Thermoacoustic Stirling power generation from LNG cold energy and low-temperature waste heat

Abstract

Recovering the cold energy generated in the regasification process of liquefied natural gas (LNG) can help to improve the energy efficiency of LNG power generation systems, meanwhile, abundant low-grade waste heat can also be exploited from the exhaust gas of gas turbines. This study proposes to apply the thermoacoustic Stirling electric generator to recover LNG cold energy and waste heat simultaneously. A pair of linear alternators is directly coupled with the thermoacoustic loop by replacing the long and bulky resonator completely. Numerical simulation is conducted on the basis of the thermoacoustic theory to characterize and optimize the operations of the system. The effects of the back volumes of linear alternators, feedback tube length and regenerator length on the output performances are investigated. The distributions of key parameters, including pressure, volume flow rate, phase difference, acoustic power and exergy flow, are further studied. One design of the thermoacoustic Stirling electric generator operated with 4 MPa helium gas is capable of generating 2.3 kW electric power with the highest exergy efficiency of 0.253 when the cold and hot ends are mantained at 110 K and 500 K. Performances can be further improved if the conversion efficiency of the linear alternators is further increased.

The Prospective Non-Conventional Alternate and Renewable Energy Sources in Pakistan—A Focus on Biomass Energy for Power Generation, Transportation, and Industrial Fuel

“…Consequently, a tremendous volume of poultry waste is left over [121,122]. Organic matter from poultry waste is not consumed in any productive way, and is usually pronounced as waste [123], but in reality, it is an advantageous source of energy with vast applications [124][125][126][127]. Biogas generation can be carried out with organic matter such as feathers, blood, manure, and spilled feed, which can be utilized for electricity generation [128,129].…”

Design of a traveling wave thermo‐acoustic engine based on genetic algorithm

“…12,13 Other categories of dynamic Stirling engines are known as Fluidyne and free piston Stirling engines, which are not within the scope of this article. [19][20][21][22][23][24] In addition, they are self-starting, while this latest issue is a challenge in other dynamic Stirling engines, ie, the free piston Stirling engines. In standingwave thermo-acoustic engines, self-sustained oscillating pressure waves are first generated using the applied heat and then are converted into electricity through reversed acoustical speakers.…”

“…9,18 The traveling wave TASEs possess numerous advantages such as being environmentally friendly, low manufacturing cost, long operating life, and high thermal efficiency. [19][20][21][22][23][24] In addition, they are self-starting, while this latest issue is a challenge in other dynamic Stirling engines, ie, the free piston Stirling engines. [25][26][27][28] Indeed, the conventional engines require a starter (eg, an electric motor) to run.…”

Review on recent liquefied natural gas cold energy utilization in power generation cycles

“…Wang thermoacoustic Stirling electricity generator ( Wang, et al, 2017) for dual-utilizations of LNG cold energy and low-grade waste heat. As reported, the optimized system was able to reach an output electric power of 2.3 kW with the highest exergy efficiency of 0.253 at 4 MPa helium gas.…”