Ventilation device, indoor unit, and air conditioner

Abstract

One aspect of a ventilation device according to the present disclosure comprises: a protective enclosure that internally houses at least a portion of a refrigerant circuit through which a refrigerant circulates; an intake port that takes in outside air into the protective enclosure; an exhaust port that discharges gas from the interior of the protective enclosure; and a fan that generates airflow that proceeds from the intake port, through the interior of the protective enclosure, and is exhausted from the exhaust port. The exhaust direction at the exhaust port is a direction different from the intake direction at the intake port, and the placement of the exhaust port is optimized according to the velocity U of gas drawn in from the exhaust port and the density ρ1 of refrigerant gas.

Description

Ventilation equipment, indoor units, and air conditioners

[0001] The present disclosure relates to a ventilation device, an indoor unit, and an air conditioner.

[0002] Conventionally, in a heat source unit using a flammable refrigerant, a fan is provided to ventilate the interior of an electrical component box in order to prevent refrigerant gas from accumulating in the electrical component box (for example, see Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2016-191505

[0004] Generally, the density of refrigerant gas differs from that of air, so it can accumulate at the top or bottom of the enclosure, causing localized increases in concentration. Depending on the placement of the fan inside the enclosure, this can be inefficient at dealing with concentration variations caused by the difference in density between air and refrigerant gas, resulting in long ventilation times.

[0005] In view of the above circumstances, one of the objects of the present disclosure is to provide a ventilation device that can improve ventilation efficiency inside a housing, and an indoor unit and an air conditioner that have such a ventilation device.

[0006] One aspect of the ventilation device according to the present disclosure includes a protective housing that houses at least a portion of a refrigerant circuit in which a refrigerant circulates, an intake port that takes in outside air into the protective housing, an exhaust port that exhausts gas from the inside of the protective housing, and a fan that generates an air flow that passes from the intake port through the inside of the protective housing and is exhausted from the exhaust port, wherein the exhaust direction at the exhaust port is different from the intake direction at the intake port, and the density of the refrigerant gas vaporized from the refrigerant is higher than the density of air, and １ , g, U, ρ １ , ρ ０ , η satisfies the following relationship (Equation 1). １ [m]: Distance from the bottom surface of the protective housing to the center of the exhaust port g [m / s ２ ]: Gravitational acceleration 9.8 U [m / s]: Wind speed of gas sucked through the exhaust port ρ １ [kg / m ３ ]: density ρ of the refrigerant gas ０ [kg / m ３ ]: Density of air η: Constant 3.27

[0007] One aspect of the ventilation device according to the present disclosure includes a protective housing that houses at least a portion of a refrigerant circuit in which a refrigerant circulates, an intake port that takes in outside air into the protective housing, an exhaust port that exhausts gas from the inside of the protective housing, and a fan that generates an air flow that passes from the intake port through the inside of the protective housing and is exhausted from the exhaust port, wherein the exhaust direction at the exhaust port is different from the intake direction at the intake port, and the density of the refrigerant gas vaporized from the refrigerant is lower than the density of air, and ２ , g, U, ρ １ , ρ ０ , η satisfies the following relationship (Equation 2). ２ [m]: Distance from the top surface of the protective housing to the center of the exhaust port g [m / s ２ ]: Gravitational acceleration 9.8 U [m / s]: Wind speed of gas sucked through the exhaust port ρ １ [kg / m ３ ]: density ρ of the refrigerant gas ０ [kg / m ３ ]: Density of air η: Constant 3.27

[0008] One aspect of an indoor unit according to the present disclosure includes the above-described ventilation device, at least a part of the refrigerant circuit, and a heat medium heat exchanger that is disposed inside the protective housing and exchanges heat between the refrigerant and a heat medium different from the refrigerant.

[0009] One aspect of an air conditioner according to the present disclosure includes the indoor unit described above, and an outdoor unit having at least a part of the refrigerant circuit and an outdoor heat exchanger that exchanges heat between the refrigerant and outside air.

[0010] According to the present disclosure, it is possible to provide a ventilation device that can improve ventilation efficiency inside a housing, as well as an indoor unit and an air conditioner that have such a ventilation device.

[0011] 1 is a schematic diagram showing the configuration of a geothermal heat pump system according to embodiment 1. FIG. 2 is a perspective view showing each device of an indoor unit housed in a protective housing according to embodiment 1. FIG. 3 is a perspective view of a refrigerant sensor according to embodiment 1. FIG. 4 is a schematic diagram of a ventilation device according to embodiment 1. FIG. 5 is a graph summarizing test results. FIG. 6 is a schematic diagram of a ventilation device according to embodiment 2. FIG. 7 is a schematic diagram showing the configuration of an air conditioner according to embodiment 3.

[0012] First Embodiment FIG. 1 is a schematic diagram showing a configuration of a geothermal heat pump system 1 according to a first embodiment.

[0013] The geothermal heat pump system 1 is connected to a geothermal heat exchanger 23 buried underground and an indoor load 30. The geothermal heat pump system 1 uses a heat pump to extract heat from the ground via a primary circuit C1 having the geothermal heat exchanger 23, and supplies the heat to the load 30 connected to a secondary circuit C2.

[0014] As will be described later, the load 30 in this embodiment includes a heating and cooling device 30a. Therefore, the geothermal heat pump system 1 functions as an air conditioner that adjusts the temperature of air in a room by utilizing geothermal energy.

[0015] In this embodiment, brine circulates through the primary circuit C1, and water circulates through the secondary circuit (heat medium circuit) C2. Note that the heat medium flowing through the primary circuit C1 and the heat medium flowing through the secondary circuit C2 may be liquid fluids.

[0016] The geothermal heat pump system 1 of this embodiment comprises an indoor unit 2, a primary circuit C1, a geothermal heat exchanger 23, a secondary circuit C2, a load 30, and a remote controller 42 operated by a user.

[0017] The indoor unit 2 is installed inside a building and includes an outer casing 2a, a heat pump unit 20A, a primary supply unit 20B, a secondary supply unit 20C, a control device 41, and a ventilation device 10.

[0018] The internal space B of the outer casing 2a of the indoor unit 2 accommodates the various components of the indoor unit 2 (heat pump unit 20A, primary supply unit 20B, secondary supply unit 20C, control unit 41, and ventilation device 10). As will be described later, the ventilation device 10 has a protective casing 10k. Some of the devices arranged inside the outer casing 2a are further arranged inside the protective casing 10k.

[0019] The heat pump unit 20A operates in a heat pump cycle and includes a primary heat exchanger 15, a four-way valve 12, a compressor 11, a secondary heat exchanger (heat medium heat exchanger) 13, an expansion valve 14, and refrigerant piping that connects these elements to form a refrigerant circuit CR.

[0020] Brine from the primary side circuit C1 flows into the primary side heat exchanger 15. The primary side heat exchanger 15 exchanges heat between the brine and the refrigerant in the refrigerant circuit CR. Water (heat medium) from the secondary side heat exchanger 13 flows into the secondary side heat exchanger 13. The secondary side heat exchanger 13 exchanges heat between the water in the secondary side circuit C2 and the refrigerant in the refrigerant circuit CR. The compressor 11 circulates the refrigerant through the refrigerant circuit CR. The expansion valve 14 reduces the pressure of the refrigerant. In this embodiment, the expansion valve 14 is an electronic expansion valve whose opening is variably controlled. The four-way valve 12 is disposed in a portion of the refrigerant circuit CR that is connected to the discharge side of the compressor 11. The four-way valve 12 can reverse the direction of the refrigerant flowing through the refrigerant circuit CR by switching a portion of the refrigerant circuit CR.

