SYSTEM AND PROCESS FOR TRANSFORMING THERMAL ENERGY INTO KINETIC ENERGY
20200277881 ยท 2020-09-03
Inventors
Cpc classification
F22B3/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01K17/005
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01K21/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01K11/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01K13/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01K7/36
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01K23/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F01K25/10
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F01K27/02
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
Disclosed is a process that combines interacting main processes and sub-processes to extract kinetic energy from thermal energy. These different interacting processes and sub-processes are physically separate from each other with the main processes operating as closed cycles that operate with two different process fluids parallel to each other and interact with each other, in order to consider and utilize sufficiently all three forms of energy, i.e. thermal energy, kinetic energy, and the energy of the phase changes. By interacting, these different main processes and sub-processes enable a combined-process that especially allows the highly efficient transformation of low temperature thermal energy into kinetic energy. Also disclosed is a system for carrying out the process.
Claims
1. A complete process to transfer thermal energy into kinetic energy, the complete process comprising: A) a work process in which a work process fluid circulates in a closed cycle through components of an energy transformation system, wherein in part of the closed cycle the work process fluid is divided such that it flows in two parallel work process streams and in part of the closed cycle the two parallel work process streams are joined and the work process fluid flows in a single combined work process stream; and B) an energy transfer process in which an energy transfer process fluid circulates in a single energy transfer stream in a closed cycle through components of the energy transformation system; wherein, the following four processes are carried out simultaneously for each of the streams: i) for a first work process stream: a) sucking a first specific part of the work process fluid in its liquid state below its boiling temperature out from a reservoir; b) pressurising the first specific part of the work process fluid to a specific pressure which is at least as high as the highest pressure in the following steps of the work process; c) causing the pressurised first specific part of the work process fluid to pass through a first heat exchanger and to receive thermal energy from the energy transfer process fluid of the energy transfer process, wherein the received thermal energy originates from within the energy transfer process; d) causing the pressurised first specific part of the work process fluid to exit the first heat exchanger still in its liquid state but with increased temperature; e) causing the pressurised first specific part of the work process fluid to pass through at least one valve mechanism configured to prevent premature evaporation of the heated work process fluid; f) causing the pressurised first specific part of the work process fluid still in liquid state to enter an expansion chamber of an expander; g) causing the pressurised first specific part of the work process fluid to flash evaporate, thus changing into a gaseous state with a specific pressure inside the expansion chamber, thereby converting at least a part of the thermal energy received in the first heat exchanger into kinetic energy; ii) for a second work process stream: a) sucking a second specific part of the work process fluid in its liquid state below its boiling temperature out from the reservoir; b) pressurising the second specific part of the work process fluid to a specific pressure which is at least as high as the highest pressure in the following steps of the work process; c) causing the pressurised second specific part of the work process fluid to pass through a second heat exchanger and to receive thermal energy from an external energy source; d) causing the pressurised second specific part of the work process fluid to exit the second heat exchanger still in its liquid state but with increased temperature; e) causing the pressurised second specific part of the work process fluid to pass through at least one valve mechanism configured to prevent premature evaporation of the heated work process fluid; f) causing the pressurised second specific part of the work process fluid still in liquid state to enter the expansion chamber of the expander; g) causing the pressurised second specific part of the work process fluid to flash evaporate, thus changing into a gaseous state with a specific pressure inside the expansion chamber, thereby converting at least a part of the thermal energy received in the second heat exchanger from the external energy source into kinetic energy; iii) for the combined work process stream a) causing the evaporated and expanded gas phase of the first and second specific parts of the work process fluid to exit the expander via an outlet mechanism; b) causing the evaporated and expanded gas phase of the first and second specific parts of the work process fluid to flow from the outlet mechanism into a third heat exchanger and to exchange thermal energy with colder energy transfer process fluid in the energy transfer process; c) causing the first and second specific parts of the work process fluid to exit the third heat exchanger in the liquid state at their lowest temperature and pressure in the work process; d) causing the first and second specific parts of the work process fluid to enter the reservoir; iv) for the energy transfer stream; a) causing energy transfer process fluid in the gaseous state at its lowest temperature to enter the third heat exchanger in the energy transfer stream and to exchange thermal energy with work process fluid at a higher temperature in the combined work process stream; b) causing the energy transfer process fluid in the gaseous state to be sucked out of the third heat exchanger with its temperature elevated by absorption of the condensation energy of the work process fluid; c) causing the energy transfer process fluid to be pressurized, thereby further increasing its temperature; d) causing the energy transfer process fluid to enter the first heat exchanger at its highest temperature in the energy transfer stream and to exchange thermal energy with colder liquid phase work process fluid of the first work process stream; e) causing the cooled energy transfer process fluid still in the gaseous state to exit the third heat exchanger; f) causing the cooled energy transfer process fluid still in the gaseous state to go through a decompression step, thereby further decreasing the temperature of the energy transfer process fluid, by passing through a section of a conduit wherein the cross section of the conduit is increasing; v) cyclically repeating the steps of paths i) to iv).
