Ventilation and air conditioning system

Abstract

The ventilation and air conditioning system (100) comprises a ventilation device (1), a first damper device (10) having an airflow path switching means, a coil device (20) having a heat exchange means, a refrigerant leak detection means for detecting refrigerant leakage from the heat exchange means, and a control circuit unit (50) that controls the ventilation device (1), the first damper device (10), and the coil device (20) based on the detection status of the refrigerant leak detection means. The control circuit unit (50) switches the airflow path switching means of the first damper device (10) to select the main airflow path (111) and supplies air to the room by blowing air through the coil device (20) if the refrigerant leak detection means does not detect refrigerant leakage, and switches the airflow path switching means of the first damper device (10) to select the secondary airflow path and supplies air to the room without blowing air through the coil device (20).

Description

Technical Field

[0001] The present disclosure relates to a ventilation and air conditioning system including a ventilation device capable of supplying and exhausting air, a coil device for temperature-adjusting outdoor air taken in by the ventilation device, and a damper device for switching air passages.

Background Art

[0002] Conventionally, there is known a duct-type air conditioner including an air conditioning duct connected to the downstream side of an indoor unit of an air conditioner through which an air conditioning airflow is ventilated, an exhaust duct connected to the upstream side of the air conditioning duct for discharging leaked refrigerant outdoors, and a damper for switching whether the air conditioning airflow flowing out from the indoor unit flows into the air conditioning duct or the exhaust duct (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, since the duct-type air conditioner of Patent Document 1 assumes an indoor unit that circulates indoor air, it does not mention equipment for taking in outdoor air. In particular, when the indoor airtightness is high, the indoor becomes negative pressure, so there is a problem that sufficient ventilation cannot be ensured and leaked refrigerant cannot be sufficiently exhausted. Further, even if the indoor unit of the air conditioner is replaced with an outdoor unit that takes in outdoor air for temperature adjustment, when the refrigerant leaks, the refrigerant flows into the room together with the outside air by the blower of the outdoor unit, so that the refrigerant accumulates in the room, and there is a problem that a flammable region with a high refrigerant concentration is generated in the room.

[0005] This disclosure is made in view of the above, and aims to provide a ventilation and air conditioning system that can supply only fresh outdoor air to the room without introducing leaked refrigerant into the room, even if refrigerant leaks from the coil device. [Means for solving the problem]

[0006] The ventilation and air conditioning system disclosed herein includes a ventilation device having an air intake port for drawing in outdoor air, an air outlet for blowing the air drawn in from the air intake port into the room, an air supply passage connecting the air intake port and the air supply outlet, and an air supply fan provided in the air supply passage; a first connection port into which the air blown out from the ventilation device flows in, a second and third connection ports for discharging the air that has flowed into the first connection port, and a main connection port connecting the first and second connection ports. The system includes a first damper device having an air passage, a secondary air passage connecting a first connection port and a third connection port, and an air passage switching means for switching between the main air passage and the secondary air passage; a coil device having a first vent into which air flows from the first damper device, a second vent for releasing the air that has flowed into the first vent, and a heat exchange means provided in the air passage connecting the first vent and the second vent, which adjusts the temperature by exchanging heat between the air flowing in from the first vent and the refrigerant. The ventilation and air conditioning system comprises a first duct connecting the supply air outlet of the ventilation device to the first connection port of the first damper device, a second duct connecting the second connection port of the first damper device to the first vent of the coil device, a third duct connecting the second vent of the coil device to the first indoor supply air outlet provided in the room, a fourth duct connecting the third connection port of the first damper device to the second indoor supply air outlet provided in the room, a refrigerant leak detection means for detecting refrigerant leakage from the heat exchange means, and a control circuit unit that controls the ventilation device, the first damper device, and the coil device based on the detection state of the refrigerant leak detection means. If the coil device is stopped, regardless of whether the refrigerant leak detection means has detected a refrigerant leak, The airflow switching mechanism of the first damper device is switched to select the secondary airflow path, supplying air to the room without supplying it to the coil device. [Effects of the Invention]

[0007] According to this disclosure, even if refrigerant leaks from the coil device, it is possible to provide a ventilation and air conditioning system that can supply only fresh outdoor air to the room without introducing the leaked refrigerant into the room. [Brief explanation of the drawing]

[0008] [Figure 1] Configuration diagram showing the normal operation state of the ventilation and air conditioning system according to Embodiment 1. [Figure 2] Configuration diagram showing the state of the ventilation and air conditioning system during refrigerant leakage according to Embodiment 1 [Figure 3] Block diagram showing the configuration of the control circuit section of the ventilation and air conditioning system according to Embodiment 1. [Figure 4] A flowchart showing a control method in the case of refrigerant leakage in the ventilation and air conditioning system according to Embodiment 1. [Figure 5] Configuration diagram showing the normal operation state of the ventilation and air conditioning system according to Embodiment 2. [Figure 6] Configuration diagram showing the state of the ventilation and air conditioning system during refrigerant leakage according to Embodiment 2 [Figure 7] Configuration diagram showing the normal operating state of the ventilation and air conditioning system according to Embodiment 3. [Figure 8] Configuration diagram showing the state of the ventilation and air conditioning system during refrigerant leakage according to Embodiment 3 [Figure 9] Configuration diagram showing the state of exhaust from two exhaust air passages in the ventilation and air conditioning system according to Embodiment 3. [Modes for carrying out the invention]

[0009] The ventilation and air conditioning system according to the embodiment will be described in detail below with reference to the drawings.

