Waste Heat Recovery Of Centrifugal Air Compressor

1, Recyclable sources of heat
Compression heat (main heat source)
After multi-stage centrifugal compression, the temperature of the air increases significantly, and this heat is the main source of recovery.
Lubricating oil cooling heat
Lubricating oil is used for cooling and lubricating bearings and gears, taking away a large amount of heat, which can be recovered through an oil cooler.
Aftercooler/intercooler heat dissipation
During the inter stage cooling and post outlet cooling processes, the heat released by air cooling can also be recovered.

2, Common recycling methods
Water based waste heat recovery (most commonly used)
Install heat exchangers at the oil cooler and aftercooler to absorb heat with circulating water.
Produce hot water at 45-70 ℃, which can be directly used for:
Domestic hot water (hotels, dormitories, office buildings)
Process preheating (cleaning, drying, boiler water replenishment)
Winter heating/floor heating
Wind medium/wind water heat exchange recovery
Recycled hot air from the air compressor room is used for heating the factory building, drying materials, etc., suitable for scenarios with low temperature requirements.
Combined use of waste heat and heat pump
Using a heat pump to heat up the recovered heat to 80-90 ℃ to meet higher temperature process requirements and further improve utilization efficiency.

3, Core advantages
Energy-saving is remarkable
Air compressors consume a large proportion of industrial electricity, and waste heat recovery can convert most of the input electrical energy into usable thermal energy, greatly reducing additional energy consumption such as boilers and electric heating.
Reduce operating costs
Hot water/heating/process heat is basically "free", saving fuel and electricity costs in the long run.
Improve equipment operation
The heat is carried away in a timely manner, the oil temperature and exhaust temperature of the air compressor are more stable, the cooling load is reduced, and the efficiency and service life of the unit are improved.
Environmental protection and carbon reduction
Reduce the combustion of fossil fuels, lower carbon emissions and heat pollution, and meet the requirements of green factories and energy-saving certification.
4, Typical application scenarios
Factory/Park: Domestic hot water, winter heating, bathroom/cafeteria hot water
Textile, food, chemical industry: process preheating, cleaning water, drying heat source
Data center, pharmaceutical: constant temperature and humidity system preheating, clean process heat

5, Key points of design and selection
Priority is given to recovering oil temperature/heat from the aftercooler, which is stable, easy to recover, and requires low water quality.
The heat exchanger needs to consider anti scaling, anti-corrosion, easy maintenance, and match the flow rate and temperature rise of the air compressor.
Paired with a hot water storage tank to buffer thermal fluctuations and ensure continuous and stable supply.
Calculating the rated power, operating load rate, and annual operating hours of the air compressor can quickly estimate the heat recovery and recovery period.