Xi'an Jiaotong University

Daotong Chong

Junjie Yan

Ming Liu

Hui Yan

Yongliang Zhao

Jinshi Wang

Weixiong Chen

Xin Li

Chaoyang Wang

Jiping Liu

Qinan Xing

In a high-efficient clean, high-variable load rate coal-fired power generation system, through the internal thermal source SCR denitration catalytic module coupled with high temperature and low temperature storage tanks, the operating temperature of the internal thermal source SCR denitration catalytic module is controlled in a range of 300&#xb0; C. to 400&#xb0; C., ensuring that the SCR catalyst has high activity in full-working conditions. Moreover, the high temperature and low temperature storage tanks are coupled with the high-pressure heater group for steam turbine regenerative system, so that when the coal-fired unit needs to increase load rate, the thermal storage energy is quickly converted into output power. In addition, energy stored in the high temperature and low temperature storage tanks come from both the internal thermal source SCR denitration catalytic module and the thermal storage medium heater within the boiler, the operational flexibility and the boiler efficiency are improved.

High-efficient clean, high-variable load rate coal-fired power generation system and operation method thereof

A solar-aided coal-fired flexible power generation system and an operating method thereof are provided. The system includes a coal-fired thermal power generation system and a high-temperature heat storage system coupled with solar thermal power generation; wherein a heat storage medium heater is arranged in the boiler flue; the flow rates of heat storage medium entering the solar heat collection device and the heat storage medium heater are adjusted by the regulating valve and the pump, eliminating irradiation fluctuation influences and maintaining stable power; a heat storage medium tank is used for peak shaving to reduce steam turbine output under stable boiler combustion; the flow and temperature of the feedwater entering the heat storage medium and feedwater heat exchanger are adjusted to realize rapid load cycling. The present invention can realize solar and coal-fired generation coupling, reduce coal consumption, and greatly improve the flexibility and economy.

Solar-aided coal-fired flexible power generation system and operation method thereof

A control method for optimizing a solar-to-power efficiency of a solar-aided coal-fired power system under off-design working conditions is provided. Through reading the relevant information of the solar collecting system, the coal-fired power generation system, the environmental conditions, and the working conditions of the solar-aided coal-fired power system, the water flow rate range able to be heated by the solar collecting unit and the solar-coal feedwater flow distribution ratio range are determined; through establishing the relationship between the solar-to-power efficiency and the solar-coal feedwater flow distribution ratio, the solar-coal feedwater flow distribution ratio is regulated, so that a flow rate of water entering the solar collecting system to be heated is controlled, thereby maximizing the solar-to-power efficiency and improving the economy of the solar-aided coal-fired power system. The present invention provides clear guidance to improve the utilization rate of solar energy and facilitate the consumption of the renewable energy.

Control method for optimizing solar-to-power efficiency of solar-aided coal-fired power system under off-design working conditions

A control method for optimizing generated power of a solar-aided coal-fired power system under off-design working conditions sets maximizing generated power without changing main steam flow rate as a control goal. A solar-coal feedwater flow distribution ratio is adjusted to adjust water flow rate heated by a solar heat collection system, so as to achieve the control goal. Control steps include reading relevant information; calculating the water flow rate range heated by the solar heat collection system, and an applicable solar-coal feedwater flow distribution ratio range; establishing a correspondence between the generated power and the solar-coal feedwater flow distribution ratio within this range; selecting a solar-coal feedwater flow distribution ratio corresponding to the maximum generated power; and adjusting the water flow rate entering the solar heat collection system to an optimized value. The present invention can flexibly control the solar-coal coupling and improve the economy.

Control method for optimizing generated power of solar-aided coal-fired power system under off-design working conditions

A solar aided coal-fired power generation system participating in primary frequency regulation and a control method thereof propose a system configuration with two regulation schemes by coupling medium-low-temperature solar collectors and a coal-fired generation unit. The two regulation schemes are a high-pressure feedwater bypass scheme and a low-pressure condensate bypass scheme. The present invention formulates a primary frequency regulation control logic, so as to efficiently and accurately participate in the primary frequency regulation, thereby keeping the power grid frequency rapidly stable. The present invention also formulates a working fluid outlet temperature control logic for the solar aided coal-fired thermal system, which adjusts a heat exchange working fluid flow of the solar collectors to ensure that the temperature in each section is stable during the primary frequency regulation. The present invention uses operation matching of the turbine system and the solar collectors to improve effectiveness of the primary frequency regulation.

