Heat Pipe as a Passive Cooling System Driving New Generation of Nuclear Power Plants

The technology of the Heat Pipe (HP) system is very well known for scientists and engineers working in the field of thermal-hydraulic since its invention at Las Alamos Nation Laboratory around the 1960s time frame. It is a passive heat transfer/heat exchanger system that comes in the form of either a constant or variable system without any mechanical built-in moving part. This passive heat transfer system and its augmentation within the core of nuclear power reactors have been proposed in the past few decades. The sodium, potassium, or mercury type heat pipe system using any of these three elements for the cooling system has been considered by many manufacturers of fission reactors and recently fusion reactors particularly Magnetic Confinement Fusion (MCF). Integration of the heat pipes as passive cooling can be seen in a new generation of a nuclear power reactor system that is designed for unconventional application field such as a space-based vehicle for deep space or galaxy exploration, planetary surface-based power plants as well as operation in remote areas on Earth. With the new generation of Small Modular Reactor (SMR) in form of Nuclear Micro Reactors (NMR), this type of fission reactor has integrated Alkali metal heat pipes to a series of Stirling convertors or thermoelectric converters for power generation that would generate anywhere from 13kwt to 3Mwt thermal of power for the energy conversion system.

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Ways to heat hot water via the heat pipes

MATEC Web of Conferences ◽

10.1051/matecconf/201816809003 ◽

2018 ◽

Vol 168 ◽

pp. 09003

Author(s):

Peter Hrabovský ◽

Zuzana Kolková ◽

Jozef Matušov ◽

Patrik Nemec

Keyword(s):

Heat Transfer ◽

Heat Pipe ◽

Nuclear Power ◽

Heat Pipes ◽

Hot Water ◽

Temperature Range ◽

Thermal Output ◽

Actual Use ◽

Mechanical Elements ◽

The Way

The article deals various ways of heating hot water where heat is transferred by the basic phenomena of heat transfer theories, which take place on an innovative basis with the advantage of the absence of mechanical elements. The heat transfer in this case ensures a change in the phase-in phase of the working substance – the fluid – from which the thermal output and the efficiency of the device are derived. The devices described in this article work on the same principle of heat transfer. Each device is characterized by own construction and the principle of heat transfer. Heat pipes are classified according to the way of operation and the place of use. Subdivision of the heat pipe, in terms of its actual, use in the desired temperature range. At present, heating plants use cooling technologies (nuclear power, space stations, IT).

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Self-Propelling Cooling Systems: Back-Fitting Passive Cooling Functions to Existing Nuclear Power Plants

Volume 5: Fusion Engineering; Student Paper Competition; Design Basis and Beyond Design Basis Events; Simple and Combined Cycles ◽

10.1115/icone20-power2012-54382 ◽

2012 ◽

Author(s):

Dominik von Lavante ◽

Dietmar Kuhn ◽

Ernst von Lavante

Keyword(s):

Nuclear Power ◽

Power Plants ◽

Cooling System ◽

Electrical Power ◽

Reactor Core ◽

Passive Cooling ◽

Spent Fuel ◽

Cooling Systems ◽

Spent Fuel Pool

The present paper describes a back-fit solution proposed by RWE Technology GmbH for adding passive cooling functions to existing nuclear power plants. The Fukushima accidents have high-lighted the need for managing station black-out events and coping with the complete loss of the ultimate heat sink for long time durations, combined with the unavailability of adequate off-site supplies and adequate emergency personnel for days. In an ideal world, a nuclear power plant should be able to sustain its essential cooling functions, i.e. preventing degradation of core and spent fuel pool inventories, following a reactor trip in complete autarchy for a nearly indefinite amount of time. RWE Technology is currently investigating a back-fit solution involving “self-propelling” cooling systems that deliver exactly this long term autarchy. The cooling system utilizes the temperature difference between the hotter reactor core or spent fuel pond with the surrounding ultimate heat sink (ambient air) to drive its coolant like a classical heat machine. The cooling loop itself is the heat machine, but its sole purpose is to merely achieve sufficient thermal efficiency to drive itself and to establish convective cooling (∼2% thermal efficiency). This is realized by the use of a Joule/Brayton Cycle employing supercritical CO2. The special properties of supercritical CO2 are essential for this system to be practicable. Above a temperature of 30.97°C and a pressure of 73.7bar CO2 becomes a super dense gas with densities similar to that of a typical liquid (∼400kg/m3), viscosities similar tothat of a gas (∼3×105Pas) and gas like compressibility. This allows for an extremely compact cooling system that can drive itself on very small temperature differences. The presented parametric studies show that a back-fitable system for long-term spent fuel pool cooling is viable to deliver excess electrical power for emergency systems of approximately 100kW. In temperate climates with peak air temperatures of up to 35°C, the system can power itself and its air coolers at spent fuel pool temperatures of 85°C, although with little excess electrical power left. Different back-fit strategies for PWR and BWR reactor core decay heat removal are discussed and the size of piping, heat exchangers and turbo-machinery are briefly evaluated. It was found that depending on the strategy, a cooling system capable of removing all decay heat from a reactor core would employ piping diameters between 100–150mm and the investigated compact and sealed turbine-alternator-compressor unit would be sufficiently small to be integrated into the piping.

