Search results for: Zhongzhi Hu

Authors: Zhongzhi Hu, Jie Shen, Jiqiang Wang

Abstract:

A high precision aeroengine model is needed when developing the engine control system. Compared with other main components, the axial compressor is the most challenging component to simulate. In this paper, a compressor map optimizing tool based on the introduction of a modifiable β function is developed for FWorks (FADEC Works). Three parameters (d density, f fitting coefficient, k₀ slope of the line β=0) are introduced to the β function to make it modifiable. The comparison of the traditional β function and the modifiable β function is carried out for a certain type of compressor. The interpolation errors show that both methods meet the modeling requirements, while the modifiable β function can predict compressor performance more accurately for some areas of the compressor map where the users are interested in.

Keywords: beta function, compressor map, interpolation error, map optimization tool

Procedia PDF Downloads 267

Authors: Huihui Zhang, Zhongzhi Zhang

Abstract:

Coagulation/flocculation is regarded a simple and effective wastewater treatment technology. Chlorine-containing coagulants may release chloride ions into the wastewater, causing corrosion. A green chlorine-free coagulant of polyaluminum ferric silicate (PSAF) was prepared by the copolymerization method to treat oily refractory wastewaters. Results showed that the highest removal efficiency of turbidity and chemical oxygen demand (COD) achieved 97.4% and 93.0% at a dosage of 700 mg/L, respectively. After PSAF coagulation, the chloride ion concentration was also almost the same as that in the raw wastewater. Thus, the chlorine-free coagulant is highly efficient and does not introduce additional chloride ions into the wastewater, avoiding corrosion.

Keywords: coagulation, chloride-free coagulant, oily refractory wastewater, coagulation performance

Procedia PDF Downloads 218

Authors: Di Wang, Li Fang, Shengyu Fang, Jianhua Li, Honghong Dong, Zhongzhi Zhang

Abstract:

Heavy oily refinery wastewater with the characteristics of high concentration of toxic organic pollutant, poor biodegradability and complicated dissolved recalcitrant compounds is intractable to be degraded. In order to reduce the concentrations of COD and total nitrogen pollutants which are the major pollutants in heavy oily refinery wastewater, the Anoxic - Oxic microbiological technology relies mainly on anaerobic microbial reactor which works with methanogenic archaea mainly that can convert organic pollutants to methane gas, and supplemented by aerobic treatment. The results of continuous operation for 2 months with a hydraulic retention time (HRT) of 60h showed that, the COD concentration from influent water of anaerobic reactor and effluent water from aerobic reactor were 547.8mg/L and 93.85mg/L, respectively. The total removal rate of COD was up to 84.9%. Compared with the 46.71mg/L of total nitrogen pollutants in influent water of anaerobic reactor, the concentration of effluent water of aerobic reactor decreased to 14.11mg/L. In addition, the average removal rate of total nitrogen pollutants reached as high as 69.8%. Based on the data displayed, Anoxic - Oxic microbial technology shows a great potential to dispose heavy oil sewage in energy saving and high-efficiency of biodegradation.

Keywords: anoxic - oxic microbiological technology, COD, heavy oily refinery wastewater, total nitrogen pollutant

Procedia PDF Downloads 493