the flow of refrigerant in a heat exchanger system, commonly used in refrigeration and HVAC systems. The system starts with the compressor, which compresses the refrigerant gas (highlighted in red) and sends it through the discharge line to the condenser. The high-pressure refrigerant (now in liquid form) moves through the filter drier, where it is cleaned, and then enters the expansion valve (TXV). After passing through the TXV, the refrigerant experiences a pressure drop, cooling it down before entering the evaporator, where it absorbs heat. The refrigerant in the evaporator is a low-pressure, low-temperature gas (shown in blue) that transfers heat, turning into a gas. It then returns to the compressor via the suction line, and the cycle repeats. This system enables efficient heat transfer, critical for maintaining the desired temperature in cooling systems.