Background technique
Erosive wear and cavitation erosion are the generally existing engineering problems of hydraulic outlet works.Statistics shows, I
There is punching mill and cavitation erosion in the large hydraulic engineering sluicing facility of 70% or more state, especially in recent years not with project scale
Disconnected to expand, sluicing stream has reached 50m/s grades of ultra high rate under high dam, and the mill Cavitation mesh benefit of rushing of discharge structure protrudes.
Therefore, to solve this engineering challenge, the research about high performance hydraulic conerete erosion resistant did not stop always,
Excellent erosion resistant continues to bring out, and needs to carry out the investigation and evaluation of resistant abrasion cavitation prevention performance for new material.
Currently, the method that the resistant abrasion cavitation prevention performance of research concrete for hydraulic structure mainly uses comparative test, resistant abrasion examination
Such as most common underwater steel ball method, high speed water micromicrofarad are tested, anti-cavitation test such as scaling type cavitation corrosion generating device etc. passes through comparison
Test is it can be concluded that the opposite resistant abrasion of different materials or anti-cavitation corrosion intensity, to carry out evaluation and preferred to material.However,
Some method and apparatus are mostly considered by the test under single destruction, and in Practical Project, hydraulic structure wetted surfaces meeting
By the collective effect of sediment laden flow punching mill and cavitation corrosion, two kinds of destructions mutually promote, influence each other, complex, and non-one
As single destruction can characterize.In addition, if carrying out the cavitation test of silt carrying flow in laboratory, it will usually expect that muddy water tries
It tests, i.e., the grains of sand is mixed into reservoir, silt carrying flow is sent into test cycle system by water pump, and pilot system entire in this way has been filled with height
Fast silt carrying flow will cause very big damage to water pump, pipeline, measuring device etc., and silt content is also difficult to control, therefore the think of
Road is difficult the logical of row.Therefore, it is the resistant abrasion and cavitation prevention performance of energy scientific evaluation concrete for hydraulic structure, needs to research and propose one kind
New test method is capable of the immixture of real simulation punching mill and cavitation corrosion.
Summary of the invention
The object of the present invention is to provide the test methods that one kind can simulate high-velocity flow punching mill and cavitation corrosion immixture.
The technical solution that the present invention reaches above-mentioned purpose is:
Concrete for hydraulic structure punching mill and cavitation corrosion immixture test method, according to flow velocity more high pressure, lower hydraulics uncle exerts
Sharp principle increases sand supply automatically device on the basis of scaling type cavitation corrosion generator, the top and bottom of husky body in gaza's bucket
Pressure difference is formed, the sand supply automatically under the effect of high-pressure system internal pressure differences is realized, forms high speed sediment laden flow, carrying before aditus laryngis
When water flow to throat site, flow velocity reaches maximum value, negative pressure occurs, and strong cavitation occurs, and is fixed on the test specimen of diffuser after aditus laryngis
The double action with cavitation corrosion will be ground by sediment laden flow punching, sediment laden flow is separated water sand by settling pit after test section, water body
Reservoir circulation is flowed into, the grains of sand recycle and reuse.
Concrete for hydraulic structure punching mill with cavitation corrosion immixture test method, experimental rig include dynamical system, pressurizer tank, from
Dynamic gaza's device, test section and settling pit.Dynamical system uses three-phase motor driving multi-stage booster centrifugal pump for whole device confession
Water, water flow through water inlet piping and enter pressurizer tank, and pressurizer tank one terminates test section, and top is connected with gaza's bucket by communicating pipe, is added
Sand Bucket connects with the contraction section before test section aditus laryngis, and test section is followed by settling pit, and last water flow return water library forms circulation, specifically sets
Meter requires as follows:
(1) dynamical system uses three-phase motor driving multi-stage booster centrifugal pump for whole device water supply, motor rated power
120kW or more, working head 200m or more, the metered flow 60L/s or more of multi-stage booster centrifugal pump;
(2) sand supply automatically device is mainly made of Sand Bucket, cover board, exhaust pipe, observation window, sandline and control valve, husky
Bucket top is connected with pressurizer tank, and sandline is connected with the contraction section before test section aditus laryngis, since pressurizer tank cross dimensions is larger, case
Interior flow rate of water flow is lower, and static pressure is larger, reaches test section to water flow, cross dimensions is reduced rapidly, and flow rate of water flow significantly increases, quiet
It presses and reduces, therefore, Sand Bucket top pressure will be significantly greater than sandline outlet pressure, and under the action of upper and lower pressure difference, the grains of sand are by certainly
In dynamic sucking water, sediment laden flow is formed;
(3) test section, including contraction section, test specimen slot and diffuser, test section front and back monitor system internal pressure using pressure gauge
Power, pressure is affected to cavitation corrosion state after aditus laryngis, therefore is adjusted using valve, and to reach strong cavitation corrosion state, test specimen is solid
Due in test specimen slot, surface will be rushed mill and cavitation corrosion immixture by the strong cavitation water flow of carrying;
(4) settling pit, uses larger cross dimensions to reduce cross-sectional flow, precipitates the grains of sand, enters reservoir to prevent the grains of sand,
The silt content of water flow can be measured, simultaneously so as to Control experiment operating condition.
