scholarly journals Power to Hydrogen Through Polygeneration Systems Based on Solid Oxide Cell Systems

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4793 ◽  
Author(s):  
Marvin M. Rokni
Keyword(s):  
Hydrogen Production ◽  
Solar Energy ◽  
Wind Turbines ◽  
Production Efficiency ◽  
Waste Heat ◽  
District Heating ◽  
Solid Oxide ◽  
Plant Performance ◽  
Total Plant ◽  
Plant Efficiency

This study presents the design and analysis of a novel plant based on reversible solid oxide cells driven by wind turbines and integrated with district heating, absorption chillers and water distillation. The main goal is produce hydrogen from excess electricity generated by the wind turbines. The proposed design recovers the waste heat to generate cooling, freshwater and heating. The different plant designs proposed here make it possible to alter the production depending on the demand. Further, the study uses solar energy to generate steam and regulate the heat production for the district heating. The study shows that the plant is able to produce hydrogen at a rate of about 2200 kg/day and the hydrogen production efficiency of the plant reaches about 39%. The total plant efficiency (energy efficiency) will be close to 47% when heat, cool and freshwater are accounted for. Neglecting the heat input through solar energy to the system, then hydrogen production efficiency will be about 74% and the total plant efficiency will be about 100%. In addition, the study analyses the plant performance versus wind velocity in terms of heating, cooling and freshwater generation.

A System Analysis of Pressurized Electrolysis for Compressed Hydrogen Production

2019 ◽  
Author(s):  
Ryan T. Hamilton ◽  
Dustin McLarty
Keyword(s):  
Hydrogen Production ◽  
System Analysis ◽  
High Pressures ◽  
Waste Heat ◽  
Water Electrolysis ◽  
Plant Performance ◽  
Pressurized Water ◽  
Production Of Hydrogen ◽  
Hydrogen Compression ◽  
Plant Efficiency

Abstract Renewable production of hydrogen offers a clean and sustainable replacement of fossil fuels. As an energy carrier hydrogen is compressed and stored at high pressures. Pressurized water electrolysis improves plant performance as hydrogen compression is an energy intensive process. This work analyzes hydrogen production over the temperature range of 100°C to 800°C and pressure range of 1 bar to 700 bar. The sensitivity of plant efficiency to hydrogen compression technology and waste heat recovery is investigated. This study reveals that a lower-heating-value electric energy efficiency of 84% can be achieved when pressurized electrolysis avoids the inefficiencies of hydrogen compression. With the availability of high-quality waste heat plant efficiency can reach 98% for a pipeline distribution scenario at 3MPa. When no waste heat is available plant efficiency is independent of electrolysis temperature. For hydrogen use in the transportation sector, pressurized supercritical water electrolysis at 800°C has the potential to improve plant efficiency by 14% from a baseline of non-pressurized electrolysis at 800°C.

scholarly journals GE MS7001 Gas Turbine Advanced Technology Uprate

1996 ◽  
Author(s):  
Michael A. Cocca ◽  
Arthur Stappenbeck ◽  
James Van Wormer
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Advanced Technology ◽  
Plant Performance ◽  
Maintenance Costs ◽  
Performance Improvements ◽  
Efficiency Increase ◽  
Total Plant ◽  
Plant Efficiency

Today’s competitive world of Independent Power Producers and electric wheeling has increased demand for lower operating and maintenance costs and increased revenues. This need is driving gas turbine research and development. Application of advanced technology to operating units can increase output, improve total plant efficiency, increase steam production and reduce maintenance costs. Cogen Technologies is one owner that has applied advanced technology to uprate five Frame 7EA gas turbines at its Linden plant and one unit at its Camden facility. At the Linden plant, total plant efficiency was improved by more than 2%. This paper will discuss the components included in these advanced technology uprates, the gas turbine and combined-cycle plant performance improvements that were realized, and an economic model that can be used to evaluate the potential benefits of an uprate.

scholarly journals Local Heating Networks with Waste Heat Utilization: Low or Medium Temperature Supply?

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 954 ◽  
Author(s):  
Hanne Kauko ◽  
Daniel Rohde ◽  
Armin Hafner
Keyword(s):  
Low Temperature ◽  
Heat Pump ◽  
Urban Areas ◽  
Waste Heat ◽  
Local Heating ◽  
District Heating ◽  
Heat Pumps ◽  
Hot Water ◽  
Local Network ◽  
Medium Temperature

District heating enables an economical use of energy sources that would otherwise be wasted to cover the heating demands of buildings in urban areas. For efficient utilization of local waste heat and renewable heat sources, low distribution temperatures are of crucial importance. This study evaluates a local heating network being planned for a new building area in Trondheim, Norway, with waste heat available from a nearby ice skating rink. Two alternative supply temperature levels have been evaluated with dynamic simulations: low temperature (40 °C), with direct utilization of waste heat and decentralized domestic hot water (DHW) production using heat pumps; and medium temperature (70 °C), applying a centralized heat pump to lift the temperature of the waste heat. The local network will be connected to the primary district heating network to cover the remaining heat demand. The simulation results show that with a medium temperature supply, the peak power demand is up to three times higher than with a low temperature supply. This results from the fact that the centralized heat pump lifts the temperature for the entire network, including space and DHW heating demands. With a low temperature supply, heat pumps are applied only for DHW production, which enables a low and even electricity demand. On the other hand, with a low temperature supply, the district heating demand is high in the wintertime, in particular if the waste heat temperature is low. The choice of a suitable supply temperature level for a local heating network is hence strongly dependent on the temperature of the available waste heat, but also on the costs and emissions related to the production of district heating and electricity in the different seasons.

scholarly journals RELaTED Project: New Developments on Ultra-Low Temperature District Heating Networks

Proceedings ◽  
2020 ◽  
Vol 65 (1) ◽  
pp. 25
Author(s):  
Antonio Garrido Marijuan ◽  
Roberto Garay ◽  
Mikel Lumbreras ◽  
Víctor Sánchez ◽  
Olga Macias ◽  
...  
Keyword(s):  
Low Temperature ◽  
High Performance ◽  
Waste Heat ◽  
District Heating ◽  
Hot Water ◽  
Thermal Systems ◽  
Heating Source ◽  
Wide Range ◽  
Thermal Sources ◽  
Heating Networks

District heating networks deliver around 13% of the heating energy in the EU, being considered as a key element of the progressive decarbonization of Europe. The H2020 REnewable Low TEmperature District project (RELaTED) seeks to contribute to the energy decarbonization of these infrastructures through the development and demonstration of the following concepts: reduction in network temperature down to 50 °C, integration of renewable energies and waste heat sources with a novel substation concept, and improvement on building-integrated solar thermal systems. The coupling of renewable thermal sources with ultra-low temperature district heating (DH) allows for a bidirectional energy flow, using the DH as both thermal storage in periods of production surplus and a back-up heating source during consumption peaks. The ultra-low temperature enables the integration of a wide range of energy sources such as waste heat from industry. Furthermore, RELaTED also develops concepts concerning district heating-connected reversible heat pump systems that allow to reach adequate thermal levels for domestic hot water as well as the use of the network for district cooling with high performance. These developments will be demonstrated in four locations: Estonia, Serbia, Denmark, and Spain.

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