Integrated fusion power plant

Abstract

A power conversion system includes a fusion reactor operable to generate a main heat and an auxiliary system operable with the fusion reactor to generate a waste heat. An evaporator operable in response to the receipt of the main heat to convert the working fluid from the liquid form to the superheated vapor form and a generator operable to generate an electrical current. A turbine is coupled to the generator and is operable in response to the receipt of the working fluid in the superheated vapor form to operate the generator and to discharge the working fluid. A condenser is operable to receive the working fluid from the turbine and to condense the working fluid to the liquid form and an auxiliary heater is operable in response to the receipt of the waste heat to preheat the working fluid before it enters the evaporator.

Description

Docket No. 2023PF12322 INTEGRATED FUSION POWER PLANT BACKGROUND

[0001] Power generation, and in particular thermal power generation is an energy conversion process in which energy is generated in the form of heat which is in turn used to drive a thermal cycle such as a Rankine or Brayton cycle. Viable fusion power will require the extraction of heat from a reactor vessel that might be maintained at a vacuum. Thus, there is no heat transfer medium that facilitates the transfer of heat in proposed fusion designs. BRIEF SUMMARY

[0002] In one construction, a power conversion system includes a fusion reactor operable to generate a main heat, an auxiliary system operable with the fusion reactor to generate a waste heat, and an evaporator having an inlet for the input of a working fluid in liquid form and an outlet for the discharge of the working fluid in a superheated vapor form. The evaporator operates in response to the receipt of the main heat to convert the working fluid from the liquid form to the superheated vapor form. A generator operates to generate an electrical current and a turbine is coupled to the generator and operates in response to the receipt of the working fluid in the superheated vapor form to operate the generator and to discharge the working fluid. A condenser is operable to receive the working fluid from the turbine and to condense the working fluid to the liquid form. An auxiliary heater is operable in response to the receipt of the waste heat to preheat the working fluid before it enters the evaporator.

[0003] In another construction, a power conversion system includes a fusion reactor operable to generate a main heat, and an auxiliary system operable with the fusion reactor to generate a waste heat. A compressor is operable to compress a flow of gas, a heat exchanger is operable in response to the receipt of the main heat to heat the flow of gas, and a first generator is operable to generate an electrical current. A turbine is coupled to the first generator and theDocket No. 2023PF12322 compressor and operable in response to the receipt of the heated flow of gas to operate the first generator and the compressor and to discharge the flow of gas as an exhaust gas. A Rankine cycle is operable in response to the receipt of the exhaust gas and the waste heat to operate a second generator. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] To easily identify the discussion of any particular element or act, the most significant digit or digits in a reference number refer to the figure number in which that element is first introduced.

[0005] FIG. 1 schematically illustrates an arrangement of a fusion power conversion system including a Rankine cycle.

[0006] FIG. 2 schematically illustrates the fusion power conversion system of FIG. 1 further including a secondary heating loop.

[0007] FIG. 3 schematically illustrates another arrangement of a fusion power conversion system including a Brayton cycle inclusive of a bottom cycle for energy recovery.

[0008] FIG. 4 schematically illustrates the fusion power conversion system of FIG. 3 further including one or more secondary heating loops. DETAILED DESCRIPTION

[0009] Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in this description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.Docket No. 2023PF12322

[0010] Various technologies that pertain to systems and methods will now be described with reference to the drawings, where like reference numerals represent like elements throughout. The drawings discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way to limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged apparatus. It is to be understood that functionality that is described as being carried out by certain system elements may be performed by multiple elements. Similarly, for instance, an element may be configured to perform functionality that is described as being carried out by multiple elements. The numerous innovative teachings of the present application will be described with reference to exemplary non-limiting embodiments.

[0011] It should be understood that the words or phrases used herein should be construed broadly, unless expressly limited in some examples. For example, the terms “including,” “having,” and “comprising,” as well as derivatives thereof, mean inclusion without limitation. The singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Further, the term “and / or” as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items. The term “or” is inclusive, meaning and / or, unless the context clearly indicates otherwise. The phrases “associated with” and “associated therewith,” as well as derivatives thereof, may mean to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, or the like. Furthermore, while multiple embodiments or constructions may be described herein, any features, methods, steps, components, etc. described with regard to one embodiment are equally applicable to other embodiments absent a specific statement to the contrary.

