Classifications

• • G—PHYSICS
  • G05—CONTROLLING; REGULATING
  • G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
  • G05D16/00—Control of fluid pressure
  • G05D16/04—Control of fluid pressure without auxiliary power
  • G05D16/06—Control of fluid pressure without auxiliary power the sensing element being a flexible membrane, yielding to pressure, e.g. diaphragm, bellows, capsule
  • G05D16/0616—Control of fluid pressure without auxiliary power the sensing element being a flexible membrane, yielding to pressure, e.g. diaphragm, bellows, capsule the sensing element being a bellow
  • G05D16/0619—Control of fluid pressure without auxiliary power the sensing element being a flexible membrane, yielding to pressure, e.g. diaphragm, bellows, capsule the sensing element being a bellow acting directly on the obturator
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/2496—Self-proportioning or correlating systems
  • Y10T137/2514—Self-proportioning flow systems
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T137/00—Fluid handling
  • Y10T137/2496—Self-proportioning or correlating systems
  • Y10T137/2514—Self-proportioning flow systems
  • Y10T137/2521—Flow comparison or differential response

Definitions

• Passive device for balancing the pressure of first and second fluids and use
• the invention relates to a passive device for balancing the pressure of a first fluid in a first circuit or container and of a second fluid in a second circuit or container and the use of the device for balancing the pressure of two fluids d heat exchange.
• fluids for example gases
• heat exchangers are used, such as plate heat exchangers, which are intended to receive, as the first fluid.
• a gas such as helium ensuring the cooling of the nuclear reactor core and, as a second exchange fluid, a gas containing nitrogen, for example air, which is used to cause a gas turbine and to vaporize water and produce steam which is used in steam turbines.
• the primary helium and the secondary exchange gas are at pressures in the region of 60 bars and care must be taken during normal operation of the installation, there is no pressure difference greater than 5 bars on either side of the exchange walls separating the primary helium from the secondary exchange gas. Nor should pressure gradients over time of more than 5 bars in 60 seconds be accepted.
• the two exchange gases In steady state operation, the two exchange gases generally have pressures which are kept within limits such that the critical pressure difference on either side of the exchange walls is never reached. It is not the same in the case of transient regimes or a fortiori in the case of incidental or accidental operation.
• these exchangers In order to be able to use heat exchangers which require operation with a small pressure difference between the exchange fluids, such as plate exchangers, these exchangers having, on other planes, very great advantages, it appears desirable if not essential to provide pressure balancing means between the two primary and secondary gas circuits.
• Such balancing means must operate fully automatically and require no source of energy supply external to the circuit for which pressure balancing is carried out, to avoid any risk of interruption of operation which would be damaging for the heat exchanger. heat.
• US-4,543,977, FR-1,027,361 and US-4,770,094 are known to be valves making it possible to adjust, relative to one another, the pressures of two fluids in respective containers or circuits.
• These devices use movable pistons in valve chambers ensuring the opening or closing of fluid passages, possibly by means of valves fixed on the pistons.
• the fluid passages are sealed off by placing the pistons or valves integral with the pistons on the sealing surfaces of the valves.
• the fluids are separated by movable seals carried by the pistons.
• the object of the invention is to propose a device for balancing the pressure of a first and a second fluids contained, respectively, inside a first and a second circuit or receptacles, safe and automatic operation, without the need for an external energy source such as an electrical power supply and with perfect separation of fluids.
