JP2015204787A - plant factory - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cool nutritious liquid after heating sterilization to a normal temperature level without increasing power consumption, and prevent the inside of a cultivation room from becoming unnecessarily highly humid without making an air conditioner perform a reheating dehumidifying operation.SOLUTION: Cultivation containers (11), illumination devices and an air conditioner (20) are installed in a cultivation room (3) of a plant factory (1), and a nutritious liquid circulating system (30) is provided which supplies nutritious liquid to plants (15) housed in the cultivation containers (11) and recovers residual nutritious liquid to supply again to the plants. A heating sterilizer (46) which heats to sterilize the recovered nutritious liquid is disposed on a circulation path (33) that returns the recovered nutritious liquid to a supply side. Furthermore, the circulation path (33) on a subsequent stage of the heating sterilizer (46) is extended to the cultivation room (3), and a radiator (47) is provided at a portion extended to the cultivation room (3).

Description

  The present invention relates to a plant factory provided with a lighting device, an air conditioner, and a nutrient solution circulation system.

  Conventionally, in a hydroponics plant factory or the like, a plurality of cultivation containers are arranged at predetermined intervals in a vertical direction in a cultivation room of a building. The cultivation container accommodates a cultivation floor, and plants are planted on the cultivation floor. The nutrient solution supply to the plurality of cultivation containers is performed by a nutrient solution circulation system. The nutrient solution circulation system is configured to supply the nutrient solution stored in the nutrient solution tank, collect excess nutrient solution discharged from each cultivation container, and return it to the nutrient solution tank.

  Some of such nutrient solution circulation systems include a sterilizer and are configured to sterilize the collected nutrient solution and then return it to the nutrient solution tank. This is because the collected nutrient solution contains pathogenic bacteria such as Fusarium bacteria (a type of mold) and bacterial wilt. If the collected nutrient solution is reused without being sterilized, pathogenic bacteria grow to cause disease in the plant or cause the plant to die.

  As a method for sterilizing pathogenic bacteria, there are sterilization by ultraviolet rays and ozone, but sterilization by heating is also effective and effective. However, in the case of heat sterilization, it is necessary to cool the nutrient solution after sterilization to a normal temperature level. This is because if the nutrient solution is returned to the nutrient solution tank with insufficient cooling, the temperature in the nutrient solution tank rises, and mold or the like is generated in the nutrient solution tank. Although the nutrient solution to be reused has been sterilized, the pipes and nutrient tanks through which the nutrient solution flows are not aseptic. Therefore, mold, bacteria, etc. inevitably grow as the temperature of the nutrient solution rises.

  Conventionally, a heat exchanger for exchanging heat between the nutrient solution sent to the heat sterilizer and the nutrient solution passed through the heat sterilizer is provided to cool the heat sterilized nutrient solution. According to this, the nutrient solution after heating is cooled, preheating the nutrient solution before heating and improving the heating efficiency by the heat sterilizer. In Patent Documents 1 and 2, a heat pump is used as a heating means, and the nutrient solution is heated at the high temperature portion of the heat pump cycle to sterilize pathogenic bacteria, while in addition to cooling in the heat exchanger, the low temperature of the heat pump cycle The structure which cools a nutrient solution further in a part and lowers to a normal temperature level is disclosed.

  In general, a lighting room and an air conditioner are also installed in the cultivation room. An illuminating device irradiates artificial light with respect to the plant accommodated in the cultivation container. By controlling lighting of the lighting device, a day and night environment suitable for plant growth is artificially created.

  Moreover, an air conditioner suppresses the temperature rise in the cultivation room by the heat | fever emitted from an illuminating device by air_conditionaing | cooling operation, and adjusts humidity in the cultivation room. Since a large amount of water vapor is generated from the plant by transpiration, the cultivation room tends to be more humid than necessary. Therefore, conventionally, humidity has been adjusted in the cultivation room to maintain the humidity (relative humidity) within a certain range suitable for plant growth.

JP 2004-216104 A (released on August 5, 2004) Japanese Patent Laying-Open No. 2005-164111 (released on June 23, 2005)

  However, using the conventional techniques described in Patent Documents 1 and 2, when trying to cool the nutrient solution after heat sterilization to a normal temperature level, the power consumption used in the heat pump cycle increases and the running cost increases. There's a problem.

