SU1280099A1 - Arrangement for passing young fish through dam - Google Patents

Abstract

The invention relates to the field of hydraulic engineering and can be used in dams of medium and low pressure for the descent of young fish from the upper reach (WB) to the lower reach (HE). The device allows reducing injuries of young fish when descending from WB to NB. Fish through the dam 2 is made in the form of a straight pipe-confuser 1 of circular cross section with the law of diameter variation along the length d 41 uz d. where dg is diak X sinoi meter outlet 6 of the pipe-confuser 1; uz is the bypass difference jx distance from the outlet 6 to the calculated cross section; ob — the angle of inclination of the axis of the pipe-confuser 1 to the horizon. Pipe confuser 1 is fixed in the body of the dam 2. Moreover, its inlet 5 and outlet 6 have the same depth to the level of the free surface of the WB and NB, respectively. The fish passes through the device without experiencing a change in external pressure. 1 il.

Description

1128

The invention relates to the construction engineering and is intended for use in hydraulic systems of rivers of fishery importance.

The purpose of the invention is to reduce the trauma of young fish by providing constant pressure along the length of the pipe.

The drawing shows a device for the descent of young fish through the flesh, a section.

The device for lowering fish fry through the dam contains a confusor tube 1, fixed in the body of the dam 2 and connecting the upper 3 and lower A tail. The inlet 5 of the flue pipe 1 is buried beneath the level of the free surface of the headwater 3 at

the value of h | corresponding to the horizon of young fish. The outlet .6 of the pipe-confuser 1 is buried under the level of the free surface of the downstream 4 by the value h h |, i.e. it is under this condition that the young fish at the exit from the confuser tube 1 will experience the same external pressure as in the upper reach when entering the confuser tube 1.

The diameter of the pipe confuser 1 decreases from the inlet 5 to the outlet 6, and the diameter d of the cross section of the confuser along its length is determined from the ratio

 J | /

(one)

d d

 I

i. az X- Sinoi

where d. - diameter of the outlet 6; . uz - delta; X is the distance from the day off

holes 6 to the design section;

on - the angle of inclination of the pipe confuser 1 to the horizon. The device for the descent of young fish through the dam works as follows.

In the upstream 3 dams, 2 young fish during rolling migrations are carried by the water flow into the confusor pipe 1 fixed in the body of the dam 2. At the entrance to the confusing pipe 1 in the inlet 5, the young fish experience an external pressure corresponding to their depth of habitat hj. When moving through the pipe-confusor 1 in accordance with the law Returned

young fish will experience one

the sides increase the pressure from the burial below the level of the free surface of the upstream 3, on the other hand the decrease in pressure, due to the increase in the flow velocity in the confusing pipe 1 and friction losses.

At the outlet of the pipe-confuser 1 in the outlet 6 fish containing

 41

the stream has a velocity V - {2tj, - z. Since the rate of the conjugation of streams, permissible from the point of view of the absence of fish injuries, has certain values, for example, for an early young bream, which is most sensitive to: external influences Udd 12.5 m / s, for juveniles of most cyprinid fish of additional I .S m / s, this imposes restrictions on the scope

20 of this device by the magnitude of the difference of the diversions dg УUdr „/ 2§, 10 25

thirty

20 m. This, in turn, requires an insignificant length of the pipe-coifuser 1 and makes it possible to neglect friction losses.

Hence, with the law of changing the diameter of the pipe-confuser 1 in length, in accordance with expression (1), young fish moving in a stream of water will not experience changes in external pressure.

The flow of water in the confuser pipe I has a uniform velocity profile, which means that there are no prerequisites for the emergence of pulsation speeds and contacts of young fish with the surface of the confusor pipe 1, while maintaining; the speed of movement of the fish relative to the flow, pressure and gas saturation,

40, which makes it possible to completely eliminate the injury and death of young fish during descent through dam 2,

45

Claims (2)

112 The invention relates to engineering construction and is intended for use in hydraulic systems of rivers of fishery importance. The purpose of the invention is to reduce the trauma of young fish by providing constant pressure along the length of the pipe. The drawing shows a device for the descent of young fish through the flesh, a slit. The device for the descent of young fish through the dam contains a confused pipe 1, fixed in the body of the dam 2 and connecting the upper 3 and lower A blu fe. The inlet 5 of the pipe confuser 1 is buried under the level of the free surface of the upstream 3 by the value of h |, corresponding to the horizon of young fish. The outlet .6 of the pipe-confuser 1 is buried under the level of the free surface of the downstream 4 by the value h h |, i.e. It is under this condition that the young fish at the exit from the confuser tube 1 will experience the same external pressure as in the upper pool when entering the confuser tube 1. The diameter of the confuser tube 1 decreases from inlet 5 to outlet 6, while the diameter d of the cross section of the confuser along its length is not determined from the relation J | / X- Sinoi where d. - diameter of the outlet 6; . uz - delta; X is the distance from the outlet 6 to the design section; on - the angle of inclination of the pipe confuser 1 to the horizon. The device for the descent of young fish through the dam works as follows. In the upstream 3 dams, 2 young fish during rolling migrations are carried by the water flow into the confusor tube 1 fixed in the dam body 2. At the entrance to the confuser pipe 1 at the inlet 5, the young fish experience an external pressure corresponding to the depth of their habitat hj. When moving along the confusor pipe 1 in accordance with the law. The young fish will be returned to experience, on the one hand, an increase in pressure from burial under the free surface of the headwater 3, on the other hand, a decrease in pressure, from an increase in the flow rate in the confusing pipe 1 and friction. At the exit from the confuser pipe 1 in the outlet 6, the fish-containing stream has a velocity V - {2tj, - z. Since the rate of the conjugation of the streams, permissible from the point of view of the absence of fish injuries, has certain values, for example, for the early juvenile bream, the most sensitive to: external influences Udd 12.5 m / s, for juveniles of most carp fish, additional IS m / s, this imposes restrictions on the field of application of this device by the value of the diversion ratio dGUdr / 2§, i.e. 10 20 m. This, in turn, requires an insignificant length of the pipe-coifuser 1 and makes it possible to neglect friction losses. Hence, with the law of changing the diameter of the pipe-confuser 1 in length, in accordance with expression (1), young fish moving in a stream of water will not experience changes in external pressure. The flow of water in the pipe-confuser I has a uniform velocity profile, which means that there are no prerequisites for the occurrence of pulsating speeds and contacts of juvenile fish with the surface of the pipe-confuser 1, while retaining; fish flow speed relative to flow, pressure and gas saturation, which eliminates completely injury and death of young fish when descending through dam 2, the invention The device for descent of young fish through a dam, including an inclined tube of circular cross section connecting the upper and lower tails, characterized in that, in order to reduce the injury of young fish by providing a constant pressure along the length of the pipe, the pipe is made in the form of a straight line confuser, installed with the same depth. inlet and outlet openings; the diameter d of the confuser river section 1280099 along its length is determined from the ratio J, 4J A Z Q - a / 3 - and ------ 7. in I JZ - X. Sintl6 42 - X.sinti6 where d is the diameter of the outlet 5 is the diameter of the outlet of the confuser 5; 4 uz - difference of bulls; x is the distance from the outlet to the design section; "Angle of inclination of the confuser axis" angle n; to the horizon.