[0021] Examples of the refrigerant flowing through the refrigerant circuit CR include fluorine-based refrigerants or hydrocarbon-based refrigerants with low global warming potential (GWP). Examples of the refrigerant include a single refrigerant such as R1234yf, R1234ze, R32, or R290, a mixture of two or more of these, or a mixture of any of these with other refrigerants. Examples of the refrigerant include a mixture of R1132(E) or R1123. Examples of the refrigerant include a mixture of R516A, R445A, R444A, R454C, R444B, R454A, R455A, R457A, R459B, R452B, R454B, R447B, R447A, R446A, and R459A.

[0022] A flammable refrigerant, for example, circulates in the refrigerant circuit CR. In this specification, the term "flammable" also includes slightly flammable refrigerant. The refrigerant vaporizes when exposed to atmospheric pressure. In the following description, the refrigerant vaporized at atmospheric pressure is referred to as refrigerant gas. The density of refrigerant gas is higher than that of air. In other words, refrigerant gas is heavier than air and accumulates below the air in a space filled with air.

[0023] The primary-side supply device 20B controls the circulation of brine in the primary-side circuit C1 and includes a primary-side pump 21, a primary-side flow rate sensor 22, and a portion of the piping that constitutes the primary-side circuit C1.

[0024] The primary pump 21 pumps the brine to supply it to the underground heat exchanger 23. The primary flow rate sensor 22 measures the flow rate of the brine circulating through the primary circuit C1. The primary circuit C1 may be provided with a temperature sensor that measures the temperature of the brine flowing into the primary heat exchanger 15 (inlet temperature) and a temperature sensor that measures the temperature of the brine flowing out of the primary heat exchanger 15 (outlet temperature).

[0025] In addition to the primary pump 21 and the primary flow rate sensor 22 that constitute the primary supply device 20B, the primary heat exchanger 15 and the underground heat exchanger 23 are connected to the primary circuit C1. The underground heat exchanger 23 is installed underground and exchanges heat between the brine and the ground G, which is a heat source. For example, when the temperature underground is higher than the outside air temperature, the brine absorbs the heat underground and is heated. The underground heat exchanger 23 is, for example, a borehole or a horizontal loop. The primary circuit C1 may be connected to multiple underground heat exchangers.

[0026] The secondary-side supply device 20C supplies hot water to the load 30. The secondary-side supply device 20C includes a secondary-side pump 31, an electric heater 33, a secondary-side flow rate sensor 32, a flow path switching device 34, and a portion of the piping that constitutes the secondary-side circuit C2.

[0027] The secondary pump 31 circulates water through the refrigerant circuit CR. The electric heater 33 further heats the hot water heated and generated in the secondary heat exchanger 13 during heating. The flow path switching device 34 is, for example, a three-way valve. The secondary flow rate sensor 32 measures the flow rate of water circulating through the refrigerant circuit CR. The primary circuit C1 may be provided with a temperature sensor that measures the temperature of the water flowing into the secondary heat exchanger 13 (outlet temperature) and a temperature sensor that measures the temperature of the generated hot water (return temperature).

[0028] In addition to the secondary pump 31, electric heater 33, secondary flow rate sensor 32, and flow path switching device 34 that constitute the secondary supply device 20C, the secondary circuit C2 is connected to the secondary heat exchanger 13 and the load 30.

[0029] In this embodiment, the load 30 includes a water storage tank 30b that supplies hot water to a bath or the like, and a heating and cooling device 30a. The water stored in the water storage tank 30b exchanges heat with water (hot water or coolant) flowing through the secondary circuit C2. This causes the water in the water storage tank 30b to be heated or cooled. The water stored in the water storage tank 30b can also be used for a bath or the like as needed. The heating and cooling device 30a cools or heats a room using the water (hot water or coolant) flowing through the secondary circuit C2.

[0030] The secondary circuit C2 branches at a flow path switching device 34 located downstream of the secondary heat exchanger 13 and the electric heater 33. The branched pipes extend to the water storage tank 30b and the air conditioning device 30a, respectively. The pipes returning from the water storage tank 30b and the air conditioning device 30a merge again. That is, the flow path switching device 34 switches the circulation destination of the hot water between the water storage tank 30b and the air conditioning device 30a.

[0031] The control device 41 controls the operation of the entire geothermal heat pump system 1. The control device 41 is connected to a remote controller 42 by wire or wirelessly, and operation commands from the user are input to the control device 41 via the remote controller 42. In addition, the control device 41 receives measurement information measured by multiple sensors that detect the operating state of the primary side circuit C1 and multiple sensors that detect the operating state of the refrigerant circuit CR.

[0032] The control device 41 controls the refrigerant circuit CR, the primary side circuit C1, and the refrigerant circuit CR based on input operation commands, measurement information, etc. Specifically, the control device 41 controls the operating frequency of the compressor 11, the opening degree of the expansion valve 14, the rotation speed of the primary side pump 21, the rotation speed of the secondary side pump 31, and the power supply to the electric heater 33 based on the measurement information, etc., so that the hot water required by the load 30 is supplied. The control device 41 also controls the switching of the flow path switching device 34 based on the operation command. The control device 41 is also connected to the refrigerant sensor 16 and the fan 17. The control device 41 operates the fan 17 when the refrigerant sensor 16 detects refrigerant gas.

[0033] The control device 41 can also switch the operation mode of the geothermal heat pump system 1 between a heating / hot water supply operation mode and a cooling operation mode.

[0034] In the heating and hot water supply operation mode, the control device 41 operates the four-way valve 12 to control the refrigerant circulation direction in the refrigerant circuit CR. In the heating operation mode, high-temperature, high-pressure gas refrigerant discharged from the compressor 11 flows through the four-way valve 12 into the secondary-side heat exchanger 13. The high-temperature, high-pressure gas refrigerant exchanges heat with water flowing through the secondary-side circuit C2 in the secondary-side heat exchanger 13, condensing and liquefying it while releasing heat, becoming high-pressure liquid refrigerant. The heat released from the refrigerant is imparted to water flowing through the secondary-side circuit C2 on the load 30 side, thereby heating the water. The high-pressure liquid refrigerant leaving the secondary-side heat exchanger 13 then passes through the expansion valve 14 to become low-temperature, low-pressure liquid refrigerant and flows into the primary-side heat exchanger 15. The low-temperature, low-pressure liquid refrigerant flowing into the primary-side heat exchanger 15 absorbs heat from the brine flowing through the primary-side circuit C1 in the primary-side heat exchanger 15, where it is evaporated and gasified. Thereafter, the gasified low-pressure gas refrigerant is sucked back into the compressor 11 and circulates through the refrigerant circuit CR.