[0010] Embodiment 1. Figure 1 is a configuration diagram showing the state of the ventilation and air conditioning system according to Embodiment 1 during normal operation. Figure 2 is a configuration diagram showing the state of the ventilation and air conditioning system according to Embodiment 1 during refrigerant leakage. Figure 3 is a block diagram showing the configuration of the control circuit section of the ventilation and air conditioning system according to Embodiment 1. Figure 1 shows the position of the airflow switching damper 11 during normal operation. Figure 2 shows the position of the airflow switching damper 11 during refrigerant leakage. Furthermore, the airflow is indicated by arrows in Figures 1 and 2.

[0011] Figure 1 shows the main components of the ventilation and air conditioning system 100 according to Embodiment 1, which include a ventilation device 1, a first damper device 10, and a coil device 20. The ventilation device 1 includes an air supply fan 2, an exhaust fan 3, and a total heat exchanger 4. The coil device 20 has a direct expansion coil 21 for air conditioning, which is a heat exchange means. The first damper device 10 has a wind path switching damper 11, which is a wind path switching means for switching the air supply path to the room. The first duct 40 connects the ventilation device 1 and the first damper device 10. The second duct 41 connects the first damper device 10 and the coil device 20. The third duct 42 connects the coil device 20 and the first indoor air supply outlet 92. The fourth duct 43 connects the first damper device 10 and the second indoor air supply outlet 95. The fifth duct 44 connects the ventilation device 1 to the indoor exhaust intake port 93.

[0012] The ventilation device 1 is covered by a box-shaped casing 5. The outdoor side of the casing 5 is provided with an air intake port 6 and an exhaust outlet port 9, while the indoor side of the casing 5 is provided with an air intake port 7 and an exhaust intake port 8. Inside the ventilation device 1, the air intake port 6 and the air intake port 7 are connected to form an air intake passage that supplies outdoor air OA, drawn in from the outdoor air intake port 91, to the room as air intake SA. The exhaust outlet port 8 and the exhaust outlet port 9 are connected to form an exhaust passage that discharges indoor air RA to the outside as exhaust air EA through the outdoor exhaust outlet port 94.

[0013] The supply air blower 2 is positioned in the supply air passage within the ventilation device 1 and generates a supply airflow from the supply air intake 6 to the supply air outlet 7. The exhaust air blower 3 is positioned in the exhaust air passage within the ventilation device 1 and generates an exhaust airflow from the exhaust air intake 8 to the exhaust air outlet 9. The total heat exchanger 4 is positioned between the supply air passage and the exhaust air passage, and heat exchange occurs between the outdoor air OA flowing through the supply air passage and the indoor air RA flowing through the exhaust air passage as the supply air passage and the exhaust air passage intersect inside the total heat exchanger 4.

[0014] As shown in Figure 3, the ventilation device 1, coil device 20, and first damper device 10 are connected to a control circuit unit 50. A remote control 51 is connected to the control circuit unit 50 to receive instructions for operating the ventilation device 1 and the coil device 20. The control circuit unit 50 controls the connected supply air blower 2, exhaust air blower 3, airflow switching damper 11, direct expansion coil 21, and shut-off valve 31 according to instructions from the remote control unit 51. The control circuit unit 50 and the remote control unit 51 are connected by bidirectional communication. The remote control unit 51 transmits the settings to the control circuit unit 50, and the control circuit unit 50, upon receiving the settings, controls each connected load according to the settings of the remote control unit 51. The loads here are the supply air blower 2, exhaust air blower 3, airflow switching damper 11, direct expansion coil 21, and shut-off valve 31. The control circuit unit 50 transmits the operating status and abnormality status of each load to the remote control unit 51, and the remote control unit 51, upon receiving this information, can display the operating status and abnormality status. The ventilation device 1, coil device 20, and first damper device 10 are each connected to the remote control 51 by a communication unit 52. The first damper device 10 is opened and closed only by signals from the control circuit unit 50 and does not accept manual operation commands using the remote control 51.

[0015] As shown in Figure 1, fresh outside air blown out from the air supply outlet 7 of the ventilation device 1 is supplied to the first damper device 10 via the first duct 40. The first damper device 10 has a first connection port 15, a second connection port 16, and a third connection port 17 on its outer casing. The second connection port 16 is provided on the outer casing of the first damper device 10 opposite the surface on which the first connection port 15 is provided. The third connection port 17 is provided on one of the surfaces of the outer casing of the first damper device 10 that shares an edge with one side of the surface on which the first connection port 15 is provided, and also shares an edge with one side of the surface on which the second connection port 16 is provided. The first duct 40, which is connected to the air supply outlet 7 of the ventilation device 1, is connected to the first connection port 15. The second duct 41, which is connected to the coil device 20, is connected to the second connection port 16. The fourth duct 43, which is connected to the second indoor air supply outlet 95, is connected to the third connection port 17. The air passage connecting the first connection port 15 and the second connection port 16 is the main air passage 111, and the air passage connecting the first connection port 15 and the third connection port 17 is the secondary air passage 112. Furthermore, the first damper device 10 is equipped with an air passage switching damper 11 that selects between the main air passage 111 and the secondary air passage 112. Normally, when the air passage switching damper 11 is switched to open the second connection port 16 and close the third connection port 17, the main air passage 111 is selected as shown in Figure 1, and the air blown out from the air supply outlet 7 of the ventilation device 1 is supplied to the coil device 20 via the main air passage 111 and the second duct 41 of the first damper device 10. Furthermore, by switching the airflow switching damper 11 to close the second connection port 16 and open the third connection port 17, the secondary airflow path 112 is selected as shown in Figure 4, and the air blown out from the supply air outlet 7 of the ventilation device 1 is supplied directly into the room via the secondary airflow path 112 and the fourth duct 43 of the first damper device 10.