2. The process according to claim 1, wherein the energy transfer process receives all of the freed energy of the condensation of the process fluid of the work process.
3. The process according to claim 1, wherein the energy transfer process transfers all of the freed energy of the condensation of the process fluid of the work process back into the work process.
4. The process according to claim 1 wherein the first work process stream and the second work process stream share the same valve mechanism and pass through the valve mechanism to the expansion chamber of the expander together.
5. The process according to claim 1, wherein at least one additional heat exchanger further cools the energy transfer process fluid after the energy transfer fluid passes through the first heat exchanger by transferring thermal energy from the energy transfer process fluid to at least one process fluid flowing in at least one process external to the work process and energy transfer process of the complete process.
6. The process according to claim 1, wherein at least one additional expander decreases further the remaining pressure of the energy transfer process fluid after the energy transfer fluid passes through the first heat exchanger thus transforming at least a part of the pressure into available kinetic energy at the mechanical outlet of the additional expander.
7. The system for carrying out the complete process of claim 1 for transferring thermal energy into kinetic energy, the system comprising the following components: a) reservoir comprising liquid work process fluid; b) a first pump; c) a first heat exchanger; d) at least one valve mechanism; e) an expansion chamber of an expander f) conduits connecting components a) to e) to comprise a path for work process fluid of a first work process stream from the reservoir to the expander; g) a second pump h) a second heat exchanger i) conduits connecting components a), g), h), d), and e) to comprise a path for work process fluid of a second work process stream from the reservoir to the expander; j) an outlet mechanism; k) a third heat exchanger; l) conduits connecting components e), j), k), and a) to comprise a path for work process fluid of a combined work process stream from the expander to the reservoir; m) a compressor; and n) conduits connecting the third heat exchanger to the compressor, the compressor to the first heat exchanger, and the first heat exchanger to the third heat exchanger to comprise a closed path for energy transfer process fluid of an energy transfer stream.
8. The system according to claim 7, wherein at least one additional heat exchanger further cools the energy transfer process fluid after the energy transfer fluid passes through the first heat exchanger by transferring thermal energy from the energy transfer process fluid to at least one process fluid that flows in at least one process external to the work process and energy transfer process of the complete process.
9. The system according to claim 7, comprising at least one additional heat exchanger in the energy transfer stream, that is configured to further cool the energy transfer process fluid after the energy transfer fluid passes through the first heat exchanger by transferring thermal energy from the energy transfer process fluid to at least one process fluid carrying thermal energy from an external energy source that flows into a heat exchanger situated before the second heat exchanger thus increasing the temperature of the at least one process fluid carrying thermal energy from the external energy source before it reaches the second heat exchanger.
10. The system according to claim 7, comprising at least one additional expander in the energy transfer stream, that is configured to decrease the pressure of the energy transfer process fluid after the energy transfer fluid passes through the first heat exchanger thus transforming at least a part of the pressure into available kinetic energy at the drive shaft of the expander.
11. The system according to claim 7, wherein the first work process stream and the second work process stream share the same valve mechanism and pass through the valve mechanism to the expansion chamber of the expander together.
