JP5543239B2 - Heat supply system for cultivation facilities - Google Patents

Description

  The present invention relates to a heat supply system for a cultivation facility.

  2. Description of the Related Art Conventionally, as a heat supply system for a cultivation facility, a system that heats water with a boiler to make hot water and circulates it is known as described in Patent Document 1.

JP 2006-204161 A

  However, when making hot water with a boiler like patent document 1, it is a method which is not suitable in the future from the viewpoint of soaring petroleum fuel cost and decarbonization.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a heat supply system for a cultivation facility that performs decarbonization and efficiently supplies heat.

In order to achieve the above object, the present invention provides a heat supply system for a cultivation facility that cultivates an object to be cultivated in soil , provided with a heat pump, and the heat pump includes a heat exchange pipe that exchanges heat with underground heat. And a heat supply pipe for supplying heat generated by the heat pump to the cultivation facility, and the heat supply pipe is disposed horizontally below the root area of the cultivation target, and the heat exchange pipe is It is arranged horizontally below the heat supply pipe and circulates an antifreeze liquid in the heat exchange pipe and the heat supply pipe to exchange heat with the periphery of the heat exchange pipe and the heat supply pipe. And the temperature around the heat exchange pipe is compensated by heat supplied from the heat supply pipe .

  ADVANTAGE OF THE INVENTION According to this invention, the heat supply system of the cultivation facility which manages decarbonization and performs efficient heat supply can be provided.

It is a figure which shows the general view of the cultivation facility (greenhouse) of this invention, and the heat supply system under the soil surface. It is a conceptual diagram of the heat radiating pipe piping and the underground heat exchange piping installed horizontally under the cage and the cage of the present invention. It is the figure which expressed the concept of the heat transfer by primary heat transfer about the heat source ground temperature compensation type underground heat pump system by the horizontal two-layer installation system in the soil of the heat radiating pipe and heat exchange pipe containing the cultivation facility of the present invention.

  Hereinafter, the heat supply system of the cultivation facility which concerns on embodiment of this invention is demonstrated in detail using drawing.

  Conventionally, the heat supply method for facility cultivation, except for the air convection method using an air conditioner, in most cases, supplies hot water to a heat radiating pipe installed low on the ground of the cultivation facility, and radiates the heat by convection movement of air.・ It is a method of supplying heat to the roots and leaves / stems of flower buds, and the heat source is petroleum fuel boiler or hot spring hot water In this method, another facility such as an air conditioner is required to supply cold heat to the facility. When making hot water with a boiler, this method is not suitable in the future in terms of rising fuel costs and decarbonization.

  In addition, the energy efficiency of heat supply by air convection movement is lower than that of conduction / transmission movement method, because the efficiency of heat supply to the roots under the ground in paddy bed cultivation is poor. There is a need for improved heat supply.

  Although an attempt to supply heat to the ground piping by using a geothermal heat pump using a hole well as a heat exchange well can be considered, as long as the heat supply method is based on convection movement of air, the heat source cost is considerable including the hole drilling cost. It takes.

  In general, the conventional method is a groundbreaking energy-saving system that supplies heat to the cultivated vegetables and flowers from below the root area by heat conduction and heat transfer, and at the same time compensates the temperature of the underground heat exchanger installation part as in the present application. Not like that.

  The present invention is a heat supply system necessary for the facility cultivation of vegetables and flowers, where a heat dissipating pipe is horizontally installed in the lower vicinity of the root area in the soil, and an underground heat exchange pipe is horizontally installed in the lower vicinity. By configuring a system coupled to a heat pump, the heat or cold obtained from the underground heat exchange pipe is conducted upward from the heat radiating pipe to supply heat to the root area, and then the heat is transferred to the ground Energy-saving facility cultivation heat supply that has a feedback function that can compensate the underground temperature of the underground heat exchange piping area by heat conducted downward from the heat radiating pipe as well as a wasteful heat supply method that can supply heat to the stem It is intended for production.

  That is, in view of the above circumstances, the present invention focuses on heat supply (heat or cold) at an appropriate temperature to the root area in the soil, which is the most important for growth, in the bed cultivation in the cultivation facility, and heat convection is mainly used. Instead of the conventional method of heat transfer, a heat transfer method mainly adopting heat conduction and heat transfer from the heat radiation pipe installed horizontally in the ground is adopted to resemble floor heating. As a result, the utilization efficiency of heat supply heat energy to the leaves and stems is increased by upward heat transfer.