  That is, in order to cool the nutrient solution after heat sterilization to the normal temperature level in the low temperature part of the heat pump cycle, the low temperature part needs to be lower than the normal temperature. Therefore, it is necessary to ensure a large temperature difference between the high temperature part and the low temperature part in the heat pump cycle, and power consumption used in the heat pump cycle is increased.

  In addition, in the configuration in which the humidity in the cultivation room is maintained at a value within a certain range by humidity adjustment by the air conditioner, reheat dehumidification operation is required instead of dehumidification by normal cooling operation. There is a problem that power consumption increases and running cost increases.

  In other words, during the daytime period (light period) when the lighting device is lit, the temperature in the cultivation room rises due to the heat generated from the lighting device, so that the air conditioner operates in a timely manner and suppresses the increase in the room temperature while dehumidifying To maintain proper humidity. On the other hand, during the night period (dark period) when the lighting device is turned off, heat is not emitted from the lighting device, so the air conditioner operates continuously until it reaches the set temperature, but then continues It will not work. When the air conditioner is not continuously operated, a time zone in which dehumidification is not performed occurs, and thus the humidity increases excessively. Therefore, the air conditioner is equipped with a reheat dehumidifying operation in which the air is once cooled to a temperature lower than the set temperature for the night period and forcibly dehumidified, and then the air is warmed to the set temperature for the night period and sent out. There is also a way to let them do. However, since the reheat dehumidifying operation requires energy for warming the air cooled to a temperature lower than the set temperature (for reheating), the power consumption is larger than that in the normal cooling operation. End up.

  The present invention has been made in view of such problems, and its purpose is to cool the nutrient solution after sterilization to a normal temperature level without increasing the power consumption of the plant factory, and the power consumption is large. An object of the present invention is to provide a plant factory that can prevent the cultivation room from becoming unnecessarily high humidity without causing the air conditioner to perform reheat dehumidification operation.

  In order to solve the above-described problem, a plant factory according to one embodiment of the present invention includes a cultivation container, a lighting device, and an air conditioner disposed in a cultivation room for cultivating a plant, and is accommodated in the cultivation container. A nutrient solution circulation system is provided for supplying nutrient solution to the plant, collecting the remaining nutrient solution, and supplying it again. The collected nutrient solution in the nutrient solution circulation system for returning the collected nutrient solution to the supply side is provided. In a plant factory provided with a heat sterilizer for heat sterilizing the liquid, a circulation path downstream from the heat sterilizer extends to the cultivation room, and a radiator is provided to the part extended to the cultivation room. It is characterized by being provided.

  According to one aspect of the present invention, the nutrient solution after sterilization can be cooled to a normal temperature level without increasing the power consumption of the plant factory, and the reheat dehumidification operation with high power consumption is performed on the air conditioner. There is an effect that it is possible to provide a plant factory that prevents the cultivation room from becoming unnecessarily high humidity without causing it to grow.

It is a schematic diagram which shows the structure of the plant factory which concerns on one Embodiment of this invention. It is a graph which shows transition of the temperature and humidity in a cultivation room at the time of adjusting humidity using the heat radiation from an air conditioner and a heat radiator. It is a graph which shows transition of the temperature and humidity in a cultivation room at the time of adjusting humidity only with an air conditioner. It is a schematic diagram which shows the structure of the plant factory which concerns on the other form of implementation of this invention. It is a schematic diagram which shows the structure of the plant factory which concerns on the other form of implementation of this invention.

[Embodiment 1]
Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a schematic diagram illustrating a configuration of a plant factory 1 according to an embodiment of the present invention. As shown in FIG. 1, a cultivation room 3 for growing plants is provided in a building 2 of a plant factory 1. Next to the cultivation room 3, a tank room 4 for producing and storing a nutrient solution to be supplied to the plant is provided.

  The plant factory 1 is a fully-controlled plant factory that produces plants 15 such as vegetables and fruits in a completely controlled environment in a closed space separated from the outside. Therefore, at least the cultivation room 3 is configured as a closed space in which heat insulating properties and light shielding properties are ensured.

  A plurality of cultivation shelves 10 are installed at predetermined intervals in the cultivation room 3. The plurality of cultivation shelves 10 all have the same configuration. The cultivation shelf 10 includes a plurality of cultivation containers 11 arranged at intervals in the vertical direction and a rack 12 that supports the plurality of cultivation containers 11. Each cultivation container 11 accommodates a cultivation floor 13 made of, for example, a styrene plate, and a plant 15 is planted on the cultivation floor 13. A nutrient solution supply path 31 of a nutrient solution circulation system 30 extending from the tank chamber 4 is connected to each cultivation container 11 in each cultivation shelf 10 through a channel (not shown), and the nutrient solution is supplied from the nutrient solution tank 40. It is comprised so that. Each cultivation container 11 is connected to a nutrient solution recovery path 32 of a nutrient solution circulation system 30 extending from the tank chamber 4 so that the excess nutrient solution discharged from each cultivation shelf 10 is collected. Has been.

