Calculation Methods for Waste Heat Recovery of Dryer Exhaust Gas

There are two main methods for calculating the waste heat recovery of dryer exhaust gas:

1. Energy Conservation Method

According to the law of energy conservation, the waste heat in the dryer exhaust gas can be calculated as follows:

Q = m * c * (T1 - T2)

Where:

• Q: Waste heat quantity, unit: kJ
• m: Exhaust gas mass flow rate, unit: kg/s
• c: Specific heat capacity of exhaust gas, unit: kJ/(kg·K)
• T1: Exhaust gas inlet temperature, unit: K
• T2: Exhaust gas outlet temperature, unit: K

2. Heat Transfer Method

According to the basic principle of heat transfer, the waste heat in the dryer exhaust gas can be calculated as follows:

Q = U * A * ΔT

Where:

• Q: Waste heat quantity, unit: kJ
• U: Heat transfer coefficient, unit: W/(m^2·K)
• A: Heat transfer area, unit: m^2
• ΔT: Heat transfer temperature difference, unit: K

The specific calculation steps are as follows:

1. Measure the dryer exhaust gas inlet temperature T1 and outlet temperature T2.
2. Look up relevant information to determine the specific heat capacity c of the exhaust gas.
3. Calculate the waste heat quantity Q according to the energy conservation method or heat transfer method.

Precautions:

• When measuring the exhaust gas temperature, pay attention to the selection of the measurement point to ensure the accuracy of the measurement results.
• When looking up relevant information, pay attention to the reliability of the information.
• When calculating the waste heat quantity, various factors should be considered, such as exhaust gas flow rate, humidity, dust content, etc.

The following are some measures for waste heat recovery and utilization of dryer exhaust gas:

• Use the waste heat to heat fresh air and improve the thermal efficiency of the dryer.
• Use the waste heat to heat water for domestic hot water or production water.
• Use the waste heat to generate electricity to provide power for the dryer or other equipment.

Waste heat recovery and utilization of dryer exhaust gas is an effective energy saving and emission reduction measure, which can improve energy utilization efficiency and reduce environmental pollution.