Heating system utilizing solar heat

Abstract

To provide a hot water heating system which utilizes solar heat and can efficiently heat a greenhouse while preventing pipes from freezing, and can perform detailed temperature control without requiring manpower on-site.SOLUTION: A heating system utilizing solar heat of the present invention comprises: a heating medium circulation unit which absorbs solar heat and circulates the heated heating medium; a hot water circulation unit which stores hot water having become hot by receiving heat from the circulating heating medium in a hot water storage tank and circulates hot water in water circulation piping; a hot air supply unit which generates hot air by using the heat of the hot water circulating in the hot water circulation piping; and a control unit which controls each unit according to the sunlight conditions and / or the conditions inside an agricultural greenhouse. The control unit is composed of: detection means which detects physical quantities inside and outside the agricultural greenhouse; and a management terminal which monitors the physical quantities detected by the detection means and sends instructions to each unit.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a heating system that utilizes solar heat, and in particular to a technology for reducing the amount of fossil fuel used for heating an agricultural greenhouse. [Background technology]

[0002] For crops such as strawberries, cucumbers, eggplants, and tomatoes that are grown in greenhouses from winter to summer, temperature control inside the greenhouse is important for their proper cultivation. Especially in winter, various measures are taken to prevent the temperature inside the greenhouse from dropping too low.

[0003] For example, strawberry farmers in Tochigi Prefecture sprinkle water inside the greenhouse at night to heat it up, and also prevent the spread of heat by making the greenhouse itself a double-layered structure. They also use oil boilers for heating depending on the temperature inside the greenhouse, allowing for detailed temperature control.

[0004] However, heating with oil boilers poses the problem of carbon dioxide emissions due to the use of fossil fuels, and the fuel costs are also high, making it difficult to reduce production costs.

[0005] Therefore, efforts are being made to reduce the use of fossil fuels by using solar heating (Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2008-220217 A Summary of the Invention [Problem to be solved by the invention]

[0007] According to the technology disclosed in Patent Document 1, hot water heated by a solar water heater during the day is stored in a hot water storage tank, and the stored hot water is supplied to a heat radiator to heat the inside of the greenhouse. With such a system, hot water generated using solar heat can be used for heating, which reduces the use of fossil fuels for heating.

[0008] However, the invention disclosed in Patent Document 1 is a system that circulates hot water generated using solar heat as a medium, and there is a risk that the pipes that circulate the water will freeze in winter. In addition, the temperature inside the greenhouse must be controlled using a control panel installed on-site, so during winter nights and other times, manpower is required to operate the control panel to control the temperature, which leads to increased production costs.

[0009] The present invention has been made in consideration of such problems, and aims to provide a hot water heating system that uses solar heat to efficiently heat a greenhouse while preventing pipes from freezing, and that can perform detailed temperature control without requiring manpower on-site. [Means for solving the problem]

[0010] The present invention provides the following solutions.

[0011] The heating system utilizing solar heat according to the first feature includes a heat medium circulation unit that absorbs solar heat and heats the heat medium, and circulates the heated heat medium in a heat medium circulation piping; a hot water circulation unit that stores hot water that has been heated by the heat medium circulating in the heat medium circulation piping in a hot water storage tank and circulates the hot water in the water circulation piping; a hot air supply unit that generates hot air by utilizing the heat contained in the hot water circulating in the hot water circulation piping; and a control unit that controls the heat medium circulation unit, the hot water circulation unit, and the hot air supply unit depending on the sunlight conditions and / or the conditions inside the agricultural greenhouse.

[0012] The control unit is composed of a detection means for detecting physical quantities inside and outside the agricultural greenhouse, and a management terminal for monitoring the physical quantities detected by the detection means and transmitting instructions to the heat medium circulation unit, the hot water circulation unit, and the hot air supply unit.

