Ventilation systems, indoor units, and air conditioners

Abstract

One embodiment of the ventilation device according to the present disclosure comprises a protective housing that encloses at least a portion of a refrigerant circuit through which a refrigerant circulates, an intake port for taking in outside air into the protective housing, an exhaust port for discharging gas from the inside of the protective housing, and a fan that generates an airflow 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 arrangement of the exhaust port is optimized according to the wind velocity U of the gas drawn in from the exhaust port and the density ρ1 of the refrigerant gas.

Description

[Technical Field]

[0001] This disclosure relates to ventilation systems, indoor units, and air conditioners. [Background technology]

[0002] Conventionally, in heat source units that use flammable refrigerants, a fan is provided to ventilate the inside of the electrical component box to prevent the accumulation of refrigerant gas inside the box (for example, Patent Document 1). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2016-191505 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Generally, because the density of refrigerant gas differs from that of air, it can accumulate in the upper or lower parts of the enclosure, leading to localized increases in concentration. Depending on the placement of fans within the enclosure, this can result in inefficient ventilation due to the concentration variations caused by the difference in density between air and refrigerant gas, leading to prolonged ventilation.

[0005] In view of the circumstances described above, one of the purposes of this disclosure is to provide a ventilation device that can improve the ventilation efficiency inside the enclosure, as well as an indoor unit and an air conditioner having such a ventilation device. [Means for solving the problem]

[0006] One embodiment of a ventilation device according to the present disclosure comprises a protective housing that houses at least a portion of a refrigerant circuit through which a refrigerant circulates, an intake port for taking in outside air into the protective housing, an exhaust port for discharging gas from the inside of the protective housing, and a fan that generates an airflow 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 vaporized refrigerant gas is higher than the density of air, and the following L1, g, U, ρ1, ρ0, η satisfy the relationship (Equation 1) below. L1[m]: Distance from the bottom surface of the protective housing to the center of the exhaust port g[m / s 2 ]:Gravity acceleration 9.8 U[m / s]: Wind speed of the gas drawn in from the exhaust port. ρ1[kg / m 3 ]: Density of the refrigerant gas ρ0[kg / m 3 ]: air density η: constant 3.27

number

[0007] One embodiment of a ventilation device according to the present disclosure comprises a protective housing that houses at least a portion of a refrigerant circuit through which a refrigerant circulates, an intake port for taking in outside air into the protective housing, an exhaust port for discharging gas from the inside of the protective housing, and a fan that generates an airflow 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 vaporized refrigerant gas is lower than the density of air, and the following L2, g, U, ρ1, ρ0, η satisfy the relationship shown in (Equation 2). L2[m]: Distance from the top surface of the protective housing to the center of the exhaust port g[m / s 2 ]:Gravity acceleration 9.8 U[m / s]: Wind speed of the gas drawn in from the exhaust port. ρ1[kg / m 3: Density of the refrigerant gas ρ0 [kg / m 3 : Density of air η: Constant 3.27

Number

[0008] One aspect of the 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 disposed inside the protection housing that exchanges heat between the refrigerant and a heat medium different from the refrigerant.

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

Advantages of the Invention

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

Brief Description of the Drawings

[0011] [Figure 1] Schematic diagram schematically showing the configuration of the ground source heat pump system according to Embodiment 1. [Figure 2] Perspective view showing each device of the indoor unit housed in the protection housing according to Embodiment 1. [Figure 3] Perspective view of the refrigerant sensor according to Embodiment 1. [Figure 4] Schematic diagram of the ventilation device according to Embodiment 1. [Figure 5] Graph summarizing the test results. [Figure 6] Schematic diagram of the ventilation device according to Embodiment 2. [Figure 7] Schematic diagram schematically showing the configuration of the air conditioner according to Embodiment 3.

Modes for Carrying Out the Invention

[0012] (Embodiment 1) Figure 1 is a schematic diagram illustrating the configuration of the geothermal heat pump system 1 according to Embodiment 1.

[0013] The geothermal heat pump system 1 is connected to a ground source heat exchanger 23 buried underground and a load 30 installed indoors. The geothermal heat pump system 1 uses a heat pump to extract heat from the ground via a primary circuit C1 having the ground source heat exchanger 23 and supplies it 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 uses geothermal energy to adjust the temperature of the air in the living space.

[0015] In this embodiment, brine circulates in the primary circuit C1, and water circulates in the secondary circuit (heat transfer medium circuit) C2. The heat transfer medium flowing through the primary circuit C1 and the heat transfer medium flowing through the secondary circuit C2 can be any liquid fluid.

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

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

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

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

[0020] Brine from the primary circuit C1 flows into the primary heat exchanger 15. The primary heat exchanger 15 performs heat exchange between the brine and the refrigerant from the refrigerant circuit CR. Water (heat transfer medium) from the secondary heat exchanger 13 flows into the secondary heat exchanger 13. The secondary heat exchanger 13 performs heat exchange between the water from the secondary circuit C2 and the refrigerant from the refrigerant circuit CR. The compressor 11 circulates the refrigerant in the refrigerant circuit CR. The expansion valve 14 reduces the pressure of the refrigerant. The expansion valve 14 in this embodiment is an electronically controlled expansion valve whose opening degree is variably controlled. The four-way valve 12 is located in the part 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 part of the path in the refrigerant circuit CR.

