Modeling and experimental analysis of high-efficiency fluid temperature fluctuation attenuator based on phase regulator

Temperature fluctuation attenuators are important passive components for disturbance rejection in precise temperature control system, but previous attenuator researches mainly focused on increasing effective heat capacity to achieve better attenuation. In this paper, the temperature phase regulator (TPR) model is proposed as a superior method to reduce fluid temperature disturbances with less capacity. It achieves output temperature fluctuation attenuation by shifting the phase of the delay side temperature signal and mixing it with the normal side. Similar to the principle that notch filters can highly attenuate signals in specific frequency bands, we constructed TPR theoretical models under equal flow ratios and non-equal flow ratios. Different bandwidths, attenuation depths and target center frequencies can be achieved by changing the two parameters of equivalent heat capacity and flow ratio, and the mechanism of parameters affecting the TPR amplitude-frequency characteristics was analyzed. In terms of effect evaluation, we verified the correlation between the frequency domain and the time domain data, and compared the TPR with the thermal capacity attenuator and other popular attenuators in terms of MSE, MAE and Max-min of temperature data. In a typical temperature attenuation test, TPR can achieve 40% and 35% of MAE and Max-min value attenuation rates, which are exceeding the ideal upper limit of other attenuators and far superior to typical attenuators. The experimental data confirmed the feasibility of the heat capacity of the pipe to support the TPR delay side as a pure delay. The experimental results of non-equal flow ratios verified the model reference-ability of changing flow ratio. In the equal flow ratio test, the fit of the actual data curve and the theoretical curve showed the accuracy of the theoretical model, and the MAE attenuation ratio better than 70% reflected the excellent attenuation performance.