12. The system according to claim 7, wherein the valve mechanism before the expander is configured to operate in a clocked fashion to prevent premature evaporation of the work process fluid before it enters the expander.
13. The system according to claim 7, wherein the valve mechanism before the expander is configured as a lock mechanism to prevent premature evaporation of the work process fluid before it enters the expander.
14. The system according to claim 7, wherein the valve mechanism before the expander is configured as a metering mechanism to prevent premature evaporation of the work process fluid before it enters the expander and to allow exactly metered amounts of the work process fluid to be released into the expansion chamber.
15. The system according to claim 14, wherein the metering mechanism is a metering rotating valve mechanism.
16. The system according to claim 7, wherein at least one of the pumps or the compressor are connected to the expander either by a direct or indirect mechanical, hydraulic, pneumatic, or electrical connection in a way that at least a part of the kinetic energy provided by a mechanical outlet of the expander at least partly provides the necessary kinetic energy for operation of the at least one of the pumps or compressors.
17. The system according to claim 10, wherein at least one of the pumps or the compressor of the system is connected to the additional expander in the energy transfer stream either by a direct or indirect mechanical, hydraulic, pneumatic, or electrical connection in a way that at least a part of the kinetic energy provided by a mechanical outlet of the additional expander of the energy transfer stream process at least partly provides the necessary kinetic energy for operation of the at least one of the pumps or compressors.
18. The system according to claim 7, wherein the speed of the work process and the energy transfer process can be adjusted relative to each other, with a different relative speed of the pumps of the work process compared to the compressor of the energy transfer process.
19. The system according to claim 7, wherein the cross section of the components through which the process fluids are moving are configured in such a way that the flow speeds and flow pattern of the process fluids at specific locations at which thermal energy in the process fluids is either increased or decreased, thereby changing the temperature of the process fluids, are optimised and thus energy losses reduced.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0096] The present invention combines interacting main processes and sub-processes to extract kinetic energy from thermal energy. These different interacting processes and sub-processes are physically separate from each other with the main processes operating as closed cycles that operate with two different process fluids parallel to each other and interact with each other, in order to consider and utilize sufficiently all three forms of energy, i.e. thermal energy, kinetic energy, and the energy of the phase changes. By interacting, these different main processes and sub-processes enable a combined-process that especially allows the highly efficient transformation of low temperature thermal energy into kinetic energy. Unique and outstanding features of the combined process of the invention are an artificial heat sink, the recovery and conservation of the condensation enthalpy in one of the sub-processes, and keeping all thermal energy inside the combined process. With the combined process even sub-zero temperatures can be used with high efficiency as heat sources. Additionally, the independence of the overall efficiency of transforming thermal energy into kinetic energy from the operating temperatures is significantly increased. For energy conservation and the environment the advantages of this invention are great.
[0097] In its minimal form that ensures that it can work orderly the process of the invention is comprised of two main processes that define separate streams for transferring energy that both operate as closed cycles parallel to each other. All processes together are referred to as the complete process. The following description and figures show for each component, part, process, or sub-process only the required minimum number that can allow orderly operation of the system.
[0098] It is always possible to increase the number of functional components, or streams and let those work in parallel in a similar way that, for example, in a piston engine several cylinders, pistons, or the number of valves or spark plugs per cylinder could be increased; all nevertheless still operating under the same principle, which would be described only with the minimum number of each item necessary for complete functionality.
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[0100]
[0101] In the embodiment shown in
[0102]
[0103] In heat exchanger (43) the pressurised, liquid, cold work stream process fluid is pressed forward by pump (42) and is heated up by the gaseous hot process fluid of the parallel operating energy transfer process (120) that will be described herein below. Heat exchanger (43) transfers thermal energy into the work stream process fluid from the energy transfer stream process fluid that enters heat exchanger (43) in the most efficient form from the opposite side. To this end the energy transfer stream process fluid was heated up and the liquid work stream process fluid has at its entrance to heat exchanger (43) still its coldest temperature in the first work stream.