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

[0022] A refrigerant circuit CR circulates, for example, a flammable refrigerant. The concept of flammability as used herein includes mildly flammable substances. The refrigerant vaporizes at atmospheric pressure. In the following description, the refrigerant vaporized at atmospheric pressure is referred to as the refrigerant gas. The density of the refrigerant gas is higher than that of air. That is, the refrigerant gas is heavier than air and accumulates below the air in a space filled with air.

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

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

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

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

[0027] The secondary pump 31 circulates water in the refrigerant circuit CR. The electric heater 33 further heats the hot water 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 sensor 32 measures the flow rate of water circulating in the refrigerant circuit CR. The primary circuit C1 may also be provided with a temperature sensor to measure the temperature of the water flowing into the secondary heat exchanger 13 (inflow temperature) and a temperature sensor to measure the temperature of the generated hot water (return temperature).

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

[0029] The load 30 in this embodiment includes a water storage tank 30b that supplies hot water to a bath, etc., and a heating and cooling device 30a. The water stored in the water storage tank 30b exchanges heat with the water (hot water or cooling water) flowing through the secondary circuit C2. As a result, the water in the water storage tank 30b is heated or cooled. The water storage tank 30b can also make the stored water available for use in a bath, etc., as needed. The heating and cooling device 30a uses the water (hot water or cooling water) flowing through the secondary circuit C2 to provide heating and cooling in the living space.

[0030] The secondary circuit C2 branches at the flow path switching device 34 located downstream of the secondary heat exchanger 13 and the electric heater 33. The branched piping extends to the water storage tank 30b and the heating and cooling system 30a, respectively. The piping returning from the water storage tank 30b and the heating and cooling system 30a then rejoins. In other words, the flow path switching device 34 switches the destination of the hot water circulation between the water storage tank 30b and the heating and cooling system 30a.

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

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

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

[0034] In heating and hot water supply operation mode, the control device 41 operates the four-way valve 12 to control the circulation direction of the refrigerant in the refrigerant circuit CR. In heating operation mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 11 flows into the secondary heat exchanger 13 through the four-way valve 12. The high-temperature, high-pressure gaseous refrigerant condenses and liquefies while releasing heat by exchanging heat with the water flowing in the secondary circuit C2 in the secondary heat exchanger 13, becoming a high-pressure liquid refrigerant. In addition, the heat released from the refrigerant is transferred to the water flowing in the secondary circuit C2 on the load 30 side, warming the water. The high-pressure liquid refrigerant that leaves the secondary heat exchanger 13 then passes through the expansion valve 14 to become a low-temperature, low-pressure liquid refrigerant and flows into the primary heat exchanger 15. The low-temperature, low-pressure liquid refrigerant that flows into the primary heat exchanger 15 absorbs heat from the brine flowing in the primary circuit C1 in the primary heat exchanger 15, evaporates, and gasifies. Subsequently, the gasified low-pressure gaseous refrigerant is drawn back into the compressor 11 and circulates through the refrigerant circuit CR.

[0035] In cooling operation mode, the control device 41 operates the four-way valve 12 to reverse the direction of refrigerant circulation in the refrigerant circuit CR compared to heating operation mode. In cooling operation mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 11 flows into the primary heat exchanger 15 through the four-way valve 12. The high-temperature, high-pressure gaseous refrigerant condenses and liquefies while releasing heat by exchanging heat with the brine flowing through the primary circuit C1 in the primary heat exchanger 15, becoming a high-pressure liquid refrigerant. The high-pressure liquid refrigerant that leaves the primary heat exchanger 15 then passes through the expansion valve 14 to become a low-temperature, low-pressure liquid refrigerant, which flows into the secondary heat exchanger 13. The low-temperature, low-pressure liquid refrigerant that flows into the secondary heat exchanger 13 exchanges heat with the water flowing through the secondary circuit C2, which is on the load 30 side, absorbing heat as it evaporates and gasifies, and the heat released to the water in the secondary circuit C2 on the load 30 side is transferred to the refrigerant, cooling the water flowing through the secondary circuit C2. The gasified refrigerant is then drawn back into the compressor 11 and circulates through the refrigerant circuit CR.

[0036] The ventilation device 10 is located inside the indoor unit 2. Inside the indoor unit 2, the ventilation device 10 monitors for refrigerant leakage from the refrigerant circuit CR and, when it detects a refrigerant leak, discharges the leaked refrigerant to the outside space C. In this way, the ventilation device 10 suppresses the development of high concentrations of refrigerant gas even if a refrigerant leak occurs.

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

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

[0039] The protective enclosure 10k can generally seal the interior A of the protective enclosure 10k. However, the protective enclosure 10k may have small gaps. The protective enclosure 10k can prevent refrigerant gas from leaking out of the protective enclosure 10k into the internal space B of the outer enclosure 2a when refrigerant leakage occurs from the refrigerant circuit CR. This prevents refrigerant gas from reaching heat-generating parts and energized parts even if they are located outside the protective enclosure 10k in the internal space B of the outer enclosure 2a.

