Xhpe
Xhpe models hairpin heat exchangers. A fully incremental program, Xhpe contains HTRI’s latest pointwise methods for predicting condensing, boiling, and single-phase heat transfer and pressure drop. The methods are based on extensive shellside and tubeside condensation, boiling, and single-phase data.
Process Specifications
Xhpe handles the following process conditions:
- single-phase
- vertical and horizontal shell orientations
- shellside and tubeside
- condensation
- shellside and tubeside
- pure fluids and multicomponent mixtures
- superheated, saturated, or partially condensed at inlets
- subcooled, or partially or totally condensed at outlets
- boiling
- horizontal units
- shellside and tubeside
- pure fluids and multicomponent mixtures
- subcooled, saturated, or partially vaporized at inlets
- superheated, or partially or totally vaporized at outlets
Geometry Specifications
Xhpe accommodates the following geometries:
- horizontal and vertical shells
- piping for horizontal thermosiphons
- one to sixteen tubepasses
- plain or longitudinally finned tubes in fixed tubesheet with or without twisted-tape inserts
- unbaffled, segmental, double-segmental, segmental with no-tubes-in-window (NTIW) baffles
All details of the shell construction can be entered. Default values based on TEMA standards and common industrial practice are available.
Calculation Modes
Xhpe operates in rating, simulation, and design modes, automatically screening all cases for flow-induced mechanical and acoustic vibration problems.
Rating
You define exchanger geometry and specify process conditions. Xhpe calculates the expected heat transfer coefficients and pressure drops, compares these calculations to the required heat duty, and reports the difference as under- or overdesign.
Simulation
You define exchanger geometry and specify partial process conditions. Xhpe calculates expected exchanger performance and missing process conditions for zero overdesign, as well as heat transfer coefficients, pressure drops, and heat duty.
Design
Xhpe contains two distinct design options: program and user-specified.
In the program (or classic) mode, you define partial exchanger geometry and enough process conditions for Xhpe to calculate the required heat duty. Xhpe designs missing geometry and calculates expected heat transfer coefficients and pressure drops.
In the user-specified (or grid) design mode, you have complete control over which geometry is varied and over what range each geometric parameter is varied. Xhpe runs all possible permutations and automatically selects the best available design. The component can set the shell style, shell diameter, tube length, tubepasses, baffle spacing, baffle style, tube diameter, and tube pitch.
Calculation Methods
Xhpe employs HTRI’s latest research in a 3D incrementation scheme to model hairpin heat exchangers. The geometry (shell style, baffle spacing, tubepasses, baffle style) divides the exchanger into small increments containing crossflow or window flow and a single tubepass. Localized methods and fluid properties are used to predict the heat transfer and pressure drop in each increment. Incremental techniques allow accurate prediction of shell-and-tube heat exchangers with complex geometry and hydraulics.
Special Features
- Integrated graphical tube layout tool
- Automatic and user-specified design modes