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Local standards of constructing technology of the greenhouse in area of shanxi province has passed the identification of achievements.

Beijing Greenhouse2012/12/4 9:39:53

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 areaformally adopted the achievement of identification bythe 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 areacan not use solar greenhouse growing vegetables .

First,plateau cold areaSFsolar greenhouse

 Set zippered plastic no drops film within the insulation device at the bottom of the scarp roof, and add the honeycomb regenerator made ​​ofaerated 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 ofthe greenhouse
 The angle between the ridge line of the greenhouse and the meridian direction of the greenhouse construction location.

2, skeleton
Building structuresin 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, Minimumheight of operating

 Theheight of the lowest point of skeleton above indoor, 0.5m from the frontier to the ground.

4, The height of the ridge
 Vertical heightbetween 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
 Thelength 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 thefront 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, Indoordesigntemperature
 Minimum air temperature is set according to the level of greenhouse heating.

11, Inside thermal screen
 Thezippered plastic film set below the front roof.

Second, thestructural design

1, Thedesignrequirements
 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, Structuretype
 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 intohoneycomb 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, Thestructuresize
 The length of the the complete circuit greenhouse length is 60m ~ 100m.
 The net spangreenhouseis 7m ~ 8mappropriate.
 The ridgehigh of the greenhouse to around is 3.8m appropriate.

4, The frontroofarching
 The front roof arched "n"-shaped steel frame, the frame spacing is 1m.

5, Elevation angle of the back slope
 Elevation angle of the back slope is340 ° ~ 430 °.

6, Angle of the frontroof
 Angle of the frontroof isbigger than280 °.

7, Height of the back wall
 The inside ofthe back wall isnot heigher than2.6m.

Third, Building materials

1, The general requirements
 The selection of materials for greenhouse construction should meet the relevant national standards.

2, Skeletonmaterial
 The skeleton select 50mm “n”-typesteel 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 lightingcover 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, theouterinsulationcover material
 The greenhouse insulation materials should use curtain or heat preservation quilt.

Fourth, the locationandlayout

1, thegreenhousesite
 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 reargreenhouse
 Distancebetween 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,theunit is m;
 H——The greenhouseridge, unit is m;
 α——Sunelevation angle on the winter solstice,  local10 o'clock;
 β——The localsolar azimuth 10:00 on the winter solstice,;
 L1——Lengthof greenhouse slopeprojection,unit is m;
L2——Widthof 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 tothe 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 aeratedconcrete 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 footof 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 beamof 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.