CHP System Research Articles

Three-stage Coordinated Dispatching of Wind Power-Photovoltaic-CSP-Thermal Power Combined Generation System

Aiming at the problem that the grid connection of intermittent renewable energy such as wind power and photovoltaics brings great uncertainty to the power system, a three-stage coordinated scheduling strategy of wind power-photovoltaic-concentrated solar energy is proposed. CSP Combined heat and power system. In the first stage, based on the day-ahead forecast data of wind power, photovoltaics and load, a “peak shaving” model of the combination of wind power-photovoltaic-CSP was established. In the second stage, according to the value of the remaining load after optimization in the first stage, a day-ahead economic dispatch model for thermal power units is established. In the third stage, based on the start-stop status and output of thermal power units in the first and second stages, the output of CSP plants and the intraday forecast data of wind power, photovoltaics, and loads, the establishment of an intraday thermal power joint regulation model and the establishment unit and CSP stations are established, and intraday scheduling plans are arranged. Case analysis shows that the proposed CHP system scheduling strategy can be supplemented by thermal power and CSP during load peak and trough periods, thereby minimizing the uncertainty brought by grid integration of wind power and photovoltaics. Introduce.

Analysis of coupling characteristics between solar energy and compressor extraction energy storage gas turbine CHP system

The regulation of compressor extraction and energy storage can improve the performance of gas turbine energy system. In order to make the gas turbine system match the external load more flexibly and efficiently, a gas turbine cogeneration system with solar energy coupling compressor outlet extraction and energy storage is proposed. By establishing the variable condition mathematical model of air turbine, waste heat boiler and solar collector, we use Thermoflex software to establish the variable condition model of gas turbine compressor outlet extraction, and analyze the variable condition of the coupling system to study the changes of thermal parameters of the system in the energy storage, energy release and operation cycle. Taking the hourly load of a hotel in South China as an example, this paper analyzes the case of the cogeneration system of solar energy coupling compressor outlet extraction and energy storage, and compares it with the benchmark cogeneration system. The results show that taking a typical day as a cycle, the primary energy utilization rate of the system designed in this paper is 3.2% higher than that of the traditional cogeneration system, and the efficiency is 2.4% higher.

Benefit analysis of 15 MW biomass direct-fired power cogeneration project

Biomass direct-fired power generation technology has many advantages in realizing large-scale harmless utilization of biomass resources. It is an effective way to achieve the goal of carbon peak and carbon neutrality. Taking the 15MW direct-fired biomass power generation project of typical unit configuration as an example, this paper constructs a CHP system with biomass as fuel to replace the traditional coal-fired boiler for power generation, analyzes its economic, environmental and energy-saving benefits. As shown by results, compared with the conventional coal-fired power plant, the system cannot only save more than 700000 tons of coal, but also reduce more than 1610.41 tons of carbon dioxide emission, more than 26.41 tons of sulfur dioxide emission and more than 3000 tons of smoke and dust every year. The adoption of a new boiler and straw thermal power technology can competently deal with the three major problems of energy use, environmental protection and farmer’s income increment, which is of great significance to realize the effective cycle of “resource product renewable resource” economy.

Optimal sizing of an integrated CHP and desalination system as a polygeneration plant for supplying rural demands

Simultaneous production of electricity, heat, and water is a global challenge for rural residential areas. In the present study, techno-economic optimization of a system including PV, wind turbine, generator, battery, and CHP system alongside brackish water reverse osmosis desalination system is investigated. The proposed polygeneration hybrid system provides the required loads of a village and health clinic in a rural area with a warm climate. This study aims to find the optimum energy cost of essential rural needs, including required electricity, heat, and water demands to improve remote areas' life quality. While previous studies often considered only one or two of these needs. Several sensitivity analyses based on the different economic and climate conditions are carried out. The grid breakeven distance, environmental aspects, and the developed hybrid energy system's technical performance are analyzed. The results demonstrate that the optimum system, including PV/WT/DG/CHP/Bat and reverse osmosis desalination unit has COE and NPC equal to 0.236 $/kWh and 428,246 $, respectively. Also, the CHP unit decreased the annual fuel consumption by about 224 m3/yr. Furthermore, the proposed hybrid system has a 58.4% lower CO2 emission than conventional natural gas-fired plants and less than 27 km of grid breakeven distance.

