摘要:
A feedring for use with an axial flow preheat steam generator which utilizes a double wrapper to direct feedwater flow to the cold leg tube bundle region. The feedring is positioned directly over the double wrapper and includes a plurality of standpipes spaced circumferentially along the feedring. The standpipes respectively extend vertically from a lower portion of an interior of the feedring upward through the interior of the feedring. The standpipes have a feedwater intake in the upper portion of the feedring to minimize the potential for vapor formation and bubble collapse water hammer. The components of the standpipe are arranged to minimize the transmission of entrained loose parts from traveling with the feedwater to the tube bundle. A feedwater discharge is provided at the exit of the standpipe at or below the bottom of the feedring, for evenly distributing the feedwater into the double wrapper downcomer.
摘要:
A feedring for use with an axial flow preheat steam generator which utilizes a double wrapper to direct feedwater flow to the cold leg tube bundle region. The feedring is positioned directly over the double wrapper and includes a plurality of standpipes spaced circumferentially along the feedring. The standpipes respectively extend vertically from a lower portion of an interior of the feedring upward through the interior of the feedring. The standpipes have a feedwater intake in the upper portion of the feedring to minimize the potential for vapor formation and bubble collapse water hammer. The components of the standpipe are arranged to minimize the transmission of entrained loose parts from traveling with the feedwater to the tube bundle. A feedwater discharge is provided at the exit of the standpipe at or below the bottom of the feedring, for evenly distributing the feedwater into the double wrapper downcomer.
摘要:
A method and apparatus are disclosed for substantially eliminating flow induced vibrations of the flow tubes of a steam generator in the U-bend region. Antivibration bars are provided between columns of flow tubes in the U-bend region which are contoured on one side to correspond with the exact as-built and as-bent diameter of the tubes as located within the tube bundle. Measurements of the actual flow tube diameters are made and recorded and stored either on tape or in a computer which is then used to control a numerically operated machine which configures or machines cutouts in the antivibration bars to precisely correspond with the respective measured diameters of the flow tubes. Only one side of the antivibration bars need to be machined because of the flexibility of the flow tubes which allow the positioning of the other side of the flow tubes along a flat plane.
摘要:
A thermal sleeve is mechanically attached to the bore of a surge nozzle of a pressurizer for the primary circuit of a pressurized water reactor steam generating system. The thermal sleeve is attached with a series of keys and slots which maintain the thermal sleeve centered in the nozzle while permitting thermal growth and restricting flow between the sleeve and the interior wall of the nozzle.
摘要:
A tube and shell steam generator having an anti-clogging heat exchange tube bundle wherein the tube support plates within the tube bundle are designed with varying degrees of porosity thereby regulating local secondary side fluid conditions (velocity, quality, superheat, void fraction, etc.) in a manner to reduce the potential for clogging of the tube support plate lobes that are more prone to clogging.
摘要:
A thermal sleeve is mechanically attached to the bore of a surge nozzle of a pressurizer for the primary circuit of a pressurized water reactor steam generating system. The thermal sleeve is attached with a series of keys and slots which maintain the thermal sleeve centered in the nozzle while permitting thermal growth and restricting flow between the sleeve and the interior wall of the nozzle.
摘要:
A stayrod configuration for permitting complete sludge lancing of the tubesheet, including a plurality of first stayrods, each having the same diameter as the steam generator tubing and being threaded into the tubesheet at spaced positions which match the tube pattern. This plurality of first stayrods is attached to a connector, which is threaded to provide a receptacle for a second, full-length stayrod within a shortened spacer.
摘要:
A tube support plate is disclosed for supporting a plurality of tubes with reduced vibration in a nuclear steam generator. The support plate has a plurality of holes disposed therethrough in a regular array. Each hole has an axis, an interior surface and a plurality of lands supported on the interior surface and extending towards the axis. The support plate has a given thickness as taken along the hole axis, and each of the lands has a tapered surface for facilitating tube insertion. The method of forming the tube support plate comprises a first step of forming each of the holes through the support plate with a first cylindrical portion of a first diameter and a second cylindrical portion of a second diameter less than the first diameter. Next, portions of the second cylindrical portion are removed in a second step to form a plurality of lands having exposed ends supporting a tube within the hole.
摘要:
A means of offsetting semi-circular tube support plates typically present in heat exchangers with cross flow baffles, such as axial flow economizers, utilizing the motive force of steam generator pressurization. The offset slightly flexes the tubes, thereby providing a preload which minimizes the potential for tube vibration and wear.
摘要:
A tube and shell steam generator in which a series of rods having a diameter substantially equal to that of the heat exchange tubing in the tube bundle are placed on either side of the tube lane to buffer the flow in the tube lane from the heat exchange tubes to attenuate turbulent forces on the first several rows of heat exchange tubes adjacent to the tube lane.