ICONE DESIGN AND TEST PLAN OF THE SUPERCRITICAL CO 2 COMPRESSOR TEST LOOP

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roceedings of the 16th International Conference on Nuclear Engineering ICONE16 May 11-15, 008, Orlando, Florida, USA ICONE16-48335 DESIGN AND ES LAN OF HE SUERCRIICAL CO COMRESSOR ES LOO akao Ishizuka Yasushi Muto Masanori Aritomi Research Laboratory for Research Laboratory for Research Laboratory for Nuclear Reactors Nuclear Reactors Nuclear Reactors okyo Institute of echnology okyo Institute of echnology okyo Institute of echnology -1-1 O-okayama, Meguro-ku, -1-1 O-okayama, Meguro-ku, -1-1 O-okayama, Meguro-ku, okyo, 15-8550 Japan okyo, 15-8550 Japan okyo, 15-8550 Japan hone: +81-3-5734-3849 hone: +81-3-5734-3849 hone: +81-3-5734-3063 Fax: +81-3-5734-959 Fax: +81-3-5734-959 Fax: +81-3-5734-959 e-mail: takao.i@nr.titech.ac.jp e-mail: muto@nr.titech.ac.jp e-mail: maritomi@nr.titech.ac.jp ABSRAC Supercritical carbon dioxide (CO ) gas turbine systems can generate power at a high cycle thermal efficiency, even at modest temperatures of 500 550 C. hat high thermal efficiency is attributed to a markedly reduced compressor work in the vicinity of critical point. In addition, the reaction between sodium (Na) and CO is milder than that between H O and Na. Consequently, a more reliable and economically advantageous power generation system can be created by coupling with a Na-cooled fast breeder reactor. In a supercritical CO turbine system, a partial cooling cycle is employed to compensate a difference in heat capacity for the high-temperature low-pressure side and low-temperature high-pressure side of the recuperators to achieve high cycle thermal efficiency. In our previous work, a conceptual design of the system was produced for conditions of reactor thermal power of 600 MW, turbine inlet condition of 0 Ma/57 C, recuperators 1 and effectiveness of 98%/95%, Intermediate Heat Exchanger (IHX) pressure loss of 8.65%, a turbine adiabatic efficiency of 93%, and a compressor adiabatic efficiency of 88%. Results revealed that high cycle thermal efficiency of 43% can be achieved. In this cycle, three different compressors, i.e., a low-pressure compressor, a high-pressure compressor, and a bypass compressor are included. In the compressor regime, the values of properties such as specific heat and density vary sharply and nonlinearly, dependent upon the pressure and temperature. herefore, the influences of such property changes on compressor design should be clarified. o obtain experimental data for the compressor performance in the field near the critical point, a supercritical CO compressor test project was started at the okyo Institute of echnology on June 007 with funding from MEX, Japan. In this project, a small centrifugal CO compressor will be fabricated and tested. During fiscal year (FY) 007, test loop components will be fabricated. During FY 008, the test compressor will be fabricated and installed into the test loop. In FY 009, tests will be conducted. his paper introduces the concept of a test loop and component designs for the cooler, heater, and control valves. A computer simulation program of static operation was developed based on detailed designs of components and a preliminary design of the compressor. he test operation regime is drawn for the test parameters. 1 INRODUCION Nuclear generation systems combining a sodium-cooled fast reactor with a super-critical carbon dioxide gas turbine system have been proposed (Dostal, V., 00; Kato, Y., 005; Kato, Y., 007; Muto, Y., 006; Muto, Y., 007). he primary system cools the reactor using Na; the secondary system generates power using a CO gas turbine. A supercritical CO gas turbine can generate electricity at a high cycle thermal efficiency, even at modest temperatures of 500 550 C. he high thermal efficiency is attributed to markedly reduced compressor work near the critical point. In addition, the reaction between CO and Na is milder than that between H O and Na. A more reliable and economically advantageous power generation system is achievable by coupling the CO turbine cycle with the Na-cooled fast breeder reactor. In the supercritical CO turbine system, a partial cooling cycle is used to compensate a difference in heat capacity for the hightemperature low-pressure side and the low-temperature high-pressure side of the recuperators to achieve high cycle thermal efficiency. In our previous work, conceptual design of the system was carried out for conditions of reactor thermal power of 600 MW, turbine inlet condition of 0 Ma/57 C, recuperator 1 and effectiveness of 98%/95%, intermediate 1 Copyright 008 by ASME

