Patent Application
20110107774
The present embodiments relate to fans used in refrigeration apparatus such as for example cryogenic food freezers.
Powering a fan in a refrigeration apparatus which utilizes a refrigerant fluid discharged directly into the refrigeration chamber requires use of electricity to operate an electric motor for the fan, the motor being mounted either internally or externally to the refrigeration chamber. Motors consume electrical energy and can add heat to the refrigeration apparatus if they are mounted to or within the refrigeration chamber. Further, internal injection headers required to distribute the refrigerant fluid into the refrigeration chamber consume electricity and produce additional unwanted heat within the chamber.
Such refrigeration apparatus may also have ancillary systems which require electrical energy, such systems to include, but are not limited to, conveying apparatus, thermostat devices, control systems, circulating fans and exhaust fans.
Therefore, what is needed is a fan and/or an injection device for refrigeration apparatus which is capable of converting the mechanical and/or kinetic energy of the refrigerant fluid into electrical energy which can be used to power various ancillary systems or for other purposes, and which is capable of distributing the refrigerant fluid into the refrigeration chamber without the addition of unwanted heat into the chamber.
For a more complete understanding of the present self-powered refrigeration apparatus, reference may be made to the following description of the self-powered refrigeration apparatus and particular embodiments thereof, in conjunction with the following drawings, of which:
The present refrigeration apparatus utilizes internal fans and/or snow injection devices capable of generating electrical energy.
The fan and snow injection device described herein are operable via energy provided by the refrigerant fluid. No motors are necessary to operate the fan or snow injection device. Energy may be removed from the refrigerant fluid by the fan or snow injection device, and that energy may be used to power the refrigeration apparatus. Since the refrigerant fluid provides energy to the fan or snow injection device, the fluid is delivered into the refrigeration apparatus with less energy, which results in a lower pressure of the refrigerant fluid, which in turn results in a greater cooling capacity per pound of refrigerant fluid supplied to the refrigeration apparatus. That is, the transfer of energy from the refrigerant fluid ultimately into electrical energy results in a lower energy state refrigerant fluid which increases the refrigerant capacity of the refrigerant fluid. Accordingly, a 15-20% improvement in refrigeration efficiency is realized by the present embodiments.
Provided is a fan for refrigerant fluid, comprising at least one blade having an internal space therein through which a refrigerant fluid passes; at least one nozzle in fluid communication with the internal space of the at least one blade, wherein the at least one nozzle discharges the refrigerant fluid from the at least one blade at a velocity sufficient to rotate the at least one blade; and an electrical generator operationally connected to the at least one blade. Alternatively, the fan may comprise a plurality of blades. The refrigerant fluid may be flashed into a mixture of solid and gaseous refrigerant as it is discharged from the at least one blade.
Also provided is a snow injection device for a carbon dioxide (CO2) refrigerant fluid comprising a disk having an internal space therein through which a CO2 refrigerant fluid passes; at least one nozzle in communication with the internal space within the disk which discharges the CO2 refrigerant fluid from the disk at a velocity sufficient to rotate the disk, the at least one nozzle being adapted to flash the CO2 refrigerant fluid into gas and solid phases; and an electrical generator operationally connected to the disk. Alternatively, the snow injection device may comprise a plurality of nozzles in communication with the internal space in the disk. The snow injection device may further comprise a shroud operatively associated with the snow injection device for causing the solid phase of the flashed CO2 refrigerant fluid to fall at a reduced velocity out of the device, and into the refrigeration chamber.
The fan and/or snow injection device may further comprise means for storing electricity which are in direct or indirect electrical communication with the electrical generator. The above described nozzles may be high-velocity nozzles, and particularly may be supersonic nozzles.
Referring now to
The blades 18 are engaged with the rotary union 14 such that the rotary union 14 remains stationary as the blades 18 rotate. The internal space 16 may operate as a conduit for the refrigerant fluid 12, or the internal space 16 may be sized and shaped to receive a conduit extending along the fan blade as shown. Such a conduit would be in fluid communication with the pipe 11. The nozzle 20 may be mounted to a tip of the blade 18 and is in fluid communication with the internal space 16 or conduit therein. The nozzle 20 may be a supersonic nozzle and may have its discharge orifice at a right angle with respect to the blade 18. Discharge speeds from the supersonic nozzle may be up to about Mach 3.