  By constructing a system in which the heat radiation pipe installed horizontally and the underground heat exchanger horizontally installed below it are connected to the heat pump, the heat energy of the downward heat conduction from the heat radiation pipe is Since the ground temperature changed by heat exchange can be compensated, the heat source efficiency can be compensated and the heat pump coefficient of performance can be used to reduce the amount of oil used in the heat source and save electricity. Since heat exchanging piping is possible by civil engineering construction, the profitability of institutional cultivation can be further improved as a whole.

  In other words, the present invention dissipates heat to a depth of about 50 cm below the surface of the deeper koji surface lower than the root area of leafy vegetables, fruit vegetables, flower buds, etc., in the soil under the heddle and heddle of about 50 cm width in the cultivation facility. The pipes are horizontally laid, and the underground heat exchange pipes are horizontally laid under a pit about 50 cm deeper than that. Construct a thermal heat pump system.

  Diurnal changes in soil temperature are generally about 1 ° C at a depth of 50 cm and almost zero at a depth of 1 m. Therefore, it can be evaluated that a heat radiating pipe and a ground heat exchange pipe are installed in a natural and stable ground temperature field on a daily basis.

  As a standard model of temperature control system for facility cultivation regardless of the season, standard temperature of soil root area, facility inside and outside air is set, heat dissipation coefficient from heat radiation pipe to root area, soil root area to facility inside It is necessary to set the heat transfer coefficient to the outside and the heat transfer coefficient from the inside of the facility to the outside air, and create a steady heat transfer environment from the heat radiating pipe to the outside air based on them. As a means for this, the temperature of the soil is adjusted with the temperature of the radiator pipe hot water, and the temperature inside the facility is adjusted with a heat-shielding blind or an air-conditioning air conditioner installed as an auxiliary function, thereby creating a steady heat transfer environment from the radiator pipe to the outside air. Can be made.

  At a depth of 50cm and 1m, the annual change in ground temperature is about 25 ° C and 20 ° C in snowy countries (for example, Akita), respectively, but the soil root zone temperature can be maintained by adjusting the temperature of the heat-radiating pipe. It is possible to realize the ground temperature of the underground heat source field to almost constant ground temperature throughout the year by heat.

(Effect 1)
According to the system of the present invention, this system enables winter farming by facility cultivation in a snowy country, regardless of the season.

(Effect 2)
It is a cultivation type system similar to floor heating mainly for heat conduction and heat transfer similar to ascending from the root region to leaves and stems in one system. It is possible to manage the temperature of facility cultivation only by the role mode conversion operation of the two heat exchangers.

(Effect 3)
Although the heat source field for underground heat exchange is as shallow as about 1 m in depth, stable underground heat exchange efficiency can be realized by maintaining a substantially constant ground temperature by downward heat transfer from the heat radiating pipe.

(Effect 4)
The heat energy from the heat radiating pipe can be produced with 1/3 to 1/4 of the heat pump electric energy, it is not necessary to make hot water in the boiler, the carbon dioxide emission is large, and it can rise in the future It is effective as an energy-saving infrastructure centering on renewable energy in facility-grown agriculture that moves away from the use of petroleum-based fuels and shifts to a low-carbon society in an effort to improve economy.

(Example)
As an example of a general cultivation facility of size and specification, the implementation model is a facility whose surface is made of vinyl and has an effective cultivation floor area of 400m ² (20m x 20m rectangle). As the temperature distribution of greenhouse cultivation, the optimum temperature for cultivation of vegetables and flowers is 15 ℃ to 25 ℃, the soil root zone temperature is 20 ℃ in winter and summer, the outside air average temperature is 0 ℃ in winter, 30 ℃ in summer, The temperature inside the facility is set to 10 ° C in winter and 20 ° C in summer, where photosynthesis is possible for normal crops.

  As the horizontal piping form of the radiator pipe, a down trunk pipe from which hot water (or cold water) flows out from the cushion tank to the radiator pipe and an upstream trunk pipe into which the inflow flows are provided. A branch pipe unit pierced in series below is installed for all armpits.