  Furthermore, a plurality of lighting devices (not shown) and an air conditioner (air conditioner) 20 are disposed in the cultivation room 3. The lighting device is installed, for example, on the rack 12 of the cultivation shelf 10 so that artificial light can be irradiated from above the plant 15. The illumination device is composed of, for example, an LED or a fluorescent lamp.

  The air conditioner 20 is arranged along the ceiling or wall in the cultivation room 3. The air conditioner 20 performs a cooling operation, cools the air in the cultivation room 3 with the cooler 21 and dehumidifies it, and blows out the air cooled and dehumidified with the fan 22 from the air outlet 23 in the cultivation room 3. Return to. The air conditioner 20 suppresses a temperature rise in the cultivation room 3 due to heat generated from the lighting device during the cooling operation, and maintains the humidity in the cultivation room 3 within a certain range suitable for the growth of the plant 15. Dehumidify as required (humidity control).

  The nutrient solution circulation system 30 supplies nutrient solution from the nutrient solution tank 40 to each cultivation shelf 10, collects excess nutrient solution discharged from each cultivation shelf 10, and returns it to the nutrient solution tank 40. The heat sterilizer 46 is disposed in the nutrient solution return path 33 for returning the collected nutrient solution to the nutrient tank 40.

  As shown in FIG. 1, the nutrient solution circulation system 30 includes a nutrient solution supply path 31 extending from the nutrient solution tank 40 to each cultivation shelf 10 in the cultivation room 3, and from each cultivation shelf 10 in the cultivation room 3 to the collection tank 41. And a nutrient solution return path 33 for returning the collected nutrient solution from the recovery tank 41 to the nutrient solution tank 40. The nutrient solution supply path 31, the nutrient solution recovery path 32, and the nutrient solution return path 33 constitute a circulation path in the nutrient solution circulation system 30.

  In the nutrient solution return path 33, a filter 44, a heat absorption side of the heat exchanger 45, a heat sterilizer 46, a heat dissipation side of the heat exchanger 45, and a radiator 47 are arranged along the nutrient solution flow. The nutrient solution tank 40, the recovery tank 41, the filter 44, the heat sterilizer 46, and the heat exchanger 45 are installed in the tank chamber 4.

  The nutrient solution tank 40 stores the nutrient solution supplied to the plant 15, and the stored nutrient solution is supplied to each cultivation shelf 10 through the nutrient solution supply path 31 by the first pump (P 1) 37. Is done. The nutrient solution tank 40 is supplied with raw water, and is also fed with a nutrient solution from the concentrate solution tank 43 via the nutrient solution management device 42. The nutrient solution is diluted to an optimum concentration in the nutrient solution tank 40 and is fed to the nutrient solution. Is configured to manufacture. The nutrient solution recovered and heat-sterilized is added to the new nutrient solution made by diluting the stock solution.

  The nutrient solution management machine 42 manages the amount of the stock solution supplied to the nutrient solution tank 40. The nutrient solution management machine 42 detects the hydrogen ion concentration (pH) and electrical conductivity (EC) of the nutrient solution in the nutrient solution tank 40 and controls the amount of the stock solution supplied to the nutrient solution tank 40. The amount of raw water supplied to the nutrient solution tank 40 is controlled by a control device (not shown).

  The collection tank 41 stores a nutrient solution (also referred to as a collected nutrient solution) collected from each cultivation shelf 10 through the nutrient solution recovery path 32. The collected nutrient solution stored in the collection tank 41 is returned to the nutrient solution tank 40 through the nutrient solution return path 33. The nutrient solution return path 33 includes a second pump (P2) 38 and a third pump (P3) 39.

  The filter 44 removes impurities contained in the collected nutrient solution. The heat exchanger 45 heat-exchanges the nutrient solution sent to the heat sterilizer 46 and the nutrient solution passed through the heat sterilizer 46, thereby preheating the nutrient solution before heating and reducing the rough heat of the nutrient solution after heating. To be removed.

