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
Target suction pressure and head pressure refer to specific operating parameters in refrigeration and air conditioning systems. The target suction pressure is the desired pressure in the evaporator, typically measured in psi or bar, which ensures efficient heat absorption from the environment. Head pressure, on the other hand, is the pressure in the condenser, necessary for proper refrigerant condensing and is influenced by ambient temperature and system design. Maintaining these pressures within their target ranges is crucial for optimal system performance and energy efficiency.
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
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.
The four methods for controlling head pressure in an air-cooled condenser include: Variable Speed Fans: Adjusting fan speed can optimize airflow based on temperature demands, helping to maintain desired head pressure. Refrigerant Flow Control: Using expansion valves or solenoid valves to regulate refrigerant flow can help manage pressure levels effectively. Water Spray Systems: Implementing water mist or spray systems can enhance heat exchange by cooling the condenser coil, thereby reducing head pressure. Ambient Temperature Management: Strategically placing the condenser in a location with optimal airflow and temperature can also help maintain efficient operation and control head pressure.
Controlling head pressure in an air-cooled condenser can be achieved through several methods: Variable Speed Fans: Adjusting the fan speed based on head pressure can optimize airflow and enhance heat rejection. Refrigerant Flow Control: Implementing expansion valves or modulating refrigerant flow allows for better control of the system's pressure levels. Ambient Temperature Monitoring: Using sensors to monitor ambient conditions can help adjust system operation dynamically to maintain optimal performance.
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.