heat exchanger (IHX) pressure loss of 8.65%, turbine adiabatic efficiency of 93%, and compressor adiabatic efficiency of 88%. Results revealed that high cycle thermal efficiency of 43% can be achieved (Muto, Y., 006). In this cycle, three different compressors are included: a low-pressure compressor (LC), a high-pressure compressor (HC), and a bypass compressor (BC). In the compressor regime, the values of properties such as specific heat, density, and so on vary sharply and nonlinearly, dependent on pressure and temperature. he changes on compressor design imparted by the respective influences of such properties should be clarified. o obtain experimental data for the compressor performance in the field of near critical point, a supercritical CO compressor test project was started at the okyo Institute of echnology in June 007 with funding from MEX, Japan. In this project, a small centrifugal CO compressor is fabricated and tested. In FY 007, components of the test loop will be fabricated. In FY 008, test compressor will be fabricated and installed into the test loop. During FY 009, tests will be carried out. In this paper, the concept of the test loop and component designs for the cooler, heater, and control valves are introduced. A computer simulation program of steady state operation was developed based on detailed designs of components and preliminary designs of the compressor. A test operation regime is drawn for the test parameters. A Na-COOLED FAS REACOR SUERCRIICAL CO GAS URBINE SYSEM.1 Outline of a Na-cooled fast reactor supercritical CO gas turbine system A Na-cooled fast reactor supercritical CO gas turbine system is presented in Fig. 1. he reactor core is cooled using liquid Na; high-temperature Na energy is transferred to supercritical CO at intermediate heat exchanger (IHX) in this system. High-pressure and high-temperature CO gas enter the gas turbine and generate electricity; heat is transferred at the recuperators (RHX1 and RHX) from high temperature and Reactor 57ºC IHX 300 MW 388 ºC Intercooler LC HC BC recooler RHX RHX 1 urbine low-pressure CO to low temperature and high-pressure CO, and flows to the intermediate heat exchanger. he pressure of CO is changed from 6 Ma to 0 Ma; its temperature is changed from 37 C to 57 C in this system. he critical point of CO is 7.38 Ma and 31 C. hysical properties of CO were calculated using ROAH (Ito.., 001). hen they change significantly in the vicinity of the critical point. he specific heat of CO in the vicinity of the critical point is shown in Fig.. Specific heat is a function of pressure and temperature. Specific heat(kj/kg/k) 50 45 40 35 30 5 0 15 7.5Ma 8Ma 7.38M 10 10Ma 6Ma 5 5Ma 0 0 10 0 30 40 50 60 70 80 emperature(ºc) Fig. CO specific heat around the critical point he following subjects must be clarified for this system. 1. Development of a high-efficiency recuperator which affects system efficiency directly.. Stable operability of the compressor in a wide range from sub-critical up to supercritical conditions. 3. Realization of stable CO gas flow over a wide range from subcritical to supercritical conditions in this system. 4. Corrosion between super critical CO gas and materials. 5. Chemical reaction between super critical CO gas and materials.. Supercritical CO gas turbine generating system test he key components of the supercritical CO gas turbine system test apparatus are described in.1; items 1,, and 3 are the compressor and recuperator. he recuperator is a microchannel heat exchanger (MCHE) (Ishizuka,., 005; suzuki, N., 005; Kato, Y., 005; Nikitin, K., 004). Flow channels of MCHE were made by chemical etching on a stainless steel plate; they were made by diffusion bonding with combining of those chemically etched plates. he strength of diffusion bonded plates is almost equal to that of the mother material. he hydraulic diameter of MCHE is rather small and MCHE has good heat transfer ability. he CO gas condition of the recuperator is subcritical CO gas on the hot side and supercritical CO on the cold side for a Na-cooled fast reactor supercritical CO gas turbine system. he thermal efficiencies of the recuperator are shown in Fig. 3: they are very high values of ca. 98% to more than 99% (Ishizuka,., 005). Fig. 1 Na-cooled fast reactor CO gas turbine system Copyright 008 by ASME