[0040] In this embodiment, the protective housing 10k encloses the entire refrigerant circuit CR. Therefore, even if refrigerant leakage 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 enclose at least a portion of the refrigerant circuit CR. In this case, the protective housing 10k can contain refrigerant gas leaking from the portion of the refrigerant circuit CR contained within the interior A of the protective housing 10k.

[0041] The protective housing 10k has a bottom plate portion 10a, a top plate portion 10b, and side wall portions 10c. The bottom plate portion 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 portion 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 side wall portions 10c surround the interior A of the protective housing 10k from the front, back, left, and right.

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

[0044] Figure 4 is a schematic diagram of the ventilation device 10 of this embodiment. In this embodiment, the refrigerant sensor 16 is positioned along the bottom surface 10p of the protective housing 10k. As described above, in this embodiment, the density of the refrigerant gas is higher than the density of air. Therefore, if refrigerant leaks from the refrigerant circuit CR, the refrigerant gas accumulates in the lower region of the interior A of the protective housing 10k. According to this embodiment, since the refrigerant sensor 16 is positioned 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 to the exterior space C of the indoor unit 2. Here, the exterior space C of the indoor unit 2 is the space outside the outer housing 2a of the indoor unit 2, and in this embodiment in particular, it is the outdoor space.

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

[0047] In the following description, the end of the exhaust duct 18 that is located inside the protective housing 10k (A) and opens into A will be referred to as the exhaust port 18a. That is, the ventilation device 10 has an exhaust port 18a.

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

[0049] The intake duct 19 connects the interior A of the protective housing 10k to the exterior 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 portion 10b of the protective housing 10k and the top plate portion 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 inside A of the protective housing 10k.

[0051] In the following description, the end of the intake duct 19 that is located inside the protective housing 10k (A) and opens into A will be referred to as the intake port 19a. That is, the ventilation device 10 has an intake port 19a.

[0052] In this embodiment, the intake direction D1 at the intake port 19a is downward. Here, "intake direction D1 at the intake port 19a" refers to the direction in which the intake port 19a draws in 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 are in the same direction, there is a risk that the gas introduced from the intake port 19a into the interior A of the protective housing 10k will flow into the exhaust port 18a by taking the shortest distance between the intake port 19a and the exhaust port 18a. As a result, air circulation will be less likely to occur inside the interior A of the protective housing 10k, and consequently, a residual area of ​​refrigerant gas may be created inside the protective housing 10k, potentially worsening ventilation efficiency. In this specification, "different directions" for the intake direction D1 and the exhaust direction D2 means that the direction of airflow at the intake port 19a and the direction of airflow at the exhaust port 18a are different from each other. Therefore, the statement that the intake direction D1 and the exhaust direction D2 are "in different directions" includes the case where the intake direction D1 and the exhaust direction D2 are parallel to each other and oriented in opposite directions.

[0054] According to this embodiment, the exhaust direction D2 at the exhaust port 18a and the intake direction D1 at the intake port 19a are in different directions, which makes it easier to circulate air inside the protective housing 10k A. As a result, it is less likely that a residual area of ​​refrigerant gas will form inside the protective housing 10k A, and the ventilation efficiency of the refrigerant gas can be improved.

[0055] In this embodiment, the intake direction D1 and the exhaust direction D2 are orthogonal to each other. Therefore, the air introduced from the intake port 19a into the interior A of the protective housing 10k strikes the inner surface of the protective housing 10k before heading towards 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 becomes less likely for residual refrigerant gas to form in 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 an inner surface of the protective housing 10k where refrigerant gas tends to accumulate. Therefore, the air blown from the intake port 19a into the interior A of the protective housing 10k flows towards the exhaust port 18a while agitating the refrigerant gas as it hits the bottom surface 10p where the refrigerant gas accumulates. According to this embodiment, it is less likely that a residual area of ​​refrigerant gas will form in the region along the bottom surface 10p, and the exhaust efficiency of the refrigerant gas from the interior A of the protective housing 10k can be improved.

[0057] In this embodiment, the exhaust port 18a faces horizontally. This makes it less likely for the exhaust port 18a to be blocked by the bottom surface 10p of the protective housing 10k, and makes it easier for gas to be drawn into the exhaust port 18a.

[0058] In this embodiment, the intake port 19a is located above the exhaust port 18a. According to this embodiment, the exhaust port 18a is positioned in the lower region of the protective housing 10k to facilitate the exhaust of refrigerant accumulated in the lower region, while the intake port 19a can be positioned vertically separated from the exhaust port 18a. As a result, the air guided from the intake port 19a into the interior A of the protective housing 10k can be diffused and flowed over a wide area of ​​the interior A of the protective housing 10k. This suppresses the formation of areas where airflow stagnates in the interior A of the protective housing 10k, and suppresses the residue of refrigerant gas in the interior A of the protective housing 10k.

[0059] Fan 17 is installed in communication with exhaust port 18a. Fan 17 forms an airflow within the interior A of the protective housing 10k from intake port 19a to exhaust port 18a. As a result, fan 17 generates an airflow that passes from intake port 19a through the interior A of the protective housing 10k and is exhausted from exhaust port 18a. Through the action of fan 17, intake port 19a draws outside air from the external space C into the interior A of the protective housing 10k via the airflow path of intake duct 19. Similarly, through the action of fan 17, exhaust port 18a discharges gas from the interior A of the protective housing 10k to the external space C via the airflow path of exhaust duct 18.