• the balancing device according to the invention comprises:
• a first and a second valve comprising, respectively, a first and a second valve body delimiting, respectively, a first and a second chamber, communicating by a first and a second inlet orifices with the first and with the second circuits or receptacles containing, respectively, the first and the second fluids and through an exhaust orifice with a respective exhaust means of the first and of the second fluids, at least a first valve and at least a second valve mounted movable respectively in the first and in the second chamber in an axial actuation direction, between a closed position and an open position of the exhaust port of the first and second chambers, respectively, a first and a second piston constituted each by a rigid plate integral respectively with the first and the second valve and a flexible metal wall with a bellows tightly fixed to the plate e of the respective piston and an element of the first and second valve bodies, respectively, so as to constitute a closed chamber having a wall which is deformable in the direction of actuation and first and second return means elastic of
• the body of the first valve and the body of the second valve are connected together and axially aligned in a common actuation direction of the first and the second valves to form a body of the balancing device, the chamber of the first valve and the chamber of the second valve being separated by a wall transverse to the direction of actuation of the body of the balancing device to which is fixed, on a first side inside the chamber of the first valve, the metal wall of the bellows of the first piston and, on a second side in the direction of actuation, inside the chamber of the second valve, the metal wall of the bellows of the second piston, the partition wall of the body of the balancing device being traversed by a first channel for communicating the first closed chamber of the first piston with the chamber of the second valve and by a second c anal putting the closed chamber of the second piston into communication with the chamber of the first valve;
• the body of the first valve and the body of the second valve are made in two parts assembled together delimiting respectively a first part of the valve chamber in which the intake opening and the exhaust opening are provided. and a second part in which the first and second pistons are disposed, respectively, the first and second parts of the chambers of the first and second valves being separated by a wall of the body of the valve traversed by an opening in the direction axial actuation in which is disposed a bearing for guiding the corresponding valve which comprises a rod mounted in the axial direction of actuation, one of which axial end is integral with the corresponding piston and the opposite end of which, inside the first part of the valve chamber carries a shutter;
• the first valve of the first valve and the second valve of the second valve each comprise a shutter assembly of the exhaust opening comprising a pilot valve shutter secured to one end of a valve stem and a main shutter comprising a bearing surface on a seat of the exhaust opening and a central cavity in which is engaged, with a latitude of displacement in the direction of the actuation axis of the valve, the pilot valve shutter, communicating with the outside of the main valve by a channel whose pilot valve shutter is capable of closing;
• the first and second elastic return means of the first and second valves are constituted by helical springs interposed between a bearing surface of the valve and one of a piston to which the valve is connected and a surface d support of a body of the corresponding valve of the balancing device;
• the helical spring is supported at at least one of its ends on a support plate whose position is adjustable in the direction of actuation of the valves of the balancing device.
• the device according to the invention can be used to adjust, to substantially equal values, the pressure of two fluids in supply circuits of a first heat exchange part and a second heat exchange part, respectively, a heat exchanger.
• the first heat exchanger circuit may be intended to receive a secondary heat exchange gas containing nitrogen from an electricity production installation using a high temperature nuclear reactor and the second circuit d exchange is the primary circuit of the high temperature nuclear reactor cooled by a gas such as helium.
• the single figure is a view in axial section of a balancing device according to the invention and of two exchange circuits in which pressure balancing is carried out.
• the balancing device generally designated by the reference 1 comprises a body 12 of generally hollow cylindrical shape delimiting internal chambers 13a and 13b which are the respective chambers of a first regulating valve 35a for the pressure of a first fluid and a second valve 35b for adjusting the pressure of a second fluid.
• the first fluid can be a nitrogen-containing gas and the second fluid is helium cooling from a high temperature nuclear reactor.
• the first fluid which is for example air is in circulation in a first circuit 36a connected to a first intake opening of the first fluid and the second fluid which is for example helium cooling from a nuclear reactor to high temperature circulates in a second circuit 36b connected to a second intake opening of the balancing device 1.
• the air circuits 36a and helium 36b are connected to a heat exchanger 37 ensuring the heating of the air from the helium taking the heat from the heart of the nuclear reactor.
• the body 12 of the balancing device 1 is produced in several parts 12a, 12b, 12c, 12d and 12e which are joined together end to end in the direction of the actuating axis 15 of the balancing device, by l '' through flanges, screws or threaded rods and nuts, with interposition of seals such as 16a, 16b, 16c and 16d.
• the realization of the body 12 of the balancing device from parts which can be assembled makes it possible to simplify the manufacture and to carry out the mounting of the internal organs of the valves.
• the two parts of the chambers 13a and 13b are interconnected by a channel 17a (or 17b) allowing the two parts of the chamber to be put under pressure.
