Weblog

مطالعه مقایسه‌ای دقیق و دسته‌بندی‌شده بین دو نوع کویل فین تیوب (فین آلومینیومی — تیوب مسی) و کویل فین تیوب با تیوب آلومینیومی، از منظر انتقال حرارت، تحمل فشار و مقاومت به خوردگی ارائه شده است.
20Nov

Comparative Study Between Two Types of Fin Tube Coils

A detailed and categorized comparative study between two types of fin tube coils (aluminum fin - copper tube) and fin tube coil with aluminum tube, from the perspective of heat transfer, pressure resistance and corrosion resistance, is presented. Construction and materials Coil type A (aluminum fins + copper tubes): Fins are aluminum (common alloys) and tubes are copper (Cu). Fin-to-tube connection is commonly made by mechanically wrapping the fin around the tube, brazing/soldering, or using expanded joints. Coil type B (aluminum fins +...

By Articles, Technichal Points, Training,
Read more...
مقایسه مهندسی تیوب‌های مسی 8/5" با ضخامت‌های دیواره 0.50، 0.63 و 0.70 میلی‌متر
18Nov

The engineering comparison of 5/8″ copper tubes with wall thicknesses 0.50 mm, 0.63 mm and 0.70 mm used in a water coil (fin-tube) with aluminum fins

Below is the engineering comparison of 5/8" copper tubes with wall thicknesses 0.50 mm, 0.63 mm and 0.70 mm used in a water coil (fin-tube) with aluminum fins. Internal heat transfer (controlled by conduction and convective heat-transfer coefficient) Internal convective heat-transfer coefficient (hi): for the same volumetric flow rate, thinner-wall tubes (0.50 mm) have a slightly larger internal radius and therefore slightly lower pressure drop and a similar or slightly higher hi compared with thicker tubes. Changes are usually small and mainly...

By Articles, Technichal Points, Training
Read more...
فین ستاره ای آلومینیومی
11Nov

Aluminum star-shaped fin

This study examines the effect of an aluminum star-shaped fin, placed along the axis of 5/8-inch copper tubes with a specific twist, on heat transfer in a shell-and-tube evaporator. The objective is to evaluate the enhancement of heat exchange and the reasons for using this geometric arrangement in refrigeration and HVAC applications. Fin design and configuration The star-shaped fin is formed from aluminum sheet into a multi-branch profile that fits inside a 5/8-inch copper tube and is twisted gently around the longitudinal...

By Articles, Technichal Points, Training,
Read more...
Comparison of mechanical pressure resistance in 5/8 inch tubes with wall thicknesses of 0.5, 0.63, and 1.0 mm
04Nov

Comparison of mechanical pressure resistance in 5/8 inch tubes with wall thicknesses of 0.5, 0.63, and 1.0 mm

Introduction: This study briefly examines the mechanical and thermal behavior of copper tubes (5/8 in. size) with three different wall thicknesses (0.5 mm, 0.63 mm and 1.0 mm) in fin-tube coils. The goal is to determine approximate allowable pressure and temperature ranges and to explain performance differences resulting from wall-thickness variation. Material properties and assumptions: Material: commercial copper (e.g., C110) with ultimate tensile strength around 200–250 MPa and typical yield/working strength ~220 MPa, Young’s modulus ≈ 110 GPa. Outer tube diameter 5/8 in ≈...

By Articles, Technichal Points, Training,
Read more...
نقش اکسید آلومینیوم در کویل فین تیوب (فین آلومینیومی و تیوب مسی): تأثیرات بر انتقال حرارت و خوردگی
30Oct

The Role of Aluminum Oxide in Fin Tube Coils Aluminum Fins and Copper Tubes

Effects on Heat Transfer and Corrosion Aluminum oxide (Al2O3), present as an oxide film on aluminum fins or as suspended/ deposited particles, has both positive and negative effects on the performance of fin tube coils (aluminum fins with copper tubes). Below is a concise review of these effects and the underlying mechanisms. Positive effects • Surface protection: A passive aluminum oxide film can act as a relatively stable protective layer that inhibits further corrosion of aluminum. This layer shows reasonable resistance to mildly...