[0012] Also, terms such as “first”, “second”, “third” and so forth may be used herein to refer to various elements, information, functions, or acts, but should not be considered as limiting in any way. Rather these numeral adjectives are used to distinguish different elements, information, functions or acts from each other. For example, a first element, information, function, or act could be termed a second element, information, function, or act, and, similarly,Docket No. 2023PF12322 a second element, information, function, or act could be termed a first element, information, function, or act, without departing from the scope of the present disclosure.

[0013] In addition, the term “adjacent to” may mean that an element is relatively near to but not in contact with a further element or that the element is in contact with the further portion unless the context clearly indicates otherwise. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Terms “about” or “substantially” or like terms are intended to cover variations in a value that are within normal industry manufacturing tolerances for that dimension. If no industry standard is available, a variation of twenty percent would fall within the meaning of these terms unless otherwise stated.

[0014] FIG. 1 illustrates a power conversion system 100 that includes a nuclear reactor in the form of a fusion reactor 108 that operates as a heat source to power a Rankine cycle 102 which in turn drives a generator 144 to generate electrical power. In the illustrated construction, the fusion reactor 108 is a fusion reactor and preferably an inertially-confined fusion reactor. An inertially-confined fusion reactor is a type of nuclear fusion reactor that utilizes the principle of inertial confinement to achieve controlled fusion reactions. In this design, a target or pellet containing fusion fuel, such as deuterium and tritium or proton-boron, is subjected to intense pulses from lasers (e.g., Neodymium glass (Nd:Glass) lasers) or particle beams. These high- energy beams rapidly compress and heat the target, causing the fusion fuel to reach the necessary conditions for nuclear fusion to occur. As a result, the isotopes of hydrogen, or other fuel fuse together, releasing a vast amount of energy in the form of high-energy particles and radiation. The primary challenge of developing an inertial confined fusion reactor lies in obtaining efficient and sustained fusion reactions, as well as managing the extreme conditions generated during the fusion process. For example, efficiently collecting and transferring heat generated from the fusion reaction will have a great impact on the efficiency of the overall system.

[0015] During the fusion process, energy is released in the form of high-kinetic energy charged particles (e.g., alpha particles). These charged particles are contained within a reactor wall 110 which in turn heats the reactor wall 110. Additional energy may be captured from the small amount of neutron energy that may be liberated during the fusion reaction.Docket No. 2023PF12322

[0016] The inertial confinement within the reactor is supported by one or more lasers 140 that operate as required to initiate the fusion reaction of the fuel within the reactor wall 110. In the illustrated construction, a plurality of lasers 140 (one shown) operate to compress fuel pellets that are periodically introduced into the reactor. Each pellet then goes through a fusion process to release the desired energy with the reactor wall 110 and a portion of that energy, in the form of heat is captured by the reactor wall 110. During this process, each of the lasers 140 generates a significant amount of waste heat 138 that is also captured and utilized as will be discussed below. While this description focuses on the capture of waste heat 138 generated by lasers 140, many other systems or components may generate heat that could be captured and used in much the same way as the waste heat 138 produced by the laser 140. As such, the arrangements disclosed herein are not limited to only capturing waste heat 138 from the lasers 140. Rather, this capture of waste heat 138 should be considered exemplary of other possible systems or arrangements that could capture heat.

[0017] A reactor heat exchanger 142 is in thermal communication with the reactor wall 110 to both cool the reactor wall 110 and to extract the useful heat from the fusion reactor 108. The reactor heat exchanger 142 may be a separate heat exchanger that surrounds the reactor wall 110, may be formed as part of the reactor wall 110, or may be otherwise integrated or partially integrated into the reactor wall 110 to efficiently and effectively extract the heat generated by the nuclear reaction from the reactor wall 110.

