Supply system

Abstract

To provide a supply system capable of preventing acidic condensed water from staying in a collecting duct and a blowing duct for a long time.SOLUTION: The supplying system 1 includes a plurality of combustion devices 10 configured to burn fuel to generate exhaust gas containing CO2, a collection duct 20 configured to collect the exhaust gas discharged from the plurality of combustion devices 10, an air blowing duct 30 configured to guide the exhaust gas discharged from the collection duct 20 to the cultivation room 2, and an air blower 40 disposed in the air blowing duct 30 and configured to send the exhaust gas into the cultivation room 2. The collection duct 20 is provided with a first drain port 25 for discharging condensed water generated in the collection duct 20 by condensation of water vapor contained in the exhaust gas. Further, in the blowing duct 30, a second drain port 315 for discharging condensed water generated in the first duct 310 by condensation of the water vapor is provided in the first duct 310 which is a duct portion between the collection duct 20 and the blower 40.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a supply system for supplying CO2 to a plant cultivation room to promote plant growth. [Background technology]

[0002] Conventionally, there is known a supply system that supplies CO2 to a greenhouse (cultivation room) for cultivating plants to promote plant growth. In this type of system, exhaust gas containing CO2 emitted from a combustion device is supplied into the greenhouse through a duct. A blower is disposed midway through the duct to send the exhaust gas into the greenhouse. An example of this type of system, a CO2 supply device, is described in Patent Document 1.

[0003] In large greenhouses, it may be necessary to supply large amounts of CO2. Therefore, it is possible to use multiple combustion devices in the supply system. In this case, the supply system may be configured to include a collecting duct that collects exhaust gases from the multiple combustion devices, and a blower duct that has a blower and leads to the inside of the greenhouse. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7199060 Summary of the Invention [Problem to be solved by the invention]

[0005] Exhaust gas discharged from multiple combustion devices contains water vapor. The exhaust gas introduced into the collecting duct is relatively hot, and the temperature is higher than the ambient temperature of the collecting duct. Therefore, the exhaust gas is cooled as it flows through the collecting duct, and the water vapor may condense to form condensed water. Furthermore, the temperature of the exhaust gas introduced from the collecting duct into the blower duct is lower than when it was introduced into the collecting duct, but higher than the ambient temperature of the blower duct. Therefore, the water vapor may condense to form condensed water while the exhaust gas flows through the blower duct to the blower.

[0006] Condensed water generated in the collecting duct and the air duct is acidic, and if this acidic condensed water remains in the collecting duct and the air duct for a long time, there is a concern that the acidic condensed water may cause various problems.

[0007] For example, there is a concern that the acidic condensed water may corrode the inside of the collecting duct and the blower duct. There is also a concern that the acidic condensed water may leak from the collecting duct into the combustion device, shortening the life of the neutralizer installed in the combustion device or corroding the inside of the combustion device. Furthermore, there is a concern that the acidic condensed water in the blower duct may enter the inside of the blower, causing corrosion of the inside of the blower.

[0008] In view of the above problem, an object of the present invention is to provide a supply system that can prevent acidic condensed water from remaining in the collecting duct and the air supply duct for a long period of time. [Means for solving the problem]

[0009] A supply system according to a main aspect of the present invention includes a plurality of combustion devices that combust fuel to produce exhaust gas containing CO2, a collecting duct that collects the exhaust gas discharged from the plurality of combustion devices, a blower duct that guides the exhaust gas discharged from the collecting duct to a cultivation chamber, and a blower disposed in the blower duct that sends the exhaust gas into the cultivation chamber. The collecting duct is provided with a first drainage outlet for discharging condensed water generated in the collecting duct due to condensation of water vapor contained in the exhaust gas. Furthermore, the blower duct is provided with a second drainage outlet in a duct section between the collecting duct and the blower for discharging condensed water generated in the duct section due to condensation of the water vapor.

