Waste heat recovery from exhaust gases

Waste heat recovery from exhaust gases - how to utilise the large amount of waste heat in exhaust gases

In order to do waste heat recovery of waste gas, first of all we have to make sure that the waste gas contains a lot of heat, then what is the characteristic of heat? Is the temperature is high, the higher the temperature of the waste gas, the greater the value of our recovery, the higher the available heat equivalent.

Through a set of exhaust gas waste heat recovery. We can recover the heat of the exhaust gas to use the heat to achieve other process conditions, the first, we can use the waste heat to heat our factory inside the need for water, for example, the staff of the bath water, but also for example, some of the factory inside the factory of the link, it needs to use hot water, and these hot water.

Before, the factory is likely to be through some small gas boiler, electric boiler to heat the water, if there is no part of this waste heat to do recovery, we need to consume a lot of natural gas and electricity to heat this part of the hot water needed.

But if our factory itself has a large amount of heat emissions of exhaust gas, then we can use this part of the exhaust gas through the exhaust gas heat exchanger to do a process of heating water, partially or completely replace our previous use of electric hot water boilers and gas hot water boilers, so as to achieve a reduction in gas costs or electricity costs, that is, to save our energy costs.

So which factories will have more high temperature exhaust gas emissions? 

For example, aluminium factory, in the smelting process of the smelting furnace, the need for non-stop emission of high-temperature flue gas, and the smelting furnace inside the flue gas temperature of up to 600 degrees, this part of the heat is large, calorific value of the bit is also high, belongs to the recycling value of the waste gas is particularly large, and secondly, some of the electronic electronic components factory, they also need to use a very large number of combustion links, these combustion links inevitably discharge a large number of waste gas, and is the High temperature exhaust gas, this part of the heat, are I can be completely recycled.

Non-corrosive, non-humid environment, heat recovery device can be carbon steel structure, and stainless steel we will usually be used in high temperature, high humidity, there are traces of weak acids and alkalis in the environment, this is more important for the life of the equipment, but we have just talked about the use of that exhaust waste heat to heat the water, such as hot water in the factory's staff bath. And process hot water can be heated by the waste heat of the exhaust gas, a waste gas waste heat recovery device has 2 sets of inlets, respectively, the import and export of exhaust gas and water import and export, high-temperature exhaust gas into the equipment, low-temperature exhaust gas discharge equipment, low-temperature water into the equipment, high-temperature water discharge equipment, so as to achieve the use of waste heat exhaust gas.

After the hot water is generated, how much benefit does it have in the end? Now we talk about a case, this case is a car factory, his own exhaust gas exhaust temperature of 260 degrees, an hour, the amount of exhaust gas discharged 8000 standard square.

There is a washing process inside the process, the washing process requires hot water temperature is 70 ~ 80 degrees, every day to maintain the process of hot water power is 1200 degrees of electricity. Calculate our 260 degrees of exhaust gas into the equipment can provide the power, the power of up to 400 kilowatts per hour, and the power of the electric boiler 1200 kilowatts, so our equipment if used to heat the water, you can fully meet the entire production process to the need for hot water, and do not have to use the electric boiler equipment.

According to the conversion, we save electricity is 1200 degrees a day, every day can save electricity, is 1200 yuan, according to a year's time to conversion, probably he can save electricity a year, is 360000 yuan, we say this benefit is not very considerable?