[0060] In this embodiment, the fan 17 is installed in the exhaust port 18a. Therefore, in this embodiment, the intake port of the fan 17 functions as the exhaust port 18a. This reduces pressure loss and makes it easier to maintain the airflow velocity of the gas at the exhaust port 18a compared to the case where the airflow 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 positioned in the 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 the gas containing the refrigerant gas from the lower region of the protective housing 10k and discharges it to the outside through the air passage of the exhaust duct 18.

[0062] The fan 17 may be located inside, for example, the exhaust duct 18. That is, the fan 17 only needs to be installed in communication with the exhaust port 18a. Note that "installed in communication with the exhaust port 18a" means that it is located inside a sealed space (for example, the exhaust duct 18 in this embodiment) connected to the exhaust port 18a.

[0063] An example of installing a fan in a location not connected to the exhaust port is placing the fan in the middle of the intake duct. In this case, air is drawn into the protective enclosure from the fan's intake port. This pushes the gas inside the protective enclosure out and guides it to the exhaust port, where it is then discharged through the exhaust duct. However, in this case, multiple devices placed inside the protective enclosure may obstruct the airflow towards the exhaust port, making smooth exhaust difficult. Furthermore, if there are gaps in the protective enclosure, air is likely to leak out through these gaps, potentially resulting 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 densely arranged inside the protective enclosure 10k, the gas inside the protective enclosure 10k can be drawn in through the exhaust port 18a, and the inside of the protective enclosure 10k can be efficiently ventilated.

[0065] The fan 17 is connected to and controlled by the control device 41 (see Figure 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 within the protective enclosure 10k will be explained based on Figure 4.

[0067] In this embodiment, since the refrigerant gas is heavier than air, it tends to accumulate near the bottom surface 10p inside the protective housing 10k. Therefore, in order to efficiently discharge the refrigerant from inside the protective housing 10k to the outside, it is necessary to carry the refrigerant accumulating at the bottom of the protective housing 10k 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 air and refrigerant gas and the wind speed of the fan 17.

[0068] Here, we focus on the distance L1 from the bottom surface 10p of the protective housing 10k to the center CL of the exhaust port 18a, and the wind speed U of the gas drawn in from the exhaust port 18a. If the distance L1 is large, or if the wind speed U is small, the inertial force of the airflow generated by the fan 17 is insufficient to overcome 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, when L1, g, U, ρ1, ρ0, and η are set as follows, it is preferable that the ventilation device 10 of this embodiment satisfies the following (Equation 1) for each of these parameters.

[0070] L1[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 ]:Gravity acceleration 9.8 U[m / s]: Wind speed of the gas drawn in from exhaust port 18a ρ1[kg / m 3 ]: Density of refrigerant gas ρ0 [kg / m 3 : Density of air η: Constant 3.27

[0071] [Number]

[0072] In the present embodiment, a fan 17 is provided at the exhaust port 18a, and the center CL of the exhaust port 18a is also the center of the suction port of the fan 17. The distance L1 from the bottom surface 10p of the protective housing 10k to the center CL of the exhaust port 18a 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. Also, in the present embodiment, the density (ρ1) of the refrigerant gas is higher than the density (ρ0) of air (ρ1 > ρ0).

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

[0074] Therefore, on the left side of Equation (1), the value increases by increasing the inertial force sucked from the exhaust port 18a by the action of the fan 17. Also, on the left side of Equation (1), the value decreases because the force by which the refrigerant gas tends to sink downward due to gravity in the interior A of the protective housing 10k increases. Equation (1) shows that when the ratio of the numerator to the denominator is larger than the constant shown on the right side, the refrigerant gas in the interior A of the protective housing 10k can be quickly ventilated.

[0075] Next, a test apparatus and a test method for calculating Equation (1) will be described. As a test apparatus, a test apparatus that mimics protective enclosure 10k (hereinafter simply referred to as protective enclosure 10k) is prepared. Protective enclosure 10k as a test apparatus is a rectangular parallelepiped with a base 10p width x depth of 0.70m x 0.60m and a height of 0.47m.

[0076] The protective enclosure 10k, which serves as a test enclosure, is provided with an intake duct 19 and an exhaust duct 18, both extending linearly in the vertical direction, as shown in Figure 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 also provided at the exhaust port 18a of the exhaust duct 18.

[0077] A refrigerant gas supply pipe was placed inside the protective enclosure 10k, which served as a test enclosure. The refrigerant gas supply pipe supplied refrigerant gas to the interior A of the protective enclosure 10k, which acted as a source of refrigerant gas leakage in place of the refrigerant circuit CR. Furthermore, multiple refrigerant sensors 16 were placed inside the interior A of the protective enclosure 10k to the extent that the overall refrigerant gas concentration distribution within the interior A of the protective enclosure 10k could be determined.

