scholarly journals A Comparison of Different Approaches for Assessing Energy Outputs of Combined Heat and Power Geothermal Plants

2021 ◽  
Vol 13 (8) ◽  
pp. 4527
Author(s):  
Daniele Fiaschi ◽  
Giampaolo Manfrida ◽  
Barbara Mendecka ◽  
Lorenzo Tosti ◽  
Maria Laura Parisi
Keyword(s):  
Power Generation ◽  
Low Temperature ◽  
Power Plants ◽  
District Heating ◽  
Primary Energy ◽  
Combined Heat And Power ◽  
Geothermal Systems ◽  
Allocation Scheme ◽  
Component Level ◽  
Temperature Level

In this paper, we assess using two alternative allocation schemes, namely exergy and primary energy saving (PES) to compare products generated in different combined heat and power (CHP) geothermal systems. In particular, the adequacy and feasibility of the schemes recommended for allocation are demonstrated by their application to three relevant and significantly different case studies of geothermal CHPs, i.e., (1) Chiusdino in Italy, (2) Altheim in Austria, and (3) Hellisheidi in Iceland. The results showed that, given the generally low temperature level of the cogenerated heat (80–100 °C, usually exploited in district heating), the use of exergy allocation largely marginalizes the importance of the heat byproduct, thus, becoming almost equivalent to electricity for the Chiusdino and Hellisheidi power plants. Therefore, the PES scheme is found to be the more appropriate allocation scheme. Additionally, the exergy scheme is mandatory for allocating power plants’ environmental impacts at a component level in CHP systems. The main drawback of the PES scheme is its country dependency due to the different fuels used, but reasonable and representative values can be achieved based on average EU heat and power generation efficiencies.

Evaluation and Optimization of Automated Operation in Small CHP Plants

2000 ◽  
Author(s):  
Jeppe Grue ◽  
Jens Andersen ◽  
Niels From ◽  
Inger Bach
Keyword(s):  
Power Generation ◽  
Objective Function ◽  
Electric Power ◽  
Power Plants ◽  
Electrical Power ◽  
District Heating ◽  
Combined Heat And Power ◽  
Optimal Operating ◽  
Gas Engine ◽  
Operating Strategy

Abstract In Denmark power generation is extensively based on small combined heat and power plants, which produce electric power and district heating. This work will focus on the small plants around 1 MW in size, which are often unmanned and operating completely automatically. The objective of this work is to formulate a method which can be used to determine the optimal operating strategy for a CHP plant, and that this strategy must be fully automated. The contribution margin of the plant is used as the objective function for the optimization. Finally the method is tested on a small CHP plant, which is a gas engine producing 1.34 MW electrical power and 1.6 MJ/s district heating. The methods, which are developed, can be used in general for the evaluation and optimization of automated strategies for the operation of small-unmanned CHP plants. The strong feature of the method is that it sets an ultimate target that is the best possible one to obtain with a view to any strategy. This provides a basis for the evaluation and optimization of the actual strategy.

System effects of lowered district heating supply temperatures

2020 ◽  
pp. 14-24
Author(s):  
Tina Lidberg ◽  
Thomas Olofsson ◽  
Louise Ödlund
Keyword(s):  
Power Plants ◽  
Energy Use ◽  
Cost Optimization ◽  
District Heating ◽  
Energy System ◽  
Primary Energy ◽  
Combined Heat And Power ◽  
Electricity Production ◽  
Fuel Use ◽  
Significant Difference

Lowering temperature levels of a district heating (DH) system may offer several advantages such as reduced distribution losses, increased efficiency of flue gas condensation equipment and increased electricity generation in combined heat and power plants. In a broader perspective this can result in more efficient use of natural resources as well as reduced climate-impacting emissions. This study examines how decreased DH supply temperatures influence the power-to-heat ratio and thereby electricity production and fuel use in a combined heat and power plant. Carbon dioxide equivalent (CO2-eqv.) emissions and primary energy use were calculated with three different marginal electricity perspectives. A regional DH system situated in mid-Sweden was used as a case study and the energy system cost optimization modelling tool MODEST (Model for Optimization of Dynamic Energy Systems with Time-Dependent Components and Boundary Conditions) was used. The results show that decreasing the DH supply temperature results in increased electricity production as well as increased fuel use within the system. Further, there is a significant difference in CO2-eqv. emissions and primary energy use for the studied marginal electricity perspectives.

scholarly journals Using adsorption chillers for utilising waste heat from power plants

2019 ◽  
Vol 23 (Suppl. 4) ◽  
pp. 1143-1151 ◽  
Author(s):  
Karol Sztekler ◽  
Wojciech Kalawa ◽  
Sebastian Stefanski ◽  
Jaroslaw Krzywanski ◽  
Karolina Grabowska ◽  
...  
Keyword(s):  
Power Generation ◽  
Energy Efficiency ◽  
Power Plant ◽  
Power Plants ◽  
Waste Heat ◽  
Primary Energy ◽  
Simulation Software ◽  
Coefficient Of Performance ◽  
Low Grade ◽  
Adsorption Chiller

At present, energy efficiency is a very important issue and it is power generation facilities, among others, that have to confront this challenge. The simultaneous production of electricity, heat and cooling, the so-called trigeneration, allows for substantial savings in the chemical energy of fuels. More efficient use of the primary energy contained in fuels translates into tangible earnings for power plants while reductions in the amounts of fuel burned, and of non-renewable resources in particular, certainly have a favorable impact on the natural environment. The main aim of the paper was to investigate the contribution of the use of adsorption chillers to improve the energy efficiency of a conventional power plant through the utilization of combined heat and power waste heat, involving the use of adsorption chillers. An adsorption chiller is an item of industrial equipment that is driven by low grade heat and intended to produce chilled water and desalinated water. Nowadays, adsorption chillers exhibit a low coefficient of performance. This type of plant is designed to increase the efficiency of the primary energy use. This objective as well as the conservation of non-renewable energy resources is becoming an increasingly important aspect of the operation of power generation facilities. As part of their project, the authors have modelled the cycle of a conventional heat power plant integrated with an adsorption chiller-based plant. Multi-variant simulation calculations were performed using IPSEpro simulation software.

300 MW Combined-Cycle Plant With Integrated Coal Gasification

1984 ◽  
Author(s):  
Rolf H. Kehlhofer
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Gas Turbines ◽  
Power Plants ◽  
Coal Gasification ◽  
District Heating ◽  
Combined Cycle ◽  
Liquid Fuels ◽  
Combined Cycle Plant ◽  
The Individual

In the past 15 years the combined-cycle (gas/steam turbine) power plant has come into its own in the power generation market. Today, approximately 30 000 MW of power are already installed or being built as combined-cycle units. Combined-cycle plants are therefore a proven technology, showing not only impressive thermal efficiency ratings of up to 50 percent in theory, but also proving them in practice and everyday operation (1) (2). Combined-cycle installations can be used for many purposes. They range from power plants for power generation only, to cogeneration plants for district heating or combined cycles with maximum additional firing (3). The main obstacle to further expansion of the combined cycle principle is its lack of fuel flexibility. To this day, gas turbines are still limited to gaseous or liquid fuels. This paper shows a viable way to add a cheap solid fuel, coal, to the list. The plant system in question is a 2 × 150 MW combined-cycle plant of BBC Brown Boveri with integrated coal gasification plant of British Gas/Lurgi. The main point of interest is that all the individual components of the power plant described in this paper have proven their worth commercially. It is therefore not a pilot plant but a viable commercial proposition.

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