  As the horizontal piping form of the underground heat exchange pipe, a down trunk pipe where antifreeze liquid flows out from the heat exchanger on the ground heat source side of the heat pump to the underground heat exchanger and an upstream trunk pipe into which it flows are provided, and these two trunk pipes A branch pipe unit that is branched from and pierced several rows of armpits in series is installed for all armpits.

  In addition to the fluid circulation circuit with the radiator pipe, the cushion tank has a circuit for circulating hot water and cold water with the heat exchanger on the secondary side of the heat pump, and hot and cold water with the fan coil unit installed in the facility as an auxiliary function. Circulating circuits are connected.

  A movable heat-insulating curtain is installed on the roof and walls of the vinyl facility.

  Use the most commonly used cross-linked polyethylene pipes for heat radiation horizontal pipes under the root zone and underground heat exchange horizontal pipes with relatively good thermal conductivity and impact resistance.

  FIG. 1 shows an overview of a cultivation facility (greenhouse) 10 and its heat supply system below the soil surface.

  The heat supply system of the present invention includes a heat radiation pipe horizontal pipe (heat supply pipe 17) below the root zone in the soil 15 and a ground heat exchange horizontal pipe (heat exchange pipe 16) below the heat pump main body 14, It comprises a cushion tank 13 and a fan coil unit 12 as an auxiliary heat supply function.

  The cultivation facility (greenhouse) 10 may be covered with a heat shielding curtain 11.

  FIG. 2 is a conceptual diagram of the heat radiating pipe 16 and the underground heat exchange pipe 17 installed horizontally just below the ridges of the soil 15. Both the heat radiating pipe 16 and the underground heat exchange pipe 17 are trunks. It consists of a pipe and a branch pipe.

In the above implementation model, the cultivation floor 10 has an effective cultivation floor area of 400m ² (20m x 20m rectangle), and when the cocoons and cocoons are arranged alternately at intervals of 0.5m, 20 rows of 20m long cocoons and cocoons are provided. You can do it one by one.

  The trunk pipe of the heat radiating pipe 16 is a circulation pipe composed of a down pipe flowing out so as to circulate with the cushion tank 13 and an up pipe flowing in. The trunk pipe of the underground heat exchange pipe 17 is a heat exchanger on the ground heat source side of the heat pump 14. The circulation pipe is composed of a down pipe that flows out so that the antifreeze circulates and an up pipe that flows in. The total length of the radiant pipe trunk pipe and underground heat exchange pipe trunk pipe shall be 40 m respectively.

  The branch pipes of the radiating pipe 16 are connected to the upstream and downstream pipes of the trunk pipe by connecting two rows of ridges horizontally in a U shape to a depth of 50 cm, and branch pipes are installed under all the armpits as a unit. . The total length of the radiating pipe branch pipe is 400 m. The branch pipes of the underground heat exchange pipe 17 are connected to the upstream and downstream pipes of the trunk pipe by connecting two rows of ridges horizontally in a U-shape to a depth of 1 m, and this is connected as a unit to all the armpits. Is installed. The total length of the underground heat exchange pipe 17 is 400 m.

  FIG. 3 shows the concept of heat transfer for the heat source ground temperature compensation type geothermal heat pump system by the horizontal two-layer installation method in the soil of the heat radiating pipe 16 and the heat exchange pipe 17 including the cultivation facility 10 of the present invention. This is an expression that is used to approximate the amount of heat transfer.

Standard heat transfer rate to the ground from the soil surface is ^{4kcal / h · m 2 · ℃} , standard heat transfer rate to the outside air from the facility wall and ^{3kcal / h · m 2 · ℃} . In winter, if the outside air temperature is 0 ° C, the facility temperature is 10 ° C, and the soil temperature is 20 ° C, the heat transfer from the soil surface to the ground surface is approximately 4 × (20-10) ° C × 400m ² = 16,000kcal / h is there. In order to make this a steady heat transfer amount, if the heat radiation efficiency from the heat radiating pipe 16 is supplied at 40 kcal / h · m per unit pipe length, the total heat radiation amount is approximately 40 × 400 m = 16,000 kcal / h. On the other hand, to make the heat transfer amount from the wall area of the facility 10 to the outside air 16,000kcal / h, the area of the heat transfer wall is approximately 16,000 ÷ 3 ÷ (10−0) ℃ = 540m ² , The amount of heat passing through the wall surface is prevented by the heat shielding curtain 11 and other methods (FCU 12 heating and the like).