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

[0079] Next, the fan 17 was started. This caused the refrigerant gas inside the protective housing 10k to be discharged from the exhaust port 18a. Furthermore, the time required from the start of operation of the fan 17 until the refrigerant gas concentration at all refrigerant sensors 16 fell below a preset concentration was measured.

[0080] In this test, the airflow of fan 17 was set to 30 m³. 3 Let the fan speed U be 4.24 m / s and the density ρ1 be 1.8 kg / m³. 3The refrigerant gas used was [specified gas]. This test was also conducted under two conditions, a first and a second, in which the distance L1 from the bottom surface 10p of the protective housing 10k to the center CL of the exhaust port 18a was varied. Under the first condition, the distance L1 was set to 0.11m. Under the second condition, the distance L1 was set to 0.141m.

[0081] Figure 5 is a graph summarizing the test results under the first and second conditions. As shown in Figure 5, it was confirmed that the ventilation time could be shortened by lowering the height (distance L1) of the center CL of the fan 17.

[0082] Furthermore, 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. Considering the hydrodynamic characteristics, reducing the distance L1 from the bottom surface 10p to the center CL of the exhaust port 18a in the above-mentioned test apparatus will proportionally shorten the exhaust time. Similarly, the exhaust time is proportional to the gravitational force (g × (ρ1 - ρ0) / ρ0) acting on the refrigerant gas due to the density difference with the air, and inversely proportional to the wind velocity U of the gas drawn into the exhaust port 18a. From this, by setting the left side of (Equation 1) to a specific value (constant η) or more, the exhaust time by the ventilation device 10 can be made (145) seconds or less. Here, based on the results of this test, the constant η required to make the exhaust time of the ventilation device 10 (145) seconds or less was calculated, and the above-mentioned 3.27 was obtained.

[0083] In the ventilation device 10 of this embodiment, the distance L1 from the bottom surface 10p to the center CL of the exhaust port 18a is preferably 0.11m or more. Tests using the above-described test apparatus confirmed that if the exhaust port 18a is too close to the bottom surface 10p, the high-velocity gas drawn into the exhaust port 18a will experience pressure loss due to wall friction between it and the bottom surface 10p, and the airflow rate at the operating point of the fan 17 tends to decrease. As a result of the reduced airflow rate, refrigerant gas tends to accumulate in the corner region of the protective housing 10k within the interior A of the protective housing 10k. Therefore, in this embodiment, by setting the distance L1 from the bottom surface 10p to the center CL of the exhaust port 18a to 0.11m or more, the circulation of refrigerant gas within the interior A of the protective housing 10k can be promoted. Furthermore, since the indoor unit 2 is mounted on the bottom surface 10p, if the distance between the center CL of the exhaust port 18a and the bottom surface 10p is lower than 0.11m, the exhaust port 18a is more likely to be blocked by the equipment, which may reduce the suction efficiency at the exhaust port 18a. By setting the distance L1 from the bottom surface 10p to the center CL of the exhaust port 18a to 0.11m or more, it becomes easier to ensure the suction efficiency at the exhaust port 18a.

[0084] The airflow velocity U of the gas drawn in from the exhaust port 18a can be determined by dividing the airflow generated by the fan 17 by the cross-sectional area of ​​the exhaust port 18a. Furthermore, IEC-60335-2-40 ED7 recommends that the airflow from the fan 17 exceed the minimum airflow rate specified by formula GG.16, 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 Embodiment 1) As shown in Figure 4, the ventilation device 10 of this embodiment comprises a protective housing 10k, an intake port 19a, an exhaust port 18a, and a fan 17. The protective housing 10k houses at least a portion of the refrigerant circuit CR through which the refrigerant circulates. The intake port 19a draws in outside air into the interior A of the protective housing 10k. The exhaust port 18a discharges 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 airflow 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 vaporized refrigerant gas is higher than the density of air. Furthermore, the following L1, g, U, ρ1, ρ0, and η satisfy the following relationship (Equation 1). L1[m]: Distance from the bottom surface 10p of the protective housing 10k to the center of the exhaust port 18a g[m / s 2 ]:Gravity acceleration 9.8 U[m / s]: Wind speed of the gas drawn in from exhaust port 18a ρ1[kg / m 3 ]: Density of refrigerant gas ρ0[kg / m 3 ]: air density η: constant 3.27

[0086]

number

[0087] This configuration allows the intake performance of the fan 17 and the position of the exhaust port 18a to be determined according to the density of the refrigerant gas. Therefore, there is no need to give the fan 17 excessive airflow performance, and the ventilation device 10 can be made inexpensive. Furthermore, the degree of freedom in the placement of the exhaust port 18a is increased, enabling efficient ventilation without bringing the exhaust port 18a too 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. With the above configuration, by ensuring the wind velocity U and the placement of the exhaust port 18a that satisfy (Equation 1), the efficient arrangement of multiple devices inside A of the protective housing 10k can be achieved, and the protective housing 10k can be made smaller. Furthermore, with this configuration, the fan 17 is installed in communication with the exhaust port 18a. That is, the fan 17 is placed in a sealed space (exhaust duct 18 in this embodiment) where the exhaust port 18a opens, such as an exhaust duct 18. Therefore, the airflow from the fan 17 efficiently draws the gas inside the protective housing 10k through the exhaust port 18a. In addition, with this configuration, since the exhaust direction D2 and the intake direction D1 are in different directions, it is easier to promote air circulation inside the protective housing 10k. As a result, it is less likely that residual areas of refrigerant gas will form inside the protective housing 10k. Consequently, it becomes easier to discharge refrigerant gas from every corner of the protective housing 10k.

