Thermoacoustic Cooler Research Articles

The performance of an optimized thermoacoustic air conditioner

Up to 25 thermoacoustic cooler design parameters were optimized to provide high COP predictions in selected air conditioning applications. Capacities ranging between 300 and 1500 W were considered. Two different configurations were investigated: (1) a single stack with a Helmholtz resonator termination, and (2) two drivers and two stacks. The optimization scheme utilized the Simplex algorithm, and the analysis was performed by DELTAE coupled with an original heat exchanger modeling tool which incorporated conventional straight fin analysis and semiempirical flow correlations. Various requirements were imposed for the external cooling and heat rejection temperatures, ranging between 270 and 287 K on the cold side and between 310 and 320 K on the hot side. Finned tube heat exchangers with water as the secondary fluid were considered. The predicted values of COP were greater than 3.8 (0.36, relative to the Carnot value) for an application analogous to a small window air conditioner. The performance and characteristics of the two different configurations were compared, and the loss distribution in each case was calculated. Furthermore, the impact of various constraints was examined. The performance predictions are encouraging and suggest that thermoacoustic air conditioning may be a viable proposition.

Shipboard electronics thermoacoustic cooler

A thermoacoustic refrigerator that was optimized for preservation of biological samples in space, was modified for use as a cooler for the CV-2095 shipboard radar electronics rack. The thermoacoustic cooler was tested in the laboratory and demonstrated at sea aboard USS DEYO (DD-989). In the laboratory, using a calibrated heat load, the data acquisition system was able to account for the total energy balance to within 4%. At the highest operating power aboard ship, 227 W of acoustic power was used to provide 419 W of useful cooling power, corresponding to a coefficient of performance of 1.85. Taking into account the 54% electroacoustic efficiency of the loudspeakers, the shipboard electronics thermoacoustic cooler (SETAC) provided 1 W of cooling for each watt of electrical power input. [Work supported the Office of Naval Research and the Navy Science Assistance Program.]

Shipboard electronics thermoacoustic cooler

A thermoacoustic refrigerator that was optimized for preservation of biological samples in space, was modified for use as a cooler for the CV‐2095 shipboard radar electronics rack. The thermoacoustic cooler was tested in the laboratory and demonstrated at sea aboard USS DEYO (DD‐989). In the laboratory, using a calibrated heat load, the data acquisition system was able to account for the total energy balance to within 4%. At the highest operating power aboard ship, 227 W of acoustic power was used to provide 419 W of useful cooling power, corresponding to a coefficient of performance of 1.85. Taking into account the 54% electroacoustic efficiency of the loudspeakers, the shipboard electronics thermoacoustic cooler (SETAC) provided 1 W of cooling for each watt of electrical power input. [Work supported the Office of Naval Research and the Navy Science Assistance Program.]

Thermoacoustic oscillations in cryogenics. Part 2: applications

Whereas some experimental and theoretical work has been carried out on the basic understanding and damping of thermoacoustic oscillations, very little knowledge is available on technical uses. In part 1 of this paper, a complete model for the design of thermoacoustic engines was presented and experimentally verified with a semi-technical device. In this part, we discuss different possibilities of applications, including an electric generator, a cold compressor, thermoacoustic coolers and a drive for a pulse tube refrigerator. The discussions show that all of these applications are possible. They have some advantages and disadvantages in common, e.g. simplicity with few moving parts, moderate power density and delicate design. These engines have some potential to find applications for special uses, but for most cases, they are not likely to replace the classical devices.