Features of the Use of Liquefied Petroleum Gas as a Reserve and Alternative Fuel at Coal-Based CHP Plants

Abstract

The paper analyzes the main properties of liquefied petroleum gas and the peculiarities of its energy use compared to natural gas, including taking into account the specifics of the operation of pulverized coal boiler units of the CHP. The advantages of liquefied petroleum gas compared to heavy fuel oil are shown and a comparative economic assessment of their use is given. It is shown that interchangeability with natural gas is ensured by mixing the vaporized liquefied petroleum gas with air to form a homogeneous mixture — synthetic natural gas, which can be directly used in burners as a direct substitute for natural gas without changes in the composition of the equipment and in the design of the boiler burners. The calculation is presented of the permissible limits of the air fraction for liquefied petroleum gas of different composition according to the criterion of the Wobbe Index correspondence of synthetic natural gas and natural gas. Technical solutions are proposed for the use of liquefied petroleum gas as a reserve and alternative fuel at coal-fired combined heat and power plants in the event of damage of gas supply networks, which provide reliable and economical feeding of a coal-fired boiler unit with synthetic natural gas in such fundamentally different modes as coal jet “lighting” with low consumption and pressure of synthetic natural gas and ignition or emergency operation at a load of 25 % with high consumption and increased synthetic natural gas pressure, with the possibility of switching from natural gas to liquefied petroleum gas and vice versa. Bibl. 17, Fig. 3, Tab. 5.