• the first parts 13'a (or 13'b) of the chambers 13a (or 13b) which are produced inside the part 12a (or 12b) of the body of the device each have an intake opening 19a (or 19b) and an exhaust opening 18a (or 18b), the exhaust opening being fitted with a valve seat for pressing the shutter of the corresponding valve flap.
• the intake opening 19a of the first chamber 13a is connected to a line connecting to the circuit 36a in which the first fluid circulates and the exhaust opening 18a to an exhaust line of the first fluid (for example from the 'air).
• the intake opening 19b of the second chamber 13b is connected by a connecting line to the second fluid circuit 36b (for example helium cooling the nuclear reactor at high temperature) and the exhaust opening 18b is connected to a helium evacuation pipe to a storage tank 39.
• the two respective adjustment valves for the pressure of the first and second exchange gas are produced in the same way, so that only the first valve disposed in the chamber 13a will be described in detail, while indicating the differences that exist. with the second valve as for the pressure connections of the valves.
• the valve arranged in the chamber 13a ensuring the adjustment of the pressure of the first fluid constituted by a gas containing nitrogen comprises a valve 20a comprising a rod mounted to slide in the axial actuation direction 15 inside the bearing 14a of the valve and connected, at a first end, to a shutter assembly 21a and, at a second end, to a piston 22a, 24a disposed inside the part 13 "a of the chamber 13a.
• the piston 22a, 24a comprises a rigid plate 22a secured to the flexible wall of a metal bellows 24a which has at least one toric wave having as its axis the axis 15 of actuation of the balancing device.
• the flexible wall of the bellows 24a is also fixed by welding to a fixing plate 25a secured to the intermediate piece 12e of the body 12 of the balancing device which separates the chamber 13a of the first valve from the chamber 13b of the second valve.
• a bellows can be used
• the deformable metal wall of the bellows 24a is solid, at its axial end opposite to the plate 25a, of a fixing ring 26a in which one comes to fix by welding, at the time of assembly, a plate 22'a in the form of a disc secured to the stem of the valve 20a guided in the bearing 14a, to form the rigid plate 22a of the piston 22a, 24a.
• the piston 22a, 24a thus has an internal chamber which is completely closed, at its periphery, by the metal bellows 24a, at one of its axial ends, by the plate 25a and, at its second axial end, by the plate 22a of the piston.
• the external surface of the piston subjected to pressure in the valve chamber constitutes its external face and the internal surface of the closed chamber its internal surface.
• a channel 27a pierced inside the intermediate piece 12e of the body of the balancing device passing through the fixing plate 25a places the internal chamber of the piston 22a, 24a in communication with the second part 13 "b of the chamber 13b of the second valve.
• a channel 27b passing through the intermediate piece 12e of the body 12 of the balancing device and a fixing plate 25b of the bellows 24b of the second valve places the internal chamber of the piston 22b, 24b of the second valve 35b in communication with the second part 13 "a of chamber 13a of the first valve.
• the shutter assembly 21a connected to the end of the valve stem 20a comprises a pilot valve shutter 21 'a of small diameter and a main valve shutter 21 "a with large diameter intended to come into abutment by a tapered surface covered by a layer of wear material, with the seat of the exhaust opening 18a, in a closed position valve 35a.
• the shutter 21 'a of the pilot valve is engaged with a certain clearance in the axial direction 15 in an opening inside the shutter 21 "a of the main valve which communicates with an outlet channel 31a of small diameter emerging in the exhaust opening 18a on which the shutter 21'a of the pilot valve is in abutment in the closed position of the valve.
• the shutter 21 "a of the main valve further comprises through lateral channels placing its central opening in communication, in which the shutter 21 'a of the pilot valve is arranged with the first part 13'a of the chamber 13a of the valve.
• a helical return spring 32a is interposed between a bearing portion of the bearing 14a for guiding the valve stem 20a secured to the body 12 and a support flange 33a engaged on the valve stem, so as to recall the shutters 21 'a and 21 "a in the closed position, respectively, of the seat 18a and of the channel 31a.