[0035] In the cooling operation mode, the control device 41 operates the four-way valve 12 to change the refrigerant circulation direction in the refrigerant circuit CR to the opposite direction from that in the heating operation mode. In the cooling operation mode, high-temperature, high-pressure gas refrigerant discharged from the compressor 11 flows through the four-way valve 12 into the primary-side heat exchanger 15. The high-temperature, high-pressure gas refrigerant exchanges heat with brine flowing through the primary-side circuit C1 in the primary-side heat exchanger 15, condensing and liquefying it while releasing heat, becoming a high-pressure liquid refrigerant. The high-pressure liquid refrigerant leaving the primary-side heat exchanger 15 then passes through the expansion valve 14 to become a low-temperature, low-pressure liquid refrigerant and flows into the secondary-side heat exchanger 13. The low-temperature, low-pressure liquid refrigerant that flows into the secondary-side heat exchanger 13 exchanges heat with water flowing through the secondary-side circuit C2 on the load 30 side, evaporating and gasifying it while absorbing heat. The heat released to the water in the secondary-side circuit C2 on the load 30 side is transferred to the refrigerant, thereby cooling the water flowing through the secondary-side circuit C2. Thereafter, the gasified refrigerant is sucked back into the compressor 11 and circulates through the refrigerant circuit CR.

[0036] The ventilation device 10 is disposed inside the indoor unit 2. The ventilation device 10 monitors the presence or absence of refrigerant leakage from the refrigerant circuit CR inside the indoor unit 2, and upon detecting refrigerant leakage, discharges the leaked refrigerant into the external space C. In this way, the ventilation device 10 prevents the refrigerant gas from becoming highly concentrated even in the event of a refrigerant leakage.

[0037] The ventilation device 10 of this embodiment has a protective housing 10 k , a refrigerant sensor 16 , a fan 17 , an exhaust duct 18 , and an intake duct 19 .

[0038] 2 is a perspective view showing each device of the indoor unit 2 housed in the protective housing 10k. The protective housing 10k houses a refrigerant circuit CR, a compressor 11, a four-way valve 12, a secondary heat exchanger 13, an expansion valve 14, a primary heat exchanger 15, a refrigerant sensor 16, a fan 17, an exhaust duct 18, and an intake duct 19.

[0039] The protective housing 10k can substantially seal the interior A of the protective housing 10k. Note that the protective housing 10k may have a small gap. In the event of a refrigerant leak from the refrigerant circuit CR, the protective housing 10k can prevent the refrigerant gas from leaking outside the protective housing 10k into the internal space B of the outer housing 2a. This prevents the refrigerant gas from reaching heat-generating parts and electrically conducting parts even if these parts are present in the internal space B of the outer housing 2a outside the protective housing 10k.

[0040] The protective housing 10k of this embodiment houses the entire refrigerant circuit CR. Therefore, even if a refrigerant leak occurs from any part of the refrigerant circuit CR, the refrigerant gas can be contained within the interior A of the protective housing 10k. However, the protective housing 10k only needs to house at least a part of the refrigerant circuit CR. In this case, the protective housing 10k can contain refrigerant gas that leaks from the part of the refrigerant circuit CR housed within the interior A of the protective housing 10k.

[0041] The protective housing 10k has a bottom plate 10a, a top plate 10b, and side walls 10c. The bottom plate 10a has a bottom surface 10p that covers the interior A of the protective housing 10k from below. The compressor 11, the secondary heat exchanger 13, the primary heat exchanger 15, and the refrigerant sensor 16 are mounted on the bottom surface 10p.

[0042] The top plate 10b has a top surface 10q that covers the interior A of the protective housing 10k from above. The top surface 10q faces the bottom surface 10p in the vertical direction. The sidewalls 10c surround the interior A of the protective housing 10k from the front, back, left, and right.

[0043] 3 is a perspective view of the refrigerant sensor 16 of this embodiment. The refrigerant sensor 16 has a sensor board 16a, a sensor unit 16b, and a wiring unit 16c. The sensor unit 16b is mounted on the sensor board 16a. The sensor unit 16b detects refrigerant gas at a predetermined concentration or higher. The wiring unit 16c extends from the sensor board 16a. The wiring unit 16c is connected to the control device 41. The refrigerant sensor 16 transmits the detection result of the refrigerant gas by the sensor unit 16b to the control device 41 via the wiring unit 16c.

[0044] 4 is a schematic diagram of the ventilation device 10 of this embodiment. The refrigerant sensor 16 of this embodiment is arranged along the bottom surface 10p of the protective housing 10k. As described above, in this embodiment, the density of refrigerant gas is higher than the density of air. Therefore, if refrigerant leaks from the refrigerant circuit CR, the refrigerant gas accumulates in a lower region of the interior A of the protective housing 10k. According to this embodiment, because the refrigerant sensor 16 is arranged along the bottom surface 10p of the protective housing 10k, the refrigerant gas accumulating in the lower region of the interior A can be immediately detected by the refrigerant sensor 16.

[0045] The exhaust duct 18 connects the interior A of the protective housing 10k with an external space C of the indoor unit 2. Here, the external space C of the indoor unit 2 is the space outside the outer housing 2a of the indoor unit 2, and particularly, in this embodiment, is the outdoor space.

[0046] In this embodiment, exhaust duct 18 extends in the vertical direction. Exhaust duct 18 penetrates top plate 10b of protective housing 10k and the top plate of outer housing 2a. The upper end of exhaust duct 18 is located in external space C, and the lower end of exhaust duct 18 is located in interior A of protective housing 10k.

[0047] In the following description, the end of the exhaust duct 18 that is disposed in the interior A of the protective housing 10k and opens into the interior A will be referred to as the exhaust port 18a. In other words, the ventilation device 10 has the exhaust port 18a.

[0048] In this embodiment, the exhaust direction D2 at the exhaust port 18 a is one direction along a horizontal plane. Here, the "exhaust direction D2 at the exhaust port 18 a" refers to the direction in which the exhaust port 18 a draws air from the interior A of the protective housing 10 k and exhausts it into the exhaust duct 18.

[0049] The intake duct 19 connects the interior A of the protective housing 10k with the external space C of the indoor unit 2. In this embodiment, the intake duct 19 extends in the vertical direction. That is, in this embodiment, the exhaust duct 18 and the intake duct 19 extend parallel to each other.

[0050] The intake duct 19 penetrates the top plate 10b of the protective housing 10k and the top plate of the outer housing 2a. The upper end of the intake duct 19 is located in the external space C, and the lower end of the intake duct 19 is located in the interior A of the protective housing 10k.

[0051] In the following description, the end of the intake duct 19 that is disposed in the interior A of the protective housing 10k and opens into the interior A will be referred to as an intake port 19a. In other words, the ventilation device 10 has an intake port 19a.

[0052] In this embodiment, the intake direction D1 of the intake port 19a is downward. Here, the "intake direction D1 of the intake port 19a" refers to the direction in which the intake port 19a draws air from inside the intake duct 19 and blows it out into the interior A of the protective housing 10k.

[0053] In the ventilation device 10 of this embodiment, the exhaust direction D2 at the exhaust port 18a is different from the intake direction D1 at the intake port 19a. If the intake direction D1 and the exhaust direction D2 were the same, there is a risk that gas introduced from the intake port 19a into the interior A of the protective housing 10k would flow into the exhaust port 18a via the shortest path connecting the intake port 19a and the exhaust port 18a. This would make it difficult for air to circulate within the interior A of the protective housing 10k, potentially resulting in a region where refrigerant gas remains within the protective housing 10k and deteriorating ventilation efficiency. Note that, in this specification, the intake direction D1 and the exhaust direction D2 being "different directions" means that the air flow direction at the intake port 19a and the air flow direction at the exhaust port 18a are different from each other. Therefore, the intake direction D1 and the exhaust direction D2 being "different directions" also include the case where the intake direction D1 and the exhaust direction D2 are parallel to each other but in opposite directions.

