Liv, Hall
Wilfred
Liv, Hall
Wilfred
| 1. | Device for conversion of kinetic energy from an external source, e.g. wind or flowing water, into thermal energy, by means of internal friction in a liquid; com¬ prising a pump (2) connected to a shaft (10) receiving kinetic energy from said external source, wherein the pump (2) is provided for pumping the liquid in a circuit (4) comprising a unit (3) for converting the kinetic energy in the liquid into heat, characterized by the unit (3) being a throttle valve (3) which decelerates the liquid in the circuit (3) so that heat is generated, and that the circuit comprising two concentric conduits (32, 33), where a first conduit (33) is located within a second conduit (32), and heated liquid downstream of the throttle valve (3) is conducted in the inner conduit ,(33), and return liquid upstream of the throttle valve is conducted in the outer conduit (32). |
| 2. | Device according to Claim 1, characterized by the two concentric conduits (32, 33) being mutually insulated. |
| 3. | Device according to Claim 1 or 2, characterized by the two concentric conduits (32, 33) being insulated against the environment. |
| 4. | Use of a device according to any one of Claims 13 in connection with personal heating. |
| 5. | Use of a device according to any one of Claims 13 in connection with power supply to boats and ships. |
| 6. | Use of a device according to any one of Claims 13 in connection with heating of persons transported by a full track vehicle. |
| 7. | Use of a device according to any one of Claims 13 in connection with an oven. |
| 8. | Use of a device according to any one of Claims 13 in connection with wind or water power plants. |
| 9. | Use of a device according to any one of Claims 13 in connection with heating, respectively deicing of manhole covers, drains or fire hydrants. |
| 10. | Use of a device according to any one of Claims 13 in connection with pressure reduction systems in water pipes. |
The present invention concerns a device for conversion of kinetic energy to thermal energy by means of internal friction in a liquid, according to the intro- ductory part of claim 1.
Today, there are many heating requirements which can not be solved by means of our common energy sources such as electricity and combustion of fossil fuels. Furthermore, there is a need to utilize the available energy sources so as to not adversely effect the environment as is the case with e.g. combustion of petroleum products or building of huge hydro power plants. Besides, there is a need for better and cheaper exploitation of alternative energy sources such as wind power, wave power, etc., especially for use in small, single installations such as in cabins, in boats, or in homes. This especially applies to use in non-industrial countries having limited capital resources. In emergency situations, e.g. in accidents in the mountains or at the sea, there is a need for personal heating, which today cannot be satisfied in a simple manner. Heating elements using combustion provide a heating that is too concentrated, and also of limited duration. From US 4 271 790 there is known a method and device for heating of water by means of wind energy. Rotational energy from a windmill is transferred to an axle having perforated ribs located in a chamber with a fluid. In the chamber are located further perforated ribs, extending inwardly from the chamber wall and overlapping the axle ribs. When rotation occurs, the liquid is pressed through the perforations, and heat is generated by the internal friction of the liquid. US 4 004 553 discloses a device where one or more elements rotate in a narrow passage in which a liquid flows. By this rotation, a relative movement between the walls of the passage takes place, and heat is developed in the liquid.
US 4 489 678 discloses a device for conversion of mechanical or kinetic energy to heat, where liquid is pumped in a circuit comprising friction generating constrictions, forming an annulus between plate-formed packings and the inner wall of a chamber. These previously known devices for conversion of kinetic energy to heat by means of the internal friction of a liquid are of a comparatively low efficiency. Much of the
heat disappears to the different components from which the devices are build. In order to achieve the best possible efficiency they need to be constructed to very accurate tolerances with the result that manufacturing and marketing becomes so expensive that many potential areas of use are excluded. These known devices are also heavy and are poorly suited for small plants, especially mobile plants.
It is thus an object of the present invention to provide a cheap and simple device for conversion of kinetic energy to thermal energy by means of the internal friction of a liquid.
The object of the invention is achieved by a device having features as stated in the characterizing part of claim 1. Further features are clear from the independent claims.
In the following, the invention will be explained further by means of examples of embodiments and with reference to the enclosed drawings, where
Fig. 1 is a principle sketch of an embodiment according to present invention, where energy is collected from flowing water,
Fig. 2 is an embodiment according to the present invention, for use in personal heating,
Fig. 3 is an embodiment according to the present invention for use by a transport means, shown as a snow-scooter with a sleigh, Fig. 4a and 4b illustrate a combined frying oven which is heated according to present invention,
Fig. 5 a and 5b illustrate a windmill for conversion of wind energy to thermal energy according to present invention, and
Fig. 6 illustrate a tube system for transporting liquid for use in connection with the present invention.
In Fig. 1 there is shown a device, generally denoted 1, for conversion of kinetic energy to heat according to present invention. The device 1 comprises a pump 2 which pumps liquid in a circuit 4. In the circuit 4 are situated one or more prefer¬ ably controllable throtde valves 3. The liquid in the circuit 4 can be choosen accord- ing to the desired end of use; and the liquid which is chosen will, among other things, be dependent upon whether the further energy transfer should be performed directly or indirectly.
In Fig. 1, the circuit 4 comprises an open vessel 5, which for example can be a breeding tank for aquatic organisms. In this case the liquid will therefore be water. The pump 2 receives its energy from water flowing from a reservoir 6 through a tube 7 having a regulator valve 8 to a turbine 9. Rotational energy from the turbine 9 is then transferred to pump 2 through an axle or shaft 10.