Effectiveness η (-) 1.00 0.98 0.96 0.94 0.9 0.90 3 4 5 6 7 Average Re 10-3 (-) Fig. 3 hermal efficiencies of the recuperator (hot side) Studies of CO gas turbine system tests to solve.1, items 1 5 described above were conducted with funding from MEX, Japan (Furukawa,., 006; Ishizuka,., 006; Ishikawa, H., 006; Kato, Y., 007; Sato, H., 006). Regarding.1, items 1,, and 3, a supercritical CO test apparatus with reciprocating compressors was fabricated and tests were performed. Results confirmed that thermal hydraulic action of supercritical CO gas is operational with stable conditions at a steady state and transient condition, but small fluctuations were observed in pressure, temperature, and flow rates. However, the fluctuation of the flow rate is great; this fluctuation is attributed to the reciprocating compressor. A test apparatus, using a rotary compressor, that is operational without fluctuation is desired. A supercritical centrifugal compressor will be developed in this study. Regarding corrosion,.1, item 4, the tests were performed for 5,000 hours while maintaining conditions of 10 Ma and 600 C. Results confirmed that stainless steel 316 (316FR) developed for fast reactor in Japan has good anti-corrosion characteristics under those CO conditions. Corrosion tests of supercritical CO and plant material will be done under the conditions of CO pressure with 0 Ma. Regarding the reaction between CO and material, described in.1, item 5, the continuous reaction occurred scarcely or on a very small scale. It was mild or nonexistent at temperatures less than 550 C, which is a condition of CO for the Na-cooled fast reactor gas turbine system. he compressor type of an actual plant system is assumed to be centrifugal or axial, although the former tests were done using a reciprocating compressor. Compressors of actual plants function at the region across the critical point. It is necessary to develop a high-performance compressor that is operable across the CO critical point under a stable condition. 3. SUERCRIICAL CO COMRESSOR ERFORMANCE ES AARAUS 3.1 Outline of the supercritical CO compressor performance test apparatus A conventional CO compressor is usually operated in a region that is far away from the CO critical point. On the other hand, the inlet fluid condition of the compressor is a subcritical condition and the outlet condition of its supercritical condition in applying the Fast Breeder Reactor (FBR) real plant system. herefore, the compressor is operated across the critical point in a real plant system. hysical properties of CO change significantly in the vicinity of the critical point, especially for specific heat. his study develops the CO compressor working near the critical point. A compressor will be manufactured and tested to confirm the performance in the simulated area. he conceptual design of the compressor used for the real plant will be performed. A supercritical CO test apparatus is going to be built to obtain compressor performance data. In this test, compressor thermal hydraulic test data are obtained for various CO gas flow rates, pressures, and temperatures. he main components and instrument gauges of this compressor thermal hydraulic test apparatus are the compressor, cooler, heater, expansion valves, and mass flow meters. A diagram of this test apparatus is portrayed in Fig. 4. Symbol : emperature : ressure F: Flow rate D: Differential pressure E: Electric power ω:rotational rate V. pump 1 5.0 kg/s F 11 compressor 43 C, 7.48 Ma ress. tank 3 ank 10 Flow contr. valve F D 4 9 4-1 5.contr. valve Expansion Cooler valve 6 4- F 7 8 CO cylinder Fig.4 est apparatus system diagram Heater Driving motor 1 E M Control system ω 35 C 6.8 Ma D 3 Copyright 008 by ASME

