Solutions

The Hench Control Energy Management System is exclusively designed and manufactured in-house. The system is comprised of proprietary equipment that is conjoined with a sophisticated and extensive high-level programming language specifically for industrial refrigeration. The foundation of the system is specific for the purpose of reducing the energy requirements for the operation of compressors, condensers, evaporators and peripheral refrigeration equipment. In effect, the principal result is the reduction of energy used with regard to horse power (HP). To calculate energy savings, the Energy Management System uses proprietary formulas driven by thermodynamics and the physics relating to the system’s ability, performance, physical environment and atmospheric changes at any industrial refrigeration facility.

The system has the ability to operate at a basic level to provide simple operational controls without using any of the energy management components as one of the ways in which the system proves itself. With the use of a metering device such as a Power Pulse Meter and/or Current Indicator, the system will confirm the disparity between a standard control system and one driven by the energy management principles.

There are three main rules the system follows:

1. For every 1psig that the Low Stage Suction Pressure is raised, the system will save about 2% on the total HP in use.

2. For every 2psig that the Discharge Pressure is lowered, the system will save about 1% on the total HP in use.

3. Every facility will change its thermodynamic balance every moment of operation depending on demand, mass, atmospheric variances and process criteria.

From these major energy savings “rules,” the system derives and compounds other rules and formulas to achieve savings. The formulas and basic rules are the foundation of the Energy Management System. To achieve and maximize energy savings, the following procedures below need to be paradigm in nature.

With proper placement and calibration of Temperature sensors the system can:

• Raise the suction pressure if the correct liquid temp is getting to the Evaporators (Rule #1).
• Liquid temps more then 3 or 4 degrees below evaporator set point are wasteful.
• Reduce the number and duration of defrosts (Rule #2).
• Defrosts raise the Discharge Pressure.
• Defrosts add heat to the room that has to then be removed.

With the equipment installed and calibrated, then the system can optimize.

Optimizing Compressor Settings:

• Pressure Deadband.
• Avoids starting and stopping compressors. Startups cause demand charges.
• Minimum Capacity.
• This optimizes HP by balancing the load between compressors in a efficient way.
• Daily Pressure Offset.
• Taking advantage of off-peak energy costs.
• Used for production/non-production savings.

Optimizing Condenser Settings:

• Floating Head Pressure.
• Saves energy by only burdening the condenser with what it is designed to do.

Optimize Evaporator Settings:

• Find faults in the system.
• Stuck/Faulty valves.
• Defrost not completing.
• Defrosts continuing after frost is gone.

Energy Saving Features for Compressor Controllers:

• Controls up to two different suction control set points at different times a day.
• Controls suction pressure set point to within 1 psig of the set point.
• Automatically sequences compressors to their most efficient combination.
• Loads and unloads compressors to optimize system efficiency.
• Works as Booster or High Stage, coordinates when used in two-stage control.

Energy Saving Features for Condenser Controllers:

• Floats head pressure to lowest optimum operating pressure.
• Displays and controls on the difference between dry bulb and wet bulb temperatures.
• Automatically raises the discharge pressure set point during the defrost cycle.

Energy Saving Features for Hot Gas Defrost Evaporator Controllers:

• Allows shutting down neighboring evaporator during defrost.
• Defrost Blackout Table for defining time when defrost is not allowed for each evaporator on a seven day basis.
• Allows individual time offset of zone temp set points.
• Limits number of evaporators defrosting at same time.
• Allows fan cycling for energy savings when possible.