Optimization of the cooling water mass flow rate under variable load of a power unit

Laskowski, Rafał; Smyk, A.; Rusowicz, А.; Grzebielec, Andrzej

doi:10.1016/j.applthermaleng.2021.116874

Cited by 11 publications

(3 citation statements)

References 34 publications

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“…Laskowski et al [26] analysed the effect of different cooling water mass flow rates on the thermal performance of a 225 MW thermal power plant in Poland within the load range of 40% to 100%. This study revealed that within a certain range, an increment in the cooling water mass flow rate led to an increment in overall power generation; however, it also resulted in a rapid increase in electricity usage by the cooling water pumps.…”

Section: Introductionmentioning

confidence: 99%

Influence of Cooling Water Parameters on the Thermal Performance of the Secondary Circuit System of a Modular High-Temperature Gas-Cooled Reactor Nuclear Power Plant

Wang,

Zhao,

et al. 2023

Energies

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This study quantitatively analysed the influence of cooling water parameters on the performance of a modular high-temperature gas-cooled reactor (MHTGR) nuclear power plant (NPP). The secondary circuit system and cold-end system were modelled using EBSILON software, version 16.0. The influence of cooling water inlet temperature and mass flow rate on the thermal performance of the secondary circuit system was analysed over the full power range with the goal of optimising net power. Under 100% rated condition, for each 1 °C increase in cooling water inlet temperature between 10 and 33 °C, the net power and cycle efficiency decreased by 0.67 MW and 0.14%, respectively, whereas the heat consumption rate increased by 28.72 kJ/(kW·h). The optimal cooling water mass flow rates corresponding to cooling water inlet temperatures of 16 °C and 33 °C were obtained. The optimal cooling water mass flow rate decreased nonlinearly with decreasing power levels. At a cooling water inlet temperature of 33 °C, an increase in cooling water mass flow rate from the designed value (7697.61 kg/s) to the optimal value (10,922.14 kg/s) resulted in a 1.03 MW increase in net power. These findings provide guidelines for MHTGR NPP operation optimisation and economic improvement, especially under high-temperature weather conditions.

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Section: Introductionmentioning

confidence: 99%

Influence of Cooling Water Parameters on the Thermal Performance of the Secondary Circuit System of a Modular High-Temperature Gas-Cooled Reactor Nuclear Power Plant

Wang,

Zhao,

et al. 2023

Energies

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“…In [5] author described research results concerning the cooling water flow control under the variable load of 200 MW steam turbine based on the minimum entropy and maximum power generation. In [6] the same author expands the research by including a new unit model and pump characteristics. This analysis confirms that below the 60% turbine load, the cooling water flow should be reduced.…”

Section: Introductionmentioning

confidence: 99%

Archives of Thermodynamics

Dobkiewicz-Wieczorek

2022

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This paper presents the influence of cooling water regulation on power plant net efficiency. It was examined whether, for the non-nominal low-pressure turbine load, it is justified to reduce the cooling water pump load, and how it would affect the unit net efficiency. Calculations for two types of power units were carried out: with condensing and extractioncondensing turbine. The tested condensing power plant consists of three surface condensers. The calculation included four condensers' connections set up on the cooling water side to check how the cooling water system pressure drop affects the net unit performance. The result has confirmed that implementing serial connection decreases net efficiency when cooling water flow regulation is used, but the mixed connection should be applied when pump load is not controlled. It was proved that the cooling water flow control gives a profit for both units. Net efficiency for combined heat and power plant can be improved by 0.1-0.5 pp, the gain is remarkable below 60% of the low-pressure turbine part load. Flow control implementation in the unit with condensing turbine water control gives a similar profit just below 80% of the turbine load. Next, an influence of the additional limitations of a cooling water system (minimal total pump head, cooling tower) affecting the feasibility of implementing the water control has been considered. Applying a multi-cell forced draft cooling tower does not have a significant impact on results, but when a natural draft cooling tower is used, the flow control range is strongly reduced.

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“…In this context the research focuses on how a change in operating conditions, particularly the load, of generation sources affects the performance of a power generation unit. For instance, in order to ensure an optimal operation of a unit, it is examined how properties of the cooling system [1][2][3][4] (temperature and the cooling water mass flow rate) affect the performance of the condenser, the cooling system, and the whole thermal system of the unit, or how steam properties (pressure, temperature) influence the efficiency and power output of the system [5][6][7][8]. Mathematical modeling employs mainly three fundamental equations, namely the mass balance, energy balance, and moment of momentum balance, which are used to work out pressure drops.…”

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confidence: 99%

Archives of Thermodynamics

Laskowski,

Smyk,

Ruciński

et al. 2021

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The paper presents formulas which can be used to determine steam condensation pressure in a power plant condenser in off-design conditions. The mathematical model provided in the paper makes it possible to calculate the performance of the condenser in terms of condensing steam pressure, cooling water temperature at the condenser outlet, and condenser effectiveness under variable load conditions as a function of three input properties: the temperature and the mass flow rate of cooling water at the condenser inlet and the mass flow rate of steam. The mathematical model takes into account values of properties occurring in reference conditions but it contains no constant coefficients which would have to be established based on data from technical specifications of a condenser or measurement data. Since there are no such constant coefficients, the model of the steam condenser proposed in the paper is universally applicable. The proposed equations were checked against warranty measurements made in the condenser and measurement data gathered during the operation of a 200 MW steam power unit. Based on the analysis, a conclusion may be drawn that the proposed means of determining pressure in a condenser in off-design conditions reflects the condenser performance with sufficient accuracy. This model can be used in optimization and diagnostic analyses of the performance of a power generation unit.

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Optimization of the cooling water mass flow rate under variable load of a power unit

Cited by 11 publications

References 34 publications

Influence of Cooling Water Parameters on the Thermal Performance of the Secondary Circuit System of a Modular High-Temperature Gas-Cooled Reactor Nuclear Power Plant

Influence of Cooling Water Parameters on the Thermal Performance of the Secondary Circuit System of a Modular High-Temperature Gas-Cooled Reactor Nuclear Power Plant

Archives of Thermodynamics

Archives of Thermodynamics

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