This paper studies the integration of heat pump units (HPUs) to enhance the thermal efficiency of a combined heat and power plant (CHPP). Different solutions of integrate the HPUs in a combined-cycle gas turbine (CCGT) plant, the CCGT-450, are analyzed based on simulations developed on “United Cycle” computer-aided design (CAD) system. The HPUs are used to explore low-potential heat sources (LPHSs) and heat make-up and return network water. The use of HPUs to regulate the gas turbine (GT) intake air temperature during the summer operation and the possibility of using a HPU to heat the GT intake air and replace anti-icing system (AIS), over the winter at high humidity conditions were also analyzed. The best solution was obtained for the winter operation mode replacing the AIS by a HPU. The simulation results indicated that this scheme can reduce the underproduction of electricity generation by the CCGT unit up to 14.87% and enhance the overall efficiency from 40.00% to 44.82%. Using a HPU with a 5.04 MW capacity can save $309,640 per each MW per quarter.

Prospects for increasing the efficiency of heat and electric energy-generation and heat-and-power supply at thermal power plants obviously draw attention to such modern and innovative technologies as heat pumps. Heat pumps allow efficient redistribution of energy flows. The abundance of low-potential heat carriers and heat sources in the cycle arrangement of the thermal power plants operation requires modernization of production and increase of the fuel heat utilization factor, therefore, reduction of specific fuel consumption for the production of heat and electricity. This paper analyzes the influence and practicability of introducing heat pumps into the heating circuit of the return water of the heat network of power units with PT-80 and T-250 turbines. Heat pumps of various configurations provide invariant energy conversion factor and efficiency. To assess energy and economic efficiency, modeling of the operation of power units and calculation of heat pump circuits for various refrigerants are performed. The economic effect is represented in quarterly cash savings of operating costs.

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The article presents the enlarged calculation and analysis of typical solutions of cogeneration plant`s heat network of CHP with cross-connections using the first phase of Avtovo CHP in Saint Petersburg as an example. As a way of CHP-15 cogeneration plant scheme optimization use of vapor compression heat pumps has been chosen and also lithium bromide absorption heat pumps to decrease the heat load of boilers in the deaeration plant. As a source of low-grade heat, a return heating water has been considered, and as a consumer – feed water of heating network.

The paper analyses operating and developing technologies for hydrogen implementation, transition, and storage at operating thermal power plants (TPPs) to make recommendations for realization of perspective projects for evaluation of the use of hydrogen as a fuel. Over the medium-term horizon of the next decade, it is suggested that using the technology of burning a mixture of hydrogen and natural gas in gas turbines and gas-and-oil-fired boilers in volume fractions of 20% and 80%, respectively, be implemented at operating gas fired TPPs. We consider the construction of the liquefied hydrogen and natural gas storage warehouses for the required calculated quantities of the gas mixture as a reserve energy fuel for operating the TPPs. We consider the possibility of the reserve liquid fuel system being replaced by the technology involving storage of liquefied hydrogen in combination with natural gas. An economic assessment of the storing cost of reserve fuel on the TPP site is given. The paper suggests that the methane-hydrogen mixture be supplied to the TPP site by two independent gas pipelines for the possibility of using the mixture as the main fuel and to exclude fuel storage at the plant.