A compromise between the temperature difference and performance in a standing wave thermoacoustic refrigerator

Abstract

Thermoacoustic refrigeration is an evolving cooling technology where the acoustic power is used to pump heat. The operating conditions and geometric parameters are important for the thermoacoustic refrigerator performance, as they affect both its performance and the temperature difference across the stack. This paper investigates the effect of the stack geometric parameters and operating conditions on the performance of a standing wave thermoacoustic refrigerator and the temperature difference across the stack. DeltaEC software is used to make the thermoacoustic refrigerator model. From the obtained results, normalised values for the operating conditions and geometric parameters are collected to compromise both the performance and the temperature difference across the stack.

Thermoacoustic Energy Conversion Devices: Novel Insights

“…Consequently, the resonance frequency is observed to increase as shown in Figure 6 for the obtained resonance frequency at different normalized stack positions through the resonator. 2.4 Amplitude Pressure Figure 7 shows how amplitude pressure affects the temperature difference and performance in a thermoacoustic refrigerator [55]. The temperature difference begins with a low value at the first part of the curve shown in Figure 7(a) due to the weakness of pressure amplitude to make the change, then the increase of amplitude pressure increases the temperature difference until it reaches a maximum value that can be obtained by the increase of this value near a drive ratio of 3 %, after that the non-linear effects takes place.…”

“…The maximum temperature difference occurs at a drive ratio equals 3%, but we are also concerned with Coefficient of performance. A drive ratio equals 2 % was chosen by Alamir and Elamir [55] to improve the Coefficient of performance and to account for the driver abilities to provide this drive ratio.…”

“…The fins of the heat exchanger that is longer than this displacement value do not exploit the additional length of the fin, so design restrictions of the two used heat exchangers are presented [1]. Many factors can affect heat transfer coefficients such as variability of the temperature difference, which vary considerably across the resonator as shown in Figure 8 [55].…”

“…However, problems are found with these optimisation algorithms. For example, they could disregard optimising important operating conditions such as the resonance frequency and not compromise temperature difference and performance [54,55]. Other problems include the theoretical background used as the basic linear theory equations developed shown in Eq.…”

Thermoacoustic Refrigerators and Heat Pumps: New Insights for A High Performance

“…However, problems can be found with these optimization algorithms. For example, they could disregard optimising important operating conditions such as the resonance frequency and not compromise temperature difference and performance [5][6][7][8]. Other problems include the theoretical background used as the basic linear theory equations developed and are usually used incorrectly.…”