[0013] According to the first aspect of the invention, the heat medium heated by absorbing solar heat is circulated in the heat medium circulation piping, and hot water heated by heat from the heat medium circulating in the heat medium circulation piping is stored in the hot water storage tank and circulated in the water circulation piping. Therefore, antifreeze, which is less likely to freeze than water, can be used as the heat medium, and a heating system that makes effective use of solar heat and can suppress carbon dioxide emissions while preventing the pipes from freezing in winter, etc. can be obtained.

[0014] In addition, the control unit monitors the physical quantities detected by the detection means and is equipped with a management terminal that sends instructions to the heat medium circulation unit, the hot water circulation unit, and the hot air supply unit, so that each unit can be controlled even if the user is not present. Effect of the Invention

[0015] According to the present invention, a hot water heating system that utilizes solar heat can efficiently heat a greenhouse while preventing pipes from freezing, and a heating system that utilizes solar heat can be provided that can perform detailed temperature control without requiring manpower on-site. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic diagram showing the overall configuration of a heating system that utilizes solar heat according to this embodiment. [Diagram 2] FIG. 2 is a flowchart of a heat storage operation using the heating system utilizing solar heat according to this embodiment. [Diagram 3] FIG. 3 is a flowchart of a heating operation using the heating system utilizing solar heat according to this embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that this is merely an example, and the technical scope of the present invention is not limited to this example.

[0018] [Overall configuration of solar heating system 1] The overall configuration of a heating system 1 that utilizes solar heat according to this embodiment will be described with reference to FIG.

[0019] As shown in FIG. 1, the heating system 1 utilizing solar heat according to this embodiment includes a heat medium circulation unit 10 that absorbs solar heat and circulates the heated heat medium, a hot water circulation unit 20 that stores hot water that has been heated by receiving heat from the heat medium circulating in the heat medium circulation unit 10 and circulates it through piping, a hot air supply unit 30 that generates hot air in an agricultural greenhouse by utilizing the heat contained in the hot water circulating in the hot water circulation unit 20, and a control unit 40 that controls the heat medium circulation unit 10, the hot water circulation unit 20, and the hot air supply unit 30 according to the sunlight conditions and / or the conditions inside the agricultural greenhouse.

[0020] The heat medium circulation unit 10 is a unit that circulates a heat medium heated by absorbing solar heat, and is composed of a solar heat collector 11 that is installed on the roof of an agricultural greenhouse or the like and absorbs solar heat to heat a heat medium such as antifreeze, a heat medium circulation pipe 12 through which the heat medium such as antifreeze flows, and a heat medium circulation pump 13 that circulates the heat medium in the heat medium circulation pipe 12. The heat medium circulation pipe 12 is connected to a heat exchanger 22 installed in a hot water storage tank 21 described later. Although not shown in the figure, a flow path through which the heat medium flows is formed inside the solar heat collector 11. In the heat medium circulation unit 10, the heat medium that has been heated to a high temperature of about 80°C by receiving heat in the solar heat collector 11 circulates in the heat medium circulation pipe 12 by the operation of the heat medium circulation pump 13.

[0021] The hot water circulation unit 20 is a unit that circulates hot water that has been heated by the heat medium circulating in the heat medium circulation unit 10, and is composed of a hot water storage tank 21 that generates and stores hot water, a heat exchanger 22 that is connected to the heat medium circulation piping 12 and transfers the heat of the heat medium to the water stored in the hot water storage tank 21, a water circulation piping 23 that supplies the hot water generated in the hot water storage tank 21 to the hot air generation unit 30 and returns the water whose temperature has been reduced by using the heat to the hot water storage tank 21, an auxiliary heater 24 that is installed in the hot water storage tank 21 and heats the hot water stored in the hot water storage tank 21, an auxiliary boiler 25 that is installed in the middle of the water circulation piping 23 between the hot air generation unit 30 and the hot water storage tank 21 and heats the water whose temperature has been reduced by using the heat in the hot air generation unit 30, and a water circulation pump 26 that forms the circulation of water present in the hot water storage tank 21 and the water circulation piping 23. The heat exchanger 22 is configured to be wound around the lower part of the hot water storage tank 21. In hot water circulation unit 20, heat is transferred from the high-temperature heat medium circulating in heat exchanger 22 to the water stored in hot water storage tank 21, turning the water into hot water of about 60°C, which is circulated in water circulation piping 23 by operation of water circulation pump 26. When the amount of solar radiation is insufficient, a sufficient amount of hot water is stored in hot water storage tank 21 by operating auxiliary heater 24.