[0010] According to the supply system of this aspect, acidic condensed water generated from exhaust gas in the collecting duct is discharged from the first drain outlet, and acidic condensed water generated from exhaust gas in the duct portion of the blower duct between the blower and the collecting duct is discharged from the second drain outlet, thereby preventing the acidic condensed water from remaining in the collecting duct and the blower duct for a long period of time. [Effects of the Invention]

[0011] As described above, the present invention can provide a supply system that can prevent acidic condensed water from remaining in the collecting duct and the air supply duct for a long period of time.

[0012] The effects and significance of the present invention will become more apparent from the following description of the embodiments, however, the embodiments shown below are merely examples of how the present invention can be implemented, and the present invention is not limited to the embodiments described below. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a diagram schematically illustrating the configuration of a supply system according to an embodiment. [Figure 2] FIG. 2 is a diagram schematically showing the internal configuration of the combustion device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0014] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. For convenience, the up-down direction, the left-right direction, and the front-rear direction are indicated in FIG.

[0015] FIG. 1 is a diagram schematically illustrating the configuration of a supply system 1. As shown in FIG.

[0016] The supply system 1 is a system that can individually or simultaneously perform heating by circulating a heat medium (water) to heat the cultivation room 2 and supplying CO2 (carbon dioxide) to plants such as agricultural crops in the cultivation room 2. The cultivation room 2 is a building for growing plants, such as a greenhouse. The supply system 1 supplies CO2 to the plants in the cultivation room 2, thereby promoting photosynthesis in the plants.

[0017] The supply system 1 includes a plurality of combustion devices 10, a collection duct 20, a blower duct 30, a blower 40, hot water pipes 51 and 52, a pump 61, a three-way valve 62, hot water pipes 71 and 72, and a cooling tower 80.

[0018] The collecting duct 20 and the blower 40 are installed at a higher position than the multiple combustion devices 10. The multiple combustion devices 10, the collecting duct 20, and the hot water pipes 51, 52, 71 are installed outdoors, outside the cultivation room 2. They may also be installed indoors, i.e., in a room separate from the cultivation room 2. The blower 40 is installed inside the cultivation room 2. The air duct 30 has a portion located outside the cultivation room 2 and a portion located inside the cultivation room 2. The hot water pipe 72 is mostly located inside the cultivation room 2.

[0019] The combustion device 10 is a combustion-type combustion appliance that burns fuel (gas) to produce exhaust gas containing CO2. The combustion device 10 uses heat generated by the combustion to warm water that flows through a hot water pipe 52 and enters the combustion device 10. The combustion device 10 is equipped with an exhaust pipe 11 that guides the exhaust gas to a collecting duct 20. The exhaust pipe 11 is L-shaped and extends upward from the housing of the combustion device 10, then extends rearward at the top. The upper end of the exhaust pipe 11 is connected to the collecting duct 20, and the exhaust gas discharged from the combustion device 10 is discharged into the collecting duct 20 via the exhaust pipe 11 and collected in the collecting duct 20. In this embodiment, five combustion devices 10 are arranged side by side in the left-right direction.

[0020] The collecting duct 20 is a cylindrical member having a passage 21 therein and is made of a corrosion-resistant material such as stainless steel (SUS). The collecting duct 20 has an L-shape in plan view, and the front surface of its bent portion 22 is open to the outside, forming a louver 23. The louver 23 is an opening formed in the collecting duct 20. The collecting duct 20 is formed with a duct portion 24 extending rightward from the bent portion 22, and the right end of the passage 21 in the duct portion 24 is closed to the outside. The rear end of the collecting duct 20 is connected to the air supply duct 30, and the passage 21 inside the collecting duct 20 and the passage inside the air supply duct 30 are connected at this connection position. The louver 23 may be fitted with a hood or mesh to prevent rain, debris, and the like from entering.