[0088] In the ventilation device 10 of this embodiment, the distance L1 from the bottom surface 10p of the protective housing 10k to the center of the exhaust port 18a is preferably 0.11m or more. With this configuration, pressure loss due to wall friction between the fast-flowing gas drawn into the exhaust port 18a and the bottom surface 10p can be suppressed, and a decrease in the airflow rate at the operating point of the fan 17 can be avoided. In other words, the air drawn in from the exhaust port 18a from the interior A of the protective housing 10k promotes the circulation of air inside the interior A of the protective housing 10k, making it easier to discharge refrigerant gas from all corners of the interior A of the protective housing 10k. Furthermore, by setting the distance L1 from the bottom surface 10p to the center CL of the exhaust port 18a to 0.11m or more, the exhaust port 18a is less likely to be blocked by the bottom surface 10p and equipment mounted on the bottom surface 10p. This makes it easier to ensure 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, the 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 heads towards the exhaust port 18a. As a result, the air introduced into the interior A of the protective housing 10k promotes the circulation of air inside the interior A of the protective housing 10k, making it easier to discharge refrigerant gas from all corners of the interior A of the protective housing 10k.

[0090] In the ventilation device 10 of this embodiment, the fan 17 is positioned at the exhaust port 18a. With this configuration, the intake port of the fan 17 functions as the exhaust port 18a. Therefore, it becomes easier to ensure the airflow velocity of the gas drawn in at the exhaust port 18a, and the time required to ventilate the inside A of the protective housing 10k can be shortened.

[0091] As shown in Figure 1, the indoor unit 2 of this embodiment comprises the ventilation device 10 described above, at least a part of the refrigerant circuit CR, and a secondary heat exchanger (heat transfer medium heat exchanger) 13. The secondary heat exchanger 13 is located inside A of the protective housing 10k. The secondary heat exchanger 13 exchanges heat between the refrigerant and a heat transfer medium different from the refrigerant (water in Embodiment 1). With this configuration, the indoor unit 2 can transfer heat or cold from the refrigerant circuit CR to the heat transfer medium via the secondary heat exchanger 13 and utilize it.

[0092] The indoor unit 2 of this embodiment is equipped with a secondary circuit (heat transfer medium circuit) C2. The secondary circuit C2 provides the heat transfer medium, which has exchanged heat with the refrigerant by the secondary heat exchanger 13, to the heating and cooling system 30a. With this configuration, the heat or cold from the refrigerant circuit CR can be used for the heating and cooling operation of the heating and cooling system 30a via the secondary circuit C2.

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

[0094] (Embodiment 2) Figure 6 is a schematic diagram of the ventilation device 110 of Embodiment 2. Components identical to those in the above-described embodiment are denoted by the same reference numerals, and their descriptions are omitted.

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

[0096] Similar to the embodiment described above, the protective housing 10k houses at least a portion of the refrigerant circuit CR. The refrigerant flows through the refrigerant circuit CR. In this embodiment, the density of the vaporized refrigerant gas is lower than the density of air. Therefore, the refrigerant gas is lighter than air and accumulates near the top surface 10q inside the protective housing 10k A. Ammonia is an example of such a refrigerant.

[0097] In this embodiment, the refrigerant sensor 116 is positioned along the top surface 10q of the protective housing 10k. Therefore, the refrigerant sensor 116 can immediately detect the refrigerant gas accumulating 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 placed 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 the air to be diffused over a wide area within the interior A of the protective housing 10k in the air path from the intake port 19a to the exhaust port 118a. As a result, the formation of a residual area of ​​refrigerant gas within the interior A of the protective housing 10k can be suppressed.

[0099] In this embodiment, the intake direction D1 and the exhaust direction D2 are orthogonal to each other. Therefore, the air introduced from the intake port 19a into the interior A of the protective housing 10k strikes the inner surface of the protective housing 10k before heading towards the exhaust port 118a. As a result, the air introduced into the interior A of the protective housing 10k promotes the circulation of air within the interior A of the protective housing 10k. Consequently, it becomes less likely for residual refrigerant gas to form in the interior A of the protective housing 10k, and the ventilation efficiency of the refrigerant gas can be improved.

[0100] We focus on the distance L2 from the top surface 10q of the protective housing 10k to the center CL of the exhaust port 118a, and the wind speed U of the gas drawn in from the exhaust port 118a. If the distance L2 is large, or if the wind speed U is small, the inertial force of the airflow generated by the fan 17 is insufficient to overcome 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 height arrangement of the exhaust port 118a is determined by focusing on the relationship between the inertial force of the airflow and the buoyancy acting on the refrigerant gas.