[0022] The hot air generating unit 30 generates hot air by utilizing the heat of the hot water supplied from the hot water storage tank 21 through the water circulation pipe 23, and is composed of a radiator 31 connected to the water circulation pipe 23, and a blower 32 for blowing air to the radiator 31 to generate hot air inside the agricultural greenhouse. In the hot air generating unit 30, heat is transferred from the hot water flowing inside the radiator 31 to the air supplied toward the radiator 31 by the operation of the blower 32, and the air becomes hot air and is diffused inside the agricultural greenhouse.

[0023] The control unit 40 controls each of the devices that make up the heat medium circulation unit 10, the hot water circulation unit 20, and the hot air generation unit 30 in accordance with the sunlight conditions and the conditions inside the agricultural greenhouse, and is composed of a detection means 41 that detects various physical quantities inside and outside the agricultural greenhouse, a control panel 42 that outputs control signals to the devices that make up each unit, a server 43 that accumulates data and processes the signals to output control signals to the control panel 42, and a management terminal 44 that monitors the various physical quantities detected by the detection means 41 and sends instructions to the heat medium circulation unit 10, the hot water circulation unit 20, and the hot air generation unit 30 via the server 43.

[0024] The detection means 41 detects various physical quantities inside and outside the agricultural greenhouse, and specifically includes temperature sensors installed at various locations inside the agricultural greenhouse, humidity sensors similarly installed at various locations inside the agricultural greenhouse, a concentration sensor that detects the carbon dioxide concentration inside the agricultural greenhouse, an outside air temperature sensor that detects the air temperature outside the agricultural greenhouse, and a solar radiation sensor that detects the amount of solar radiation. The detection means 41 also includes a temperature sensor that detects the temperature of the hot water stored in the hot water storage tank, and temperature sensors that detect the temperatures of the hot water flowing out of the hot water storage tank and the hot water flowing into the hot water storage tank.

[0025] The control panel 42 is connected by wire or wirelessly to each device constituting the heat medium circulation unit 10, the hot water circulation unit 20, and the hot air generation unit 30, receives various physical quantities detected by the detection means 41, and outputs control signals to each device, and is composed of a microcomputer, manual switches, relays, connection terminals, operation display LEDs, error display LEDs, etc. (not shown). The control panel 42 is also connected to a server 43 so as to be able to communicate with it using a network N such as wireless LAN or wi-fi.

[0026] The server 43 is composed of a storage means 43a that stores various physical quantities detected by the detection means 41, a control means 43b that generates control signals for each device, and a communication means 43c that communicates with the control panel 42 and the management terminal 44 using a network N such as wireless LAN or wi-fi. Although the server 43 and the control panel 42 are shown separately in FIG. 1, the server 43 may be configured integrally with the control panel 42. In other words, the control panel 42 may be configured to include the storage means 43a, the control means 43b, and the communication means 43c that constitute the server 43 inside.

[0027] The management terminal 44 is communicatively connected to the server 43 using a network N such as wireless LAN or wi-fi, and is configured to be able to monitor various physical quantities such as the temperature inside the agricultural greenhouse detected by the detection means 41 via the server 43, and transmits instructions to each device constituting the heat medium circulation unit 10, the hot water circulation unit 20, and the hot air generation unit 30 to the control panel 42 via the server 43. The management terminal 44 is configured by a wireless communication terminal such as a smartphone or tablet terminal, or a notebook PC connectable to the network N.

[0028] Preferably, the management terminal 44 is configured as a smartphone, and the temperature inside the agricultural greenhouse is monitored and adjusted by installing an application dedicated to the heating system 1 that utilizes solar heat in this embodiment on the smartphone.

