1 / 19

Rankine Cycles for Nuclear Power Plants

Rankine Cycles for Nuclear Power Plants. P M V Subbarao Professor Mechanical Engineering Department. Valuing the greenhouse gas emissions from A Rankine Cycle Systems ……. Life Cycle of Nuclear Fuel. Safe Disposal. Nuclear Fission & Chain Reaction. Quantity of Fuel.

alexknight
Download Presentation

Rankine Cycles for Nuclear Power Plants

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Rankine Cycles for Nuclear Power Plants P M V Subbarao Professor Mechanical Engineering Department Valuing the greenhouse gas emissions from A Rankine Cycle Systems ……

  2. Life Cycle of Nuclear Fuel Safe Disposal

  3. Nuclear Fission & Chain Reaction

  4. Quantity of Fuel • The heat value is the amount of heat released during its combustion. • It is a measure of a fuel's energy density (kJ/kg) • One uranium pellet the size of the tip of your little finger is equivalent to energy provided by: • 800 kg of coal, • 480 cubic meters natural gas, or • 570 litre of oil.

  5. The closed nuclear fuel cycle

  6. The fuel fabrication process

  7. Fuel Rod Cluster

  8. Comparison of Life-Cycle Emissions Tons of Carbon Dioxide Equivalent per Gigawatt-Hour

  9. Rankine Cycle with Boiling Water Reactor

  10. Cycle Layout for BWR Plant p=1.12MPa T=250C p=7.012MPa T=286C p=0.004246MPa T=30C p=0.004246MPa T=30C p=7.012MPa T=173C

  11. Boiling Water Reactors • The flow into the reactor from the two feedwater systems is at normal conditions about 1250 kg/s. • The pressure and temperature at this point are about 7.012MPa and 173C. • The feedwater flow mixes with the recirculation flow in the downcomer and continues to the lower plenum through the recirculation pumps. • The temperature of the water in the lower plenum is 273C. • There are 6 circulation pumps which circulate the flow in the reactor.

  12. Boiling Water Reactors • The water flows from the lower plenum through the reactor core where the water starts to boil at 286C. after about half a meter. • The steam is very moisty when it reaches the top of the core and less than 10 % of the mass flow remains after the steam and moisture separators in the top of the reactor the rest has been separated. • The separated water is then again mixed with the incoming feedwater in the downcomer. • The thermal capacity of the reactor core is 2540 MW at maximal reactor. 20m 6m

  13. Steam System

  14. Reheater system • About 23 kg/s of hot steam is taken from each of the two high pressure steam chests to the hot tube side of the reheaters. • The purpose of this system is to heat and dry the moist steam after the HPT which now contains about 14 % of moisture. • The lower part of the reheater is a moisture separator and the condensate from there is transported to the separator drainage tank. • The steam is almost completely dry after the moist separation and are ready to be reheated from 185C to 250 C by the hot steam from the high pressure steam chests.

  15. The High Pressure – Boiling Water Reactor HP-BWR • The High Pressure Boiling Water Reactor (HP-BWR) offers improved nuclear safety and less damage to the environment. • The HP-BWR is an environmentally friendly, effective alternative. • The use of the HP-BWR means improved cycle thermal efficiency up to about ~40% instead of about ~30%.

  16. Supercritical water cooled reactor

  17. Rankine cycle with Pressurized Heavy Water Reactor

  18. Pressurized Heavy Water Reactor • Fuel assemblies are placed horizontally in a tank called a calandria. • Heavy water coolant is pumped through tubes containing the fuel assemblies to pick up the heat generated from the nuclear reaction. • The coolant then moves to the steam generators to produce steam from ordinary water and back to the reactor. • Heavy water is a rare but natural form of water and is the most effective moderator used in nuclear reactors to maintain continuous fissioning. • Ordinary water is a combination of one oxygen and two hydrogen atoms (H2O).

  19. Pressurized Heavy Water Reactor • Heavy water is virtually identical, except each of the hydrogen atoms have an extra neutron. • This hydrogen isotope is called deuterium (D). Since heavy water (D2O) has almost all the extra neutrons it wants, it slows neutrons in the reactor without significantly absorbing them. • The advantage of heavy water is that is permits the use of unenriched uranium as fuel. • This means two less steps are required in the conversion process resulting in a more economical fuel source.

More Related