[0054] According to the present embodiment, the exhaust direction D2 at the exhaust port 18a and the intake direction D1 at the intake port 19a are different from each other, which facilitates air circulation within the interior A of the protective housing 10k. This makes it less likely that a region where the refrigerant gas remains will be created within the interior A of the protective housing 10k, thereby improving the ventilation efficiency of the refrigerant gas.

[0055] In this embodiment, the intake direction D1 and the exhaust direction D2 are perpendicular to each other. Therefore, air introduced from the intake port 19a into the interior A of the protective housing 10k hits the inner surface of the protective housing 10k and then flows toward the exhaust port 18a. According to this embodiment, the air introduced into the interior A of the protective housing 10k promotes air circulation within the interior A of the protective housing 10k. As a result, it is less likely that a region where refrigerant gas remains will be created within the interior A of the protective housing 10k, and the ventilation efficiency of the refrigerant gas can be improved.

[0056] In this embodiment, the intake port 19a faces the bottom surface 10p, which is the inner surface of the protective housing 10k where the refrigerant gas tends to accumulate. Therefore, the air blown from the intake port 19a into the interior A of the protective housing 10k hits the bottom surface 10p where the refrigerant gas accumulates and flows toward the exhaust port 18a while stirring the refrigerant gas. This embodiment makes it less likely that the refrigerant gas will remain in the area along the bottom surface 10p, thereby improving the exhaust efficiency of the refrigerant gas in the interior A of the protective housing 10k.

[0057] In this embodiment, the exhaust port 18 a faces horizontally. This makes it difficult for the exhaust port 18 a to be blocked by the bottom surface 10 p even when the exhaust port 18 a is brought close to the bottom surface 10 p of the protective housing 10 k, making it easier for gas to be drawn into the exhaust port 18 a.

[0058] In this embodiment, the intake port 19a is located above the exhaust port 18a. According to this embodiment, the exhaust port 18a is located in the lower region of the protective housing 10k, making it easier to exhaust the refrigerant that accumulates in the lower region, while the intake port 19a can be located vertically spaced apart from the exhaust port 18a. This allows the air introduced from the intake port 19a into the interior A of the protective housing 10k to be diffused and flow over a wide area of ​​the interior A of the protective housing 10k. This prevents the formation of areas in the interior A of the protective housing 10k where the air flow is stagnant, and prevents refrigerant gas from remaining in the interior A of the protective housing 10k.

[0059] The fan 17 is installed in communication with the exhaust port 18a. The fan 17 generates an airflow in the interior A of the protective housing 10k from the air intake port 19a toward the exhaust port 18a. As a result, the fan 17 generates an airflow that passes from the air intake port 19a through the interior A of the protective housing 10k and is exhausted from the exhaust port 18a. Due to the operation of the fan 17, the air intake port 19a takes in outside air from the external space C into the interior A of the protective housing 10k via the air path of the air intake duct 19. Similarly, due to the operation of the fan 17, the exhaust port 18a exhausts gas from the interior A of the protective housing 10k to the external space C via the air path of the exhaust duct 18.

[0060] In this embodiment, the fan 17 is installed at the exhaust port 18a. Therefore, in this embodiment, the intake port of the fan 17 functions as the exhaust port 18a. This makes it less likely that pressure loss will occur and makes it easier to ensure the gas velocity at the exhaust port 18a compared to when the air path of the exhaust duct 18 extends between the intake port of the fan 17 and the exhaust port 18a.

[0061] In this embodiment, the fan 17 is disposed in a lower region of the interior A of the protective housing 10k. Refrigerant gas leaking from the refrigerant circuit CR accumulates in the lower region of the protective housing 10k. The fan 17 draws in gas containing the refrigerant gas from the lower region of the protective housing 10k and discharges it to the outside via the air passage of the exhaust duct 18.

[0062] The fan 17 may be disposed, for example, inside the exhaust duct 18. That is, the fan 17 may be installed so as to communicate with the exhaust port 18a. Note that "installed so as to communicate with the exhaust port 18a" means that the fan 17 is disposed inside an enclosed space (for example, the exhaust duct 18 in this embodiment) connected to the exhaust port 18a.

[0063] An example of a case where the fan is installed in a location that is not connected to the exhaust port is when the fan is installed midway through an intake duct. In this case, air is sent into the protective housing from the fan intake port. This forces the gas inside the protective housing to be expelled through the exhaust duct that leads to the exhaust port. In this case, multiple devices installed inside the protective housing obstruct the flow of air toward the exhaust port, making it difficult for the air to be exhausted smoothly from the exhaust port. Furthermore, if there are gaps in the protective housing, air is likely to leak through the gaps, which could result in insufficient exhaust from the exhaust port.

[0064] According to this embodiment, by installing the fan 17 in communication with the exhaust port 18a, even when multiple devices are closely arranged inside the protective housing 10k, the gas in the protective housing 10k can be sucked in through the exhaust port 18a, and the inside of the protective housing 10k can be efficiently ventilated.

[0065] The fan 17 is connected to and controlled by a control device 41 (see FIG. 1 ). The control device 41 drives the fan 17 to operate when it receives a detection signal transmitted by the refrigerant sensor 16 along with the refrigerant gas.

[0066] Next, the positional relationship between the exhaust port 18a and the intake port 19a in the protective housing 10k will be described with reference to FIG.

[0067] In this embodiment, the refrigerant gas is heavier than air and therefore tends to accumulate near the bottom surface 10p inside the protective housing 10k. Therefore, in order to efficiently discharge the refrigerant inside the protective housing 10k to the outside, the refrigerant accumulating in the lower part of the protective housing 10k must be carried to the position of the exhaust port 18a by the inertial force of the airflow generated by the fan 17. In the ventilation device 10 of this embodiment, the vertical position of the exhaust port 18a inside the protective housing 10k is determined by focusing on the relationship between the density difference between the air and the refrigerant gas and the wind speed of the fan 17.

[0068] Here, the distance L from the bottom surface 10p of the protective housing 10k to the center CL of the exhaust port 18a is １ and the wind speed U of the gas sucked through the exhaust port 18a. １ When the wind speed U is large or when the wind speed U is small, the inertial force of the airflow generated by the fan 17 is insufficient to counter the downward force (gravity) acting on the refrigerant gas due to the density difference, and the refrigerant gas accumulated near the bottom surface 10p cannot be sufficiently discharged in a short time.

[0069] Here, L １ , g, U, ρ １ , ρ ０ , η are set as follows, it is preferable that the ventilation device 10 of the present embodiment satisfies the following (Equation 1) for each of these parameters.

[0070] L １ [m]: distance from the bottom surface 10p of the protective housing 10k to the center CL of the exhaust port 18a g [m / s ２ ]: Gravitational acceleration 9.8 U [m / s]: Wind speed of gas sucked through exhaust port 18a ρ １ [kg / m ３ ]: Density of refrigerant gas ρ ０ [kg / m３ ]: Density of air η: Constant 3.27

[0071]

[0072] In this embodiment, the exhaust port 18a is provided with a fan 17, and the center CL of the exhaust port 18a is also the center of the intake port of the fan 17. The distance L from the bottom surface 10p of the protective housing 10k to the center CL of the exhaust port 18a is １ is the vertical distance from the bottom surface 10p to the center CL of the exhaust port 18a. The center CL of the exhaust port 18a means the midpoint between the upper end and the lower end of the exhaust port 18a, regardless of the opening direction of the exhaust port 18a. In this embodiment, the density (ρ １ ) is the density of air (ρ ０ ) is higher than (ρ １ >ρ ０ ).

