Hydrogen production technology for powering civil and industrial systems : a review
Partial use of alternative energy exemplified by hydrogen energy is expected to reduce negative impacts associated with the current dependence on fossil energy and bring net gain to regional and national economies. Hydrogen has emission levels that are far below the existing and possibly, future standards. Hydrogen energy may enhance energy security and perhaps allay concerns some concerns about global climatic change, environmental issues, energy efficiency, and infrastructure development. Since the production of hydrogen is energy-intensive, a production technique that negates this disadvantage with a high volume output within a reasonable time, is desirable.
Fuel cell alternative for locomotive propulsion
Abstract The electrification of railway systems as an alternative to diesel-electric locomotion is under serious consideration in Ontario and other parts of Canada. Proposals for electrification of parts of Canada's railways point out that we have abundant electricity, particularly from hydraulic and CANDU sources and suggest that wherever appropriate, we should move the transportation sector from oil to electricity. However, electricity is not the only energy currency that can be harvested from these non-fossil derived sources. The hydrogen fuel cell powered locomotive provides a means of indirect electrification and holds advantages over direct railroad electrification in several areas. This paper develops a conceptual design of an alkaline fuel cell powered locomotive system and compares its performance to diesel and electric alternatives on the basis of energy consumption and energy cost. The technical analysis of the propulsion system described in this paper is based on computer simulation software developed to model the performance of a bipolar alkaline fuel cell running on electrolytic-grade hydrogen. This is a generalized model which may be applied to any application duty cycle, given transient voltage and current duty cycles. Locomotive duty cycle requirements were defined for freight and passenger locomotives powered by both shunt and series traction motors along the Montreal to Toronto corridor. The most appropriate fuel cells for freight and passenger applications were selected subject to weight, volume, and current density constraints. The fuel cell performances were then compared with diesel and electric counterparts. This paper concludes that the fuel cell locomotive is a competitive alternative propulsion system for railway electrification and should be considered in any study exploring alternatives to diesel-fueled locomotives.
Assessment of Ground Regeneration around Borehole Heat Exchangers between Heating Seasons in Cold Climates: A Case Study in Bialystok (NE, Poland)
Based on the experimental studies, the process of ground regeneration around the borehole loaded with brine-water heat pumps working exclusively for heating purposes in the period of four consecutive heating seasons in a cold climate was presented. The research was conducted in north-eastern Poland. The aim of the work is to verify the phenomenon of thermal ground regeneration in the period between heating seasons on the basis of the recorded data and to check whether the ground is able to regenerate itself and at what rate. It was noticed that the ground does not fully regenerate, especially during heating seasons with lower temperatures. In the analyzed period, from 22 September 2016 to 12 October 2020, the ground probably cooled irreversibly by 1.5 °C. In order to illustrate and evaluate the speed of changes in the ground, the one’s profile with an undisturbed temperature field was presented for each month of the year. The presented results can be a very important source of information for the analysis of geothermal conditions occurring in the ground. They can be used to verify mathematical models and conduct long-term simulations that allow us to see the complexity of the processes taking place in the ground.