Temperature Transients in a Triple Heat Exchanger

1984 ◽  
Vol 198 (3) ◽  
pp. 145-154
Author(s):  
P C Chiu ◽  
E H K Fung
Keyword(s):  
Heat Exchanger ◽  
Nuclear Reactor ◽  
Reactor Power ◽  
Solar Heating ◽  
Inlet Temperature ◽  
Exchange Processes ◽  
Flow Experiments ◽  
Heating Plant ◽  
Reactor Power Plant ◽  
Secondary Fluid

A triple heat exchanger, so called because there are three heat exchange processes taking place in it, was built to simulate the system behaviour of a nuclear reactor power plant or a solar heating plant which is characterized by the two circulating loops of the fluid flow. Experiments were carried out to study the temperature transients under disturbances in secondary fluid inlet temperature and power output from immersion heaters. Numerical results were obtained from the weighted residual formulation of the proposed dynamic model and they were shown to be in general agreement with the two sets of experimental responses.

Experimental Study of Temperature and Heating Power Variations on Natural Circulation Flow Phenomena in a Closed Rectangular Loop With Single Heating Channel

2020 ◽  
Author(s):  
Solomon Bello ◽  
Puzhen Gao ◽  
Yuqi Lin
Keyword(s):  
Flow Rate ◽  
Large Scale ◽  
Nuclear Reactor ◽  
Natural Circulation ◽  
Reactor Power ◽  
Heating Power ◽  
Inlet Temperature ◽  
Heating Channel ◽  
Flow Loop ◽  
Pressure Drops

Abstract Experimental investigation has been carried out in a closed loop rectangular natural circulation facility having a single heated macro channel dimensioned and built based on concepts of similarity and scale down circuit similar to the primary loop of a Nuclear reactor. The study aims to observe and critically analyze the thermal hydraulic parameters (Temperature Variation, Heating Power rises) as it affects transfer of heat by the NC flow along its hydraulic circuit at predetermined inlet subcooled set and sustained at 40°C, 50°C, 60°C and 80°C by regulating the coolant flow rate in the secondary loop. Heating channel power varies between 7kW – 13kW to portray several conditions of the reactor power in response to temperature changes base on the inlet temperature as a way of sustaining single-Phase flow through the flow loop while suppressing instabilities in the fluid circulation. Real-time signals of thermal hydraulic responses are observed via a graphical interface for data acquisition when stable flow or self-sustained flow oscillations are achieved. Results were analyzed at the (1) inlet and outlet of heater, (2) along the heated section and (3) inlet and outlet of condenser (4) the entire Loop. Pressure drops and Flow rate with respect to Temperature Difference was also analyzed to contribute for the acquisition of important data of natural circulation phenomena to be used for the design of large scale (prototypical) NC facility.

Exergy and Thermoeconomic Analysis of a Solar Air Heating Plant

2014 ◽  
Author(s):  
Miguel A. Lozano ◽  
Carla Mancini ◽  
Luis M. Serra ◽  
Vittorio Verda
Keyword(s):  
Heat Exchanger ◽  
Solar Energy ◽  
Ambient Air ◽  
Solar Heating ◽  
Thermodynamic Efficiency ◽  
Water Tank ◽  
Water Storage Tank ◽  
Air Heating ◽  
Productive Structure ◽  
Heating Plant

The aim of this work is to present the energy, exergy and thermoeconomic analysis of a hypothetical solar air heating plant located in Zaragoza, Spain. The plant consists mainly of four parts: 1) a field of solar collectors, 2) a water tank storage, 3) a heat exchanger where heat energy is transferred from the collectors to the water storage tank, and 4) a water to air heater heat exchanger. Circulating pumps, pipes and fan have also been considered. In a previous work of the authors the design variables of the system were optimally determined from a conventional economic approach. In this paper, a productive structure for the plant has been proposed and energy losses and exergy destructions (or irreversibility) have been calculated. Energy and exergy efficiencies have also been determined for each of the components and the whole system. Moreover, the costs of internal flows have been dynamically calculated for the time period under consideration. The very specific features of solar heating systems: thermal energy storage as well as continuous variation of solar radiation and energy demand (seasonal and throughout the day) impose important difficulties, which in our opinion have not been deeply studied yet in current methodologies. The major conclusions are: i) energy, exergy and thermoeconomic analyses following a dynamic approach is very sensitive to the reference environment (ambient air temperature), ii) the same productive structure can and must be used for all of them, iii) solar energy should be considered as a high quality source and thermodynamic efficiency of solar heating plants is very low (2.5% in our case), and iv) a dynamic analysis of the process of cost formation through the different components reveals interesting and valuable information about the physics and economics of solar energy conversion systems.

scholarly journals Numerical investigation on thermal performance and flow characteristics of Z and S shape printed circuit heat exchanger using S-CO2

2019 ◽  
Vol 23 (Suppl. 3) ◽  
pp. 757-764
Author(s):  
Yuan-Sheng Lin ◽  
Qi Jing ◽  
Yong-Hui Xie
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Thermal Performance ◽  
Nuclear Reactor ◽  
High Efficiency ◽  
Flow Characteristics ◽  
Energy Industry ◽  
Bend Angle ◽  
Inlet Temperature ◽  
Printed Circuit

As a high-efficiency compact heat exchanger, the printed circuit heat exchanger has been widely applied into nuclear reactor and energy industry. In the present paper, the thermal hydraulic performance of printed circuit heat exchanger based on S-CO2 Brayton power cycle has been numerically investigated for various channel shape and bend angle. A total of seven different shaped channels including straight, Z-10, Z-20, Z-30, S-10, S-20, S-30 are modeled, and evaluated according to the heat transfer and friction performances within the Reynolds number of 5000-30000. The inlet temperature/outlet pressure of hot channel and cold channel are 553 K/2.6 MPa and 381 K/8.5 MPa, respectively. The flow patterns, average Nusselt number, friction factor, and heat exchanger effectiveness are obtained. On the comprehensive consideration of heat transfer enhancement and friction, the S-20 channel produces the best thermal performance. This investigation has provided important reference data for the design of advanced printed circuit heat exchanger in the energy industry.

scholarly journals High-temperature nuclear reactor power plant cycle for hydrogen and electricity production – numerical analysis

2016 ◽  
Vol 10 ◽  
pp. 00105 ◽  
Author(s):  
Michał Dudek ◽  
Marek Jaszczur ◽  
Katarzyna Skolik ◽  
Mateusz Malicki ◽  
Ludwik Pieńkowski
Keyword(s):  
High Temperature ◽  
Numerical Analysis ◽  
Power Plant ◽  
Nuclear Reactor ◽  
Reactor Power ◽  
Electricity Production ◽  
Reactor Power Plant
Sign in / Sign up

Export Citation Format

Share Document