[0016] The coil device 20 incorporates a direct expansion coil 21 through which the refrigerant flows. On the outer shell of the coil device 20, there are provided a first ventilation opening 26 for connecting a second duct 41 connected to the first damper device 10, and a second ventilation opening 27 for connecting a third duct 42 connected to a first indoor air supply outlet 92 on the surface opposite to the surface where the first ventilation opening 26 is provided. The fresh outdoor air that has passed through the second duct 41 from the first damper device 10 is heat-exchanged and temperature-controlled in the direct expansion coil 21. The fresh outdoor air temperature-controlled by the direct expansion coil 21 is supplied into the room from the first indoor air supply outlet 92 through the third duct 42.

[0017] A shut-off valve device 30 for shutting off the refrigerant in case of refrigerant leakage is connected to the coil device 20. Inside the shut-off valve device 30, a shut-off valve 31 for opening and closing the refrigerant pipe connected to the direct expansion coil 21 is provided. The shut-off valve 31 is provided on both the gas refrigerant side and the liquid refrigerant side. When refrigerant leakage is detected in the coil device 20, the shut-off valve 31 closes to shut off the refrigerant flowing inside the refrigerant pipe and suppress the spread of refrigerant leakage.

[0018] Next, the control algorithm of the ventilation and air conditioning system 100 according to Embodiment 1 will be described. FIG. 4 is a flowchart showing a control method in case of refrigerant leakage in the ventilation and air conditioning system according to Embodiment 1.

[0019] In step S110, the control circuit unit 50 determines whether there is refrigerant leakage. If the control circuit unit 50 determines in step S110 that there is refrigerant leakage (S110: Yes), the process proceeds to step S120. If the control circuit unit 50 determines that there is no refrigerant leakage (S110: No), the process returns to step S110 and waits until there is refrigerant leakage.

[0020] In step S120, the control circuit unit 50 switches the airflow switching damper 11 located in the first damper device 10 to select a secondary airflow path 112 that closes the second connection port 16 and opens the third connection port 17. The fourth duct 43 is installed so that the air blown out from the supply air outlet 7 of the ventilation device 1 is supplied directly into the room from the second indoor supply air outlet 95. Therefore, if a refrigerant leak occurs, fresh outside air is supplied directly into the room without airflow passing through the coil device 20.

[0021] In step S130, the control circuit unit 50 closes the shut-off valve 31 in the shut-off valve device 30 from open to closed. Closing the shut-off valve 31 prevents the refrigerant leak from spreading.

[0022] In step S140, the control circuit unit 50 determines whether or not ventilation is in operation. If the ventilation device 1 is operating when a refrigerant leak is detected (S140: Yes), the control circuit unit 50 continues the operation. If the ventilation device 1 is stopped (S140: No), the control circuit unit 50 proceeds to step S150 to operate the ventilation device 1. When the ventilation device 1 is operated, the control circuit unit 50 issues operation commands to both the supply fan 2 and the exhaust fan 3, so that fresh outside air is introduced and indoor air is exhausted, thus ensuring a good indoor environment.

[0023] In step S160, the control circuit unit 50 determines whether the refrigerant leakage abnormality has been resolved. As long as the refrigerant leakage abnormality is not resolved (S160: No), the control circuit unit 50 maintains the operation of the ventilation device 1 and the position of the airflow switching damper 11. When the refrigerant leakage abnormality is resolved (S160: Yes), the control circuit unit 50 proceeds to step S170, returning the position of the airflow switching damper 11 to its original position and selecting the main airflow path 111, so that the fresh outside air supplied by the ventilation device 1 can once again circulate through the coil device 20.

[0024] Thus, in the ventilation and air conditioning system 100 according to Embodiment 1, when a refrigerant leak occurs, the fresh outside air supplied by the ventilation device 1 will not pass through the refrigerant leak section in the coil device 20, so the refrigerant will not be mixed with the fresh outside air and supplied to the room. In other words, even if a refrigerant leak occurs, the ventilation and air conditioning system 100 according to Embodiment 1 can supply fresh outside air to the room, and the comfort level of the room is maintained.

[0025] The refrigerant detection sensor 22, which is a means for detecting refrigerant leaks, detects refrigerant leaks at a preset concentration below the standard value so that the concentration of refrigerant does not exceed the standard value between the time a refrigerant leak is detected and the time the shut-off valve 31 closes to shut off the refrigerant. For this reason, in the ventilation and air conditioning system 100 according to Embodiment 1, even if the refrigerant used is slightly flammable or flammable, refrigerant at a concentration exceeding the standard value will not accumulate inside the coil device 20 or in the room. In the ventilation and air conditioning system 100 according to Embodiment 1, the refrigerant detection sensor 22 is built into the coil device 20, but it is not necessarily required that the refrigerant detection sensor 22 be built into the coil device 20, and an externally installed refrigerant leak detection means may be used.

[0026] In the ventilation and air conditioning system 100 according to Embodiment 1, the ventilation device 1 is assumed to be a total heat exchange ventilation unit that has an integrated structure comprising an air supply passage equipped with an air supply fan 2 for taking in fresh outside air and an exhaust passage equipped with an exhaust fan 3 for blowing out indoor air. However, if only fresh outside air is to be taken in, the system may consist only of an air supply ventilation device including the air supply fan 2 in the air supply passage, or an air supply ventilation device including the air supply fan 2 and an exhaust ventilation device including the exhaust fan 3 may be provided separately, and the air supply and exhaust may be controlled separately. Furthermore, if the air supply passage is configured to allow air to pass through in the order of air supply fan 2, first damper device 10, and coil device 20, the air supply fan 2, first damper device 10, and coil device 20 may be housed in a single product.

