Can we make electricity from heat?

In summary, the conversation discusses the potential of creating a heat engine using a refrigeration cycle and a different fluid with a lower boiling point. The process involves using a mixture of silicone oil and liquid isoprene to turn a turbine and generate power. However, the efficiency of this system is questionable and the concept of a perpetual motion machine is not possible.
  • #1
heatupgrade
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I am a refrigeration technician with a fascination for heat pumps. I wonder if we can make two systems in parallel. The Carnot heat engine is used to describe the steam locomotive. I want to use a different fluid with a lower boiling point to create a heat engine using a refrigeration cycle.

Imagine a common natural chemical Isoprene because it boils at 94 degrees Fahrenheit. the roof of the house is heating up and the isoprene boils inside a hermetically sealed system. A nozzle sprays a mixture of silicone oil and liquid isoprene and turns the turbine and an alternator pulls electrons from the Earth and powers a pump and compressor and two fans. Air from the building absorbs the heat from the isoprene and it condenses back into a liquid and the cycle begins. A battery , compressor and capacitors will be useful to start the process. A small flame might be beneficial to control the boil.

Once the process begins, it should proceed in the mythical fashion of a perpetual motion machine. We are cheating because the heat of the building adds fuel . Heat is energy and it is often thought of as waste in the refrigeration process.
 
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  • #2
I can't comment on the efficiency or otherwise of the Isoprene cycle but I don't know what you mean by an "alternator pulling electrons from the earth". Electrical power is not generated that way at all.
Furthermore I would be very surprised if there would be enough heat difference to to generate any useful power. Just look at the heat and pressure required in a coal fired power station to generate a useful quqntity of power.
 
  • #3
Sorry, but perpetual motion machines are not possible and we do not discuss them here. If you look at the efficiency equations for heat pumps and heat engines, you will see they are inverses of each other; the maximum efficiency of such a system is exactly 100%: no more.

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1. How can we generate electricity from heat?

There are several ways to generate electricity from heat, including thermoelectric generators, steam turbines, and thermionic converters. These methods involve converting heat energy into mechanical energy, which is then used to turn a generator and produce electricity.

2. Is it efficient to make electricity from heat?

The efficiency of generating electricity from heat depends on the specific method used. Thermoelectric generators, for example, have an efficiency of around 5-8%, while steam turbines can have efficiencies of up to 50%. However, the overall efficiency of converting heat into electricity is limited by the second law of thermodynamics.

3. What are the sources of heat that can be used to generate electricity?

Heat can be generated from a variety of sources, including fossil fuels, nuclear power, geothermal energy, and solar energy. The most common method of generating electricity from heat is through the use of fossil fuels, such as coal, natural gas, and oil.

4. Can we use waste heat to generate electricity?

Yes, waste heat can be used to generate electricity through the use of combined heat and power (CHP) systems. These systems capture the waste heat from industrial processes or power generation and use it to produce additional electricity, increasing overall efficiency.

5. What are the advantages of generating electricity from heat?

Generating electricity from heat can have several advantages, including reducing the use of fossil fuels, decreasing greenhouse gas emissions, and increasing energy efficiency. It can also provide a reliable and stable source of electricity, as heat-based power plants can operate 24/7 without being affected by weather conditions.

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