THERMAL SYSTEMS DESIGN

COMPUTER PROJECT NO. 2

A helium liquefier operating according to the flow diagram shown in the following figure receives high-pressure helium vapor at Point 1, liquefies a fraction of the vapor at Point 4, and returns the remainder to be recycled at Point 8. In addition, a turbine is used to harvest energy from the original high-pressure helium vapor, and the exhaust vapor leaving the turbine at Point 5 joins the vapor from the separator at Point 6 to heat up the original helium vapor stream (that is the cold stream from Point 1 to Point 2). Note that the turbine power is not directly utilized in this process.

For all teams, UA=100 W/K for the heat exchanger, the inlet pressure at Point 1 and the turbine is 2000 kPa, and the separator is at 4.2 K and 100 kPa. Compute the mass flow rate at Point 4, the temperatures at Points 2, 7 and 8.

Task 1. Access the online database of fluids properties at the NIST Thermophysical Properties of Fluid Systems, https://webbook.nist.gov/chemistry/fluid/, and compute the enthalpy and heat capacity formulas for the vapor helium as functions of temperature at two pressures, 100 kPa and 2000 kPa.

Task 2. Analyze the entire processing system and formulate all equations needed to solve the problem.

Task 3. Compose a program using Matlab or MathCAD or any other programming languages to solve the equations composed in Task 2.ask 4.

Summarizing the solution procedures in a technical report with the following items:

• Problem statement including design parameters

• Description of design parameters and their equations.

• Computer program and results

• Sample hand calculation to check the computer results

• Discussions and conclusions.