Energy efficiency evaluation model based on DEA-SBM-Malmquist index

A long-distance natural gas pipeline system consists of considerable equipment and many pipe segments, but the conventional energy efficiency index of a natural gas pipeline is considered as a whole. Because the specific energy consumption of each unit cannot be determined, the index system is not perfect, and evaluating the energy efficiency of a natural gas pipeline system is difficult. The energy efficiency evaluation model for a natural gas pipeline was established using the analytic hierarchy process. A judgment matrix was constructed based on the energy efficiency index system of a long-distance natural gas pipeline, and the weight coefficient was calculated using the characteristic root method. Then, the consistency of the established judgment matrix was verified. The energy efficiency evaluation model successfully quantified the qualitative factors that affect natural gas pipelines. The comprehensive energy efficiency coefficient G of the natural gas pipeline was obtained from the operational data of the natural gas pipeline; then, the equipment or pipe segments with high energy consumption can be identified. The energy efficiency evaluation program of the natural gas pipeline was developed using Visual Basic for Applications, which significantly reduced the evaluation workload. The natural gas pipeline energy efficiency evaluation model is used to evaluate the energy efficiency of a natural gas pipeline, to identify the high energy consumption equipment or pipe segments, and to propose measures to improve the energy efficiency. The results show that the gas pipeline energy efficiency evaluation model and evaluation procedures can identify high energy consumption equipment or pipe sections in complex natural gas pipelines.

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Study of the Comprehensive Evaluation of Energy Efficiency of an Oilfield Heating Furnace Based on Combination Weighting Method

Journal of Thermal Science and Engineering Applications ◽

10.1115/1.4047169 ◽

2020 ◽

Vol 13 (1) ◽

Author(s):

Qinglin Cheng ◽

Ronghuan Wang ◽

Wei Sun ◽

Lan Meng ◽

Wei Gao ◽

...

Keyword(s):

Energy Efficiency ◽

Energy Consumption ◽

Evaluation Model ◽

Heating Furnace ◽

Efficiency Evaluation ◽

Gas Temperature ◽

Load Rate ◽

Excess Air Coefficient ◽

Energy Efficiency Evaluation ◽

Exhaust Gas Temperature

Abstract The heating furnace is an essential oilfield facility for surface gathering, treatment, and transportation, so the energy consumption level of an oilfield is directly affected by its operational efficiency. In this paper, the thermal efficiency, exhaust gas temperature, external surface temperature, excess air coefficient, and load rate of a heating furnace are taken as energy efficiency evaluation indexes. By improving game theory, the objective and subjective weights are combined to determine the final weights of each index. On this basis, the grey TOPSIS method is used to establish the energy efficiency evaluation model of an oilfield heating furnace, which is to comprehensively evaluate the energy consumption of the heating furnace by calculating the closeness degree between its actual and ideal operational states. Finally, the effectiveness of the energy efficiency evaluation model is verified by taking an actual oilfield as an example, the results show that the weight sequence of the indexes is thermal efficiency, exhaust gas temperature, external surface temperature, load rate, and excess air coefficient. In addition, the relative closeness of the heating furnace is mostly concentrated between 0.5 and 0.7, which shows that the efficiency is low. The weak link of energy consumption is analyzed, and the corresponding improvement measures are put forward.

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