Combined Heat And Power Plant Plant Research Articles

Evaluation of the effectiveness of technological measures to manage the risk to public health when exposed to atmospheric emissions of multi-fuel combined heat and power plants

AIM: To assess the effectiveness of technological measures to manage the risk to public health of exposure to atmospheric emissions from multi-fuel combined heat and power plants (CHP).
 METHODS: The study involved modeling the dispersion of emissions from the thermal power plants, calculation of surface concentrations, assessment of carcinogenic and non-carcinogenic risks to public health, and estimating the relative risk of mortality, referrals and hospitalizations based on WHO guidelines on atmospheric air quality. Predictive scenarios were constructed for thermal power plants, including the initial state, modernization with the help of technological and sanitary measures, and changes in the structure of the fuel balance.
 RESULTS: The use of low-temperature vortex fuel combustion technology in combination with a modernized dust and gas cleaning system significantly (p 0.001) decreased the predicted carcinogenic risk index by an average of 80.67%, non-carcinogenic risk index by 78.84%, and relative mortality risks and referrals to medical organizations by more than 80%. The use of a gas turbine plant increased the production of electric energy by 72.23%, thermal energy by 4.89%, and significantly (p 0.001) reduced the level of carcinogenic risk by 4460%, non-carcinogenic risk by 3547%, and relative risks of mortality, visits to medical organizations and hospitalizations by 3364%.
 CONCLUSION: The use of the best available technologies to modernize multi-fuel CHP plants significantly reduces the level of risk to public health while it increases the production of electric and thermal energy and maintaining the advantage of using both solid and gaseous fuels.

SPECIFICITY OF TRANSACTION COSTS AT BIOENERGY PRODUCERS – A CASE STUDY

One of the nexus in the modern energy sector are bioenergy companies. To generate green electricity, economic operators trade in the market, incurring transaction costs. The main objective of the paper is to identify and describe the transaction costs using a case study of biomass combined heat and power plant (CHP). The company used for the case study was Polmos Żyrardów. A diagnostic survey with a questionnaire was carried out. It was found that information procurement and negotiation costs are the most significant in the transaction cost structure of a biomass CHP plant. The importance of access to information about biomass suppliers in the region and the company›s closest surroundings was highlighted the most. This factor significantly increases the time-consuming activities that make up the process of acquiring information about a potential business partner. The aspect of the formalisation of the contract and the building of mutual trust between the participants in the transaction were emphasised as elements to minimise the uncertainty and opportunism of the partners. It is argued that the level of transaction costs influences decision-making within the organisation, also translating into the efficiency of the entire biomass CHP area. Conscious management of energy resources and care for the environment has made Polmos Żyrardów self-sufficient in energy. In light of the challenges of the energy transition, bioenergy installations make an important contribution to reducing greenhouse gas emissions and building circular bioeconomy.

Analysis of Air Pollution around a CHP Plant: Real Measurements vs. Computer Simulations

This study examines the concentrations of air pollution in the vicinity of a combined heat and power plant (CHP) and a communication route, using computer modeling of pollutant dispersion and spatial analysis based on real measurements in the city of Łódź, Poland, Europe. The research takes into account the concentrations of particulate matter (PM10, PM2.5, PM1.0) and gaseous pollutants (SO2 and VOC) in winter and summer. The spatial distribution of pollutants is discussed, including the presence of areas with increased accumulations of pollutants. Because atmospheric air has no natural boundaries, when analyzing any location, not only local sources of pollution, but also background pollution, should be analyzed. A clear difference was observed between the concentrations of pollutants in the summer and winter seasons, with significantly higher concentrations in the winter (heating) period. The impacts of road transport, individual heating systems, and combined heat and power plants were also assessed. Computer calculations confirmed that road transport accounted for the largest share of both PM and SO2 emissions. The CHP plant was responsible for the smallest percentage of dust emissions and was the next largest producer of SO2 emissions. The share of the total emissions from the individual sources were compared with the results of detailed field tests. The numerical analysis of selected pollution sources in combination with the field analysis shows that the identified pollution sources included in the analysis represent only a part of the total observed pollutant concentrations (suggesting that other background sources account for the rest).