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Fundamental Heat Transfer Experiments of Heat Pipes for Turbine Cooling

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2818186 ◽

1998 ◽

Vol 120 (3) ◽

pp. 580-587 ◽

Cited By ~ 4

Author(s):

S. Yamawaki ◽

T. Yoshida ◽

M. Taki ◽

F. Mimura

Keyword(s):

Heat Transfer ◽

Heat Pipe ◽

Cooling System ◽

Infrared Image ◽

Heat Pipes ◽

Performance Criteria ◽

Working Fluid ◽

Steel Shell ◽

Turbine Cooling ◽

Start Up

Fundamental heat transfer experiments were carried out for three kinds of heat pipes that may be applied to turbine cooling in future aero-engines. In the turbine cooling system with a heat pipe, heat transfer rate and start-up time of the heat pipe are the most important performance criteria to evaluate and compare with conventional cooling methods. Three heat pipes are considered, called heat pipe A, B, and C, respectively. All heat pipes have a stainless steel shell and nickel sintered powder metal wick. Sodium (Na) was the working fluid for heat pipes A and B; heat pipe C used eutectic sodium-potassium (NaK). Heat pipes B and C included noncondensible gas for rapid start-up. There were fins on the cooling section of heat pipes. In the experiments, and infrared image furnace supplied heat to the heat pipe simulating turbine blade surface conditions. In the results, heat pipe B demonstrated the highest heat flux of 17 to 20 W/cm2. The start-up time was about 6 minutes for heat pipe B and about 16 minutes for heat pipe A. Thus, adding noncondensible gas effectively reduced start-up time. Although NaK is a liquid phase at room temperature, the startup time of heat pipe C (about 7 to 8 minutes) was not shorter than the heat pipe B. The effect of a gravitational force on heat pipe performance was also estimated by inclining the heat pipe at an angle of 90 deg. There was no significant gravitational dependence on heat transport for heat pipes including noncondensible gas.

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Heat pipe based passive emergency core cooling system for safe shutdown of nuclear power reactor

Applied Thermal Engineering ◽

10.1016/j.applthermaleng.2014.07.004 ◽

2014 ◽

Vol 73 (1) ◽

pp. 699-706 ◽

Cited By ~ 22

Author(s):

Masataka Mochizuki ◽

Randeep Singh ◽

Thang Nguyen ◽

Tien Nguyen

Keyword(s):

Heat Pipe ◽

Nuclear Power ◽

Power Reactor ◽

Cooling System ◽

Nuclear Power Reactor ◽

Core Cooling

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Heat Transfer in the Ducts of the Cooling Systems of Traction Motors

International Journal of Engineering & Technology ◽

10.14419/ijet.v7i4.3.19824 ◽

2018 ◽

Vol 7 (4.3) ◽

pp. 315

Author(s):

A А. Aleksahin ◽

A V Panchu ◽

L A. Parkhomenko ◽

H V. Bilovol

Keyword(s):

Heat Transfer ◽

Heat Exchangers ◽

Nuclear Power ◽

Power Plants ◽

Cooling System ◽

Transfer Processes ◽

New Energy ◽

Working Media ◽

Artificial Heat ◽

The Impact

Requirements for increasing thermal efficiency heat exchangers, which lead to energy saving, material and reduction cost, and as a result of reducing the impact on the environment, led to the development and use of various methods of increasing heat transfer. These methods are called intensification of heat transfer processes. Intensification of heat and mass transfer processes is of great importance for making progress in improving the existing and creation of new energy and heat-exchange equipment. Among the ways of intensifying heat transfer, the swirling of flows of working media is one of the simplest and most common methods and is widely used in energy-intensive channels of nuclear power plants, heat exchangers, aeronautical and rocket and space equipment, chemical industry and other technical devices. We have proposed formulas to determine the cooling air velocity necessary to ensure the required temperature condition of the traction motor assemblies. Decrease in the power of fans in the cooling system using the artificial heat transfer intensification in the ducts was estimated based on the generalization of the results of calculations.

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Innovation structure combining inter-story isolation with passive cooling effect for AP1000 nuclear power plants

Engineering Computations ◽

10.1108/ec-12-2020-0748 ◽

2021 ◽

Vol ahead-of-print (ahead-of-print) ◽

Author(s):

Gangling Hou ◽

Yu Liu ◽

Tao Wang ◽

Binsheng Wang ◽

Tianshu Song ◽

...

