tools, materials & knowledge for model makers
A thermosiphon is a method of passive heat exchange between the heat source and the heat sink. In the case here the engine is the heat source and the water tank is the heat sink. The fundamental issue when running the Whippet engine in this configuration was it was getting hot and the water was … Read more
Before starting the simple modelling I think it is worth looking at the known parameters for the boiler test object. From these there will be some simple assumptions and estimations. Assumptions Lumped point mass. Single temperature measurement represents the temperature of the object. Heat capacity does not change with temperature. Local air temperature represents ambient … Read more
Before going too far with the calculations I needed an initial check on the boiler test object repeatability. All of the data analysis will end up informing the insulation of the Burrell traction engine boiler. This initial look at the data will give me an initial feeling as to whether the data is good. Test … Read more
In model making and engineering we use wood as a thermal barrier, hence it is good to understand the thermal conductivity of wood. A typical example is in the insulation of a boiler. The thermal conductivity of wood is affected by: density moisture content grain direction structural irregularities temperature Density Plotting the thermal conductivity across … Read more
My original boiler heat loss test object was a round disc of mild steel and copper. However, this doesn’t relate that well to the actual boiler. This is so that I can test different types of boiler insulation and multi-layer insulation. My original idea for measuring the thermal insulation for the boiler was to make a … Read more
Looking at the thermal insulation of a boiler and just how thin I could make an insulator I started looking at Multi-Layer Insulation or MLI’s. The effective thermal conductivity of an MLI is in the order of 10-5 Wm-1K-1 as given by Sutheesh and Chollackal [ref 1]. The thermal insulation I achieved for the vertical boiler … Read more
After a few measurements on the vertical boiler, using the cooling curve to estimate heat loss, I achieved a reasonable level of thermal insulation. However, can I turn this into a more methodical approach in the home workshop? I can electrically heat a block of metal, it would be best if this was copper. Copper would … Read more
If a temperature difference exists between two points heat will flow from the point at the higher temperature to the point at the lower temperature. This flow will continue until equilibrium has been reached. The transmission of heat may be due to three different processes. Conduction – This is the process by which heat flows … Read more
Vertical vs Horizontal Steam Boiler, what is the difference? I made a vertical boiler as a test piece before making a horizontal boiler. Was that sensible and did it prove anything? I did learn the basic requirements of making and testing a boiler. I also learnt about fireboxes and how to get heat into the … Read more
Hopefully this is the final cladding of the small boiler. I say that as it is meant to be a test setup. A way of developing my knowledge and skills. However, at the same time this needed to also fulfill my need for it to look good. The boiler cladding consisted of a number of layers. … Read more