[0101] Here, when L2, g, U, ρ1, ρ0, and 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 ]:Gravity acceleration 9.8 U[m / s]: Wind speed of the gas drawn in from exhaust port 118a L2[m]: Distance from the top surface 10q of the protective enclosure 10k to the center CL of the exhaust port 118a. ρ1[kg / m 3 ]: Density of refrigerant gas ρ0[kg / m 3 ]: air density

[0103]

number

[0104] In this embodiment, a fan 17 is provided at the exhaust port 118a, and the center CL of the exhaust port 118a is the center of the intake port of the fan 17. The distance L1 from the top surface 10q of the protective housing 10k to the center CL of the exhaust port 118a 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 refers to the midpoint between the upper and lower ends of the exhaust port 118a, regardless of the opening direction of the exhaust port 118a. Also, in this embodiment, the density of the refrigerant gas (ρ1) is lower than the density of air (ρ0) (ρ1 < ρ0).

[0105] Equation (2) is derived based on the calculation test in Embodiment 1 described above. Equation (2) shows that when the ratio of the numerator to the denominator is greater than the constant shown on the right side, the refrigerant gas inside A of the protective enclosure 10k can be ventilated quickly.

[0106] In the ventilation device 110 of this embodiment, the distance L2 from the top surface 10q to the center CL of the exhaust port 118a is preferably 0.11 [m] or more. This suppresses pressure loss caused by wall friction between the high-velocity gas drawn into the exhaust port 118a and the top surface 10q, and prevents a decrease in the airflow rate at the operating point of the fan 17.

[0107] (Summary of Embodiment 2) The ventilation device 110 of this embodiment comprises a protective housing 10k, an intake port 19a, an exhaust port 118a, and a fan 17. The protective housing 10k houses at least a portion of the refrigerant circuit CR through which the refrigerant circulates. The intake port 19a draws in outside air into the interior A of the protective housing 10k. The exhaust port 118a discharges 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 airflow 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 vaporized refrigerant gas is lower than the density of air. Furthermore, the following L2, g, U, ρ1, ρ0, and η satisfy the following relationship (Equation 2). L2[m]: Distance from the top surface 10q of the protective enclosure 10k to the center CL of the exhaust port 118a. g[m / s 2 ]:Gravity acceleration 9.8 U[m / s]: Wind speed of the gas drawn in from exhaust port 118a ρ1[kg / m 3 ]: Density of refrigerant gas ρ0[kg / m 3 ]: air density η: constant 3.27

[0108]

number

[0109] This configuration allows the intake performance of the fan 17 and the position of the exhaust port 118a to be determined according to the density of the refrigerant gas. Therefore, there is no need to give the fan 17 excessive airflow performance, and the ventilation device 110 can be made inexpensive. Furthermore, the degree of freedom in the placement of the exhaust port 118a is increased, enabling efficient ventilation without having to bring the exhaust port 118a too close to the bottom surface 10p of the protective housing 10k. In addition, with this configuration, since the fan 17 is installed in communication with the exhaust port 118a, the airflow from the fan 17 can efficiently draw in the gas inside A of the protective housing 10k from the exhaust port 118a. Furthermore, with this configuration, since the exhaust direction D2 and the intake direction D1 are in different directions, it is less likely that a residual area of ​​refrigerant gas will form inside A of the protective housing 10k, making it easier to discharge the refrigerant gas from inside A of the protective housing 10k.

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

[0111] (Embodiment 3) Figure 7 is a schematic diagram illustrating the configuration of the 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 its heat extraction means. That is, the air conditioner 201 of this embodiment does not utilize geothermal energy as in the above embodiment, but instead uses an outdoor heat exchanger 71 that performs heat exchange between outdoor air and the refrigerant to heat and cool the refrigerant. Components that are the same as those in the above embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0112] The air conditioner 201 of this embodiment comprises an indoor unit 202, an outdoor unit 203, a heat pump device 220A, a secondary 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 device 220A is positioned 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 discharges refrigerant gas leaking from the refrigerant circuit CR of the heat pump device 220A into the external space C.

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

[0114] In heating operation mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 11 flows into the secondary heat exchanger 13 through the four-way valve 12. The high-temperature, high-pressure gaseous refrigerant condenses and liquefies while releasing heat by exchanging heat with the water flowing through the secondary circuit C2 in the secondary heat exchanger 13, becoming a high-pressure liquid refrigerant. In addition, the heat released from the refrigerant is transferred to the water flowing through the secondary circuit C2 on the load 30 side, warming the water. The high-pressure liquid refrigerant that leaves the secondary heat exchanger 13 then passes through the expansion valve 14 to become a low-temperature, low-pressure liquid refrigerant, which 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 and evaporates and gasifies. The gasified low-pressure gaseous refrigerant is then drawn back into the compressor 11 and circulates through the refrigerant circuit CR.