[0021] A first drain outlet 25 is provided on the bottom surface of the collecting duct 20. The first drain outlet 25 is located, for example, outside the area where multiple exhaust stacks 11 are connected, downstream of the area in the flow of exhaust gas, and near the louver 23. The bottom surface of the collecting duct 20 gently slopes toward the first drain outlet 25 so that the position of the first drain outlet 25 is at its lowest. A first drain pipe 91 is connected to the first drain outlet 25. The first drain pipe 91 extends downward from the first drain outlet 25 and is connected to a drain pipe 3 provided within the site where the cultivation room 2 is installed.

[0022] A drain trap may be provided midway along the first drain pipe 91. If the drain pipe 3 does not pass directly below the first drain outlet 25, the first drain pipe 91 is bent appropriately to connect to the drain pipe 3.

[0023] The air duct 30 extends from the rear end of the passage 21 of the collecting duct 20 and is introduced into the cultivation room 2. The air duct 30 guides the exhaust gas discharged from the collecting duct 20 into the cultivation room 2. The blower 40 is disposed in the air duct 30 and sends the exhaust gas into the cultivation room 2. The blower 40 includes a casing, a fan disposed in the casing, and a motor that rotates the fan.

[0024] The air duct 30 is formed of a corrosion-resistant material such as stainless steel (SUS), and includes a first duct 310 and a second duct 320. The first duct 310 is a long, cylindrical pipe that extends from the rear end of the collecting duct 20 into the cultivation chamber 2 and is connected to the intake port of the blower 40. The first duct 310 is a duct portion of the air duct 30 between the collecting duct 20 and the blower 40. The second duct 320 is a long, cylindrical pipe that extends from the outlet port of the blower 40 to near the plants being cultivated. The height position of the tip of the second duct 320 is adjusted depending on the type of plant, and may be close to or far from the bottom of the cultivation chamber 2. The tip of the second duct 320 may also extend in multiple branches.

[0025] The first duct 310 includes a first straight section 311 extending linearly backward from the rear end of the collecting duct 20, a second straight section 312 extending linearly from the tip of the first straight section 311 to the right, i.e., toward the cultivation chamber 2, and entering the cultivation chamber 2, a third straight section 313 extending linearly from the intake port of the blower 40 to the left, i.e., toward the second straight section 312, and a curved section 314 located between the second straight section 312 and the third straight section 313 and curved downward in an approximately U-shape. In other words, the first duct 310 does not extend linearly almost horizontally toward the cultivation chamber 2 and then connect to the blower 40 directly, but rather first curves downward in an approximately U-shape before connecting to the blower 40. The first straight portion 311, the second straight portion 312 and the third straight portion 313, that is, the portions of the first duct 310 other than the curved portion 314, are gently inclined downward toward the curved portion 314.

[0026] The air supply duct 30 has a second drain outlet 315 at the bottom of the curved portion 314 of the first duct 310. The bottom of the curved portion 314 is the lowest position of the second drain outlet 315. A second drain pipe 92 is connected to the second drain outlet 315. The second drain pipe 92 extends downward from the second drain outlet 315 and is connected to a drain pipe 4 provided within the site where the cultivation room 2 is installed.

[0027] A drain trap may be provided midway along the second drain pipe 92. If the drain pipe 4 does not pass directly below the second drain outlet 315, the second drain pipe 92 is bent appropriately to connect to the drain pipe 4.

[0028] The five combustion devices 10 are connected to the passage 21 of the collecting duct 20 on the opposite side of the blower 40 with respect to the louver 23. Specifically, the exhaust pipes 11 of the five combustion devices 10 are connected to the passage 21 from the front side of the duct portion 24, and the passages in the exhaust pipes 11 are connected to the passage 21 of the duct portion 24. The exhaust gas from each combustion device 10 flows toward the bent portion 22. At this time, when the blower 40 is operating, outside air is introduced through the louver 23 and mixed with the exhaust gas. The mixed gas is then sent into the cultivation room 2 via the collecting duct 20 and the blower duct 30. On the other hand, when the blower 40 is stopped, most of the exhaust gas in the collecting duct 20 does not move rearward at the bent portion 22 and is discharged from the louver 23.

