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Production of Wind Mill Energy From Exhaust of A/C Plant

Wind Turbine

I am working in a building which is centrally air conditioned. I got the idea of using the exhaust wind of Air conditioning plant to rotate the turbine for producing energy. If my idea of producing electricity from windmill which can be rotated by the exhaust of A/C plant comes true, then there will be an energy revolution in the areas where there is no wind mill due to lack of constant flow of wind. To date, the wind mill works in only coastal areas and not in places away from coastal regions.

The A/C plant works for at least 12 hours and that means the the wind mill can generate energy daily for twelve hours without need of natural wind. In off duty hours if there is natural wind, the wind mill can produce energy, but for at least twelve hours the exhaust air can rotate the wings of windmill and the air can be utilised for energy production which is otherwise going waste.

This is an idea to produce energy by using the exhaust air from Air conditioner in A/C buildings which is otherwise going waste. I just want to let the world know about the utility of Air from Exhaust of Air conditioner which is going waste. By my calculations we can produce energy equal to 12-15% of the total energy consumption in a building having an A/C plant . The cost of Wind mill turbines can be recovered in three years and after that the energy is produced free of cost . In this way we can produce energy in the places far off from coastal
areas where till date no wind mill energy is working due to lack of constant flow of wind.

By implementing this technique of horizontal wind turbine we can produce 26% cost of the energy of the investment which is needed to start this project and the production is totally green , there is no carbon emission, no smoke, no pollution and we are only using the wind that otherwise is going waste all over the world.

The wind turbine is not going to effect the efficiency of the A/C plant, rather it helps the A/C plant as can be seen from the lab experiments.

1. Benefits of the exhaust air energy recovery system

The energy recovery system is designed in a way that the released waste energy from any exhaust air system is converted to useable energy. As the wind from the exhaust air is readily available and concentrated every time the exhaust air system is operating, the energy generated from the system is predictable and constant in value. With constant rotational speed of turbine, over speed control is not required as only small rotational speed fluctuation is experienced. This feature can increase the longevity of the turbine due to less fatigue experienced. Besides, wind blown by the exhaust‘s fan has a better quality compared to natural wind. Thus, the statistical analysis of wind characteristic over a period of time is not required before deployment of the turbine. In addition to that, selection of the wind turbine for the system would be simpler because the rated speed of the turbine is based on the exhausted wind and power output generated from the system is easily predictable.

2. TABLE 1: LABORATORY TEST RESULTS :

An exhaust air energy recovery system without resulting in negative impact is designed. The performance of the( Wind turbine-)WTs are efficiently boosted by integrating with an enclosure. Diffusers mounted at an optimum angle created venture effect and the exhausted air flow was improved. Besides, common safety mishaps such as blade failure problem are eliminated with the installation of the enclosure. It could act as a protective cover to protect the entire system. -Due to the simplicity of the design, this energy recovery system is retrofit-able to any existing exhaust air system with minimum visual impact.

From the laboratory test conducted, installed WT is able to generate electricity without pulling down the original performance of the cooling tower. Instead, the cooling tower’s performance was enhanced as air volume flow rate to the cooling tower is raised 8.6% higher. By integrating the WT with an enclosure to the design, the WT’s performance is improved where the rotational speed is raised from 463.72 rpm to 500.98 rpm. On site testing was conducted to further confirm the actual performance and reliability of this system. It was observed that the released air speed from the cooling tower increased by 0.4% more compared to the conventional cooling tower. In terms of the motor’s power consumption, there was no significant difference observed for both test cases (7.0~7.1 kW). The implementation of this energy recovery system is possible to conserve power consumption from the cooling tower by up to 13%. By turning what was a wasted energy to useable energy like electricity, this energy recovery system has a high market potential and fast payback period as there are numerous usages of exhaust air system globally. It can be used as supplementary power for building lightings or fed into the electricity grid for energy demand in urban buildings.

Suresh Kumar's picture

Thank Suresh for the Post!

