various types of equipment for cooling and heating processing machines or products using the heat medium cooled and heated in the heat exchanger unit 30.

The use-side unit 60 may be a tank that stores the heat medium cooled/heated in the heat exchanger unit 30. In the above case, the heat medium stored in the tank is sent to a device that is cooled and heated by the heat medium, for example, by a pump not shown.

(10-14) modifications fourteen

In the above embodiment, the refrigerant leak sensor 70 is disposed in the space Si directly above the floor in the heat exchanger unit 30. However, the arrangement form of the refrigerant leakage sensor 70 is not necessarily limited thereto, and may be appropriately changed according to the installation environment and the design specification.

For example, the refrigerant leak sensor 70 may be disposed above the floor space Si in the heat exchanger unit 30. The refrigerant leakage sensor 70 does not necessarily need to be disposed in the heat exchanger unit 30. For example, the refrigerant leakage sensor 70 may be disposed in the equipment room R separately from the heat exchanger unit 30, or may be disposed independently.

(10-15) modification fifteen

In the above embodiment, the refrigerant leakage sensor 70 is disposed in the heat exchanger unit 30, and the presence or absence of refrigerant leakage in the heat exchanger unit 30 is detected by determining the presence or absence of refrigerant leakage in the controller 80 (refrigerant leakage determination unit 84) based on a signal transmitted from the refrigerant leakage sensor 70. However, the detection mode of the refrigerant leakage is not necessarily limited thereto, and can be appropriately changed according to the installation environment and the design specification.

For example, the controller 80 (the refrigerant leakage determination unit 84) may be configured to detect whether or not there is a refrigerant leakage in the heat exchanger unit 30 based on any one of the detection values of the heat source side sensors S1 and/or the heat exchanger unit sensors S2. In this case, the refrigerant leakage sensor 70 may be omitted as appropriate.

(10-16) modified example sixteenth

In the above embodiment, in the second refrigerant leakage control, the operation of the ventilation fan 210 and the opening/closing mechanism 220 is controlled so as to increase the ventilation amount of the ventilator 200 in the equipment room R. In order to achieve the effect (ii) described above, it is preferable that the second control of refrigerant leakage is executed in the form of the above-described embodiment. However, in the second control of the refrigerant leakage, only the operation of one of the ventilation fan 210 and the opening/closing mechanism 220 may be controlled. In this case, since the amount of ventilation in the equipment room R is increased, the above-described action and effect (ii) are also exhibited.

(10-17) modification seventeen

In the above-described embodiment, in order to achieve the effects of (i) and (ii), it is preferable that the refrigerant leakage first control and the refrigerant leakage second control be executed together with the refrigerant leakage third control. However, in the idea of the present disclosure, the refrigerant leakage first control and the refrigerant leakage second control are not essential and may be omitted as appropriate.

(10-18) modified example eighteen

The order of execution of the refrigerant leakage first control, the refrigerant leakage second control, the refrigerant leakage third control, and the refrigerant leakage circuit determination process in the above-described embodiments can be changed as appropriate. For example, the refrigerant leakage circuit determination process and/or the third refrigerant leakage control may be executed before the first refrigerant leakage control and/or the second refrigerant leakage control.

(10-19) modification nineteen

In the above embodiment, the four machine units R1 are collectively housed in the casing 50. However, the number of the machine units R1 housed in the housing 50 can be changed as appropriate. The housing 50 may house five or more machine units R1, and may house three or less machine units R1.

(10-20) modification twenty

In the above embodiment, the controller 80 is configured to: in the refrigerant leakage circuit determination process (first process), the refrigerant leakage circuit is determined in a state where each refrigerant circuit RC is operated. However, the refrigerant leak circuit determination process is not necessarily limited to the embodiment described above, and can be appropriately changed according to the design specifications and installation environment. For example, the controller 80 may be configured to: in the refrigerant leakage circuit determination process (first process), the expansion valve 31 and the opening/closing valve 32 of each equipment unit R1 are controlled to be in the closed state, each compressor 11 is operated, the evacuation operation for recovering the refrigerant to the heat source side equipment unit 10 is performed in each refrigerant circuit RC, and after the evacuation operation is completed, the refrigerant leakage circuit is determined based on any/all detection values of the refrigerant state sensors (S1, S2) in each refrigerant circuit RC.