[0029] The hot water pipe 51 is a pipe for transporting hot water from the combustion device 10 toward the cultivation room 2, and the hot water pipe 52 is a pipe for transporting hot water from the cultivation room 2 toward the combustion device 10. Branch pipes 51a are formed from the hot water pipe 51 toward each combustion device 10, and each branch pipe 51a is connected to the corresponding combustion device 10. Branch pipes 52a are formed from the hot water pipe 52 toward each combustion device 10, and each branch pipe 52a is connected to the corresponding combustion device 10. The end of the hot water pipe 52 opposite the combustion device 10 is connected to a cooling tower 80.

[0030] The pump 61 is installed in the hot water pipe 52 and transports the hot water in the hot water pipe 52 through the combustion device 10 and the hot water pipe 51 in the direction toward the cultivation room 2 and the cooling tower 80. When the pump 61 is driven, the hot water in the hot water pipe 52 is supplied to each combustion device 10 through each branch pipe 52a. When the pump 61 is stopped, the hot water in the hot water pipe 52 is no longer supplied to each combustion device 10.

[0031] The three-way valve 62 is connected to the hot water pipes 51, 71 and one end of the hot water pipe 72. The three-way valve 62 connects the hot water pipe 51 to either the hot water pipe 71 or the hot water pipe 72. The hot water pipe 71 is a pipe for connecting the three-way valve 62 to the cooling tower 80. The hot water pipe 72 is a pipe for supplying heat by hot water to the inside of the cultivation room 2. The other end of the hot water pipe 72 is connected to the hot water pipe 52.

[0032] When cooling the hot water in each hot water pipe, the hot water pipe 51 and the hot water pipe 71 are connected by a three-way valve 62. The cooling tower 80 cools the water from the hot water pipe 71 and sends the cooled water to the hot water pipe 52. This cools the hot water in the hot water pipe 51.

[0033] When hot water from each hot water pipe is sent to the cultivation room 2, the three-way valve 62 connects the hot water pipe 51 to one end of the hot water pipe 72. This allows the hot water from the hot water pipes 51 and 52 to circulate through the hot water pipe 72, heating the cultivation room 2.

[0034] FIG. 2 is a diagram schematically illustrating the internal configuration of the combustion device 10. As shown in FIG.

[0035] The combustion device 10 includes a housing 110, a boiler body 120, piping 131, a solenoid valve 132, a proportional valve 133, piping 141, a flow sensor 142, a hot water outlet valve 143, piping 144, a mixer 145, a bypass valve 146, a fan 150, and a circuit board 160.

[0036] The housing 110 forms the outer shell of the combustion device 10. Each part of the combustion device 10 is arranged inside the housing 110. The housing 110 is provided with an air inlet 111 for introducing outside air and an exhaust port 112 for exhausting exhaust gas generated in the can body 120. When the fan 150 is driven, the inside of the housing 110 becomes negative pressure, and therefore outside air is introduced into the housing 110 through the air inlet 111.

[0037] The boiler body 120 accommodates a combustor 121, a primary heat exchanger 122, and a secondary heat exchanger 123. Fuel gas is supplied to the combustor 121 through a pipe 131. The pipe 131 is provided with a solenoid valve 132 for opening and closing the pipe 131, and a proportional valve 133 for adjusting the amount of fuel gas supplied. The solenoid valve 132 and the proportional valve 133 are controlled by a control unit 161 on a circuit board 160.

[0038] The pipe 141 is connected to the primary heat exchanger 122 and the secondary heat exchanger 123. Water from the hot water pipe 52 is supplied to the inlet of the pipe 141 via the branch pipe 52a, and hot water is discharged from the outlet of the pipe 141 via the branch pipe 51a into the hot water pipe 51. The flow rate sensor 142 is installed near the inlet of the pipe 141 and detects the flow rate of water supplied to the inlet of the pipe 141. The control unit 161 of the circuit board 160 operates the combustion device 10 when the detection signal from the flow rate sensor 142 indicates that water is being supplied to the pipe 141. On the other hand, the control unit 161 stops the combustion device 10 when the detection signal from the flow rate sensor 142 indicates that water is not being supplied to the pipe 141.