[0027] Even when the ventilation device 1 is stopped, outside air may flow in through the duct depending on the pressure difference between the outdoors and indoors, or depending on the operating status of a local exhaust system installed separately from the ventilation and air conditioning system 100. Depending on the amount of outside air flowing in, the leaked refrigerant may be diluted and not reach a concentration that the refrigerant detection sensor 22 can detect, making it possible that the refrigerant leak cannot be detected. When the ventilation device 1 is stopped, even if there is no refrigerant leak, the airflow switching damper 11 switches to a position where it closes the second connection port 16 and opens the third connection port 17 to select the sub-airflow path 112 that directs air toward the fourth duct 43. This eliminates the difficulty in detecting leaked refrigerant due to the influence of outside air flowing in while the ventilation device 1 is stopped, and ensures reliable detection of refrigerant leaks.

[0028] In the ventilation and air conditioning system 100 according to this embodiment, the airflow switching damper 11 is switched to select the sub-airflow path 112 when refrigerant leaks. However, even in normal operating conditions when refrigerant is not leaking, if ventilation is performed without refrigerant flowing through the direct expansion coil 21, as in the fan mode, it is not necessary for the fresh outside air taken in to ventilate the coil device 20. For this reason, when ventilation is performed without refrigerant flowing through the direct expansion coil 21, the airflow switching damper 11 may be configured to select the sub-airflow path 112, which closes the second connection port 16 and opens the third connection port 17, similar to when refrigerant is leaking. By doing so, ventilation can be performed without ventilating the direct expansion coil 21, which has a large pressure loss within the coil device 20, thus reducing the load on the supply air blower 2 and enabling operation with less power consumption.

[0029] As described above, the ventilation and air conditioning system 100 according to Embodiment 1 provides a ventilation and air conditioning system 100 that, when refrigerant leaks from the coil device 20, changes the position of the airflow switching damper 11 of the first damper device 10, and supplies fresh outside air supplied from the ventilation device 1 to the room without being mixed with the leaked refrigerant. Furthermore, the ventilation and air conditioning system 100 according to Embodiment 1 can continue to supply fresh outside air to the room from the ventilation device 1 even if refrigerant leaks. Moreover, the ventilation and air conditioning system 100 according to Embodiment 1 also has the effect of being able to continue ventilating the room without stopping the supply of fresh air from outside, even if refrigerant leaks.

[0030] Embodiment 2. Figure 5 is a configuration diagram showing the state of the ventilation and air conditioning system according to Embodiment 2 during normal operation. Figure 6 is a configuration diagram showing the state of the ventilation and air conditioning system according to Embodiment 2 during refrigerant leakage. Figure 5 shows the positions of the airflow switching damper 11 and the second airflow switching damper 61 during normal operation. Figure 6 shows the positions of the airflow switching damper 11 and the second airflow switching damper 61 during refrigerant leakage. Furthermore, the airflow is indicated by arrows in Figures 5 and 6. The ventilation and air conditioning system 200 according to Embodiment 2 differs from the ventilation and air conditioning system 100 according to Embodiment 1 in that, as shown in Figures 5 and 6, the second damper device 60 is connected between the sixth duct 45 and the seventh duct 46, which are located downwind of the coil device 20. In the ventilation and air conditioning system 200 according to Embodiment 2, the duct connecting the coil device 20 and the second damper device 60 is the sixth duct 45, and the duct connecting the second damper device 60 and the first indoor air supply outlet 92 is the seventh duct 46.

[0031] The second damper device 60 has a fourth connection port 65 on its outer casing for connecting a seventh duct 46 connected to the first indoor air supply outlet 92, and a fifth connection port 66 for connecting a sixth duct 45 connected to the second ventilation port 27 of the coil device 20. Inside, it is equipped with a second airflow switching damper 61, which is a second airflow switching means. Fresh outside air supplied from the ventilation device 1 is supplied into the room through the second damper device 60.

[0032] The second damper device 60, like the first damper device 10, is connected to the control circuit unit 50 and the communication unit 52, and operates only by commands from the control circuit unit 50. The second damper device 60 also does not accept manual operation commands using the remote control 51.

[0033] If refrigerant leaks from the coil device 20, the airflow switching damper 11 of the first damper device 10 closes the second connection port 16 to which the second duct 41 connected to the coil device 20 is connected, and at the same time, the second airflow switching damper 61 of the second damper device 60 closes the fifth connection port 66 to which the sixth duct 45 connected to the coil device 20 is connected. Even if refrigerant leaks, the first damper device 10 can continue to supply air to the room, and the second damper device 60 can prevent the refrigerant from flowing out into the room.

[0034] The second airflow switching damper 61 of the second damper device 60 should be operated in synchronization with the airflow switching damper 11 of the first damper device 10. When refrigerant leakage is no longer detected and the abnormality is cleared, the second airflow switching damper 61 should be returned to its original position, as in Embodiment 1, and the fifth connection port 66 should be opened as shown in Figure 5.