Keyword(s):

Nuclear Power ◽

Power Plants ◽

Nuclear Power Plants ◽

Cooling System ◽

Design Method ◽

Passive Cooling ◽

Original Design ◽

Seismic Safety ◽

Lower Altitude ◽

Content Type

PurposeAn inter-story isolation structure (IIS) for AP1000 nuclear power plants (NPPs) is provided to resolve the conflict of seismic safety and the optimal location of air intakes.Design/methodology/approachThe effect of passive cooling system (PCS) is better with lower altitude of air intakes than that in the original design of AP1000 NPPs. Seismic performances of IIS NPPs, including the seismic responses, damping frequency bandwidth and seismic reduction robustness, are improved by combining the position of air intakes lower and the optimal design method.FindingsTheoretical analysis and numerical simulation are illustrated that the seismic reduction failure of IIS NPPs is the lowest probability of occurrence when PCS has highest working efficiency.Originality/valueThe IIS NPPs can transfer the contradiction between PCS work efficiency and seismic safety of NPPs to the mutual promotion of them.

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Summary of heat transfer processes and their comparative evaluation for capillary porous coatings in power plants

Safety and Reliability of Power Industry ◽

10.24223/1999-5555-2019-12-1-29-35 ◽

2019 ◽

Vol 12 (1) ◽

pp. 29-35

Author(s):

A. A. Genbach ◽

D. Yu. Bondartsev ◽

A. Y. Shelginsky

Keyword(s):

Heat Transfer ◽

Heat Exchange ◽

Power Plants ◽

Cooling System ◽

Heat Pipes ◽

High Heat ◽

Porous Structures ◽

Heat Exchange Surface ◽

Exchange Surface ◽

Thin Fi Lm

The crisis of heat exchange at boiling of water in porous structures used for cooling of heat-stressed surfaces of various aggregates is investigated. The study refers to thermal power installations of power plants. The experiments were carried out on a stand with heat supply from an electric heater. Cooling of heat-exchange surfaces was performed by water supply to porous structures with diff erent cell sizes. It is shown that in porous cooling systems of elements of heat and power plants processes of fl uid boiling take place, and at high heat fl ows it is possible to approach a crisis situation with overheating of the heat-exchange surface. The heat exchange processes are described, the infl uence of thermophysical properties of heat exchange surface is shown, and optimal sizes of porous structure cells are determined. A calculated equation is obtained for determining the critical heat fl ux at high pressures. The calculation of the critical load with respect to the examined porous structures was carried out with taking into account the underheating and fl ow rate, from which it follows that the underheating of the liquid enables to expand slightly the heat transfer capabilities in a porous cooling system. The experimental data of the investigated capillary porous cooling system operating under the joint action of capillary and mass forces are generalized, and its characteristics q=f(ΔT) are compared with boiling in large volume, heat pipes and thin-fi lm evaporators. The limits of diff erent capillary-porous coatings are given. High heat transfer boosting is provided by combined action of capillary and mass forces and has advantages in comparison with boiling in large volume, thin-fi lm evaporators and heat pipes. It is shown that the results of theoretical calculations conform well with experimental data.

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Fundamental Heat Transfer Experiments of Heat Pipes for Turbine Cooling

Volume 3: Heat Transfer; Electric Power; Industrial and Cogeneration ◽

10.1115/97-gt-438 ◽

1997 ◽

Cited By ~ 1

Author(s):

Shigemichi Yamawaki ◽

Toyoaki Yoshida ◽

Masanobu Taki ◽

Fujio Mimura

Keyword(s):

Heat Transfer ◽

Heat Pipe ◽

Cooling System ◽

Infrared Image ◽

Heat Pipes ◽

Performance Criteria ◽

Working Fluid ◽

Steel Shell ◽

Turbine Cooling ◽

Start Up

Fundamental heat transfer experiments were carried out for three kinds of heat pipes which may be applied to turbine cooling in future aero-engines. In the turbine cooling system with a heat pipe, heat transfer rate and start-up time of the heat pipe are the most important performance criteria to evaluate and compare with conventional cooling methods. Three heat pipes are considered, called heat pipe A, B and C, respectively. All heat pipes have a stainless steel shell and nickel sintered powder metal wick. Sodium(Na) was the working fluid for heat pipes A and B; heat pipe C used eutectic sodium-potassium(NaK). Heat pipes B and C included non-condensible gas for rapid start-up. There were fins on the cooling section of heat pipes. In the experiments, an infrared image furnace supplied heat to the heat pipe simulating turbine blade surface conditions. In the results, heat pipe B demonstrated the highest heat flux of 17 to 20 W/cm2. The start-up time was about 6 minutes for heat pipe B and about 16 minutes for heat pipe A. Thus adding non-condensible gas effectively reduced start-up time. Although NaK is a liquid phase at room temperature, the start-up time of heat pipe C (about 7 to 8 minutes) was not shorter than the heat pipe B. The effect of a gravitational force on heat pipe performance was also estimated by inclining the heat pipe at an angle of 90 degrees. There was no significant gravitational dependence on heat transport for heat pipes including non-condensible gas.

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