Power generation industry uses a process called Rankine’s cycle to generate majority of electricity via a steam turbines. It requires high temperature to keep the steam pressure up. This project aims to reduce the temperature needed to produce energy, so we can use more of its sources. Making power generation more efficient might seem to be only a small change, but this is the one that affects everything!
Refrigerant-Based power generation, is a patent pending, new approach to power generation. It’s a hybrid of an ordinary power plant and heat pump. It is based on Hydrological Cycle, common in nature thermodynamic cycle. The power plant uses the refrigerant to absorb heat, in the same way as a refrigeration or air conditioning device. And then it converts it into useful power. It does it in a similar way to hydro-power plant build on rivers.
We can use this solution in many areas. The basic installation project we can adapt to different applications. To the temperature of the heat source. The temperature difference between the source and the environment. The potential height of the plant and space for heat exchangers.
We can use the Refrigerant-based power generation either as stand alone technology, or as secondary cycle in Rankine’s plants.
Secondary cycle in power stations
The main application of this method of generating energy is in classic power generation plants based on the Rankine cycle. This plants use high pressure steam to generate electricity. Power plants based on steam boilers are widely used to generate electricity. They mainly use fossil fuels, such as coal, gas or oil as a source of heat. The use of nuclear and solar energy is equally common. The thermal efficiency of these plants varies between 25% and 45%. This means that power plants convert to electricity only a small part of the energy stored in the fuel. Power plants reject most of the useful heat through cooling towers and also lose it in exhaust gases and heat radiation.
The Rankine’s Cycle
In the Rankine’s power plants we run the steam through the turbine and discharge it at relatively high temperature. This might be even 300°C or more. Then we cool down the steam. It turns to water back again so we can pump it back into the boiler. This means that we need to reject large amount of heat from the steam and dispose it off to the environment via cooling tower.
In newly designed power plants, we can use the generation of electric power based on refrigerant as a secondary cycle. We can do this by absorbing heat from the steam condenser and removing the cooling tower. In the case of modernization of existing devices, it can be installed as an additional system by the side of cooling tower or on the cooling tower itself. Hyperboloid cooling towers used for energy production can be up to 200 meters high and up to 100 meters in diameter. That makes a great base for an additional tower that we can built on it and use as a secondary power plant, powered by waste heat and producing electricity without additional fuel needed. And the cooling tower itself can even remain usable.
Advantage of steam power
The great advantage of steam power plants is that they generate a significant temperature difference between the heat source and the environment. This leaves a good design space for the additional system. For the refrigerant-based power generation this means that we can easily pump refrigerant vapours to a great height. This it turn means that liquid refrigerant will generate a huge pressure on turbine inlet.
Better for business
The advantage of this solution is that, with the introduction of a two-stage electric power production system, we can convert more of the heat into electricity and less fuel will be wasted. The refrigerant circuit can be supplied with heat at a lower temperature than superheated steam. We can use it to generate electricity from the heat, that we currently waste on cooling towers. This will increase the amount of energy produced from the fuel unit. It will also reduce the fuel costs needed to produce the required output power. The efficiency increase in this scenario will be directly proportional to economic savings. It will also cause reduction of carbon dioxide emissions and savings in water usage.
Cooling plant for deep mining
Power generation, based on a refrigeration cycle for deep mines, may prove to be the most useful and energy-saving application of this invention. The mining industry is one of the main buyers of electricity. Modern underground mines consume up to thirty percent of electricity to cool tunnels. The temperature of the virgin rocks increases with a depth of about 25-30 °C / km. The deeper the mine is, the harder it gets to pump fresh air into the tunnels. So the deeper the mine, the larger cooling plants we need. And this is only to remove excess heat – a source of energy. This leads to a point where some mines become too deep to be profitable, because mining at too large depths often becomes too difficult and too expensive in relation to the ore value.
Turn mines into power plants.
At this point, energy production based on the refrigeration cycle will be so valuable for this industry. The ore mining process often creates a large number of underground tunnels and other infrastructure elements. The Cooling systems must often cool these first to provide fresh air to the lower sections of the mine.
