Plate Heat Exchanger CFD Simulation with ANSYS CFX: Conjugated Heat Transfer Analysis

A detailed computational fluid dynamics investigation of a specialized plate heat exchanger design featuring solid plates with corner-mounted flow channels. This simulation leverages ANSYS CFX to capture the complex interplay between convective and conductive heat transfer mechanisms, providing insights into thermal performance characteristics under counter-flow operating conditions.

Heat Exchanger Configuration and Design Parameters

This simulation examines a unique plate heat exchanger configuration consisting of four solid plates with integrated corner pipes, creating a specialized thermal pathway that combines convective heat transfer in fluid channels with conductive heat transfer through solid plates. The 2.5D modeling approach provides comprehensive insights into the thermal-hydraulic behavior of this system.

Geometric Specifications

• Plate Dimensions: 2m × 2m with 0.1m thickness
• Flow Channels: Four corner-mounted pipes with 0.15m diameter and 1.1m length
• Material Configuration: Single-part construction with integrated solid and fluid domains
• Flow Arrangement: Counter-flow configuration with temperature differential of 20°C

Computational Domain

• Mesh Characteristics: Unstructured grid with 5,096,686 elements
• Near-Wall Treatment: Five inflation layers within pipe regions for boundary layer resolution
• Domain Integration: Combined solid-fluid mesh with preserved interface continuity
• Mesh Quality: Enhanced resolution at critical heat transfer interfaces

Simulation Methodology and Physical Models

Conjugated Heat Transfer Approach

• Heat Transfer Mechanisms: Simultaneous modeling of:
  • Convective transport between fluid and pipe walls
  • Conductive diffusion through solid plates
  • Thermal coupling at fluid-solid interfaces
• Energy Formulation: Thermal Energy model for incompressible flow
• Analysis Type: Steady-state simulation with coupled thermal-fluid solution

Numerical Methods and Models

• Turbulence Model: k-epsilon with Scalable Wall Function
• Discretization Scheme: High Resolution Advection Scheme for improved accuracy
• Turbulence Numerics: High Resolution approach for turbulence equations
• Convergence Criteria: Appropriate residual targets for momentum and energy

Operating Conditions

• Working Fluid: Water with temperature-dependent properties
• Flow Parameters: Uniform velocity in all channels
• Temperature Differential: 20°C and 40°C inlet temperatures in opposing flow directions
• Simplifications: Negligible gravitational effects, steady-state conditions

Results and Performance Analysis

Thermal Characteristics

• Temperature Distribution: Visualization of thermal gradients throughout the system
• Heat Transfer Pathways: Identification of primary conduction routes between channels
• Thermal Spreading: Analysis of heat diffusion patterns within solid plates
• Temperature Contours: Clear visualization of isothermal lines across the domain

Flow Behavior

• Pressure Distribution: Characterization of pressure fields in flow channels
• Velocity Patterns: Analysis of flow development in pipe sections
• Turbulence Characteristics: Evaluation of turbulent kinetic energy distribution
• Flow Uniformity: Assessment of flow distribution across parallel channels

Performance Metrics

• Heat Transfer Effectiveness: Evaluation of thermal exchange efficiency
• Temperature Profiles: Analysis of fluid temperature evolution along flow paths
• Pressure Drop: Quantification of hydraulic resistance through the system
• Thermal Gradients: Assessment of temperature differential across solid medium

Engineering Insights

• Design Implications: Guidance for optimizing plate thickness and pipe placement
• Velocity Effects: Confirmation of flow rate impact on convective heat transfer
• Heat Path Optimization: Strategies for enhancing conductive pathways
• System Efficiency: Balance between thermal performance and pressure loss

This comprehensive CFD simulation using ANSYS CFX provides valuable insights into the thermal-hydraulic behavior of this specialized plate heat exchanger design. The results demonstrate the effectiveness of the counter-flow arrangement and the significant role of conduction through the solid plates in facilitating heat transfer between the fluid streams. The high-resolution numerical approach with enhanced boundary layer treatment ensures accurate capture of the convective heat transfer processes, providing reliable guidance for design optimization and performance prediction in similar heat exchanger applications.