Optimization of the operating parameters of the condenser of a pyrolysis bioenergy plant for the processing of agricultural waste

This paper presents a study aimed at optimizing the operating parameters of the condenser of a pyrolysis bioenergy plant designed for thermal processing of biomass. Given the importance of effective condensation of the vapor-gas mixture coming from the reactor of the unit, special attention is paid to modeling heat transfer in a spiral coil taking into account the phase transition. A physical and mathematical model based on the energy balance, the Clausius– Clapeyron equation and the logarithmic temperature head in the countercurrent scheme has been developed. Multi-purpose Bayesian optimization is used as a solution method, which makes it possible to find a compromise between the maximum heat flux and the minimum cooling water flow. As a result of the numerical experiment, the optimal value of the mass flow rate of cooling water (≈0.03 kg/s) was determined, at which the maximum heat flux (≈4389 W) is achieved. The results obtained confirm the effectiveness of the proposed approach and substantiate its applicability in the tasks of improving the energy efficiency of small-scale pyrolysis bioenergy plants. The presented methodological and calculation solutions can be used in engineering practice in the design of heat engineering equipment for the processing of agricultural and wood biomass.