Thermal Work Limit, the way to Heat Safety.

 (Thermal Work Limit), the way to Heat Safety..

- Monitoring environmental working conditions for heat stress indices such as Thermal Work Limit 

TWL

is important to help minimise the potentially deadly risks of working in the heat. So, TWL will assist with the management of heat stress problems

Thermal work limit (TWL) has been widely adopted in many countries, which resulting in a reduction in heat illness and lost production. One of these countries is 

UAE, 

The TWL heat stress index has been included in the EHSMS code of practice for the management of Heat Stress.

- The TWL device can 

#measures

air temperature, humidity, radiant heat and wind speed to come up with instructions for work, rest and hydration plan.

- TWL device as you can see in the attached pictures, contains Colorful LCD backlight tells you the risk level based on the TWL value.

For example, 

#red means unsafe for work, 

#yellow means buffer zone and 

#green means safe for work. We can explain these in more details below:

♦️ Green: If TWL Value Between (140 - 220 <), then its 

#Low risk un-restricted zone. And This condition is safe for all continuous self paced work and There is no limit on work for workers who are drinking adequate fluids and can take rest breaks when they need to.

♦️ Yellow: If TWL Value Between (115 - 140), then its

#Medium risk Cautionary zone . And the Precautions should be as below:

- An adequate intake of fluid is also required to ensure proper replacement of fluids lost in sweat in the specific hot environmental conditions.
- Working alone outside should be avoided
- Practice adequate work-rest schedule
- unacclimatised workers should not be at work


♦️Red: if TWL Value below 115, then its 

#High Risk Zone. And the Precautions should be as below:

- At this level, work is regarded as unsafe, meaning only maintenance and rescue operations should take place
- Rest cycling required (for every 20 minutes of work, 40 minutes of rest must be scheduled)
- No person should work alone
- No unacclimatized person on work
- Workers must drink 600ml of water every half-hour (Use personal water bottles when on site)
- compulsory dehydration testing is required at the end of each shift.

⭕️ For more Information you can refer to Abu Dhabi EHSMS code of practice for the management of Heat Stress..

 

Thermal Analysis and Heat Recovery Measures in Retrofitting a Modular Crude Refinery


In the process of retrofitting a modular crude refinery, the thermal analysis and implementation of heat recovery measures are central to achieving efficiency improvements, reducing operational costs, and enhancing environmental sustainability.

Thermal Analysis

1.1. Heat Balance Assessment:
- Conduct a comprehensive heat balance assessment of the existing refinery processes to identify heat sources and sinks.
- Accurate data on heat flows, temperatures, and thermal loads are fundamental to the retrofit process.

1.2. Thermal Efficiency Evaluation:
- Calculate the current thermal efficiency of the refinery, which serves as a baseline for measuring improvements.
- Assess the efficiency of key heat exchange processes, such as distillation, cracking, and heat recovery.

1.3. Energy Audit:
- Perform an energy audit to identify areas where thermal energy is wasted or underutilized.
- Pinpoint energy-intensive processes and potential areas for improvement.