Energy and Exergy Analysis of Sensible Thermal Energy Storage—Hot Water Tank for a Large CHP Plant in Poland

The paper contains a simplified energy and exergy analysis of pumps and pipelines system integrated with Thermal Energy Storage (TES). The analysis was performed for a combined heat and power plant (CHP) supplying heat to the District Heating System (DHS). The energy and exergy efficiency for the Block Part of the Siekierki CHP Plant in Warsaw was estimated. CHP Plant Siekierki is the largest CHP plant in Poland and the second largest in Europe. The energy and exergy analysis was executed for the three different values of ambient temperature. It is according to operation of the plant in different seasons: winter season (the lowest ambient temperature Tex = −20 °C, i.e., design point conditions), the intermediate season (average ambient temperature Tex = 1 °C), and summer (average ambient temperature Tex = 15 °C). The presented results of the analysis make it possible to identify the places of the greatest exergy destruction in the pumps and pipelines system with TES, and thus give the opportunity to take necessary improvement actions. Detailed results of the energy-exergy analysis show that both the energy consumption and the rate of exergy destruction in relation to the operation of the pumps and pipelines system of the CHP plant with TES for the tank charging and discharging processes are low.

Optimal dispatch of combined heat and power plant in integrated energy system: A state of the art review and case study of Copenhagen

This paper presents and classifies a state of the art optimal dispatch review of combined heat and power plants (CHP) in integrated energy systems. Comparing the purposes of increasing renewable energy integration and profits of CHP operation, two groups of literatures, cost and market based optimal dispatch of CHP plants are studied. The flexibility in terms of reducing wind power curtailment and increasing revenue by providing ancillary service is discussed. A case study of optimal dispatch of a CHP plant under the heat market in Copenhagen, Denmark is proposed, where the flexibility is compared with different CHP unit types, operation modes and heat accumulators’ integration.

Petrographic composition of coals and products of coal combustion from the selected combined heat and power plants (CHP) and heating plants in Upper Silesia, Poland

Coal samples and by-products resulting from the combustion process collected from seven combined heat and power (CHP) plants and heating plants located in Upper Silesia, southern Poland, were subjected to petrographic analysis. The coal used as a fuel in these plants was collected from mines of the Upper Silesian Coal Basin; it occurs in a wide range of coalification and has variable quality parameters. The coal is dominated by macerals from the vitrinite group; however, a high content of macerals from the inertinite group has also been observed. Based on petrographic analysis of ash and slags, a highly variable mineral matter content, confirming variable combustion efficiency, has been found. In the case of samples collected from large CHP plants with pulverized and fluidized bed boilers, the mineral matter content is high. The share of mineral matter in combustion products clearly decreases in the case of smaller power plants and heating plants, especially those using grate boilers. The increased content of unburned coal can be explained by the fact that coals of higher rank are often used as fuels in the mentioned plants.The greatest diversity of char forms can be observed in the case of samples collected from small CHP plants. In the case of three samples of slag, collected from small heating plants using grate boilers, additional presence of coke, thermally altered, and unaltered coal has also been found.

Energy Recovery from Waste Incineration—The Importance of Technology Data and System Boundaries on CO2 Emissions

Previous studies on waste incineration as part of the energy system show that waste management and energy supply are highly dependent on each other, and that the preconditions for the energy system setup affects the avoided emissions and thereby even sometimes the total outcome of an environmental assessment. However, it has not been previously shown explicitly which key parameters are most crucial, how much each parameter affects results and conclusions and how different aspects depend on each other. The interconnection between waste incineration and the energy system is elaborated by testing parameters potentially crucial to the result: design of the incineration plant, avoided energy generation, degree of efficiency, electricity efficiency in combined heat and power plants (CHP), avoided fuel, emission level of the avoided electricity generation and avoided waste management. CO2 emissions have been calculated for incineration of 1 kWh mixed combustible waste. The results indicate that one of the most important factors is the electricity efficiency in CHP plants in combination with the emission level of the avoided electricity generation. A novel aspect of this study is the plant by plant comparison showing how different electricity efficiencies associated with different types of fuels and plants influence results. Since waste incineration typically have lower power to fuel ratios, this has implications for further analyses of waste incineration compared to other waste management practises and heat and power production technologies. New incineration capacity should substitute mixed landfill disposal and recovered energy should replace energy from inefficient high polluting plants. Electricity generation must not be lost, as it has to be compensated for by electricity production affecting the overall results.

