Principles and Contents of Hydraulic Turbine Selection and Design

Today, China Francis Turbine Supplier will introduce the principles and content of turbine selection and design.

1. Information required for turbine selection

Before selecting a turbine, in addition to understanding the guidelines and policies of hydropower construction in various countries, the following data and parameters should be collected: (1) Planning of water conservancy and hydropower and parameters related to the size of the power station: understand the hydrology, geology, and river development of the basin where the hydropower station is located Methods, reservoir regulation performance, power station type, and hub arrangement. Grasp the head and flow characteristic parameters, such as the maximum head, minimum head, average head, design head, maximum flow, average flow, installed capacity, and the relationship between the elevation of the power station and the water level flow curve downstream of the power station. (2) Information of the power system where it is located: such as the capacity of the power system, the load situation, the nature of the user, the role and status of the designed power station in the system, and the requirements of the system on the designed power station. (3) Technical information of turbine products: such as spectrum information, parameters and performance of turbine models, and technical information of similar power stations. (4) Local construction and transportation conditions.

2.Hydraulic Turbine Generator selection principle

The selection principle of the hydraulic turbine is to select a hydraulic turbine with good performance and small size under the conditions of meeting the output requirements of the hydropower station and adapting to the parameters of the hydropower station (head and flow). The so-called good performance includes two aspects of good energy performance and good cavitation resistance. Good energy performance requires high efficiency of the turbine, not only the highest efficiency of the turbine, but also its average efficiency when the head and load change. For this reason, a turbine with a gentle curve change should be selected as much as possible within the range of the hydropower station's head change. The cavitation resistance is good, that is, the cavitation coefficient of the selected turbine should be small, which can ensure the stable and reliable operation of the unit. In order to make the size of the water turbine small, a water turbine with a higher specific speed should be selected as much as possible. The water turbine with a higher specific speed has a higher rotational speed and a smaller diameter of the runner. For this reason, when the turbine is selected and calculated, the unit speed should be equal to or slightly higher than the optimal unit speed, and the value should be the maximum unit flow rate recommended in the spectrum table to make full use of the water passing capacity of the turbine and reduce the size of the turbine. . In addition to considering the above basic principles for selecting a turbine, you should also consider that the selected unit is easy to supply, has small transportation difficulties, and is convenient for construction and installation, so as to shorten the construction period of the hydropower station as much as possible and strive for early power generation.

China Pelton Turbine

3. Turbine selection

The procedure for selecting a turbine is basically to first formulate several possible alternatives, to obtain and compare the kinetic energy economic indicators of each alternative, and finally to determine the best solution through optimization. For each candidate, the main contents of the turbine selection are:

1. Select the number of units and single capacity;

2. Select the model and installation method of the turbine;

3.Determine the runner diameter and speed of the turbine;

4.Determine the maximum allowable suction height and installation elevation of the turbine;

5.Draw the comprehensive characteristic curve of hydraulic turbine operation (generally provided by the manufacturer);

6. Determine the form and size of the volute and the draft tube;

7. Select governor and hydraulic device.

The above is the principle and content of turbine selection design introduced by China Pelton Turbine Supplier.