[0018] The reactor heat exchanger 142 is part of a primary coolant loop 114 that operates to cool the reactor wall 110 while also providing heat for a Rankine cycle 102, a secondary coolant loop 204, a Brayton cycle 312, or any other cycle or system that can utilize the heat. The primary coolant loop 114 includes the reactor heat exchanger 142, an evaporator 116 or other heat exchanger 206, and a coolant 112. The coolant 112 may include a liquid metal, molten salt, or any other chemical, element, or compound suitable for use in the transfer of large quantities of energy in the form of heat. The primary coolant loop 114 may include a reservoir to allow for the addition, removal, or storage of the coolant 112 as well as a pressure relief or pressure control system that operates to maintain the desired pressures within the primary coolant loop 114. In addition, pumps, valves, compressors, and the like may form part of the primary coolant loop 114 as may be required for the desired operation of the system.Docket No. 2023PF12322

[0019] As illustrated in FIG. 1, the evaporator 116 operates in much the same way as a boiler in a common Rankine cycle. The coolant 112 flows through the hot side of the evaporator and operates to heat a flow of working fluid 134 that flows through the cold side of the evaporator 116. In the illustrated construction, water is used as the working fluid 134 such that the Rankine cycle 102 is a typical steam turbine cycle. Of course, other working fluids (e.g., supercritical carbon dioxide) could be employed and would be selected based on the requirements of the system and the available level of heat at the evaporator 116.

[0020] The primary coolant loop 114 may include additional heat exchangers such as a first reheater 128 and a second reheater 130 as illustrated in the arrangement of FIG. 1. Each reheater 128, 130 operates as a heat exchanger with the coolant 112 passing through the hot side to heat the working fluid 134 that flows through the cool side. Of course, more or fewer reheaters could be employed depending upon the level of heat energy available and the design of the Rankine cycle 102. In addition, the primary coolant loop 114 may include additional sensors, pumps, valves controls, and the like as may be desired to properly operate the primary coolant loop 114.

[0021] The Rankine cycle 102 illustrated in FIG. 1 includes the evaporator 116, a turbine 104, a generator 144, a condenser 124, and a feed pump 126. The turbine 104 may be a single turbine 104 or may include multiple turbines. In the construction illustrated in FIG. 1, the turbine 104 includes an HP turbine 118 (high pressure), an IP turbine 120 (intermediate pressure), and an LP turbine 122 (low pressure) designed to operate using water as the working fluid 134. The HP turbine 118 receives steam produced within the evaporator 116 at a high pressure. Typically, the steam is in a superheated vapor form, however, it could also be saturated steam. After the steam is discharged from the HP turbine 118 where it is expanded to produce rotational energy, it flows to the first reheater 128 where it is reheated to a superheated vapor form or at least a saturated steam form before passing through the IP turbine 120 to extract additional rotational energy. After exiting the IP turbine 120, the steam passes through the second reheater 130 where it is again reheated to a superheated vapor form or a saturated steam form. After passing through the LP turbine 122 where still further rotational energy is extracted, the steam passes through the condenser 124 where it is condensed to a liquid state. The condenser 124 typically uses a flow of cold water or another fluid to cool and condense the steam.Docket No. 2023PF12322

[0022] One or more feed pumps 126 receive the flow of condensed water and operate to pressurize the water and initiate the Rankine cycle 102. A deaerator 146 may be provided to remove any air or other gasses from the flow of liquid. Additionally, one or more feedwater heaters 132 may be provided to preheat the water using steam extracted from various locations within the turbine 104 before the water, in liquid form enters the evaporator 116. In addition, one or more auxiliary heaters 106 or heat exchangers may be provided to further heat the working fluid 134 before it enters the evaporator 116. In the illustrated construction, the auxiliary heater 106 receives waste heat 138 from the lasers 140 which is generated during the process of cooling the lasers 140. The waste heat 138 is conducted to the auxiliary heater 106 using any suitable media (e.g., water).

[0023] The reheaters 128, 130 may be included to improve the efficiency of the Rankine cycle 102. The energy for reheat is taken from the coolant 112 that has energy transferred from the fusion process. As a consequence of the cycle design, there are many different temperature levels of water and / or steam throughout the process that provide unique opportunities to integrate heat from cooling of the lasers 140 and other fusion auxiliary systems. One such example is the heat that can be delivered from cooling of the lasers 140 back to the water / steam cycle at a temperature matched point within the feedwater of the Rankine cycle 102. This can serve as an additional feedwater heater that may allow for a reduction in the number of required feedwater heaters to deliver a given efficiency level or may be an additional stage that improves the overall efficiency.

