• Energy Research

Engine Health Monitoring (EHM) systems are becoming essential parts of modern aircraft engines to enhance safe and long operation and to reduce down time. Activities initiated to develop EHM for a typical aero engine under NPMASS sponsored project. It is planned to acquire detailed gas path data to evaluate engine performance parameters more accurately. This requires additional sensors to be incorporated in the engine gas path along with the available sensors already mounted by the manufacturer. Consequently, an assignment has been taken under EHM program to mount additional sensors in a typical aero engine with active participation from HAL / RCMA, Koraput. The design, fabrication, assembly and testing of several pressure sensing adaptors and temperature sensors have been discussed in detail in this report. The mechanical design of adaptors / sensors has been made to meet the requirements of high temperature and vibration environment during all the ratings of the engine test. The preliminary trial test for the fabricated sensor components has been carried out in the engine test bed. Satisfactory results of the components have been observed during trial tests.

High supercooling and single functionalization are the main barriers to the large-scale application of microencapsulated phase-change materials (PCMs) in the construction industry. To address these issues, we propose a new inorganic microencapsulated PCM, PW@CaWO4, which was synthesized via the in situ polymerization method using inorganic CaWO4 as shell and phase-change paraffin wax (PW) as core. We investigated the effects of different emulsifiers and core-to-shell ratios on microcapsule properties and found that the PW@CaWO4 microcapsules have regular spherical topography and good uniformity in particle size. During the synthesis process, the CaWO4 shell provides convenient conditions for heterogeneous nucleation of PW and effectively reduces the supercooling degree. The minimum supercooling degree of the PW@CaWO4 microcapsules is only 1.00 ± 0.08 °C, which is 3.41 °C lower than that of PW. Moreover, the PW@CaWO4 microcapsules can absorb ultraviolet radiation and exhibit fluorescence, which originates from the peculiar WO42– structure in the CaWO4 shell, eliminating the need for doping other light-activating ions into the shell. The newly prepared microcapsules possess several advantages, including suitable particle size, low supercooling, good heat storage, high thermal conductivity, good short-wave ultraviolet absorption, peculiar fluorescence, excellent proof of leakage, and so on. The microcapsules can be applied to fluorescent architectural energy-saving coatings.

Solar thermal power plants are a key technology for electricity generation from renewable energy resources. Thermal energy storage (TES) systems correct the mismatch between the solar supply and the power demand. TES makes it possible to meet the intermediate load profile with dispatchable power, a benefit that has a high value to power utilities and that gives concentrating solar power (CSP) technology an edge over photovoltaic and wind power. Hence, TES is a key technology for solar thermal energy utilization with growing present and future importance. This chapter focuses on material aspects of alkali nitrate salts. They include thermal properties, thermal decomposition processes, steel corrosion issues, and phase diagrams of multicomponent salt systems. In addition, two CSP applications using molten nitrate salts as sensible and latent TES are discussed.