scholarly journals Application of extraction steam graded heat storage in peak shaving of condensing units

2021 ◽  
Vol 2087 (1) ◽  
pp. 012013
Author(s):  
Siyu Zou ◽  
Puyan Zheng ◽  
Qunzhi Zhu ◽  
Tianyu Bai ◽  
Qingyuan Wei ◽  
...  
Keyword(s):  
Working Condition ◽  
Heat Storage ◽  
Initial Conditions ◽  
Electrical Load ◽  
Two Stage ◽  
Peak Shaving ◽  
Boiler Load ◽  
Storage Structure ◽  
Steam Extraction ◽  
Regeneration Efficiency

Abstract In order to alleviate the peak shaving pressure of power grid and further improve the deep peak shaving capacity of coal-fired units, this paper applies staged heat storage to condensing units. Under the condition of constant boiler load, the heat of regenerative steam extraction is stored to reduce the electrical load output of the unit. Taking a 660MW ultra-supercritical unit as an example,30%THA,40%THA and 50%THA were taken as the initial conditions of heat storage respectively to discuss the peak shaving range and power regeneration efficiency of different extraction steam positions for heat storage. The results show that the “storage 1# HP heater extraction steam” scheme with “two-stage three tank” heat storage and release structure has the largest peak shaving range of 37.3%~56.9% under 50% initial conditions. When the “two-stage three tank” heat storage and release structure selects the “storage 1# HP heater extraction steam ”scheme under 40% initial working condition, the “power regeneration efficiency” reaches the highest——78.3%. And the “power regeneration efficiency” of “two stage three tank” storage structure are always higher than the “single-stage” storage structure.

scholarly journals Two-Stage Physical Economic Adjustable Capacity Evaluation Model of Electric Vehicles for Peak Shaving and Valley Filling Auxiliary Services

2021 ◽  
Vol 13 (15) ◽  
pp. 8153
Author(s):  
Dunnan Liu ◽  
Tingting Zhang ◽  
Weiye Wang ◽  
Xiaofeng Peng ◽  
Mingguang Liu ◽  
...  
Keyword(s):  
Electric Vehicles ◽  
Evaluation Model ◽  
Ancillary Services ◽  
Learning Ability ◽  
Time Sharing ◽  
Two Stage ◽  
Peak Shaving ◽  
Second Stage ◽  
Capacity Evaluation ◽  
Auxiliary Services

A large number of renewable energy and EVs (electric vehicles) are connected to the grid, which brings huge peak shaving pressure to the power system. If we can make use of the flexible characteristics of EVs and effectively aggregate the adjustable resources of EVs to participate in power auxiliary services, this situation can be alleviated to a certain extent. In this paper, a two-stage physical and economic adjustable capacity evaluation model of EVs for peak shaving and valley filling ancillary services is constructed. The main steps are as follows: with the help of the deep learning ability of the AC (Actor-Critic) algorithm, the optimal physical charging scheme of EV fleet is determined to minimize the grid fluctuation under the travel constraints of private EVs, and the optimized charging power is transferred to the second stage. In the second stage, load aggregators encourage users to participate in ancillary services by setting subsidy prices. In this stage, the model constructs a user decision model based on a logistic function to describe the probability of users accepting dispatching instructions. With the goal of maximizing the revenue of load aggregators, the wolf colony algorithm is used to solve the optimal solution of the time-sharing subsidy level, and finally the economic adjustable capacity of the EV fleet considering the subjective decision of users is obtained.

Analysis on Thermal Economy and Peak-Shaving Capability for Combined Heat and Power (CHP) Unit in Varying Operating Conditions

2014 ◽  
Vol 521 ◽  
pp. 508-515 ◽  
Author(s):  
Chun Guang Tian ◽  
Xiang Yu Lv ◽  
De Xin Li ◽  
Tian Dong ◽  
Xiao Juan Han
Keyword(s):  
Heat Supply ◽  
Consumption Rate ◽  
Calculation Model ◽  
Operating Conditions ◽  
Coal Consumption ◽  
Peak Shaving ◽  
Steam Extraction ◽  
Heat Quantity ◽  
Operation Test ◽  
Current Area

Based on the principle of featured through-current area being constant, calculation model for parameters of regenerative steam extraction of CHP unit in different heating conditions is developed in this paper through using FROTRAN software. The generated output and thermal economy of the CHP unit are calculated by using the method of equivalent enthalpy drop, and the accuracy of the model is verified. With the purpose to analyze the rationality of different calculation methods, the distribution ratio of coal consumption for heat supply and coal consumption rate for power generation are calculated through method of equivalent enthalpy drop, heat quantity method and method of actual enthalpy drop under the same operating condition. Moreover, according to the operation test on the unit, the highest and lowest generated output of the CHP under various loads of heat supply are determined, which will provide a basis to the subsequent thermoelectric units in participating in peak shaving of power grid.

scholarly journals Steady Solitary and Periodic Waves in a Nonlinear Nonintegrable Lattice

Symmetry ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 1608
Author(s):  
Igor Andrianov ◽  
Aleksandr Zemlyanukhin ◽  
Andrey Bochkarev ◽  
Vladimir Erofeev
Keyword(s):  
Numerical Simulation ◽  
Solitary Wave ◽  
Periodic Solutions ◽  
Initial Conditions ◽  
Periodic Waves ◽  
Two Stage ◽  
Second Stage ◽  
Ostrovsky Equation ◽  
Discrete Analogs

In this paper, stationary solitary and periodic waves of a nonlinear nonintegrable lattice are numerically constructed using a two-stage approach. First, as a result of continualization, a nonintegrable generalized Boussinesq—Ostrovsky equation is obtained, for which the solitary-wave and periodic solutions are numerically found by the Petviashvili method. In the second stage, discrete analogs of the obtained solutions are used as initial conditions in the numerical simulation of the original lattice. It is shown that the initial perturbations constructed in this way propagate along the lattice without changing their shape.

scholarly journals Evaluation and Simulation on the Reserve Capacity of Thermal Storage Electric Boiler Clusters

2020 ◽  
Vol 143 ◽  
pp. 02013
Author(s):  
Linjun Cai ◽  
Zheng Zhang ◽  
Dongliang Xie ◽  
Xiaofang Song ◽  
Yening Lai
Keyword(s):  
Renewable Energy ◽  
Storage Tank ◽  
Evaluation Method ◽  
Heat Storage ◽  
Power Grid ◽  
Renewable Energy Sources ◽  
Thermal Storage ◽  
Reserve Capacity ◽  
Peak Shaving ◽  
Electric Boiler

After providing a better service for nearby heating loads, a thermal storage electric boiler system can use the heat storage tank to participate in the peak-shaving and reserve services of the power grid. Current researches focus on its peak-shaving capacity, but ignores the use of its reserve capacity, which is important to the random fluctuations of renewable energy sources. Facing the actual analyzing demands on power system adequacy, this paper starts with the discussion of typical operation modes, and builds the powersystem- adequacy model of a thermal-storage electric boiler based heating system. Based on the presented model, the concept of feasible domain for heat charging and discharging is proposed. By implementing the concept, the quantitative evaluation method to calculate the reserve capacity of a thermal storage electric boiler system is proposed. The verification of the method is also given. Based on the planning data of an actual power grid, the short-term reserve capacity as well as the effect on promoting renewable energy consumption is estimated according to the given size of the provincial thermal storage electric boiler clusters. Finally, the influences of different choices of peak-shaving strategies, heat storage tank capacity on its reserve capacity are simulated and analyzed.

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