Energy efficiency of operational regimes of combined heat and power plants of industrial enterprises

Abstract

Enterprises with energy-intensive production have combined heat and power plants (CHP) in their structure. During the implementation of energy saving measures, it is possible to achieve different ratios between the indicators of the efficiency of consumption of thermal and electrical energy by enterprises for production. With certain ratios between specific heat and electricity consumption in production, the enterprise is forced to buy a certain part of the electricity in the district power system (DPS) to prevent the discharge of steam exhausted by the turbine into the atmosphere or to deliver excess electricity of its own generation to the DPS. The problem cited in the article indicates that the choice is determined by the prices for fuel for CHP and the ratio between the prices for electricity purchased in the DPS and delivered to the DPS. Although electricity consumption in the production of sugar does not exceed 11% of the energy of the fuel, it is profitable to generate it in excess (turbine generators operate at maximum, close to the nominal mode) and deliver it to the distribution zone at a price higher than the cost. The proposed method for selecting operating modes for CHP turbine plants using the example of a sugar plant, which can also be used for the construction industry, as well as a method for determining energy costs for all operating modes of a sugar plant turbine plant. The influence of the cost of electricity in the distribution zone on the choice of the mode of operation of turbine plants of the CHP, which provide the minimum financial costs for the energy supply of the enterprise, has been established. A method for determining the standard size of a CHP turbine plant that satisfies the specific indicators of heat and electricity consumption of an enterprise is presented.