Patent Publication Number: US-2010131111-A1

Title: Air Conditioner Water Pump Energy Saving Apparatus

Description:
CROSS-REFERENCE TO FOREIGN PATENT CERTIFICATE 
     The entire content of this application document is based on the Patent Certificate Ser. No. M361002, issued in TAIWAN on Jul. 3, 2009. The inventor of the above said Taiwanese patent M361002 is hereby applying for a United States patent for the same invention. 
    
    
     THE FIELD OF THE INVENTION 
     This invention is an add-on energy-saving apparatus to a common split air condition system with a or a plurality of cooling water towers. This apparatus achieves energy savings by optimizing the control of cooling water pumps. 
     BACKGROUND OF THE INVENTION 
     An air-conditioner&#39;s electricity bill is often the biggest ticket item in commercial building&#39;s operating expense. Running the air conditioners smartly would save money for building owners, reduce the carbon foot-print, and help the United States to be more energy independent. 
     This invention relates to an HVAC add-on energy savings apparatus to any common split air-condition system. This apparatus achieves its energy-savings by optimizing the control of a or a plurality of cooling water pumps, based on the cooling water temperature difference and the compressor&#39;s pressure difference. 
     PRIOR ART 
     Commercial or industrial grade split air conditioner system usually comes with an air blower, a water cooling tower, an evaporation unit and a condensing unit. Conventionally, a split air condition system&#39;s compressor and cooling water tower are controlled independently. A split air condition system&#39;s cooling water pump for the cooling water tower is usually turned on with full power when the air conditioner is on, irrelevant of the building occupancy, the season, the weather or the humidity. 
     SUMMARY OF THE INVENTION 
     This invention&#39;s energy savings is achieved by frequency-changing the cooling water pump motor to reduce the pump motor load. The amount of the frequency-change is based the cooling water temperature difference and the compressor&#39;s pressure difference. This invention takes advantage of that the cooling water temperature difference and the compressor&#39;s pressure difference are the aggregate variation indication of the season, the weather, the humidity and the building occupancy etc., in which the air conditioner is operated. 
     This above said water temperature difference and the compressor pressure difference are measured at the steady state of an operated split air conditioner system with a or a plurality of water cooling towers. 
    
    
     DETAIL DESCRIPTION 
     This apparatus of this invention includes a return-water temperature sensor, a cooling water temperature sensor, a CPU circuit board assembly, a compressor high pressure loop sensor, a compressor low pressure loop tensor, and a compressor status sensor. 
     The apparatus of claim  1  wherein the CPU circuit assembly board is connected to a plurality of sensor ports and a plurality of control ports. 
     The apparatus of claim  1  wherein the CPU&#39;s sensor ports are connected to water temperature sensors and compressor&#39;s pressure sensors 
     The apparatus of claim  1  wherein the CPU&#39;s control ports are connected to a or a plurality of motor controllers, or frequency converters. 
     The apparatus of claim  1  wherein the CPU controls a plurality of frequency converters based on the water temperature readouts and the compressor pressure readouts. 
     The apparatus of claim  1  wherein the CPU sets the frequency converter to low if the water temperature difference between the outgoing water and return water is low. 
     The apparatus of claim  1  wherein the CPU sets the frequency converter to high if the water temperature difference is high. 
     The apparatus of claim  1  wherein the CPU sets the frequency converter to full power if the compressor&#39;s pressure difference is high. 
     FIG.  1 &#39;S Item Description:
       1 . Compressor     2 . Condenser     3 . Expansion Valve     4 . Evaporator     5 . Cooling Water Pump     6 . Cooling Water Tower   

       FIG. 2 , This Invention&#39;s Apparatus in a Typical Split Air Conditioner System with a Water Cooling Tower 
     FIG.  2 &#39;s Item Description:
       1 . Compressor     2 . Condenser     3 . Expansion Valve     4 . Evaporator     5 . Cooling Water Pump     6 . Cooling Water Tower     7 . Apparatus Housing (This invention from this item on)     8 . Microcontroller Assembly     9 . Cooling Water return temperature sensor     10 . Cooling Water out-going temperature sensor     11 . Frequency converter     12 . Compressor High Pressure Loop Sensor     13 . Compressor Low Pressure Loop Sensor     14 . Compressor Operation Sensor     15 . Cooling Fan   

       FIG. 4 , This Invention&#39;s CPU Control Flow Diagram