[0035] The first damper device 10 and the second damper device 60 change the positions of the airflow switching damper 11 and the second airflow switching damper 61 when refrigerant leakage occurs. However, in operating modes that do not use the coil device 20, such as the fan mode, as in Embodiment 1, the airflow switching damper 11 and the second airflow switching damper 61 may be moved to the same positions as when refrigerant leakage occurs to prevent airflow to the coil device 20.

[0036] Furthermore, while the ventilation device 1 is stopped, the airflow switching damper 11 and the second airflow switching damper 61 may be set to the same position as when refrigerant is leaking, so that the refrigerant leaking from the coil device 20 can be reliably detected without diffusion. The difference between the first damper device 10 and the second damper device 60 is the presence or absence of the third connection port 17. The second damper device 60 only needs to be able to open and close the fifth connection port 66 to which the sixth duct 45 connected to the coil device 20 is connected, as shown in Figures 5 and 6.

[0037] As mentioned above, the first damper device 10 has a first duct 40 connected to the ventilation device 1 connected to the first connection port 15, a fourth duct 43 connected to the second indoor air supply outlet 95 connected to the second connection port 16, and a second duct 41 connected to the coil device 20 connected to the second connection port 16. Therefore, the airflow path switching damper 11 switches between an airflow path in which fresh outside air blown from the air supply outlet 7 of the ventilation device 1 is supplied to the room by passing through the coil device 20, and an airflow path in which the air is supplied directly to the room without passing through the coil device 20.

[0038] On the other hand, the second damper device 60 has a seventh duct 46 connected to the first indoor air supply outlet 92 connected to the fourth connection port 65, and a sixth duct 45 connected to the coil device 20 connected to the fifth connection port 66. The second airflow switching damper 61 switches between supplying the air vented through the coil device 20 to the room, or closing the fifth connection port 66 to which the coil device 20 is connected to shut off the refrigerant leaking from the coil device 20. As shown in Figure 5, the first damper device 10 is configured to vent from the first connection port 15 towards the second connection port 16, while the second damper device 60 is configured to vent from the fifth connection port 66 towards the fourth connection port 65, so the direction of ventilation is reversed. Here, "reverse airflow direction" means that the first damper device 10 is installed so that air flows out from the second connection port 16 to which the airflow switching damper 11 is provided, while the second damper device 60 is installed so that air flows in from the fifth connection port 66 to which the second airflow switching damper 61 is provided. Thus, the first damper device 10 is used to switch the airflow, and the second damper device 60 is used to open and close the fifth connection port 66 to which the coil device 20 is connected, so they are used for different purposes, but the first damper device 10 and the second damper device 60 can be the same device. In other words, the first damper device 10 can be used as the second damper device 60 by reversing the airflow direction.

[0039] According to the ventilation and air conditioning system 200 of Embodiment 2, by using the ventilation device 1, the first damper device 10, and the second damper device 60 in combination, ventilation by the ventilation device 1 can continue even if refrigerant leaks from the coil device 20, and the leaked refrigerant can be retained between the first damper device 10 and the second damper device 60, preventing the leaked refrigerant from flowing into the room.

[0040] Embodiment 3. Figure 7 is a configuration diagram showing the normal operation state of the ventilation and air conditioning system according to Embodiment 3. Figure 8 is a configuration diagram showing the state of the ventilation and air conditioning system according to Embodiment 3 when refrigerant leakage occurs. Figure 7 shows the positions of the supply airflow path switching damper 71 and the exhaust airflow path switching damper 72 during normal operation. Figure 8 shows the positions of the supply airflow path switching damper 71 and the exhaust airflow path switching damper 72 when refrigerant leakage occurs. Furthermore, the airflow is indicated by arrows in Figures 7 and 8. The ventilation and air conditioning system 300 according to Embodiment 3 differs from the ventilation and air conditioning system 100 according to Embodiment 1 in that the duct constituting the supply airflow path of the ventilation device 1 and the duct constituting the exhaust airflow path of the ventilation device 1 are connected to a single third damper device 70. The eighth duct 80 connects the ventilation device 1 and the third damper device 70. The ninth duct 81 connects the third damper device 70 and the coil device 20. The tenth duct 83 connects the third damper device 70 to the second indoor air supply outlet 95. The eleventh duct 84 connects the indoor exhaust inlet 93 to the third damper device 70. The twelfth duct 85 connects the third damper device 70 to the ventilation device 1.

[0041] The third damper device 70 is installed between the ventilation device 1 and the coil device 20, similar to the first damper device 10 shown in Embodiments 1 and 2. The third damper device 70 has an outer casing which is a sixth connection port 75 for connecting an eighth duct 80 connected to the supply air outlet 7 of the ventilation device 1, a seventh connection port 76 for connecting a ninth duct 81 connected to the second ventilation port 27 of the coil device 20, and an eighth connection port 77 for connecting a tenth duct 83 connected to the second indoor supply air outlet 95. Furthermore, the third damper device 70 has an outer casing which is a ninth connection port 78 for connecting an eleventh duct 84 connected to an indoor exhaust intake port 93, and a tenth connection port 79 for connecting a twelfth duct 85 connected to the exhaust intake port 8 of the ventilation device 1. The third damper device 70 includes a main supply air passage 711 connecting the sixth connection port 75 and the seventh connection port 76, a secondary supply air passage 712 connecting the sixth connection port 75 and the eighth connection port 77, and a supply air passage switching damper 71, which is an air passage switching means for switching between the main supply air passage 711 and the secondary supply air passage 712. Furthermore, the third damper device 70 includes a main exhaust air passage 721 connecting the ninth connection port 78 and the tenth connection port 79, a secondary exhaust air passage 722 connecting the seventh connection port 76 and the tenth connection port 79, an exhaust air passage switching damper 72, which is an exhaust air passage switching means for switching between the main exhaust air passage 721 and the secondary exhaust air passage 722, and a connecting air passage 74 connecting a part of the main supply air passage 711 and a part of the main exhaust air passage 721.

