scholarly journals Study of Methods and Development of Technological Scheme for Heat Removal from Rock Waste Dump

2017 ◽  
Vol 25 ◽  
pp. 128-135 ◽  
Author(s):  
Pavlo Saik
Keyword(s):  
Heat Recovery ◽  
Coal Gasification ◽  
Waste Heat ◽  
Renewable Energy Sources ◽  
Heat Removal ◽  
Heat Pumps ◽  
Technological Scheme ◽  
Underground Coal Gasification ◽  
Waste Dump ◽  
Waste Dumps

The aim of this paper is to study the methods and develop technological scheme for thermal energy removal from coal mine rock waste dumps. The prospects of renewable energy sources development in Ukraine are analyzed. A number of available ways for using the sources of waste heat of mining enterprises, namely: outlet ventilation flow, mine water and other rock waste dumps, are investigated. The technological scheme of heat recovery from rock waste dump using heat pumps, which are component segments of the heat pump geosystem on the basis of borehole underground coal gasification, is developed.

scholarly journals Enabling thermal efficiency improvement and waste heat recovery using liquid air harnessed from offshore renewable energy sources

2020 ◽  
Vol 275 ◽  
pp. 115351 ◽  
Author(s):  
Julian D. Osorio ◽  
Mayank Panwar ◽  
Alejandro Rivera-Alvarez ◽  
Chrys Chryssostomidis ◽  
Rob Hovsapian ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Thermal Efficiency ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Renewable Energy Sources ◽  
Energy Sources ◽  
Efficiency Improvement

Multi-criterion comparison of compression and absorption heat pumps for ultra-low grade waste heat recovery

Energy ◽  
2022 ◽  
Vol 238 ◽  
pp. 121804
Author(s):  
Z.Y. Xu ◽  
J.T. Gao ◽  
Bin Hu ◽  
R.Z. Wang
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Heat Pumps ◽  
Low Grade

Evaluation of Applying Low Calorific Fuel as Reburn Fuel in an Opposed Wall Fired Boiler

2009 ◽  
Vol 1 (3) ◽  
Author(s):  
Guang Xu ◽  
Wei Zhou ◽  
Larry W. Swanson ◽  
David K. Moyeda ◽  
Quang Nguyen
Keyword(s):  
Natural Gas ◽  
Thermal Performance ◽  
Power Plants ◽  
Alternative Fuels ◽  
Coal Gasification ◽  
Renewable Energy Sources ◽  
Heat Transfer Analysis ◽  
Injection System ◽  
Chemical Compositions ◽  
Underground Coal Gasification

The alternative fuels, such as biomass, municipal wastes, and underground coal gasification gas, become attractive to the power plants as renewable energy sources or economical fuels. However, the alternative fuels usually have much lower heating value and different chemical compositions from those of coal and natural gas. Firing these alternative fuels in the boilers that are originally designed for coal firing or natural gas firing may cause unexpected boiler operating issues and/or thermal performance degradation. A careful evaluation study is often required prior to implementation. This paper presents the results of a study that evaluated the feasibility of using an underground coal gasification gas as a reburn fuel. The evaluation was done on Eskom’s Majuba Unit 5, a 710 MWe opposed wall-fired boiler, located in South Africa. The study utilized heat transfer analysis and computational fluid dynamics models to (1) evaluate the impacts of firing low calorific fuel on boiler efficiency and the boiler auxiliary system performance, (2) develop a conceptual gas reburn injection system, and (3) evaluate the impacts of gas reburn on the boiler thermal performance and boiler NOx emissions. The results indicate that the underground coal gasification gas can be an effective reburn fuel for the Majuba boiler with upgrades on the auxiliary systems.

Low grade waste heat recovery using heat pumps and power cycles

Energy ◽  
2015 ◽  
Vol 89 ◽  
pp. 864-873 ◽  
Author(s):  
D.M. van de Bor ◽  
C.A. Infante Ferreira ◽  
Anton A. Kiss
Keyword(s):  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Heat Pumps ◽  
Low Grade ◽  
Power Cycles

scholarly journals Analysis of Different Strategies for Lowering the Operation Temperature in Existing District Heating Networks

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 321 ◽  
Author(s):  
Francesco Neirotti ◽  
Michel Noussan ◽  
Stefano Riverso ◽  
Giorgio Manganini
Keyword(s):  
Energy Efficiency ◽  
Power Plants ◽  
Waste Heat ◽  
Control Strategies ◽  
Renewable Energy Sources ◽  
District Heating ◽  
Heating System ◽  
Heat Pumps ◽  
Critical Parameters ◽  
District Heating System