Hydro-power in mining
The liquid refrigerant will be dropped from the surface level onto hydro-power turbine, installed on the bottom of the mine. It will generate pressure unachievable by any river based power plant. That in turn will generate electricity that can be used for mining process. Liquid refrigerant cooled to surface temperature will cool even more due to energy loss on the turbine. Once cooled the refrigerant will be discharged to the evaporators installed in tunnels, to absorb the heat. Vaporised refrigerant will get back to the surface level driven by gas expansion and surface level cooling and condensation.
If a power plant was installed in these places, the company could save electricity on the refrigeration plant and produce cool air near the works area. It could also use the heat from the virgin rock to generate power for mining equipment. This creates a situation in which the refrigeration installation, its cooling capacity and electric output will increase with the development of the mine and lead to a situation in which, when the extraction of the ore ends, the plant turns into a geo-power plant.
Turn waste heat into power
This application of refrigerant-based power plant will be very similar to the secondary cycle used in power plants. It will use waste heat coming from various industrial processes to generate energy. It will differ mainly in the type of refrigerant and the range of temperatures. The basic concept of this thermodynamic cycle will be applied to many different processes. It only needs enough waste heat to generate electricity on industrial scale. So any large company that uses large cooling towers can use it to generate energy on site and save electricity.
This solution will best work in steel mills, oil refineries, petrochemical and chemical plants, thermal power plants and HVAC systems in skyscrapers. It will support large food processing plants, data centre cooling and many others, including production of electricity from geothermal energy. A specially where we can access hot water to generate energy, but its temperature is too low to use an installation based on a steam turbine.
Power generation for skyscrapers is a separate topic.
Every year more buildings taller than 300 meters is build around the globe. These banks of offices are holding thousands of computer workstations and monitors are equipped with large cooling systems. Industrial scale refrigeration compressors in the basements and large cooling towers on the roofs are keeping all of this equipment cool. Because of height of this buildings we will no need to build any additional tower. We only need to introduce a relatively small modification to buildings a/c system to turn cooling system that wastes energy, into one that produces it.
Cooling the planet through power generation
Refrigerant-based power plant will produce electricity from excess heat stored in the environment. This means that this is the first project to ensure direct cooling of the planet’s atmosphere. This method is based on a natural climatic phenomenon, a hydrological cycle. It is a natural weather process whose thermodynamic principle of operation is responsible for transferring large amounts of water over long distances in the atmosphere. And all this due to small changes in temperature and temperature differences at different altitudes.
The way the air temperature drops with the altitude, we call the temperature lapse. And it is about 9.8°C every thousand meters for dry air and about 5°C for moist air. Many of known refrigerants, has lower temperature lapse than earth’s atmosphere. This means that if we place the refrigerant in a very high column, heated at the bottom to ambient temperature, its vapour at the top of the column will be warmer than the ambient temperature at this height. This in turn allows to cool the vapours and condense the refrigerant on the top of the column, resulting in lifting its mass to a high altitude. This effect we can use to evaporate the refrigerant just like water evaporates and condense it at high altitude. The mass transferred in this way we can drop onto the turbine just like in a hydroelectric plant.
Cooling to below ambient.
The production of electricity by the turbine is accompanied by another phenomenon. The liquid that passes through the turbine reduces in pressure and temperature. This means that the refrigerant cooled to temperature present at a high altitude cools down even more. That only increases its ability to re-absorb heat. In this way, the refrigerant will always absorb more heat at the bottom than release it at the top. Thanks to such a solution, the heat accumulated in the atmosphere will be gradually absorbed and converted into the electric energy. While reducing the demand for power from the grid.
This method of power generation uses the thermodynamic that is very close to Earth’s natural heat distribution system. But it will not just shift the heat around the globe. It will absorb it, acting like a cooling system, and will work efficiently, as long as the size, shape and location of the installation ensures a constant supply of heat.
This does not mean that the location must be hot. Different refrigerants have different boiling points, and some of them are very low. For example the R134a boils in atmospheric pressure in -26°C. This means that it can absorb the heat from anything that is warmer than -26°C. Refrigerant R290 boils in -42°C, and R170 boils in -88°C. This refrigerants we can use even in polar zones and produce electricity out of heat stored in Antarctica. Many other refrigerants have different boiling temperatures suitable for use in different climatic zones. During the design process, engineers can select the type of refrigerant and system operating pressure to match any temperature range on the planet. Including tropics and polar zones.