Plate Heat Exchanger CFD Simulation by ANSYS Fluent Training

A comprehensive computational fluid dynamics analysis of a 4-layer plate heat exchanger design, demonstrating the thermal-hydraulic performance characteristics and heat transfer mechanisms between alternating hot and cold fluid channels. This simulation provides valuable insights into plate heat exchanger behavior through detailed visualization of temperature distributions, flow patterns, and quantitative performance metrics.

Project Overview

This simulation investigates a 4-layer plate heat exchanger configuration with alternating hot and cold water channels. The model captures the complex fluid flow and heat transfer phenomena occurring within the compact plate arrangement, demonstrating how thermal energy is effectively transferred between the fluid streams through the separating plates.

Key Simulation Parameters

• Configuration: 4-layer plate heat exchanger with alternating hot and cold channels
• Hot Fluid: Water at 286.2K with 0.0045 kg/s mass flow rate
• Cold Fluid: Water at 276.5K with 0.00361 kg/s mass flow rate
• Mesh: Unstructured grid with approximately 2,273,000 elements

Methodology and Approach

Geometric Configuration

The heat exchanger consists of four parallel flow channels arranged in alternating hot and cold layers:

• Layers 1 and 3: Cold fluid channels (heating process)
• Layers 2 and 4: Hot fluid channels (cooling process)
• Defined inlet and outlet regions for each fluid stream
• Solid plates separating fluid channels (not explicitly mentioned but implied)

Simulation Setup

• Solver Configuration: Pressure-based, steady-state simulation
• Turbulence Model: Standard k-epsilon with standard wall functions
• Energy Equation: Enabled for heat transfer analysis
• Discretization Schemes:
  • Momentum: Second-order upwind
  • Energy: Second-order upwind
  • Turbulence parameters: First-order upwind
• Solution Algorithm: SIMPLE pressure-velocity coupling

Boundary Conditions

• Hot Inlet: 286.2K at 0.0045 kg/s with 2% turbulence intensity
• Cold Inlet: 276.5K at 0.00361 kg/s with 2% turbulence intensity
• Hydraulic Diameter: 0.003m for both inlets
• Initialization Parameters: Zero gauge pressure, specified velocity components and turbulence parameters

Results and Analysis

Temperature Distribution

The simulation reveals the thermal behavior across all four layers:

• Progressive temperature change along the flow path in each channel
• Hot fluid cooling from 286.2K to 281.213K
• Cold fluid heating from 276.5K to 282.725K
• Temperature convergence at exits (~282K for both streams)

Flow Characteristics

• Detailed velocity contours showing flow distribution within each layer
• Streamline visualizations demonstrating flow patterns and potential recirculation zones
• Impact of plate geometry on local flow behavior

Heat Transfer Performance

• Quantified heat transfer rate from hot fluid: 93.8503W
• Quantified heat absorption by cold fluid: 93.9754W
• Energy balance verification with less than 0.2% discrepancy
• Thermal effectiveness assessment based on inlet-outlet temperature differences

Engineering Insights

The simulation demonstrates several key aspects of plate heat exchanger performance:

• Effective thermal energy transfer between alternating fluid streams
• Nearly identical exit temperatures despite different inlet conditions
• Balanced heat transfer rates confirming simulation accuracy
• Influence of flow distribution on local heat transfer effectiveness

This analysis provides valuable information for design optimization, performance prediction, and operational parameter selection for plate heat exchangers in various industrial applications including HVAC systems, food processing, and chemical industries.