  When the heat pump is operated with a standard coefficient of performance (COP) = 4, the heat exchange rate in the ground, which is the source of heat dissipation of 16,000 kcal / h, is 16,000 x 3/4 = 12,000 kcal / h in the case of heat collection. Heat exchange rate per length = 16,000 ÷ 400 m = 30 kcal / h · m = 35 W / m. This heat exchange amount can be regarded as the heat exchange amount corresponding to the minimum amount in a geological environment without a groundwater flow.

  Next, since the thermal conductivity of sandy and clay soils is approximately 1 kcal / mh ° C, the radiation heat of 35 ° C from the heat radiation pipe 16 below the root zone causes 40 kcal / h · m to be radiated to the cylinder by downward heat transfer. When heat is transferred to the ground, a ground temperature of about 20 ° C. is given at the depth of the underground heat exchange pipe 17.

  As can be seen from the above estimates, the average temperature of the outside air is 0 ° C with a heat release of about 35 ° C from the heat radiating pipe, constantly maintaining the root region temperature of 20 ° C and the facility temperature on the soil of 10 ° C. Can be cultivated in winter, and the ground heat exchange pipe is maintained at a ground temperature of approximately 20 ° C by downward heat transfer, and the heat pump COP = 4 has a ground heat exchange rate of 35W / It is a total system that can sufficiently obtain m.

(Appendix)
The present invention is described below.
1. (apparatus)
In a facility-cultivated soil, a heat dissipating pipe device that circulates tap water for cultivation in the vicinity below the root region of cultivated vegetables and flower buds is installed horizontally, and the antifreeze liquid is circulated near the subordinate portion of the heat dissipating tube device. An intermediate heat exchanger pipe installed horizontally and connected to an above-ground water-cooled heat pump, supplying appropriate heat (or cold) to the root area, and rising heat from the soil area into the facility (or (Cold heat) is supplied to vegetables, flower leaves, and stems, and heat is also collected from the ground by the heat (or cold heat) that is transferred downward from the radiator pipe to lower the ground temperature (or exhaust to the ground to increase the ground temperature). The amount of heat penetration between the roof and wall of a cultivation facility that has the effect of raising (or lowering) and recovering the temperature around the underground heat exchanger pipe, and is made of a material with poor outside air temperature and heat insulation ability To adjust from the ground to the open air In order to ensure effective heat transfer, heat radiation curtains or heat pumps inside the facility from the heat pump (or cooling) are incorporated as an auxiliary function, and two horizontal layers in the soil of the heat sink and heat exchanger Heat source ground temperature compensation type underground heat pump system by installation method.
2. (Method)
Arrange the persimmons and persimmons at appropriate intervals on the soil surface of leafy vegetables, fruit vegetables, and flowering plants with a suitable floor area of normal scale, and close to the root area of the vegetable (within 30 cm depth from the persimmon surface) Heat pump cushions by connecting branch pipe heat radiating pipes that circulate tap water under the lower arm (about 50 cm deep from the soil surface) horizontally in series (two or four lines) in series and radiating pipe trunk pipes On the other hand, the branch pipe underground heat exchange pipe that circulates the antifreeze liquid under the dredging about 1 m deep from the soil surface is horizontally arranged in two rows (or four rows) in series to form a heat exchange pipe trunk. Combined and connected to the heat exchanger (or condenser) in the heat pump, the antifreeze flowing in the underground heat exchange pipe at a constant flow rate is collected by heat transfer between adjacent underground ( (Or waste heat) and evaporate the antifreeze liquid heated (or cooled) by the heat pump After introducing into the heat exchanger (or heat exchanger as a condenser) and gasifying (or liquefying) the circulating refrigerant of the heat pump from the liquid, the high-temperature and high-pressure gas (or the expander) with an electric compressor In the low-temperature and low-pressure liquid), and through the heat exchanger (or heat exchanger as an evaporator) and the cushion tank in the heat exchanger (or heat exchanger as an evaporator) as a condenser Underground soil adjacent to tap water that radiates heat (or collects heat from tap water) and raises (or cools down) the tap water circulating between the radiator pipes and flows at a constant flow rate in the heat dissipation pipe Heat (or endothermic) by heat transfer to and from the soil, the root zone temperature of the upper soil of the heat radiating pipe is raised (or lowered) to an appropriate temperature, and the heat transfer to the air in the cultivation facility through the soil surface is steady Suitable temperature for the stems and leaves of vegetables and flowers In order to maintain it, a curtain is installed on the roof and wall of the cultivation facility, or air heating (or cooling) inside the facility from the heat pump is incorporated as an auxiliary function, and the underground heat exchange piping area below it from the radiator pipe A heat radiating tube and a heat exchanger characterized by a method having a heat source environment compensation function that recovers the underground temperature lowered (or increased) due to heat collection (or exhaust heat) by transferring heat to Heat source ground temperature compensation type geothermal heat pump system by horizontal two-layer installation method in soil.
3.
The heat (or cold heat) radiated from the horizontal heat radiating piping system in the ground is transferred directly to the root area of vegetables and flowers by transferring heat through the hydrous soil, and then transferring heat to the ground surface. Heating (or cooling) the air and transferring heat from the air to the leaves and stems is a heat supply method that is not wasteful to the cultivated vegetables and florets. Both the heat transfer mode of the heat (or cold) to be transferred is a cylindrical radial transmission from the radiator pipe to the upper root region and from the radiator pipe to the lower underground heat exchanger piping device. It is expressed by a relatively simple heat transfer model depending on the combination of heat, so it is easy to control and save energy, and heat source ground temperature compensation type ground heat by heat radiation pipe and heat exchanger horizontal two-layer installation method in the soil Heat pump system.
4).
A system that combines a horizontal heat-dissipating piping system and an underground heat exchanger piping system installed below the floor of a cultivation facility with a water-cooled heat pump on the ground. By selecting one of the combination of the evaporator and the condenser, or the combination of the condenser and the evaporator, the supply of hot or cold can be supplied corresponding to changes in the cultivation environment, etc. A heat source ground temperature compensation type geothermal heat pump system by horizontal two-layer installation method of heat radiation pipe and heat exchanger in the soil.
5.
A system that combines a horizontal heat-dissipating piping system installed about 0.5m below the floor of a cultivation facility and a ground heat exchanger piping system installed horizontally about 1m below the floor with a water-cooled heat pump on the ground. Therefore, construction is possible with simple and inexpensive civil engineering machines and methods without the need for borehole excavation for underground heat exchange, and construction is possible as part of the foundation of cultivated soil The heat source ground temperature compensation type geothermal heat pump system by the horizontal two-layer installation method in the soil of the radiator pipe and heat exchanger.