[0104] In nearly all but some extreme cases the first of the two parallel work streams is heated to a much higher temperature than the second of the two parallel work streams. The pressure applied by pump (42) prevents this specific part of the work stream process fluid from starting to evaporate after being heated in heat exchanger (43). The energy that is transferred in heat exchanger (43) from the energy transfer stream process fluid into the work stream process fluid corresponds to the energy that is transferred during the condensation process into the energy transfer stream process fluid.
[0105] The work stream process fluid has the highest temperature it can reach in the first work stream (150) at this point when leaving heat-exchanger (43) before entering the valve mechanism (45).
[0106] The valve mechanism (45) has the main task of preventing the overheated, pressurised work stream process fluid from evaporation before it is inside the expansion-chamber (46) of the expander. The valve mechanism (45) also controls the flow-speed of the work stream process fluid in order to prevent a part of the hot work stream process fluid to increase speed and prematurely start evaporating. An advantageous way to realise controlling valve (45) is by using it as a lock system that disrupts fluid communication between the amount of work stream process fluid that is entering the expansion chamber (46) of the expander and the work stream process fluid that is still before valve mechanism (45). Another advantageous embodiment of the valve mechanism (45) is a metering mechanism, e.g. a rotating valve mechanism. If valve mechanism (45) causes a clocked or pulsed performance this would not pose any disadvantage for the process. For orderly operation the valve mechanism (45) and pump (42) need to be adjusted to or harmonised with each other.
[0107] When the overheated, pressurised work stream process fluid passes through the valve mechanism (45) and enters the expansion chamber (46) it immediately flash evaporates due to the increased cross section of the expansion chamber (46). The expander can be any kind of expander that either works with positive replacement or a fluid mechanical mechanism to generate a movement from the pressure difference of the flash work stream process fluid at the entrance and the exit of the expansion chamber (46). An advantageous embodiment of the expansion chamber is an engine that operates with positive replacement and can handle condensation and the formation of drops inside the expansion chamber. It is also possible to use a pre-chamber for the flash-evaporation as is known from turbines that work with super-critical steam. For the complete-process (100) the design of the expansion chamber (46) is not important.
[0108] During the flash evaporation in the expansion chamber (46) the overheated, pressurised work stream process fluid of both parallel work streams of the work process (110) consumes a specific amount of thermal energy to enable the phase change from the liquid state to the gaseous state and the temperature of the work stream process fluid drops to a lower temperature. In most cases this energy consumed for the phase change will be the largest part of the thermal energy contained in the work stream process fluid. The remaining thermal energy of the now gaseous work stream process fluid applies a certain pressure in the expansion chamber that is then converted to kinetic energy. In
[0109] When the work stream process fluid is expanding, thus converting thermal energy into kinetic energy, and has reached the furthest point in expansion chamber (46), an outlet mechanism (48) connects the now expanded gaseous work stream process fluid to the following condenser (49). The outlet mechanism from the expansion chamber (48) to the condenser (49) can be an opening, a special valve or an outlet mechanism as described in patent application WO/2013072913 A1 to the inventor of the present invention.
[0110] The condenser (49) works as a heat exchanger. One medium is the work stream process fluid that circulates in the closed work process (110). The other medium going through heat exchanger (49) is the gas of the other closed main process, i.e. the energy transfer process (120). When entering heat exchanger (49) the gas of the energy transfer process (120) is significantly colder than the work stream process fluid.
[0111] The main task of the heat-exchanger (49) is to transfer energy from the expanded work stream process fluid to the energy transfer stream process fluid so that the work stream process fluid condenses and turns into its liquid state. The energy that has to be removed from the work stream process fluid to bring about the complete condensation of the work stream process fluid leads to a decrease of temperature of the work stream process fluid and an increase of temperature of the energy transfer stream process fluid.
[0112] The cooled, liquid unpressurised work stream process fluid flows then from the condenser (49) to the reservoir (41) and the same cycle for the first work stream (150) is repeated.
