Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
COOLING OF HELMET WITH PHASE CHANGE MATERIAL
#1

COOLING OF HELMET WITH PHASE CHANGE MATERIAL

[attachment=18283]
1. Introduction

Motorcycle helmets greatly reduce injuries and fatalities in motorcycle accidents. Thus, many countries have laws requiring standard helmets to be worn by motorcycle riders. Safety is a primary feature of a motorcycle helmet. Modern helmets are fabricated from plastics, often reinforced with Kevlar and carbon fiber. The helmet has two principal protective components: a thin, outer shell made of acrylonitrile butadiene styrene(ABS) plastic, fiberglass or Kevlar and a soft, thick, inner liner about one-inch thickness usually made of expanded polystyrene foam or expanded polypropylene foam. The foam liner is very similar to that used in refrigerators as thermal insulation. The hard outer shell prevents puncture of the helmet by sharp pointed object and provides the framework to hold the inner liner. The inner foam liner is to absorb the crush during an impact. The one-inch thickness of insulation liner lining the interior of the helmet restricts and virtually eliminates the heat exchange with the outside wall of the most efficient part of the body. This creates an uncomfortable and dangerous hot environment to the head of the wearer. The interior of the helmet can quickly rise to the temperature between 37 C and 38 C.

2. Phase Change Materials (PCM)

A helmet cooling system eliminating the requirement of the power supply uses phase change material (PCM) to absorb all the heat generated from the head at a relatively constant temperature to provide cooling of the head. Thus, the interior is maintained at a certain cooled temperature which is close to the melting temperature of the PCM and creates a thermally comfort environment to the head without requiring external electrical power supply. The PCM is enclosed in a pouch and placed between the head and the helmet. When the head skin temperature is above the melting temperature of the PCM, the PCM begins to melt as it absorbs the heat from the head. A PCM-cooled system can be implemented in any kind of safety helmet.

4. Conceptual design of PCM-cooled helmet

The basic components of the PCM-cooled helmet are illustrated in Fig. 1. The key component of the helmet cooling system is the PCM pouch. The PCM is enclosed in the pouch. A flexible heat collector made of copper provides a good thermal path for conducting heat transfer from the wearer head to the PCM pouch. The heat collector is attached to a vinyl cushion which is filled with a water based solution (gel).

Design specifications
The PCM-cooled helmet is designed to maintain the head skin temperature at about Tskin = 30 C. It is designed to be capable of cooling the head continuously up to 2 hours which is referred to as the loading time tload = 2h . After the loading time, the stored heat in the PCM pouch needs to be dissipated to the ambient which is referred to as the discharging time, tdiscaharge. The helmet is designed to allow quick and easy retrieval of the PCM pouch from the helmet for discharging. The PCM pouch can be left on a table for heat dissipation to the ambient by natural convection, or the pouch can be immersed in water at room temperature to enhance heat dissipation to shorten the discharging time. If the PCM pouch stays inside the helmet, the discharging time will be longer.
Reply

#2
The design of a hull cooling system that uses phase change material (PCM) to absorb and store the heat produced by the user's head to achieve comfort cooling for the user. The PCM is packed in a bag and placed between the helmet and the user's head. The heat from the user's head is transferred to the PCM by conduction through a heat sink extending over the user's head. No power is needed for the cooling system. The temperature in the user's head is kept just above the PCM temperature, so the user would not suffer from an uncomfortable and dangerous hot environment in the head that will affect the user's alert. The cooling unit is able to provide comfort cooling up to 2 h when the PCM is completely melted. The heat stored in the PCM bag would then have to be discharged by immersing it in water for about 15 minutes to solidify the PCM before re-using it. The PCM hull cooling system is simple and has potential to be implemented as a practical solution to provide cooling comfort to motorcyclists.


The helmet is a critical safety equipment for two-wheeled drivers. The main purpose of the helmet is to protect the head from injury and protect the eye from sunlight and dust particles. It is crucial that the motorcyclist feels comfortable while wearing the helmet. The inconvenient equipment can affect the concentration and create hazards that could lead to accidents. The motorcyclist can be affected by the temperature that results in the loss of concentration. This work focuses on absorbing the heat produced inside the hull. To achieve this, a suitable Glauber Salt phase change material (PCM) is encapsulated within an aluminum foil. In addition, holes are created in the front and rear sides of the hull. This allows the circulation of the fresh air flow inside the hull so that the heat produced in the hull is instantly removed. Thus, a continuous cooling is achieved until the entire PCM is fused. Solid works is software of mechanical design; They provide tools to help you implement a sophisticated, standards-based architecture. Solid sketcher software works are used model and flow simulation, the heat is eliminated by providing the phase change material.
Reply

#3
I need On this topic ppt presentation. so how I should prepare the slides
Reply



Forum Jump:


Users browsing this thread:
1 Guest(s)

Powered By MyBB, © 2002-2024 iAndrew & Melroy van den Berg.