Standing wave gas-liquid phase change thermoacoustic engine driven by low-grade heat source

Abstract

The invention discloses a low-grade heat source driven standing wave type gas and liquid phase change thermoacoustic engine. The thermoacoustic engine comprises a first heater, a first thermal buffering pipe, a first cooler, a U-shaped pipe, a second cooler, a second thermal buffering pipe and a second heater which are connected sequentially, wherein a liquid piston is arranged in the U-shaped pipe. The thermoacoustic exchange is realized based on a gas and liquid phase change thermoacoustic effect, and the ideal thermodynamic cycle can be approximately two isobaric processes and two adiabatic processes. Compared with the conventional gas medium thermoacoustic engine system, the thermoacoustic engine has the characteristics that the temperature difference of cold and heat sources is low, the thermoacoustic engine can run in small temperature difference and at a large pressure ratio, and the low-grade heat source can be utilized; the energy density of unit volume is high, so that the system can be miniaturized; and the gas and liquid coupled oscillation can be realized, and the acoustic impedance of the thermoacoustic engine system can be optimized by comprehensively utilizing the compressibility of gaseous medium, and the high-density mass inertia of the liquid medium.

Description

technical field [0001] The invention relates to a heat engine device, in particular to a thermoacoustic engine driven by a low-grade heat source. Background technique [0002] The thermoacoustic engine is also called a thermoacoustic compressor, or a thermoacoustic driver. It is only composed of a heat exchanger and a pipe section. It has no mechanical moving parts except for the alternating fluid working fluid. Therefore, it has a simple structure, stable and reliable operation, and a long life. Longevity and other characteristics have attracted the attention of academia and industry. [0003] Thermoacoustic engines usually use gas as the working medium, and use the thermal interaction between the gas sound field and the solid boundary in the regenerator (or plate stack) to convert thermal energy into mechanical energy. When the temperature gradient of the device (or plate stack) is greater than the critical value, the gas working medium will produce self-excited oscillati...

AI Technical Summary

Problems solved by technology

[0006] However, analyzing the working mechanism and technical status of the existing gas working fluid thermoacoustic engines, it can be found that they have problems such as the high temperature of the driving heat source (usually higher than 300°C), which makes it difficult to directly use low-grade heat sources, and the relatively small energy density leads to The large volume of the system and other shortcomings limit its practical application, which is an important problem to be solved urgently in the research field of thermoacoustic engines.

Images