scholarly journals Theoretical study and case analysis for a pre-dried pyrolysis coupled lignite-fired power system

2018 ◽  
Author(s):  
Ming Liu ◽  
Rongtang Liu ◽  
Junjie Yan
Keyword(s):  
Low Temperature ◽  
Case Analysis ◽  
Theoretical Models ◽  
Energy System ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Low Rank ◽  
Drying Process ◽  
Heat Value ◽  
Low Temperature Pyrolysis

Lignite, a kind of low rank coal, has the characteristics of high moisture, high volatile, high ash and low heat value. The low-temperature pyrolysis technology is potential to improve the utilization efficiency of lignite. Therefore, a lignite-based energy system integrated with pre-drying and low-temperature pyrolysis was proposed in this paper. To assess the influence of pre-drying process, theoretical models were developed based on thermodynamics, and a case analysis was then performed to get the quantitative effect of pre-drying on efficiency of energy utilization. Results show that pre-drying on PPPS theoretical model can significantly improve the utilization of lignite by 1.46%.Keywords: Lignite; Pre-drying; Low-temperature pyrolysis; Energy efficiency; Case analysis.   

Regional integrated energy system schemes selection based on risk expectation and Mahalanobis-Taguchi system

2021 ◽  
pp. 1-18
Author(s):  
Jiahang Yuan ◽  
Yun Li ◽  
Xinggang Luo ◽  
Lingfei Li ◽  
Zhongliang Zhang ◽  
...  
Keyword(s):  
Energy Demand ◽  
Choquet Integral ◽  
Subjective Evaluation ◽  
Risk Attitude ◽  
Energy System ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Energy Structure ◽  
Fuzzy Measures ◽  
Integrated Energy System

Regional integrated energy system (RIES) provides a platform for coupling utilization of multi-energy and makes various energy demand from client possible. The suitable RIES composition scheme will upgrade energy structure and improve integrated energy utilization efficiency. Based on a RIES construction project in Jiangsu province, this paper proposes a new multi criteria decision-making (MCDM) method for the selection of RIES schemes. Because that subjective evaluation on RIES schemes benefit under criteria has uncertainty and hesitancy, intuitionistic trapezoidal fuzzy number (ITFN) which has the better capability to model ill-known quantities is presented. In consideration of risk attitude and interdependency of criteria, a new decision model with risk coefficients, Mahalanobis-Taguchi system and Choquet integral is proposed. Firstly, the decision matrices given by experts are normalized, and then are transformed to minimum expectation matrices according to different risk coefficients. Secondly, the weights of criteria from different experts are calculated by Mahalanobis-Taguchi system. Mobius transformation coefficients based on interaction degree are to calculate 2-order additive fuzzy measures, and then the comprehensive weights of criteria are obtained by fuzzy measures and Choquet integral. Thirdly, based on group decision consensus requirement, the weights of experts are obtained by the maximum entropy and grey correlation. Fourthly, the minimum expectation matrices are aggregated by the intuitionistic trapezoidal fuzzy Bonferroni mean operator. Thus, the ranking result according to the comparison rules using the minimum expectation and the maximum expectation is obtained. Finally, an illustrative example is taken in the present study to make the proposed method comprehensible.

Evaluation of Energy Efficiency for a CCHP System With Available Microturbine

2007 ◽  
Author(s):  
H. X. Liang ◽  
Q. W. Wang
Keyword(s):  
Gas Turbine ◽  
Waste Heat ◽  
Energy System ◽  
Primary Energy ◽  
Economic Benefits ◽  
Optimal Operation ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Energetic Efficiency ◽  
Efficiency Evaluation