District heating systems have an important role in increasing the efficiency of the heating and cooling sector, especially when coupled to combined heat and power plants. However, in the transition towards decarbonization, current systems show some challenges for the integration of Renewable Energy Sources and Waste Heat. In particular, a crucial aspect is represented by the operating temperatures of the network. This paper analyzes two different approaches for the decrease of operation temperatures of existing networks, which are often supplying old buildings with a low degree of insulation. A simulation model was applied to some case studies to evaluate how a low-temperature operation of an existing district heating system performs compared to the standard operation, by considering two different approaches: (1) a different control strategy involving nighttime operation to avoid the morning peak demand; and (2) the partial insulation of the buildings to decrease operation temperatures without the need of modifying the heating system of the users. Different temperatures were considered to evaluate a threshold based on the characteristics of the buildings supplied by the network. The results highlight an interesting potential for optimization of existing systems by tuning the control strategies and performing some energy efficiency operation. The network temperature can be decreased with a continuous operation of the system, or with energy efficiency intervention in buildings, and distributed heat pumps used as integration could provide significant advantages. Each solution has its own limitations and critical parameters, which are discussed in detail.

scholarly journals District Power-To-Heat/Cool Complemented by Sewage Heat Recovery

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 364 ◽  
Author(s):  
Marcello Aprile ◽  
Rossano Scoccia ◽  
Alice Dénarié ◽  
Pál Kiss ◽  
Marcell Dombrovszky ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Heat Recovery ◽  
Renewable Energy Sources ◽  
District Heating ◽  
Heat Pumps ◽  
Economic Feasibility ◽  
Operational Experience ◽  
Operational Parameters ◽  
Heating And Cooling

District heating and cooling (DHC), when combined with waste or renewable energy sources, is an environmentally sound alternative to individual heating and cooling systems in buildings. In this work, the theoretical energy and economic performances of a DHC network complemented by compression heat pump and sewage heat exchanger are assessed through dynamic, year-round energy simulations. The proposed system comprises also a water storage and a PV plant. The study stems from the operational experience on a DHC network in Budapest, in which a new sewage heat recovery system is in place and provided the experimental base for assessing main operational parameters of the sewage heat exchanger, like effectiveness, parasitic energy consumption and impact of cleaning. The energy and economic potential is explored for a commercial district in Italy. It is found that the overall seasonal COP and EER are 3.10 and 3.64, while the seasonal COP and EER of the heat pump alone achieve 3.74 and 4.03, respectively. The economic feasibility is investigated by means of the levelized cost of heating and cooling (LCOHC). With an overall LCOHC between 79.1 and 89.9 €/MWh, the proposed system can be an attractive solution with respect to individual heat pumps.

scholarly journals Design analysis methods for Stirling engines

2008 ◽  
Vol 19 (3) ◽  
pp. 4-19 ◽  
Author(s):  
H. Snyman ◽  
T.M. Harms ◽  
J.M. Strauss
Keyword(s):  
Renewable Energy ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Renewable Energy Sources ◽  
Design Analysis ◽  
Energy Sources ◽  
Simple Analysis ◽  
Methods Of Analysis ◽  
Stirling Engines

Worldwide attempts are being made to increase the use of our renewable energy sources as well as to use our current fossil fuel energy sources more effi-ciently. Waste heat recovery forms a substantial part of the latter and is the focus of this project. Stirling technology finds application in both the renewable energy sector and in waste heat recovery. Investigating the applicability of Stirling engines in the above-mentioned fields is relevant to develop more efficient external combustion units as well as to utilize our renewable energy sources. Developing a design analysis and synthesis tool capable of opti-mizing Stirling powered units forms the main objec-tive of this project. The methodology followed to achieve this, involved the application of three differ-ent methods of analysis, namely the method of Schmidt, the adiabatic analysis and the simple analysis based on a five volume approach. The Schmidt analysis is used to obtain the internal engine pressure which is a required input for the adiabatic analysis while the simple analysis intro-duces pumping losses and regenerator inefficien-cies. These methodologies are discussed briefly in this paper. Experimental verification of the analyti-cal data was carried out on a Heinrici Stirling engine and both the analytical data and the experi-mental data are presented here. Shortcomings of these methods of analysis are highlighted and an alternative approach to solve particular shortcom-ings is presented.

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