Porous Construction Element PCM Infiltration
Solution Overview
Problem
Current processes for incorporating phase change materials (PCMs) into construction materials face challenges such as interference with cement hydration, reduction of mechanical properties, and issues with uniformity and strength of the composite materials.
Innovation Solution
A process involving the infiltration of a pre-existing porous construction element with a liquid phase change material (PCM) under subatmospheric pressure, allowing the PCM to fill the porosity of the element and form a composite construction element with enhanced thermal properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If PCMs are incorporated into construction materials through macroencapsulation or microencapsulation processes, then thermal inertia is improved, but mechanical strength and durability are reduced
Solution Approach 1:
The construction element is pre-formed with controlled porosity before PCM infiltration, ensuring mechanical strength is established through proper curing and hydration of cementitious materials. The porosity is deliberately designed to provide pathways for PCM infiltration without compromising the structural integrity of the base material.
Solution Approach 2:
The porous structure acts as an intermediary between the PCM and the construction element matrix. It provides a dedicated pathway for PCM infiltration while maintaining the mechanical continuity of the base material, thus preserving strength and durability while enabling thermal energy storage functionality.
2Manufacturing precision
If PCMs are incorporated into construction materials during the mixing process, then uniformity of distribution is improved, but cement hydration is interfered with and mechanical properties are reduced
Solution Approach 1:
The incorporation process is segmented into two distinct stages: (1) formation of the construction element with controlled porosity through cementitious material processing, and (2) subsequent infiltration of PCM into the pre-formed porous structure. This segmentation prevents PCM from interfering with cement hydration while ensuring uniform distribution through capillary action and pressure-driven infiltration.
Solution Approach 2:
The porous structure is preliminarily formed through cementitious material processing before PCM infiltration. This preliminary action allows the cement hydration process to complete without interference from PCM, ensuring proper mechanical property development, while the resulting porosity provides uniform distribution pathways for the PCM.
3Quantity of substance
If porous aggregates are used to include PCM, then thermal energy storage capacity is improved, but bond strength between aggregates and matrix is reduced
Solution Approach 1:
The construction element incorporates a porous structure with controlled pore size, distribution, and connectivity. The porosity is optimized to provide sufficient capacity for PCM infiltration and thermal energy storage while maintaining adequate bond strength through proper aggregate selection, surface treatment, and matrix composition that ensures strong interfacial bonding.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The process results in construction elements with improved thermal inertia, reduced porosity, and increased mechanical strength, effectively addressing the limitations of previous methods while enhancing the thermal performance and durability of the materials.
Implementation Method 1
infiltrating the liquid PCM into the porosity of the pre-existing construction element while the pre-existing construction element and the liquid PCM are at a subatmospheric pressure level
Implementation Method 2
these materials utilize the extra heat produced by an increase in ambient temperature to change phase (from a solid to a liquid, or from a liquid to a gas), absorbing the thermal energy and then releasing it when the ambient temperature decreases and the PCM returns to its original phase
Implementation Method 3
PCMs store thermal energy and release it when the material undergoes a phase change
Implementation Method 4
The process results in construction elements with improved thermal inertia, reduced porosity, and increased mechanical strength
Data Source
AI summary
Processes for incorporating phase change materials (PCM) into porous construction elements, composite construction elements produced thereby, and structures constructed therefrom. Such a process includes heating a PCM to a temperature at or above a melting temperature thereof to liquify the PCM and yield a liquid PCM, fully immersing a porous construction element in the liquid PCM, and infiltrating the liquid PCM into porosity of the construction element while the construction element and liquid PCM are at a subatmospheric pressure level and at a temperature sufficient to maintain the PCM in a liquid state to yield a composite construction element in which the porosity of the construction element has been at least partially filled with the PCM. Such a composite construction element is preferably capable of increasing the thermal inertia of a building envelope constructed therefrom with little or no detrimental effects on properties of the construction elements.