U-tube refers to a heat exchange tube shaped like a U, which is an important part of a U Type heat exchanger. Advantages of U-shaped tube: The U-shaped tube heat exchanger has only one tube plate, both ends of the tube are fixed on the same tube plate, the tube can be stretched freely, no thermal stress, and the thermal compensation performance is good; the tube side adopts double tube side, The process is longer, the flow rate is higher, the heat transfer performance is better, and the pressure bearing capacity is strong. The tube bundle can be drawn out from the shell, which is convenient for maintenance and cleaning, and the structure is simple and the cost is cheap. The disadvantage of the U-shaped tube is that due to the limitation of the radius of curvature of the bend tube, the arrangement of the heat exchange tubes is less, the innermost tube spacing of the tube bundle is relatively large, the utilization rate of the Tube Sheet is low, and the shell-side fluid is easy to form a short circuit, which is harmful to the transmission. When the tubes are leaked and damaged, only the U-shaped tubes at the periphery of the tube bundle are easy to replace. If the inner heat exchange tube is damaged, it cannot be replaced, but can only be blocked. Moreover, one damaged U-shaped tube is equivalent to two damaged tubes, and the scrap rate is relatively high.
U-tube,U Shaped Tube,Bundle Tubes,U Tube Bundle Guangdong Jiema Energy Saving Technology Co.,Ltd , https://www.heatexchangerjiema.com
In addition to the selection of cucumber varieties, the cultivation of cucumbers in the solar greenhouse in winter and spring is not only important for the selection of cucumber varieties, but also the continuous improvement of the cultivation techniques. It is very important to select good varieties, and to select good market according to market demand and to produce high quality fruits under low temperature conditions. Good varieties with strong disease resistance and premature aging are far from enough. Under the improvement of technology, various types of greenhouse climate control instruments also need to show their talents. For example, a carbon dioxide meter is the best instrument for analyzing the content of carbon dioxide in greenhouses.
Solar greenhouse greenhouse cucumber production in winter, the application of micro-spray irrigation under the membrane is the preferred high-efficiency, practical technology. The technology is easy to install, easy to operate, has obvious advantages of saving water, fertilizer, improving fertilizer efficiency, improving soil physical and chemical properties, increasing temperature, and lowering humidity. By using this technology, the water saving rate can reach over 50% in drought and half. Agricultural development in arid areas has broad prospects for promotion. The fertilization with water is applied to the fertilization to avoid the loss of fertilizer nutrients, which is conducive to the uniform absorption of nutrients and moisture by the crop, thereby increasing the utilization rate of the fertilizer. Can better maintain the physical and chemical properties of the soil, reduce the degree of soil acidification and salinization, and create a good soil environment for the normal growth of the crop. Can effectively improve the greenhouse temperature and temperature, according to tests show that, compared with the barren irrigation temperature increased 3} = 60C, the temperature increased by 1-} 0C, the relative humidity of the greenhouse decreased by about 23%, can effectively reduce the invasion of various pathogens Dyeing, prevention than the occurrence of various diseases.
In addition, it can also save the irrigation ditches in the shed and increase the number of planting plants. Therefore, through the application of under-film hose micro-sprinkler irrigation technology, it saves time and labor and saves water resources. The fruits of the produced vegetables are neat, the results are concentrated, the color is good, and the quality is excellent. The shed vegetables can increase income and reduce expenditures, 2000 yuan/ / 667mZo application technology, is on the side of the ridge of the cucumber seedlings, install the hose micro-irrigation facilities, after security, with a 70cm wide plastic film cover, the seedlings from the film out, seal the seedlings, and then With a diameter of 1cm steel Shun Miao ridge, 2 cm from the seedlings 5cm. In the future, we will drill holes on the stage once a month.
The control of water and fertilizer is an important technical measure in greenhouse cultivation, and the application of gas and fertilizer is also an important measure for the cultivation of this facility. The CO2 measurement instrument for the detection of indoor carbon dioxide content has the effect of timely replenishing gas and fertilizer, ensuring the growth and development of crops, and improving the yield and quality. Can not be ignored role.
Application of Carbon Dioxide Measuring Instrument in Cucumber Cultivation in Winter and Spring in Greenhouse
With the constant optimization and upgrading of the agricultural economic structure, people’s living standards have been continuously improved, and the promotion of facility cultivation techniques in our country’s rural areas has become more and more widespread. In the process of facility cultivation, we must not only do a good job in crop yields, but more importantly, ensure that agricultural products quality. After a period of practice, it can be proved that the application of new technologies in the production of cucumbers in the solar greenhouse in winter and spring can improve the product value of the products and achieve high-quality and high-efficiency cultivation effects.