[0073] In the left side of (Equation 1), the numerator correlates to the inertial force of the gas sucked in from the exhaust port 18a by the action of the fan 17. In addition, in the left side of (Equation 1), the denominator correlates to the gravity acting on the refrigerant gas accumulated in the lower part of the protective housing 10k due to the density difference between the refrigerant gas and the air.

[0074] Therefore, the value of the left side of (Equation 1) increases as the inertial force of the refrigerant gas sucked in from the exhaust port 18a by the action of the fan 17 increases. The value of the left side of (Equation 1) also decreases as the force of the refrigerant gas sinking downward due to gravity inside the protective housing 10k increases. (Equation 1) indicates that the refrigerant gas inside the protective housing 10k can be quickly ventilated when the ratio of the numerator to the denominator is greater than the constant shown on the right side.

[0075] Next, a test device and a test method for calculating (Equation 1) will be described. A test device simulating the protective housing 10k (hereinafter simply referred to as the protective housing 10k) was prepared as the test device. The protective housing 10k used as the test housing was a rectangular parallelepiped with a bottom surface 10p measuring 0.70 m in width and 0.60 m in depth and 0.47 m in height.

[0076] The protective housing 10k serving as the test housing is provided with an intake duct 19 and an exhaust duct 18 that each extend linearly in the vertical direction, as in Fig. 4. The intake port 19a of the intake duct 19 faces downward, and the exhaust port 18a of the exhaust duct 18 faces horizontally. A fan 17 is provided at the exhaust port 18a of the exhaust duct 18.

[0077] A refrigerant gas supply pipe was disposed in the protective housing 10k serving as the test housing. The refrigerant gas supply pipe supplied refrigerant gas to the interior A of the protective housing 10k, which was a leakage source of refrigerant gas, instead of the refrigerant circuit CR. Furthermore, a plurality of refrigerant sensors 16 were disposed in the interior A of the protective housing 10k so that the concentration distribution of the refrigerant gas throughout the interior A of the protective housing 10k could be determined.

[0078] In the test, first, refrigerant gas is injected into the protective housing 10k using the refrigerant gas supply pipe, and the supply of refrigerant gas is stopped after the concentration of refrigerant gas in the interior A of the protective housing 10k has increased to a predetermined concentration or higher.

[0079] Next, the fan 17 was operated, thereby discharging the refrigerant gas from the interior A of the protective housing 10k through the exhaust port 18a. Furthermore, the time required from the start of operation of the fan 17 until the refrigerant gas concentrations at all of the refrigerant sensors 16 became equal to or lower than a predetermined concentration was measured.

[0080] In this test, the air volume of the fan 17 was 30 m ３ / h, the fan wind speed U is 4.24 m / s, and the density ρ １ is 1.8 kg / m ３ In this test, the distance L from the bottom surface 10p of the protective housing 10k to the center CL of the exhaust port 18a was １ The experiment was carried out under the first and second conditions, in which the distance L １ In the second condition, the distance L １ was set to 0.141 m.

[0081] 5 is a graph summarizing the test results under the first and second conditions. As shown in FIG. 5, the height of the center CL of the fan 17 (distance L １ It was confirmed that the ventilation time can be shortened by lowering the temperature.

[0082] In this test, if the exhaust time by the ventilation device 10 is 145 seconds or less, sufficient exhaust performance can be obtained for the amount of refrigerant leakage per unit time assumed in the refrigerant circuit CR. In consideration of the fluid dynamic characteristics, the distance L from the bottom surface 10p to the center CL of the exhaust port 18a in the above-mentioned test apparatus is １ By reducing the refrigerant gas, the exhaust time is proportionally shortened. Similarly, the exhaust time is proportional to the gravity (g × (ρ １ -ρ ０ ) / ρ ０ ) and is inversely proportional to the wind speed U of the gas drawn into the exhaust port 18a. Therefore, by setting the left side of (Equation 1) to a specific value (constant η) or more, the exhaust time of the ventilation device 10 can be set to 145 seconds or less. Based on the results of this test, the constant η required to set the exhaust time of the ventilation device 10 to 145 seconds or less was calculated, and the above-mentioned value of 3.27 was calculated.

[0083] In the ventilation device 10 of this embodiment, the distance L from the bottom surface 10p to the center CL of the exhaust port 18a １ is preferably 0.11 m or more. Tests using the above-mentioned test device have confirmed that if the exhaust port 18a is too close to the bottom surface 10p, the gas sucked into the exhaust port 18a at a high flow rate will experience pressure loss due to wall friction with the bottom surface 10p, and the operating point airflow rate of the fan 17 will tend to decrease. As a result of the decrease in airflow rate, the refrigerant gas will tend to stagnate in the corner regions of the protective housing 10k within the interior A of the protective housing 10k. For this reason, in this embodiment, the distance L from the bottom surface 10p to the center CL of the exhaust port 18a is １ By setting the distance L from the bottom surface 10p to the center CL of the exhaust port 18a to 0.11 m or more, the circulation of the refrigerant gas inside the protective housing 10k can be promoted. Furthermore, since the equipment of the indoor unit 2 is mounted on the bottom surface 10p, if the distance L from the center CL of the exhaust port 18a to the bottom surface 10p is lower than 0.11 m, the exhaust port 18a is likely to be blocked by the equipment, and the suction efficiency of the exhaust port 18a may decrease. １By setting the distance to 0.11 m or more, it becomes easier to ensure the suction efficiency at the exhaust port 18a.

[0084] The wind speed U of the gas drawn through the exhaust port 18a can be calculated by dividing the airflow rate generated by the fan 17 by the cross-sectional area of ​​the exhaust port 18a. IEC-60335-2-40 ED7 recommends that the airflow rate of the fan 17 be set to a value exceeding the minimum airflow rate defined by the GG.16 formula, which is determined by the molar mass of the refrigerant used in the refrigerant circuit CR and the amount of refrigerant charged.

