IGES (Initial Graphics Exchange Standard) is a general graphics data exchange standard, which has been widely used for data exchange between different CAD/CAM systems. But the inherent defect of IGES makes it difficult to use in the field of automatic programming. This article focuses on the automatic programming of holes processing. Entities were labeled with different entity number, on which the hole entity could be distinguished and extracted based. The intersection lines of hole and NURBS surface could be calculated by NURBS surface intersection algorithm. The redundancy of intersecting lines is a key problem. This article gives an intuitive treatment.
Based on the research of 472 heating boilers in different districts of Tianjin, statistical data of burning coal consumption, power consumption and heating quantity were obtained. From the angle of the primary energy consumption needed by unit heating quantity, energy efficiency of boiler in Tianjin was calculated. It's from 39kg/ GJ to 89kg/ GJ. Corresponding boiler efficiency is from 38% to 86%. Furthermore the average value of energy efficiency and boiler efficiency were confirmed, were 57kg/ GJ and 62%.According to the calculated result, the energy efficiency and boiler efficiency of district heating boiler in Tianjin is low, energy saving and reconstruction are encouraged.
The air conditioning system did not run as the design conditions in most of the time. Therefore, how to rationally adjust air parameters under part-load conditions caused by changes in the outdoor environment is an important issue, which is crucial to people’s comfort and energy systems. This paper introduces the part-load rate α to distinguish among different load-part conditions. And by taking the typical conditioned space of underfloor air distribution (UFAD) system in perimeter zone of New Tianjin Library as the object and using Fluent for simulation analysis, we get the conclusion that there is a maximum limit of supply air temperature and a minimum limit of supply air velocity under summer part-load conditions. For each condition, there is a set of optimal air parameters to make the indoor personnel achieve the most comfortable condition. Finally, we acquire this set of optimal air parameters by simulating and analyzing.
Based on the simulation of the air conditioning construction dynamic load and simulation calculation of air-source gas engine-driven heat pump (GEHP), the air-source GEHP air conditioning in winter, summer and the annual primary energy ratio are analyzed in simulation with the combination of a hotel building in Tianjin. Firstly, DeST software is used to simulate all-year hourly air conditioning load of the building. Then air-source GEHP simulation model [1] is used to calculate the annual hourly gas consumption and the amount of GEHP's gas consumption in winter, summer and a total year afterwards can be got. At the same time, by the analysis of waste heat recovery of gas engine-driven, primary energy ratio for air-source GEHP in Tianjin is given under the different waste heat recovery of winter, summer and the annual.
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