[0115] In cooling operation mode, the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 11 flows into the outdoor heat exchanger 71 through the four-way valve 12. The high-temperature, high-pressure gaseous refrigerant condenses and liquefies while releasing heat as it exchanges heat with the outside air in the outdoor heat exchanger 71, becoming a high-pressure liquid refrigerant. The high-pressure liquid refrigerant that leaves 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 heat exchanger 13. The low-temperature, low-pressure liquid refrigerant that flows into the secondary heat exchanger 13 exchanges heat with the water flowing in the secondary circuit C2, which is on the load 30 side, absorbing heat as it evaporates and gasifies, and the heat released from the load 30 side to the water in the secondary circuit C2 is transferred to the refrigerant, cooling the water flowing in the secondary circuit C2. After that, the gasified refrigerant is 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 comprises an indoor unit 202 and an outdoor unit 203. The outdoor unit 203 has at least a portion of the refrigerant circuit CR and an outdoor heat exchanger 71 that performs heat exchange between the refrigerant and the outside air. Also, similar to the embodiment described above, the indoor unit 202 comprises a ventilation device 10 similar to the embodiment described above, at least a portion of the refrigerant circuit CR, a secondary heat exchanger 13, a water storage tank 30b, and a secondary circuit C2. The secondary heat exchanger 13 is located inside the protective housing 10k and exchanges heat between the refrigerant and water (heat transfer medium). The water storage tank 30b stores water. The secondary circuit C2 heats or cools the water stored in the water storage tank with the water that has exchanged heat with the refrigerant by the secondary heat exchanger 13.

[0117] With this configuration, since the air conditioner 201 has an outdoor unit 203, it is possible to cool or heat the refrigerant with outside air, and the heat or cold of the outside air can be used to operate the heating and cooling system 30a or to heat or cool the water stored in the water storage tank 30b. Furthermore, with 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 will be naturally discharged from inside the outdoor unit 203 into the external space C.

[0118] While embodiments of this disclosure have been described above, this disclosure is not limited to the configurations of the embodiments described above, and the following configurations and methods may also be adopted. Furthermore, the configurations and methods described herein can be combined as appropriate, within the bounds of non-inconsistency.

[0119] For example, in each of the embodiments described above, the case in which the exhaust duct and intake duct extend uniformly in the vertical direction was explained. However, the exhaust duct and intake duct may be bent, or they may extend uniformly in the horizontal direction, for example. Also, in each embodiment, the case in which 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 was explained. However, in cases where the exhaust duct or intake duct extends upward from the floor surface, the exhaust port and intake port may be located at the upper ends of the exhaust duct and intake duct, respectively. [Explanation of Symbols]

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

Claims

1. A protective enclosure that houses at least a portion of the refrigerant circuit through which the refrigerant circulates, An air intake port that opens inside the protective housing and takes in outside air into the protective housing, An exhaust port that opens inside the protective housing and discharges gas from inside the protective housing, The system includes a fan that generates an airflow that passes from the intake port through the inside of the protective housing and is exhausted from the exhaust port, The intake port is configured to blow air into the interior of the protective housing in the direction of intake. The exhaust port is configured to exhaust air in a direction that draws in air from inside the protective housing. The exhaust direction is different from the intake direction. The density of the refrigerant gas obtained by vaporizing the refrigerant is higher than the density of air. The following L １ , g, U, ρ １ ρ ０ A ventilation system in which η satisfies the following relationship (Equation 1). L 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 the gas drawn in from the exhaust port. ρ １ [kg / m ３ ]: Density of the refrigerant gas ρ ０ [kg / m ３ : Air density η: constant 3.27 [Math 1]

2. A protective enclosure that houses at least a portion of the refrigerant circuit through which the refrigerant circulates, An air intake port that opens inside the protective housing and takes in outside air into the protective housing, An exhaust port that opens inside the protective housing and discharges gas from inside the protective housing, The system includes a fan that generates an airflow that passes from the intake port through the inside of the protective housing and is exhausted from the exhaust port, The intake port is configured to blow air into the interior of the protective housing in the direction of intake. The exhaust port is configured to exhaust air in a direction that draws in air from inside the protective housing. The exhaust direction is different from the intake direction. The density of the refrigerant gas obtained by vaporizing the refrigerant is lower than the density of air. The following L ２ , g, U, ρ １ ρ ０ A ventilation system in which η satisfies the following relationship (Equation 2). L 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 the gas drawn in from the exhaust port. ρ １ [kg / m ３ ]: Density of the refrigerant gas ρ ０ [kg / m ３ ]: Density of air η: constant 3.27 [Math 2]

3. The intake direction and the exhaust direction are orthogonal to each other. The ventilation device according to claim 1 or 2.

4. The fan is positioned at the exhaust port. The ventilation device according to claim 1 or 2.

5. A ventilation device according to claim 1 or 2, At least a part of the refrigerant circuit, The protective housing is disposed inside a heat transfer medium heat exchanger that exchanges heat between the refrigerant and a heat transfer medium different from the refrigerant. Indoor unit.

6. The system includes a heat transfer circuit that provides the heat transfer medium, which has exchanged heat with the refrigerant by the heat transfer medium heat exchanger, to a heating and cooling system. The indoor unit according to claim 5.

7. A water storage tank for storing water, The system includes a heat transfer circuit that heats or cools the water stored in the water storage tank using the heat transfer medium that has exchanged heat with the refrigerant by the heat transfer heat exchanger. The indoor unit according to claim 5.

8. The indoor unit according to claim 6, The system comprises at least a portion of the refrigerant circuit and an outdoor unit having an outdoor heat exchanger that performs heat exchange between the refrigerant and the outside air. Air conditioner.

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