This paper deals with the problem of energy utilization efficiency evaluation of a microturbine system for Combined Cooling, Heating and Power production (CCHP). The CCHP system integrates power generation, cooling and heating, which is a type of total energy system on the basis of energy cascade utilization principle, and has a large potential of energy saving and economical efficiency. A typical CCHP system has several options to fulfill energy requirements of its application, the electrical energy can be produced by a gas turbine, the heat can be generated by the waste heat of a gas turbine, and the cooling load can be satisfied by an absorption chiller driven by the waste heat of a gas turbine. The energy problem of the CCHP system is so large and complex that the existing engineering cannot provide satisfactory solutions. The decisive values for energetic efficiency evaluation of such systems are the primary energy generation cost. In this paper, in order to reveal internal essence of CCHP, we have analyzed typical CCHP systems and compared them with individual systems. The optimal operation of this system is dependent upon load conditions to be satisfied. The results indicate that CCHP brings 38.7 percent decrease in energy consumption comparing with the individual systems. A CCHP system saves fuel resources and has the assurance of economic benefits. Moreover, two basic CCHP models are presented for determining the optimum energy combination for the CCHP system with 100kW microturbine, and the more practical performances of various units are introduced, then Primary Energy Ratio (PER) and exergy efficiency (α) of various types and sizes systems are analyzed. Through exergy comparison performed for two kinds of CCHP systems, we have identified the essential principle for high performance of the CCHP system, and consequently pointed out the promising features for further development.

scholarly journals Optimal Configuration of Integrated Energy System Based on Energy-Conversion Interface

2019 ◽  
Vol 9 (7) ◽  
pp. 1367 ◽  
Author(s):  
Zicong Yu ◽  
Xiaohua Yang ◽  
Lu Zhang ◽  
Yongqiang Zhu ◽  
Ruihua Xia ◽  
...  
Keyword(s):  
Energy Conversion ◽  
Energy System ◽  
Optimal Configuration ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Environmental Cost ◽  
Maintenance Cost ◽  
Configuration Model ◽  
Energy Prices ◽  
Integrated Energy System

Aiming at the optimal configuration of a regional integrated energy system (IES), this paper proposes an energy-conversion interface (ECI) model that simplifies the complex multienergy network into a multi-input–multioutput dual-port network, consequently achieving the energy-coupling relationship between the energy-supply side and the demand side. An optimized configuration model of the ECI was constructed by considering economic performance, such as device-installation cost, operation and maintenance cost, and environmental cost, as well as energy-saving performance, such as energy-utilization efficiency. Then, the ECI optimal-configuration model was established by taking a campus in northern China as an example. To verify the validity of the model, device planning quantity and daily energy scheduling of the integrated energy system of the campus were obtained by solving the model with the particle-swarm optimization method. Finally, sensitivity analysis of the system to energy prices and the reweight approach for the targets are also given in this paper, providing a decision-making basis for system planning.

Research Progress of Oil Making from Sewage Sludge

2016 ◽  
Vol 851 ◽  
pp. 232-236
Author(s):  
Jiang Long Lu ◽  
Guo Ri Dong ◽  
Fang Chen ◽  
Ji Bin Wang
Keyword(s):  
High Temperature ◽  
Sewage Sludge ◽  
Low Temperature ◽  
Hot Spots ◽  
Energy Utilization ◽  
Research Progress ◽  
Treatment And Disposal ◽  
Low Temperature Pyrolysis

the treatment and disposal of sewage sludge is one of the hot spots in recent years, and the value of its energy utilization has gradually received attention by researchers. In this paper, the concept, yield, harm as well as the conventional disposal methods of sewage sludge are described, three kinds of main technologies of oil making from sewage sludge are introduced, including high temperature pyrolysis, low-temperature pyrolysis and direct thermo chemical liquefaction, and the research progress of these three technologies is reviewed.

