Flow guide type inlet structure of drainage cooling section of heater and design method

Abstract

The invention discloses a flow guide type inlet structure of a drainage cooling section of a heater and a design method. A plurality of flow guide blade grids are arranged on an upstream side drainage cooling end plate of the drainage cooling section of the heater and a downstream side drainage cooling end plate of the drainage cooling section of the heater, so that flow guide blade grid channels with equal outlet through-flow areas are formed, drainage hole outlets are evenly formed in the upper portions of the flow guide blade grid channels, drainage hole inlets are formed in the lower end face of the upstream side drainage cooling end plate of the drainage cooling section of the heater and the lower end face of the downstream side drainage cooling end plate of the drainage cooling section of the heater, the arrangement of drainage holes fully utilizes differential pressure power at the inlets and the outlets, and drainage water in the high-pressure area at the inlet of the drainage cooling section can directly reach the inside of the drainage cooling section under the driving of the pressure gradient, so that the siphoning capacity of the drainage cooling section is further improved, and finally, the performance of a siphoning structure and the stability of a low-siphoning structure are improved.

Description

technical field [0001] The invention belongs to the field of steam turbine power generation, and in particular relates to an inlet structure and a design method of a flow-guided heater's drain cooling section. Background technique [0002] At present, the regenerative cycle is widely used in the system design of large thermal power plants, and the regenerative cycle is realized by configuring the feed water heater. The feedwater heater is an important equipment to improve the economy of thermal power plants. According to the different steam-water heat exchange methods in the feedwater heater, it is usually divided into superheating section, saturated section and cooling section in structure. The superheated section of the heater uses the sensible heat of the superheated extraction steam of the steam turbine stage to heat the feed water in the shaped pipe. After the steam is deflected in multiple ways through the partition, the superheated steam will be cooled to 25°C-30°C hi...

AI Technical Summary

Problems solved by technology

Currently affected by factors such as power peak regulation, the operating conditions of the generator set are complex. The heater must not only operate under rated conditions, but may also be affected by various abnormal conditions. Therefore, the water level of the heater will fluctuate significantly. Fluctuation phenomenon

The commonly used cold-draining section of the heater is a single-channel planar end wall design. When the working condition changes and the water level of the heater fluctuates, the equilibrium state of the siphon structure is easily destroyed, and part of the steam in the saturated section will enter the cold-draining section. , which leads to the occurrence of vapor-liquid two-phase flow phenomenon, which increases the difference between the hydrophobic ends of the heater, which in turn intensifies the erosion of the tube wall of the next stage heater, thus making the tube wall thinner, and in severe cases, safety accidents such as tube bursts occur

Images