3. est apparatus operating method Compressor performance test with CO gas will be done using the supercritical CO thermal hydraulic test apparatus. he test apparatus operation method is shown. First, the test apparatus should be evacuated using a rotary vacuum pump. hen, CO is charged from the CO cylinder to the test apparatus. he compressor will be operated at a low rotational speed (low flow rate). he test apparatus flow rate is controlled by the flow control valve. he heater and cooler control the temperature. ressure is controlled roughly by the expansion valve, and is controlled finely using the pressure control valve. Much more CO should be supplied when the pressure of the test apparatus is too low. In contrast, when the pressure is too high, the CO in the test apparatus should be purged. All control valves should be opened to avoid unstable flow when the compressor starts to operate. Compressor performance tests will be done by changing the pressure, temperature, flow rate, and compressor rotation speed. Figures 5 and 6 depict the test apparatus. he CO flow direction is shown by arrows in these figures. he test apparatus is ca. 7 m long,.4 m wide, and 1.7 m high. cooler compressor heater CO tank Fig. 5 lan view of the test apparatus cooler CO tank 3.3 Design of the supercritical CO thermal hydraulic test apparatus he position of maximum pressure and temperature in this test apparatus is at the compressor outlet. Design conditions are as follows. Maximum allowable test condition: compressor outlet pressure, 9.6 Ma compressor outlet temperature, 150 C compressor flow rate, 6 kg/s Rated condition: compressor inlet pressure, 6.8 Ma outlet pressure, 7.48 Ma compressor inlet temperature, 35 C outlet temperature, 43 C flow rate, 5 kg/s driving motor power of compressor, ca. 0 kw he allowed initial working pressure of the safety valve is several percent below the set point. Compressor performance tests should be done at the maximum pressure of 9.6 Ma. herefore, the design pressure of the test apparatus is set at 11 Ma. he compressor is a centrifugal type; the driving motor can change its rotational speed. he CO is cooled using city water at a cooler; the maximum removal heat capacity is 40 kw. he cooler structure is an annular tube type; CO flows through the inner tube and water flows through the annular part. he CO is heated at the heater, which is an indirect electric heater; its maximum heat capacity is 8. kw. otal pressure in the test apparatus is determined as the amount of CO inventory; the compressor inlet pressure is controlled mainly by an expansion valve, a pressure control valve, and a flow control valve in Fig. 4. he flow rate is dependent on the compressor rotational speed. 5000 compressor heater CO tank unit:mm Fig. 6 Front view of the test apparatus 3.4 Compressor design and its performance characteristics he compressor is a centrifugal type. his compressor will be operated in the vicinity of the CO critical point. he flow rate is controlled by changing the rotational speed; the maximum rotational speed is designed to be 14000 rpm. he compressor dimensions are as follows: Impeller inlet mean diameter 38 mm Impeller outer diameter 110 mm Impeller outlet depth 3.4 mm Diffuser inlet diameter 118 mm he centrifugal compressor section is portrayed in Fig. 7. he form of the compressor is approximately a cylinder: its length is 880 mm; its outer diameter is 360 mm. inlet tube impeller rotor stator Fig. 7 Centrifugal compressor section 1700 4 Copyright 008 by ASME

he compressor pressure ratio (= / 1 ; 1, inlet pressure;, outlet pressure) vs. the flow rate changing compressor rotational speeds as parameters are calculated using a computer program. he results are presented in Fig. 8. In that figure, the compressor pressure ratio is calculated under rated conditions and the inlet pressure is 6.8 Ma; the inlet temperature is 35 C. As depicted in Fig. 8, there is a maximum pressure ratio at each compressor rotational speed. he pressure ratio and flow rate increase with the rotational speed. For this study, those data will be obtained for evaluation of the compressor performance. CO inlet 1500 Water outlet unit:mm ressure ratio ( /1) 1.18 1.16 1.14 1.1 1.1 1.08 1.06 1.04 1.0 1 1000 rpm 10000 rpm 8000 rpm 6000rpm 4000 rpm 0.98 0 4 6 8 Flow rate (kg/s) Fig. 8 Compressor performance chart 3.5 Design of main components 14000 rpm 3.5.1 Cooler 3.5.1.1 Cooler design he heat sources of this test apparatus are a compressor and heater; the