SU1152999A1 - Method of protecting aqueous microorganisms,embrios and young fish from peril of cavitation in water ducts of hydraulic structures - Google Patents

Abstract

SPSYUOB PROTECTION YUDNYH MICROORGANISMS, embryos and young fish from death from cavitation in the duct of hydraulic works, vklyuchakschy supply air conduit, characterized in that, in order to increase the protection efficiency over the air conduit is carried out before the cavitation zone until uniform nasscheni water by the entire section of the conduit. (L

Description

The invention relates to hydropower engineering and nature protection and can be used in hydroelectric power plants (HPPs), pumped storage plants (PSPPs) and pumping plants. It is known that large pressure pulses have a destructive effect on animal and plant biological objects inhabiting aquatic GO. Under natural conditions, the water flowing through the hydromachine from the reservoir has a certain number of air bubbles per unit of small size (10 -10 cm). The volumes of water flowing through the zones of tensile stresses of the hydraulic machines undergo a rupture in the air bubble, which grows, filling with steam. Then, this steam puff, entering the zone of higher pressure, is compressed, the steam condenses, and as a result, pressure impulses of several thousand h kg / cm are produced, from which high-alloyed steels are destroyed in the cavitating zone and live organisms die. This process of growth and closure of cavitation bubbles is called steam cavitation. Studies have shown that the operation of hydro-machines of a hydroelectric station, a power plant and pumping stations is accompanied by steam cavitation of different intensities depending on the type of hydraulic machine and its operating modes. Since practically the entire flow of large rivers and the water supply in reservoirs flows through the hydraulic machines of steam cavitation often leads to mass death of microorganisms, embryos and fry of fish, which with the flow of water pass between the blades of impellers and are subject to intense cavitation. I There is also known a method for protecting aquatic microorganisms of embryos and fingerlings of fish from death due to cavitation in water conduits of hydraulic structures, including the supply of 12J air into the conduit. This method reduces the cavitation phenomena in the water conduit, which reduces the death of microorganisms, but since it is impossible to completely eliminate cavitation, the death rate is quite high. The purpose of the invention is to increase the effectiveness of protection. This goal is achieved by the fact that according to the method of protecting aquatic microorganisms, embryos and fry of fish from death due to cavitation in water conduits of hydraulic structures, including the delivery of air into the water conduit, the air in the water passage is carried out before the cavitation zone until the water is evenly distributed throughout the water conduit. Neither figure 1 shows a hydroelectric power station, a cross-section; in FIG. 2, an experimental experimental characteristic of a communication of a relative value (,%) of the death of microorganisms depending on the intensity of the cavitation effect (W / cm). The table shows approximate digital data on the dependence of the death of microorganisms on the magnitude of the intensity of the cavitation effect (relative number of dead microorganisms, etc. J). Microbial Aggregation Accelerates Medium Microbial Mobility 3 Note: Note. dead microorganisms, etc .; 51.P - the total number of microportan mov.

From compressor 1, atmospheric air is supplied through pipe 2 through the most convenient opening in the rpe6ite dam, which is located close to the pressure pipeline 3. Through the socket 4, air is admitted into the water flow with minimal yield losses, i.e. with the least pressure pulsations. Then the air is mixed, the passage of the pressure pipe 3, the spiral chamber 5 and the guide apparatus 6 and enters the blades of the impeller 7, evenly distributed in the water flow in a dispersed state

Measurements of the intensity of the cavitation effect are carried out using a hydrophone 8 and a harmonic analyzer 9.

From compressor 1 through pipe 2, a certain flow of air into water Qg is supplied, and at constant values of head and suction height (H const, H5 const), the intensity of the cavitational effect I is determined and a biological water sample is taken in the inlet area, in the pressure pipe and on The discharge from the suction pipe of the hydromachine. Such experiments were carried out at various values of the power of the unit, i.e. under different conditions of the cavitation effect of the hydraulic machine, the IKROKORGAYISM et al., which flow with the water through the cavitation zone.

The same tests were carried out at other air flow rates in water, including. Then, when changing the operating head H and the suction heights H5 (at other times of the year), other test cycles were performed at the same values of the unit load (water flow). After obtaining a sufficient amount of material, technical and economic calculations were performed, determining the optimum air quality required for feeding into the hydromachine to significantly reduce the death of microorganisms, etc.

PRI me R. The intensity of the cavitation effect of high-pressure radial-axial hydraulic turbines, depending on the mode of operation, varies from about 0.5 to 10 W / cm. This corresponds to low, medium and high intensity of exposure (see I. Mataušek. Ultrasonic technology. M., GNTIL for Ferrous and Nonferrous Metallurgy, 1% 2, p. 107-109, ta5l.1), W / sn may cause mass death of microorganisms. If the water entering the hydromachine is filled with free air to 0.1% or the volume content of air in the water, the intensity of the cavitation effect decreases due to the change in the wave resistance of the mixture of water and air ff. 3-4 times, excluding dangerous levels., cavitation effects. The absence of death in the coping was checked in a known manner, determining the mobility of microorganisms in samples taken before the cavitirure zone and behind the impeller.

Uniform distribution of air in water and air flushing of air reduces the intensity of the cavitation effect on microorganisms, etc. and, with a sufficient amount of air in the water, eliminates their death, using the method with the use of acoustic measurements reduces the time required for conducting field experiments to determine the optimal amount of air supplied to the water. Reducing the death of Juvenile organisms, etc., increases the productivity of the fish economy of rivers, reservoirs and canals and restores their ecology.

Claims (1)

METHOD FOR PROTECTING WATER MICROORGANISMS, EMBRYONS AND FISH SMOKES FROM DIECE DUE TO CAVITATION IN HYDRAULIC STRUCTURES, including supplying air to the water conduit, characterized in that, in order to increase the efficiency of protection, air is supplied to the water conduit to the zones before the zones section of the conduit.