NON-ELECTROMECHANICAL, PUMPLESS LIQUID RECIRCULATION SYSTEM FOR AIR-COOLED CONDENSER AND COOLER ADIABATIC PRE-COOLING SYSTEM
A non-electromechanical, pumpless liquid recirculation system for adiabatic pre-cooling and evaporative heat exchange systems featuring an ejector device including motive fluid nozzle and an annular recirculating fluid chamber surrounding the nozzle. Motive make-up liquid under pressure is expelled from the nozzle into a mixing chamber. Recirculating fluid is introduced to and entrained with the motive make-up liquid at the outlet of the nozzle, and the motive force of the make-up liquid forces the combined make-up liquid and recirculating liquid out through the outlet of the ejector device to a water distribution system for the heat exchange system.
The present invention relates to adiabatic air pre-cooling systems for air-cooled condensers and coolers.
Description of the BackgroundAdiabatic air pre-cooling systems used with air-cooled condensers and air-cooled fluid coolers typically require an established liquid flow rate, typically of water, distributed over the entire adiabatic air pre-cooling media surface area, where a reservoir captures the residual liquid flow rate after leaving the adiabatic air pre-cooling media surface area, for subsequent disposal or recirculation. The purpose of the adiabatic air pre-cooling media is to pre-cool the air entering the air-cooled condensing coil or air-cooled fluid cooling coil thereby increasing thermal heat rejection capability. There are multiple adiabatic air pre-cooling medias, including but not limited to, corrugated cellulose paper pads, corrugated PVC pads, and wire type PVC pads. In one embodiment of an adiabatic system, water is distributed over the adiabatic media and the water that is not evaporated during the air pre-cooling process is disposed of down the drain. To eliminate water going to drain, recirculated system designs are employed. The current technology for recirculating liquid over the adiabatic air pre-cooling media is to utilize an electromechanical pump which requires electrical input power to provide the required liquid supply flow rate to establish the intended evaporation and heat transfer rates.
SUMMARY OF THE INVENTIONA limitation with utilizing an electromechanical pump is the requirement for both rotating and electrical components and rendering the equipment nonoperative in the event either one fails. Moreover, even partial operation of this electromechanical device may cause a significant reduction in the evaporation and heat transfer rates which in turn reduces the overall process efficiency. Current liquid pump technology leads to the eventual, random failure of either the mechanical or electrical components which typically occurs during the most critical process operating hours. Elimination of both mechanical and electrical components while maintaining desired liquid flow rate to the heat transfer component(s) would present a significant advantage. In addition, eliminating or reducing electrical costs (input power) as well as required maintenance are also beneficial. Finding a solution to eliminate rotating and electrical components as well as input power while providing the required liquid recirculation flow rate to the adiabatic air pre-cooling media has been particularly challenging.
This invention solves this problem by providing a solution that does not require any mechanical or electrical components to induce liquid flow, while providing both liquid recirculated and make-up flow rates to the adiabatic air pre-cooling media. Specifically, the inventors have discovered that driving a non-electromechanical, pumpless device (ejector) with an external, liquid make-up supply, coupled with the interconnecting piping, manual and modulating valves, electronic sensors, and liquid distribution system can successfully provide the necessary liquid flow rate onto the adiabatic air pre-cooling media for a wide range of operating conditions. This pumpless device coupled with an external, liquid make-up supply/pressure compliments one another to eliminate the requirement for an electromechanical device (i.e., pump).
According to a preferred embodiment of the invention, the recirculation system requires no motor or motorized pump. According to another preferred embodiment of the invention, the volume of entrained/recirculating fluid passing through the pumpless device in any time interval equals or exceeds the volume of the driving/motive fluid.
The foregoing summary, as well as the following detailed description of the preferred invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, the drawings show various embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
Features in the attached drawings are numbered with the following reference numerals:
Referring to
According to an alternate embodiment, shown in
The total liquid flow rate at the outlet of the mixing chamber is the sum of the motive make-up supply liquid flow rate at a specific pressure, the recirculating liquid flow rate at side port 7 and the ejector's entrainment ratio. The entrainment ratio is primarily a function of nozzle geometry and annulus diameter and may be adjusted by adjusting liquid supply pressure and back pressure.
Overall, the non-electromechanical, pumpless liquid recirculation system will provide the total liquid flow rate to the adiabatic air pre-cooling media without any rotating or electrical components as well as comparable input power in comparison to an electromechanical pump.
It will be appreciated by those skilled in the art that changes could be made to the preferred embodiments described above without departing from the inventive concept thereof. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as outlined in the present disclosure and defined according to the broadest reasonable reading of the claims that follow, read in light of the present specification.
Claims
1. A non-electromechanical liquid ejector comprising a make-up liquid chamber having an end port at a first end and a narrowed nozzle at a second end, an annular chamber located on an outside surface of said narrowed nozzle, said annular chamber in liquid communication with a source of recirculating fluid via a side port of said ejector, said annular chamber terminating at an outlet of said narrowed nozzle, and a mixing chamber located downstream of said outlet of said narrowed nozzle.
2. An adiabatic pre-cooling system for an air-cooled condenser or cooler having no electromechanical pump, said adiabatic pre-cooling system comprising:
- a plurality of adiabatic pads mounted on said air-cooled condenser or cooler,
- a water distribution system mounted above said plurality of adiabatic pads,
- a water collection device mounted below said plurality of adiabatic pads,
- a recirculation tank located and configured to receive water from said water collection tray,
- a non-electromechanical liquid ejector comprising a make-up liquid chamber having an end port at a first end and a narrowed nozzle at a second end, an annular chamber located on an outside surface of said narrowed nozzle, said annular chamber in liquid communication with a source of recirculating fluid via a side port of said ejector, said annular chamber terminating at an outlet of said narrowed nozzle, and a mixing chamber located downstream of said outlet of said narrowed nozzle,
- a make-up water supply under pressure and configured to deliver make-up water under pressure to said end port of said non-electromechanical liquid ejector.
Type: Application
Filed: Dec 19, 2022
Publication Date: Jul 6, 2023
Inventors: Gordon B. Struder (Taneytown, MD), Shridhar Gopalan (Taneytown, MD)
Application Number: 18/068,238