Disclosed are a thermoacoustic engine with high conversion efficiency from heat energy to acoustic energy and a designing method for the thermoacoustic engine. A stack of the thermoacoustic engine has a plurality of flow passages extending through a thermoacoustic piping section. A hot heat exchanger is coupled to one end in a longitudinal direction of the stack. A cold heat exchanger is coupled to the other end in the longitudinal direction of the stack. And a length in the longitudinal direction of the hot heat exchanger is greater than a length in the longitudinal direction of the stack, and is greater than a length in the longitudinal direction of the cold heat exchanger.

A thermoacoustic device includes a loop tube in which a working gas is sealed; a stack in which a temperature gradient is generated in a tube axis direction of the loop tube, the stack being provided in the loop tube; and a diaphragm structure including a diaphragm provided in the loop tube and an operating unit, the diaphragm having a surface extending in a direction intersecting the tube axis direction and being configured to vibrate with a component of vibration in the tube axis direction, and the operation unit being configured to apply a physical quantity that is required, to the diaphragm to change a rigidity of the diaphragm in the tube axis direction.

A thermoacoustic cooling device includes a tube in which a working fluid is enclosed; a first stack that generates acoustic waves in the working fluid with use of a temperature gradient; a first high-temperature heat exchanger provided at a first side of the first stack to heat the first side of the first stack; a first low-temperature heat exchanger provided at a second side of the first stack; a second stack in which a temperature gradient is generated by the acoustic waves; a second high-temperature heat exchanger provided at a first side of the second stack, which has a high temperature; a second low-temperature heat exchanger provided at a second side of the second stack, which has a low temperature; and a heat transfer portion configured to connect the second low-temperature heat exchanger to the first low-temperature heat exchanger so as to transfer heat therebetween.

An energy conversion device includes a first acoustic wave generator, a second acoustic wave generator, and an output unit which are provided in a pipe member. The first acoustic wave generator has a thermal energy generator configured to generate thermal energy from electric energy, and converts the thermal energy generated by the thermal energy generator into acoustic energy to generate acoustic wave in working gas by a self-excited thermo acoustic vibration. The second acoustic wave generator converts thermal energy supplied from a heat supply source into acoustic energy and generates acoustic wave in working gas by a self-excited thermo acoustic vibration. The output unit converts the acoustic energy of the acoustic waves from the first acoustic wave generator and the second acoustic wave generator into cold energy to output.

In a conveying device, a belt conveyer is equipped with a conveying portion that conveys an object from an upstream region to a downstream region. A heat source heats the conveyed object. A cooling portion is located downstream of a terminal end of the belt conveyor and cools the object. A first thermoacoustic cooling device cools the cooling portion. A first prime mover generates acoustic waves from heat transmitted from the first heat source. A first receiver generates, from the acoustic waves, cooling heat corresponding to a cooling temperature that is lower than a temperature of the heat source.

A thermoacoustic device includes a loop pipe, a first stack that is disposed in the loop pipe and that generates a sound wave in the loop pipe by way of a temperature gradient, a second stack that is disposed in the loop pipe and that generates a temperature gradient, a first high temperature side heat exchanger that is disposed at one end of the first stack and that makes the temperature of the one end of the first stack be higher than the other end, and a first low temperature side heat exchanger that is disposed at the other end of the first stack and that makes the temperature of the other end of the first stack be lower than the one end.

A thermoacoustic refrigerator includes at least one pair of pulse combustion tubes (10), preferably Rijke tubes, each tube (10) having a pair of spaced-apart Stirling engines (12), coupled together but with no separating membrane therebetween.

A thermoacoustic device includes a loop pipe, a first stack that is disposed in the loop pipe and that generates a sound wave in the loop pipe by way of a temperature gradient, a second stack that is disposed in the loop pipe and that generates a temperature gradient, a first high temperature side heat exchanger that is disposed at one end of the first stack and that makes the temperature of the one end of the first stack be higher than the other end, and a first low temperature side heat exchanger that is disposed at the other end of the first stack and that makes the temperature of the other end of the first stack be lower than the one end.

An energy conversion device includes a first acoustic wave generator, a second acoustic wave generator, and an output unit which are provided in a pipe member. The first acoustic wave generator has a thermal energy generator configured to generate thermal energy from electric energy, and converts the thermal energy generated by the thermal energy generator into acoustic energy to generate acoustic wave in working gas by a self-excited thermo acoustic vibration. The second acoustic wave generator converts thermal energy supplied from a heat supply source into acoustic energy and generates acoustic wave in working gas by a self-excited thermo acoustic vibration. The output unit converts the acoustic energy of the acoustic waves from the first acoustic wave generator and the second acoustic wave generator into cold energy to output.

A thermoacoustic heating device capable of effectively utilizing streaming, and including a prime mover in a first pipeline that forms a loop line, and a heating device in a second pipeline that forms another loop line. The first and second pipelines are connected to each other via a branch pipeline. A branch pipeline on the prime mover side and the second pipeline on the heating device side are positioned adjacent to each other, and a low-temperature side heat exchanger of the heating device is integrally formed with or held in contact with the branch pipeline on the prime mover side.