Dynamic Data Reconciliation in a Hot-oil Heat Exchanger for Validating Energy Consumption

• Main Authors: P. Singhmaneeskulchai, N. Angsutorn, K. Siemanond
• Format: Article
• Language: English
• Published: AIDIC Servizi S.r.l. 2013-09-01
• Series: Chemical Engineering Transactions
• Online Access: https://www.cetjournal.it/index.php/cet/article/view/6031

Measured data from instruments are usually composed of errors. Data reconciliation is applied to improve the accuracy of measured data to satisfy mass and energy balances of the process. This work is focused on dynamic data reconciliation of a utility heat exchanger using hot oil from a waste heat recovery unit as a hot stream to heat up ethane product as a cold process stream from a natural gas separation plant. The measured data include flow rates, supply and target temperatures of hot oil and cold process streams. The dynamic data reconciliation was done by a combined optimization and constraint model solution strategy by converting the differential equations of the unsteady state equations to the algebraic equations using Euler’s approximation. Adjustment of the hot oil flow rate of the fixed-area utility exchanger leads to a change in the target temperatures of the hot oil and cold process streams, as well as energy consumption. Excel’s solver and commercial optimization software, General Algebraic Modelling System (GAMS), with a weighted least- square objective function are used for performing data reconciliation to validate the measured data and energy consumption. After data reconciliation was completed, estimates of process variables are more accurate and satisfy the process constraints.