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[0114] As can be seen in
[0115] The work stream process fluid of the second work stream (140) is heated without evaporating in heat exchanger (53) and released through a special valve mechanism (45) into the expansion chamber (46) of the expander. The work stream process fluid of the second work stream (140) flash evaporates only in the expansion chamber (46). In the embodiment shown in
[0116] Both, the first work stream and the second work stream move separated and parallel to each other until each stream has passed through its first heat exchanger. For the first work stream this is heat exchanger (43) for the second work stream this is heat exchanger (53). After they have each passed their respective first heat exchanger, both streams can be merged into one stream at any given point until the work stream process fluid flash evaporates and changes from the liquid phase into the gas phase inside the expansion chamber (46). It is technically advantageous if both partial streams of the work-stream meet before the valve mechanism (45) because then only one single valve mechanism is required. Otherwise this does not change the complete process (100) and/or the work process (110).
[0117] By splitting the work stream (110) into two parallel partial streams, it is possible to heat them independently and parallel to each other. The first work stream (150) receives the energy of the condensation of the work stream process fluid and thus keeps this energy inside the complete process (100). For the energy balance of the complete process (100) and for its efficiency this is of great importance. The second work stream (140) receives the external thermal energy that is introduced into the system from outside. By transferring the energy in parallel and not sequential or successively, both the first and second work processes can receive the complete amount of energy that is supposed to be transferred to each of them. Both parallel partial streams have at the beginning of the transfer of energy their lowest temperature in the work process (110) and the complete process (100), thus providing the ability to use the maximum temperature difference for the transfer of thermal energy.
[0118] Because the evaporation is not supposed to happen before either of the first or second work streams have reached the expansion chamber (46), it is possible that either one or both of them reach a temperature where the work stream process fluid is in a super-critical state. This has no process changing influence, neither on the task of the work process nor on the complete process.
[0119] Both parallel work streams mix with each other after they have received energy respectively in the heat exchangers (43) and (53). This mixing of both parallel work streams will lead to an average temperature that is lower than the temperature of the stream that had the higher temperature. However, this does not lead to a loss of energy because the combined streams still contain the exact same amount of energy (e.g. in kilo Joule) as the sum of the two parallel partial streams.
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[0121] The energy transfer stream uses a gas, e.g. carbon-dioxide and methane, as a medium referred to as the energy transfer stream process fluid. The main task out of several tasks of the energy transfer stream is to keep the energy which is extracted during condensation of the work stream process fluid inside the complete process. To this end the energy transfer stream process fluid streams into heat exchanger (49) with the coldest temperature the energy transfer stream process fluid has during the energy transfer process. In heat exchanger (49) thermal energy plus the energy related to the condensation is transferred from the nearly completely expanded work stream process fluid in its gaseous state with a temperature close to its condensation temperature into the energy transfer stream process fluid that has at the entrance of heat exchanger (49) its lowest temperature and its lowest pressure within the energy transfer stream. The energy transfer stream process fluid thus increases its temperature inside heat-exchanger (49) by the energy extracted from the work stream process fluid that is the second stream in heat-exchanger (49) and in turn the work stream process fluid condenses as a result of the extraction of energy.
[0122] When the energy transfer stream process fluid is extracting energy from the condensation of the work stream process fluid in heat exchanger (49) the energy related to the condensation of the work stream process fluid is transferred to the energy transfer stream process fluid at a low temperature level compared to the temperatures at other points of the complete process. The amount of the energy transfer stream process fluid has to be chosen accordingly to be able to absorb this energy in the form of thermal energy. The most advantageous amount of the energy transfer stream process fluid in the energy transfer stream is therefore determined by the ability to absorb the total energy freed during the condensation of the work stream process fluid. The energy that needs to be absorbed expressed in kilo Joule divided by the possible temperature increase in degrees Kelvin by the following compression in compressor (72), the heat capacity of the specific energy transfer stream process fluid at the different chosen temperatures, and relative flow speed of the energy transfer stream process fluid compared to the flow speed of the work stream process fluid gives the minimum mass and thus the minimum amount of gas that is needed for the energy transfer stream in order to be able to extract all of the energy related to the condensation from the work-stream. Several sample calculations herein below will explain this in more details.
