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Shanxi Province plateau cold area formally adopted the achievement of identification by the relevant departments

Beijing Greenhouse2012/12/4 9:57:23
 
Research project by our company and Shanxi Academy of Vegetable Research Institute of the bimodal (SF type) solar greenhouse built local standards in Shanxi Province plateau cold area formally adopted the achievement of identification by the relevant departments. The achievement of comprehensively applicate a number of technology, like new steel frame, the honeycomb concrete block brick and plastic film covering, that the greenhouse temperature can improve from 5 degrees Celsius to 12 degrees Celsius, and end the history of the the plateau cold area can not use solar greenhouse growing vegetables .
 
First,plateau cold area SF solar greenhouse
Set zippered plastic no drops film within the insulation device at the bottom of the scarp roof, and add the honeycomb regenerator made ​​of aerated concrete block in the building envelope inside, which makes an arched plastic film greenhouse, referred to as the SF Sunlight greenhouse. The greenhouse without heating is capable of producing thermophilic vegetables in winter in cold regions.
1, Azimuth of the greenhouse
The angle between the ridge line of the greenhouse and the meridian direction of the greenhouse construction location.
2, skeleton
Building structures in the greenhouse that support the roof and various loads, including the steel arch and the tie rod. The steel arch is a arcuate member of the greenhouse roof skeleton which configurates in transverse direction (perpendicular to the ridge line). The tie rod is a member of the greenhouse roof skeleton which configurates in longitudinal direction (parallel to the ridge line) and superposed couple with the steel arch vertically.
3, Minimum height of operating 
The height of the lowest point of skeleton above indoor, 0.5m from the frontier to the ground.
4, The height of the ridge 
Vertical height between the highest point of the  greenhouse back roof and the indoor horizon.
5 ,Span
Greenhouse back wall indoor base and the horizontal distance between the front roof base.
6, The length
The length of the greenhouse along the ridge direction,or the distance between the east wall inside and the west wall inside of the greenhouse.
7 ,Space
The distance between the two greenhouse.
8, Angle of the front roof 
Greenhouse cross-section of the angle between the tangent of the connection of the intersection of the surface daylighting roofing forefront with the ground and the ridge point and ground planes.
9, The elevation of back roof
The angle between the inner surface and a horizontal plane in the back slope.
10, Indoor design temperature
Minimum air temperature is set according to the level of greenhouse heating.
11, Inside thermal screen
The zippered plastic film set below the front roof.
 
Second, the structural design
1, The design requirements
Greenhouse structural design load shall comply meet the requirements of GB/T18622-2002, capable of carrying the wind speed at maximum 0.45kn / m2 (kn: force units) and the snow thickness at 0.35kn / m2, the crop hoists can reach 25kg / m2.
In the coldest season, 5 am to 6 am,  temperature in the greenhouse should not be less than 8 ℃. Sunny weather in winter, when the outside temperature is below -26 ℃, greenhouse indoor minimum temperature should be maintained at higher than 8 ℃, the temperature at the 10cm depths under the ground surface should be maintained at above 20 ℃.
Sunny noon on the winter solstice, light intensity in the 1m height level of the greenhouse central should reach 45,000 lux. Within two hours before and after noon sunny winter greenhouse average surface direct light transmittance should be not less than 60%.
2, Structure type
Greenhouse structure: the front roof has no pillar and set "几" section steel as a skeleton of brick and concrete steel-framed structures.
Wall structure: the wall using heterogeneous composite structure, the inner surface of the wall made into honeycomb wall. The order from the inside to the outside is 240mm aerated concrete block  +240 mm brick wall +100 mm polystyrene foam board +120 mm brick wall. Masonry structure should be designed to meet the GBJ3.
The operation room should rely on the one side of the greenhouse building, the area, the quality requirements need to be designed in accordance with local realities.
3, The structure size
The length of the the complete circuit greenhouse length is 60m ~ 100m.
The net span greenhouse is 7m ~ 8m appropriate.
The ridge high of the greenhouse to around is 3.8m appropriate.
4, The front roof arching
The front roof arched "几"-shaped steel frame, the frame spacing is 1m.
5, Elevation angle of the back slope
Elevation angle of the back slope is 340 ° ~ 430 °.
6, Angle of the front roof
Angle of the front roof is bigger than 280 °.
7, Height of the back wall 
The inside of the back wall is not heigher than 2.6m.
 
Third, Building materials
1, The general requirements
The selection of materials for greenhouse construction should meet the relevant national standards.
2, Skeleton material
The skeleton select 50mm “几”-type steel or other material of not lower than the performance of the skeleton. Skeleton and connections includes: the scarp slope column feet, the scarp slope arch rod, the back slope arch rod, tie rods, back slope purlins, roof beams, the platen of the roof, the inner package of the roof, roof package and so on.
3, Envelope materials
Wall materials
The main material is aerated concrete blocks, sintered common brick, and benzene board. The size of aerated concrete block: 240mm × 240mm × 200mm. The insulation layer use 100mm thick, bulk density of 10kg/m3 ~ 22kg/m3 polystyrene foam board.
The back slope material
The material covering the back slope of the greenhouse is the 960 composite colorful plate, on-board 0.4mm thick, the lower board 0.3mm thick, polystyrene board 100mm thick, and then set up the waterproof layer. Or using wood, benzene board, felt paper, waterproof coating.
4, day lighting cover material
The material should use multi-purpose agricultural polyvinyl chloride, vinyl acetate film that adopted a low temperature resistance, be anti-aging, no drops, opaque good, and should meet the requirements of GB/T2472 provisions.
5, the outer insulation cover material
The greenhouse insulation materials should use curtain or heat preservation quilt.
 