For example, the controller 80 may be configured to: in the refrigerant leakage circuit determination process (first process), the refrigerant leakage circuit is determined based on any/all detection values of the refrigerant state sensors (S1, S2) in the respective refrigerant circuits RC in a state in which the expansion valve 31 and the opening/closing valve 32 of the respective machine units R1 are controlled to be in a closed state and the respective compressors 11 are controlled to be in a stopped state (that is, the respective refrigerant circuits RC are controlled to be in a stopped state).

(10-21) modification twenty-one

In the above embodiment, when the refrigerant leakage occurs in the heat exchanger unit 30, the controller 80 may stop the operation of the pump 36 until the refrigerant leakage circuit is determined in the first refrigerant leakage control, the second refrigerant leakage control, or the refrigerant leakage circuit determination process. Thus, when refrigerant leakage occurs in the heat exchanger 33, the leaked refrigerant is prevented from flowing to the usage-side unit 60 (living space SP) side via the heat medium circuit HC.

(10-22) modification twenty-two

In the above-described embodiment, in the third control of the refrigerant leakage, the controller 80 includes the following controls of (a) to (c) that change the operation state of any of the refrigerant circuits RC according to the result of the refrigerant leakage circuit determining process.

(a) The expansion valve 31 and the opening/closing valve 32 of the refrigerant leakage circuit (refrigerant circuit RC in which refrigerant leakage occurs) are switched to a closed state.

(b) The refrigerant leakage circuit is controlled to a stopped state. That is, the respective devices (the compressor 11, the heat-source-side fan 20, and the like) of the refrigerant circuit RC in which the refrigerant leakage occurs are stopped.

(c) The respective devices of the refrigerant circuit RC, which are operating when the refrigerant leakage is detected, are not stopped but are kept in operation. That is, in the third refrigerant leakage control, the refrigerant circuits RC other than the refrigerant leakage circuit among the refrigerant circuits RC in operation at the time of detection of refrigerant leakage are controlled to be in operation.

Preferably, all of the controls of the above-described (a) to (c) are executed in the third control of the refrigerant leakage. However, in the third control of refrigerant leakage, it is not necessary to perform all of the above-described controls (a) to (c) as long as at least one of the above-described controls (a) to (c) is performed. That is, in the third refrigerant leakage control, only any one of the above-described (a) to (c) may be executed as long as the operation state of at least one refrigerant circuit RC is changed in accordance with the result of the refrigerant leakage circuit determining process.

(11)

While the embodiments have been described above, it should be understood that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Industrial applicability of the invention

The present disclosure can be used in thermal load handling systems.

Description of the symbols

10: a heat source side unit;

11: a compressor;

12: a storage tank;

13: a four-way reversing valve;

14. 14 a: a heat source side heat exchanger (second heat exchanger);

15: a subcooler;

16: a heat source side first control valve;

17: a heat source side second control valve;

18: a liquid side stop valve;

19: a gas side shutoff valve;

20: a heat source-side fan;

21-25: first to fifth temperature sensors (refrigerant state sensors);

27: a first pressure sensor (refrigerant state sensor);

28: a second pressure sensor (refrigerant state sensor);

29: a heat source side unit control section;

30. 30 a: a heat exchanger unit;

31: an expansion valve;

32: an opening and closing valve;

33: a heat exchanger;

34: a first heat exchanger;

35: a second heat exchanger;

36: a pump;

41: a sixth temperature sensor (refrigerant state sensor);

42: a seventh temperature sensor (refrigerant state sensor);

43: a third pressure sensor (refrigerant state sensor);

44: a fourth pressure sensor (refrigerant state sensor);

45: an exhaust fan unit;

46: an exhaust fan;

46 a: a second exhaust fan;

47: a flow path forming member;

47 a: a suction inlet;

48: a cooling fan;

49: a heat exchanger unit control unit;

50: a housing;

50 a: an outlet port;

51: a housing;

55: electrical component box

58: a base plate;

58 a: a discharge port;

60: a utilization side unit;

70: a refrigerant leakage sensor (refrigerant leakage detecting section);

80: a controller (control unit);