• This second valve comprises elements similar to the elements which have been described in the case of the first valve which are given the same references but with the letter b as an index.
• the helical return springs 32a and 32b come to bear on a flange 33a (or 33b) which is crossed by an opening for passage of the stem of the corresponding valve 20a (or 20b) which has a thread on its external surface.
• An adjustment nut 34a (or 34b) is engaged on the threaded part of the valve stem and comes to bear on the corresponding support flange 33a (or 33b), so as to adjust the setting of the corresponding spring 32a and 32b. It is thus possible to adjust the trigger pressure of the pilot valve of the valve which is returned to its seat by the return spring 32a (or 32b).
• the spring which is interposed between the piston and the shutter of the valve 20a (or 20b) can be associated with calibration means constituted by at least one end support flange spring which can be moved in the direction of the axis actuation 5, for example by a nut or other mechanical, pneumatic or hydraulic displacement means.
• At least one of the ends of the spring can be supported on an adjustable support plate to adjust the calibration of the spring, both in the case of the first and of the second embodiments.
• the first parts 13'a and 13'b of the chambers 13a and 13b of the two valves receive, respectively, during the operation of the installation, the first fluid and the second fluid coming from the first and from the second circuits of the installation, respectively 36a and 36b.
• the two valves When the pressures in the two circuits are equal or practically equal, the two valves are in their position shown in FIG. 2, the valves 21'a, 21 'b, 21 "a and 21" b being kept in the closed position on the corresponding seats of the exhaust openings and the main shutter channels.
• the chambers of the pistons delimited by the metal bellows and the rigid plates integral with the valves of the two valves 35a, 35b are subjected on their external surface, respectively, to the pressure of the first and of the second fluids and, on their internal surface, to the pressure of the second and first fluids.
• the chambers of the pistons delimited by the deformable walls of the bellows 24a and 24b and the external and internal faces of the pistons are subjected to a pressure internal and external pressure which are different from each other.
• the chamber of the first piston delimited by the first bellows 24a is under internal pressure which is the pressure of the second fluid transmitted through the channel 27a less than the pressure to which its external wall is subjected inside the second part 13 "a of the chamber 13a which receives the first fluid.
• the plate 22a of the first piston 22a, 24a tends to move downwards (in FIG. 2) in the actuating direction 15 of the balancing device.
• valve 20a moves downwards, so that the shutter 21 'of the pilot valve ensures the opening of the channel 31a and the discharge of first fluid to the exhaust pipe.
• the shutter 21 "a constituting the main valve remains in the closed position against the seat of the exhaust opening 18a. If the pressure difference between the two fluids continues to increase, the valve 20a moving downwards can ensure the opening of the shutter 21 "a of the main valve, so that the escape of the second fluid through the opening exhaust 18a occurs at a flow rate much higher than the flow rate provided by the passage through the channel 31a.
• the pressure in the first circuit drops, moderately during the opening of the pilot valve and then much faster, during the opening of the main valve.
• the pressure in the closed chamber of the second piston delimited by the second bellows 24b is greater than the pressure in the second part 13 "b of the valve chamber, as long as the pressure of the first fluid is greater than the pressure of the second fluid.
• the overpressure inside the closed chamber of the second piston ensures closing of the second valve 20b with increasing force, when the pressure difference between the first and the second fluids increases.
• the closing of the second valve is ensured by means of of the second return spring 32b, by compression of this spring.
• the balancing device therefore makes it possible to maintain the first and the second circuits, practically in equilibrium, which makes it possible to avoid any difference in pressure damaging to the heat exchanger, on either side of its exchange surfaces.
• the pilot valves remain in place on their seats and the installation continues to operate in slightly degraded conditions.
• one of the two pilot valves opens to restore the pressure on the two circuits.
• the balancing device according to the invention therefore makes it possible to limit the pressure differences in operation between the two circuits as much as possible.
• the device operates completely automatically and completely independently of any energy source (for example electric or hydraulic) external to the installation itself in which the device provides pressure balancing.
