The challenge of ultralow temperature anchorage re

The challenge of ultra-low temperature anchor research and development of Liugong ovim company ultra low temperature

the challenge of ultra-low temperature anchor research and development of Liugong ovim company ultra low temperature

China Construction machinery information

Guide: at the end of March 2013, the national construction engineering quality supervision and Inspection Center organized LNG ultra-low temperature anchor static load test in ovim company test center. The OVM ultra-low temperature static load test system was used in the test, and the ovim ultra-low temperature anchor was tested. The test results fully met the requirements of three passes of the standard, and successfully passed the test. And

at the end of March 2013, the national construction engineering quality supervision and Inspection Center organized the LNG ultra-low temperature anchor static load test in the test center of ovim company. OVM ultra-low temperature static load test system was used in the test, and ovim ultra-low temperature anchorage was tested. The test results fully meet the standard requirements and passed the test successfully. The ultra-low temperature anchorage produced by a foreign company failed to pass the test

what is ultra-low temperature? What is LNG

lng is the English abbreviation of liquefied natural gas. The gaseous natural gas under normal temperature is treated at minus 162 ℃ to form liquefied natural gas, and the volume of natural gas is reduced by about 600 times after ultra-low temperature treatment

as a large energy country, China needs to import LNG from abroad and transport it back to China through super LNG ships. Generally, LNG storage tanks are used for storage. This kind of storage tank is divided into inner tanks and outer tanks. Heat insulation materials are filled between the inner tanks and outer tanks. The inner tanks are made of low temperature resistant metal to store LNG directly. The outer tanks are made of prestressed concrete, which plays a supporting and protective role for the inner tanks and ensures that LNG will not leak out in case of accidents in the inner tanks. To prevent leakage of LNG outer tank, steel strands are used to clamp the tank tightly. The function of prestressed anchorage is to "tie" the steel strands that clamp the tank tightly. Before 2009, there was no anchor that met the requirements of LNG ultra-low temperature in China, while the price of ultra-low temperature anchor in foreign countries was high and the technical service was not timely. In order to get rid of the dependence on foreign products, the domestic market has put forward the urgent requirement of localization of ultra-low temperature anchorage

take the lead in prestress and resolutely shoulder the heavy responsibility

ovim company, as the leader of the domestic prestress industry, resolutely shouldered the heavy burden, and it is its bounden duty to develop ultra-low temperature anchors that meet the requirements of LNG ultra-low temperature. In 2005, it established a project team to carry out the special development of "15 ultra-low temperature structural anchorage system", and strive to complete the project in four years

as a professional prestressed enterprise, ovim company has rich experience in the design, production and construction of prestressed system, but has no reference experience in low-temperature test and low-temperature materials, and no domestic enterprise has conducted ultra-low temperature test with strict requirements. According to the requirements of foreign ultra-low temperature anchorages, the anchorages should be tested under the ultra-low temperature environment of minus 196 ℃, and the test results should meet the standard requirements. After the establishment of the project team, it encountered a problem: what materials are used to process the anchorage to meet the ultra-low temperature requirements? How to reduce the temperature to minus 196 ℃ during the test

under the leadership of zhuwanxu, deputy chief engineer of the project team leader, the project team is divided into two ways, one is to find low temperature resistant materials, and the other is to consider ultra-low temperature test. Through searching the data, the members of the project team learned that the temperature can be reduced to minus 196 ℃ by using liquid nitrogen. The liquid nitrogen is packed in a special liquid nitrogen tank. How to extract the liquid nitrogen during the test? How is the test device insulated? How to test in ultra-low temperature environment? Problems about liquid nitrogen always haunt everyone. During that time, all the members of the project team thought about liquid nitrogen, and even some people talked about "liquid nitrogen" in their dreams at night. After comparing various methods, we carefully determined the scheme. After all, liquid nitrogen is zero. It also creates a new "partner" business model. Under the ultra-low temperature of more than 200 degrees, splashing on people is a very terrible thing. How to protect scientifically

we didn't flinch, dry

through the efforts of selecting excellent alloy structural steel in many ways, the project team has cooperated with a Research Institute of Aerospace Industry Corporation to develop a set of ultra-low temperature test system, but the purchase of such a system requires more than 800000 yuan. The company leaders make a decision on the spot and buy it! After careful preparation, ovim's ultra-low temperature test began in 2006. Wearing heavy protective clothing, the test personnel tensioned the steel strand to 80% of the breaking force according to the normal static load test procedure, and pumped liquid nitrogen into the test tank with a pump

after many failures, summaries and improvements, in December 2008, witnessed by many experts in the LNG field at home and abroad, the ultra-low temperature anchor developed by ovim successfully completed the ultra-low temperature static load test of 19 hole anchor at minus 196 ℃ according to the most stringent international standards. The test results show that the ultra-low temperature anchor developed by ovim company fully meets the ultra-low temperature requirements of LNG storage tanks and can be safely applied to LNG storage tanks

zero breakthrough of domestic anchors in LNG field

it is difficult to take the first step of using domestic ultra-low temperature anchors. In order to bring the homemade ultra-low temperature anchorage to the market, the leaders, business managers and technical directors of ovim company have repeatedly visited the relevant LNG construction units for publicity and recommendation, and invited relevant personnel to visit the company and witness the test. On November 30, 2011, the Shandong LNG project management department of Sinopec 3 and natural gas company with peak memory hosted an expert review meeting on "localization and application of prestress system of Sinopec Qingdao LNG concrete storage tank" in Beijing. At the meeting, experts fully affirmed the 15 ultra-low temperature anchoring system of ovim. Therefore, on the 15th day of 2012, the ultra-low temperature anchoring system officially entered the LNG field in China, and was successfully applied in Shandong LNG storage tank project, realizing the zero breakthrough of anchorage in the LNG field in China

after years of efforts, ovim people have successfully challenged ultra-low temperature. The 15 ultra-low temperature anchor system developed by the project team has been applied to Shandong LNG storage tank project and Beihai LNG storage tank project, and some LNG storage tank projects are under negotiation. The OVM ultra-low temperature static load test system developed by the project team is the only ultra-low temperature static load test system in China at present, Zhuwanxu, deputy chief engineer of the project, participated in the preparation of the technical specification for the application of anchorages, clamps and connectors for prestressed tendons (JGJ), which included the requirements and test methods of ultra-low temperature anchorages in the specification, laying a technical foundation for ultra-low temperature anchorages in China