Solar aided coal-fired power generation system participating in primary frequency regulation and control method thereof

A method for controlling a coal supply quantity during a transient load-varying process considering exergy storage correction of a boiler system of a coal-fired unit is provided. Temperatures and pressures of working fluid and metal heating surface of the boiler system of the coal-fired unit are measured and recorded in real-time, and converted into the exergy storage amount at different operating load points. During the transient operation process, the real-time exergy storage amount of the boiler system is compared with the exergy storage amount at the corresponding steady-state load point, and the real-time exergy storage variation is obtained; thereafter, the feed-forward control signal of coal supply quantity input is superposed to the existing coal supply quantity command of the boiler system, and the coal supply quantity signal of the boiler system based on the exergy storage correction is finally generated.

Method for controlling coal supply quantity during transient load-varying process considering exergy storage correction of boiler system of coal-fired unit

An optimized control method for a primary frequency regulation based on art exergy storage correction of a thermodynamic system of a coal-fired unit is provided. Through measuring and recording temperatures and pressures of working fluids and metal heating surfaces of the coal-fired unit thermodynamic system in real-time, an exergy storage amount of the thermodynamic system is obtained. During a transient process, according to an exergy storage variation before and after acting of each regulation scheme, a maximum power output of each scheme is obtained. Thereafter, through comparing the maximum power output with a power regulation quantity required by a power grid, an optimal primary frequency regulation control scheme is selected, so as to maintain a fast and stable grid frequency. The present invention reduces a selection blindness of the primary frequency regulation schemes, so that an operation flexibility of the coal-fired power unit during the transient processes is greatly improved.

Optimized control method for primary frequency regulation based on exergy storage correction of thermodynamic system of coal-fired unit

A flexible coal-fired power generation system includes a thermal system for coal-fired power generating unit and a high-temperature heat storage system connected in parallel, wherein: the heat storage system includes a heat storage medium pump (), a cold heat storage medium tank (), a hot heat storage medium tank (), multiple valves, and a heat storage medium and feedwater heat exchanger (). A heat storage medium heater () locates in the boiler () and is connected with both the cold heat storage medium tank () and the hot heat storage medium tank (). Through the heat storage medium pump (), the flow of heat storage medium that enters the heat storage medium heater () is adjusted to reduce the output of the steam turbine when the boiler () is stably burning.

Flexible coal-fired power generation system and operation method thereof

An all-condition auxiliary denitration system and an operation method thereof are provided. The system includes a heat-storage medium heater, a low-temperature reheater, an economizer, and an SCR denitration device which are successively interconnected, and further including a heat-storage medium tank and a heat-storage medium and feedwater heat exchanger. A flow of a cold heat-storage medium entering the heat-storage medium heater is regulated, so that heat absorption of the heat-storage medium is matched with a boiler load. Flows of hot heat-storage medium and feedwater, which enter the heat-storage medium and feedwater heat exchanger, are regulated through a feedwater regulating valve and a hot heat-storage medium outlet regulating valve. A total feedwater flow is regulated with assistance of a bypass feedwater regulating valve, so that a temperature of flue gas entering the SCR denitration device is kept in an optimal operation range under different boiler loads, and denitration efficiency is ensured.

All-condition auxiliary denitration system and operation method thereof

An analysis method of coal consumption of the thermal power unit during peak shaving transients includes measuring and recording the coal-feeding rate under different steady-state loads, and then establishing the relationship between the coal-feeding rate and the load, wherein the coal consumption index of the unit during transients can be directly presented by the difference between the real-time coal-feeding rate and a steady-state corresponding value; the total coal increment can be obtained by integrating the real-time coal-feeding rate increment with time; for different loads, the coal consumption increment due to the unit's thermal storage variation can be defined as the thermal storage coal consumption increment; the thermal storage deviation of the unit during transients causes the additional coal consumption, which is defined as the process control coal consumption increment. This work can provide the clear guidance for the fuel control of the thermal power unit during peak shaving processes.

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Shaanxi, China

Daotong Chong