[0029] [Heat storage operation using solar heating system 1] The heat storage operation using the heating system 1 utilizing solar heat according to this embodiment will be described with reference to FIG.

[0030] FIG. 2 is a flowchart illustrating the heat storage operation using the heating system 1 utilizing solar heat according to this embodiment.

[0031] <Step S100: Detecting the amount of solar radiation> First, the solar radiation sensor constituting the detection means 41 detects the amount of solar radiation at that time (step S100).

[0032] <Step S110: Determining the Amount of Solar Radiation> Next, a determination is made as to whether the amount of solar radiation is sufficient (step S110). If it is determined that the amount of solar radiation is sufficient (Y in step S110), the process proceeds to the next step S120, and if it is determined that the amount of solar radiation is insufficient (N in step S110), the process returns to step S100.

[0033] <Step S120: Circulation of Heat Transfer Medium> If it is determined in step S110 that the amount of solar radiation is sufficient, the heat medium circulation pump 13 is operated to circulate the heat medium within the heat medium circulation unit 10 (step S120). At this time, a sufficient amount of solar heat is received in the solar heat collector 11, and the heat medium, which has become high in temperature to about 80°C due to the heat absorbed by the solar heat collector 11, flows into the heat exchanger 22 in the hot water storage tank 21 via the heat medium circulation piping 12 by the operation of the heat medium circulation pump 13.

[0034] <Step S130: Generating Hot Water> Then, heat is transferred from the heat medium that has flowed into the heat exchanger 22 to the water in the hot water storage tank 21, and hot water is generated in the hot water storage tank 21 (step S130). The heat medium that has transferred heat to the water in the heat exchanger 22 and has its temperature reduced to about 15°C returns to the solar heat collector 11 by the operation of the heat medium circulating pump 13, becomes hot again due to the heat absorbed by the solar heat collector 11, and transfers heat to the water in the heat exchanger 22 in the hot water storage tank 21.

[0035] In this manner, hot water is produced in the hot water storage tank 21, and hot water is accumulated in the hot water storage tank 21 by continuing this operation.

[0036] A temperature sensor (not shown) is installed in the hot water storage tank 21 to detect the temperature of the stored water, and when it is determined that a sufficient amount of hot water of a sufficient temperature has been stored, the operation of the heat medium circulating pump 13 is stopped to stop further circulation of the heat medium. If a sufficient amount of hot water cannot be produced due to insufficient solar radiation, the auxiliary heater 24 may be energized to generate hot water by heating with the heater.

[0037] [Heating operation using solar heating system 1] A heating operation using the heating system 1 utilizing solar heat according to this embodiment will be described with reference to FIG.

[0038] FIG. 3 is a flowchart illustrating the heating operation using the heating system 1 that utilizes solar heat according to this embodiment.

[0039] <Step S200: Detecting temperature inside agricultural greenhouse> First, the temperature inside the agricultural greenhouse is detected using a temperature sensor constituting the detection means 41 (step S200).

[0040] <Step S210: Determination of temperature inside agricultural greenhouse> Next, a determination is made as to whether the temperature inside the agricultural greenhouse is below a predetermined value T1 (step S210). If it is determined that the temperature inside the agricultural greenhouse is below the predetermined value T1 (Y in step S210), the process proceeds to the next step S220, and if it is determined that the temperature is equal to or higher than the predetermined value T1 (N in step S210), the process returns to step S200. Such repetition of steps S200 and S210 is performed at predetermined time intervals.

[0041] <Step S220: Circulation of hot water> In step S210, when it is determined that the temperature in the agricultural greenhouse is below the predetermined value T1, the water circulation pump 26 is operated to circulate the hot water stored in the hot water storage tank 21 in the water circulation unit 20 (step S220). At this time, a sufficient amount of hot water is stored in the hot water storage tank 21, and the hot water stored in the hot water storage tank 21 flows into the radiator 31 of the hot air generating unit 30 through the water circulation piping 23 by the operation of the water circulation pump 26. In addition, when the water circulation pump 26 is operated, a notification such as "The temperature in the greenhouse has fallen below the specified value. Do you want to start the operation of the water circulation pump?" is sent to the management terminal 44 via an application installed in the management terminal 44, and the person having the management terminal 44 may instruct the start of the operation of the water circulation pump 26 by pressing a button such as "Yes" or "No" displayed at the same time.