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Discussions

Harry Valentine's picture
Harry Valentine on Nov 28, 2013 7:00 pm GMT
Hello Suresh . . . . air-cooled air-conditioners make very inefficient use of energy. One method by which to reduce energy consumption would be to combine an air-cooled air-conditioner with a very tall thermal chimney . . . . heated air would flow into the base of the chimney and rise upward to create a powerful upward draught that could also activate wind turbines installed at other points around the base.
Carl Luther's picture
Carl Luther on Dec 3, 2013 7:00 pm GMT
A couple comments, Suresh - 1) I suspect that your building employs evaporative cooling. Evaporative coolers are typically 100% makeup air units that require relief vents in order to move cooler (though high latent-heat content / high humidity ...) air through the building. Most buildings with DX (refrigeration) air conditioning would recirculate in order to retain as much of the conditioned air as possible. If utilizing the condensor fans of these systems, you could impede air flow that would result in higher refrigerant pressures and lower equipment llife. In any case, installation of a turbine in an air stream increases friction. This will have a tendancy to restrict air flow, and may result in higher energy requirements for your fan. If the system has powered exhaust, the same would also hold true there - placing a turbine either on the suction or discharge of a fan will increase resistance and will likely either impede the function of that system, or result in higher energy requirements to perform the work. Unless it is a natural draft / convection system (such as described by Mr. Valentine above...) I would be very cautious about putting anything into a system that would increase the friction losses within that system. You are likely to lose much more than you would gain. 2) Perhaps it's different in India, but within the United States, constant wind most definitely occurs in non-coastal areas. There are large wind farms in Texas, Arizona, New Mexico, the Great Plains states, inland California, Idaho and the Dakotas.
Joseph A. Olson, P.E.'s picture
Joseph A. Olson, P.E. on Dec 3, 2013 7:00 pm GMT
It is unclear how this 'system' operates. If it is a windmill placed on the discharge side of a FAN driven water cooling tower, then what is missing is the HP or Watts that is being produced by the windmill. If it is only 'freewheeling' as it appears, then there is no free energy. At the time energy is being extracted it will increase the static pressure of the driven fan by at least the amount withdrawn. This is akin to using an electric motor to drive a generator, that drives the original electric motor...an impossible perpetual motion machine.

As to windmills in general, they do not have a constant input RPM and therefore can only produce Direct Current that must be sent thru an inverter to get transmissible Alternating Current, with some energy loss. The mud also use 'permanent magnets' which are not permanent and the best magnets use rare Earth elements that are environmental disasters to produce. See "Green Prince of Darkness" at FauxScienceSlyer for more info.

Suresh Kumar's picture
Suresh Kumar on Dec 3, 2013 7:00 pm GMT
Dear Friends, I am talking about the A/C buildings which have an A/C unit of 50 tonnes or more and the exhaust fan is used at the top of the building . You just go near the exhaust fan and you will realize how much energy is being wasted which can be used to produce electricity by installing HORIZONTAL TURBINE . For details you can go to the link http://www.indiegogo.com/projects/production-of-wind-mill-energy/x/5486078 . It will make a clear picture. thanks and regards suresh kumar
Vince  Marshall, CEM, MBA's picture
Vince Marshall, CEM, MBA on Dec 4, 2013 7:00 pm GMT
Suresh,

I like your line of thinking about capturing energy from anywhere... Trouble is your energy source (fans) consumes electricity and anything that harvests energy from that air stream restricts that flow and will cause kW consumption on your HVAC system to go UP.

Good job for coming up with this idea, but this one is unlikely to pan out.