  The heat sterilizer 46 heats the collected nutrient solution to the sterilization temperature to kill pathogenic bacteria and the like contained in the nutrient solution. The sterilization temperature is strictly determined by the pathogenic bacteria to be sterilized, but is set to 75 to 80 ° C., for example. The sterilization time is, for example, about several minutes. In the plant factory 1 of the present embodiment, a heat pump type heat sterilizer with high energy conversion efficiency is used as the heat sterilizer 46.

  The radiator 47 radiates the heat of the nutrient solution from which the rough heat has been removed by the heat exchanger 45. What should be noted here is the place where the radiator 47 is installed. As shown in FIG. 1, the radiator 47 is installed in the cultivation room 3 by extending the nutrient solution return path 33 from the tank room 4 into the cultivation room 3. Thus, the heat of the heat-sterilized nutrient solution is radiated by the radiator 47 to cool the nutrient solution, and the air in the cultivation room 3 can be warmed by the heat. The nutrient solution return path 33 leading to the cultivation room 3 is insulated.

  Moreover, in the plant factory 1 of the present embodiment, as a more preferable configuration, the position where the air flow that is heat exchanged (cooled) by the cooler 21 of the air conditioner 20 directly hits the radiator 47, specifically, the air It arrange | positions in front of the blower outlet 23. FIG. Thereby, the cooled air which blows off from the air conditioner 20 directly hits the heat radiator 47, and heat exchange with the heat radiator 47 and air is performed more effectively. As a result, the nutrient solution can be cooled more effectively, and the cold air blown from the air conditioner 20 can be sent to the cultivation room 3 after being warmed by the heat radiated from the radiator 47. .

Here, the radiator 47 is arranged in front of the air outlet 23, but the radiator 47 may be arranged in the air conditioner 20 at a position where the air flow cooled by the cooler 21 directly hits. In this case, the air warmed by the radiator 47 is blown out from the air outlet 23 of the air conditioner 20.

  Further, a short-circuit path 34 for flowing the nutrient solution to the nutrient solution tank 40 without being sent to the radiator 47 is branched between the heat radiation side of the heat exchanger 45 and the radiator 47 in the nutrient solution return channel 33. Is formed. Valves 51 and 52 are provided on the radiator 47 side of the branch point (before reaching the third pump 39) and the short circuit path 34. Accordingly, by controlling the opening of the valves 51 and 52, part or all of the nutrient solution output from the heat radiation side of the heat exchanger 45 is directly passed to the nutrient solution tank 40 without passing through the radiator 47. Can be sent.

  Further, although not shown in the drawing, temperature sensors for measuring the temperature of the nutrient solution are provided at important points of the nutrient solution tank 40 and the nutrient solution return path 33. Based on the measurement results of these temperature sensors, the opening of the valves 51 and 52 is controlled as described later.

  Next, operation | movement of the plant factory 1 which has the said structure is demonstrated. In the plant factory 1, the lighting device and the air conditioner 20 are controlled so that the light period corresponding to the daytime and the dark period corresponding to the night time are alternately generated in the cultivation room 3. Moreover, in the plant factory 1, the nutrient solution circulation system 30 is controlled and the nutrient solution is supplied to the plant 15 in the cultivation room 3 at a frequency of 3 to 4 times per day.

  In the light period, the lighting device is turned on, and the air conditioner 20 is cooled at the set temperature in the light period. The set temperature in the light period is an appropriate daytime temperature suitable for the plant 15, and is strictly determined by the plant 15 to be cultivated. In a general plant factory, it is set to 20-25 degreeC, for example.

  In the light period, heat is emitted from the illuminating lighting device, so that the air conditioner 20 operates appropriately to suppress the temperature increase in the cultivation room 3 and keep the temperature set in the light period. Therefore, in the light period, even if the amount of moisture in the air increases due to the transpiration of the plant 15, dehumidification is performed without any problem by the cooling operation of the air conditioner 20, and the humidity is kept in a range suitable for the growth of the plant 15. Be drunk.

  On the other hand, in the dark period, the lighting device is turned off, and the set temperature of the air conditioner 20 is set to the forced operation temperature to perform the cooling operation. In this dark period, the collected nutrient solution stored in the collection tank 41 is sterilized.

  The forced operation temperature is a temperature lower than the optimal nighttime temperature suitable for the plant 15 for forcing the air conditioner 20 to perform continuous operation. The nighttime suitable temperature suitable for the plant 15 is strictly determined by the plant 15 to be cultivated, but when the optimum nighttime temperature suitable for the plant 15 is 10 to 15 ° C., the forced operation temperature is lower than that, for example, 4 ~ 7 ° C.