[0024] The auxiliary systems in the power conversion system 100 contain thermal energy that can be delivered back to the Rankine cycle 102 to enhance the efficiency. The amount of auxiliary power returned to the Rankine cycle 102 is roughly linear with the load of that cycle. By implementing a thermal storage arrangement in the primary coolant loop 114, the injection of that power into the Rankine cycle 102 can be decoupled from its load. While the primary coolant loop 114 is maintained at a constant level, the Rankine cycle 102 load can be varied by charging or discharging the thermal storage.

[0025] The fusion reactor 108 can be operated in such a way that it provides a near steady- state source of thermal energy for the power conversion system 100. In addition, the waste heat generated in the auxiliary systems in the fusion part of the plant may also supply a near continuous source of waste heat 138 that can be recovered for utilization in the energyDocket No. 2023PF12322 conversion process. An example of this is waste heat 138 from the lasers 140. This energy could be stored in some capacity as a thermal store or with a small power conversion device to charge a battery such that this power is available for energy fluctuation management or to keep the power conversion system 100 in a ready-to-run state for support of startup or power fluctuations.

[0026] The fusion reactor 108 could be oversized in such a way that it supports the thermal demand of processes beyond the power conversion to electricity process illustrated in FIG. 1. This could take the form of directly pulling the heat from the fusion part of the plant and delivering it to the end user (e.g., industrial process, thermal energy storage system, hydrolyzer, etc.). An alternative would be for lower energy level requirements to increase the capacity of the power conversion cycle and extract energy at lower levels (e.g., extraction from the Rankine cycle 102).

[0027] One potential drawback of the arrangement of FIG. 1 is the direct interface between the coolant 112 and the working fluid 134 used in the Rankine cycle 102. The power conversion system 200 illustrated in FIG. 2 addresses this concern by utilizing a fusion reactor 108 and a Rankine cycle 102 as described with regard to FIG. 1 along with a primary coolant loop 202 that directly cools the reactor wall 110 and a secondary coolant loop 204 that takes the main heat 148 from the primary coolant loop 202 and delivers it to the evaporator 116.

[0028] As illustrated in FIG. 2, the primary coolant loop 202 includes the reactor heat exchanger 142, a heat exchanger 206, and a primary coolant 208. The reactor heat exchanger 142 is the same as was described with regard to FIG. 1. Additionally, the primary coolant 208 is preferably the same as the coolant 112 described with regard to FIG. 1. Specifically, the primary coolant 208 may include a liquid metal, a molten salt, or any other suitable media.

[0029] The secondary coolant loop 204 interfaces with the Rankine cycle 102 much like the primary coolant loop 114 illustrated and described in FIG. 1. However, rather than receiving the main heat 148 directly from the reactor heat exchanger 142, the secondary coolant loop 204 receives the main heat 148 from the heat exchanger 206. This arrangement provides an extra flow loop between the primary coolant loop 202 that directly cools the fusion reactor 108 and the working fluid 134 that is heated to power the Rankine cycle 102. As with the arrangementDocket No. 2023PF12322 of FIG. 1, the secondary coolant loop 204 provides main heat 148 to the evaporator 116, the first reheater 128, and the second reheater 130.

[0030] The secondary coolant loop 204 includes a secondary coolant 210 that operates to transfer the main heat 148 from the primary coolant 208 to the working fluid 134. The secondary coolant 210 may include water or any other media suitable for the transfer of the main heat 148 and is used to isolate the primary coolant loop 202 from the working fluid loop 136 in the Rankine cycle 102.

[0031] A reservoir, pressure relief mechanism, valves, sensors, pumps, controls, and the like may be provided on the primary coolant loop 114, the primary coolant loop 202, and / or the secondary coolant loop 204 as may be desired to properly operate, monitor, and control the various loops.

[0032] Despite the fact that the fusion reactor 108 is preferably operated to provide a near steady-state supply of thermal energy (main heat 148) for the power conversion system 200, it is possible that there will be fluctuations due to the intermittency of the process. For example, the fuel or pellet injection process is not continuous and may therefore result in small but high frequency power fluctuations. One way to avoid this translating to fluctuations in the power cycle would be to add a thermal storage system between the fusion reactor 108 and the Rankine cycle 102 that dampens these fluctuations to assure that the main heat 148 provided to the Rankine cycle 102 remains constant as if drawn from a constant temperature heat reservoir. The addition of an additional coolant loop as illustrated in FIG. 2 provides some of this damping and may result in a more consistent delivery of main heat 148 to the Rankine cycle 102.

