Design and Analysis of a Meso-Scale Refrigerator

Abstract The preliminary design and analysis of a meso-scale refrigerator is presented here. The device is to be designed out of layers of silicon wafers bonded together and is to be fabricated through the techniques of microelectronics. The intended application of the device is an integrated heat removal system for electronics or photonic chips or modules. The paper presents a functional decomposition of the entire system, thermodynamic feasibility analysis, alternative configurations for two of the functions: actuation and compression, and parametric analysis for two alternative candidates for compressor actuation. A set of reasonable design requirements is first formulated. Overall function of the devices is decomposed into nine major sub-functions. Comparison of different alternatives for compression and actuation suggests that electrostatic actuation integrated with centrifugal compression is a viable option. Two different ways to implement electrostatic actuation are considered in details: variable capacitance motor and electrostatic induction motor. A set of design relations and criteria needed to obtain the optimal design of each motor is presented along with a discussion on relative effects of the main design parameters.

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Optimization and Analysis for Passive Residual Heat Removal System of an Integral Pressurized Water Reactor

Volume 4: Codes, Standards, Licensing and Regulatory Issues; Student Paper Competition ◽

10.1115/icone17-75503 ◽

2009 ◽

Author(s):

Shoubao Dai ◽

Minjun Peng ◽

Jiange Liu

Keyword(s):

Natural Circulation ◽

Heat Removal ◽

Design Parameters ◽

Pressurized Water Reactor ◽

Pressurized Water ◽

Secondary Loop ◽

Heat Removal System ◽

Removal System ◽

Peak Value ◽

Residual Heat

The characteristics of passive safety systems for an integral pressurized water reactor (IPWR) are quite different from the general reactor because of special configuration and dangerous run environment. Passive residual heat removal system (PRHRS) for the IPWR with three-interknited natural coolant circulation loops, safely remove the core decay heat to the ultimate heat sink. Using RELAP5/MOD3.4 code to simulate this system during the reactor trip, analyses the steady-state and transient-state thermohydraulic behaviors for the IPWR and its PRHRS, and the effects of design parameters on the system. it is found that on the initial period of reactor trip, due to the establishment of the natural circulation in three loops uncompleted, the secondary loop pressure have the peak value. Through analyzing the effects of design parameters on the system, the PRHRS are optimized. The results show that the larger the residual heat exchanger (RHE) heat transfer area and the higher the height difference between the steam generator and the residual heat exchanger, the easier the establishment of the natural circulation in the third loop, but which make the peak value of the secondary loop pressure higher. According to set the compensating water tank, which is parallel connected to the RHE, can lighten the higher the peak value of the secondary loop pressure, and optimize the design of PRHRS.

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An Optimal Design Approach for the Decay Heat Removal System in PGSFR

Volume 1C, Symposia: Fundamental Issues and Perspectives in Fluid Mechanics; Industrial and Environmental Applications of Fluid Mechanics; Issues and Perspectives in Automotive Flows; Gas-Solid Flows: Dedicated to the Memory of Professor Clayton T. Crowe; Numerical Methods for Multiphase Flow; Transport Phenomena in Energy Conversion From Clean and Sustainable Resources; Transport Phenomena in Materials Processing and Manufacturing Processes ◽

10.1115/fedsm2014-21971 ◽

2014 ◽

Author(s):

Dehee Kim ◽

Jaehyuk Eoh ◽

Tae-Ho Lee

Keyword(s):

Heat Transfer ◽

Genetic Algorithm ◽

Heat Exchanger ◽

Heat Removal ◽

Design Parameters ◽

Dimensional System ◽

Decay Heat ◽

Gen Iv ◽

Heat Removal System ◽

Removal System

Sodium-cooled Fast Reactor (SFR) is one of the generation IV (Gen-IV) nuclear reactors. Prototype Gen-IV SFR (PGSFR) is a SFR being developed in Korea Atomic Energy Research Institute (KAERI). Decay Heat Removal System (DHRS) in the PGSFR has a safety function to make shutdown the reactor under abnormal plant conditions. Single DHRS loop consists of sodium-to-sodium decay heat exchanger (DHX), helical-tube sodium-to-air heat exchanger (AHX) or finned-tube sodium-to-air heat exchanger (FHX), loop piping, and expansion vessel. The DHXs are located in the cold pool and the AHXs and FHXs are installed in the upper region of the reactor building. The DHRS loop is a closed loop and liquid sodium coolant circulates inside the loop by natural circulation head for passive system and by forced circulation head for active system. There are three independent heat transport paths in the DHRS, i.e., the DHX shell-side sodium flow path, the DHRS sodium loop path through the piping, the AHX shell-side air flow path. To design the components of the DHRS and to determine its configuration, key design parameters such as mass flow rates in each path, inlet/outlet temperatures of primary and secondary flow sides of each heat exchanger should be determined reflecting on the coupled heat transfer mechanism over the heat transfer paths. The number of design parameters is larger than that of the governing equations and optimization approach is required for compact design of the DHRS. Therefore, a genetic algorithm has been implemented to decide the optimal design point. The one-dimensional system design code which can predict heat transfer rates and pressure losses through the heat exchangers and piping calculates the objective function and the genetic algorithm code searches a global optimal point. In this paper, we present a design methodology of the DHRS, for which we have developed a system code coupling a one-dimensional system code with a genetic algorithm code. As a design result, the DHRS layouts and the sizing of the heat exchangers have been shown.

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