An insulation technique has been developed which contains a single or combination of materials to help minimize heat loss in actual industrial applications. For the petroleum industry, insulation for deep sea piping is one of the greatest challenges which would prevent the industry from meeting the high demand for oil through exploration into deeper ocean environments. At current seafloor depths (5,000∼10,000ft), pipeline insulation is essential in preventing pipeline blockage resulting from the solidification of paraffin waxes and/or hydrate formation which exist in crude oil. To maintain crude oil temperatures above the paraffin solidification point (68°C or 155°F), new and better insulation techniques are essential to minimize pipeline heat loss and maintain crude oil temperatures. Therefore, the objective of this investigation was to determine whether or not the thermal resistance of a new insulation concept, which involves IIT (Interstitial Insulation Technology) with screen wire, was greater than existing readily available commercial products through analytical modeling and experimentation. The model takes into account both conforming and nonconforming interfaces at the wire screen contacts within the interstitial space between coaxial pipes.

In addition, confirmation was needed to determine whether or not laboratory testing of simulated coupons translate to thermal performance for a prototype pipe segment that fabricated with two layers of low conductivity wire-screen (stainless steel) as the interstitial insulation material. Both the inner and outer surface temperatures of the coaxial pipes were measured in order to evaluate the effective thermal conductivity and thermal diffusivity of the insulation concept. The predicted results from the model compared very favorably with the experimental results, confirming both the trends and magnitudes of the experimental data. In other words, whether the reduction in heat transfer observed for small laboratory samples was realistic for application to a pipeline configuration. This effort involved both analytical modeling for all thermal resistances and experimental test runs for validation of the analytical model.

Finally, it was a goal of this investigation to develop a simplified model for a multilayer composite structure which will include radiation heat transfer exchange among the layers that constitute the insulation. With the developed model, feasibility and performance characteristics of the insulation concept were predicted. The thermal predictions have demonstrated the thermal competitiveness of the interstitial insulation technology.