Study On Measures And Their Applications For Raising Water Head For Power Generation In Existing Hydropower Stations

As one kind of clean renewable energy source,hydropower shows great benefits in ecological terms.Looking back on the history of hydropower exploitation in China,it can be evidently observed that in the pre-developing stage during 1980s,due to limited technological level,finite ability of design and socioeconomic conditions of the day,inefficiency in both power generation benefits and ecological benefits tended to be common under the conditions of inadequately utilized water head,low efficiency of unit operation and unjustifiable layout of powerhouse in plenty of in-service hydropower plants.As for the post-developing stage under hydropower project management nowadays,hydropower development is increasingly constrained by ecological and environmental factors.Therefore,research and actualization aimed at quality-enhancement and efficiency-increase of plants in service,which may bring potential power into full play,absolutely are of great significance to improvement of ecological environment.This paper focuses on the study of measures of improving utilized water head of in-service hydropower plants and their application.The main contents of this paper are as follows.(1)Based on the development history of hydropower plants in China,three major measures of improving efficient utilized water head of in-service hydropower plants are proposed under the summarization of application status of engineering measures in flood-season scheduling optimization and utilized water head improvement:scheduling optimization of flood control level based on risk theory,tailwater level decrease in view of downstream dredging and amelioration of intake water flow conditions.And corresponding principles have been summed up systematically.(2)Applied in Huangtuxi reservoir,fitted regulation patterns of flood control level are assessed overall through a comparative study of quantitative calculation on flood risk as well as incremental beneficial effectiveness.It is insured that power generation benefits can be increased to a certain extent with water head being made full use of.(3)In view of a comparative study of tailwater level difference of Shuangpai hydropower station with a variety of units operation in stable period before and after tailwater scour,effects and benefits of downstream dredging by enhancing water head utility can be overall assessed.(4)Starting from the present condition analysis of intake flow in a desultorily mixed term that affects power generation benefits in Dongping hydropower station,a series of measures aimed at improving intake structures have been implemented in terms of numerical simulation and physical model test.And impact assessment has been conducted to the confirmation of the significance of amelioration of intake water flow conditions to utilized water head increase.Besides the measures of increasing utilized water head,there are yet other methods to enhance power generation benefits of hydropower stations in service such as improving performance and efficiency of generator set and optimized regulation on watershed scale.On the other hand,enhancement of ecological benefits can be actualized through improvement of water and soil conservation as well as strengthened management of water resources.A series of multitudinous factors is involved,of which certain factors tends to be mutually influential.Further research of concurrent results of those factors can be expanded forward.