Fourth, the location and layout
1, the greenhouse site
Terrain
The greenhouse should be built on the open terrain, well-drained, no shady 30m-near areas such as tall trees and buildings in the east, south and west side. Avoid the wind gap, so as not to suffer the destruction of the strong winds, while improving the thermal insulation effect of the greenhouse also.
Site conditions
The groundwater level blows 3m, soil thickness is more than 80cm, fertile soil and irrigation is convenient, good water, low salinity, and to comply with the pollution-free agricultural production and environmental quality requirements, around no "three wastes" pollution around.
Environmental conditions
Convenient transport facilities, electricity, water supply.
2, pitch between front and rear greenhouse 
Distance between the front and rear greenhouse, should be designed that the shadow of the front row of greenhouse does not affect the rear greenhouse lighting on the winter solstice. In the plain areas, the most reasonable distance between the north and the south two greenhouse should not be less than the value calculated by the following formula.
L=(H+0.5)/tgα×cosβ-(L1+L2)  in formula:
L——Greenhouse spacing, the unit is m;
H——The greenhouse ridge, unit is m;
α——Sun elevation angle on the winter solstice,  local 10 o'clock;
β——The local solar azimuth 10:00 on the winter solstice,;
L1——Length of greenhouse slope projection, unit is m;
L2——Width of greenhouse back wall, units is m.
3, construction bearing
Greenhouse should face south and extend east and west (these are advantageous to accept more solar heat in winter), and appropriate westward migration (this can increase the afternoon light intensity, which is beneficial to improve the indoor temperature at night), general for the local south by west 5 °.
 
Five, construction
1, Earthworks
Site preparation
According to the construction drawing, determine the bearing, operate land leveling, plug peg, set out, began to dig base tank. Put a solid Foundation with tamper. Cover with a 100 mm thick 3:7 dust, then place a 100 mm thick cushion layer of C15 plain concrete.
2, Build barrettes
Greenhouse foundations was built using sintering common brick, M7.5 cement mortar masonry. The foundation covers 100 mm thick polystyrene plate thermal insulation layer outside.
3, Build walls
With aerated concrete block, sintering common brick and M7.5 cement mortar masonry build a 750 mm thick sandwich wall. Exterior wall 120 mm for retaining wall heat preservation, the surface of the wall plaster with twenty mm thick 1:3 cement mortar, to enhance the outer wall heat preservation performance; Interior wall is 240 mm thick aerated concrete block + 120 mm heat storage bearing wall; Sandwich layer is regenerative thermal insulation layer, width of 120 mm, filled with 100 mm thick polystyrene board, heat insulation, and blocking the external heat transfer.
4, Cold-proof ditch
In front foot of the solar greenhouse, dig a groove whose depth is not lower than the local permafrost thickness, width 30 cm, length is the same to the greenhouse length, cover the old plastic film around in the groove, and then fill in the timber, leaf, broken straw, wheat straw, corn stalk, packing encase, in order to prevent the rain water seeping into the packing, reduce the heat preservation effect, and then buried soil sureness, make it above ground level fifty mm, and high in the north and low in the south into slope shape, in case  some of the rain greenhouse front roof infiltration, reduce exposure effect.
 
Six, fix up
1, Framework fixing up
In casting the 240 mm thick reinforced concrete beam of the front and back wall, the construction requires embedded iron parts and hook.
For reinforced concrete beam curing, set out, and determine the front and back wall arch column foot welding position.
According to the requirements, after advanced assembled good arch on the ground in capacious and corresponding weld fluctuation beam embedded parts. After the adjustment, screw the scarp and back slope arch connection and diagonal rod. Then put on slope purlines. Finally setup the tie rod.
Ensure that each joint screwed in the whole installation process.
2, The back slope installation
First fix the ridge inside gusset plate to arch shelf with drill tail nail, and then install choir steel, fix with hex head drill tail nail to the frame, seal the color steel plate tap using the nails.
3, scarp slope cover
Greenhouse scarp slope covers by film, two heat preservation inside and outside.
In the roof of the mouth plate front, east and west end, along the scarp slope arch, fixed a ring hot dip galvanizing card slot with drill tail nail. Prior to the determination slope vent position and width, fixed up and down two card slot. Install insect nets and the former under the slope along the small piece of fixed film. Before installing the greenhouse slope whole large film, choose calm weather to buckle membrane. The width of the film should be more than roof 1.2 m, length should be more than 1 m, all things wall around should be secured. Skeleton between put a squeeze film line.
After installing slope film, squeeze film line and the thermal insulation, put the ridge outsourcing parts on choi steel to seal.
4, Built-in cover
Greenhouse built-in cover is built by steel wire rope support frame and manual film system composition. Wire rope support frame is to use 5 mm diameter of the wire rope end fixed in the inside of the north wall hook, around the middle of the road longitudinal rod, the other end fixed scarp slope ring beam hook inside the greenhouse things direction spacing 1.5 m arrangement. Manual film device is built by 0.15 mm long life without dropping film, card slot card spring, hot dip galvanized 6 for roll film shaft and hand chain film device composition, divided into two system called the front film and upper side film.