Summary of Week 1

In this first week, you looked at the definition of the first law of thermodynamics and their physical meaning. The first law is nothing but conservation of energy. The total amount of energy is conserved, but the energy can change its form.

You’ve learned the equation depicting the first law for closed and open systems. The mathematical interpretation of the first law is the energy balance equation. In energy balance equation for the closed system, the energy change of the system is described as the energy change of internal energy, potential energy and the kinetic energy. For energies in transit (the energies transferring between system and surrounding), only two types of energies are involved: the heat and work. For the open system, we have to include energy transfer accompanied with materials transferring across the system boundary.

The heat capacity is introduced to calculated the energy change using energy balance equations. Heat capacity is the thermal energy required to change the temperature of a material, thus so the heat change upon temperature change can be calculated by integrating heat capacity over the range of temperature range.

In Week 2, you will apply the energy balance equations to real problems and calculate the energy difference between two states. In these kinds of calculation, heat capacities are particularly required.

You will look at enthalpy changes with temperature and chemical reactions. For convenience in calculation, the concept of reference state and heat of formation will be examined.

The equation of state is particularly relevant to thermodynamics, since it relates the physical variables describing the condition of the system. The equation of state for ideal gases and non-ideal gases will be studied.

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Thermodynamics in Energy Engineering

Hanyang University