Heating assemblies, heat exchange assemblies, methods for providing and/or exchanging heat, turbine combustion engines, and methods for powering turbine combustion engines
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Solution Overview
Problem
The high cost and large size of heat exchangers in supercritical CO2 power cycles, particularly at high temperatures, hinder efficiency and cost savings due to the low convective heat transfer coefficient of scCO2, which requires larger and more expensive heat exchangers, and existing solutions have not adequately addressed the size and cost reduction.
Innovation Solution
The implementation of heat exchanger assemblies with selective thermal emission coatings that radiate light predominantly between 4 and 4.5 μm, where CO2 absorption is maximal, allowing for reduced heat exchanger size by up to 45% through enhanced radiative heat transfer, using materials like Si, Ag, Cr, Au, and refractory metals, and photonic crystal motifs to achieve high emissivity and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional heat exchanger designs are used for supercritical CO2, then heat transfer can be achieved, but the heat exchanger size becomes excessively large and cost exceeds 50% of plant capital budget
Solution Approach 1:
The invention changes the physical parameters of the heat exchanger surfaces by applying selective thermal emission coatings that radiate light predominantly between 4 and 4.5 μm wavelengths, where CO2 absorption is maximal. This parameter change in radiative heat transfer characteristics enables significantly reduced heat exchanger size while maintaining effective heat transfer to supercritical CO2
Solution Approach 2:
The invention uses composite material structures including selective emitter layers (such as Si, Ag, Cr, Au, or refractory metals) applied to heat-sinking substrates. These composite coatings combine materials with specific thermal and optical properties to maximize radiative heat transfer efficiency at the target wavelength range, resolving the contradiction between heat transfer effectiveness and heat exchanger size
2Volume of stationary object
If heat exchanger size is reduced to lower cost, then capital cost decreases, but heat transfer effectiveness deteriorates due to low convective heat transfer coefficient of scCO2
Solution Approach 1:
The invention substitutes convective heat transfer mechanisms with radiative heat transfer mechanisms by implementing selective thermal emission coatings. This replacement of the dominant heat transfer mode enables effective heat transfer at much smaller heat exchanger sizes, overcoming the limitation of low convective heat transfer coefficients of supercritical CO2
Solution Approach 2:
By changing the thermal radiation parameters of the heat exchanger surfaces through selective coatings tuned to 4-4.5 μm wavelengths, the invention maximizes radiative heat transfer efficiency. This parameter change compensates for the reduced heat transfer surface area, maintaining heat transfer effectiveness while reducing heat exchanger size
3Temperature
If thermal barrier coatings are applied to turbine blades, then blade temperature protection is improved, but heat is lost to the environment through air cooling behind the blades, reducing turbine efficiency
Solution Approach 1:
The invention changes the thermal radiation properties of turbine blade coatings by implementing selective emitter layers that radiate predominantly at 4-4.5 μm wavelengths. This parameter change in spectral emission characteristics allows the blades to radiate heat back into the combustion products at temperatures where CO2 absorption is maximal, converting what would be waste heat loss into useful heat transfer that increases turbine power output by 6%
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 selective thermal emission coatings significantly reduce heat exchanger size and cost while enhancing thermal efficiency, achieving a 6% increase in turbine power output and improved thermal management in gas turbines by maximizing radiative heat transfer to scCO2 and CO2 in combustion gases.
Implementation Method 1
the layer configured to provide photons of a predefined wavelength upon receiving heat from the substrate
Implementation Method 2
enhanced radiative heat transfer
Implementation Method 3
where CO2 absorption is maximal
Data Source
AI summary
Heat exchanger assemblies and methods for providing heat exchange as well as methods providing specific energy to predetermined materials within an assembly as well as gas turbine engines as well as methods of powering same are provided. Heating assemblies are provided that can include: a heat-sinking substrate; and a selective emitter layer in thermal communication with the substrate. These assemblies can be provided as part of heat exchanger assemblies. Methods for providing heat to a fluid are also provided that can include heating a layer upon a substrate to provide photons of a predetermined wavelength to a fluid from the layer.Turbine combustion engines are also provided that can include a turbine having at least a portion of the blades in the hot section of the turbine coated with an emissivity layer in thermal communication with the turbine blade. Methods for powering turbine combustion engines are also provided.