[0033] The fusion reactor 108 is preferably operated at one load point to enhance the stability of the nuclear reaction. However, the power demand for the power conversion system 200 may fluctuate and should therefore be able to operate flexibly to allow the output of the generator 144 to follow the electrical grid. This could be accomplished or enhanced through the addition of an energy storage system that can store excess electrical power when available and discharge that additional power when additional electrical power is required. One such arrangement could include an array of batteries arranged to store electrical energy during periods whenDocket No. 2023PF12322 excess electrical power is available. When sudden load demand occurs, the batteries can quickly discharge excess electrical power without the need to increase the power of the reactor.

[0034] One of the primary coolant loop 202 or the secondary coolant loop 204, but preferably the primary coolant loop 202 may include a storage mechanism for storing a portion of the primary coolant 208 or the secondary coolant 210. The coolant may be stored when the power conversion system 200 doesn’t need all the main heat 148 and can be released into the appropriate coolant loop when the power conversion system 200 load demand surpasses the heat supply of the fusion reactor 108. It should be noted that the storage of coolant could be applied to any coolant loop described herein to achieve the added control or shutdown of the overall system. In particular, for systems that use a liquid metal or a molten salt, the storage may need to include features that maintain the metal in the liquid state or the salt in a molten state even when the reactor and system is shutdown.

[0035] In the arrangement of FIG. 2, this storage arrangement and process could be applied to both the primary coolant loop 202 and the secondary coolant loop 204 to facilitate large and rapid load changes that are not easily accommodated by the fusion reactor 108. For example, when load changes for the fusion reactor 108 cannot be avoided (large and rapid load swings in power demand from the grid) the 2-stage storage system helps to dampen the transient caused by these load swings. The power conversion system 200 can respond very fast as the storage in the secondary coolant loop 204 partially buffers the load swing and the storage provided in the primary coolant loop 202 further dampens the load swing.

[0036] FIG. 3 illustrates a different arrangement of a power conversion system 300 in which the Rankine cycle 102 is replaced by a Brayton cycle 312. With reference to FIG. 3, the power conversion system 300 includes a fusion reactor 108, a primary coolant loop 114, a Brayton cycle 312, and a Rankine cycle 102 (or another bottoming cycle other than water-steam). The fusion reactor 108 is the same as the reactor described with regard to FIG. 1 and includes a reactor wall 110 in which the fusion reaction is contained, a reactor heat exchanger 142 arranged to cool the reactor wall 110 and extract the main heat 148, and one or more lasers 140 arranged to compress the fuel and initiate the fusion reaction.

[0037] The lasers 140 and any other auxiliary systems associated with the fusion reactor 108 may generate waste heat and therefore require cooling. FIG. 3 illustrates one such coolingDocket No. 2023PF12322 arrangement specifically arranged to draw waste heat 138 from the lasers 140. As will be discussed in greater detail, the waste heat 138 may be directed to an auxiliary heater 106 or may follow an alternative use path 314 where the waste heat 138 is directed to the Rankine cycle 102 and used as described with regard to FIG. 1 and FIG. 2 or may be directed to another location as desired.

[0038] The Brayton cycle 312 includes a gas turbine having a compressor 308 and a turbine 310. The compressor 308 operates to draw in working fluid 134 in the form of atmospheric air and compress that air to a desired operating pressure. The compressor 308 is preferably a multi-stage axial flow compressor and may include adjustable guide vanes, interstage cooling and any other features, controls, sensors, valves, and the like that may be available for a compressor 308 of the type used in the Brayton cycle 312.

[0039] The compressed working fluid 134 passes through a cold side of the heat exchanger 306 and is heated by the flow of coolant 112 through a hot side of the heat exchanger 306. The flow rates of the coolant 112 and the working fluid 134 are selected to achieve a desired temperature of the compressed working fluid 134 as it exits the heat exchanger 306. Generally, this temperature corresponds to a desired turbine inlet temperature for the turbine 310. This is similar to the arrangement illustrated in FIG. 1 and FIG. 2 where the various flows and heat exchangers are selected to achieve the desired temperatures at each of the various turbines.