Industrial CHP excess heat efficient usage for cooling

This study investigates the possibilities how to utilize the combined heat and power plant (CHP) excess heat in the industry during the hot periods of time when the heat demand is limited. In order to maximize the CHP electricity production the efficient heat load has to be increased. The goal of this article is to present the solution for the industrial CHP excess heat utilization for the local cooling. The study introduces the method and model of how to evaluate the industrial CHP plant potential and economical benefit for the production of local cooling from the excess heat.

Methodology for the large scale assessment of the technical power potential of forest biomass: Application to the province of New Brunswick, Canada

In this study, a methodology is presented for the large scale assessment of forest biomass available over a territory with multiple land ownerships and to determine the technical power potential of this biomass for the commercial cogeneration of heat and power in industrial-sized combined heat and power plants (CHP). The forest biomass assessment of merchantable stem-wood is based on Annual Allowable Cut (AAC) data, while the biomass assessments of the other tree components are estimated using biomass allometric equations and biomass expansion factors. An application of the methodology is made to the province of New Brunswick, Canada. Results show that the total annual potential harvest of forest biomass in the study area is 15.5 Mt green weight (GT) at harvest from which approximately 63% would come from merchantable wood, 27% from residual biomass and 10% from bark. In term of electric and thermal power potential, the findings indicate that if all the forest biomass harvested annually in the province was to be used as fuel input in dedicated CHP plants, a total of 1.2 GW of electricity and 3 GW of thermal heat could be produced. In regards to the provincial spatial distribution of forest biomass, results from a cumulative perspective show that 22% of all forest biomass would come from a 25 km radius of the CHP plant sites identified in this study, 73% within a 50 km radius and 100% within a 125 km radius.

Establishment of a Model for a Combined Heat and Power Plant with ThermosysPro Library

The Simulation and Information Technologies for Power Generation System Department (STEP) has developed a methodology, as part of the framework of an EDF R&D project, to model and optimize energy systems for the associated companies with the aim of highlighting the possibility of using modelling tools to optimize energy systems. Dymola software, a commercial implementation of Modelica, which was developed by Dassault Systemes has been employed. A library, called ThermosysPro and developed by EDF R&D, has in particular been used. The energy system presented in the paper is a Combined Heat and Power plant (CHP), managed by Fenice SpA, which has been designed to supply electric and thermal energy to a food factory near Parma (Italy). This kind of system can be regulated over a large power range and, as a consequence, the CHP plant can supply the total amount of thermal energy required by the user. From a comparison of the experimental data and the simulation results, it can be seen that the behaviour of the turbo gas and the steam turbine approximately follows the results of the performance test at full load over a wide temperature range. As far as the performance at partial load, the gas turbine Heat Rate and the heat recovery steam generator (HRSG) performance are concerned, the simulation results and the actual CHP plant behaviour again appear to be in good agreement.

Assessing the environmental performance and sustainability of bioenergy production in Sweden: A life cycle assessment perspective

Bioenergy is one of the most dynamic and rapidly changing sectors of the global energy economy. The use of food crops for conversion to biofuel has been criticized for several reasons, among which its competition with the global food chain. Instead, lignocellulosic substrates are claimed to provide a bioenergy alternative without competing with food demand. This is particularly true when dealing with residues or waste. In this paper, we explored the environmental performance and sustainability of a bioenergy production system that integrates wastewater treatment, willow farming, and a Combined Heat and Power plant (CHP) located in Enköping (Sweden). Several methodologies for environmental assessment are integrated in this study within a life cycle perspective to investigate material and energy requirements as well as emissions and related impacts of the whole bioenergy production chain. Results show that full integration of different subsystems of a productive network is a desirable option for bioenergy production, within a zero emission oriented production pattern. The investigated wood biomass powered CHP plant was able to co-generate heat and electricity with high production efficiency and much better environmental performance and sustainability than fossil fuel based power plants.

