🚀 Refrigeration Cycle Calculator & Simulator
- Boundary Temperature Control: Adjust the evaporating temperature (TL) and condensing temperature (TH) sliders to set the temperature limits of the cycle.
- Component Efficiency & Refrigerant Flow Control: Adjust the compressor's isentropic efficiency (η) and the refrigerant mass flow rate (m) to monitor the actual power consumption and refrigeration capacity.
- Real-time P-h Diagram Analysis: Observe how the 4-point cycle loop plotted on the pressure-enthalpy (P-h) diagram expands and contracts in response to temperature changes.
- COP & Power Readout: Monitor the total power consumption (kW) and system COP changes on the real-time measurement monitor to derive a design that maximizes energy efficiency.
📚 View Vapor-Compression Refrigeration Cycle Theory & COP Calculation Guide ▼
1. Vapor-Compression Refrigeration Cycle
The vapor-compression refrigeration cycle, which serves as the core foundation of modern air conditioners and refrigerators, acts as a thermodynamic pump that absorbs heat from a low-temperature heat source and rejects it to a high-temperature heat source. The cycle is composed of four physically separate main components:
- Compressor: Draws in the low-pressure saturated vapor refrigerant from the evaporator and adiabatically compresses it to a high-pressure superheated state (power input).
- Condenser: The high-temperature, high-pressure gas refrigerant rejects heat to the surroundings and condenses into a saturated liquid state.
- Expansion Valve: Undergoes a throttling process (isenthalpic, h1=h2) that rapidly drops the pressure and temperature of the refrigerant, bringing it into a wet vapor state.
- Evaporator: The low-temperature, low-pressure refrigerant absorbs heat from the substance being cooled (cooling effect) and evaporates into vapor.
2. Coefficient of Performance (COP) and Cycle Enthalpy Calculation Formulas
The performance of air conditioners and heat pumps is defined not by simple thermal efficiency, but by the Coefficient of Performance (COP), which refers to the refrigeration capacity achieved relative to the power input.
① Energy Analysis by Refrigeration Cycle State:
- Compressor work input:
wc = h2 - h1[kJ/kg] - Evaporator heat absorption (refrigerating effect):
ql = h1 - h4 = h1 - h3[kJ/kg] - Condenser heat rejection:
qh = h2 - h3[kJ/kg]
② Cooling Capacity (Ql) and Required Power (Wc):
Ql = m × ql [kW], Wc = m × wc [kW]
③ Coefficient of Performance (COP_R):
COP_R = Ql / Wc = ql / wc = (h1 - h3) / (h2 - h1)
The higher the evaporating temperature and the lower the condensing temperature, the more the cycle area (compressor power consumption) decreases, leading to a dramatic increase in COP. This explains the physical reason why electricity bills rise sharply during hot, humid outdoor conditions or when setting extreme low-temperature indoor targets.
3. Visual Understanding of Refrigerants and the P-h Diagram
The pressure-enthalpy (P-h) diagram is a thermodynamic chart with pressure (Log P) on the vertical axis and enthalpy (h) on the horizontal axis. In the center lies a bell-shaped saturation dome; the solid line on the left of the dome is the saturated liquid line, and the solid line on the right is the saturated vapor line. The refrigeration cycle undergoes heat exchange by traversing horizontally and vertically across the lower and upper sections of this dome. Eco-friendly alternative refrigerants like R-134a feature high latent heat capacity and excellent specific volume characteristics.