Fuel Cell Combined Heat and Power Systems

Korsgaard, A.R., Nielsen, M.P., and Kaer, S.K. (2008) Part two control of a novel HTPEM-based micro combined heat and power fuel cell system. Int.J. Hydrogen Energy, 33, 1921. 

Romero-Pascual E, Soler J (2013) Modelling of am HT-based micro-combined heat and power fuel cell system with methanol. Int J Hydrogen Eneigy 39 4053- 59... 

PBI membranes have been the critical components in high temperature polymeric electrolyte membrane fuel cells. PBI fuel cells tolerate much more impurities in the Hj fuel compared to low temperature fuel cells. Therefore, they are preferred in fuel cell systems where the Hj supplies are from reformers converting other fuels to Hj. PBI fuel cells are also suitable for combined heat and power fuel cell systems. In other applications, PBI membranes have been successfully demonstrated to purify Hj while pumping it against a high pressure. The technology can be applied... 

For a combined heat and power (CH P) system for a one-family house, an optimum configuration with respect to cost effectiveness was determined by Schmid and Wiinning [16]. The fuel cell system was shown to provide about 70% of the average annual heat demand of the house, while peaks in demand were buffered by a conventional burner with an efficiency of 95%. The relative energy savings P of the fuel processor/fuel cell system over a centralised power supply with conventional steam gas turbines (SGT) was calculated as follows ... 

Figure 1.16 Phosphoric acid fuel cell. In addition to providing 200kW of electricity, it also provides about 200 kW of heat energy in the form of steam. Such units are called combined heat and power or CHP systems. (Reproduced by kind permission of ONSI Corporation.)...

This fuel cell has shown promise for combined heat and power systems (CHP systems). In such systems, the waste heat is used to heat buildings or to do work. Efficiency in a CHP plant can reach 80%. These plants could replace heating plants and power sources in colleges and universities, hotels, and apartment buildings. 

The modular design of the HyPM fuel cells allows scaling for higher power requirements using a variety of configurations, such as series and parallel systems. Potential applications for the technology include vehicle propulsion, auxiliary power units (APU), stationary applications including backup and standby power units, combined heat and power units and portable power applications for the construction industry and the military. 

For the stationary generation of heat and power the PEMFC is also in development. Fuel cell systems for combined heat and power generation mostly run on natural gas, and sometimes on biogas. Reformate is fed to the anode in these stationary systems. Only for backup power systems, which are designed for only a limited operating time, is pure hydrogen often used as fuel for the anode. 

Many studies have shown that the potential market is enormous. For instance, a 2000 study for the doe s Energy Information Administration found that the technical market potential for combined heat and power (chp) at commercial and institutional facilities was 75,000 mw, of which more than 60 percent was in systems less than 1 mw in size. This sub-MW market is a very good match for fuel cell technologies. The remaining technical potential in the industrial sector is about 88,000 mw. That analysis did not look at the opportunity created by heat-driven chillers to expand the market for cogeneration, nor did it contemplate cost-effective systems in sizes below 100 kW, as are being pursued by a number of fuel-cell (and other) companies.37... 

Hawkes A, Leach M, (2005). Sohd oxide fuel cell systems for residential micro-combined heat and power in the UK Key economic drivers. Journal of Power Sources, 149 72-83 Hellmana H, van den Hoed R, (2007). Characterising fuel cell technology Challenges of the commercialisation process. International Journal of Hydrogen Energy 32 305 - 315 Hermann A, Chaudhuri T, Spagnol P, (2005). Bipolar plates for PEM fuel cells A review. 

Barclay F J, 2002, Fundamental thermodynamics of fuel cell, engine, and combined heat and power system efficiencies. Proceedings of the Institution of Mechanical Engineers, Part A, Journal of Power and Energy, 216, 407-417. 

The PEM fuel cell is the leading alternative for building-integrated applications, where multi-functionality would allow current natural gas burners to be replaced by combined heat-and-power systems, possibly with the additional option of supplying hydrogen to a one-vehicle filling station. One may think that if the automobile industry is successful in developing a viable... 

Fuel cells, especially PEMFCs, can be used for various applications ranging from portable power supply for use in consumer electronic devices to stationary deployment for combined heat and power generation. Another potential application is transportation, in which fuel cell systems are developed for the propulsion of cars. The performance, operating conditions, costs, and durability requirements differ depending on the application. Transportation applications demand stringent requirements on fuel cell systems. Only the durability requirement in the transportation field is not as rigorous as the stationary application, although cyclic durability is necessary. 

Fuel-cell technology allows the direct conversion of chemical energy into electricity [7]. The fuel cell is an electrochemical reactor where the catalyst systems are an important component. Among the wide-ranging applications of fuel cells are low-emission transport systems, stationary power stations, and combined heat and power sources. The classical studies were carried out in the early 1900s, and major innovations and improvements have been achieved over the last few years. The first new electric cars are expected to roll onto the market around the year 2005, but... 

A small fuel cell of about 1-kW in capacity, could cogenerate year-round to provide base-load power and hot water. Larger fuel cells would provide too much heat than a home can use most of the time. The DOE estimates that the optimal size for a residential combined heat and power (CHP) or cogeneration system in the United States is about 0.75-kW for a PEM fuel cell. 

The fuel cell is an electrochemical reactor, the required output of which is the energy released rather than the reaction product. The main fields of its application include transport systems, stationary power generation, and combined heat and power sources. What emerges from the specialist literature is that, despite the innovations and improvements made in recent years, there is still much room for further developments. " Central to the success of fuel-cell technology are the catalyst systems. This is where bi- and multi-metallic nanostructured colloids, especially those of small particle size (1-2.5 nm), scattering as nearly perfect single crystals , are important. They offer improved efficiency and tolerance against CO-... 

Fuel cells are being developed for stationary use at either the small residential or commercial level or at the larger commercial level to provide a power source as well as supply backup electricity. In addition, much of this development uses excess heat from electricity production in combined heat and power (CHP) fuel ceU systems. These stationary applications are being tested in real-world applications in hopes of marketing them in the near future. 

In the case of stationary systems, where 80 to 90 % of the heat is also extracted from the fuel cell system as valuable energy (and not considered waste) the total (electric and heat) efficiency of the combined heat and power generation can achieve >80%. 

In most cases, large fuel cell-based stationary power plants are used for power production and, at the same time, for heat supply to customers in nearby locations (combined heat and power (CHP) systems). This combined use of two different types of energy implies a very considerable increase in the total economic and energetic efficiencies of these plants. 

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