This article identifies and describes five alternative cooling technologies (magnetic, thermionic, thermoacoustic, thermoelectric, and thermotunnel) and qualitatively assesses the prospects of each technology relative to vapor compression for space cooling and food refrigeration applications. Assessment of the alternatives was based on the theoretical maximum percent of Carnot efficiency, the current state of development, the best percent of Carnot efficiency currently achieved, developmental barriers, and the extent of development activity. The prospect for each alternative was assigned an overall qualitative rating based on the subjective, composite view of the five characteristics.

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The Prospects of Alternatives to Vapor Compression Technology for Space Cooling and Food Refrigeration Applications

Pulse tube refrigerator with elastic air reservoir

Study of a gas-liquid-coupled heat-driven room-temperature thermoacoustic refrigerator with different working gases

Numerical studies of co-axial travelling-wave thermoacoustic cooler powered by standing-wave thermoacoustic engine

The invention provides an acoustic resonance type traveling wave thermo-acoustic power generating system. The acoustic resonance type traveling wave thermo-acoustic power generating system is composed of at least three acoustic resonance type traveling wave thermo-acoustic engines, at least one linear motor and resonation tubes. The acoustic resonance type traveling wave thermo-acoustic engines are connected through the resonation tubes in an end-to-end mode to form a loop. Each thermo-acoustic engine unit comprises a main indoor temperature heat exchanger, a heat regenerator, a hot end heat exchanger, a heat buffer tube, a secondary indoor temperature end heat exchanger, one resonation tube and a loop direct-current suppressor. Each linear motor is connected to the corresponding resonation tube and located besides the resonation tube. Compared with the prior art, the acoustic resonance type traveling wave thermo-acoustic power generating system can convert heat energy of different grades into electric energy and has the advantages of being good in reliability, high in efficiency, flexible in power and the like. The acoustic resonance type traveling wave thermo-acoustic power generating system can be applied to the solar energy utilization field, the biomass energy utilization field, the industrial waste heat utilization field and the like and is high in practical value and good in application prospect.

Acoustic resonance type traveling wave thermo-acoustic power generating system

The invention discloses a fluctuation thermoacoustic generation system, which comprises the following loop parts in sequence: cold junction heat exchanger, heat regenerator, heater, heat buffer pipe, hot junction heat exchanger, ring-shaped connection pipe and line generator in the pipe, wherein the generator contains a cylinder with one end of casing on the pipe and the other end with line sliding bearing; a double-loop magnetic-inductive soft iron with ring orifice is set in the cavity between cylinder and casing; the permanent magnet is inserted in the outer ring magnetic wall of soft iron; the coil rack is fixed on cylinder inner wall with part of coil in the ring orifice; the elastic or quality component is set in the hot junction pipe; the quality component does shift sliding along the elastic element; the elastic or quality phase modulation component is set in the greenhouse pipe; the quality component does shift sliding along the elastic phase modulation element. The invention can adjust the phase difference of pressure fluctuation and bulk flow fluctuation, which feedbacks the acoustic power to accomplish high effective Stirling cycle as well as inhibits the loop ring current to improve property of entire machine.

Electricity generating system driven by traveling wave thermoacoustic engine

The invention provides a thermo-acoustic engine system by adopting variable-temperature heat source. The system comprises a resonant tube. The resonant tube is provided with a mechanical energy output device and at least two stages of traveling wave loops; all the traveling wave loops share the resonant tube; each traveling wave loop is provided with a high-temperature heat exchanger; the high-temperature heat exchanger is provided with an input port and an output port used as the input and output medium; the output port of the high-temperature heat exchanger of the previous traveling wave loop communicates with the input port of the high-temperature heat exchanger of the next traveling wave loop, and the working temperature of the high-temperature heat exchangers of the at least two stages of traveling wave loops gradually reduce from the previous traveling wave loop to the next traveling wave loop. The system improves the heat conversion efficiency and has compact structure.

Thermo-acoustic engine system using temperature-variable heat source

The invention provides a thermo-acoustic liquid state magnetic fluid alternative electric generation system which comprises a thermo-acoustic motor and a liquid state magnetic fluid alternating current ganerator, the resonatron of the thermo-acoustic motor is coupled on one opening end of the pipe of the liquid state magnetic fluid alternating current ganerator for containing the liquid state magnetic fluid, the pipe is arranged in the magnetic field to make the liquid state magnetic fluid cut the magnetic force line to generate electric energy when flowing in the pipe, the pipe comprises an output electrode for outputing the generated electric energy, which is characterized in that, the working substance of the thermo-acoustic motor is gas working substance. The invention reduces manufacturing difficulty and cost of the prior electric generation system, and the working frequency is suitable, the efficiency is high.

Sound-heat liquid magnetofluid AC generating system

A refrigeration low-temperature system of heat sound magnetic includes a feedback tube (1), a elastic membrane (7), a room temperature terminal heat-exchange facility (2), a heat regenerator (3), a heat regenerator (4), a heat buffer tube (5), a room temperature terminal heat-exchange facility (6), a resonating tube (8) at the three-way, and also includes a pulse-tube refrigerator jointing to the resonating tube (8) by branch path form and a magnetic refractor jointing to the resonating tube (8) by branch path form, two refractor system is placed in the vacuum hood (32) with high vacuum.

Heat voice magnetic refrigeration low temperature system

The present invention discloses a hot-wire anemometer calibrating device in a sound filed and a calibrating method. The device comprises the following components: a closed container; a driving mechanism which is fixed and installed in the closed container; a probe which is connected with the driving mechanism and moves under the driving of the driving mechanism; a displacement transducer which is provided on the driving mechanism; a pressure sensor and a temperature sensor which are installed at the inner part of the container; and a conducting wire. The method comprises the following procedures: when the closed container is executed with vacuum pumping, filling a working medium to be tested; setting a first group of working condition point; setting a second group of working condition point; respectively collecting a hot-wire electric signal corresponding with the working condition point to the first group of working condition point and the second working condition point; respectively executing data fitting to the first group of working condition point, the second group of working condition point and the corresponding hot-wire electric signals; and fitting the two obtained data and then executing combination fitting. The calibrating to the hot-wire anemometer is more accurate and a larger speed range can be calibrated.

Wei Dai

Papers

Electricity generating system driven by traveling wave thermoacoustic engine

Thermo-acoustic engine system using temperature-variable heat source

Sound-heat liquid magnetofluid AC generating system

Heat voice magnetic refrigeration low temperature system

Hot-wire anemometer calibration apparatus and method in acoustic field