[0042] When this ventilation and air conditioning system is in normal operation, the supply airflow path switching damper 71 opens the seventh connection port 76 and closes the eighth connection port 77 so that air can be passed from the ventilation device 1 to the coil device 20. In this way, the ventilation and air conditioning system 300 according to Embodiment 3 selects the main supply airflow path 711 by switching the supply airflow path switching damper 71 during normal operation. The exhaust airflow path switching damper 72 opens the ninth connection port 78 and closes the communication airflow path 74 so that air drawn in from the indoor exhaust intake port 93 can be passed to the exhaust intake port 8 of the ventilation device 1. In this way, the ventilation and air conditioning system 300 according to Embodiment 3 selects the main exhaust airflow path 721 by switching the exhaust airflow path switching damper 72 during normal operation. Furthermore, in the ventilation and air conditioning system 300 according to Embodiment 3, the purpose of the supply airflow path switching damper 71 is to select the main supply airflow path 711 that supplies air to the coil device 20, and the purpose of the exhaust airflow path switching damper 72 is to select the main exhaust airflow path 721 that supplies air to the ventilation device 1, but at the same time, it also has the purpose of not mixing the supply air and exhaust air within the third damper device 70.

[0043] As shown in Figure 8, if refrigerant leaks, the ventilation and air conditioning system 300 according to Embodiment 3 switches the supply airflow path switching damper 71 to select the secondary supply airflow path 712, which supplies fresh outside air directly to the room without blowing air through the coil device 20. At this time, unlike the first damper device 10 shown in Embodiments 1 and 2, the supply airflow path switching damper 71 is not moved to a position that completely closes the seventh connection port 76, which is the outlet to the coil device 20. By not completely closing the seventh connection port 76, the ventilation and air conditioning system 300 according to Embodiment 3 can discharge the refrigerant that has leaked into the coil device 20 through the secondary exhaust airflow path 722 and out of the exhaust outlet 9 of the ventilation device 1. In other words, in the ventilation and air conditioning system 300 according to Embodiment 3, the supply airflow path switching damper 71 is used to separate the adjacent secondary supply airflow path 712 and the secondary exhaust airflow path 722, and serves the purpose of not mixing supply air and exhaust air within the third damper device 70.

[0044] The exhaust airflow switching damper 72 is switched to close the ninth connection port 78, which connects to the eleventh duct 84 connected to the indoor exhaust intake port 93, thereby selecting the secondary exhaust airflow path 722. At this time, the connecting airflow path 74, which connects a part of the main supply airflow path 711 and a part of the main exhaust airflow path 721 within the third damper device 70, is opened. As a result, the ninth duct 81 and the third duct 42, which normally serve as the supply airflow path via the coil device 20, now form a refrigerant discharge airflow path with the twelfth duct 85, which is connected to the exhaust intake port 8 of the ventilation device 1. In this way, the secondary exhaust airflow path 722 is used as a refrigerant discharge airflow path.

[0045] Refrigerant leaking into the coil device 20 is discharged outdoors by the refrigerant exhaust air passage and the exhaust fan 3. Even if refrigerant leaks, ventilation operation by the ventilation device 1 continues continuously, so unlike the embodiments of Embodiments 1 and 2, the leaked refrigerant does not accumulate in the coil device 20 but is discharged outdoors. In Embodiments 1 and 2 as well, the area where leaked refrigerant accumulates is limited to the coil device 20, but in the ventilation and air conditioning system 300 according to Embodiment 3, it is possible to eliminate the area where refrigerant accumulates. Furthermore, the ventilation and air conditioning system 300 according to Embodiment 3 also has the secondary effect that when repairing or replacing the coil device 20, there is no need to consider how to deal with leaked refrigerant before starting work, since there is no refrigerant accumulated in the coil device 20.

[0046] In the ventilation and air conditioning system 300 according to Embodiment 3, it is necessary to operate the supply air blower 2 and the exhaust air blower 3 simultaneously in the event of a refrigerant leak. For this reason, Figures 7 and 8 show a configuration using a ventilation device 1 that has a supply air blower 2 and an exhaust air blower 3 in a single casing 5. However, the ventilation and air conditioning system 300 may also be configured to have the supply air blower 2 and the exhaust air blower 3 as separate units, allowing the supply air and exhaust air to be operated individually.

[0047] In the ventilation and air conditioning system 300 according to Embodiment 3, when the coil device 20 is not used in a fan mode and when the ventilation and air conditioning system is stopped, the positions of the supply airflow path switching damper 71 and the exhaust airflow path switching damper 72 may be the same as the positions when refrigerant is leaking, and when the direct expansion coil 21 is not in use, it may be set to the outdoor side, which is the same as the ventilation direction when refrigerant is leaking.