  The preferred embodiments of the present invention have been described above. However, the embodiments are not limited to the above, and various modifications and combinations can be made without departing from the gist of the present invention.

10 Greenhouse (cultivation facility)
11 Thermal barrier 12 FCU (fan coil unit)
13 Cushion tank 14 HP (Heat pump)
15 Soil 16 Piping for heat exchange 17 Piping for heat supply

Claims (4)

In the heat supply system of the cultivation facility that cultivates the cultivation target in the soil,
A heat pump,
The heat pump has a heat exchange pipe for exchanging heat with underground heat, and a heat supply pipe for supplying heat generated by the heat pump to the cultivation facility,
The heat supply pipe is horizontally arranged below the root area of the cultivation target, and the heat exchange pipe is horizontally arranged below the heat supply pipe,
In the heat exchange pipe and in the heat supply pipe, an antifreeze is circulated to exchange heat with the heat exchange pipe and the periphery of the heat supply pipe.
Compensating the temperature around the heat exchange pipe with heat supplied from the heat supply pipe;
A heat supply system for a cultivation facility characterized by that. A cushion tank was further provided between the heat pump and the heat supply pipe.
The heat supply system for a cultivation facility according to claim 1. Further provided a fan coil unit for supplying auxiliary heat in the cultivation facility,
The heat supply system for a cultivation facility according to claim 1 or 2. The heat exchanging pipe is arranged almost directly under the straw in the cultivation facility,
The heat supply pipe is arranged almost directly below the ridge in the cultivation facility,
The heat supply system for a cultivation facility according to any one of claims 1 to 3, wherein the heat supply system is a cultivation facility.

Images