[0123] Heat-exchanger (49) is followed in the energy transfer stream by compressor (72). The heated energy transfer stream process fluid is sucked into and compressed by compressor (72) to higher pressure and higher temperature.
[0124] Compressing the energy transfer stream process fluid in compressor (72) to a specific higher temperature allows then, in a following step, the transfer of this energy from the condensation back through heat exchanger (43) into the work stream process fluid in the first work stream (150). The thermal energy transferred from the energy transfer stream process fluid to the first work stream at heat exchanger (43) is used in the work stream (110) to support the evaporation of the complete work stream process fluid not just the process fluid of the first work stream. According to the amount of energy that needs to be transferred, the temperature of the energy transfer stream process fluid after compressor (72) needs to be sufficiently high enough to enable the transfer of a sufficient amount of thermal energy into the work stream process fluid of the first work stream (150). The exact temperature increase that the energy transfer stream process fluid needs to reach in compressor (72) is given by the amount of energy that needs to be transferred in kilo Joule, divided by the mass per time and the specific heat capacity of the energy transfer stream process fluid and the relative flow speed of the energy transfer stream process fluid compared with the flow speed of the work stream process fluid.
[0125] This step of elevating the energy of the condensation extracted from the work stream process fluid to a higher temperature level by compressing the energy transfer stream process fluid is only possible in a separate process and also only with a different process fluid than those of the work stream.
[0126] Leaving compressor (72) the pressurised and hot energy transfer stream process fluid enters the heat-exchanger (43). After the compression the energy transfer stream process fluid has at this location its highest temperature in the energy transfer stream. Inside heat exchanger (43) the pressurised and hot energy transfer stream process fluid exchanges thermal energy with the pressurised liquid work stream process fluid which enters heat exchanger (43) at its coldest temperature in the first work stream. Both the work stream process fluid and the energy transfer stream process fluid exchange thermal energy, thereby increasing the temperature of the work stream process fluid and lowering accordingly the temperature of the energy transfer stream process fluid.
[0127] The now cooler energy transfer stream process fluid leaves heat exchanger (43) and streams either directly to heat exchanger (49) or in other embodiments through one or several additional heat exchangers or through one or several additional expanders.
[0128] In case that instead of an oxidiser or fuel gas for a burner another medium is used as source of external thermal energy, especially a source with relative low temperature, thermal energy can be transferred from the additional heat exchanger (83) to an optional additional heat exchanger (86) in the incoming stream of external energy (see
[0129] In other embodiments the now cooler energy transfer stream process fluid leaves heat exchanger (43) and streams through at least one additional expander (85), where at least part of the remaining energy in form of the remaining pressure of the pressurised energy transfer stream process fluid is converted to kinetic energy at the mechanical outlet of the expander that can be used, e.g. in the complete process (100) or parts of it, e.g. compressor (72).
[0130] In other embodiments at least one additional heat exchanger (83) and together at least one additional expander (85) are used in at least one of the energy transfer stream processes.
[0131] Cooling the energy transfer stream process fluid also decreases its pressure. It is therefore advantageous to increase and/or decrease accordingly the cross sections of the paths, for example pipes, in the system followed by the energy transfer stream process fluid in order to keep pressure losses at a minimum. After the energy transfer stream process fluid has passed through heat exchanger (43) (and optionally) additional heat exchangers (83), (84), and/or expander (85), or additional expanders, the energy transfer stream process fluid arrives at the entrance of heat exchanger (49). At the entrance of heat exchanger (49) the energy transfer stream process fluid is going through a decompression. By increasing the cross section of the path ((117), (127), and 137) in
[0132] Through the suction that comes from the compressor (72) located in the heat transfer stream (120) right after the heat exchanger (49) the energy transfer stream process fluid is moved through heat exchanger (49) and does therefore not require a remaining pressure to overcome the streaming resistance inside heat exchanger (49). The rapid cooling to a very low temperature constitutes an artificial heat sink in the complete process (100). As opposed to prior art systems, especially those based on the conventional single-medium-process in use since the year 1784 until today, utilize the surroundings, i.e. either the air or some water-body, as the point with the lowest temperature the present invention has its own controllable heat sink as an integral part of the complete process.
