Temperature control of furnace model

Hi ,

I am trying to model the furnace to heat gases to particular setpoint temperature(1500degree celcuis from room tempersature).

I am using sscfluids_house_heating_system as reference to develop furnace model.

I am not able to define temperature rise in this model. Inputs to this model are :

mass flow rate of fuel

temperature of fuel

humidity ratio of air

temperature of air

How should I change the paramaters of input side to 1500 degree celcuis as output temperature (measured through thermal port).

My another concern is how can get a time dependant temperature rise of gas from room temperature to set point temperature?

In current model when I attach temperature sensor to thermal port , and run the simulations , it just gives me output of temperature , I want to get the output where the temperature change is seen , that is rise in temperature from room temprature to set point.

I am using ENTU type heat exchanger to gain the heat from furnace and raise the temperature of gas (defined through gas properties).

Answer 1

[Yifeng Tang]

Hope it's not too late ...

It looks like the Furnance block is set up such that it produces (1) a burning temperature in the H port, based on the air-fuel ratio and (2) amount of heating energy available in the C_exh signal port. This is of course a simplied way of describing the behavior of a furnance, and as a result, changing the fuel flow won't directly affect the burning temperature but only the C_exh signal. This is because it's assumed that the amount air is proportional to the fuel mass, as set by the "percent excess air", and when you have less fuel, less air comes in, and the burning temperature remains unchanged, just with less available heating energy. This explains why the temperature at the H port doesn't seem to change no matter what you vary.

One way to change this is to make that "percent excess air" an input instead of a parameter, by making your own custom block. It should be a very simple change based on the original code. You may then probably couple the fuel flow and excess air, with some function or look-up table, so that when less fuel comes in, there is more excess air, and the temperature and available heat will both drop. Here is more info on using custom Simscape blocks: https://www.mathworks.com/help/physmod/simscape/lang/creating-custom-components.html