Efficiency Analysis of the Generation of Energy in a Biogas CHP System and its Management in a Waste Landfill – Case Study

Efficiency Analysis of the Generation of Energy in a Biogas CHP System and its Management in a Waste Landfill – Case Study

Feasibility of Hybrid Desalination Plants Coupled with Small Gas Turbine CHP Systems

Nowadays, several technologies for desalination processes are available and widely employed. However, they consume a considerable amount of energy and involve high capital and operating costs. Therefore, the techno-economic analysis of a system coupling different energy sources with the desalination processes is of value. The possibility of coupling a small gas turbine combined heat and power system (GT CHP) with hybrid desalination plants (HDPs) has been assessed in this study. The proposed gas turbine power generation system, based on a single-stage centrifugal compressor and an uncooled centripetal turbine, provides design simplicity and reasonable installation costs for the power generating plant. The hybrid desalination technique, based on the use of two different desalination technologies, i.e., Reverse Osmosis (RO) and a thermal desalination process, has been chosen to better exploit the electrical and thermal energy produced by the mini CHP plant. The proposed solution is numerically investigated from both thermodynamic and economic points of view, and the results of the thermodynamic analysis of the cycle are used as input for the evaluation of the amount of freshwater produced and of costs. The economic assessment of standalone desalination systems is also shown for the comparison with the hybrid solutions here proposed. Results show that the total cost of the water produced by MED + RO was less than the total cost of the water obtained by MSF + RO, and that the energy cost of MED + RO hybrid desalination system was about 15% less than that for stand-alone RO desalination technology. Thus, the MED + RO hybrid desalination system can be considered a promising solution for the coupling with the proposed mini GT CHP plant, which, due to the small size and cost, as well as the easy installation, can be easily applied in off-grid or remote areas.

Techno-Economic Power Dispatching of Combined Heat and Power Plant Considering Prohibited Operating Zones and Valve Point Loading

Co-generation units (i.e., combined heat and power plants—CHPs) are playing an important role in fulfilling the heat and power demand in the energy system. Due to the depletion of fossil fuels and rising carbon footprints in the environment, it is necessary to develop some alternatives as well as energy efficient operating strategies. By utilising the waste heat from thermal plants, cogeneration units help to decrease energy generation costs as well as reduce emitted pollutants. The combined heat and power economic dispatch (CHPED) operation strategy is becoming an important optimisation task in the energy efficient operation of a power system. The optimisation of CHPED is quite complex due to the dual dependence of heat and power in the cogeneration units. The valve point loading effect and prohibited operating zones of a thermal power unit make the objective function non-linear and non-convex. In this work, to address these issues more effectively, the viable operational area of the CHP and power system network losses are considered for the optimal allocation of power output and heat generation. A metaheuristic optimisation algorithm is proposed to solve the CHPED to minimize the fuel supply, thus satisfying the constraints. To handle equality and inequality constraints, an external penalty factor-based constraint handling technique is used. The success of the proposed CHPED algorithm is tested on three considered cases. In all the cases, the results show the effectiveness in terms of solution accuracy and better convergence.

Possibilities of Using Sustainable Energy Technologies including CHP Systems, Solar Photovoltaics and Heat Pumps in Hospitals

Hospitals consume large amounts of energy in their daily operations. The necessity to comply with the global targets for climate change mitigation requires the decrease in their energy and fossil fuels consumption as well as reduction of their CO2 emissions. The aims of the current work are to study the possibilities of using several clean and low carbon emission technologies for heat, cooling and electricity generation in hospitals. The use of solar-PV panels, CHP systems and heat pumps has been examined as well as the possibility of financing these environmentally friendly energy technologies with external funding. Our results indicate that the abovementioned sustainable energy technologies are mature, reliable and cost-efficient providing heat, cooling and electricity in hospitals having also positive economic, social and environmental impacts. Their combined use with other low or zero carbon emission technologies could help in the transformation of hospital buildings to nearly zero energy buildings minimizing or zeroing their carbon footprint due to energy use. Various financial tools have been developed so far utilizing mainly private funds for financing clean energy investments in hospitals with external resources. Present work is important since it indicates that the previously mentioned sustainable energy technologies can be used in hospitals assisting in their transformation to low carbon emission organizations since in coming decades the mitigation of climate change in our societies will be necessary and crucial.