[0042] <Step S230: Generating hot air> Furthermore, if it is determined in step S210 that the temperature inside the agricultural greenhouse is below a predetermined value T1, the blower 32 is operated to send air to the radiator 31, thereby removing heat from the radiator 31 that received heat from the hot water in step S220 and generating hot air. In this way, when the temperature inside the agricultural greenhouse drops, such as during winter nights, hot air can be generated using hot water stored during the day using solar heat.

[0043] The water whose temperature has dropped to about 20°C by removing heat in radiator 31 is returned to hot water storage tank 21, but since the outside air temperature is low, particularly in midwinter, it is necessary to operate water circulation pump 26 and blower 32 continuously to generate hot air, and in this case, the amount of heat stored in hot water storage tank 21 may gradually decrease. In such a case, the temperature of the water flowing into hot water storage tank 21 may be detected, and when the temperature of the water flowing into hot water storage tank 21 falls below a predetermined value, auxiliary boiler 25 may be operated to raise the temperature of the water returning to hot water storage tank 21.

[0044] At this time, whether or not water can be heated by the auxiliary boiler 25 can be determined via an application installed on the management terminal 44, by receiving a notification such as "The temperature of the water flowing into the hot water tank is below a specified value. Do you want to operate the auxiliary boiler?" at the management terminal 44, and the person having the management terminal 44 can instruct the auxiliary boiler 25 to start operating by pressing a button such as "Yes" or "No" that is displayed at the same time.

[0045] In this embodiment, only the use of the hot water stored in the hot water storage tank 21 as a heat source for heating an agricultural greenhouse has been described, but the hot water stored in the hot water storage tank 21 may also be used as hot water required in a hot water swimming pool, a golf course, etc.

[0046] Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. Furthermore, the effects described in the embodiments of the present invention are merely a list of the most preferable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the embodiments of the present invention.

[0047] Furthermore, the above-described embodiment has been described in detail in order to clearly explain the present invention, and the present invention is not necessarily limited to having all of the configurations described. [Industrial Applicability]

[0048] The solar heating system of the present invention can be applied not only to vinyl greenhouses, but also to various agricultural greenhouses constructed of other materials. [Explanation of symbols]

[0049] 1. Solar heating system 10 Heat medium circulation unit 11 Solar thermal collector 12 Heat medium circulation piping 13 Heat transfer medium circulation pump 20 Hot water circulation unit 21 Hot water tank 22 Heat exchanger 23 Water circulation piping 24 Auxiliary heater 25 Auxiliary boiler 26 Water Circulation Pump 30 Hot air generating unit 31 Heat sink 32 Blower 40 Control Unit 41 Detection methods 42 Control Panel 43 Server 44 Management terminal

Claims

[Claim 1] a heat medium circulation unit that circulates a heat medium heated by absorbing solar heat in a heat medium circulation pipe; a hot water circulation unit that stores hot water heated by heat from the heat medium circulating through the heat medium circulation piping in a hot water storage tank and circulates the hot water in the water circulation piping; A hot air supply unit that generates hot air by utilizing heat of the hot water circulating in the hot water circulation pipe; A control unit controls the heat medium circulation unit, the hot water circulation unit, and the hot air supply unit according to the sunshine conditions and / or the conditions inside the agricultural greenhouse, The control unit is composed of a detection means for detecting physical quantities inside and outside the agricultural greenhouse, and a management terminal for monitoring the physical quantities detected by the detection means and transmitting instructions to the heat medium circulation unit, the hot water circulation unit, and the hot air supply unit. A solar heating system.

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