A Carbon Dioxide Partial Condensation Cycle for High Temperature - PowerPoint PPT Presentation

2 nd Information Exchange meeting on Basic Studies in the Field of High Temperature Engineering A Carbon Dioxide Partial Condensation Cycle for High Temperature Reactors Oct. 10th,2001 Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology ○ Takeshi Nitawaki Yasuyoshi Kato Yoshio Yoshizawa 1

1. TITAN Project B a c k g r o u n d I n t e r e s t i n s m a l l a n d m e d i u m s i z e r e a c t o r s i s s t e a d i l y i n c r e a s i n g i n t h e w o r l d f o r e l e c t r i c i t y g e n e r a t i o n a s w e l l a s f o r d i s t r i c t h e a t i n g i n c i t i e s a n d i s l a n d . T I T A NP r o j e c t - T o k y o I n s t i t u t e o f T e c h n o l o g y A d v a n c e d N u c l e a r E n e r g y - S t a r t i n D e c e m b e r 1 9 9 9 D e v e l o p m e n t o f A d v a n c e d S m a l l a n d M e d i u m S i z e R e a c t o r - C O 2 d i r e c t c y c l e f a s t r e a c t o r s - C O 2 d i r e c t c y c l e t h e r m a l r e a c t o r s - S i m p l e s a f e b o i l i n g w a t e r r e a c t o r s 2

2. CO 2 as Coolant <Major advantages of CO 2 > (1)Small burnup reactivity swing & control requirements, efficient burning of MA (due to harder neutron spectrum) (2)Higher heat transport ability than He (due to its thermodynamic properties) (3)Ease in inspection & maintenance (due to Transparency) (4) Simple system and high efficiency with direct cycle (due to condensability) 3

3. Real Gas Behavior in CO ２ Compression The work W in the isentropic expansion and compression processes of one mol real gas is given by ∫ ∫ = − = − W V dP zRT dP P V ： 、 ： 、 ： 、 Volume P Pressure R Gas Constant ： 、 ： T Temperatur e z Compressib ility Factor = z f(Tr,Pr) = Tr (Reduced Temperatur e) T/Tc, Tc : Critical Temperatur e = Pr (Reduced Pressure) T/Tc, Pc : Critical Pressure Gases with a same z value take a same behavior according to the “ law of corresponding states ” . (z=1:ideal gas) At the critical temperature and pressure, the z value dips sharply below the ideal line of unity and takes an extremely low value as low as about 0.2. A low z value indicates the real gas is more compressible than the ideal gas. 4

4(1) Compressibility Factor 1 . 2 1 . 6 1 . 6 3 1 . 4 2 ｚ 4 R e d u c e d T e m p e r a t u r e Ｔ ｒ = 1 . 0 1 . 1 1 . 4 6 8 1 0 1 . 2 r C O C o m p r e s s i o n 1 5 2 o t c 1 . 0 a F 2 H e C o m p r e s s i o n y 0 . 8 1 . 6 t i l 1 . 4 i b i 0 . 6 s s 1 . 2 e r 0 . 4 p 1 . 1 D r a w n f r o m t h e d a t a i n m o 0 . 2 O . A . H o u g e n , e t a l . , " C h e m i c a l P r o c e s s P r i n c i p l e s , C 1 . 0 P a r t Ⅱ, T h e r m o d y n a m i c s " , J o h n W i l e y & S o n s ( 1 9 6 0 ) 0 . 0 0 2 4 6 8 1 0 1 2 1 4 1 6 1 8 2 0 2 2 2 4 R e d u c e d P r e s s u r e Ｐ ｒ 5

4(2) Critical Parameters & Compressibility Factor T y p i c a l T y p i c a l C r i t i c a l C o m p r e s s i o n E x p a n s i o n P a r a m e t e r s ( 3 5 ℃ 、5 M P a ) G a s （ 6 5 0 ℃ 、1 2 . 5 M P a ) T c P c T ｒ P ｒ z T ｒ P ｒ z ( K ) ( M P a ) Ｈ ｅ 5 . 1 9 5 0 . 2 7 5 5 9 . 3 1 1 8 . 1 8 ～1 1 7 7 . 7 0 5 4 . 9 5 ～1 Ｃ Ｏ 3 0 4 . 1 4 7 . 3 8 4 1 . 0 1 0 . 6 8 ～0 . 7 3 . 0 3 1 . 6 9 ～1 ２ T ｒ ： R e d u c e d T e m p e r a t u r e （＝ T ／T ｃ 、 T ｃ ： C r i t i c a l T e m p e r a t u r e ） 、 P ｒ ： R e d u c e d P r e s s u r e （＝ P ／P ｃ 、 P ｃ ： C r i t i c a l P r e s s u r e ） 、 ｚ ： C o m p r e s s i b i l i t y F a c t o r The compression work of CO near the critical point 2 （ 31 ℃、7.4MPa ） is smaller than that of He. 6

