Intake Temperature Calculation And Control Scheme Analysis Of Air-conditioning Water System In Underground Hydropower Plant

In the 21st century,with the increasingly prominent energy crisis,hydropower has the natural advantages of large power generation,stable and reliable,clean and renewable,and occupies an important position in the global energy market.Since the establishment of China’s first hydropower plant at the beginning of the 20 th century,it has a history of100 years.During this period,China attaches great importance to the development and utilization of water resources,and has established a number of hydropower plants,which play an important role in China’s energy system.The main function of hydropower plant is to produce electricity through water power,which needs to provide a suitable environment for the normal operation of equipment and the work of personnel in the production process.Due to the limitation of natural conditions,hydropower plants are mostly buried in the ground.The heat and moisture load in underground powerhouse of hydropower plant is large,so ventilation and air conditioning has become a necessary means of air conditioning in the plant.In recent years,there are many researches on the ventilation and air distribution in hydropower plant,and the water system in the air conditioning system of hydropower plant is also worthy of attention and research.Firstly,this paper summarizes and analyzes the space layout and load characteristics of underground hydropower plant.Including the layout characteristics of the underground powerhouse,the main causes of the load in the plant and the load characteristics in the plant,through literature and engineering research,the main load components and load changes of the hydropower plant are analyzed.Secondly,the water intake path and air conditioning system of hydropower plant affect the design of water intake system.In order to obtain the temperature of water system air conditioning intake,this paper starts from the simulation calculation method of reservoir water temperature,summarizes the mainstream calculation methods of reservoir water temperature distribution,analyzes the parameters,applicable conditions,advantages and disadvantages of various methods,and summarizes the calculation steps of reservoir water temperature of hydropower plant.After selecting the appropriate method to calculate the water temperature distribution of the reservoir,it is necessary to consider the influence of water intake path on the water temperature entering the airconditioning equipment.This paper summarizes the water intake source,process and location of the existing air-conditioning water system of hydropower plant,further considers the heat transfer factors of each link,establishes the calculation model of water inlet temperature rise of air-conditioning water system of hydropower plant through analysis,and calculates through an example The calculation shows the value of inlet water temperature rise in the project.The air conditioning water system of underground powerhouse of hydropower plant underground hydropower plant has its own characteristics compared with the conventional air conditioning water system due to the difference of water sources.This paper summarizes the main characteristics of the air-conditioning water system of hydropower plants and the composition of the air-conditioning water system of some built hydropower plants;The intake water temperature affects the design and operation regulation of the air conditioning system of hydropower plant,and affects the system form and water quantity,which is the key parameter for the design and regulation of the pipe network.Therefore,the hydraulic characteristics of the air conditioning water system are analyzed,and the common methods of hydraulic imbalance and hydraulic balance are summarized,it is qualitatively concluded that the constant pressure difference control method is suitable for the variable flow chilled water system and the constant temperature difference control method is suitable for the variable flow cooling water system.Finally,this paper focuses on the quantitative analysis of the optimal control strategy of the air conditioning water system of hydropower plant.Based on the resistance model of the actual air-conditioning water system pipe network,combined with the performance of variable-frequency pumps,input power,energy consumption equation of multiple variable-frequency pumps in parallel and variable-speed adjustment range of pumps,taking the parameters of air-conditioning water system of a hydropower plant in an actual project as the calculation basis,the energy saving of different differential pressure control methods and the stability of water system under different pipe network forms are analyzed.It is concluded that the fixed end pressure difference control and the same program pipe network at the end are the better water system control and layout methods.At the same time,combined with the characteristics of underground hydropower plant,the water system control schemes under different load modes are described.