[0039] While the water flowing through the pipe 141 passes through the passages of the primary heat exchanger 122 and the secondary heat exchanger 123, heat generated in the combustor 121 is transferred to the water via the primary heat exchanger 122 and the secondary heat exchanger 123. This warms the water in the pipe 141. The primary heat exchanger 122 is a sensible heat recovery type heat exchanger, and the secondary heat exchanger 123 is a latent heat recovery type heat exchanger. The passage portion of the primary heat exchanger 122 is made of copper, and the passage portion of the secondary heat exchanger 123 is made of stainless steel (SUS). The secondary heat exchanger 123 is provided on the exhaust port 112 side of the primary heat exchanger 122. The water flowing through the pipe 141 is warmed while passing through the secondary heat exchanger 123, and is then further warmed while passing through the primary heat exchanger 122.

[0040] The hot water outlet valve 143 is provided in the pipe 141 and is a valve for adjusting the amount of hot water discharged. The hot water outlet valve 143 is driven by a stepping motor. The stepping motor is controlled by a control unit 161 on the circuit board 160.

[0041] Pipe 144 connects the inlet side and outlet side of pipe 141, and one end of pipe 144 is connected to the outlet side of pipe 141 by mixer 145. Water from pipe 144 is mixed with the hot water flowing toward the outlet of pipe 141, thereby adjusting the temperature of the hot water discharged from the outlet of pipe 141. Bypass valve 146 is provided in pipe 144 and is a valve for adjusting the amount of water mixed in. Bypass valve 146 is driven by a stepping motor. The stepping motor is controlled by control unit 161 on circuit board 160.

[0042] The fan 150 is connected to the air intake port 120a of the can body 120. The exhaust port 120b of the can body 120 is connected to the exhaust stack 11 via the exhaust port 112 formed in the housing 110. The fan 150 is, for example, a single-phase fan. The fan 150 may also be a sirocco fan. The fan 150 supplies air for combustion into the can body 120 when the motor is driven. The fan 150 is controlled by a control unit 161 on a circuit board 160.

[0043] A control unit 161 and a circuit unit for driving the combustion device 10 are mounted on the circuit board 160. The control unit 161 is composed of, for example, a microcomputer and a memory that stores a control program for the microcomputer. The memory includes RAM, ROM, etc. The control unit 161 controls each part of the combustion device 10.

[0044] The combustion device 10 may be provided with a neutralizer that neutralizes acidic condensed water generated from the exhaust gas inside the boiler body 120.

[0045] The supply system 1 performs one of the following operations: CO2 supply / heating operation, CO2 supply operation, or heating operation. "CO2 supply / heating operation" is an operation in which both CO2 supply and heating are performed, "CO2 supply operation" is an operation in which only CO2 supply is performed, and "heating operation" is an operation in which only heating is performed.

[0046] In the CO2 supply / heating operation, the pump 61 and the blower 40 are operated. In addition, the three-way valve 62 connects the hot water pipe 51 to the hot water pipe 72.

[0047] When the pump 61 operates, water is supplied from the hot water pipe 52 to each combustion device 10. When the control unit 161 of each combustion device 10 detects via the flow sensor 142 that water has been supplied from the hot water pipe 52, it drives the combustor 121. This heats the water flowing through the pipe 141, and the hot water is released into the hot water pipe 51. The hot water released into the hot water pipe 51 circulates through the hot water pipe 72 arranged in the cultivation room 2, heating the interior of the cultivation room 2.

[0048] Furthermore, as the combustor 121 is driven, exhaust gas containing CO2 is discharged through the exhaust pipe 11 into the passage 21 and proceeds to the vicinity of the louver 23. At this time, since the blower 40 is operating, outside air is introduced through the louver 23 and mixed with the exhaust gas near the louver 23. The exhaust gas mixed with the outside air is then sent to the cultivation chamber 2 through the air duct 30 and supplied to the plants in the cultivation chamber 2.