main heat sink of this test apparatus is a cooler with 40 kw capacities. his cooler structure is an annular tube type, the CO gas flows through the inner tube and cooling water flows through the annular channel. his annular tube comprises straight pipes and bent pipes. he total tube length is decided by evaluating the heat load. he flow direction of CO gas and water is counter-current. Heat is exchanged along the straight pipe. he swirler is set inside the tube to promote heat transfer. he rated conditions of the cooler are 6.8 Ma CO side inlet pressure, 37 C inlet temperature, and a 5.0 kg/s flow rate. he maximum design condition of CO velocity in a tube is less than 10 m/s and the pressure drop is less than 50 ka in this cooler. he designed maximum water flow rate is 1.0 kg/s, and the pressure is less than 0.5 Ma. he designed CO channel tube inner diameter/outer diameter are 65.9/76.3 mm; the water channel annular tube inner diameter/outer diameter are 83.1/89.1 mm. he total length of CO channel is 19 m. he designed cooler configuration is shown in Fig. 9. 700 Water inlet Fig. 9 Configuration of the cooler CO outlet 3.5.1. hermal hydraulic calculation of the cooler hermal hydraulic performance was calculated using a newly developed computer program. Regarding the calculation model, the CO pipe is divided into some meshes along the flow direction. he heat exchange between CO and water is calculated by solving heat transfer and heat transport equations for each mesh. he Dittus-Boelter heat transfer coefficient is used to calculate the heat transfer (JSME, 001). 0.8 0.4 α = 0.03 Re r (1) he pressure drop of CO is calculated using the equation of Drew et al. (JSME, 001). 0.3 f = 0.00140 + 0.15 Re () Heat transfer is calculated along the straight pipe only; the pressure drop is calculated along the entire pipe, including the bent pipe. he CO pipe diameter is decided to restrict the maximum CO velocity to less than 10 m/s at the rated condition. he pipe type is 65A-Sch40, where the adopted pipe outer diameter and inner diameter are, respectively, 76.3 mm and 65.9 mm. he outer diameter of the outside pipe for the water channel is 89.1 mm; its inner diameter is 83.1 mm. A connecting pipe is used to connect the water outlet and the inlet part. he straight pipe length is determined as.7 m for each step. he total pipe length is decided by the total heat load. Calculation results of the cooler are shown. Heat transfer from CO to water (heat load) is mainly dependent on the water temperature and flow rate. Figure 10 shows the heat load vs. the water flow rate. he city water temperature is dependent on the season in Japan. he maximum city water temperature in summer is about C; the average city water temperature through four seasons is around 15 18 C. Its minimum temperature is about 10 C. he necessary water flow rate is less than 1 kg/s if the heat load is less than 40 kw. he swirler effect was considered negligible: it was ignored. he calculated pressure loss of CO is presented in Fig. 11. he CO pressure loss is dependent on both the flow rate and physical properties. he CO pressure loss near the rated condition of this test apparatus (5 kg/s) is kept to less than 50 ka. 5 Copyright 008 by ASME

3.5. Heater design he electric heater is located at the upper flow of the compressor. he heater heats the CO to a designated temperature, enabling fine control of the compressor inlet CO temperature. he electric heater is of an indirect heating type; it is wound on the outer surface of a pipe whose inner diameter is 65.9 mm. A swirler is set inside the pipe to promote heat transfer to CO gas. Heat transfer from the electric heater to CO gas is calculated by evaluating CO thermal hydraulics and heat conduction inside the thermo cement. he total length of the electric heater is 4.4 m. Its capacity is 8. kw. he heater design is presented in Fig. 1. CO heat load (kw) 80 70 60 50 40 30 0 10 in=10ºc in=ºc 0 0 0.5 1 1.5 water flow rate (kg/s) Fig.10 Cooler heat load vs. water flow rate ressure loss (ka) 70 60 50 40 30 0 10 in =6.8Ma in=80º C Fig. 1 Heater configuration in=14ºc in=18º C 0 0 4 6 8 CO flow rate (kg/s) in=37ºc in =60ºC in=5ºc Fig.11 CO pressure loss in the cooler CO l 3.5.3 Control valve and other parts he pressure and flow rate are controlled