[0133] Like in other cryo-aggregates or cooling devices, the temperature of the heat sink can be chosen to be significantly below ambient temperature, thus creating a temperature difference between the ambient temperature and the lowest temperature within the complete process that can even be used to generate kinetic energy from a source of external thermal energy with ambient temperature of the surroundings. This is even possible if the surrounding ambient temperature is a sub-zero temperature. For such applications both process fluids have to be chosen with the right boiling temperature and the complete process/system needs to be realised with sufficient thermal insulation. Sample calculations herein below show such an example.
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[0136] In cases where the external energy that is introduced into the complete process raises the temperature of the second work stream (140) significantly higher at heat exchanger (53) than the temperature that the first work stream (150) reaches after heat exchanger (43) it would be possible to let the first work stream and the second work stream meet directly at heat exchanger (53). Then the already heated first work stream would be further heated directly by the external energy at heat exchanger (53). The same result could also be achieved by dividing heat exchanger (53) into two regions where the higher temperature region is used by the first work stream (150) and the lower temperature region is used by the second work stream (140). However, from an energetic point of view it makes no difference where the energy is transferred or whether the energy is transferred into the complete process (100) through the first or the second work stream or through both. At the end both streams will eventually mix, either right after the heat exchangers (53) and (43) or at the latest inside expansion chamber (46). Then the two parallel streams of the work stream process fluid will mix together and thus reach a balance between the different temperature levels of thermal energy. What counts for the efficiency of the complete process is how much energy is introduced into the expansion chamber (46), the different temperatures of the two parallel work streams, however, are not important. The simplest solution, which is shown in
[0137] It could also be advantageous to mechanically connect the expansion chamber (46) with at least one of the pumps (42), (51) and compressor (72) in order to utilize part of the energy output from the expander to operate these components. Additionally the pumps and compressors could be driven by electro-motors receiving their energy from a generator that is connected to the expander; this would also allow operating the different pumps and the compressor at different rotational speeds. The optional additional expander (85) (see
[0138] The external energy can be introduced into the system in many ways, not unlike can be done with existing systems today. The external thermal energy can be generated in a burner through any kind of combustion, it can be introduced through a medium with thermal external energy that transfers its thermal energy through heat exchanger (53) into the work stream process fluid, it can be solar generated thermal energy, it can be heat-radiation, or any other kind of radiation able to introduce energy that does not even need to be thermal energy into the process or system or any other method to introduce thermal energy into heat exchanger (53). For the function of the complete process of this invention itself, the way how the external thermal energy is introduced from outside is not important.
Sample Calculations
[0139] Comparing the conventional single-medium-processes with this invention based on the relevant calculations of the different energy streams involved, in the form of several simple small tables revealing temperatures and energies at various locations in the system, makes the innovative step, the purpose, and the technological benefit of this invention very clear and easy to understand.
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[0141] The different energies in
[0142] In
[0143] In
[0144] The only part of the introduced external energy, referred to as primary energy (21) that can be changed into kinetic energy in the conventional single-medium-process is the part that is shown at (24). It cannot reach more than 42% of the energy put into the system of the conventional single-medium-process. This energy is herein in
[0145]
[0146] At heat exchanger (49) the condensation is started by extracting thermal energy (114). In contrast to the conventional single-medium-process in which the condensation of the medium is done using an external source of coolant, in the present invention condensation of the work stream process fluid is done with the energy transfer stream process fluid. By transferring the energy of the condensation into the energy transfer process (120) the energy of the condensation, shown at (115), can be kept in the complete system. Because this energy is not useful for the process on such a low temperature level, compressor (72) elevates the temperature, shown at (116), so it can be used in heat exchanger (43). The tables (115) and (116) show the difference in temperature. In both tables the temperature is also shown in degrees Kelvin. This is relevant because the temperature from the stream before compressor (72) and afterwards (116) needs to be increased in the example of
[0147] The compressed energy transfer stream process fluid is at a sufficient high temperature level (116) after the compression at compressor (72) to transfer all the energy that was recovered from the condensation in heat exchanger (49) to the first work stream (150) through heat exchanger (43). The energy that is needed for compressor (72) has to be taken from the primary kinetic energy at (113). Also the energy needed for the pumps (42) and (51) needs to be taken from the primary energy at (113). It is therefore an advantageous embodiment to connect the compressor and/or one or both pumps with the energy output of expander (47). This connection can be in form of a mechanical connection, like a common shaft, also other ways of connection are possible, like hydraulic, pneumatic, or electrical, etc.
