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 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 The analysis and research on variable operating condition of exhaust steam and waste heat Cascade utilization system of air cooling heating unit

2019 ◽  
Vol 136 ◽  
pp. 01002
Author(s):  
Ning Zhao ◽  
Xiaoying Fan ◽  
Lite Ji ◽  
Ya-mi Chen
Keyword(s):  
Heat Pump ◽  
Waste Heat ◽  
Optimal Operation ◽  
Operating Conditions ◽  
Energy Utilization ◽  
Utilization Efficiency ◽  
Air Cooling ◽  
Analysis Model ◽  
Exhaust Heat ◽  
Heat Pump Unit

The series and parallel exhaust heat cascade utilization system was adopted by the large direct air cooling heating units. On the one hand, this system could reduce the adverse impact on power generation; on the other hand, it could reduce the temperature difference of heat transfer through step by step heating, the irreversible loss could be reduced, and the energy utilization efficiency could be made higher. On the basis of grasping the design performance of exhaust steam utilization system and the variable operating performance of main equipment by analysing the data of typical operating conditions, the optimization analysis model of heat pump group and the whole plant was established by this paper. The performance of heat pump unit under variable operating conditions was analysed and calculated, the influence of different exhaust pressure and backwater temperature on the economy of the whole machine was analysed, and the optimal operation mode of the heat pump was obtained. Finally, the pumping and condensing ratio curves under different conditions of winter heating conditions were determined, which could guide the optimal operation of heat pump units. It also provided technical support and basis for deep peak regulation or flexible transformation of heating units.

scholarly journals Calculation and Analysis of the Interval Power Flow for Distributed Energy System Based on Affine Algorithm

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 600
Author(s):  
Bin Ouyang ◽  
Lu Qu ◽  
Qiyang Liu ◽  
Baoye Tian ◽  
Zhichang Yuan ◽  
...  
Keyword(s):  
Power Flow ◽  
Load Condition ◽  
Energy Systems ◽  
Energy System ◽  
Optimal Operation ◽  
Energy Utilization ◽  
Utilization Rate ◽  
Distributed Energy ◽  
Low Load ◽  
Distributed Energy System

Due to the coupling of different energy systems, optimization of different energy complementarities, and the realization of the highest overall energy utilization rate and environmental friendliness of the energy system, distributed energy system has become an important way to build a clean and low-carbon energy system. However, the complex topological structure of the system and too many coupling devices bring more uncertain factors to the system which the calculation of the interval power flow of distributed energy system becomes the key problem to be solved urgently. Affine power flow calculation is considered as an important solution to solve uncertain steady power flow problems. In this paper, the distributed energy system coupled with cold, heat, and electricity is taken as the research object, the influence of different uncertain factors such as photovoltaic and wind power output is comprehensively considered, and affine algorithm is adopted to calculate the system power flow of the distributed energy system under high and low load conditions. The results show that the system has larger operating space, more stable bus voltage and more flexible pipeline flow under low load condition than under high load condition. The calculation results of the interval power flow of distributed energy systems can provide theoretical basis and data support for the stability analysis and optimal operation of distributed energy systems.

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.

scholarly journals Research on Multi-dimensional Energy Efficiency Assessment Technology of RIES

2020 ◽  
Vol 218 ◽  
pp. 01046
Author(s):  
Kuihua Wu ◽  
Zhijie Zheng ◽  
Lujie Qi ◽  
Rong Liang ◽  
Bo Yang
Keyword(s):  
Energy Efficiency ◽  
Evaluation System ◽  
Energy System ◽  
Assessment Method ◽  
Economic Benefits ◽  
Evaluation Index System ◽  
Efficiency Evaluation ◽  
Efficiency Assessment ◽  
Integrated Energy System ◽  
Energy Efficiency Evaluation

At present, there is a lack of regional comprehensive energy multi-dimensional evaluation system and calculation of different quality energy in the energy efficiency evaluation of regional integrated energy system. Based on this, this article carries out research on multi-dimensional energy efficiency evaluation index system and evaluation methods. First, this article form quantifiable evaluation indicators from the aspects of energy supply subsystem energy efficiency, energy conversion subsystem energy efficiency, grid energy efficiency, economic benefits and social benefits, and clarify the calculation methods of each evaluation indicator. Then this article calculate the indicator combination weight. Finally, a multi-dimensional energy efficiency assessment method for a regional integrated energy system is proposed, and an example is used to prove the effectiveness of the method.

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.   

Design and Operation of a Hybrid CCHP System Including PV-Wind Devices

2013 ◽  
Author(s):  
J. L. Wang ◽  
J. Y. Wu ◽  
C. Y. Zheng
Keyword(s):  
Fuel Consumption ◽  
Internal Combustion Engines ◽  
High Efficiency ◽  
Waste Heat ◽  
Internal Combustion ◽  
Energy System ◽  
Optimal Operation ◽  
Combustion Engines ◽  
Wind System ◽  
Fuel Price

CCHP systems based on internal combustion engines have been widely accepted as efficient distributed energy resources systems. CCHP systems can be efficient mainly because that the waste heat of engines can be recovered and used. If the waste heat is not used, CCHP systems may not be beneficial choices. PV-wind systems can generate electricity without fuel consumption, but the electric output depends on the weather, which is not reliable. A PV-wind system can be integrated into a CCHP system to form a higher efficient energy system. Actually, a hybrid energy system based on PV-wind devices and internal combustion engines has been studied by many researchers. But the waste heat of the engine is seldom considered in the previous work. Researches show that, 20∼30% energy can be converted into electricity by a small size engine while more than 70% is released. If the waste heat is not recovered, the system cannot reach a high efficiency. This work aims to analyze a hybrid CCHP system with PV-wind devices. Internal combustion engines are the prime movers whose waste heat is recovered for house heating or driving absorption chillers. PV-wind devices are added to reduce the fuel consumption and total cost. The optimal design method and optimal operation strategy are proposed basing on hourly analyses. Influences of the device cost and fuel price on the optimal dispatch strategies are discussed. Results show that all of the excess energy from the PV-wind system is not worth being stored by the battery. The hybrid CCHP system can be more economical and higher efficient in the studied case.

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.

A Recuperated Gas Turbine Incorporating External Heat Sources in the Combined Gas-Steam Cycle

2000 ◽  
Author(s):  
Ryszard Chodkiewicz ◽  
Jan Krysinski ◽  
Jerzy Porochnicki
Keyword(s):  
Gas Turbine ◽  
High Efficiency ◽  
Waste Heat ◽  
New Technology ◽  
Industrial Process ◽  
Energy System ◽  
Heat Sources ◽  
Exhaust Gases ◽  
Useful Heat ◽  
Steam Cycle

The recuperation by means of external waste heat sources, as opposed to the recuperation of the turbine exhaust gases (to preheat the compressed air), allows one to utilize the hot exhaust gases of the gas turbine in the bottoming steam cycle to produce steam in order to generate additional power. Such a combined gas/steam energy system, closely integrated with the industrial process, can produce electric power (and useful heat) with high efficiency and very low atmospheric air pollution. In the present paper two examples of applications of this new technology have been analyzed from the economic and ecological viewpoint.

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