Analytical Solution of the Transient Response of Gas-to-Gas Crossflow Heat Exchanger With Both Fluids Unmixed

Abstract

The dynamic response of a single-pass crossflow heat exchanger with both fluids unmixed to arbitrary time varying inlet temperatures of fluids is investigated analytically. The initial spatial temperature distribution of the heat exchanger core is arbitrary as well. Analytical solutions for temperature distributions of both fluids and the wall as well as the mean mixed fluid temperatures at the exit are presented. The solutions are found by using Laplace transform method and special functions in the form of series of modified Bessel functions.

Experimental prediction of heat transfer coefficients by use of a double-blow method

“…At zero time, begins the heating of fluid 1 by electrical heater producing exponential change of temperature. In all necessary theoretical details, this system was discussed in [3] where the mean mixed outlet temperatures are given in the explicit analytical form.…”

Dynamic response and control analysis of cross flow heat exchangers under variable temperature and flow rate conditions

“…A step variation to the inlet fluid temperature of either the hot side or the cold side was considered. Gvozdenac [8] and Spiga and Spiga [9] extended the work and investigated the transient behavior of gas-to-gas cross flow heat exchangers in the case of step change [8] and arbitrary inlet temperature variations, such as step, ramp, and exponential input functions [9]. In their work, two or three-fold Laplace transform techniques are used to solve the energy balance equations to achieve the temperature response.…”

Dynamic Analysis of Cross Flow Heat Exchangers in Data Centers Using Transient Effectiveness Method

“…A few years later, Romie [12] predicted the average outlet temperature response of gas-to-gas cross flow heat exchangers using a double Laplace transform technique under step change to the inlet temperature of either the hot side or the cold side of fluid. Gvozdenac [13], and Spiga and Spiga [14] extended the work and investigated the transient behavior of gas-to-gas cross flow heat exchangers under arbitrary inlet temperature variations, such as step, ramp, and exponential input functions. In [13] and [14], the energy balance equations are solved using both two-fold and three-fold Laplace transform techniques.…”

“…Gvozdenac [13], and Spiga and Spiga [14] extended the work and investigated the transient behavior of gas-to-gas cross flow heat exchangers under arbitrary inlet temperature variations, such as step, ramp, and exponential input functions. In [13] and [14], the energy balance equations are solved using both two-fold and three-fold Laplace transform techniques. It is progressively more difficult to invert the transformed temperatures at the wall and the two fluids in the physical domain using this technique.…”