The Maisotsenko Open Cycle combines the thermodynamic processes of heat exchange and evaporative cooling in a unique indirect evaporative cooler resulting in product temperatures that approach the dew point temperature, (not the wet bulb temperature) of the working gas. It is an open thermodynamic cycle utilizing several thermodynamic processes that cools a product fluid with a liquid evaporating into a gas, generally water evaporating into air from the atmosphere and returns it to the atmosphere. It is a new cycle as no other cycle can be diagramed in the same way on the psychrometric chart of a gas. In a gas turbine, the gas is air and evaporate is water. An atmospheric pressure heat and mass exchanger operating with the Maisotsenko Cycle can be used to cool compressor inlet air below the wet bulb temperature. In a high-pressure heat and mass exchanger the cycle can create a compressed air saturator using heat from the turbine exhaust gases and also cools water for heat recovery in a compressor inter-cooler. The same saturator will humidify and/or superheat the compressed air before entering a combustor to the amount desired. From a practical stand point the limit of humidification of the compressed air is the amount of heat available at a temperature above its dew point temperature from the exhaust gas and/or intercompressor coolers. The amount of superheating or humidifying of the compressed air is easily controlled and changed during operation allowing added power, or greater efficiency, (60% overall thermal efficiency) quickly and easily. The equipment uses existing shell and tube heat exchanger or plate heat exchangers technologies. There are many other benefits ranging from lower NOx to greatly reduced equipment cost compared to any other power cycle enhancement systems.
Capillary flow of water in an array of open nanotextured microgrooves fabricated by femtosecond laser processing of silicon is studied as a function of temperature using high-speed video recording. In a temperature range of 23–80 °C, the produced wicking material provides extremely fast liquid flow with a maximum velocity of 37 cm/s in the initial spreading stage prior to visco-inertial regime. The capillary performance of the material enhances with increasing temperature in the inertial, visco-inertial, and partially in Washburn flow regimes. The classic universal Washburn’s regime is observed at all studied temperatures, giving the evidence of its universality at high temperatures as well. The obtained results are of great significance for creating capillary materials for applications in cooling of electronics, energy harvesting, enhancing the critical heat flux of industrial boilers, and Maisotsenko cycle technologies.
A superwicking Ti-6Al-4V alloy material with a hierarchical capillary surface structure was fabricated using femtosecond laser. The basic capillary surface structure is an array of micropillars/microholes. For enhancing its capillary action, the surface of the micropillars/microholes is additionally structured by regular fine microgrooves using a technique of laser-induced periodic surface structures (LIPSS), providing an extremely strong capillary action in a temperature range between 23 °C and 80 °C. Due to strong capillary action, a water drop quickly spreads in the wicking surface structure and forms a thin film over a large surface area, resulting in fast evaporation. The maximum water flow velocity after the acceleration stage is found to be 225–250 mm/s. In contrast to other metallic materials with surface capillarity produced by laser processing, the wicking performance of which quickly degrades with time, the wicking functionality of the material created here is long-lasting. Strong and long-lasting wicking properties make the created material suitable for a large variety of practical applications based on liquid-vapor phase change. Potential significant energy savings in air-conditioning and cooling data centers due to application of the material created here can contribute to mitigation of global warming.
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