Macroscopic Pressure Filtration Field in a Medium with Double Porosity

Journal of Engineering Physics and Thermophysics - This article presents a mathematical model of the pressure filtration field in a porous medium with a skeleton formed by two solid phases of...     

Application of SAW method for multiple-criteria comparative analysis of the reliability of heat supply organizations

Heat supply is the most energy-consuming sector of the economy. Approximately 30% of all used primary fuel-and-energy resources is spent on municipal heat-supply needs. One of the key indicators of activity of heat-supply organizations is the reliability of an energy facility. The reliability index of a heat supply organization is of interest to potential investors for assessing risks when investing in projects. The reliability indices established by the federal legislation are actually reduced to a single numerical factor, which depends on the number of heat-supply outages in connection with disturbances in operation of heat networks and the volume of their resource recovery in the calculation year. This factor is rather subjective and may change in a wide range during several years. A technique is proposed for evaluating the reliability of heat-supply organizations with the use of the simple additive weighting (SAW) method. The technique for integrated-index determination satisfies the following conditions: the reliability level of the evaluated heat-supply system is represented maximum fully and objectively; the information used for the reliability-index evaluation is easily available (is located on the Internet in accordance with demands of data-disclosure standards). For reliability estimation of heat-supply organizations, the following indicators were selected: the wear of equipment of thermal energy sources, the wear of heat networks, the number of outages of supply of thermal energy (heat carrier due to technological disturbances on heat networks per 1 km of heat networks), the number of outages of supply of thermal energy (heat carrier due to technologic disturbances on thermal energy sources per 1 Gcal/h of installed power), the share of expenditures in the cost of thermal energy aimed at recovery of the resource (renewal of fixed assets), coefficient of renewal of fixed assets, and a coefficient of fixed asset retirement. A versatile program is developed and the analysis of heat-supply organizations is performed by the example of the Republic of Tatarstan. The assessment system is based on construction of comparative ratings of heat-supply organizations. A rating is the assessment of reliability of the organization, is characterized by a numerical value, and makes it possible to compare organizations engaged in the same kind of activity between each other.