  When the set temperature of the air conditioner 20 is the forced operation temperature of 4 to 7 ° C., the room temperature of the cultivation room 3 becomes too low and may affect the growth of the plant 15. Therefore, the air at 4 to 7 ° C. blown out from the air conditioner 20 is heated by exchanging heat with the radiator 47. As a result, the temperature in the cultivation room 3 can be set to, for example, 10 to 15 ° C. suitable for the plant 15.

  Here, the ideal temperature of the nutrient solution in each part of the nutrient solution return path 33 when the plant factory 1 is operated with the preset temperature of the light period being 22 ° C., the forced operation temperature being 5 ° C., and the sterilization temperature being 80 ° C. Illustrate.

The nutrient solution collected in the collection tank 41 is sent to the nutrient solution return path 33 by the second pump (P2) 38. The fed nutrient solution passes through the filter 44, passes through the heat absorption side of the heat exchanger 45, enters the heat sterilizer 46, is heated, and is output from the heat dissipation side of the heat exchanger 45. The nutrient solution that is at room temperature (20 ° C.) at the inlet portion (A) on the heat absorption side of the heat exchanger 45 is heat exchanged with the nutrient solution heated to 80 ° C. when passing through the heat absorption side of the heat exchanger 45. By doing so, it can preheat to about 50 degreeC in the exit part (B) of the heat absorption side of the heat exchanger 45. FIG. On the other hand, the nutrient solution that has been sterilized by heating and has passed through the heat dissipation side of the heat exchanger 45 is about 80 ° C. at the inlet portion (C) on the heat dissipation side of the heat exchanger 45. By performing heat exchange, the heat exchanger 45 can be cooled to about 40 ° C. at the heat radiation side outlet portion (D).

  Next, the nutrient solution is cooled by passing through the radiator 47 by the third pump (P3) 39. When the room temperature of the cultivation room 3 in the dark period is about 15 ° C. lower than the room temperature (20 ° C.), the nutrient solution is cooled to, for example, about 25 to 30 ° C. at the folded portion (E) of the radiator 47. At this time, the air discharged from the air conditioner 20 is heated by the heat released from the nutrient solution, and a mechanism similar to reheat dehumidification is configured. Thereafter, the nutrient solution is further cooled in the course of reaching the nutrient solution tank 40 and is lowered to room temperature (20 ° C.) at the inlet portion (F) of the nutrient solution tank 40.

  In addition, the temperature of the nutrient solution in each part (A) to (F) of the nutrient solution return path 33 is a second pump that affects the path length of the nutrient solution return path 33 up to each part and the flow rate of the nutrient solution flowing ( It changes also with the power of P2) 38 and the 3rd pump (P3) 39.

  FIG. 2 is a graph showing changes in temperature and humidity in the cultivation room when the humidity is adjusted using the air conditioner 20 and the heat radiation from the radiator 47. On the other hand, FIG. 3 is a graph showing changes in temperature and humidity in the cultivation room when the humidity is adjusted only by the air conditioner 20.

  2 and 3, from 18:00 to 6:00 is a dark period when the lighting device is turned off, and from 6:00 to 18:00 is a light period when the lighting device is turned on. 2 and 3, since the lighting device acts as a heat source in the light period, the air conditioner 20 operates in a timely manner, and the room temperature of the cultivation room 3 is maintained at the set temperature in the light period of the air conditioner, and the humidity. Is maintained at about 80%. It is generally said that the humidity suitable for plant growth is less than 90%. When the humidity is 90% or higher, condensation on the plant is likely to occur, which hinders growth.

  On the other hand, in the dark period when the lighting device is turned off and the heat source disappears, the room temperature of the cultivation room 3 is in the dark period immediately after the set temperature of the air conditioner 20 is switched as shown in FIGS. Since the air conditioner 20 operates to reach the set temperature, the humidity also decreases. However, when the temperature falls to the set temperature, the operation is stopped thereafter. As described above, since the cultivation room 3 is configured as a closed space in which heat insulating properties and light shielding properties are ensured, the temperature does not increase unless some heat source acts.

  As a result, as shown in FIG. 3, when the humidity is adjusted only with the air conditioner 20, the room temperature of the cultivation room 3 continues to rise after reaching the set temperature in the dark period (appropriate temperature at night) and 100%. turn into. On the other hand, as shown in FIG. 2, when using heat radiation from the radiator 47, the inside of the cultivation room 3 is warmed by the heat from the radiator 47. The temperature does not drop to (operating temperature). Therefore, the air conditioner 20 operates appropriately, the room temperature of the cultivation room 3 is maintained at a suitable temperature at night, and the humidity is also maintained at about 80%.