[0085] (Summary of First Embodiment) As shown in Fig. 4, the ventilation device 10 of this embodiment includes a protective housing 10k, an intake port 19a, an exhaust port 18a, and a fan 17. The protective housing 10k accommodates at least a part of a refrigerant circuit CR in which a refrigerant circulates. The intake port 19a takes in outside air into the interior A of the protective housing 10k. The exhaust port 18a exhausts gas from the interior of the protective housing 10k. The fan 17 is installed in communication with the exhaust port 18a. The fan 17 generates an air flow that passes from the intake port 19a through the interior A of the protective housing 10k and is exhausted from the exhaust port 18a. The exhaust direction D2 at the exhaust port 18a is different from the intake direction D1 at the intake port 19a. The density of the refrigerant gas obtained by vaporizing the refrigerant is higher than the density of air. Furthermore, the following L １ , g, U, ρ １ , ρ ０ , η satisfy the following relationship (Equation 1): １ [m]: distance from the bottom surface 10p of the protective housing 10k to the center of the exhaust port 18a g [m / s ２ ]: Gravitational acceleration 9.8 U [m / s]: Wind speed of gas sucked through exhaust port 18a ρ １ [kg / m ３ ]: Density of refrigerant gas ρ ０ [kg / m ３ ]: Density of air η: Constant 3.27

[0086]

[0087] This configuration allows the intake performance of the fan 17 and the position of the exhaust port 18a to be determined based on the density of the refrigerant gas. This eliminates the need for excessive airflow performance in the fan 17, thereby reducing the cost of the ventilation device 10. Furthermore, the flexibility in the placement of the exhaust port 18a is increased, enabling efficient ventilation without placing the exhaust port 18a excessively close to the bottom surface 10p of the protective housing 10k. In particular, multiple devices housed in the protective housing 10k are mounted on the bottom surface 10p of the protective housing 10k. The above configuration ensures that the wind speed U and the placement of the exhaust port 18a satisfy Equation 1, thereby enabling efficient placement of multiple devices within the interior A of the protective housing 10k and reducing the size of the protective housing 10k. Furthermore, this configuration allows the fan 17 to be installed in communication with the exhaust port 18a. That is, the fan 17 is installed in an enclosed space, such as the exhaust duct 18, where the exhaust port 18a opens (the exhaust duct 18 in this embodiment). Therefore, the air blown by the fan 17 can efficiently draw gas from the interior A of the protective housing 10k through the exhaust port 18a. In addition, with this configuration, the exhaust direction D2 and the intake direction D1 are different from each other, which facilitates the circulation of air within the interior A of the protective housing 10k. This makes it less likely that a region where refrigerant gas remains will be created within the interior A of the protective housing 10k. As a result, it becomes easier to exhaust refrigerant gas from every corner of the interior A of the protective housing 10k.

[0088] In the ventilation device 10 of this embodiment, the distance L from the bottom surface 10p of the protective housing 10k to the center of the exhaust port 18a １ is preferably 0.11 m or more. With this configuration, pressure loss due to wall friction between the bottom surface 10p and the gas sucked into the exhaust port 18a at a high flow rate can be suppressed, and a decrease in the operating point air volume of the fan 17 can be avoided. That is, the air sucked from the inside A of the protective housing 10k through the exhaust port 18a can promote the circulation of air within the inside A of the protective housing 10k, making it easier to exhaust the refrigerant gas from every corner of the inside A of the protective housing 10k. Furthermore, the distance L from the bottom surface 10p to the center CL of the exhaust port 18a １By setting the clearance to 0.11 m or more, the exhaust port 18a is less likely to be blocked by the bottom surface 10p and the devices mounted on the bottom surface 10p. This makes it easier to ensure the suction efficiency at the exhaust port 18a.

[0089] In the ventilation device 10 of this embodiment, the intake direction D1 and the exhaust direction D2 are perpendicular to each other. With this configuration, air introduced from the intake port 19a into the interior A of the protective housing 10k hits the inner surface of the protective housing 10k and then flows toward the exhaust port 18a. Therefore, the air introduced into the interior A of the protective housing 10k can promote circulation of air within the interior A of the protective housing 10k, making it easier to exhaust the refrigerant gas from every corner of the interior A of the protective housing 10k.

[0090] In the ventilation device 10 of this embodiment, the fan 17 is disposed at the exhaust port 18a. With this configuration, the intake port of the fan 17 functions as the exhaust port 18a. This makes it easier to ensure the wind speed of the gas drawn into the exhaust port 18a, and shortens the time required to ventilate the interior A of the protective housing 10k.

[0091] As shown in Fig. 1, the indoor unit 2 of this embodiment includes the above-described ventilation device 10, at least a portion of the refrigerant circuit CR, and a secondary-side heat exchanger (heat medium heat exchanger) 13. The secondary-side heat exchanger 13 is disposed inside the protective housing 10k. The secondary-side heat exchanger 13 exchanges heat between the refrigerant and a heat medium different from the refrigerant (water in the first embodiment). With this configuration, the indoor unit 2 can transfer heat or cold from the refrigerant circuit CR to the heat medium via the secondary-side heat exchanger 13 and utilize the heat or cold.

[0092] The indoor unit 2 of this embodiment includes a secondary-side circuit (heat medium circuit) C2. The secondary-side circuit C2 supplies the heat medium that has exchanged heat with the refrigerant in the secondary-side heat exchanger 13 to the cooling and heating device 30a. With this configuration, the heat or cold of the refrigerant circuit CR can be used for heating and cooling operation of the cooling and heating device 30a via the secondary-side circuit C2.

[0093] The indoor unit 2 of this embodiment includes a water storage tank 30b and a secondary-side circuit (heat medium circuit) C2. The water storage tank 30b stores water. The secondary-side circuit C2 heats or cools the water stored in the water storage tank 30b using the heat medium that has exchanged heat with the refrigerant in the secondary-side heat exchanger 13. With this configuration, heat or cold from the refrigerant circuit CR can be transferred via the secondary-side circuit C2 to the water stored in the water storage tank 30b and used as needed.

[0094] (Embodiment 2) Fig. 6 is a schematic diagram of a ventilation device 110 according to embodiment 2. Note that components that are the same as those in the above-described embodiment are given the same reference numerals, and descriptions thereof will be omitted.

[0095] Similar to the above-described embodiment, the ventilation device 110 of this embodiment comprises a protective housing 10k, an intake duct 19 having an intake port 19a, an exhaust duct 18 having an exhaust port 118a, a fan 17, and a refrigerant sensor 116.

[0096] As in the above-described embodiment, the protective housing 10k accommodates at least a portion of the refrigerant circuit CR. A refrigerant flows through the refrigerant circuit CR. In this embodiment, the density of the refrigerant gas obtained by vaporizing the refrigerant is lower than the density of air. Therefore, the refrigerant gas is lighter than air and accumulates near the top surface 10q in the interior A of the protective housing 10k. An example of such a refrigerant is ammonia.

[0097] In this embodiment, the refrigerant sensor 116 is disposed along the top surface 10q of the protective housing 10k, so that the refrigerant sensor 116 can immediately detect the refrigerant gas that accumulates in the lower region of the interior A of the protective housing 10k.

[0098] In this embodiment, the intake port 19a is located below the exhaust port 118a. According to this embodiment, when the exhaust port 118a is located in the upper region of the protective housing 10k to facilitate the discharge of refrigerant gas near the top surface 10q, the intake port 19a and the exhaust port 118a can be spaced apart in the vertical direction. This ensures a distance between the intake port 19a and the exhaust port 118a, allowing air to diffuse over a wide area within the interior A of the protective housing 10k along the air path from the intake port 19a to the exhaust port 118a. As a result, it is possible to prevent the formation of a region where refrigerant gas remains within the interior A of the protective housing 10k.

[0099] In this embodiment, the intake direction D1 and the exhaust direction D2 are perpendicular to each other. Therefore, air introduced from the intake port 19a into the interior A of the protective housing 10k hits the inner surface of the protective housing 10k and then flows toward the exhaust port 118a. Therefore, the air introduced into the interior A of the protective housing 10k can promote the circulation of air within the interior A of the protective housing 10k. As a result, it is less likely that a region where refrigerant gas remains will be created within the interior A of the protective housing 10k, and the ventilation efficiency of the refrigerant gas can be improved.

