Thermo-economic analysis and optimization of the very high temperature gas-cooled reactor-based nuclear hydrogen production system using copper-chlorine cycle

Author(s):  
Qi Wang ◽  
Chunyu Liu ◽  
Run Luo ◽  
Xiaodong Li ◽  
Dantong Li ◽  
...  
Author(s):  
Shoji Takada ◽  
Kenji Abe ◽  
Yoshiyuki Inagaki

The high temperature isolation valve (HTIV) is a key component to assure the safety of a high temperature gas cooled reactor (HTGR) connected with a hydrogen production system, that is, protection of radioactive material release from the reactor to the hydrogen production system and combustible gas ingress to the reactor at the accident of fracture of an intermediate heat exchanger and the chemical reactor. The HTIV used in the helium condition over 900 °C, however, has not been made for practical use yet. The conceptual structure design of an angle type HTIV was carried out. A seat made of Hasteloy-XR is welded inside a valve box. Internal thermal insulation is employed around the seat and a liner because high temperature helium gas over 900 °C flows inside the valve. Inner diameter of the top of seat was set 445 mm based on fabrication experiences of valve makers. A draft overall structure was proposed based on the diameter of seat. The numerical analysis was carried out to estimate temperature distribution and stress of metallic components by using a three-dimensional finite element method code. Numerical results showed that the temperature of the seat was simply decreased from the top around 900 °C to the root, and the thermal stress locally increased at the root of the seat which was connected with the valve box. The stress was lowered below the allowable limit 120 MPa by decreasing thickness of the connecting part and increasing the temperature of valve box to around 350 °C. The stress also increased at the top of the seat. Creep analysis was also carried out to estimate a creep-fatigue damage based on the temperature history of the normal operation and the depressurization accident.


Author(s):  
M. G. McKellar ◽  
E. A. Harvego ◽  
A. M. Gandrik

An updated reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production has been developed. The HTE plant is powered by a high-temperature gas-cooled reactor (HTGR) whose configuration and operating conditions are based on the latest design parameters planned for the Next Generation Nuclear Plant (NGNP). The current HTGR reference design specifies a reactor power of 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 322°C and 750°C, respectively. The reactor heat is used to produce heat and electric power for the HTE plant. A Rankine steam cycle with a power conversion efficiency of 44.4% was used to provide the electric power. The electrolysis unit used to produce hydrogen includes 1.1 million cells with a per-cell active area of 225 cm2. The reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes a steam-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The overall system thermal-to-hydrogen production efficiency (based on the higher heating value of the produced hydrogen) is 42.8% at a hydrogen production rate of 1.85 kg/s (66 million SCFD) and an oxygen production rate of 14.6 kg/s (33 million SCFD). An economic analysis of this plant was performed with realistic financial and cost estimating The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost. A cost of $3.03/kg of hydrogen was calculated assuming an internal rate of return of 10% and a debt to equity ratio of 80%/20% for a reactor cost of $2000/kWt and $2.41/kg of hydrogen for a reactor cost of $1400/kWt.


2011 ◽  
Vol 133 (11) ◽  
Author(s):  
Shoji Takada ◽  
Kenji Abe ◽  
Yoshiyuki Inagaki

The high temperature isolation valve (HTIV) is a key component to assure the safety of a high temperature gas cooled reactor connected with a hydrogen production system for protections of radioactive material release from the reactor to the hydrogen production system as well as of combustible gas ingress to the reactor at the accident of fracture of an intermediate heat exchanger and the chemical reactor. However, the HTIV has not been made for practical use in the helium condition over 900°C yet. The conceptual structure design of an angle type HTIV was carried out. A seat made of Hasteloy-XR is welded inside a valve box. Internal thermal insulation is employed around the seat and a liner because the high temperature helium gas flows inside the valve. The inner diameter of the top of seat was set 445 mm based on fabrication experiences of valve makers. A draft overall structure was proposed based on the diameter of the seat. The numerical analysis was carried out to estimate the temperature distribution and stress of metallic components by using a three-dimensional finite element method code. Numerical results showed that the temperature of the seat was simply decreased from the top around 900°C to the root, and the thermal stress locally increased at the root of the seat, which was connected with the valve box. The stress was lowered below the allowable limit 120 MPa by decreasing the thickness of the connecting part and increasing the temperature of the valve box to around 350°C. The stress also increased at the top of the seat. Creep analysis revealed that the intactness of the HTIV is kept after the assumed operation cycles of the plant life as well as at the depressurization accident.


2008 ◽  
Vol 45 (11) ◽  
pp. 1215-1227 ◽  
Author(s):  
Hirofumi OHASHI ◽  
Nariaki SAKABA ◽  
Tetsuo NISHIHARA ◽  
Yukio TACHIBANA ◽  
Kazuhiko KUNITOMI

2019 ◽  
Vol 21 (1) ◽  
pp. 20 ◽  
Author(s):  
Ping Zhang ◽  
Jingming Xu ◽  
Lei Shi ◽  
Zuoyi Zhang

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