5. CO Direct Cycle ２ (1) Carbon dioxide - Condensable from gas to liquid phase - Critical temperature = 31 ℃ (304K) (2)Variation of CO ２ Cycle ① Full Condensation Cycle ② Partial Condensation Cycle ③ Non - Condensation Cycle （Brayton Cycle ） 7

6(1) CO ２ Cycle －Full Condensation － ④ Turbine Turbine ④ Work Generator Reactor Power Temperature ⑤ ⑤ Reactor ③ Cooling ⑥ Water Pump Recuperation ③ Heat Pump ② ① ② Work ⑥ Recuperator Condenser ① Condenser Rejection Heat Liquid CO 2 Storage Tank Entropy (a) Coolant flow circuit (b)T-S diagram 8

6(2) CO ２ Cycle －Non Condensation － ④ R e a c t o r C o m p r e s s o r Ⅱ G e n e r a t o r T u r b i n e ④ C o m p r e s s o r Ⅰ W o r k R e a c t o r r P o w e r ⑧ e e l ⑤ r o ① T u r b i n e u ⑤ o t C a ③ ⑦ - r r ③ e e t r n p e I l o m o R e c u p e r a t i o n e C T H e a t - e ② r ② C o m p r e s s o r P ⑥ ⑥ W o r k ⑧ P r e - C o o l e r R e c u p e r a t o r ① ⑦ R e j e c t i o n H e a t I n t e r - C o o l e r L i q u i d C O S t o r a g e T a n k R e j e c t i o n H e a t 2 E n t r o p y (a) Coolant flow circuit (b) T-S diagram 9

6(3) CO ２ Cycle －Partial Condensation － ⑤ C o m p r e s s o r Ⅱ R e a c t o r ⑤ G e n e r a t o r T u r b i n e C o m p r e s s o r Ⅰ W o r k R e a c t o r ⑪ P o w e r ⑥ ⑩ e T u r b i n e ⑥ r C o n d e n s e r u ⑨ ④ t r ④ e a l r o e o ① p ③ C P u m p - m R e c u p e r a t i o n e r e ② H e a t ⑪ P T ③ ⑦ C o m p r e s s o r ⑦ ⑧ W o r k ② ⑧ P u m p ⑩ R e c u p e r a t o r Ⅱ W o r k P r e - C o o l e r ⑨ ① R e j e c t i o n H e a t R e c u p e r a t o r Ⅰ C o n d e n s e r L i q u i d C O S t o r a g e T a n k R e j e c t i o n H e a t 2 E n t r o p y (a) Coolant flow circuit (b) T-S diagram 10

7. Comparison of Cycle Efficiency 6 0 R e a c t o r O u t l e t P r e s s u r e P a r a m e t e r s F u l l C o n d . N o n - C o n d . P a r t i a l C o n d . ： ２ ０ ． ０ Ｍ Ｐ ａ ： １ ７ ． ５ Ｍ Ｐ ａ 5 5 P r e - C o o l e r － ３ ５ ３ ５ ： １ ５ ． ０ Ｍ Ｐ ａ T e m p . ( ℃ ） ： １ ２ ． ５ Ｍ Ｐ ａ I n t e r - C o o l e r － ３ ５ － ： １ ０ ． ０ Ｍ Ｐ ａ T e m p . ( ℃ ） 5 0 ： ７ ． ５ Ｍ Ｐ ａ ％） C o m p r e s s o r N o n - P r e s s u r e － S a m e f o r T w o － P r o p o s e d T h e r m a l R a t i o （ . Ｍ Ｐ ａ ） C o n d . （ R e a c t o r 4 5 C o n d e n s e r ２ ５ － ２ ５ y T e m p . ( ℃ ） c ＰＢＭＲ P r o p o s e d F a s t n T u r b i n e ９ ０ ９ ０ ９ ０ e R e a c t o r E f f i c i e n c y （ ％ ） i ＡＧＲ 4 0 c i C o m p r e s s o r f － ９ ０ ９ ０ f P a r t i a l C o n d . F B R E f f i c i e n c y （ ％ ） E P u m p e ９ ０ － ９ ０ ＡＰＷＲ 3 5 l E f f i c i e n c y （ ％ ） c y E x p a n s i o n F i x e d O u t l e t f o r M a x . ＡＢＷＲ f i x e d t o ３ ． ５ C R a t i o （ － ） P r e s s u r e e f f i c i e n c y 3 0 Ⅰ ： ９ ０ Ⅱ ：C a l c u l a t e d F u l l C o n d . R e c u p e r a t o r s o a s t o E f f e c t i v e n e s s ９ ０ ９ ０ k e e p L M T D （ ％ ） o f R e c u p . Ⅱ 2 5 o f ３ ０ ℃ 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0 R e a c t o r O u t l e t T e m p . （ ℃） 11