mainly using the expansion valve (pressure control), pressure control valve (fine pressure control), and flow control valve (flow control). Valve characteristics are expressed as a C v value (Capacity value); the pressure loss of each control valve is mainly dependent on the degree of valve opening (x). he control valve pressure loss ( ) is calculated using x, as 1 4 f C = where the following pertain. f C ( CV ) = v, cal 3600 406 10. x C C cal ( x log ) 10 V, 80 V = 10 3600 m& = 4140 ( ) ρ ρ 1 N air, N he main pipe outer diameter is 65 mm. Special union connectors are used to realize a compact connection between components and pipes. Figure 13 presents an example of a special union connector. he size is determined by the connecting pipe. he pipe and both connectors 1 & are welded. 50 weld pipe connector ( ) 1 V m ρ ρ N 49.5 air, N connector pipe 3.5.3 Measurement system Main measurement items are pressure, temperature, flow rate, differential pressure, electric power, and rotational speed, which are stored in the data acquisition system. hose measurement positions are portrayed in Fig. 4. he CO flow rate is measured at three different positions using Coriolis flow meters. he total flow rate of the loop is measured using -inch flow meters, for which the flow range is 0.6 6 kg/s, with accuracy of ±0.1% at a maximum flow rate (6 kg/s) and ±0.8% at the minimum flow rate (0.6 kg/s). Both flow rates after the pressure control valve and the flow control valve are measured using a one-inch flow meter in each which flow range is 0.3 3 kg/s. Its accuracy is ±0.11% at the maximum & 1 Fig. 13 Union connector C weld connector 1 connector V unit:mm (3) (4) (5) (6) 6 Copyright 008 by ASME

flow rate (3 kg/s), and ±0.0% at the minimum flow rate (0.3 kg/s). 3.6 Calculation of the test apparatus for thermal hydraulic performance A newly developed computer program calculated the thermal hydraulics of the designed supercritical CO thermal hydraulic test apparatus. he calculation flow chart is presented in Fig. 14. Data input Assume m Assume Calculation of compressor enthalpy increasing,cal = Assume m B Assume m cv YES ressure loss calc. of expansion valve line Dp 4exp7 and pressure control valve line Dp 4pcv7 Dp 4exp7 = Dp 4pcv7 he calculated results are presented in Fig. 15. Compressor rotational speeds are shown from 4000 rpm to 14000 rpm in this figure. he pressure ratio and flow rate increase as the compressor rotational speed increases. Line A-A shows loop characteristics at some loop conditions, which are the rated compressor inlet pressure and inlet temperature. When loop conditions are changed, such as the control valve status, CO pressure and temperature, and shifted line A-A, the loop operable region is calculable using the computer program. When control valves are fully opened, another operational line, B-B, is obtained. In Fig. 15, the operational area of the loop and the compressor are shown as areas enclosed by lines A-A and B-B. he pressure ratio of 1.1 can be realized at around 13000 rpm. hat result reveals that the intended compressor performance tests in the vicinity of the critical point can be well conducted. ressure ratio ( / 1) 1.18 1.16 1.14 1.1 1.1 1.08 1.06 1.04 1.0 1 14000 rpm 1000 rpm 10000 rpm 8000 rpm 6000 rpm 4000 rpm A B 0.98 0 4 6 8 Flow rate (kg/s) Fig. 15 Compressor performance and loop characteristics A B Change m ho YES Calculation of cooler 4. SUERCRIICAL CO COMRESSOR ERFORMANCE ES ROJEC SCHEDULE ressure loss calc. of flow control line VO 10,cal = YES Calculation of heater 1,cal, 1,cal A supercritical CO compressor test project was started at the okyo Institute of echnology on June 007 with funding from MEX, Japan. During FY 007, a small centrifugal CO compressor was designed. Other test loop components were manufactured. During FY 008, a test compressor will be fabricated and installed into the test loop. In FY 009, tests will be carried out. 1,cal = 1 YES 1,cal = 1 END YES Fig. 14 Loop characteristic calculation flow chart 5. CONCLUSION 1. he compressor and the test loop were designed to simulate thermal hydraulic characteristics of a Na-cooled fast reactor supercritical CO gas turbine system with a centrifugal compressor. he components, except for the compressor, were commercially manufactured products. 7 Copyright 008 by ASME

