JP2013116096A - Agricultural pipe house installation type solar heat heating system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage type solar heat collector, capable of resolving detects such that a conventional solar heat collector of a solar heat heating system for an agricultural house is expensive and uneconomic, and even if the solar heat collector can be inexpensively installed in the house, it is poor in efficiency since 1/3 of the cultivated area is used as the installation area.SOLUTION: The system includes a flat plate solar collector capable of collecting heat from both surfaces thereof, which is provided horizontally at a vertically middle position on the north side inside the agricultural house installed to lie east and west; and a reflector provided to guide solar heat beams to the collector from the upper side and from the lower side to collect heat. The heat is stored in a soil heat accumulation layer within a fortified soil layer. According to this, the heat collection amount of solar heat per heat collection area of the collector is increased, and the installation space of the collector is suppressed to 20% or less of the cultivated area.

Description

    The present invention relates to a solar heat collector, and more particularly to a system for efficiently collecting solar rays incident on a facility horticultural house on the north side of the house to make a heat source for heating the house.

Hot air heating by kerosene and heavy oil-fired boilers is the mainstream for heating the facility horticulture house, but CO ₂ emission reduction is currently required and the use of natural energy is required.
The performance of the solar collector is defined in JISA4112 “Solar collector” [Non-patent document 1], and the test method is described in JISA4125 “Solar collector heat collection test method” [Non-patent document 2]. Yes.
[Patent Document 1] discloses a solar collector using a transparent plastic as a new solar collector. However, the disclosed device is portable for camping and is not practical for long-term use.

[Patent Document 2] reports a solar water heater using a plastic heat exchanger. However, this is for ordinary houses and is not efficient when applied to a facility horticulture house.
A mechanism that can efficiently collect light rays that are not directly involved in photosynthesis with sunlight incident on a facility horticultural house on the north side of the house and that can store the heating load of the house is effective.

[Patent Document 3] reports a heat collection system using a plastic film proposed by the present applicant. However, the efficiency as a heat collector is good, but because it is constructed outside the facility horticultural house, it is expensive to make wind and pressure resistant, snow resistant structure, and the heat medium on the heat collecting system is once received in the receiver tank in the basement, A falling plumbing system for circulation control is required, and the system as a whole is not cost-effective, making it difficult to be an inexpensive heating source for agricultural products.
Generally, the value of a solar heating system is not evaluated unless ten times the fossil fuel used in one season of a facility horticultural house can be recovered, that is, less than 10 years.

  JP 5-79706   JP2007-64589   Japanese Patent Application No. 2009-035884

  JISA 4112-1995 "Solar collector"   JISA4125-2000 “Testing method of solar collector heat collection performance”

  It is an object of the present invention to collect all the sunlight rays incident on a facility horticultural house without escaping outside the house and use it as a heating heat source.

Because the heat collection mechanism is installed inside the house, it is necessary to reduce the cultivation area by cultivating land for the installation. If a normal heat collector is installed inside, the inclination angle is fixed within the range of 45 ° to 60 °. Therefore, in the case of a standard pipe house in Hokkaido of 7.2m wide, about 1/3 is taken and only 2/3. Can't grow. If the width of the heat collection surface is 1/6 of the width of the house when the heat collection surface is placed horizontally and the reflective film is installed at the top and bottom so that all incident light enters the horizontal heat collector, conventional heat collection The amount of heat collection is higher than that of the oven. Therefore, the installation area is halved. See FIG.
The collected hot water passes through a resin pipe embedded in the cultivated basement and circulates the collected hot water to store heat in the underground heat storage layer. This heat storage system was reported at the 8th presentation of the Japan Solar Energy Society in 1982 and was manufactured by the applicant. (Lectures 165-168)
This pipe is a closed pipe system, and expansion due to temperature rise is not a metal heat collector, and when a resin solar heat collecting bag is used, it absorbs due to its shape change and does not require an expansion tank.
The material of this heat collection bag is a batch in which carbon black that absorbs sunlight and materials that absorb ultraviolet rays are absorbed into a general-purpose resin, and a filler that selects the wavelength that reflects in the long wavelength range but reflects in the short wavelength range Make resin and distribute to base resin at 5%.
The lower part of the heat collection bag is constructed of a metal plate and supported by a heat insulating material, and a selective absorption film is attached to the lower side of the metal plate. The upper surface of the heat collecting bag and the lower part of the metal plate are covered with a permeable film to prevent air convection.

The plastic heat collecting bag of the present invention is loaded on a metal plate and covered with a permeable film, and there is no inclination between the permeable film and the heat collecting film. There is little heat transfer loss just by generating a small vortex. Also, since the heat collecting surface of the lower metal plate is heated from the lower side, the upper part is hot and the lower part is cold, air convection does not occur, convective heat transfer loss does not occur in the static air layer, Compared with the conventional type shown in No. 3, the heat collection amount is 700/485 = 1.44, 1.4 times that of a normal flat plate heat collector, and the heat collection amount is large. Moreover, since it is installed in the house, the temperature difference between the heat collection temperature and the outside air is small, and therefore the heat collection efficiency is high. See FIG.
By placing it horizontally, the convection heat loss, which is the largest element of the three major heat loss elements (radiation, conduction, convection), is reduced. Pumps and receiver tanks are no longer required. Heat collecting bags can be manufactured thinly with an extruder, and the size of each bag can be continuously produced with a width of 1 m. It can be unitized by cutting it into 10 m, which is convenient for carrying, and a farmer can connect five 10 m scrolls. It is easy to assemble a solar collector in a standard Hokkaido house.
There have been various collectors made of elastomer in the past, but there is no other example of a large collector with a film thickness of 0.5 m / m and one unit of 50 m ² or more.