As the refrigerant fluid 12 enters the blade 18, it expands and performs work as it moves toward the nozzle 20, forcing the blade 18 to rotate. The nozzle 20 also increases the velocity of the exiting refrigerant fluid and further serves to increase the efficiency of the refrigerator. The refrigerant fluid 12, which may be CO2, can be either a liquid or a gas as it passes through the blade 18, but upon discharge from the nozzle 20 it flashes into a solid and a gas. In certain embodiments, the fan for refrigerant fluid may additionally comprise one or more blades which do not have the internal spaces 16 therein.
The blades 18 may be operationally connected to or engaged with an electrical generator (not shown) which will function as a mechanical brake and will convert the kinetic energy of the rotating blades into electrical energy. The blades, as part of a rotor assembly, may be connected to the electrical generator, via a shaft and gear box. In certain embodiments, the shaft may be a low speed shaft that turns a gear which is adapted to turn a second gear connected to a high-speed shaft at a much faster speed than the low-speed shaft turns. The high-speed shaft turns a generator which is housed within a structure which provides a magnetic field. As the generator turns, the magnetic field is altered, thereby generating electricity.
Accordingly, electrical energy extracted from the rotating blades 18 by the electrical generator can be used directly or can be stored in energy storage devices such as capacitors or batteries to provide electrical energy to the ancillary systems of the refrigeration apparatus or for other purposes. Under testing and load conditions, a single fan 10 has been shown to generate in excess of 1.5 horsepower. As a result, while the fans do not require electrical energy in order to function, they can provide electrical energy for other components of the refrigeration apparatus which is converted from the kinetic energy of the refrigerant fluid. Thus, a refrigeration apparatus which is powered only by the refrigerant fluid may be provided.
For example, but without limitation, the electrical energy generated by the electrical generator may be used to power exhaust fans, conveyor motors, control panels, or other devices associated with the refrigeration apparatus. The electrical energy may be used to power devices or apparatus which are not part of the refrigeration apparatus, or such energy may be sent to the local electrical power grid.
Referring now to
As the CO2 refrigerant fluid 32 enters the disk 38, it expands and performs work as it moves toward the nozzles 40. The nozzles 40 may increase the velocity of the exiting refrigerant fluid and further serve to increase the efficiency of the refrigeration apparatus. The CO2 refrigerant fluid 32 can be either a liquid or a gas as it passes through the disk 38, but upon discharge from the nozzles 40 it flashes into a solid and a gas. As the CO2 refrigerant fluid is discharged from the nozzles 40 at a substantially tangential angle, the disk 38 is caused to rotate. At least one of the nozzles 40 is used to rotate the disk 38.
An electrical generator (not shown) may be disposed between the rotary union 34 and the disk 38, actuated by the rotation of the disk 38 as a rotor for the generator. The disk 38 may be operationally connected to or engaged with an electrical generator (not shown) which will function as a mechanical brake and will convert the kinetic energy of the rotating disk 38 into electrical energy. The disk 38, as part of a rotor assembly, may be connected to the electrical generator, in a manner as discussed with respect to the blades 18 in the embodiments of
Referring now to
The nozzle(s) of the rotating element 58 also increase the velocity of the exiting refrigerant fluid and further serve to increase the efficiency of the refrigerator. The CO2 refrigerant fluid 52 can be either a liquid or a gas as it passes through the rotating element 58, but upon discharge from the rotating element 58 it flashes into a solid and a gas. As the CO2 refrigerant fluid is discharged 62 from the rotating element 58 at a substantially tangential angle with respect to the body of the rotating nozzle 59, the rotating element 58 is caused to rotate.