mohan t p's picture
mohan t p on Dec 5, 2013 7:00 pm GMT
The system envisaged also consumes lot of power which needs o be drawn from the grid. Hence the system cost considering the input cost based on average ACOS(Average Cost of Supply) may not be that lucarative for the cost effectivenebss of the sysyten. Over and above the ACOS, there will bea additional money outflow towards Taxes and Electricity duty, which most of the Indian Suppliers charge on Ad-valorem basis
Suresh Kumar's picture
Suresh Kumar on Dec 5, 2013 7:00 pm GMT
Dear Mr.Vince, The turbine installed on the air stream about some distance away is going to increase the efficiency of the exhaust fan and the power consumption is not going to be effected as you can see in the lab results in my report ---" the cooling tower’s performance was enhanced as air volume flow rate to the cooling tower is raised 8.6% higher. By integrating the WT with an enclosure to the design, the WT’s performance is improved where the rotational speed is raised from 463.72 rpm to 500.98 rpm"--Please see my report again.Thanks Dear Mr Mohan this project is converting kinetic energy into electric energy so there is no power is required.
Suresh Kumar's picture
Suresh Kumar on Dec 5, 2013 7:00 pm GMT
Dear Mr Mohan ,this project is converting kinetic energy into electricity so no power consumption is there. Moreover the cost of installation can be recovered in 3 to 4 years. Thanks
Fred Flork's picture
Fred Flork on Feb 12, 2014 7:00 pm GMT
Dear mr kumar. Some of the previous comments have been too polite. Your concept defies the laws of physics. You cannot put power into a fan and then extract power from a turbine. There is no net energy gain. Your calculations may show that there is sufficient exhaust wind velocity to turn a turbine wheel at a particular speed, but as soon as you hook up the turbine to a generator the amount of energy produced can only be provided by the driving fan. Either the fan will draw much more power to try to maintain flow rate or if you we're limiting the power draw of the fan, the flow velocity would fall drastically and make the cooling tower ineffective. What you are proposing simply does not work. The papers that have been published on this topic which have shown a good turbine speed with no additional power input to the fan are flawed because they did not connect a generator to the turbine.
Abhishek Menon's picture
Abhishek Menon on Apr 3, 2014 6:00 pm GMT
Contrary to what is believed the turbine will actually help in boosting air flow, but ONLY IF THE TURBINE HAS HIGHER SPEED THAN THE DISCHARGED WIND SPEED. This creates a low pressure region in front of the turbine which actually helps the fan's cause. Of course, when generator is loaded, it should be so done that the turbine speed remains greater than the wind discharge.

Here is an analogy that came to my mind. Suppose a vehicle is moving on a level road with the engine producing a fixed amount of power. If the road suddenly slopes, the power requred for the same load will reduce. The turbine and diffuser arrangement provides this sloping effect, but the normal line of thinking will be that the turbine will create more resistance analogous to a climb. Here fluid mechanics comes into play.

The first para of this explanation is from an international journal in the results and discussion section. You can verify- file:///D:/cooling%20tower%20journal%20as%20in%20science%20direct.pdf

Abhishek Menon's picture
Abhishek Menon on Apr 3, 2014 6:00 pm GMT
Contrary to what is believed the turbine will actually help in boosting air flow, but ONLY IF THE TURBINE HAS HIGHER SPEED THAN THE DISCHARGED WIND SPEED. This creates a low pressure region in front of the turbine which actually helps the fan's cause. Of course, when generator is loaded, it should be so done that the turbine speed remains greater than the wind discharge.

Here is an analogy that came to my mind. Suppose a vehicle is moving on a level road with the engine producing a fixed amount of power. If the road suddenly slopes, the power requred for the same load will reduce. The turbine and diffuser arrangement provides this sloping effect, but the normal line of thinking will be that the turbine will create more resistance analogous to a climb. Here fluid mechanics comes into play.

The first para of this explanation is from an international journal in the results and discussion section. You can verify- file:///D:/cooling%20tower%20journal%20as%20in%20science%20direct.pdf

Vivian Mascarinhas's picture
Vivian Mascarinhas on May 31, 2014 6:00 pm GMT
Dear Mr. Suresh,

I like your idea. Please let me know how you have tested your idea. I have few ideas of my own that I am planning to develop. If we could team up together, we may be able to come with some working solutions. I am an engineer who has been researching of renewable energy for the past 6-7 years.

Please contact me if you are interested.

regards,

Vivian

Dhrumit Bhatt's picture
Dhrumit Bhatt on Jul 2, 2020 6:52 am GMT

Hey I have similar idea for my final year project...can anyone help me by sharing some knowledge.It would be great if u could help me

Dhrumit Bhatt's picture
Dhrumit Bhatt on Jul 2, 2020 6:54 am GMT

Contact me if u could help me with this.. I'm really searching for someone who cab guide me properly about this.

 

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