It is a house installation schematic diagram of the plastic film heat collecting bag system which concerns on one Embodiment of this invention. Comparison of heat collection efficiency characteristic diagrams of conventional elastomer collectors and metal inverted flat plate collectors Comparison table between the amount of heat collected from the 1m ² collector installed in the house based on the amount of solar radiation announced by the Japan Weather Association in Sapporo and the amount of heat collected from the conventional collector 1.8m ² An example of a solar heat collecting bag A is a plan view B is a cross-sectional view along line aa

BEST MODE FOR CARRYING OUT THE INVENTION

  Embodiments of the present invention will be described below in detail with reference to the drawings. This description is for explaining the present invention, and is not intended to limit the technical scope of the present invention by this description. Various modifications may be made without departing from the technical scope of the present invention. Is possible.

FIG. 1 is a schematic view showing an outline in which a resin solar heat collecting bag system according to an embodiment of the present invention is installed in a house.
As shown in FIG. 1, the resin solar heat collecting bag is horizontally loaded on a metal plate with a selective absorption film, the metal plate and the bag are in close contact, and the member supporting the metal plate is an EPP. It is placed on the pipe mount via heat insulation.
Sun rays input from the south side are directly or once reflected and absorbed by the heat collection bag. Scattered light and sunlight incident on the lower level are reflected by the lower reflection film, absorbed by the metal plate, and heat the water in the heat collecting bag. Therefore, the heat collecting bag is heated from two directions, from above and from below. The heat collecting bag is a plastic film with a thickness of 0.5mm and is connected in a watertight manner as a unit of 1m in width and 10m in length. There are 9 partition lines in 1m in width and 10 channels in width 9cm are constructed. However, they are arranged so as to merge at both ends, and each unit has a structure in which 10 L of water enters in a flat position. An automatic air vent valve is provided in the uppermost pipe.
As the water temperature rises, the water in the sealed piping system expands, and the expansion of the heat collecting bag is changed into a spherical shape, so that the expansion is absorbed and an expansion tank is not required.
When the temperature of the heat collection bag became 7 ° C higher than the temperature of the soil layer, the circulation pump was activated and circulated and collected heat until the temperature difference between the soil 60cm underground and the heat collection bag became 4 ° C or less. Solar heat is stored in the soil layer. It is good when it is sufficient for heat dissipation at night, but it is better to widen the heat collection bag for the shortage. When the temperature of the heat collecting bag becomes 3 ° C. or lower, the circulation pump is operated to prevent the heat collecting bag from being frozen by the ground temperature of 60 cm underground.

The solar heat conversion efficiency of solar collectors currently in widespread use is 35% on average, and the price is also expensive because it is made of metal and glass. On the other hand, the heat collecting mechanism invented this time can collect heat from both sides, the amount of heat collection increases by 40%, and when collecting heat with a film heat collecting bag, the price is very low and can compete with the heating cost of kerosene. It ’s here. This heat collection system becomes widespread as the global movement to reduce CO2 emissions increases.

1 Agricultural pipe house 2 Heat collecting plate upper reflective sheet 3 Heat collecting plate lower reflective sheet 4 Heat collecting bag 5 Heat collecting bag lower heat collecting plate 6 Heat storage pump and controller 7 Branch header with adjusting valve in underground heat storage layer 8 Underground piping 9 Thermal storage tank 10 Heat collection bag 11 Permeation film

Claims (3)

  A solar heat collector that absorbs solar heat and heats water, and a solar heat storage system that constitutes a circulation pump and piping system that supplies the soil heat storage layer, the solar heat collector is a facility horticultural house installed in the east and west Install a heat collector that can collect heat horizontally from both the front and back in the middle of the north side of the house, and install a reflector so that sunlight can enter the heat collecting plate inside the upper house and the lower house respectively. Solar heat collection system provided.   The heat collector that can collect heat from both the front and back surfaces is a heat insulating layer that is loaded with a bag-shaped heat collecting bag formed by extrusion molding of general-purpose resin on a metal plate with a selective absorption film on the lower surface, and a transparent film is spread on the top. The solar heat collection system according to claim 1, wherein the solar heat collection system is formed by forming a static air layer below the heat collection plate by lowering the end of the heat collection plate from both ends of the north and south sides. The collector that can collect heat from both the front and back sides is a metal plate with a selective absorption film on the bottom, three types of thermoplastic films of the same type: natural film on the lower side, solar heat absorbing film on the middle, and transmission film on the upper side. 2. The solar heat collecting system according to claim 1, wherein a heat-welded pouch-shaped heat collecting bag is loaded.