  By the way, depending on conditions, such as ambient temperature, the temperature of the nutrient solution which returns through the radiator 47 may be cooled below normal temperature (20 degreeC). In that case, the temperature of the nutrient solution in the nutrient solution tank 40 becomes lower than normal temperature. Since the temperature of the nutrient solution supplied to the plant 15 is preferably normal temperature, it is not so preferable that the temperature of the nutrient solution in the nutrient tank 40 is lower than normal temperature.

Therefore, in such a case, by controlling the opening and closing of the valve 51 and the valve 52, part or all of the nutrient solution sent to the radiator 47 is temporarily stored in the nutrient solution tank 40 via the short-circuit path 34. To introduce. Thereafter, when the temperature of the nutrient solution in the nutrient solution tank 40 returns to room temperature, the valves 51 and 52 are returned to their original positions. Such opening / closing control of the valves 51 and 52 may be performed manually or automatically by a control device based on the temperature of the nutrient solution in the nutrient solution tank 40.

[Embodiment 2]
Hereinafter, another embodiment of the present invention will be described with reference to FIG. For convenience of explanation, members having the same functions as those in the drawings described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

  FIG. 4 is a schematic diagram showing the configuration of the plant factory according to the present embodiment. As shown in FIG. 4, in the plant factory 1a of the present embodiment, the detour 35 for flowing the nutrient solution to the radiator 47 without passing through the heat exchanger 45 through the nutrient solution return path 33a of the nutrient solution circulation system 30a. Is formed by branching. Valves 53, 55, and 54 are provided on the heat exchanger 45 side of the branch point upstream of the bypass route 35, the heat exchanger 45 side of the branch point downstream of the bypass route 35, and the bypass route 35. . By closing the valves 53 and 55 and opening the valve 54, the nutrient solution passed through the heat sterilizer 46 can be sent directly to the radiator 47 without passing through the heat exchanger 45.

  For example, depending on conditions such as ambient temperature, when the temperature of the nutrient solution coming out from the heat radiating side of the heat exchanger 45 is low and the room temperature of the cultivation room 3 cannot be warmed to an appropriate temperature at night, the valves 53 to 55 Opening and closing is controlled, and the heated nutrient solution is sent directly to the cultivation room 3. Then, when the room temperature of the cultivation room 3 reaches the nighttime appropriate temperature, the valves 53 to 55 are returned to the original state. Such opening / closing control of the valves 53 to 55 may be performed manually, or may be automatically performed by the control device based on the room temperature of the cultivation room 3.

  As another measure for preventing the temperature of the nutrient solution coming out from the heat radiating side of the heat exchanger 45 from becoming too low, the flow path in the heat exchanger 45 can be switched, and the heat radiating from the heat exchanger 45 can be performed. When the temperature of the nutrient solution coming out from the side is low, the flow path may be switched to a short one.

  In addition, when the bypass 35 is provided, the heated nutrient solution is directly flowed to the nutrient solution tank 40 using the short-circuit path 34, so that the sterilization process in the nutrient solution tank 40 can be performed.

[Embodiment 3]
Hereinafter, another embodiment of the present invention will be described with reference to FIG. For convenience of explanation, members having the same functions as those in the drawings described in the embodiment are given the same reference numerals, and descriptions thereof are omitted.

  FIG. 5 is a schematic diagram showing the configuration of the plant factory according to the present embodiment. As shown in FIG. 5, in the plant factory 1b of the present embodiment, the nutrient solution is fed to the nutrient solution return path 33a of the nutrient solution circulation system 30a shown in FIG. A path 36 that flows to the liquid supply path 31 is formed by branching. Valves 56, 57, and 58 are provided on the radiator 47 side of the branch point upstream of the path 36, the nutrient solution tank 40 side of the branch point downstream of the path 36, and the path 36.

  As a result, the nutrient solution heated by the heat sterilizer 46 is guided to the third pump (P3) 39 through the bypass 35, and the valves 56 and 57 are closed and the valve 58 is opened to be heated. By flowing the nutrient solution directly into the nutrient solution supply path 31 using the path 36, each cultivation shelf 10 can be sterilized.