Multi-Fidelity Combustor Design and Experimental Test for a Micro Gas Turbine System

A multi-fidelity micro combustor design approach is developed for a small-scale combined heat and power CHP system. The approach is characterised by the coupling of the developed preliminary design model using the combined method of 3D high-fidelity modelling and experimental testing. The integrated multi-physics schemes and their underlying interactions are initially provided. During the preliminary design phase, the rapid design exploration is achieved by the coupled reduced-order models, where the details of the combustion chamber layout, flow distributions, and burner geometry are defined as well as basic combustor performance. The high-fidelity modelling approach is then followed to provide insights into detailed flow and emission physics, which explores the effect of design parameters and optimises the design. The combustor is then fabricated and assembled in the MGT test bench. The experimental test is performed and indicates that the designed combustor is successfully implemented in the MGT system. The multi-physics models are then verified and validated against the test data. The details of refinement on lower-order models are given based on the insights acquired by high-fidelity methods. The shortage of conventional fossil fuels and the continued demand for energy supplies have led to the development of a micro-turbine system running renewable fuels. Numerical analysis is then carried out to assess the potential operation of biogas in terms of emission and performance. It produces less NOx emission but presents a flame stabilisation design challenge at lower methane content. The details of the strategy to address the flame stabilisation are also provided.

Optimal and stochastic performance of an energy hub-based microgrid consisting of a solar-powered compressed-air energy storage system and cooling storage system by modified grasshopper optimization algorithm

Simultaneous operation of different energy generation and transmission infrastructures is a subject that has been considered under the concept of energy hub. This subject is highly regarded in the field of microgrids. One of the basic issues for investors is to properly utilize the energy hub for optimally managing energy carriers, especially in the energy price prediction. In the present paper, a new strategy is introduced for the energy hub in order to achieve the optimal performance of a microgrid (MG) that includes different energy carriers for each day. The objective of this strategy is to minimize the operation cost and consider the environmental issues. The proposed energy hub consists of a combined cooling-heating-power (CCHP) system along with a wind turbine and photovoltaic cells. The studied energy hub system is composed of an ice storage conditioner (ISC) system and an energy storage system (ESS) as the energy storage resource (ESR). One of the goals of the present work is to investigate the effect of solar-powered compressed-air energy storage (SPCAES) on the performance of the energy hub. The proposed strategy takes into account the uncertainty of the energy resources such as the wind and sun for meeting the electric, thermal, and cooling needs in different scenarios. In the present paper, to produce various scenarios, the Latin hypercube sampling (LHS) method is used. Also, the k-means method is used to reduce the number of scenarios. The objective function is solved using the modified grasshopper optimization algorithm (MGOA). According to the modeling results, the ESS can exhibit successful performance in the energy management strategy. • Considering the effects of the SPCAES and ISC on optimal performance of the energy hub. • Considering the effects of the SPCAES and ISC on the optimal performance. • Application of generations sources as PV, WT, CHP system, and TESS.