By Articles, Technichal Points, Training, ,
Read more...
حذف یا کاهش فاصله هوایی بین فین آلومینیومی و تیوب مسی در کویل
28Oct

Elimination or Reduction of Air Gap between Aluminum Fins and Copper Tubes in Coils

Eliminating the air gap between aluminum fins and copper tubes in fin-and-tube heat exchangers (coils) is an important step in design and manufacturing that directly affects thermal performance, energy consumption, durability, and operating costs. This study examines why the issue matters, the effective heat-transfer mechanisms, technical and economic consequences, and practical implementation methods. Importance of Contact-Based Heat Transfer In fin-and-tube exchangers the primary objective is rapid and efficient heat transfer from the tube surface (carrying hot or cold fluid) to the air...

By Articles, Technichal Points, Training, ,
Read more...
Why Copper Tubes Are Used in Fin-and-Tube Coils
28Oct

Why Copper Tubes Are Used in Fin-and-Tube Coils

Introduction The choice of tube material in fin-and-tube coils strongly affects performance, durability, and life-cycle cost in HVAC, chillers, boilers, and heat exchangers. Copper (Cu) is one of the most common choices. Below are technical, organized reasons why copper tubes are preferred. 1. High Thermal Conductivity • Copper has very high thermal conductivity compared with many common metals (e.g., carbon steel). • High conductivity enables fast, efficient heat transfer between the fluid inside the tube and the external fins, improving overall coil heat-transfer effectiveness. •...

By Articles, Technichal Points, Training,
Read more...
تأثیر فاصله فین (FPI) در کویل فین-تیوب بر راندمان حرارتی و افت فشار
30Sep

Effect of Fins Per Inch (FPI) in Fin-Tube Coils on Thermal Efficiency and Pressure Drop

Fins per inch (FPI) is a key design parameter in fin tube coils that directly affects heat transfer performance and airside pressure drop. Increasing FPI means more fins per unit length; this change brings both benefits and trade offs. Effect on Thermal Efficiency • Increased heat transfer area: Higher FPI increases the total fin surface area in contact with air, typically raising the overall heat transfer capacity of the coil. • Improved boundary layer disruption: More fins create more frequent air–metal interfaces, which...

By Articles, Technichal Points, Training, , , , ,
Read more...
Flow of Refrigerant and Water in a Shell-and-Tube Evaporator in a Vapor-Compression Chiller
07Sep

Flow of Refrigerant and Water in a Shell-and-Tube Evaporator in a Vapor-Compression Chiller

A shell-and-tube evaporator is one of the most common heat exchanger types used in vapor-compression chillers. This article examines the refrigerant and water flows, their thermal and hydrodynamic interactions, and design and operational considerations from a mechanical engineer’s perspective. General Description and Flow Configuration A shell-and-tube evaporator typically consists of a bundle of tubes placed inside a shell. In a typical chiller, the refrigerant flows inside the tubes while the chilled water (or brine) flows in the shell; depending on design, this...

By Articles, Technichal Points, Training,
Read more...
Research: Oil Cooler (Copper Fin-and-Tube Coil Heat Exchanger)
31Aug

Research: Oil Cooler (Copper Fin-and-Tube Coil Heat Exchanger)

Introduction An oil cooler is a device used to reduce the temperature of oil in hydraulic systems, lubricating systems, and gearboxes. One common type is the copper fin-and-tube coil heat exchanger, which is widely used because copper has high thermal conductivity and the fins provide a large heat-transfer surface. Construction and Components Shell and frame: The housing that holds the coil and connections; commonly made of steel or aluminum and designed to resist corrosion and pressure. Coil (copper tubes): Copper tubes through which oil flows (depending...

By Articles, Technichal Points, Training, ,
Read more...