[0049] During CO2 supply operation, the pump 61 and the blower 40 operate. In addition, the three-way valve 62 connects the hot water pipe 51 to the hot water pipe 71. Because hot water is not sent to the hot water pipe 72 extending into the cultivation room 2, the cultivation room 2 is not heated, and only exhaust gas is supplied into the cultivation room 2.

[0050] During heating operation, the pump 61 operates while the blower 40 is stopped. Also, the three-way valve 62 connects the hot water pipe 51 to the hot water pipe 72. In this case, hot water heated by each combustion device 10 circulates through the hot water pipe 72 extending into the cultivation room 2, thereby heating the cultivation room 2. When the combustor 121 is driven, exhaust gas containing CO2 is discharged into the passage 21 through the exhaust stack 11 and proceeds to the vicinity of the louver 23. At this time, because the blower 40 is stopped, most of the exhaust gas in the passage 21 is not sent to the rear of the collecting duct 20, but is discharged to the outside through the louver 23. As a result, exhaust gas is not supplied into the cultivation room 2.

[0051] In the supply system 1 of this embodiment, the exhaust gas discharged from the multiple combustion devices 10 contains water vapor. The exhaust gas introduced into the collecting duct 20 has a relatively high temperature, which is higher than the temperature around the collecting duct 20. Therefore, the exhaust gas is cooled while flowing through the collecting duct 20, and the water vapor may condense to form condensed water. Furthermore, the temperature of the exhaust gas introduced from the collecting duct 20 into the first duct 310 of the blower duct 30 is lower than the temperature at the time of introduction into the collecting duct 20, but is higher than the temperature around the first duct 310. Therefore, the water vapor may condense while the exhaust gas is flowing through the first duct 310, and condensed water may form.

[0052] For example, exhaust gas comes into contact with the inner wall surface of the collecting duct 20, is cooled, and condenses on the inner wall surface, thereby generating acidic condensed water within the collecting duct 20. Also, exhaust gas comes into contact with the inner wall surface of the first duct 310, is cooled, and condenses on the inner wall surface, thereby generating acidic condensed water within the first duct 310. Furthermore, the exhaust gas is also cooled by being mixed with outside air introduced through the louver 23 within the collecting duct 20. This can also be a factor in the generation of condensed water within the collecting duct 20 and the first duct 310.

[0053] Condensed water generated in the collecting duct 20 and the first duct 310 is acidic. The acidic condensed water generated in the collecting duct 20 flows along the bottom surface of the collecting duct 20, collects near the first drain outlet 25, and is discharged from the first drain outlet 25. The condensed water then passes through the first drain pipe 91 and is discharged into the drain pipe 3. Furthermore, the acidic condensed water generated in the first duct 310 flows along the bottom of the first duct 310, collects at the bottom of the curved portion 314, and is discharged from the second drain outlet 315. The condensed water then passes through the second drain pipe 92 and is discharged into the drain pipe 4. This makes it less likely that the acidic condensed water will remain in the collecting duct 20 and the first duct 310 of the air supply duct 30 for a long period of time.

[0054] In the collecting duct 20, the first drain outlet 25 is provided at a position downstream of and away from the area where the multiple exhaust stacks 11 are connected. Therefore, even if dust or other foreign matter clogs the first drain outlet 25, making it difficult for condensed water to be discharged from the first drain outlet 25, the condensed water is unlikely to accumulate in the area where the multiple exhaust stacks 11 are connected, and the condensed water is unlikely to enter each combustion device 10 through each exhaust stack 11. In addition, because the first drain outlet 25 is close to the louver 23, maintenance such as cleaning can be easily performed on the first drain outlet 25 through the louver 23.