An electrical generator may be disposed between the rotary union 54 and the rotating element 58, actuated by the rotation of the rotating element 58 as a rotor for the generator. The rotating element 58 may be operationally connected to or engaged with an electrical generator (not shown) which will function as a mechanical brake and will convert the kinetic energy of the rotating element 58 into electrical energy. The rotating element 58, as part of a rotor assembly, may be connected to the electrical generator, as discussed with respect to the embodiments of
The tunnel freezer 100 includes a housing 101 in which a freezing chamber 122 is provided and through which a conveyor 114 powered by a conveyor motor 116 moves to transfer products such as food products through the freezing chamber 122 of the tunnel freezer 100. At least one fan 106 is mounted in the freezing chamber 122. Each of the rotary unions 104 for a respective fan 106 is in fluid communication with a refrigerant conduit 124 which carries the refrigerant fluid 102, such as liquid CO2 from a remote source (not shown). Each of the rotary couplings 104 is in mechanical communication with an electrical generator 108 which harvests the kinetic energy of the rotating fan 106 and converts it into electrical energy. The electrical generators 108 are in electrical communication with an electrical conduit 110 which may transfer the electrical energy, shown generally by arrows 111, generated by the electrical generators 108 to an electricity storage means 112, such as a battery. The electrical energy stored in the storage means 112 may be used to provide electrical energy, shown generally by arrows 113, to an exhaust fan 120, the conveyor motor 116 as shown generally by arrow 115, and/or a control panel 118 as shown generally by arrows 117. The control panel 118 may monitor the operation of the tunnel freezer 100, including the electricity generated by the fan/generator assemblies and the electrical load stored by the storage means 112.
The refrigerant fluid referred to in the above tunnel freezer and fan embodiments may be CO2, nitrogen (N2), or air, each of which may be either in liquid or gas form, or a mixture thereof. Liquid air may be provided as the result of blending or mixing liquid N2 and liquid oxygen (O2).
When liquid CO2 is used as the refrigerant fluid, the fan and disk embodiments discussed above may reduce the pressure of the liquid CO2 before it is discharged from the fan. This reduction in pressure results in a reduction in the energy state of the CO2, which increases the solid to gas proportion of the CO2 when it is discharged from the nozzle(s) of the fan or disk.
It has been shown that the solid proportion of CO2 discharged from the present fan embodiments may be from about 52% to about 57%, whereas traditional, stationary injection devices typically realize a solid proportion of from about 47% to about 48%. Without wishing to be limited by theory, it is believed that when using traditional, stationary injection devices, much of the potential energy contained in the liquid CO2 is converted into heat, which provides 47-48% solid CO2 upon flashing into a lower pressure volume. When utilizing the present fan embodiments, energy is removed from the liquid CO2 in order to perform work to rotate the devices. This results in a decreased pressure of the liquid CO2 which is accompanied by a decrease in temperature. Because the temperature and pressure of the liquid CO2 are lower, about 52-57% solid CO2 is produced upon flashing. Additionally, the energy produced by the rotation of the present fans may be utilized for other purposes. An increased proportion of solid created by the present fans increases the efficiency of a refrigeration system in which the fans are used, because the solid CO2 provides better heat transfer than does the gaseous CO2.
Therefore, a self-powered refrigeration apparatus is provided, comprising a refrigeration chamber and at least one fan, comprising at least one blade having an internal space therein through which a refrigerant fluid passes; at least one nozzle in fluid communication with the internal space within each of the at least one blade, wherein the at least one nozzle discharges the refrigerant fluid into the refrigeration chamber at a velocity sufficient to rotate the at least one blade; and an electrical generator operationally connected to the plurality of blades. Alternatively, the fan may comprise a plurality of blades.
Also provided is a self-powered refrigeration apparatus, comprising a refrigeration chamber and at least one snow injection device, comprising a disk having an internal space therein through which a CO2 refrigerant fluid passes; at least one nozzle in communication with the internal space within the disk which discharges the CO2 refrigerant fluid from the disk at a velocity sufficient to rotate the disk, the at least one nozzle being adapted to flash the CO2 refrigerant fluid into gas and solid phases and eject the gas and solid phases into the refrigeration chamber; and an electrical generator operationally connected to the disk. Alternatively, the snow injection device may comprise a plurality of nozzles.
It will be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the present embodiments as described and claimed herein. It should be understood that the embodiments described above are not only in the alternative, but may be combined.
