CO₂ Heat Pump Cycle Analyzer

Interactive GUI application for analyzing the thermodynamic cycle of a transcritical CO₂ heat pump. Enter measured state-point data and compressor specifications, and the tool computes the full cycle and draws P–h and T–s diagrams.

Features

• Four state-point inputs (pressure & temperature at compressor inlet/outlet, before throttle valve, and pressure after throttle valve).
• Compressor inputs (displacement in m³/h, stroke volume in m³, 4 strokes).
• Thermodynamic properties computed with CoolProp (enthalpy, entropy, density, quality).
• Automatic determination of evaporating temperature from pressure (state 4).
• P–h diagram with logarithmic pressure axis and saturation dome.
• T–s diagram with saturation dome.
• Computed performance metrics: COP (heating & cooling), mass flow rate, heating/cooling capacity, compressor power, RPM.

Requirements

• Python ≥ 3.9
• Packages listed in requirements.txt

Installation

pip install -r requirements.txt

Usage

python co2_gui.py

1. Enter the measured pressures and temperatures for states 1–3 and the pressure for state 4.
2. Enter the compressor displacement and stroke volume.
3. Click Calculate & Plot.

Running Tests

python -m unittest test_co2_cycle -v

File Overview

File	Description
co2_cycle.py	Thermodynamic cycle calculations (CoolProp wrapper)
co2_gui.py	Tkinter GUI application
test_co2_cycle.py	Unit tests for the cycle calculations
requirements.txt	Python dependencies