[0100] The distance L from the top surface 10q of the protective housing 10k to the center CL of the exhaust port 118a ２ and the wind speed U of the gas sucked through the exhaust port 118a. ２ When the airflow velocity U is large or when the airflow velocity U is small, the inertial force of the airflow generated by the fan 17 is insufficient to counter the upward force (buoyancy) acting on the refrigerant gas due to the density difference, and the refrigerant gas accumulated near the top surface 10q cannot be quickly discharged. In the ventilation device 110 according to this embodiment, the vertical position of the exhaust port 118a is determined by taking into account the relationship between the inertial force of the airflow and the buoyancy acting on the refrigerant gas.

[0101] Here, L ２ , g, U, ρ １ , ρ ０ , η are set as follows, it is preferable that the ventilation device 110 of this embodiment satisfies the following (Equation 2) for each of these parameters.

[0102] g [m / s ２]: Gravitational acceleration 9.8 U [m / s]: Wind speed of gas sucked through exhaust port 118a L ２ [m]: distance ρ from the top surface 10q of the protective housing 10k to the center CL of the exhaust port 118a １ [kg / m ３ ]: Density of refrigerant gas ρ ０ [kg / m ３ ]: Air density

[0103]

[0104] In this embodiment, the exhaust port 118a is provided with a fan 17, and the center CL of the exhaust port 118a is the center of the intake port of the fan 17. The distance L from the top surface 10q of the protective housing 10k to the center CL of the exhaust port 118a is １ is the vertical distance from the top surface 10q to the center CL of the exhaust port 118a. The center CL of the exhaust port 118a means the midpoint between the upper end and the lower end of the exhaust port 118a, regardless of the opening direction of the exhaust port 118a. In this embodiment, the density (ρ １ ) is the density of air (ρ ０ ) is lower than (ρ １ <ρ ０ ).

[0105] Equation 2 is an equation derived based on the calculation test in the above-described embodiment 1. Equation 2 indicates that when the ratio of the numerator to the denominator is greater than the constant shown on the right side, the refrigerant gas in the interior A of the protective housing 10k can be ventilated quickly.

[0106] In the ventilation device 110 of this embodiment, the distance L from the top surface 10q to the center CL of the exhaust port 118a ２ It is preferable that the distance be 0.11 m or more. This makes it possible to suppress pressure loss caused by wall friction between the top surface 10q and the gas sucked into the exhaust port 118a at a high flow rate, and to avoid a decrease in the operating point airflow rate of the fan 17.

[0107] (Summary of Second Embodiment) The ventilation device 110 of this embodiment includes a protective housing 10k, an intake port 19a, an exhaust port 118a, and a fan 17. The protective housing 10k accommodates at least a part of a refrigerant circuit CR in which a refrigerant circulates. The intake port 19a takes in outside air into the interior A of the protective housing 10k. The exhaust port 118a exhausts gas from the interior of the protective housing 10k. The fan 17 is installed in communication with the exhaust port 118a. The fan 17 generates an air flow that passes from the intake port 19a through the interior A of the protective housing 10k and is exhausted from the exhaust port 118a. The exhaust direction D2 at the exhaust port 118a is different from the intake direction D1 at the intake port 19a. The density of the refrigerant gas obtained by vaporizing the refrigerant is lower than the density of air. Furthermore, the following L ２ , g, U, ρ １ , ρ ０ , η satisfy the following relationship (Equation 2): ２ [m]: distance from the top surface 10q of the protective housing 10k to the center CL of the exhaust port 118a g [m / s ２ ]: Gravitational acceleration 9.8 U [m / s]: Wind speed of gas sucked through exhaust port 118a ρ １ [kg / m ３ ]: Density of refrigerant gas ρ ０ [kg / m ３ ]: Density of air η: Constant 3.27

[0108]

[0109] This configuration allows the intake performance of the fan 17 and the position of the exhaust port 118a to be determined based on the density of the refrigerant gas. This eliminates the need for excessive airflow performance in the fan 17, allowing for a more cost-effective ventilator 110. Furthermore, this configuration increases the flexibility of the exhaust port 118a's location, eliminating the need to position the exhaust port 118a excessively close to the bottom surface 10p of the protective housing 10k, enabling efficient ventilation. Furthermore, this configuration allows the fan 17 to be installed in communication with the exhaust port 118a, allowing the fan 17 to efficiently draw gas from the interior A of the protective housing 10k through the exhaust port 118a. Furthermore, this configuration, because the exhaust direction D2 and the intake direction D1 are different directions, reduces the likelihood of refrigerant gas remaining in the interior A of the protective housing 10k, making it easier to expel the refrigerant gas from the interior A of the protective housing 10k.

[0110] With this configuration, the distance from the top surface 10q of the protective housing 10k to the center CL of the exhaust port 118a is 0.11 m or more. With this configuration, the air drawn from the interior A of the protective housing 10k through the exhaust port 118a can promote the circulation of the refrigerant gas within the interior A of the protective housing 10k.

[0111] (Embodiment 3) Figure 7 is a schematic diagram showing the configuration of an air conditioner 201 according to Embodiment 3. The air conditioner 201 of this embodiment differs from the geothermal heat pump system 1 of Embodiment 1 described above mainly in terms of the heat extraction means. That is, the air conditioner 201 of this embodiment does not use geothermal energy as in the above-described embodiments, but instead heats and cools the refrigerant using an outdoor heat exchanger 71 that exchanges heat between outdoor air and the refrigerant. Note that components that are the same as those in the above-described embodiments are designated by the same reference numerals, and their description will be omitted.

[0112] The air conditioner 201 of this embodiment includes an indoor unit 202, an outdoor unit 203, a heat pump unit 220A, a secondary side circuit C2, a load 30, a remote controller 42, and a control device 41. The indoor unit 202 is located indoors, and the outdoor unit 203 is located outdoors. The heat pump unit 220A is located between the indoor unit 202 and the outdoor unit 203. The indoor unit 202 is also provided with a ventilation device 10. The ventilation device 10 exhausts refrigerant gas leaking from the refrigerant circuit CR of the heat pump unit 220A to the exterior space C.

[0113] The heat pump unit 220A includes a secondary heat exchanger 13 disposed in the indoor unit 202, a four-way valve 12, a compressor 11, an outdoor heat exchanger 71, and an expansion valve 14 disposed in the outdoor unit 203, and refrigerant piping that connects these components to form a refrigerant circuit CR. In this embodiment, the outdoor heat exchanger 71 exchanges heat between the refrigerant in the refrigerant circuit CR and outside air. Although not shown, the outdoor unit 203 may be provided with a blower fan that blows air toward the outdoor heat exchanger 71 to promote heat exchange between the outside air and the refrigerant.

[0114] In the heating operation mode, the high-temperature, high-pressure gas refrigerant discharged from the compressor 11 flows through the four-way valve 12 into the secondary-side heat exchanger 13. The high-temperature, high-pressure gas refrigerant exchanges heat with water flowing through the secondary-side circuit C2 in the secondary-side heat exchanger 13, condensing and liquefying while releasing heat, becoming high-pressure liquid refrigerant. The heat released from the refrigerant is imparted to water flowing through the secondary-side circuit C2 on the load 30 side, thereby warming the water. The high-pressure liquid refrigerant that leaves the secondary-side heat exchanger 13 then passes through the expansion valve 14 to become low-temperature, low-pressure liquid refrigerant, and flows into the outdoor heat exchanger 71 of the outdoor unit 203. The low-temperature, low-pressure liquid refrigerant that flows into the outdoor heat exchanger 71 absorbs heat from the outside air in the outdoor heat exchanger 71, evaporates, and gasifies. The gasified low-pressure gas refrigerant is then drawn back into the compressor 11 and circulates through the refrigerant circuit CR.

