Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15D—FLUID DYNAMICS, i.e. METHODS OR MEANS FOR INFLUENCING THE FLOW OF GASES OR LIQUIDS
  • F15D1/00—Influencing flow of fluids
  • F15D1/0015—Whirl chambers, e.g. vortex valves
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15C—FLUID-CIRCUIT ELEMENTS PREDOMINANTLY USED FOR COMPUTING OR CONTROL PURPOSES
  • F15C1/00—Circuit elements having no moving parts
  • F15C1/16—Vortex devices, i.e. devices in which use is made of the pressure drop associated with vortex motion in a fluid

Definitions

• Swirl generation also occurs, for example, when water drains through the drain opening in a bathtub.
• a region of low pressure in particular negative pressure, forms around the main axis, in which steam flows under saturation pressure or steam or gas of low density, as a result of which the volume and mass flow of the fluid are reduced.
• a connection of the swirl generation element to the flow channel guarantees a deflection of the flow from a flow direction in a plane perpendicular to the main axis into a flow direction parallel to the axis of the flow channel.
• the axis of the flow channel and the The main axis of the device are preferably identical, at least largely parallel to one another.
• the inflow component preferably has an inflow opening that is spaced from the main axis. In this way, a tangential flow perpendicular to the main axis can be achieved with little pressure loss.
• the swirl generating element is preferably arranged in a container of the system at which the flow channel ends.
• the inflow opening in the container can be spaced substantially further from the main axis, which preferably coincides with the axis of the flow channel, than a wall of the flow channel.
• the distance between the inflow opening and possibly a swirl vane from the axis is preferably larger than the diameter of the flow channel.
• a diffuser in particular a radial diffuser, is preferably arranged between the swirl generating element and the cross-sectional constricting element, which causes an increase in the flow cross section of the device from the cross-sectional constricting element to the swirl generating element.
• the flow cross section of the swirl generating element is preferably larger than the cross section of the flow channel, so that during normal operation of the system, in particular a cooling system of a nuclear power plant, the additional flow pressure losses of the cross sectional constriction element and swirl generating element due to the additional pressure recovery in the Diffuser is at least compensated, ie the normal volume flow through the device is not changed.
• FIG. 1 shows a device in a system for guiding a pressurized fluid in one
• the device 1 has a swirl generating element 4 with swirl blades 10, which are arranged on a circle 11 in a plane perpendicular to a main axis 3a of the device 1.
• the wire production element 4 forms in the region of the inflow openings 15 a circular disk-shaped inflow component 14 extending substantially perpendicular to the main axis 3a.
• the radius of the circle 11 is more than twice as large as the radius of the circular pipeline 2a.
• a cross-sectional constriction element 5 in the form of a Venturi tube connects to the diffuser 7.
• the smallest inner diameter of the cross-sectional constriction element 5 is approximately 62.5% of the inner diameter of the pipeline 2a.
• the device 1 with the swirl generating element 4, the diffuser 7 and the cross-sectional constricting element 5 forms a structural unit which is introduced into the pipeline 2a from the inside of the reactor pressure vessel 6a, so that the swirl generating element 4 in the Reactor pressure vessel 6a remains and the cross-sectional constriction element 5 projects into the line end 9. Due to the arrangement of the swirl blades 10 shown in FIG.
• the device 1 calls no or only insignificant additional flow ⁇ resistance.
• the height of the swirl generating element 4 of approximately 30 mm and the radius of the circle 11 of approximately 600 mm are selected such that the outflow cross-sectional area of the device 1 is significantly larger than the inflow area given by the cross-sectional area of the pipeline 2a.
• the volume flow of the fluid is not impaired during normal operation of the boiling water nuclear reactor system.
• the narrowing of the cross section the pipe 2a through the cross-sectional constriction element 5 is approximately 39%. If additional flow pressure losses are permissible, this narrowest cross-section can be reduced even further, for example to 27% of the cross-sectional area of the pipeline 2a, if the additional pressure loss coefficient ⁇ additionally equals 1 or 19% of the cross-sectional area of the pipeline 2a if ⁇ additionally the same 3 is.
• the inflow opening 15 and the swirl blades 10 are arranged as far as possible from an axis 3 of the flow channel 2. It is spaced apart from the main axis 3a, which coincides with the axis 3 of the flow channel, by more than twice the radius of the pipeline 2a.
• a pressure recovery is disturbed by the swirl generating element 4, at most slightly.
• the fluid flowing into the reactor pressure vessel 6a leaves the swirl generating element 4 almost without swirl.
• the swirl generating element 4 contributes significantly to the reduction and limitation of the volume flow and the mass flow in the event of a line break in the pipeline 2a.
• the outflow cross-section of the fluid in the pipeline 2a which is already greatly reduced in any case by the cross-sectional constriction element 5, thus has a mass flow density that becomes ever lower towards the main axis 3.
• the outflowing volume flow or mass flow is thus further significantly reduced by the swirl generated in the swirl generating element 4 in addition to the reduction due to the narrowing of the cross section.
• This reduction or limitation of the volume flow as a result of an additional swirl also occurs, for example, when water flows out of a bath tub, this outflow being slower the stronger the vortex which is formed in the drain pipe.
• the inflow component 14 experiences significantly reduced static pressures only in the vicinity of the main axis 3a; the swirl destruction element 8, however, is designed for the full static differential pressure.
• the swirl destruction element 8 With the exception of the vortex core, a potential vortex which forms in the swirl generating element 4 and the swirl destruction element 8 represents a largely swirl-free flow. Friction effects occur practically only on the inner walls of the swirl generating element 4 and the swirl eliminating element 8 is however relatively low due to the relatively low flow velocity in the area of the inner walls.
• a calm flow zone is formed in the vicinity of the main axis 3a, which roughly corresponds to the "eye of a typhoon".
• the emerging volume flow is limited to approximately 120% of the normal volume flow.
• the volume flow in the event of a leak is limited by generating swirl in a plane perpendicular to the flow direction of the fluid in the flow channel.
• the emerging volume flow can be limited to approximately 150% of the normal operating volume flow with little pressure loss. This corresponds to a reduction to approximately 75% of the volume flow exiting without the device.
• the volume flow can be limited in the event of a rupture to below 50% of the normal operational volume flow.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Mechanical Engineering (AREA)
• Theoretical Computer Science (AREA)
• Structure Of Emergency Protection For Nuclear Reactors (AREA)
• Monitoring And Testing Of Nuclear Reactors (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

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Citations (5)

• 1995
  • 1995-12-21 WO PCT/DE1995/001834 patent/WO1996019674A1/de active IP Right Grant
  • 1995-12-21 EP EP95942032A patent/EP0799385B1/de not_active Expired - Lifetime
  • 1995-12-21 DE DE59502286T patent/DE59502286D1/de not_active Expired - Lifetime
• 1997
  • 1997-06-17 FI FI972577A patent/FI112274B/sv not_active IP Right Cessation

Patent Citations (5)

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