. Main specifications for the rated condition are as follows: Inlet pressure of compressor = 6.8 Ma ressure rate = 1.1 Flow rate = 5 kg/s Inlet temperature = 35 C 3. A computer simulation program of static operation was developed based on the detailed design of cooling components and the preliminary compressor design. 4. he compressor performance was calculated and pressure ratio data showing the compressor performance were obtained using a computer program. 5. A compressor operational map with the test loop was obtained; results confirm that this centrifugal compressor performance test can be performed in the vicinity of the CO critical point using this test loop. 6. Compressor performance tests will start next year. MENCLAURE BC: Bypass compressor C v : Capacity value D: Differential pressure (a) E: Electric power (kw) f: Friction factor (-) F: Flow rate (kg/s) h: Enthalpy (J/kg) HC: High pressure compressor LC: Low pressure compressor : ressure (a) r: randtl number (-) Re: Reynolds number (-) rpm: Rotation per minute (1/min.) : emperature ( C) x: Valve open degree (%) ω: Rotation rate (1/s) m& : Mass flow rate (kg/s) α: Heat transfer coefficient (J/ (m * C)) ρ: Density (kg/m) Subscript: 1: Inlet; : Outlet; air: Air; N: Normal condition ACKWLEDGMENS his study is the result of Study of Na-cooled fast reactor supercritical CO turbine system entrusted to okyo Institute of echnology by the Ministry of Education, Culture, Sports, Science and echnology of Japan (MEX). REFERENCES Dostal, V., et al. 00. A supercritical CO gas turbine power cycle for next-generation nuclear reactors, roc.icone-10, 00 Furukawa,., Aoto, K., Miyake, O., et al., 006, Supercritical CO Gas urbine Fast Reactor, (5) Corrosion test of the Structural Material in Supercritical CO, roceeding of 006 Fall Meeting of AESJ, Sept.7-9, 006 Ishizuka,., Kato, Y., Muto, Y., Nikitin, K.., Ngo, L.., Hashimoto, H., 005 hermal-hydraulic characteristics of a printed circuit heat exchanger in a supercritical CO loop. he 11 th International opical Meeting on Nuclear Reactor hermal-hydraulics (NUREH-11), Avignon, France, October -6, 005 Ishizuka,., Kato, Y., Muto, Y., 006, Supercritical CO Gas urbine Fast Reactor, (1) roject Outline, roceeding of 006 Fall Meeting of AESJ, Sept.7-9, 006 Ishikawa, H., Miyahara, S., Yoshizawa, Y., 006, Supercritical CO Gas urbine Fast Reactor, (6) Experimental Study of Sodium/Carbon Dioxide Reaction, roceeding of 006 Fall Meeting of AESJ, Sept. 7-9, 006 Ito,. et al., 001 ROAH: A rogram ackage for hermo-hysical roperties of Fluid. Version 10., Corona ublishing, 001. JSME, 001, JSME Data Book, Hydraulic Losses in ipes and Ducts. 8, 001 and Heat ransfer (4th Edition), 5, 001. JSME, 001, JSME Data book : Heat ransfer 4th Edition, 001 Kato, Y., Ishizuka,., Muto, Y., et al., 007, Supercritical CO Gas urbine Fast Reactors. roceeding of ICA 007, May 13-18, 007, Nice, France Kato, Y., Muto, Y., Ishizuka,., et al., 005 Design of Recuperator for the Supercritical CO urbine Fast Reactor. roceeding of ICA05, May 15-19, 005, Seoul, Korea Kato, Y., suzuki. N., Ishizuka,., 005 New Microchannel Heat Exchanger for Carbon Dioxide Cycle. 7th IIR Gustav Lorentzen Natural Working Fluids Conference. 30 August - 1 Sept. 005, Vicenza, Italy Muto, Y. et al., 007 Efficiency Improvement of the Indirect Supercritical CO urbine System for Fast Reactors by Applying Micro-channel Intermediate Heat Exchanger, roceeding of ICA 007, May 13-18, 007,Nice,France Muto, Y., Kato, Y., 006 urbomachinery Design of Supercritical CO Gas urbine Fast Reactor, roc. 006, Int l. Congress on Advances in Nuclear ower lant (ICA 06), Reno, Nevada, USA. June 4-8, aper #6094, 006 Nikitin, K., Kato, Y., and Ngo, L. 004. rinted Circuit Heat Exchanger thermal-hydraulic performance in Supercritical CO experimental loop. 6 th IIR Gustav Lorentzen National Working Fluids Conference in UK, August/004 Sato, H., Miyake, O., Ishizuka,., et al., 006, Supercritical CO Gas urbine Fast Reactor, (4) Cycle Mockup est, roceedings of 006 Fall Meeting of AESJ, Sept. 7-9, 006 suzuki, N., Ishizuka,., Kato, Y., 005, High performance printed circuit heat Exchanger, roceeding of Heat ransfer in Components and Systems for Sustainable Energy echnologies (Heat SE 005), April 5-7, 005, Grenoble, France 8 Copyright 008 by ASME