[Summary]
The plant factory which concerns on 1 aspect of this invention has the cultivation container 11 in the cultivation room 3 for cultivating a plant, the illuminating device, and the air conditioner 20 are arrange | positioned, and the nutrient solution is supplied to the plant 15 accommodated in the said cultivation container 11 A nutrient solution circulation system 30 is provided for collecting the surplus nutrient solution and supplying it again and supplying it to the circulation path (nutrient return route 33) for returning the nutrient solution collected in the nutrient solution circulation system 30 to the supply side. In the plant factory 1 in which the heat sterilization apparatus 46 for heat sterilizing the collected nutrient solution is disposed, a circulation path downstream of the heat sterilization apparatus 46 is extended to the cultivation room 3 and the cultivation room 3 It is characterized in that a radiator 47 is provided in a portion extending up to.

  According to the above configuration, the nutrient solution heated by the heat sterilizer 46 is cooled while flowing through the circulation path extended to the cultivation room 3 and passes through the radiator 47 arranged in the path. It is cooled effectively. And since the heat radiator 47 is arrange | positioned by the air conditioner 20 in the cultivation room 3 managed by the temperature suitable for a plant low enough compared with the heated nutrient solution, heat radiation is performed more effectively. Is called. Therefore, the power consumption of the pump that feeds the nutrient solution may increase slightly as the path length becomes longer, but the nutrient solution can be cooled to the normal temperature level without providing a cooling mechanism that absorbs heat electrically. As a result, the power consumption required for cooling the nutrient solution can be reduced.

  In addition, by providing the radiator 47 in the cultivation room 3, the cultivation room 3 can be warmed using heat generated from the radiator 47. Therefore, for example, by using the heat generated from the radiator 47 as a heat source for warming the air after dehumidification, the reheating dehumidifying operation with high power consumption is performed while the air conditioner 20 performs the cooling operation. It is possible to obtain the same effect as the case of making them. That is, it is possible to prevent the cultivation room from becoming high humidity without causing the air conditioner 20 to perform the reheat dehumidification operation.

  Furthermore, the plant factory 1 which concerns on 1 aspect of this invention WHEREIN: The said heat radiator 47 is the position where the airflow cooled by the cooling part (cooler 21) with which the said air conditioner (air conditioner 20) was directly applied. It is preferable to have a configuration arranged in the above.

  By directly applying heat to the radiator 47 with the cold air cooled by the cooler 21, heat radiation by the radiator 47 is more effectively performed, and the cold air before being warmed is contained in the cultivation room 3. It is possible to reliably avoid problems such as impeding the growth of some plants.

  Furthermore, the plant factory 1 which concerns on 1 aspect of this invention makes the said dark period in the growth process which makes the light period which lights the said illuminating device, and the dark period which turns off the said illuminating device alternately, and grows the said plant. The heat sterilization of the nutrient solution by the heat sterilizer 46 is preferable.

  Since the lighting device generates heat, it becomes a heat source in the cultivation room 3. During the light period when the lighting device is turned on, the room temperature rises due to the heat generated by the lighting device, so the air conditioner 20 operates in a timely manner to cool the air to the set temperature. Thereby, dehumidification is performed without a problem. However, in the dark period when the lighting device is turned off, heat is not emitted from the lighting device, so the room temperature does not rise. Therefore, the air conditioner 20 stops operation when the cultivation room is cooled to the set temperature. As a result, the dehumidification of the cultivation room is not performed and the humidity increases.

  According to the above configuration, since the collected nutrient solution is sterilized by heating and the cultivation room 3 is warmed by the radiator 47 in the dark period when the humidity increases, the set temperature of the air conditioner 20 is set to the radiator. It is possible to set the temperature to be low considering the warming by heat from 47, and the same effect as when the reheat dehumidifying operation is performed while the air conditioning device 20 is performing the cooling operation can be obtained.

  Furthermore, in the plant factory 1 according to one aspect of the present invention, the heat sterilizer 46 is preferably a heat pump system.

  In general, in a heat pump cycle, the greater the temperature difference between the high temperature side and the low temperature side, the greater the amount of work of the compressor and the higher the power consumption, and the lower the energy efficiency of the heat sterilizer equipped with the heat pump cycle. In the techniques described in Patent Documents 1 and 2 described above, in order to cool the nutrient solution heated on the high temperature side of the heat pump cycle, the low temperature side of the heat pump cycle is set to a temperature lower than normal temperature, The temperature difference on the low temperature side is large.

