A Novel Coal-Fired CHP System Integrated With Steam Ejectors to Realize Heat-Power Decoupling and Energy Saving

Abstract Traditional combined heat and power (CHP) units should run in the heat-controlled mode. The adjustable range of power load is restricted by the heat load, and the minimum power load increases with the heat load. Because of high penetration of intermittent renewable power, operational flexibility of CHP units is highly required. It is necessary to adopt some technical solutions to realize heat-power decoupling for CHP units. To find a heat-power decoupling method with low investment and high energy efficiency, the steam ejectors, simple in structure and low in cost, are applied to design a novel heat-power decoupling system in this study. Steam ejectors can recover the waste heat of exhaust steam of steam turbines. Therefore, the integration of steam ejector may realize heat-power decoupling and energy saving simultaneously. Three heat-power decoupling systems with steam ejectors are designed. The heat-power decoupling performance and energy consumption characteristics of these systems are investigated with a reference 330 MW coal-fired CHP unit. Results show that all three modified systems can realize heat-power decoupling. The heat-power decoupling performance of improved system III is the best, and improved system I has the least coal consumption rate for power generation.

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Heat and Power Decoupling and Energy Saving of the CHP Unit with Heat Pump Based Waste Heat Recovery System

SSRN Electronic Journal ◽

10.2139/ssrn.3944464 ◽

2021 ◽

Author(s):

Haichao Wang ◽

Pengmin Hua ◽

Xiaozhou Wu ◽

Ruoyu Zhang ◽

Katja Granlund ◽

...

Keyword(s):

Energy Saving ◽

Heat Pump ◽

Heat Recovery ◽

Waste Heat Recovery ◽

Waste Heat ◽

Waste Heat Recovery System ◽

Recovery System ◽

Heat Recovery System ◽

Power Decoupling

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Research on Heat/Power Load Optimizing Distribution Model of Heating Units Based on Gene Sequencing Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1008-1009.562 ◽

2014 ◽

Vol 1008-1009 ◽

pp. 562-566

Author(s):

Wen Sheng Zhao ◽

Xiao Dong Ding ◽

Zhi Wang

Keyword(s):

Consumption Rate ◽

Thermal Power ◽

Gene Sequencing ◽

Distribution Model ◽

Heat Power ◽

Coal Consumption ◽

Operating Condition ◽

Sequencing Method ◽

Power Load ◽

Saving Effect

Based on the basic idea of biological gene sequencing method,“Shotgun Method”,this paper proposes a new method of heat/power load optimizing distribution,named as “Shotgun Method”.This method is mainly based on historical operating data of thermal power plant,and puts the reciprocal of fuel utilization coefficient in the physical sense—factory comprehensive standard coal consumption rate as thermal economic index.Through the calculation of thermal system of principle,every unit can get its own coal consumption characteristic equation,as the foundation operating condition library for the heat/power load distribution.“Shotgun Method” aims at minimum factory comprehensive standard coal consumption rate to establish mathematical model for seeking the best match between operating condition library of each unit.The application instance shows that this method is simple,practical,and the energy saving effect is remarkable.

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Analysis of Cement Kiln Waste Heat Power Generation System Using the Exergy Analysis Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.860-863.639 ◽

2013 ◽

Vol 860-863 ◽

pp. 639-644

Author(s):

Jian Gang Wang ◽

Pu Yan Zheng ◽

Zhi Yun Zhou ◽

Yan Zhou Yuan

Keyword(s):

Power Generation ◽

Energy Saving ◽

Energy Use ◽

Waste Heat ◽

Scientific Basis ◽

Economic Benefits ◽

Cement Kiln ◽

Heat Power ◽

Generation System ◽

Power Generation System

Power generation using waste heat from cement kiln can not only bring economic benefits to the enterprise, but also play an important role in environment protection. Constantly researches have proved that there is still large energy saving potential in its operation. In this paper, the waste heat power generation system was divided into several subsystems, and the exergy calculation model of each subsystem unit was established. Finally, the weakest part in energy use was found according to the results. It provides a scientific basis for performance improvement and energy saving transformation of waste heat power generation.

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Steam-Water Modelling and the Coal-Saving Scheduling Strategy of Combined Heat and Power Systems

Energies ◽

10.3390/en15010141 ◽

2021 ◽

Vol 15 (1) ◽

pp. 141

Author(s):

Junshan Guo ◽

Wei Zheng ◽

Zhuang Cong ◽

Panfeng Shang ◽

Congyu Wang ◽

...

