Plastic heat exchangers: a state-of-the-art review

International Journal of Heat and Mass Transfer

Deisenroth

2016

This paper presents an in-depth study of the thermal performance of a gas-to-liquid "webbed tube" polymer heat exchanger. The heat exchanger was fabricated from a thermally enhanced polymer composite, consisting of a Nylon 12 matrix filled with carbon fibers. A laboratory-scale prototype heat exchanger was built using injection molding and tested on a cross-flow air-to-water heat exchange apparatus. The thermal performance of this laboratory webbed-tube polymer composite heat exchanger is studied in depth through an extended set of experiments, application of existing empirical correlations, and detailed computational fluid dynamic (CFD) simulations. The laboratory webbed-tube heat exchanger prototype provided a maximum UA value of 1.8 W/K and a volume-specific heat transfer coefficient of 14 kW/m 3 K. The experimental results, in conjunction with numerical simulations, were used to determine an "effective" thermal conductivity of 1.8 W/m•K for the injection-molded nyloncarbon composite material in the webbed-tube heat exchanger configuration.

Section: Discussionmentioning

confidence: 88%

Section: Wthx Prototypementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Thermal performance of a polymer composite webbed-tube heat exchanger

Cevallos

International Journal of Heat and Mass Transfer

Deisenroth

2016

“…They were adopted for many industrial applications, such as pickling in steel manufacturing, heating of agitated reactor vessels, and heating/cooling of distilled water. The wide availability and versatility of polymers has since driven the interest of the research community toward the use of these materials in heat exchanger applications [2][3].…”

Section: Introductionmentioning

confidence: 99%

Incorporating Moldability Considerations During the Design of Polymer Heat Exchangers

Cevallos¹,

Gupta²,

Journal of Mechanical Design

2011

Recently, available formulations of thermally enhanced polymer composites are attractive in heat exchanger applications due to their low cost and improved corrosion resistance compared to the conventional metal options. This paper presents a systematic approach to the design of plate-fin heat exchangers made out of thermally enhanced polymer composites. We have formulated the design problem as the life cycle cost minimization problem. The integrated design model introduced here accounts for heat transfer performance, molding cost, and assembly costs. We have adopted well-known models to develop individual parametric models that describe how heat transfer performance, molding cost, and assembly cost varies as a function of the geometric parameters of the heat exchanger. Thermally enhanced polymer composites behave differently from the conventional polymers during the molding process. The desired thin walled large structures are expected to pose challenges during the filling phase of the molding process. Hence, we have utilized experimentally validated simulations to develop a metamodel to identify difficult and impossible to mold design configurations. This metamodel has been integrated within the overall formulation to address the manufacturability considerations. This paper also presents several case studies that show how the material and labor cost strongly influence the final design.

Modeling and Validation of a Prototype Thermally-Enhanced Polymer Heat Exchanger

Robinson

Cevallos

Volume 1: Advances in Aerospace Technology; Energy Water Nexus; Globalization of Engineering; Posters

et al. 2011

Polymer heat exchangers (PHXs) have received considerable attention since their invention more than 40 years ago due to their corrosion resistance, low density and low manufacturing cost. New polymer composites with higher strengths, thermal conductivities and thermal stability promise to bridge the performance gap between polymers and corrosion resistant metals. In the present study, PHX components were injection molded using thermally enhanced polyamide 12 resin and assembled into a crossflow finned-plate heat exchanger prototype. The prototype was implemented in an air-to-water experimental test apparatus and the heat transfer results were compared to an analytical model. This comparison confirmed that a polymer composite heat exchanger (PCHX) can offer significantly enhanced heat transfer relative to a pure polymer. A thermomechanical finite element model of the PCHX was developed and validated using experimental results. At fluid pressures near ambient, the heat transfer rate of the PCHX was 28% less than could be attained with an identical titanium heat exchanger. As fluid pressures increased, the through wall conduction resistance had a larger effect on heat transfer rate, reducing the performance of the PCHX relative to the titanium heat exchanger. Stress analysis of the thermally enhanced PCHX revealed that the stresses due to pressure loading were more sensitive to heat exchanger geometry, while the stresses due to thermal loading were more sensitive to material property anisotropy.