It is due to pressure rising due to a bad condenser fan motor, bad capacitor, obstructing of airflowat the condenser, or a dirty condnser.
water as a coolant
fan cycling.3 way modulating valve
non condensebles in system dirty cond coil high ambient poss over charge
Head = (Pressure * specific gravity)/2.31 Head in ft Pressure in pound per in^2
static head
Excessive head pressure.
5 Causes of high head pressure: 1.) Dirty condenser tubes 2.) High temp entering condenser water 3.) Low flow of condenser water 4.) Water bypassing at division plate 5.) Non-condensables in the system
water as a coolant
Poor compressor performance should result in low head pressure as the system cools better than the compressor can pump.
High head pressure in a compressor can be caused by factors such as a dirty condenser coil, restricted airflow, overcharging of refrigerant, or a malfunctioning condenser fan. These issues can result in the compressor having to work harder to maintain proper pressure levels, leading to increased head pressure.
Operating an air cooled condenser with a head pressure that is too low can result in inefficient heat transfer, leading to reduced cooling capacity and potentially causing the system to operate with insufficient refrigerant flow. This can lead to lower system performance, decreased energy efficiency, and in severe cases, compressor damage due to liquid refrigerant returning to the compressor.
Condenser Backpressure is the difference between the Atmospheric Pressure and the Vacuum Reading of the Condenser, that is: Backpressure = Atm. Pressure - Condenser Vacuum Pressure Reading Usually, the condenser vacuum pressure is read by a manometer installed at the condenser. The atmospheric pressure is read using a barometer
The head pressure and compressor current would normally rise (strong winds and/or rain and/or very low air temperatures will reduce this effect). Less heat would be removed from the refrigerant and therefore deliver less cooling.
If the centrifugal pump supplying cooled water to the water-cooled condensers fails, the flow of cooling water will be disrupted. This lack of adequate cooling will result in higher condenser temperatures, which in turn decreases the heat exchange efficiency. Consequently, the head pressure in the vapor compression system will decrease, potentially leading to reduced system performance and efficiency. Overall, the system may struggle to maintain optimal operating conditions.
They do fail naturally but the some causes are engine overheating because of water pump failure, pressure problems in the head and water cooled oil coolers splitting and blocking the circulation leading us back to point 1.
Water-cooled condensers typically have lower head pressure compared to air-cooled condensers. Water-cooled systems are more efficient in transferring heat, resulting in lower operating pressures and temperatures. This can help in reducing energy consumption and improving overall system performance.
If the condenser fan becomes inoperative, the head pressure in the system would likely increase. This is due to an inefficient heat transfer process, causing the refrigerant to remain at a higher temperature, leading to higher pressure in the condenser. Additionally, the compressor may also overheat and trip the safety controls.