Organic vegetable glass greenhouses have a large-span spire design, large indoor operating space, high greenhouse utilization, and good display effects, so they are generally used for large-scale sightseeing greenhouses, seedling greenhouses, flower markets, large shopping malls, or ecological restaurants.
The main beam of the glass greenhouse adopts truss beams, which have a strong load-bearing capacity. The roof is a triangular ridge to distribute the indoor light evenly. The main steel structure is made of hot-dip galvanized pipes, surrounded by hollow glass, and the top is covered with 5mm thick tempered glass. The greenhouse is equipped with an internal/external sunshade cooling system, fan wet curtain strong cooling system, anti-condensation system, skylight ventilation system, heating system, intelligent control system, mobile seedbed system, mobile sprinkler irrigation system, power distribution system, etc.
Before the foundation is designed, the geological data of the construction site should be carefully analyzed:
1. Site geological survey report (for important large-scale greenhouse projects)
2. Construction site test (for general projects)
3. Based on experience and reference geological data of nearby projects (for small projects).
When designing the foundation of the organic vegetable glass greenhouse, in addition to meeting the requirements of strength, it should also have sufficient stability and the ability to resist uneven settlement. The foundation connected to the support between the columns should also have enough space and space to transmit horizontal force. stability. The bottom surface of the greenhouse should be located below the frozen soil layer, and the heating greenhouse can consider the influence of heating on the freezing depth of the foundation according to the climate and soil quality. Generally, the bottom of the foundation should be more than 0.5 meters below the outdoor ground, and the distance between the top of the foundation and the outdoor ground should be greater than 0.1 meters to prevent the foundation from being exposed and adversely affecting cultivation. Except for special requirements, the distance between the top surface of the greenhouse foundation and the indoor ground should be greater than 0.4 meters. The embedded parts connected to the greenhouse steel structure are all set on the top of the foundation, and the design of the embedded parts is also an important part of the foundation design. The connection between the embedded parts and the superstructure mainly includes articulation, consolidation, and elastic connection. According to the different connection methods, the design and construction methods are also different, but all embedded parts must ensure a good connection with the foundation and ensure that the upper structure is transmitted The coming force is correctly transmitted to the foundation.
1. Independent foundation.
Reinforced concrete is usually used. In terms of the construction method, the independent foundation can be divided into two methods: full cast-in-place and partial cast-in-place. Full cast-in-place adopts the method of construction site support and integral pouring; part of the cast-in-place method adopts the method of foundation short column prefabrication and foundation cushion on-site pouring. The two methods can be selected according to specific conditions. The cast-in-place method has the characteristics of good integrity and low cost; some cast-in-place methods have a higher cost but fast construction speed, and the construction quality is easier to guarantee.
2. Strip foundation.
The masonry structure (brick, stone) is usually used, and the construction is also carried out by on-site masonry. A reinforced concrete ring beam is often set on the top of the foundation to install embedded parts and increase the rigidity of the foundation. In addition, the sidewall foundation can also be mixed with independent foundations and strip foundations. The bottom surfaces of the two types of foundations can be located at the same elevation or can be set at different elevations according to the bearing conditions and functions. The independent foundation bears the force transmitted from the bottom of the greenhouse column, and the strip foundation is only used as a part of the partition member. Precautions for foundation construction. During foundation construction, the correctness of the column height and axis position should be ensured. The equipment, pipeline openings, and installation should be buried in time. It is strictly forbidden to gouge after construction to damage the foundation.
3. Water curtain side window system
Wet curtain side window form: aluminum alloy side-opening window, wet-curtain side window height: 1.5 meters, the rack and pinion top hanging window is electrically opened in summer, and can be closed to keep warm in winter. The opening angle can be large or small to meet the design requirements, and the mechanism runs smoothly, with consistent steps, and no abnormal noise. When the window is closed, there is no gap between the sealing strips of the window and the window, and there will be no excessive pressure on the window ledge and the window; the connection of the window opening connector is firm and reliable, and there is no relative position sliding. All relative transmission parts adopt lubrication measures and preventive measures. Rust measures.
4. Fan wet curtain cooling system
The wet curtain and fan system of the organic vegetable glass greenhouse are a means of forced cooling of the greenhouse in summer. The wet curtain fan cooling system uses the principle of converting sensible heat in the air into latent heat when water evaporates to cool down. The amount of water evaporated is proportional to the difference in saturated vapor pressure of the air. The drier the air and the higher the temperature, the greater the cooling rate of the air passing through the wet curtain.
Working principle: The wet curtain is installed on the gable or sidewall at one end of the closed greenhouse, and the fan is installed on the gable or sidewall at the other end. When the fan is exhausted, negative pressure is generated indoors, and when the outdoor unsaturated air is forced to flow through the porous wet surface of the wet curtain, a large amount of sensible heat in the air is converted into latent heat, thereby forcing the dry bulb temperature of the indoor air to drop by 4 to 12°C. Continue to introduce indoors for heatstroke prevention and cooling.