• first and second fluids are completely separated from each other, the chambers delimited by the bellows and the plates of the pistons of the balancing device being completely closed and perfectly sealed.
• the assembly constituted by the piston and the deformable bellows chamber makes it possible to transmit very high forces for the opening of the valves against the return springs of these valves.
• the installation can therefore be carried out in a form ensuring perfect sealing of the valves, in the normal operating phases in steady state.
• the balancing device according to the invention allows operation with high temperature fluids, such as for example exchange fluids from an installation comprising a high temperature nuclear reactor.
• the bellows of the chambers of the pistons of the balancing device are also produced so as to be able to withstand a pressure corresponding to the pressure in the circuits in which the pressure balancing is carried out, for example 60 bars in the case of application. considered above.
• the invention is not strictly limited to the embodiment which has been described.
• the device for calibrating the springs for adjusting the width of the dead band for operating the adjustment can be achieved by any mechanical means, for example with screw and nut or with toothed wheel and worm or even by any pneumatic or hydraulic means.
• the calibration of the spring of the first valve and the calibration of the spring of the second valve can be carried out at different values, for example to ensure finer pressure monitoring, in one of the two circuits. It is also possible to use balancing devices according to the invention to achieve pressure balancing between circuits, installations or containers in a greater number than two.
• first, a second and a third circuit containing, respectively, a first, a second and a third fluid
• a first balancing device and a pressure balancing between for example the second and the third circuits by a second balancing device.
• Pressure balancing is thus obtained between the three circuits which can be maintained, for example, in equipression by using two similar balancing devices.
• the invention is not limited either to the application which has been described above, that is to say the pressure balancing between two circuits of a heat exchanger, in an installation for producing electrical energy only from the heat produced by a high temperature nuclear reactor.
• the balancing device according to the invention can be used for example to achieve pressure balancing in low pressure bodies of steam turbines.
• a balancing device can also be used to balance in pressure two containers containing fluids whose mixing is to be avoided.
• the balancing device comprises valves whose chambers are closed by bellows, for example as described with reference to FIG. 2, the bellows can comprise any number of waves and not only a single wave of toroidal form, as described above.
• the bellows can be made of any metallic or non-metallic material, the characteristics of which can be defined as a function of the desired elasticity and of the resistance to the fluid with which the bellows comes into contact, as a function of the pressure and temperature conditions of this fluid.
• a shutter assembly can be used such as the assembly 21a comprising a pilot valve shutter and a main shutter, both in the case of the first and of the second embodiments.
• the two valves comprise a common body which constitutes the body of the balancing device produced in several parts to allow the mounting of the elements of the valves.
• the two valve bodies independently and to place these valve bodies in any relative arrangements, for example in areas remote from one of the 'other and arranged near each of the circuits or containers in which a pressure balancing is carried out.
• the device according to the invention can be used both for balancing the pressure of gases, as has just been described, and of liquids or of gases and liquids.

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• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• General Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Automation & Control Theory (AREA)
• Fluid-Driven Valves (AREA)
• Control Of Fluid Pressure (AREA)
• Jet Pumps And Other Pumps (AREA)
• Multiple-Way Valves (AREA)

Applications Claiming Priority (3)

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Family Cites Families (13)

• 2002
  • 2002-10-30 FR FR0213620A patent/FR2846757B1/fr not_active Expired - Fee Related
• 2003
  • 2003-10-28 EP EP03780240A patent/EP1570327A1/fr not_active Withdrawn
  • 2003-10-28 JP JP2004551085A patent/JP2006505073A/ja active Pending
  • 2003-10-28 WO PCT/FR2003/003212 patent/WO2004044668A1/fr not_active Application Discontinuation
  • 2003-10-28 CN CNB2003801046708A patent/CN100541378C/zh not_active Expired - Fee Related
  • 2003-10-28 US US10/533,065 patent/US7377288B2/en not_active Expired - Fee Related
  • 2003-10-28 AU AU2003288336A patent/AU2003288336A1/en not_active Abandoned
• 2005
  • 2005-04-22 ZA ZA200503280A patent/ZA200503280B/xx unknown

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