[0115] In the cooling operation mode, high-temperature, high-pressure gas refrigerant discharged from the compressor 11 flows through the four-way valve 12 into the outdoor heat exchanger 71. The high-temperature, high-pressure gas refrigerant exchanges heat with outside air in the outdoor heat exchanger 71, condensing and liquefying while releasing heat, becoming a high-pressure liquid refrigerant. The high-pressure liquid refrigerant leaving the outdoor heat exchanger 71 then passes through the expansion valve 14 to become a low-temperature, low-pressure liquid refrigerant and flows into the secondary-side heat exchanger 13. The low-temperature, low-pressure liquid refrigerant that flows into the secondary-side heat exchanger 13 exchanges heat with water flowing through the secondary-side circuit C2 on the load 30 side, evaporating and gasifying while absorbing heat. The heat released to the water in the secondary-side circuit C2 on the load 30 side is transferred to the refrigerant, thereby cooling the water flowing through the secondary-side circuit C2. The gasified refrigerant is then drawn back into the compressor 11 and circulates through the refrigerant circuit CR.

[0116] (Summary of Embodiment 3) The air conditioner 201 of this embodiment includes an indoor unit 202 and an outdoor unit 203. The outdoor unit 203 has at least a portion of a refrigerant circuit CR and an outdoor heat exchanger 71 that exchanges heat between the refrigerant and outdoor air. Similarly to the above-described embodiments, the indoor unit 202 also includes a ventilation device 10 similar to the above-described embodiments, at least a portion of the refrigerant circuit CR, a secondary-side heat exchanger 13, a water storage tank 30b, and a secondary-side circuit C2. The secondary-side heat exchanger 13 is disposed inside the protective housing 10k and exchanges heat between the refrigerant and water (heat medium). The water storage tank 30b stores water. The secondary-side circuit C2 heats or cools the water stored in the water storage tank using the water that has exchanged heat with the refrigerant by the secondary-side heat exchanger 13.

[0117] According to this configuration, since the air conditioner 201 has an outdoor unit 203, it is possible to cool or heat the refrigerant with outdoor air, and the heat or cold of the outdoor air can be used to operate the air conditioning and heating device 30a or to heat or cool water stored in the water storage tank 30b. Furthermore, according to this configuration, the portion of the refrigerant circuit CR located in the indoor unit 202 is protected by the ventilation device 10. Therefore, if a refrigerant leak occurs inside the indoor unit 202, the refrigerant gas can be exhausted to the outside into the external space C. On the other hand, if a refrigerant leak occurs inside the outdoor unit 203, the refrigerant gas is naturally discharged from inside the outdoor unit 203 to the external space C.

[0118] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the configurations of the above-described embodiments, and the following configurations and methods may also be employed. Furthermore, the configurations and methods described in this specification may be combined as appropriate within the scope of not being mutually inconsistent.

[0119] For example, in the above-described embodiments, the exhaust duct and the intake duct have been described as extending uniformly in the vertical direction. However, the exhaust duct and the intake duct may be curved or may extend uniformly in the horizontal direction, for example. Furthermore, in the above-described embodiments, the exhaust port is located at the lower end of the exhaust duct and the intake port is located at the lower end of the intake duct. However, in cases where the exhaust duct or the intake duct extends upward from the floor surface, the exhaust port and the intake port may be located at the upper end of the exhaust duct and the intake duct, respectively.

[0120] 2, 202... Indoor unit, 10, 110... Ventilation device, 10k... Protective housing, 10p... Bottom surface, 10q... Top surface, 13... Secondary side heat exchanger (heat medium heat exchanger), 17... Fan, 18a, 118a... Exhaust port, 19a... Intake port, 30a... Heating and cooling device, 30b... Water tank, 71... Outdoor heat exchanger, 201... Air conditioner, 203... Outdoor unit, A... Interior, C2... Secondary side circuit (heat medium circuit), CL... Center, CR... Refrigerant circuit, D1... Intake direction, D2... Exhaust direction, L1, L2... Distance, U... Wind speed, η... Constant, ρ1... Density

Claims

1. A device comprising: a protective housing that houses at least a part of a refrigerant circuit in which a refrigerant circulates; an intake port that takes in outside air into the protective housing; an exhaust port that exhausts gas from the inside of the protective housing; and a fan that generates an air flow that passes from the intake port through the inside of the protective housing and is exhausted from the exhaust port, wherein the exhaust direction at the exhaust port is different from the intake direction at the intake port; the density of the refrigerant gas vaporized from the refrigerant is higher than the density of air; and １ , g, U, ρ １ , ρ ０ , η satisfies the following relationship (Equation 1). １ [m]: Distance from the bottom surface of the protective housing to the center of the exhaust port g [m / s ２ ]: Gravitational acceleration 9.8 U [m / s]: Wind speed of gas sucked through the exhaust port ρ １ [kg / m ３ ]: density ρ of the refrigerant gas ０ [kg / m ３ ]: Density of air η: Constant 3.27 2. A device comprising: a protective housing that houses at least a part of a refrigerant circuit in which a refrigerant circulates; an intake port that takes in outside air into the protective housing; an exhaust port that exhausts gas from the inside of the protective housing; and a fan that generates an air flow that passes from the intake port through the inside of the protective housing and is exhausted from the exhaust port, wherein the exhaust direction at the exhaust port is different from the intake direction at the intake port; the density of the refrigerant gas vaporized from the refrigerant is lower than the density of air; and ２ , g, U, ρ １ , ρ ０ , η satisfies the following relationship (Equation 2). ２ [m]: Distance from the top surface of the protective housing to the center of the exhaust port g [m / s ２ ]: Gravitational acceleration 9.8 U [m / s]: Wind speed of gas sucked through the exhaust port ρ １ [kg / m ３ ]: density ρ of the refrigerant gas ０ [kg / m ３ ]: Density of air η: Constant 3.27 3. The ventilation device according to claim 1 or 2, wherein the intake direction and the exhaust direction are perpendicular to each other.

4. The ventilation device according to any one of claims 1 to 3, wherein the fan is disposed at the exhaust port.

5. An indoor unit comprising: the ventilation device according to any one of claims 1 to 4; at least a part of the refrigerant circuit; and a heat medium heat exchanger that is disposed inside the protective housing and exchanges heat between the refrigerant and a heat medium different from the refrigerant.

6. The indoor unit according to claim 5, further comprising a heat medium circuit that supplies the heat medium that has exchanged heat with the refrigerant in the heat medium heat exchanger to a heating and cooling device.

7. The indoor unit according to claim 5, comprising: a water storage tank for storing water; and a heat medium circuit for heating or cooling the water stored in the water storage tank by the heat medium that has exchanged heat with the refrigerant in the heat medium heat exchanger.

8. An air conditioner comprising: an indoor unit according to claim 6 or 7; and an outdoor unit having an outdoor heat exchanger that exchanges heat between at least a part of the refrigerant circuit and the refrigerant and outside air.

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