[0040] The turbine 310 preferably includes a plurality of axial flow stages that rotate in response to the flow of high-temperature compressed working fluid 134 therethrough as is well known. The turbine 310 is coupled to the compressor 308 to provide the driving energy for the compressor 308. In addition, a first generator 302 is connected to the turbine 310 and is also driven by the turbine 310 to generate electrical power for delivery to a user such as an electrical grid.

[0041] The turbine 310 exhausts the working fluid 134 at a sufficiently high temperature and pressure to provide heat input for the Rankine cycle 102. The Rankine cycle 102 is a typical Rankine cycle 102 such as the one illustrated in FIG. 1 with the exception that the main heat 148 is provided by the working fluid 134 after it is exhausted from the turbine 310.

[0042] Waste heat 138, such as that collected from the cooling of auxiliary components such as the lasers 140 can be directed to the Rankine cycle 102 and used much like it was describedDocket No. 2023PF12322 with regard to FIG. 1, and much like a conventional combined cycle power plant to drive a second generator 304. Preferably, the waste heat 138 is directed to the working fluid loop 136 and used by the auxiliary heater 106 to preheat the compressed working fluid 134 prior to it entering the heat exchanger 306.

[0043] A bypass valve 212 may be provided to allow for better control of the turbine inlet temperature. Bypassing cool working fluid 134 around the heat exchanger 306 allows for the reduction of the temperature of the working fluid 134 before it enters the turbine 310. By varying this bypass flow, the control system can better control and maintain the desired turbine inlet temperature. A flow control valve 216 may also be provided to allow for the control of flow into the turbine 310. Additionally, a vent valve 214 may be provided to allow for the control of the pressure within the working fluid loop 136 and in particular prior to entry into the turbine 310. Of course, other valves, sensors, controls, pumps, and the like may be used within the Brayton cycle 312 as desired.

[0044] Cooling of the fusion reactor 108 with the coolant 112 provides the necessary heat (the main heat 148) to power the open cycle gas turbine illustrated in FIG. 3. In another arrangement, a different gas turbine cycle such as a closed cycle may be employed. The fusion reactor 108 and its operating parameters are designed in such a way that the coolant 112 provides sufficient heat to power the Brayton cycle 312 as illustrated. Ambient air is used as the working fluid 134 and is compressed and delivered to the heat exchanger 306, which replaces the gas turbine combustion system, to heat the air using the coolant 112. The hot compressed air (working fluid 134) is then delivered to the turbine 310 for expansion and net power generation from the coupled first generator 302. The exhaust energy from the gas turbine could then be the energy source for a water / steam cycle (Rankine cycle 102) thus making this a gas turbine combined cycle concept powered by fusion heat. The water steam cycle (Rankine cycle 102) as part of the combined cycle plant could also use the waste heat 138 from other fusion auxiliary systems including the laser 140 system to improve its efficiency and operation.

[0045] As shown in FIG. 3, three valves may be employed to maintain stable operation of the Brayton cycle 312. The bypass valve 212 can be used, as described above to control a turbine inlet temperature which is an important parameter for turbine power control.Docket No. 2023PF12322

[0046] In addition, if a sudden turbine trip is required, such as may be necessary if the first generator 302 is suddenly unloaded or disconnected from an attached grid, a fast release of the working fluid 134 may be required to avoid overspeed of the turbine 310. The vent valve 214 is provided to quickly allow for the release of the working fluid 134 in these situations.

[0047] The vent valve 214 is selected to open very fast. In addition, to enhance the resilience of the system, a fast-shutting flow control valve 216 may be installed in front of the turbine 310. The flow control valve 216 can be quickly closed to block the flow of working fluid 134 to the turbine 310. Both of the vent valve 214 and the flow control valve 216 are selected to operate at high temperatures (1250°C - 1800°C) and pressures (about 24 bar).

[0048] While not illustrated herein, another arrangement of the power conversion system 300 could employ multiple turbines in place of the turbine 310. Additional heat exchangers could be provided to reheat the working fluid 134, using a portion of the coolant 112 in the primary coolant loop 114, prior to its entry into a second turbine, thereby enhancing the power generated and the efficiency of the Brayton cycle 312 and potentially reducing the size and complexity of the downstream Rankine cycle 102.