Investigation and Optimization of the Performance of Energy Systems in the Textile Industry by Using CHP Systems

With the general progression of small communities toward greater industrialization, energy consumption in this sector has increased. The continued growth of energy consumption seen in Iran, along with the low efficiency of production, transmission, and the distribution of energy, has led to the projection of an unfavorable future for this sector. The purpose of this study is to reduce fuel consumption and increase system efficiency by considering the optimal position of the turbine. In this regard, turbine modeling has been performed by considering different positioning scenarios. Afterward, the result from applying each scenario was compared with another scenario in terms of the parameters of electrical energy production, gas consumption, the final energy produced by the system, and the ratio of energy produced to overall gas consumption. After comparing different scenarios, considering all 4 parameters, Scenario 7 was selected as the most suitable positioning for gas turbine placement. Scenario 7 showed the highest gas consumption; of course, high power generation is the most desirable, the most reliable and, ultimately, the most profitable outcome of energy production. According to our results, the amount of electrical energy produced in the selected scenario is 4,991,160.3 kWh; the gas consumption in this case is 0.22972 kg/s.

Optimal configuration planning of rule and optimization-based driven storage coupled micro cogeneration systems by the implementation of constraint programming

In this paper, an optimization model for optimal size and dispatch planning of micro combined heat and power systems regarding distinct structures for the inclusion of the cogeneration unit, auxiliary boiler, heat storage and battery storage in the configuration of the system is introduced. The presented model is developed in a unified form by the implementation of constraint programming to consider different strategies for the system's operation. Furthermore, important details such as minimum/maximum permissible state of charge, maximum charge/discharge rate and battery inverter for modeling practical storages as technical specifications and simultaneous consideration of calendar life and life cycle as service life as well as assessment of heat dumping avoidance has been taken into account in this study. The model has been applied to three operation strategies and four kinds of buildings while considering two single-objective and one multi-objective optimization for minimization of the greenhouse gas emissions and annual costs of the system. The study has been validated by multiple study cases and the analyzes indicate that the implementation of different structures for the configuration of the micro CHP systems can impressively affect the optimum size and dispatch of these systems in each operation strategy. Comparison of the obtained results for the candidate multi-criteria solutions considering the exploitation of different storage options indicates that the inclusion of the heat storage by up to 21.5% further reduction in annual expenditures with an equal amount of emissions is a more influential energy storage option for utilization in the proposed residential cogeneration system. Regarding heat dumping assumption, dumping avoidance can be a powerful key factor in the system's management to prevent extra greenhouse generations by restricting the heedless minimization of the annual costs when it adversely affects the generation of the emissions.

Peak Regulation Performance Study of GTCC Based CHP System with Compressor Inlet Air Heating Method

Peak Regulation Performance Study of GTCC Based CHP System with Compressor Inlet Air Heating Method

Comparison of Moroccan Argan Nut Shell and Olive Cake Combustion to Determine the Best Combustible for CHP System and for the Thermodynamic Cycle

Comparison of Moroccan Argan Nut Shell and Olive Cake Combustion to Determine the Best Combustible for CHP System and for the Thermodynamic Cycle

Modeling and Multi-Objective Optimization of Chp System with Approach Economic, Environmental and Energy in Microgrid

Modeling and Multi-Objective Optimization of Chp System with Approach Economic, Environmental and Energy in Microgrid

Comparative Designs and Optimizations of the Steam Ejector for the Chp Systems

Comparative Designs and Optimizations of the Steam Ejector for the Chp Systems

Various thermoeconomic assessments of a heat and power system with a micro gas turbine engine used for industry

The natural gas fired combined heat and power system driven by a micro gas turbine engine (M−CHP) of a dairy products company is investigated basing on the actual test data. The system is investigated along with economic analysis and specific cost (SPECO), exergy-cost-energy-mass (EXCEM), modified EXCEM (m-EXCEM) thermoeconomic analyses. The present worth of M−CHP system is estimated to be 241,190.20 US$. According to SPECO method, the cost formation of waste exergy in the M−CHP system is found as 6.634 US$/h, while the combustion chamber component of the system has the maximum (worst) waste exergy cost rate to be 4.366 GJ/h. According to EXCEM method, the waste exergy cost formation of M−CHP system is determined to be 0.563x10-6 GJ/hUS$, while it is estimated as 0.078 GJ/US$ with m-EXCEM method. Among the components of the system, the combustion chamber has the worst waste exergy cost rate.