[0148] Another advantage of the present invention over the prior art, besides recovering the energy of the phase change, is the lower temperature that allows more energy to be extracted at heat exchanger (53) from the external energy source. In the conventional single-medium-process the process medium, usually water, is condensed at ambient temperature of the medium, e.g. an air or a water body, outside the system. Therefore the temperature of the process fluid in the conventional single-medium-process streaming in
[0149] As can be seen in
[0150]
[0151]
[0152] The additional energy fed by the first stream shown at (128) is the recovered energy of the condensation (125) after heat exchanger (49). The energy for the compressor (72) and the pumps (42) and (51) has to be subtracted from the primary kinetic energy (123).
[0153] The temperature difference of the energy transfer stream process fluid before the compressor (72) shown at (125) and after it shown at (126) can be seen as 436 Centigrade or as a 2.17 times increase of absolute temperature. This is much lower than in a conventional Diesel engine in respect of pressure and temperature.
[0154] A more extreme example is shown in
[0155] The process fluid of the work stream in this specific case needs to have a boiling point at or below minus 40 Centigrade. In this extreme example of
[0156] At heat exchanger (53) the external energy is transferred to a much colder second work stream (140) with a temperature of minus 40 Centigrade. This leads than to a temperature of the second work stream of minus 10 Centigrade, shown at (131). The first work stream (150) comes with a temperature of plus 112.3 Centigrade out of heat exchanger (43), shown at (138). Both parallel work streams mix and enter the expander (46) with a temperature of plus 51.2 Centigrade (132). The work stream process fluid flash evaporates in expander (46). By evaporating most of the thermal energy is consumed by the phase change from the liquid phase to the gaseous state. The amount of energy that is delivered by the first work stream has at best the temperature and thus the thermal energy that corresponds with the amount of energy needed for the phase change. When the work stream process fluid evaporates and expands inside the expander (46) it converts a certain amount of thermal energy into primary kinetic energy (133). With its remaining thermal energy the gaseous work stream process fluid leaves the expander (46) expanded and colder than it entered at a temperature of minus 36 Centigrade (134). There the colder and expanded gaseous work stream process fluid condenses and heat exchanger (49) transfers the energy of the condensation plus the remaining thermal energy to the energy transfer stream process fluid, which in this case is a gas with a sufficiently low boiling point, for example carbon-dioxide or methane.
[0157] In
[0158] Such a system needs good thermal insulation in order to keep heat losses small. The amount of energy from the low external temperature thermal energy that is available to be converted to kinetic energy is in this process at 80% very high. Thermal and mechanical losses need to be subtracted. Because the amount of energy per kilogram is at this temperature range rather small, the losses of the compressors, pumps, and the expander are relative to the primary energy higher than they would be at higher temperature ranges.
[0159] The calculations made in the three examples in
[0160] As can be understood from the description and the calculations the main advantages of keeping the significant amount of energy of the phase change within the system are only made possible: [0161] firstly by splitting the work process part that receives energy from outside the system to enable parallel partial heating processes using both the external thermal energy and the energy recovered from the condensation; and [0162] secondly by keeping the energy of the phase change in the system the reachable process efficiencies in all temperature ranges are significantly higher than in any other processes known today.
[0163] Although embodiments of the invention have been described by way of illustration, it will be understood that the invention may be carried out with many variations, modifications, and adaptations, without exceeding the scope of the claims.