Control System of Substance and Energy Balances of Combined Heat-and-Power Plants Applying the Least Squares Adjustment Method

Abstract

The set of substance and energy balance equations of water and steam collectors, together with the balance of boilers and turbines (including the regeneration system) is the base of the control system of the exploitation of a combined heat-and power plant. The initial values of this system are the results of measurements in the course of exploitation. Due to inevitable errors in the measurements the substance balances display discrepancies between the balance of steam and the balance of the feed water, and the calculated technical indices are uncertain. In order to increase the reliability of the results of the technical analysis of exploitation and to co-ordinate the balance equations we may use the least squares adjustment method. It may be applied on the condition that we have a sufficient surplus of measuring data. The number of balance equations must be higher than the number of unknown values. This makes it possible to apply the criterion of least squares warranting a maximum of the reliability function in an n dimensional. space of errors (n - number of measuring data). This method has been applied in the balance systems of the combined heat-and-power generating plant.

Keywords

• control system, substances and energy balances, combined heat and power plant, least squares adjustment method