Energy, exergy, exergoeconomic, and environmental analyses and multi-objective optimization of a biomass-to-energy integrated thermal power plant

A novel biomass-driven heat and power cogeneration system comprising biomass gasification, a gas turbine, a Stirling engine, and a supercritical carbon dioxide cycle integrated with a domestic water heater was proposed in this work. Different biomass feedstocks (paper, wood, paddy husk, and municipal solid waste) were used in the gasifier as the input fuel. The devised system was analyzed from energy, exergy, exergoeconomic, and environmental viewpoints. Moreover, the effect of integrating the Stirling engine with the stand-alone CHP system is studied. Moreover, a detailed parametric analysis was performed to assess the effect of varying operating parameters on system efficiency. Finally, multi-objective optimization using genetic algorithm in MATLAB software was performed to obtain the optimum operating points. According to the results, using municipal solid waste as the input biomass resulted in the highest exergy efficiency by 41.36% and the lowest CO2 emission by 0.9021t/MWh. Also, the system with the Stirling engine had a higher exergy efficiency and lower CO2 emission than the system without the Stirling engine. According to the optimization results, the maximum obtainable exergy efficiency was 42.03%, which was related to MSW. Also, the minimum achievable cp,tot was 10.94$/GJ, attributable to the respective paddy husk.

Comparison and optimization of different fuel processing options for biogas-fed solid-oxide fuel cell plants

The biogas needs to be reformed before electro-chemical conversion in the solid-oxide fuel cell, which can be promoted efficiently with wise thermal management and reforming conditions. To ensure the system safety and catalysts durability, additional mineral-bearing water and carbon deposition should be avoided. This paper conducted a detailed biogas-SOFC CHP system analysis considering four layouts, featuring hot and cold recirculation of the anode off-gas, partial oxidation and complete internal reforming. The process optimization and sensitivity analysis are performed with the design variables including the recirculation ratio, and external reformer temperature. The anode supported SOFC operates at 800 °C and 0.4 A/cm2 current density. The results show that pre-reforming with hot recirculation and cold recirculation schemes achieve the highest system efficiency between 56% and 63%. The pre-reforming with hot recirculation scheme has a broader self-sufficient water range eliminating the carbon deposition risk at the recirculation ratio of 42–78% and reforming temperature of 400–650 °C. The no pre-reforming with hot recirculation scheme achieves maximum system efficiency of 58% due to the fuel dilution. Moreover, the partial oxidation with hot recirculation scheme maximum efficiency is limited to 58.9%, given that the partial oxidation reaction is less efficient than steam and dry reforming reactions. The proposed system layout could demonstrate the feasibility of biogas-SOFC with different reforming options especially on small scale with high efficiency and optimal thermal integration opportunities.

Performance improvement of a heat recovery system combined with fuel cell and thermoelectric generator: 4E analysis

In the present work, the performance improvement of a waste heat recovery system is investigated by applying a fuel cell and thermoelectric generator. With the use of energy, exergy, exergo-economic, and environmental analyses (4E analysis), the performance of the improved system is evaluated. A mathematical simulation in the Engineering Equation Solver (EES) is developed for basic and modified systems. Comparative analysis is carried out to demonstrate the benefit of the suggested system. The logical and correct combination of appropriate subsystems can lead to the maximum exploitation of an energy source, which is the innovation of the present work. The comparison of suggested system (PR/FC-TEG) with the CHP system indicates that the net output power of the PR/FC-TEG system is 3881 kW compared with 958.4 kW for the CHP system. However adding fuel cell to the PR/FC-TEG system increase output power by about 2162 kW, and it imposes 4823 kW exergy destruction rate to the system. The exergy destruction rate of the PEM FC, regenerator, and vapor generator are about 88.96% of the total exergy destruction rate, which infers the importance of these components in the PR/FC-TEG system improvement. Parametric analysis on the PR/FC-TEG performance with changing four influencing parameters is performed. Results indicate that increasing the turbine 1 inlet temperature by about 1.1% increases the cost of generated electricity from 72.92 to 73.88 $/GJ and decreases the sustainability index from 1.68 to 1.65. The multi-objective optimization of the developed system can be a promising option for future study.