[0049] FIG. 4 illustrates another arrangement of a power conversion system 400 that includes the same fusion reactor 108 arrangement of FIG. 3 and the same Brayton cycle 312. However, a secondary coolant loop 204 is positioned between the primary coolant loop 202 and the Brayton cycle 312.

[0050] FIG. 2 illustrates a modification to the arrangement of FIG. 1 that adds the secondary coolant loop 204. FIG. 4 is similar to FIG. 2 in that it adds this secondary coolant loop 204 to the arrangement of FIG. 3. The reactor wall 110 of FIG. 4 is cooled and the main heat 148 is extracted from the reactor wall 110 by the reactor heat exchanger 142 and the primary coolant 208 as described with regard to FIG. 1 through FIG. 3. The secondary coolant loop 204 utilizes the heat exchanger 206 to transfer the main heat 148 from the primary coolant loop 202 to the secondary coolant loop 204. The secondary coolant loop 204 includes a secondary coolant 210 that may be water, liquid metal, molten slats, or any other media that is suitable for transferring the main heat 148 to the heat exchanger 306 at the desired temperature (i.e., a temperature higher than the desired turbine inlet temperature). The Brayton cycle 312, and any associatedDocket No. 2023PF12322 Rankine cycle 102 then operate much as was described with regard to FIG. 3 with the working fluid 134 being heated by the heat exchanger 306.

[0051] As one of ordinary skill in the art will realize, each and every one of the flow loops described herein could include additional components such as reservoirs, storage tanks, pressure relief valves, other valves, pumps, compressors, sensors, controls and the like that may be required or desired to properly operate and control the system and the particular loop that includes the components.

[0052] It should also be noted that the fusion reactor 108 could be oversized, or alternatively the Rankine cycle 102 and / or Brayton cycle 312 could be undersized in a way that allows them to support the thermal demand of processes beyond the power conversion to electricity process. This could take the form of directly pulling the heat from the primary coolant loop 114 and / or from one of the heat exchangers in primary coolant loop 114 or in a secondary coolant loop 204 where used and delivering it to the end user.

[0053] In another construction, a supercritical carbon dioxide (SCO2) cycle may be used in place of or in conjunction with one of the Rankine cycle 102 and / or the Brayton cycle 312.

[0054] Supercritical carbon dioxide (SCO2) is a working fluid that can be used in power generation systems. SCO2 refers to carbon dioxide gas that is brought to a supercritical state, where it exhibits unique properties that make it suitable for power applications. When carbon dioxide is heated and pressurized above its critical point (31°C and 7.38 MPa), it transitions into a supercritical state where it displays properties of both a gas and a liquid. In this state, SCO2 has a high density like a liquid, but it flows like a gas and can efficiently transfer heat. SCO2 offers several advantages over traditional working fluids, such as steam, in power generation. Firstly, it has a higher efficiency due to its higher density, which allows for more compact power generation equipment and reduces energy losses during heat transfer. Secondly, SCO2 has excellent heat transfer properties, enabling effective heat exchange with heat sources and sinks. Additionally, SCO2 can operate at lower temperatures, making it suitable for diverse heat sources, including waste heat or solar energy. By utilizing SCO2 in power generation systems, energy efficiency can be improved, resulting in reduced emissions and increased power generation capacity. The adaptability and potential for integration with various heat sources make SCO2 an attractive option for sustainable and efficient power generation.Docket No. 2023PF12322

[0055] Using SCO2 may not necessarily increase efficiency, but it may allow for more compact turbomachinery which would help with overall plant economics. Also, as the smaller turbines may allow for considerations such as an independent cycle for waste heat recovery or utilizing cascaded cycles for the higher fusion energy recovery process. Finally, SCO2 could be utilized as a coolant in one or more of the coolant loops to efficiently transfer heat between the various loops.

[0056] Although an exemplary embodiment of the present disclosure has been described in detail, those skilled in the art will understand that various changes, substitutions, variations, and improvements disclosed herein may be made without departing from the spirit and scope of the disclosure in its broadest form.

[0057] None of the description in the present application should be read as implying that any particular element, step, act, or function is an essential element, which must be included in the claim scope: the scope of patented subject matter is defined only by the allowed claims. Moreover, none of these claims are intended to invoke a means plus function claim construction unless the exact words "means for" are followed by a participle.