[0048] Figure 9 is a configuration diagram showing the state of exhaust from two exhaust air passages of the ventilation and air conditioning system according to Embodiment 3. As shown in Figure 9, the opening degree of the exhaust air passage switching damper 72 may be adjusted so as not to completely close the ninth connection port 78 in the event of a refrigerant leak. By doing so, exhaust can be performed from both the main exhaust air passage 721 and the sub-exhaust air passage 722, making it possible to simultaneously discharge the refrigerant leaked into the coil device 20 and exhaust air from the room. The ventilation and air conditioning system 300 according to Embodiment 3 has the effect of quickly lowering the refrigerant concentration in the room because it is possible to exhaust air from the room even if refrigerant leaks into the room. Furthermore, the ventilation and air conditioning system 300 according to Embodiment 3 is useful not only in the event of a refrigerant leak, but also when it is desired to increase the amount of exhaust from the room. In the ventilation and air conditioning system 300 according to Embodiment 3, the ratio of the amount of exhaust from the main exhaust air passage 721 to the amount of exhaust from the sub-exhaust air passage 722 when increasing the amount of exhaust from the room can be arbitrarily set by adjusting the opening degree of the exhaust air passage switching damper 72.

[0049] As described above, according to the ventilation and air conditioning system 300 of Embodiment 3, since the supply air passage and the exhaust air passage are connected to a single third damper device 70, even if refrigerant leaks from the coil device 20, the ventilation operation of the ventilation device 1 that supplies fresh outside air can be continued, and the leaked refrigerant can be discharged outdoors without accumulating, providing a ventilation and air conditioning system 300.

[0050] The configurations shown in the above embodiments are merely examples of the content, and can be combined with other known technologies. It is also possible to omit or modify parts of the configuration without departing from the gist of the invention. [Explanation of Symbols]

[0051] 1 Ventilation system, 2 Supply air blower, 3 Exhaust air blower, 4 Total heat exchanger, 5 Casing, 6 Supply air intake, 7 Supply air outlet, 8 Exhaust air intake, 9 Exhaust air outlet, 10 First damper device, 11 Airflow switching damper, 15 First connection port, 16 Second connection port, 17 Third connection port, 20 Coil device, 21 Direct expansion coil, 22 Refrigerant detection sensor, 26 First ventilation port, 27 Second ventilation port, 30 Shut-off valve device, 31 Shut-off valve, 40 First duct, 41 Second duct, 42 Third duct, 43 Fourth duct, 44 Fifth duct, 45 Sixth duct, 46 Seventh duct, 50 Control circuit unit, 51 Remote control, 52 Communication unit, 60 Second damper device, 61 Second airflow switching damper, 65 66 Fourth connection port, 70 Fifth connection port, 71 Third damper device, 71 Intake airflow switching damper, 72 Exhaust airflow switching damper, 74 Connecting airflow, 75 Sixth connection port, 76 Seventh connection port, 77 Eighth connection port, 78 Ninth connection port, 79 Tenth connection port, 80 Eighth duct, 81 Ninth duct, 83 Tenth duct, 84 Eleventh duct, 85 Twelfth duct, 91 Outdoor intake air port, 92 First indoor intake air outlet, 93 Indoor exhaust intake port, 94 Outdoor exhaust outlet, 95 Second indoor intake air outlet, 100, 200, 300 Ventilation and air conditioning system, 111 Main airflow path, 112 Secondary airflow path, 711 Main intake airflow path, 712 Secondary intake airflow path, 721 Main exhaust airflow path, 722 Secondary exhaust airflow path.

Claims

1. A ventilation device comprising: an air intake port for drawing in outdoor air; an air outlet for blowing the air drawn in from the air intake port into the room; an air supply passage connecting the air intake port and the air supply passage; and an air supply fan provided in the air supply passage. A first damper device having: a first connection port into which air blown out from the ventilation device flows; a second and third connection ports for discharging the air that has flowed into the first connection port; a main air passage connecting the first connection port and the second connection port; a secondary air passage connecting the first connection port and the third connection port; and an air passage switching means for switching between the main air passage and the secondary air passage. A coil device having a first vent into which air flows from the first damper device, a second vent for releasing the air that has flowed into the first vent, and a heat exchange means provided in an air passage connecting the first vent and the second vent, which adjusts the temperature by exchanging heat between the air flowing in from the first vent and the refrigerant. A first duct connecting the air supply outlet of the ventilation device and the first connection port of the first damper device, A second duct connecting the second connection port of the first damper device and the first ventilation port of the coil device, A third duct connecting the second ventilation port of the coil device and the first indoor air supply outlet provided in the room, A fourth duct connecting the third connection port of the first damper device and the second indoor air supply outlet provided in the room, A refrigerant leak detection means for detecting leakage of the refrigerant from the heat exchange means, A control circuit unit that controls the ventilation device, the first damper device, and the coil device based on the detection state of the refrigerant leak detection means, Equipped with, The ventilation and air conditioning system is characterized in that, when the coil device is stopped, the control circuit unit switches the airflow switching means of the first damper device to select the secondary airflow path, regardless of whether or not the refrigerant leak detection means has detected a refrigerant leak, thereby reducing the load on the supply air blower by supplying outdoor air to the room without blowing it through the coil device.

2. The second damper device further comprises a fourth connection port provided in the middle of the third duct and connected to the third duct on the second ventilation port side of the coil device, a fifth connection port connected to the third duct on the first indoor air supply outlet side, and a second airflow switching means for opening and closing the fourth connection port, The ventilation and air conditioning system according to claim 1, characterized in that, when the coil device is stopped, the control circuit unit switches the airflow switching means of the first damper device to select the secondary airflow path and switches the second airflow switching means of the second damper device to close the fourth connection port, thereby reducing the load on the supply air blower by supplying outdoor air to the room without blowing it through the coil device.