Low-Temperature Pyrolysis Characteristics of Inner Mongolia Lignite

2013 ◽  
Vol 805-806 ◽  
pp. 1455-1460
Author(s):  
Zhen Xin Zhao ◽  
Bu Wei Ma ◽  
Shu Quan Zhu ◽  
Hai Jin Zheng
Keyword(s):  
Low Temperature ◽  
Inner Mongolia ◽  
Heat Content ◽  
Calorific Value ◽  
Product Yield ◽  
High Heat ◽  
Holding Time ◽  
Low Rank ◽  
Pyrolysis Characteristics ◽  
Low Temperature Pyrolysis

The utilization of high moisture, high volatile low rank coals such as lignite is gaining importance day by day to meet the growing demands of coal for the energy sectors. For the combustion of pulverized material it appears essential to dry lignite. Further, lowest possible ash and moisture as well as high heat content are desired for combustion. The present work gives the details of the preparation of a product of higher calorific value by thermal treatment of Inner Mongolia lignite. The low-temperature pyrolysis characteristics were carried out on the regularities of pyrolysis temperature and holding time on the product yield of dry distillation of lignite by using aluminium retort method. The result shows that the suitable pyrolysis condition of lignite is 450 ~ 510 °C, holding time for 30 min. The ratio of aliphatic and aromatic groups of 400°C semi-coke obviously decrease 53.1% and 11.8% compared with raw coal. The degree of aromatization of semi-coke is gradually increased and aromatic nucleus condensation degree increases. The retort process of lignite is a dehydrogenation, deoxidization and carbon-rich process.

scholarly journals An Energy Efficiency Index Formation and Analysis of Integrated Energy System Based on Exergy Efficiency

2021 ◽  
Vol 9 ◽  
Author(s):  
Huiling Su ◽  
Qifeng Huang ◽  
Zhongdong Wang
Keyword(s):  
Energy Efficiency ◽  
Evaluation Model ◽  
Second Law Of Thermodynamics ◽  
Energy System ◽  
Efficiency Index ◽  
Exergy Efficiency ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Efficiency Evaluation ◽  
Integrated Energy System

In the context of the energy crisis and environmental deterioration, the integrated energy system (IES) based on multi-energy complementarity and cascaded utilization of energy is considered as an effective way to solve these problems. Due to the different energy forms and the various characteristics in the IES, the coupling relationships among various energy forms are complicated which enlarges the difficulty of energy efficiency evaluation of the IES. In order to flexibly analyze the energy efficiency of the IES, an operation efficiency evaluation model for the IES is established. First, energy utilization efficiency (EUE) and exergy efficiency (EXE) are proposed based on the first/second law of thermodynamics. Second, the energy efficiency models for five processes and four subsystems of the IES are formed. Lastly, an actual commercial-industrial park with integrated energy is employed to validate the proposed method.

scholarly journals Energy Conversion and Transmission Characteristics Analysis of Ice Storage Air Conditioning System Driven by Distributed Photovoltaic Energy System

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Yongfeng Xu ◽  
Ming Li ◽  
Reda Hassanien Emam Hassanien
Keyword(s):  
Air Conditioning ◽  
Structure Optimization ◽  
Energy Coupling ◽  
Energy System ◽  
Exergy Efficiency ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Ice Storage ◽  
Air Conditioning System ◽  
Photovoltaic Energy

In order to reduce the investment and operation cost of distributed PV energy system, ice storage technology was introduced to substitute batteries for solar energy storage. Firstly, the ice storage air conditioning system (ISACS) driven by distributed photovoltaic energy system (DPES) was proposed and the feasibility studies have been investigated in this paper. And then, the theoretical model has been established and experimental work has been done to analyze the energy coupling and transferring characteristics in light-electricity-cold conversion process. In addition, the structure optimization analysis was investigated. Results revealed that energy losses were high in ice making process of ice slide maker with only 17.38% energy utilization efficiency and the energy efficiency and exergy efficiency of ISACS driven by DPES were 5.44% and 67.30%, respectively. So the immersed evaporator and cointegrated exchanger were adopted for higher energy utilization efficiency and better financial rewards in structure optimization. The COP and exergy efficiency of ice maker can be increased to 1.48 and 81.24%, respectively, after optimization and the energy utilization efficiency of ISACS driven by DPES could be improved 2.88 times. Moreover, ISACS has the out-of-the-box function of ordinary air conditioning system. In conclusion, ISACS driven by DPES will have good application prospects in tropical regions without power grid.

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