Energy-consumption analysis of a confi guration of an absorption vapor compression coupled to MED in a dual-purpose power plant

A dual-purpose power plant that produces heating-water-cooling-power cogeneration is presented. It comprises LiBr-H2O absorption vapour compression (ABVC), low-temperature multieffect distillation (LT-MED) and combined heat and power plant (CHP). The low grade extraction or discharged steam from the steam turbine is used for heating as well as motive steam to drive LT-MED combined ABVC that produces fresh water and cooling. Based on the second law of thermodynamics, it is used to analyze the energy consumption of the dual- purpose power plant that the energy with different grades can be evaluated by the equivalent raw energy consumption. The effect of turbine's steam parameter on the specific raw energy consumption of water production is explored and the comparison of energy consumption between the dualpurpose power plant and CHP plant for different heating load is done. The results indicate that it is favourable to increase the parameter of fresh steam and reduce the parameters of the exit steam for redu...

Experimental investigation of a 125 kW twin-fire fixed bed gasification pilot plant and comparison to the results of a 2 MW combined heat and power plant (CHP)

Fixed bed biomass gasification is a promising technology to produce heat and power from a renewable energy source. A twin-fire fixed bed gasifier based CHP plant was realized in the year 2003 in Wr. Neustadt, Austria. Wood chips are used as fuel, which are dried and sieved before being gasified to a low calorific gas of about 5.8 MJ/Nm3dry. Before the clean gas is fed into a gas engine a cyclone and a RME (rapemethylester)/H2O quench system followed by a wet electrostatic precipitator (ESP) is used for gas cleaning. The CHP plant has a fuel power of 2 MWth and an electric output of 550 kWel. As scale up and optimization tool a hot test rig with a capacity of 125 kWth was built. Basic parameters like the type of wood chips, power and air distribution were varied to investigate the effect on gas composition, tar content in the producer gas and carbon content in the ash. Additionally a temperature profile over the height of the 125 kW hot test rig was measured. Furthermore, the results from the hot test rig are discussed and compared with the results from the 2 MWth demonstration plant.

Optimal supply and demand investments in municipal energy systems

In many municipalities, there are district heating networks, which are quite commonly supplied by combined heat and power plants (CHP). A district heating network contains buildings of different types. In this paper, one such municipal energy system is analysed. In order to provide space heating and domestic hot water, investments could be made on the supply side in power plants, or on the demand side in the buildings, for example in the form of extra wall insulation. The electricity from the CHP plants is supplied to the municipality but can also be sold to the electricity market, and electricity can, of course, also be bought from the market. The variation in price on the spot market over any given day is significant. The need for district heat in the building stock also varies, for example due to climatic conditions. The energy system in the case study is analysed with a mixed integer linear programming model. The model has 3 h time steps in order to reflect diurnal variations, and an entire year is analysed. A case study is presented for the city of Linköping in Sweden. On the demand side, the options are: extra wall insulation, extra attic insulation and better types of windows. The building stock is divided into nine categories.

Domestic-scale combined heat-and-power system incorporating a heat pump: analysis of a prototype plant

This paper introduces an innovative domestic scale combined heat-and-power plant (CHP), incorporating a heat pump (HP) for single-dwelling applications. The incorporation of a heat pump enhances the flexibility of a domestic scale CHP plant to satisfy domestic energy demand economically. The development, testing and subsequent thermodynamic analysis of the prototype plant are presented. First law thermodynamic analysis of experimental results is compared to equivalent second law analysis. Analysis of experimental results practically demonstrates that heat-pump incorporation satisfies extremely low domestic electrical requirements economically, whilst delivering relatively high thermal output, without resorting to electricity export.