Abstract
In Northern China, due to the high penetration of coal-fired cogeneration facilities, which are generally equipped with extraction-condensing steam turbines, lots of wind power resources may be wasted during the heating season. In contrast, considerable coal is consumed in the power generation sector. In this article, firstly it is revealed that there exists a serious divergence in the ratio of electrical to thermal energy between end users’ demand and the cogenerations’ production during off-peak load at night, which may negate active power-balancing of the electric power grid. Secondly, with respect to this divergence only occurring during off-peak load at night, a temporary proposal is given so as to enable the integration of more wind power. The authors suggest that if the energy carrier for part of the end users’ space heating is switched from heating water to electricity (e.g., electric heat pumps (EHPs) can provide space heating in the domestic sector), the ratio of electricity to heating water load should be adjusted to optimize the power dispatch between cogeneration units and wind turbines, resulting in fuel conservation. With this proposal, existing infrastructures are made full use of, and no additional ones are required. Finally a numerical simulation is performed in order to illustrate both the technical and economic feasibility of the aforementioned proposal, under ongoing infrastructures as well as electricity and space heating tariff conditions without changing participants’ benefits. The authors aim to persuade Chinese policy makers to enable EHPs to provide space heating to enable the integration of more wind power.
Highlights
In order to meet the abundant space heating demand efficiently, district heating and coal-fired cogeneration units equipped with extraction-condensing steam turbines have been encouraged
I 1 where Qi (MW) is the new thermal power generated from the ith cogeneration; COP is the coefficient of performance of the corresponding electric heat pumps (EHPs); positive PEHP (MW) is the electrical power consumed by the EHPs for space heating purpose; Pi (MW) is the new electrical power generated from the ith cogeneration; PWIND (MW) is the additional wind power utilized; WIND is the efficiency of the wind turbines (0.95)
Because the authors’ proposal is only focused on enabling more wind power integration during off-peak load at night 0:00~7:00 o’clock, the tradeoff of choosing EHPs should be considered in practice
Summary
In order to meet the abundant space heating demand efficiently, district heating and coal-fired cogeneration units equipped with extraction-condensing steam turbines have been encouraged. Northern China covers the northwest grid, north grid and southeast grid [4,5] This can be attributed to the fuel conservation which may be obtained based on coal-fired cogeneration units [6]. End users’ load patterns of electricity and space heating have not been considered to be adjustable for optimizing the dispatch between cogenerations and wind turbines, which can help to. Gross electrical and thermal energy production seem to be adjusted so as to optimize the dispatch between coal-fired cogeneration facilities and wind turbines, which depends on the practical performance of cogenerations in Northern China and results in a critical coefficient of performance (COP) of electric heat pumps introduced.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have