Keyword(s):

Heat Load ◽

Large Scale ◽

Combined Heat And Power ◽

Energy Utilization ◽

Utilization Efficiency ◽

Adaptive Mutation ◽

Small Scale ◽

Coal Consumption ◽

Scheduling Strategy ◽

Power Load

China aims to peak carbon emissions by 2030. As a result, small-scale coal-fired combined heat and power (CHP) units and self-provided units are gradually shut down, and large-scale coal-fired CHP units are a solution to undertake the industrial heat loads. From the perspective of the industrial heat load allocation during the non-heating season, the problems regarding the coal-saving scheduling strategy of coal-fired CHP units are addressed. The steam-water equations of CHP units are established to analyze the heat-power coupling characteristics. The energy utilization efficiency, exergy efficiency and the coal consumption are analyzed. The optimization model of saving coal consumption is established and the adaptive mutation particle swarm optimization (AMPSO) is introduced to solve the above model. The 330 MW coal-fired CHP unit is taken as an example, and the results show that for the constant main flow rate, each increase of 1 t/h industrial steam extraction will reduce the power output by about 0.321 MW. The energy utilization efficiency and the exergy are mainly influenced by industrial steam supply and the power load, respectively. For the CHP system with two parallel CHP units, the unequal allocation of industrial heat load between two units saves more coal than equal allocation. The coal consumption can be reduced when the unit with lower power load undertakes more industrial heat load. In the typical day, the total coal consumption after optimization is 3203.92 tons, a decrease of 14.66 tons compared to the optimization before. The two CHP units in the case can benefit about 5,612,700 CHY extra in one year.

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A Novel Coal-Fired CHP System Integrated With Steam Ejectors to Realize Heat-Power Decoupling and Energy Saving

10.1115/1.0000411v ◽

2021 ◽

Author(s):

Miaomiao Liu ◽

MING LIU ◽

Shuran Zhao ◽

Gege Song ◽

Junjie Yan

Keyword(s):

Energy Saving ◽

Heat Power ◽

Power Decoupling ◽

Chp System

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Research on Technical Route Optimization and Energy-saving Characteristics of High-temperature Subcritical Retrofit

E3S Web of Conferences ◽

10.1051/e3sconf/202126104012 ◽

2021 ◽

Vol 261 ◽

pp. 04012

Author(s):

He An Wu ◽

Feng Wei Zhong ◽

Y. Li

Keyword(s):

High Temperature ◽

Energy Saving ◽

Consumption Rate ◽

Comprehensive Analysis ◽

Route Optimization ◽

Steam Turbines ◽

Coal Consumption ◽

Actual System ◽

Reheat Steam ◽

Main Steam

In order to further reduce the power supply coal consumption rate for 300MW subcritical units, this paper will conduct a comprehensive analysis to improve the main steam and reheat steam parameters of those units based on the basic principles of thermodynamics, steam turbines and water pumps. The analysis shows that for the subcritical unit retrofit method that only raises the main steam and reheat steam temperature as the basic technical route has better feasibility. On this basis, combined with the actual system and working conditions of the 320MW subcritical unit, a simulation model of the entire plant’s thermal system is established for calculation and analysis. The calculation results show that the heat consumption rate of the high-temperature subcritical retrofit can reach 7526.7kJ/kWh. Combined with China Resources Xuzhou #3 unit high temperature subcritical comprehensive retrofit project (using high temperature subcritical transformation and equipped with special energy saving transformation), A comprehensive analysis of the performance of the unit after retrofit. The analysis shows that the coal consumption rate after the retrofit is reduced by 36g/kWh.

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Thermodynamic Analysis on a Heat-Power Decoupling System Integrated With Absorption Heat Pump

ASME 2020 Power Conference ◽

10.1115/power2020-16309 ◽

2020 ◽

Author(s):

Liyuan Wang ◽

Ming Liu ◽

Yue Fu ◽

Jiping Liu ◽

Junjie Yan

Keyword(s):

Power Generation ◽

Heat Pump ◽

Consumption Rate ◽

Heat Power ◽

Coal Consumption ◽

Absorption Heat Pump ◽

Primary Network ◽

Power Decoupling ◽

Heating Load ◽

Rate Of Heating

Abstract Because of the continuous expanding of the district heating, the heating load of combined heat and power (CHP) plants increases year by year. The minimum power load of CHP plant increases with the heating load due to the heat-power coupling mechanism. Therefore, heat-power decoupling is necessary to improve the operation flexibility for CHP units. Integrating the absorption heat pump (AHP) is an effective method to realize the heat-power decoupling. In this study, a 330MW CHP unit model and AHP model have been developed and validated. The performance of the heat-power decoupling and energy saving performance has been investigated by comparing the thermodynamic performance indicators. Results show that, the proposed system can increase the maximum heating load and decrease the power generation when the primary network return temperature is decreased. When the heating steam extraction is kept constant, with the increase of the primary network return water temperature, the heat generation efficiency and the standard coal consumption rate of heating increases, the coal consumption rate of power generation and the heating efficiency decreases. And the primary network return water temperature increases from 40 °C to 70 °C, the coal consumption rate of power generation decreases by 4.3 g/kWh, and the coal consumption rate of heating increases by 0.67 kg/GJ.

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