Four Methods of Hydrogen Combustion within Combined Heat and Power Plants to Increase Power Output

In recent years, there has been an increasingly larger fraction of intermittent energy sources. In the northern parts of Europe, the main source of intermittent power is wind power. This source of power is low inertia, inconsistent and will always fluctuate with different magnitudes, leaving a need for balancing. One source of balancing is to have the widespread non-zero inertia combined heat and power stations work as back-up sources. One way to boost the capability of these power sources is by adding an oxyfuel internal hydrogen combustor. To study the effects of this, the steam generator was tested in four different positions within the power plant to test different possibilities with different levels of retrofits. The first was in the high- and lowpressure crossover, the second was a reheat at a higher pressure, the third was a superheat of the admission steam and finally, the fourth was a superheat using the overload valves. The final results showed that the configurations of crossover reheat, and superheat of admission steam were the best in terms of retrofit while the reheat at higher pressure was deemed the best in terms of backup capacity, reaching a gain in power of 9.5 MW at a fuel efficiency of 30.93 %. The highest fuel efficiencies were shown by the latter two, amounting to 45.19 % and 51.58 % in district heating mode, respectively. There is great potential to be made from these power plants due to the possibility of increased capacity all across Sweden.