FEATURES OF CALCULATION OF ON-BOARD HEAT EXCHANGERS

Abstract

Aspects of designing an onboard heat exchangers for the cooling system of the ship's power plant are considered. Such heat exchangers must be designed in accordance with the classical foundations of the theory and calculation of heat exchangers. At the same time, the key design points are considered by well-known sources in a separate setting related to the peculiarities of their consideration as specific elements of the theory. In this regard, they are not united by a single system necessary for their use in specific design problems. Accordingly, the paper highlights, concretizes and refines the parameters of the formulas used in the computational problem. In particular, the calculation of the heat transfer coefficient from the seawater side is performed according to the formula that gives the average value of the coefficient for the vessel. The heat transfer coefficients from the side of the coolant of the inner loop are calculated according to the well-known formulas recommended for calculating heat transfer in channels of any shape. Attention is drawn to the fact that heat transfer from the hold side goes to the finned wall. In this regard, the heat transfer coefficients determined by the indicated formulas should be considered convective. The transition to the given values of the heat transfer coefficients should be carried out considering the efficiency of the finned heat exchange surface, which considers the uneven temperature of various sections of the heat exchange surface. The calculation of heat transfer was carried out considering possible surface contamination. The procedure for performing the calculation steps is proposed, as a result of which the dimensions and heat engineering parameters of the heat exchanger can be determined. It was found that the use of the considered proposals leads to results close to those recommended by authoritative sources. The above proposals do not contradict the experience of creating and designing such structures. The recommendations can be used for educational and practical purposes by those who design heat exchangers of similar designs.