This TXV bulb is charged with the same refrigerant used in the system, some of which remains liquid under all operating conditions. What is it called?

A TXV (Thermostatic Expansion Valve) bulb that is charged with the same refrigerant as the system and retains some liquid under all operating conditions is known as a liquid-charged bulb. This type of bulb allows for better sensitivity and quick response to temperature changes in the evaporator.

The liquid in the bulb does not evaporate completely; instead, it remains partly in liquid form, which means that it can effectively respond to changes in the temperature of the refrigerant entering the evaporator. This responsiveness ensures precise control of the superheat in the system, allowing for optimized performance and efficiency.

In contrast, other types of charging methods, like gas-charged bulbs, would not retain liquid under all operating conditions, which would reduce the control effectiveness. The unique characteristics of the liquid-charged bulb make it the preferred choice for applications where accurate temperature regulation is critical.