Other Considerations Equipment Spacing To adequately exhaust heat generated, certain minimum clearances must be maintained around the variable frequency drive. Solar Heating Exposure of the enclosure to the sunlight direct or reflected will result in solar heating.
So this decrease in fuel usage will be the savings. The outlet should be placed above the highest mounted VFD. Commercial cooling towers in Northern US states are drained in the winter and run fewer hours, but have high rebates and strong utility incentives.
Installation alternatives VFDs are available in different types of enclosures like most electrical equipment to suit the environment which they are to be installed. This model leverages all the fan capacity as one system.
The better heat conduction of the enclosure the more heat dissipated. As outside air temperatures fall or the setpoints are reached, fans do the opposite, cycling off one at a time until all fan motors are off.
It is important to check the manufacturers specifications when a filter is fitted. Increasing the fan speed will increase the air flow; but it will have effect on energy consumption and the increased rpm would affect the shaft of the fan because of increased rotational stress, besides subjecting the whole structure to vibration.
I hope you have also considered the increased drift losses from the cooling tower.
VFDs should not be mounted in direct sunlight or on hot surfaces. Filters installed on Fan units provide a better protection rating normally max IP54 but impede the flow of air.
But in which situations is it best to do this? Fans can be controlled to run for a given time at starting or temperature controlled to extend fan life and reduce audible noise. Please refer to the instruction manual or contact your local representative for manufacture derating.
All the heat loss is taken care of and can be directly mounted on a wall see instruction manual for further information. An important consideration is the effects of direct sunlight, in which all precautions should be taken to remove the effects by providing adequate shelter.
When equipment that generates heat is installed into another enclosure the heat must be dissipated. However, for large cooling tower fans, I think that a fixed speed motor is sufficient. Generally ambient air is drawn in at the bottom of the cabinet through and discharged through a ventilation opening at the top.
For aggressive environments one may use a stainless steel or plastic enclosure. One way is to increase capacity of cooling tower by installing another cooling tower cell. The fan may be spinning when a VFD is commanded to start.
Force ventilation may also be temperature controlled to minimize running time and increase the life expectancy of the fans. Environment The environment of a VFD installation determines the type of enclosure to be used.
VFD controlled cooling tower fans operate over many speeds as opposed to the fans on a single or two-speed motor starter. The volume of air required can be estimated using the formula: If your feed water costs or chemical treatment costs are high the drift effect of increasing the speed of the fans could cost much more than just the added electrical cost.
Filters should be inspected regularly for blockage as part of the maintenance schedule to ensure free air flow and correct operation. For example a 50 hp induction motor is installed for running the shaft as rpm. Consult the manufacturer of the cooling tower for minimum speed requirements.
Industrial cooling towers often operate multiple shifts and run all year long.Variable frequency drive on Cooling Tower. However, VFDs are only used for controlling the speed.
In a case like this, you will want the fan to operate at the maximum speed. VFDs are a good idea for energy savings and the cost and the size in the MCC have gone down, making them more economic. However, for large cooling tower. Variable Frequency Drives: Operation and Application with Evaporative Cooling Equipment Benjamin Cohen It is highly recommended that all VFDs for cooling tower fan appli- cooling tower system’s resonant frequency, so it is recommended.
Cooling Tower VFDs – Energy Savings with No Performance Dropoff. Commercial cooling towers in Northern US states are drained in the winter and run fewer hours, but have high rebates and strong utility incentives.
Let’s look at a Groom Energy customer example our engineers recently studied. VFD Cooling and Ventilation This paper is intended to be a guide for the installation of VFDs to ensure adequate cooling or ventilation is provided.
All power electronic equipment will dissipate heat which must be removed to prevent overheating of the semiconductor devices or other components.
VFDs and Cooling Towers; Posted January 20, by Pepper Hastings. Although it is best to consider VFD capabilities during a tower's initial design, VFDs can be implemented into existing applications effectively. Many resources offer comprehensive information on state, local, utility, and federal incentives that promote renewable.
A mechanical-draft tower is a common type of cooling tower used in HVAC applications.(Monthly) HPAC Show Product News. Both designs use one or more fans to provide the flow required to extract heat from process cooling water. causing leaving-water temperature to fluctuate.
this was achieved by cycling fans on and off.Download