Concrete for hydraulic structure punching mill and cavitation corrosion immixture test method, test procedure are as follows:
(1) it before test, opens gaza's bucket bung and test sand is added into bucket, and gaza is observed by side wall observation window
Amount uses metal gasket and bolt seal between bung and gaza's bucket, and the concrete sample after weighing initial mass is packed into examination
Part slot, is then sealed;
(2) device that turns on the power is system water supply, by the pressure gauge observing system pressure before and after test section, opens gaza
Gas in the exhaust pipe discharge system on bucket top, since pressurizer tank and test section cross-sectional flow difference are larger, gaza bucket top and sediment transport
There are biggish pressure differences for pipe end, open sediment transport tube control flap, the grains of sand can mix automatically water flow, shape under the action of pressure difference
At sediment laden flow, in test section throat site, flow section is minimum, and sediment laden flow flow velocity reaches maximum value, negative pressure occurs, sends out
Raw strong cavitation, the concrete sample for being fixed on diffuser after aditus laryngis will be rushed the immixture of mill with cavitation corrosion by sediment laden flow, adjust
Water stream speed to test requirements document is tested;
(3) after test reaches the defined time, the quality of punching mill and test specimen after cavitation corrosion immixture is weighed, according to quality
Difference, active area and action time calculate rate of deteriorating.
The present invention has the advantage that
(1) using the Pressure Distribution in device, sand supply automatically is realized under the action of pressure difference in high-pressure system, is formed
Sediment laden flow does not need extra power;
(2) present apparatus forms sediment laden flow before position occurs for punching mill cavitation corrosion, and the grains of sand precipitate rapidly later, effectively avoid
Abrasion to other positions of device.
Specific embodiment
The present invention is described in further detail with reference to the accompanying drawings and examples.
Concrete for hydraulic structure punching mill cavitation corrosion immixture test method, according to the lower hydraulics Bernoulli Jacob of flow velocity more high pressure
Principle increases sand supply automatically device on the basis of scaling type cavitation corrosion generator, the top and bottom shape of husky body in gaza's bucket
At pressure difference, realizes the sand supply automatically under the effect of high-pressure system internal pressure differences, form high speed sediment laden flow, carrying water before aditus laryngis
When flowing to throat site, flow velocity reaches maximum value, negative pressure occurs, and strong cavitation occurs, and is fixed on the test specimen general of diffuser after aditus laryngis
By the double action of sediment laden flow punching mill and cavitation corrosion, sediment laden flow is separated water sand by settling pit after test section, water body stream
Enter reservoir circulation, the grains of sand recycle and reuse.
Concrete for hydraulic structure punching mill cavitation corrosion immixture test method, uses multi-stage booster centrifugal pump to supply for entire experimental rig
Water, water flow enter pressurizer tank 1, and 1 tapered at one end of pressurizer tank is connected with test section 2, pass through communicating pipe 3 and gaza's bucket at the top of pressurizer tank
4 are connected, setting bung 5 at the top of gaza's bucket, use husky 6 in bucket for test, and observation window 7 is arranged in side wall, and bung top is arranged exhaust pipe 8 and uses
In the gas in discharge system, gaza's bucket is connected by sandline 9 with the contraction section before test section aditus laryngis 10, cloth among sandline
It sets valve 11 and controls gaza's amount, concrete sample 12 is fixed on diffuser after test section aditus laryngis, and test section is followed by tailwater control valve
Door 13, then water flow enters settling pit 14, and last water flow return water library forms circulation, and the monitoring of pressure gauge 15 system is used before and after test section
Pressure in uniting.
Before test, opens gaza's bucket bung and test sand is added into bucket, and gaza's amount, bucket are observed by side wall observation window
Metal gasket and bolt seal are used between lid and gaza's bucket, the concrete sample after weighing initial mass is packed into test specimen slot,
It is then sealed, the device that turns on the power is system water supply, by the pressure gauge observing system pressure before and after test section, opens and adds
Gas in the exhaust pipe discharge system on Sand Bucket top, due to pressurizer tank and test section cross-sectional flow difference it is larger, gaza bucket top and it is defeated
There are biggish pressure differences for sand tube end, open sediment transport tube control flap, and the grains of sand can mix automatically water flow under the action of pressure difference,
Sediment laden flow is formd, in test section throat site, flow section is minimum, and sediment laden flow flow velocity reaches maximum value, negative pressure occurs,
Strong cavitation occurs, the concrete sample for being fixed on diffuser after aditus laryngis will be by the double action of sediment laden flow cavitation corrosion and punching mill.
It adjusts water velocity to test requirements document to be tested, after test reaches the defined time, after weighing punching mill and cavitation corrosion collective effect
The quality of test specimen calculates rate of deteriorating according to of poor quality, active area and action time.