When the pump 2 forces water around the circuit 4, the water flow will primarily be decelarated by the throttle valve 3. By means of this decelaration, heat will be generated due to internal thermal friction in the water. This thermal energy will cor¬ respond to the rotational energy of the shaft 10, less the mechanical friction of the pump 2. Thermal energy will result in an increase in the temperature of the water, with the result that the water in tank 5 will be heated.
The embodiment of the present invention shown in Fig. 1 can be used for different purposes within industry, agriculture and in fishfarming; such as by fish farms, plant houses and general heating. This form of heating is also usable in connection with homes, vacation homes etc. The amount of energy from the plant will be in the area of 50 W - 5000 kW. It is assumed that the units to use the thermal energy should not be located far from the energy converter. This is due to the heating loss to a con¬ sumer being proportional to the distance. In Fig. 2 there is shown an example of an embodiment according to present inven- tion, for use in personal heating. This embodiments comprises a propeller 11 which is situated on a rod or support and connected to an energy converter 1 and heating pillow 5. The energy is collected from the wind by the propeller 11 being caused to rotate, and the rotational energy being transferred through a shaft 10 to the device 1 for energy conversion according to the present invention. Also in this case, the device 1 comprises a pump which through a throttle valve (these are not shown), pumps the liquid around circuit 4. The circuit 4 includes the heating pillow 5 where the liquid preferably flows in channels which cover most of the area. Transfer of liquid to the heating pillow must be performed in well insulated tubes, preferably concentric tubes as described above. The heating pillow 5 can be situated against the body and provide heat in an emer¬ gency situation. Typical energy requirements are below 50 W, and this can be achieved with a propeller having a span of about 80 cm. It is possible to mount this
kind of equipment to a rucksack frame, and take it down when there is no need for it.
A similar solution is shown in Fig. 3, where the propeller 11 with the energy con¬ verter 1 is mounted to a snow scooter 13 having a sleigh 14. This is especially suitable for emergency transportation of people suffering from hypothermia in mountain areas. The same equipment can also be mounted for example in boats and other transport means. The power will in this case come from the air resistance due to movement of the transport means. Fig. 4a discloses a frying oven 15 where heating is performed only by rotational energy provided through the shaft 10 to a pump 2. In Fig. 4b this embodiment of the invention is shown in more detail. The pump 2 is connected to an expansion tank 25. The liquid used in this case should be a silicone oil or similar, which can stand high temperatures (200 - 300 °C). The liquid is decelerated by a throttle valve 3 before it enters circuit 4. The circuit 4 is as shown in the figure, divided into three circuits. One of the circuits is connected to a throttle valve 17 and a frying element 18. The other is connected to a throttle valve 19 and to cooking elements 20. The third circuit is directed to a water heater 23 controlled by a thermostat 22 and equipped with a cock 24 for draining of heated water. Furthermore, excess heat can be utilized for the heating of rooms of a dwelling by directing liquid through a valve 21 to a radiator 16.
The system shown in Fig. 4a and 4b provides simultaneous options for frying, cooking, heating of water and heating of a house. Of course, the different parts can also be build separately. The system can be driven by wind power and hydro power. It is especially suited for use in vacation homes, caravans etc. The simple construc- tion of the system and the low total cost from an energy source (for example wind) to consumers, makes it eminently suited for countries which do not have a good electricity supply network.
In Fig. 5a and 5b there is shown a windmill 27 constructed according to the present invention. It comprises a propeller 11 having a vane 26. Through shaft 10, the propeller 11 drives a pump 2 which pumps liquid in the circuit 4, comprising the throttle valve 3. Here a liquid should be used which can stand high temperatures. Utilization of the energy is controlled by a valve 28, which regulates the amount of
heated liquid which is a led to a heat exchanger 29. Heated liquid its taken from the heat exchanger 29 through a metering device 30 to a consumer 31. This system is intended for a plurality of consumers and can be distinguished from other windmill plants by the energy being distributed as heated liquid. It is also easy to imagine that the liquid supplied to a consumer has a certain pressure or kinetic energy, in addition to thermal energy. Pressure of heating energy can be converted at the consumer to further thermal energy by means of local throttle valves. In this manner, the energy conversion will be performed close to the consumer, something which can result in better efficiency and a more simple distribution system. The circuit 4 should not extend for a long distance 4, due to thermal loss to the environment. To reduce this thermal loss as much as possible, warm and cold parts of the circuit 4 (flowing in directions, respectively from and to the throttle valve 3) can be located in two consentric tubes. This is schematically disclosed in Fig. 6 which shows an outer tube 32 and an inner tube 33. Between inner tube 32 and outer tube 33 is shown insulation material 34, which is located so that a tube 32 can lead liquid through an annulus 35 between outer tube 32 and the insulation material 34. Inner tube 33 can transport hot liquid from the throttle valve 33, while tube 32 can transport colder liquid to the valve 33. Also here, the wall between the two circuit parts is of course insulated, but energy utilization will be better than if the warm circuit part is directly to the environment.
The system according to present invention has a number of areas of use, of which some are described herein. A further utilization is is to keep fire hydrants, gullies and tanklids ice-free through the winter. In a fire hydrant, water is under a constant pressure, and part of this water can be heated by being led through a throttle valve. The pump in the circuit will then be the pump creating pressure in the water. At gullies and tank lids, energy can be collected from the wind, or water pressure from an adjacent water conduit.
A further use is to convert energy which today is lost in connection with the pressure reduction systems in water conduits. This water energy can be used for example in the heating of buildings and outdoor plants.