3. An air intake port for drawing in outdoor air, an air outlet for blowing the air drawn in from the air intake port into the room, an air supply passage connecting the air intake port and the air supply outlet, and an air supply fan provided in the air supply passage, A ventilation device comprising: an exhaust intake port for drawing in indoor air; an exhaust outlet for blowing the air drawn in from the exhaust intake port to the outside; an exhaust air passage connecting the exhaust intake port and the exhaust outlet; and an exhaust fan provided in the exhaust air passage. The ventilation system includes a sixth connection port into which air blown out from the air supply outlet flows, seventh and eighth connection ports for discharging the air that has flowed into the sixth connection port, a ninth connection port into which air drawn in from the indoor exhaust intake flows, a tenth connection port for discharging the air that has flowed into the ninth connection port, a main air supply passage connecting the sixth and seventh connection ports, a secondary air supply passage connecting the sixth and eighth connection ports, and the main air supply passage and the front A third damper device having: an air intake airflow path switching means for switching between the main air intake airflow path and the secondary air intake airflow path; a main exhaust airflow path connecting the ninth connection port and the tenth connection port; a connecting airflow path provided between the main air intake airflow path and the main exhaust airflow path for connecting a part of the main air intake airflow path and a part of the main exhaust airflow path; a secondary exhaust airflow path connecting the seventh connection port and the tenth connection port via the connecting airflow path; and an exhaust airflow path switching means for switching between the main exhaust airflow path and the secondary exhaust airflow path. A coil device having a first vent into which air flows from the third damper device, a second vent for releasing the air that has flowed into the first vent, and a heat exchange means provided in an air passage connecting the first vent and the second vent, for adjusting the temperature by exchanging heat between the air flowing in from the first vent and the refrigerant. An eighth duct connecting the air supply outlet of the ventilation device and the sixth connection port of the third damper device, A ninth duct connecting the seventh connection port of the third damper device and the first ventilation port of the coil device, A third duct connecting the second ventilation port of the coil device and the first indoor air supply outlet provided in the room, A tenth duct connecting the eighth connection port of the third damper device to the second indoor air supply outlet provided in the room, An eleventh duct connecting the indoor exhaust intake port provided in the room and the ninth connection port of the third damper device, A twelfth duct connecting the tenth connection port of the third damper device and the exhaust intake port of the ventilation device, A refrigerant leak detection means for detecting leakage of the refrigerant from the heat exchange means, A control circuit unit that controls the ventilation device, the third damper device, and the coil device based on the detection state of the refrigerant leak detection means, Equipped with, The control circuit unit is characterized in that, if the refrigerant leak detection means does not detect a refrigerant leak, it switches the supply air path switching means to select the main supply air path and switches the exhaust air path switching means to select the main exhaust air path, and if the refrigerant leak detection means detects a refrigerant leak, it switches the supply air path switching means to select the secondary supply air path and switches the exhaust air path switching means to select the secondary exhaust air path.

4. An air intake port for drawing in outdoor air, an air outlet for blowing the air drawn in from the air intake port into the room, an air supply passage connecting the air intake port and the air supply outlet, and an air supply fan provided in the air supply passage, A ventilation device comprising: an exhaust intake port for drawing in indoor air; an exhaust outlet for blowing the air drawn in from the exhaust intake port to the outside; an exhaust air passage connecting the exhaust intake port and the exhaust outlet; and an exhaust fan provided in the exhaust air passage. The ventilation system includes a sixth connection port into which air blown out from the air supply outlet flows, seventh and eighth connection ports for discharging the air that has flowed into the sixth connection port, a ninth connection port into which air drawn in from the indoor exhaust intake flows, a tenth connection port for discharging the air that has flowed into the ninth connection port, a main air supply passage connecting the sixth and seventh connection ports, a secondary air supply passage connecting the sixth and eighth connection ports, and the main air supply passage and the front A third damper device having: an air intake airflow path switching means for switching between the main air intake airflow path and the secondary air intake airflow path; a main exhaust airflow path connecting the ninth connection port and the tenth connection port; a connecting airflow path provided between the main air intake airflow path and the main exhaust airflow path for connecting a part of the main air intake airflow path and a part of the main exhaust airflow path; a secondary exhaust airflow path connecting the seventh connection port and the tenth connection port via the connecting airflow path; and an exhaust airflow path switching means for switching between the main exhaust airflow path and the secondary exhaust airflow path. A coil device having a first vent into which air flows from the third damper device, a second vent for releasing the air that has flowed into the first vent, and a heat exchange means provided in an air passage connecting the first vent and the second vent, for adjusting the temperature by exchanging heat between the air flowing in from the first vent and the refrigerant. An eighth duct connecting the air supply outlet of the ventilation device and the sixth connection port of the third damper device, A ninth duct connecting the seventh connection port of the third damper device and the first ventilation port of the coil device, A third duct connecting the second ventilation port of the coil device and the first indoor air supply outlet provided in the room, A tenth duct connecting the eighth connection port of the third damper device to the second indoor air supply outlet provided in the room, An eleventh duct connecting the indoor exhaust intake port provided in the room and the ninth connection port of the third damper device, A twelfth duct connecting the tenth connection port of the third damper device and the exhaust intake port of the ventilation device, A refrigerant leak detection means for detecting leakage of the refrigerant from the heat exchange means, A control circuit unit that controls the ventilation device, the third damper device, and the coil device based on the detection state of the refrigerant leak detection means, Equipped with, The ventilation and air conditioning system is characterized in that, when the refrigerant leak detection means detects a refrigerant leak, the control circuit unit adjusts the opening of the exhaust airflow switching means of the third damper device so as not to completely close the ninth connection port, thereby allowing air to circulate from both the main exhaust airflow path and the secondary exhaust airflow path.

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