Method for improving uniformity of flow distribution of heat collector of parabolic trough solar thermal power generation system

Abstract

The invention belongs to the technical field of solar heat utilization and discloses a method for improving uniformity of flow distribution among parallel-connection pipelines of a heat collector of a parabolic trough solar thermal power generation system. According to the method, on the basis of the structural characteristic of a direct steam generating system in the parabolic trough solar thermal power generation system, parallel-connection pipeline physical models with the same inlet and outlet headers and pressure drop calculation models of flow in a single-phase area and a double-phase area in the single pipeline are set up; pressure drop along a path in the single pipeline is calculated for obtaining a relation curve of the change of the pressure drop along with flow, and by means of analysis of two pipes, the reason for nonuniform flow distribution is judged; throttling pipe rings are installed on the unheated portions of inlets of all parallel-connection branching pipes respectively, and the size of the drift diameter of throttling pipes is determined by the specific operation conditions. According to the method, the flow resistance characteristic is changed due to additional arrangement of the throttling pipe rings, pressure increase, caused by steam, of the gas phase area and the liquid phase area is offset, and flow is distributed uniformly. The device is high in safety, simple in structure, low in manufacturing cost and high in practicality.

Description

technical field [0001] The invention belongs to the technical field of solar heat utilization. In particular, it relates to a method for improving the flow distribution uniformity of a heat collector of a trough solar thermal power generation system. Background technique [0002] The trough solar thermal power generation system mainly includes a double loop system and a direct steam generation system (Direct Steam Generation, DSG). A dual circuit system includes a thermal fluid circuit and a water-steam circuit. The heat transfer oil converts the solar energy absorbed in the vacuum heat collecting tube into heat energy, and then transfers the heat to the water through the heat exchange equipment to generate steam, thereby driving the steam turbine to do work to generate electricity. The DSG system is a single-loop system, that is, water is used as the heat-absorbing medium to generate steam through the vacuum heat collecting tube once to drive the steam turbine to generate...

AI Technical Summary

Problems solved by technology

The main reason is the lack of understanding of the flow characteristics of the two-phase flow in the collector pipe, resulting in a series of instability problems including uneven flow distribution, which has become an obstacle to the application of this technology

Among them, the uneven flow distribution in the collector will directly affect the stability of the outlet steam parameters, and will even lead to accidents such as bending and rupture of the collector pipe due to uneven heating

There is no published research results on this issue in China

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