80a, 80 b: an adapter;

81: a storage unit;

82: an input control unit;

83: a mode control unit;

84: a refrigerant leakage determination unit (refrigerant leakage detection unit);

85: a device control unit (control unit);

86: a drive signal output section;

87: an information output control unit;

90: a cooling tower;

92: a heat source-side pump;

100. 100 a: a thermal load handling system;

200: a ventilation device;

210: a ventilation fan;

220: an opening and closing mechanism;

300: an output device;

581: a bottom surface portion;

a1, a 1': an uppermost portion;

a2: the lowest part;

AF 1: a first air stream;

AF 2: a second air stream;

AF 3: a third air stream;

b1: a building;

d: a ventilation duct;

GP: a gas-side communicating pipe;

h1: a first heat medium communication pipe;

h2: a second heat medium communication pipe;

HC: a heat medium circuit;

HP: a heat medium flow path;

Ha-Hd: a heat medium pipe;

and (3) LP: a liquid-side communicating tube;

P1-P11: first to eleventh piping;

pa, Pb, Pc, Pd: a refrigerant pipe;

r: an equipment machine room;

r1, R1': machine units (refrigerant systems constitute machines);

RC: a refrigerant circuit (refrigerant system);

RP: a refrigerant flow path;

s1: a heat source side sensor (refrigerant state sensor);

s2: heat exchanger train sensors (refrigerant condition sensors); SP: a living space; sa: a lower space;

sb: an upper space;

si: a space directly above the bottom plate;

WC: a heat source side heat medium circuit.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2006-38323.

Claims

1. A thermal load handling system (100, 100a) having a plurality of refrigerant systems for circulating a refrigerant, comprising:

a plurality of refrigerant system-constituting devices (R1, R1') each including a compressor (11) for compressing a refrigerant and/or a heat exchanger (33) connected to refrigerant pipes (Pb, Pc) through which the refrigerant flows and heat medium pipes (Hb, Hc, Hd) through which a heat medium flows, and exchanging heat between the refrigerant and the heat medium, as devices constituting one refrigerant system (RC);

a housing (50, 51) that houses a plurality of refrigerant system configuration devices that configure different refrigerant systems;

refrigerant leakage detection units (70, 84) that individually detect refrigerant leakage of the respective refrigerant systems; and

a control unit (80) that controls the operation of the actuator of each refrigerant system,

the control unit executes a first process in which a refrigerant leakage system, which is the refrigerant system in which refrigerant leakage is occurring, is determined and a second process in which the operating state of at least one of the refrigerant systems is changed in accordance with the result of the first process, when the refrigerant leakage detection unit detects refrigerant leakage.

2. The thermal load handling system (100, 100a) of claim 1,

in the second process, the control portion controls the refrigerant leak system to a stopped state.

3. The thermal load handling system (100, 100a) of claim 1 or 2,

the heat load handling system further includes refrigerant state sensors (S1, S2) that detect a pressure or a temperature of refrigerant in each of the refrigerant systems,

in the first process, the control portion compares the states of the refrigerants in the respective refrigerant systems based on the detection values of the refrigerant state sensors, thereby determining the refrigerant leakage system.

4. The thermal load processing system (100, 100a) according to any one of claims 1 to 3,

in the first process, the control portion may determine the refrigerant leakage system in a state where each of the refrigerant systems is operated.

5. The thermal load processing system (100, 100a) according to any one of claims 1 to 3,

in the first process, the control portion may determine the refrigerant leakage system in a state where each of the refrigerant systems is stopped.

6. The thermal load handling system (100a) of claim 5,

the refrigerant system constituting machine (R1') further comprises a second heat exchanger (14a) that condenses or dissipates the heat of the refrigerant compressed in the compressor by heat exchange with water,

in the first process, the control portion determines the refrigerant leakage system according to a degree of pressure reduction of the high-pressure refrigerant in each of the refrigerant systems.

7. The thermal load handling system (100, 100a) according to any one of claims 1 to 6,

in the second process, the control portion may control the refrigerant systems other than the refrigerant leakage system, among the refrigerant systems that are in an operating state when the refrigerant leakage is detected by the refrigerant leakage detecting portion, to be in an operating state.