[0055] In first duct 310 of blower duct 30, second drain outlet 315 is provided at the bottom of curved portion 314. This makes it easy to collect condensed water generated inside first duct 310, which is a long pipe, in one place and discharge it from second drain outlet 315. Furthermore, even if foreign matter such as dust clogs second drain outlet 315 and makes it difficult for the condensed water to be discharged from second drain outlet 315, the condensed water can be collected in curved portion 314, making it less likely for the condensed water to flow toward blower 40.

[0056] In the second duct 320 downstream of the blower 40, the temperature difference between the exhaust gas and the cultivation chamber 2 is small because the exhaust gas has been cooled by the first duct 310. Furthermore, the amount of water vapor in the exhaust gas is small because the exhaust gas has been condensed in the first duct 310. In particular, the first duct 310 has a curved portion 314, which allows the length of the first duct 310 to be increased even if the distance between the collecting duct 20 and the blower 40 is not long. Therefore, the amount of heat exchange between the first duct 310 and the exhaust gas is large, which makes it easy for the temperature of the exhaust gas to drop and condensation to occur. Therefore, in the second duct 320, the temperature difference is small and the amount of water vapor is likely to decrease. This makes it difficult for acidic condensation to occur in the second duct 320.

[0057] Furthermore, the amount of water vapor in the exhaust gas discharged into the cultivation room 2 from the air supply duct 30, i.e., the second duct 320, is also reduced. This makes it less likely that acidic condensed water will be generated in the cultivation room 2.

[0058] <Effects of the embodiment> According to this embodiment, the following effects are achieved.

[0059] In the supply system 1, the collecting duct 20 is provided with a first drain outlet 25 for discharging condensed water generated in the collecting duct 20 due to condensation of water vapor contained in the exhaust gas, and the blower duct 30 is provided with a second drain outlet 315 in the first duct 310 (duct portion) between the collecting duct 20 and the blower 40 for discharging condensed water generated in the first duct 310 due to condensation of water vapor.

[0060] According to this configuration, acidic condensed water generated from exhaust gas in the collecting duct 20 is discharged from the first drain outlet 25, and acidic condensed water generated from exhaust gas in the first duct 310 is discharged from the second drain outlet 315. This prevents the acidic condensed water from remaining in the collecting duct 20 and the first duct 310 for a long period of time.

[0061] This prevents the supply system 1 from malfunctioning due to acidic condensed water. For example, the inside of the collecting duct 20 and the first duct 310 is less likely to corrode due to acidic condensed water. Also, it is possible to prevent the acidic condensed water from leaking from the collecting duct 20 to the combustion device 10, which would shorten the life of the neutralizer provided in the combustion device 10 or corrode the inside of the combustion device 10. Furthermore, it is possible to prevent the acidic condensed water in the first duct 310 from entering the inside of the blower 40, which would corrode the inside of the blower 40.

[0062] Furthermore, the first duct 310 includes a curved portion 314 that curves downward, and the second drain port 315 is provided at the bottom of the curved portion 314.

[0063] This configuration allows condensed water generated in the first duct 310 to be collected in one place and easily discharged from the second drain outlet 315. Furthermore, since the length of the first duct 310 is longer, the amount of heat exchange between the first duct 310 and the exhaust gas increases, making it easier for water vapor in the exhaust gas to condense and decrease as it flows through the first duct 310. As a result, less water vapor is discharged from the air supply duct 30 into the cultivation chamber 2, making it less likely for acidic condensed water to be generated in the cultivation chamber 2 and reducing the likelihood of problems such as corrosion occurring within the cultivation chamber 2.

[0064] <Example of change> The supply system 1 according to the present invention is not limited to the configuration of the above embodiment, and various modifications are possible.

[0065] In the above embodiment, the curved portion 314 of the first duct 310 in the air supply duct 30 is located inside the cultivation room 2, but it may be located outside the cultivation room 2. In addition, the curved portion 314 and the second drain outlet 315 may be provided at multiple locations on the first duct 310.

[0066] Furthermore, the first duct 310 may be provided with a curved portion that is curved in a substantially U-shape in the horizontal direction (forward or backward in the configuration of FIG. 1) in addition to the curved portion 314. This allows the length of the first duct 310 to be further increased even if the distance between the collecting duct 20 and the blower 40 cannot be made long.

