Continuous measurement method for local atomized rain intensity of multi-working condition discharge under low pressure environment

Abstract

The invention discloses a method for continuously measuring multi-working-condition discharge local atomization rain intensity in a low-pressure environment. The method comprises steps of 1) preparation work before testing; 2) measuring the atomization rain intensity under the normal pressure working condition; 3) measuring the atomization rain intensity under the low-pressure working condition; and 4) after measurement is finished, making a low-pressure tank supplement the air and drain the water. A testing device structure is designed on the basis of the bus dividing and converging principle, and testing precision and efficiency are optimized and controlled; the average rain intensity improves test precision of the water collection duration by changing the range of a timer, the instantaneous rain intensity regulates and controls the test range and duration by designing a rain gauge, a communicating pipe, a high-level liquid level controller, a low-level liquid level controller and awater suction pump in match with a measuring cylinder, and the principle is clear; a measuring device is integrally installed in a low-pressure box, air pressure difference protection does not need tobe considered, manufacturing cost can be saved, machining difficulty can be reduced, and structural safety of the low-pressure box can be guaranteed. The method is advantaged in that a basis can be provided for high-quality and high-efficiency testing of multi-working-condition discharge local atomization rain intensity distribution characteristics in the low-pressure environment.

Description

technical field [0001] The invention belongs to the technical field of dam engineering hydraulic tests, in particular to a method for continuously measuring local atomized rain intensity of multi-working-condition discharge in a low-pressure environment. Background technique [0002] When a hydropower station discharges, it will produce rain and fog, which is called discharge atomization. Leakage atomization is a complex water-air two-phase flow problem. Under the space-time accumulative effect of high-intensity short-duration, low-intensity long-duration, and high-intensity long-duration atomized rain, leakage and atomization hazards such as slope instability, plant flooding, blocked traffic roads, and damaged transmission lines directly threaten Engineering safety. Compared with the global prediction and protection of fogging rain, the local fogging rain intensity test is carried out in typical areas in the near and far areas of fogging, which can intuitively and accurat...

AI Technical Summary

Problems solved by technology

It has been reported in the literature that the normal pressure test arranged outside the water cushion area can measure the average atomized rain intensity by using the measuring cylinder to collect and weigh, but it is not suitable to extend to the low pressure environment test and the instantaneous characteristics of the atomized rain intensity cannot be obtained because the low pressure The box is closed, and no one can enter during low air pressure; and the test process is difficult to control, stable water flow-air pressure test conditions need to be debugged, and invalid atomized rain will converge during the debug process, resulting in inaccurate tests

The test in a low-pressure environment outside the water pad area is mentioned in a patent. The precipitation measuring instrument described in the existing patent document CN208937287U is arranged under the drainage pipe of the inclined manifold and the precipitation measuring instrument is single, which can meet the requirements of the patent. The above-mentioned aeration-atomization characteristic parameter set measurement requirements; but it is not suitable to be arranged on the water pad area, because the layout space of the precipitation measuring instrument is limited, and it cannot meet the local area atomization of multi-working conditions discharge atomization Determination of instantaneous characteristics of rain intensity, because the range of a single precipitation measuring instrument is limited

During the low-pressure test, if the test equipment cannot meet the continuous measurement requirements of multiple working conditions, frequent opening and closing of the pump unit in a limited time is not conducive to the long-term stable operation of the test system, and will cause a lot of waste of manpower and material resources; If the cycle encounters seasonal alternation, it is easy to introduce large changes in temperature and other environmental factors to interfere with the test results, which is not conducive to the repetition and analogy of similar working conditions; moreover, the test area in a low-pressure environment is limited, so it is necessary to consider when using test instruments. Whether the instrument is affected by the low pressure environment and the effective correction method also needs to take into account its water resistance and pressure resistance; the current test method has not yet solved the continuous measurement of the local atomized rain intensity of the multi-working condition discharge in the low pressure environment. Therefore, It is necessary to design a continuous measurement method for local atomized rain intensity of multi-working condition discharge under low pressure environment

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