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Due to the complexity of thermodynamic system and variability of boundary condition, the striking non-linear relationship exists between the operating parameters and the energy consumption. At present, the research of quantitatively analyzing the problem under systematic variable work conditions is lack of effective method. Based on deep research on the problem, the concept of sensitive factors of the energy consumption of operating parameters was put forward. Furthermore, by the application of analytic models to the whole thermal system under variable work conditions and adoption of the state space theory, the topological relation between the parameters of the measuring points and the energy consumption was established. Then the non-linear analysis problem on the complex thermodynamic system under multi- boundary conditions can be availably solved. With analysis to the possible work conditions of different units, curves of the sensitive factors of energy consumption of all parameters are obtained. Through utilizing the probability density functions of load distribution, the total sensitive factor of energy consumption was defined. And the sequences of all operating parameterspsila sensitive factors of different units are obtained through calculation.

With the development of information and computer technology, it is possible to monitor and analyze on-line features of large steam turbine-generator units. Under premise of guaranteeing the unit operating safely, make the unit maintaining at optimal operating mode, thus maximally reduces the coal consumption is the practical request of market economy to the electricity generation enterprises. The choice operating mode is an important topic relates to the security and economic performance of unit. Base on the analyses of those existed calculation methods for turbine varying condition, we give a sequential varying condition calculation that starts with steam extraction of the final stage or the second final stage (superheated steam condition). According to the initially assumed final stage flow, and the thermodynamic parameters before the final stage, also the backpressure, we can distinguish the flow patterns of the stage by a discriminant criteria. Then we can conduct a stage varying condition calculation of primary stage in sequence from the front final stage parameter, so the new exhaust steam enthalpy and the heat consumption rate can be got. So the precise heat consumption rate and the exhaust enthalpy can be got easily. Furthermore, with the varying condition calculation based on this method, the mathematical model is built for selecting the optimal initial pressure of the coal-fired power unit, with the method of systemic analysis for the first time. That proposed a new method to optimize operation of the thermal power unit.

As a high level application module of SIS system, the on-line monitor and analysis system for energy-saving is widely applied to power plants. But the corresponding guide system which applied effectual guidance to realize optimal operation is still lack of sufficient research. The main purpose of the guide system is to confirm the certain reason which leads to energy loss among various reasons. Then the effective operating adjustment or timely maintenance could be implemented to reduce losses. As the symptoms, the operating parameters always depart from their target values. And the symptoms have determined logical relations with certain reason which leads to energy loss. With detail description of the function and structure of the guide system, the concepts of operating target value and parameterspsila offset degree are put forward in this paper for the first time. And the curves of some important parameterspsila operating target values are obtained by off-design condition analytic method with analysis of historical data. Furthermore, the logical matrixes which quantitatively describe the logical relations between symptoms and reasons are established by the method of symbolic logic. The research of the paper provides the important theory foundation to the exploitation of the guide system for energy-saving in power plant.

Due to the complexity of thermodynamic system and variability of boundary condition, the striking non-linear relationship exits between the operating parameters and the energy consumption. At present, the research of quantitatively analyzing the problem under systematic variable work conditions is lack of effective method. Based on deep research on the problem, the concept of sensitive factors of the energy consumption of operating parameters was put forward. Furthermore, by the application of analytic models to the whole thermal system under variable work conditions and adoption of the state space theory, the topological relation between the parameters of the measuring points and the energy consumption was established. Then the non-liner analysis problem on the complex thermodynamic system under multi-boundary conditions can be availably solved. With analysis to the possible work conditions of different units, curves of the sensitive factors of energy consumption of all parameters are obtained. Through utilizing the probability density functions of load distribution, the total sensitive factor of energy consumption was defined. And the sequences of all operating parameterspsila sensitive factors of different units are obtained through calculation.

As a high level application module of SIS system, the on-line monitor and analysis system for energy-saving is widely applied to power plants. But the corresponding guide system which applied effectual guidance to realize optimal operation is still lack of sufficient research. The main purpose of the guide system is to confirm the certain reason which leads to energy loss among various reasons. Then the effective operating adjustment or timely maintenance could be implemented to reduce losses. As the symptoms, the operating parameters always depart from their target values. And the symptoms have determinated logical relations with certain reason which leads to energy loss. With detail description of the function and structure of the guide system, the concepts of operating target value and parameterspsila offset degree are put forward in this paper for the first time. And the curves of some important parameterspsila operating target values are obtained by off-design condition analytic method with analysis of historical data. Furthermore, the logical matrixes which quantitatively describe the logical relations between symptoms and reasons are established by the method of symbolic logic. The research of the paper provides the important theory foundation to the exploitation of the guide system for energy-saving in power plant.

With the development of information and computer technology, it is possible to monitor and analyze on-line features of large steam turbine-generator units. The energy consumption rate and the exhaust steam dryness are two important indices. Base on the analyses of those existed calculation methods for turbine varying condition, we give a sequential varying condition calculation that starts with steam extraction of the final stage or the second final stage (superheated steam condition). According to the initially assumed final stage flow, and the thermodynamic parameters before the final stage, also the backpressure, we can distinguish the flow patterns of the stage by discriminant criteria. Then we can conduct a stage varying condition calculation of primary stage in sequence from the front final stage parameter, so the new exhaust steam enthalpy and the exhaust steam dryness can be got. So the precise energy consumption rate and the exhaust enthalpy (or the dryness) can be got easily. Obviously, without measuring the flow or the dryness, we can accurately monitor the on-line energy consumption rate and the dryness of the units.

Nowadays the examination and calculation of changeable behavior of steam turbine are still a technical difficulty which remains to be solved. In this thesis, the concept of stage current type is proposed, and criterion of differentiation of stage current type out of quantitative entropy currents is derived strictly from basic thermodynamic relation, therefore stage current type is found to be a built-in attribute of stage. The proposition of stage current type, the appearance of criterion of differentiation and the announcement of stage current type as a built-in attribute of stage enriched the theory of the examination and calculation of changeable behavior of steam turbine. Under the guidance of this theory, a new and concise method of calculating will be provided for the examination and calculation of changeable behavior of steam turbine.

One of the main shortages of thermodynamic system analysis in coal fired power plants is the lack of optimal value of initial parameters under present operating condition. In this paper, a mathematical model is given to solve the problem with the systemic analysis method for the first time. Through quantitative calculations of N300-16.7/537/537-3 unit of a certain thermal power plant, the optimal initial pressure is obtained by method of exhaustion. It is the foundation of the optimal control in the whole power plant. The limitation of optimal operation curve provided by manufactory is also analyzed in this paper.