[0067] In the above embodiment, the exhaust stack 11 of each combustion device 10 is connected to the passage 21 from the front side of the duct portion 24 of the collecting duct 20, but it may also be connected to the passage 21 from a side other than the front side of the duct portion 24.

[0068] In the above embodiment, the collecting duct 20 is a cylindrical member having an L-shape in a plan view. However, the collecting duct 20 may be a member of any shape as long as it can collect exhaust gases discharged from the multiple combustion devices 10.

[0069] In the above embodiment, the first drain outlet 25 is located outside the area where the multiple exhaust stacks 11 are connected, downstream of the area, and near the louver 23. However, the first drain outlet 25 may be provided in any position as long as it can discharge condensed water generated in the collecting duct 20. For example, the first drain outlet 25 may be provided in any position on the bottom surface of the collecting duct 20, or in any position on the lower ends of the front, rear, left, and right sides of the collecting duct 20.

[0070] In the above embodiment, the first duct 310 of the blower duct 30 includes a curved portion 314 that curves downward, and the second drain outlet 315 is provided at the bottom of the curved portion 314. However, the first duct 310 may not be provided with the curved portion 314, and an arbitrary position of the first duct 310 may be made the lowest, and the second drain outlet 315 may be provided at this lowest position. For example, the first duct 310 may be configured to slope downward from the blower 40 side to the collecting duct 20 side, and the second drain outlet 315 may be provided at the end of the first duct 310 on the collecting duct 20 side.

[0071] In the above embodiment, a neutralizer for neutralizing acidic condensed water may be provided in the first drain pipe 91 and the second drain pipe 92. If the first drain pipe 91 and the second drain pipe 92 do not have a neutralizer, the drain pipes 91, 92 will be connected to the drain pipes 3, 4 of the sewage system, but if the first drain pipe 91 and the second drain pipe 92 have a neutralizer, the drain pipes 91, 92 can be connected to the drain pipes 3, 4 of the stormwater system.

[0072] In the above embodiment, five combustion devices 10 are connected to the passage 21, but other numbers of combustion devices 10 may be connected.

[0073] In the above embodiment, the collecting duct 20 and the first duct 310 of the air duct 30 may be integrally formed.

[0074] In the above embodiment, water is used as a heat medium for heating the inside of the cultivation room 2, but this is not limiting, and liquids other than water (for example, antifreeze liquid) or gas may also be used.

[0075] In the above embodiment, the fuel used to cause combustion in the combustion device 10 is fuel gas, but the fuel is not limited to this and may be other fuels such as fuel oil.

[0076] In the above embodiment, the configuration of the combustion device 10 is not limited to the configuration shown in FIG. 2, and can be modified as appropriate.

[0077] In addition, the embodiments of the present invention can be modified in various ways as appropriate within the scope of the claims. [Explanation of symbols]

[0078] 1. Supply System 2 Cultivation room 10 Combustion equipment 20 Collecting duct 25 1st drain 30 Ventilation duct 40 Blower 310 First Duct (Duct Part) 314 Curved section 315 Drainage Outlet No. 2

Claims

1. Combustion of fuel produces CO ２ a plurality of combustion devices producing exhaust gases including a collecting duct for collecting the exhaust gases discharged from the plurality of combustion devices; a ventilation duct that guides the exhaust gas discharged from the collecting duct into a cultivation room; a blower disposed in the air duct to send the exhaust gas into the cultivation room; The collecting duct is provided with a first drain port for discharging condensed water generated in the collecting duct by condensation of water vapor contained in the exhaust gas, The air blower duct is provided with a second drain port in a duct portion between the collecting duct and the blower, for discharging condensed water generated in the duct portion by condensation of the water vapor. A supply system comprising:

2. 2. The delivery system of claim 1, the duct portion includes a curved portion that curves downward, The second drain port is provided at the bottom of the curved portion. A supply system comprising:

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