Claims

Docket No. 2023PF12322 CLAIMS What is claimed is:

1. A power conversion system comprising: a fusion reactor operable to generate a main heat; an auxiliary system operable with the fusion reactor to generate a waste heat; an evaporator having an inlet for the input of a working fluid in liquid form and an outlet for the discharge of the working fluid in a superheated vapor form, the evaporator operable in response to the receipt of the main heat to convert the working fluid from the liquid form to the superheated vapor form; a generator operable to generate an electrical current; a turbine coupled to the generator and operable in response to the receipt of the working fluid in the superheated vapor form to operate the generator and to discharge the working fluid; a condenser operable to receive the working fluid from the turbine and to condense the working fluid to the liquid form; and an auxiliary heater operable in response to the receipt of the waste heat to preheat the working fluid before it enters the evaporator.

2. The power conversion system of claim 1, wherein the fusion reactor is a fusion- powered fusion reactor and the auxiliary system includes a plurality of lasers, and wherein the waste heat is generated during the cooling of the plurality of lasers.

3. The power conversion system of claim 2, each of the plurality of lasers includes a water cooling system.

4. The power conversion system of claim 2, wherein the fusion reactor includes a reactor wall that is directly heated by the fusion process within the fusion reactor, the system further comprising a reactor heat exchanger thermally connected to the reactor wall, and a coolant that passes through the reactor heat exchanger to cool the reactor wall and to heat the coolant.

5. The power conversion system of claim 4, wherein the coolant includes one of a molten salt and a molten metal.Docket No. 2023PF12322 6. The power conversion system of claim 2, further comprising a first reheater, wherein the turbine includes a first turbine and a second turbine, and wherein the first reheater receives a portion of the main heat and reheats the working fluid after it is discharged from the first turbine and before it enters the second turbine.

7. The power conversion system of claim 2, further comprising a primary coolant loop and a secondary coolant loop, and wherein the fusion reactor includes a reactor wall that is directly heated by the fusion process within the fusion reactor, the primary coolant loop operable to directly cool the reactor wall and the secondary coolant loop receives the main heat from the primary coolant loop.

8. The power conversion system of claim 2, further comprising a coolant that flows within the primary coolant loop, and wherein the coolant is one of a molten salt and a molten metal.

9. A power conversion system comprising: a fusion reactor operable to generate a main heat; an auxiliary system operable with the fusion reactor to generate a waste heat; a compressor operable to compress a flow of gas; a heat exchanger operable in response to the receipt of the main heat to heat the flow of gas; a first generator operable to generate an electrical current; a turbine coupled to the first generator and the compressor and operable in response to the receipt of the heated flow of gas to operate the first generator and the compressor and to discharge the flow of gas as an exhaust gas; and a Rankine cycle operable in response to the receipt of the exhaust gas and the waste heat to operate a second generator.

10. The power conversion system of claim 9, wherein the fusion reactor is a fusion- powered fusion reactor and the auxiliary system includes a plurality of lasers, and wherein the waste heat is generated during the cooling of the plurality of lasers.

11. The power conversion system of claim 10, each of the plurality of lasers includes a water cooling system.Docket No. 2023PF12322 12. The power conversion system of claim 10, wherein the fusion reactor includes a reactor wall that is directly heated by the fusion process within the fusion reactor, the system further comprising a heat exchanger thermally connected to the reactor wall, and a coolant that passes through the heat exchanger to cool the reactor wall and to heat the coolant.

13. The power conversion system of claim 12, wherein the coolant includes one of a molten salt and a molten metal.

14. The power conversion system of claim 12, further comprising a main heat exchanger that includes a first flow path that receives the coolant and a second flow path that receives the compressed flow of gas from the compressor, the heat exchanger operable to cool the coolant and heat the flow of gas from the compressor.

15. The power conversion system of claim 10, wherein the Rankine cycle includes an evaporator having an inlet for the input of a working fluid in liquid form and an outlet for the discharge of the working fluid in a superheated vapor form, the evaporator operable in response to the receipt of the exhaust gas to convert the working fluid from the liquid form to the superheated vapor form.

16. The power conversion system of claim 15, wherein the Rankine cycle includes an auxiliary heater operable in response to the receipt of the waste heat to preheat the working fluid before it enters the evaporator.

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