Crash Course Thermodynamics

Identify and memorize the three essential thermodynamic devices and their model assumptions, grasping their purposes and intuition to simplify problems; note when higher precision may require more assumptions.

Examine how heat exchangers transfer heat via sensible and latent modes, using evaporators and condensers, and apply the constant pressure assumption to model these devices.

Explore throttling devices in thermodynamics, including capillary tubes and expansion valves, which reduce pressure while keeping enthalpy constant, with no heat or work transfer.

Recap heat exchangers like condensers and evaporators, noting assumed constant pressure across them, and review ideal machines such as compressors, pumps, turbines, and fans, plus throttling devices with constant enthalpy.

Trace a refrigerant R20 cycle by constant entropy through the compressor, constant pressure in heat exchangers, and throttling, then identify saturated liquid quality and complete property values from tables.

Compute real values from the vapor tables to determine the state at five bar and five degrees Celsius as a superheated vapor, then plot the state on the diagram.

Trace the refrigeration cycle from state 1 to 4, using constant entropy and pressure steps, interpolate in 12 bar superheated tables, and determine quality and properties.

Learn to draw and analyze control volumes for thermodynamics problems by identifying boundaries, mass flows, velocity and area vectors, heat transfer, and work interactions.

Explore steady-state versus transient behavior and open versus closed systems in thermodynamics, using control-volume examples like balloons and faucets to show time and mass transfer affect properties.

Apply integration to real-world thermodynamics, from a one-dimensional line with a varying extensive property like internal energy to two- and three-dimensional control surfaces and volumes, using double and triple integrals.

Learn how work is calculated by integrating pressure over the volume change in compressible systems, and how work depends on the process path, shown via a piston and PV diagrams.

Apply Reynolds transport theory (RTT) to relate the time rate of change of any extensive property to mass flow, density, and velocity in a control volume.

Explore how the Reynolds transport theory applies to the three fundamental thermodynamic laws—continuity, the first and second laws—through control volumes, mass and energy balances, and entropy concepts.

Apply Reynolds transport theory to a steady-state open heat exchanger, derive conservation of mass across a control volume, showing mass entering equals mass leaving under constant properties and inviscid flow.

Use the first law for open systems to balance energy: kinetic, potential, internal energy, and flow work, with control surfaces, mass flow, and entropy-driven heat transfer concepts.

Explore how entropy counts microstates behind a macro state, with entropy proportional to Ω and tied to Boltzmann's constant, and how temperature increases Ω while higher pressure reduces it.

Explore how two macro states at different temperatures mix when a barrier vanishes, producing higher entropy and an arrow of time per the second law.

the second law states the entropy of the universe must be greater than zero, except in reversible processes, as heat flows between hot and cold reservoirs, linked by Maxwell relations.

review how closed systems remove mass transfer terms, convert differential forms to a time-rate equation, and treat energy as a state function while heat and work remain path-dependent between states.

Apply procedure for open and closed systems, using control volumes with mass flow and area vectors, heat transfer, and energy and entropy analysis to solve steady state and transient problems.

An open-system energy balance problem where a turbine extracts work as steam from a reservoir fills an evacuated tank, under adiabatic and quasi-static assumptions, yielding about 385 kilojoules of work.

Explore polytropic equations and the ideal gas law, linking pressure, volume, and temperature via n for isobaric, isothermal, adiabatic, and isochoic processes.

Explore how specific heats link temperature changes to entropy and internal energy, and how compressibility varies across fluids from incompressible to ideal gases, using the compressibility factor Z.

Analyze efficiency and performance in thermodynamic cycles, comparing actual work to maximum, and apply Carnot limits, first-law balance, and COP to refrigeration and heat pumps.

Assess a steady-state air conditioner cycle with a 30,000 BTU/hr load and a 3 hp compressor; Carnot COP about 26.5, actual COP about 3.93, suggesting 3 hp might suffice.