  On the other hand, according to the above configuration, since the cold air of the air conditioner is used for cooling the nutrient solution after heating, it is not necessary to set the low temperature side of the heat pump cycle of the heat sterilizer to a temperature lower than the normal temperature. And the temperature difference on the low temperature side can be reduced. For example, in the techniques described in Patent Documents 1 and 2, the high temperature side is 90 ° C. and the low temperature side is 10 ° C. (temperature difference is 80 ° C.). Temperature difference 70 ° C.). By reducing the temperature difference between the high temperature side and the low temperature side, the cycle load is reduced, and the energy efficiency of the heat sterilizer 46 can be increased.

  Furthermore, in the plant factories 1a and 1b according to one aspect of the present invention, the nutrient solution circulation system 30 supplies the nutrient solution stored in the nutrient solution tank 40 to the plant 15, and collects the excess nutrient solution. After heat sterilization by the heat sterilizer 46, the nutrient solution is returned to the nutrient tank 40, and the collected nutrient solution is returned to the circulation path (the nutrient solution return path 33a, 33b). A heat exchanger 45 for exchanging heat between the nutrient solution sent to the heat sterilizer 46 and the nutrient solution passed through the heat sterilizer 46 is disposed, and the nutrient solution passed through the heat sterilizer 46 is exchanged with the heat. It is also possible to employ a configuration in which a detour path 35 is provided to the radiator 47 without being sent to the radiator 45.

  According to the said structure, the nutrient solution which passed through the heat sterilizer 46 can be sent directly to the heat radiator 47, without letting the heat exchanger 45 pass using the detour path 35. FIG. Therefore, when the temperature of the nutrient solution passing through the heat exchanger 45 is low to raise the room temperature of the cultivation room 3 and the effect of reheat dehumidification cannot be expected so much, the heat sterilizer 46 is used using the detour 35. By sending the passed nutrient solution directly to the radiator 47, the room temperature of the cultivation room 3 is raised and effective dehumidification becomes possible.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  INDUSTRIAL APPLICABILITY The present invention can be used for a fully-controlled plant factory that produces plants such as vegetables and fruits in a completely controlled environment in a closed space separated from the outside.

1, 1a, 1b Plant factory 2 Building 3 Cultivation room 4 Tank room 10 Cultivation shelf 11 Cultivation container 13 Cultivation floor 15 Plant 20 Air conditioner (air conditioner)
21 Cooler (cooling part)
23 Air outlet 30, 30a, 30b Nutrient solution circulation system 31 Nutrient solution supply route (circulation route)
32 Nutrient solution recovery route (circulation route)
33, 33a, 33b Nutrient solution return path (circulation path)
35 Detour 40 Nutrient tank 41 Recovery tank 42 Nutrient management machine 43 Stock solution tank 45 Heat exchanger 46 Heat sterilizer 47 Radiator

Claims (5)

A cultivation container, a lighting device, and an air conditioner are arranged in a cultivation room for cultivating a plant, supplying nutrient solution to the plant accommodated in the cultivation container, recovering surplus nutrient solution, and supplying it again In a plant factory where a nutrient solution circulation system is provided, and a heat sterilizer for heating and sterilizing the collected nutrient solution is disposed in a circulation path for returning the nutrient solution collected in the nutrient solution circulation system to the supply side,
A plant factory characterized in that a circulation path downstream of the heat sterilizer extends to the cultivation room, and a radiator is provided in a portion extending to the cultivation room.   The plant factory according to claim 1, wherein the radiator is arranged at a position where an air flow cooled by a cooling unit provided in the air conditioner directly hits.   In the growing process of growing the plant by alternately creating a light period for turning on the lighting device and a dark period for turning off the lighting device, heat sterilization of the nutrient solution by the heat sterilizer is performed in the dark period. The plant factory according to claim 1 or 2.   The plant factory according to any one of claims 1 to 3, wherein the heat sterilizer is a heat pump system.   The nutrient solution circulation system supplies the nutrient solution stored in the nutrient solution tank to the plant, collects the surplus nutrient solution, sterilizes by heat with the heat sterilizer, and then returns to the nutrient solution tank. And a heat exchanger for exchanging heat between the nutrient solution sent to the heat sterilizer and the nutrient solution passed through the heat sterilizer is disposed in a circulation path for returning the collected nutrient solution to the nutrient solution tank. In addition, a detour for sending the nutrient solution that has passed through the heat sterilizer to the heat radiator without sending it to the heat exchanger is provided. Plant factory.

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