Method of calculation and design of the ice and thermal regime of the lower pools of hydroelectric stations

Conclusions

• 1. The problem of calculating and predicting the ice and thermal regimes of modern large hydrostations being created, especially under northern climatic conditions, is important for solving many problems having national economic and nature conservation significance. The solution of the problem of reliable prediction of ice and thermal regimes in lower pools of large hydrostation is of particular interest and significance.

• 2. The presently existing methods of calculating the ice and thermal regime of pools of hydrostations are approximate and have been developed mainly with regard to the operating conditions of particular low- and medium-head hydrostations located, as a rule, in the temperate climate zone. They insufficiently take into account the specific characteristics of the physical phenomena governing the formation of the ice and thermal regime in lower pools.

• 3. As shown in the article, on the basis of an additional thorough study of physical phenomena with the use of data of actual observations it is possible to give a reliable picture of ice and thermal processes in lower pools of hydrostations, including those located under northern climatic conditions. With the use of the theory of heat transfer and refinement of the heat-balance equations analytic and graphic relations were obtained which permit determining the main characteristics of the ice and thermal regime in various stretches of the lower pool, longitudinal and vertical temperature distribution of the flow, and formation of frazil and the ice cover.

In the future these relations can be refined with the use of mathematical modeling methods, comparison with actual data, and also with consideration of the possible effect of various additional factors in the lower pool (presence of the discharge of warm waters, unsteady flow regime during operation of the hydrostation, etc.).