WO2025262157A1

WO2025262157A1 - Modular power generation island for interconnection with a source of thermal energy

Info

Publication number: WO2025262157A1
Application number: PCT/EP2025/067146
Authority: WO
Inventors: Gianluca BARTOLINI; Marco Fiori; Gianni ORSI; Paola Di Festa; Davide BILIOTTI
Original assignee: Nuovo Pignone Technologie SRL
Current assignee: Nuovo Pignone Technologie SRL
Priority date: 2024-06-18
Filing date: 2025-06-18
Publication date: 2025-12-26
Anticipated expiration: 2026-12-18
Also published as: WO2025262153A1

Abstract

A modular power generation island (100) for interconnection with one or more sources of thermal energy, such as a nuclear reactor, in particular a small nuclear reactor or a plurality of small modular nuclear reactors, is disclosed. The modular power generation island (100) is configured to circulate a heat transfer fluid in heat exchange relationship, by means of one or more primary heat exchangers (220), with the one or more sources of thermal energy (210) to heat the heat transfer fluid in one or more primary heat exchangers (220), wherein the modular power generation island (100) comprises a fluidic interconnection interface (11, 12), a plurality of thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22), at least one supporting frame (160) and a mechanical coupling system, the fluidic interconnection interface (11, 12) comprising at least one inlet fluidic connection (11) for the heat transfer fluid from the one or more primary heat exchangers (220) and at least one outlet fluidic connection (12) for the heat transfer fluid to the one or more primary heat exchangers (220), the plurality of thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22) being fluidically coupled with one another along a circuit according to a thermodynamic cycle configured to thermodynamically transform the heat transfer fluid to convert heat into power load and subsequently direct it to the one or more primary heat exchangers (220), the thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22) being arranged on the structural frame (160) and the mechanical coupling system being configured to structurally couple the modular power generation island (100) with a supporting structure adjacent to the source of thermal energy (200). A kit of components of the modular power generation island (100) and a method for thermodynamically transforming heat from one or more sources of thermal energy (200) are also disclosed.

Description

Modular power generation island for interconnection with a source of thermal energy

Description

TECHNICAL FIELD

[0001] The present disclosure concerns a modular power generation island for interconnection with one or more sources of thermal energy. In particular, embodiments disclosed herein specifically refer, but are not limited to, a modular power generation island for a nuclear reactor designed to circulate a heat transfer fluid in heat exchange relationship with the one or more sources of thermal energy of the nuclear reactor to heat the fluid in one or more primary heat exchangers or in one or more thermal storage systems. The fluid is processed in a closed circuit, undergoing thermodynamic transformations to convert heat into power load, in particular but not necessarily electric power. The island can be a single module or consist of interconnectable sub-modules and includes a fluidic interconnection interface with inlet and outlet connections for the heat transfer fluid, and a series of thermodynamic machines to convert heat into power load. The system may also include an electrical unit with an interface for connection to an external power source, a control unit with an interface for an external control system, and various components for managing the heat transfer fluid, such as adjustable connection devices, expanders, power generators, coolers, and compressors.

BACKGROUND ART

[0002] A combined cycle power plants is an assembly of heat engines that work in tandem from the same source of heat, converting it into mechanical energy. Mechanical energy is generally used to drive a generator to produce power. On land, when used to make electricity the most common type is called a combined cycle gas turbine (CCGT) plant. The same principle is also used for marine propulsion, where it is called a combined gas and steam (COGAS) plant. Combining two or more thermodynamic cycles improves overall efficiency, which reduces fuel costs. The principle is that after completing its cycle, also called topping cycle, in the first engine, the working fluid (the exhaust) is still hot enough that a second subsequent heat engine can extract energy from the heat in the exhaust through a second thermodynamic cycle, also called bottoming cycle. Usually, the heat passes through a heat exchanger so that the two engines can use different working fluids. Typically, when the topping cycle is a thermodynamic cycle wherein the working fluid is a gas, then the working fluid of the bottoming cycle is steam and the bottoming cycle comprises a steam generator, wherein steam is generated by heat recovered by the topping cycle and which is called Heat Recovery Steam Generator (HRSG) and one or more steam turbines. By generating power from multiple streams of work, the overall efficiency can be increased by 50-60%. Heat engines can only use part of the energy from their fuel, so in a noncombined cycle heat engine, the remaining heat (i.e., hot exhaust gas) from combustion is wasted.

[0003] Combined cycle gas turbines main advantages comprise efficiency (CCGTs are considered the most efficient fossil fuel-to-electricity converters), high flexibility, a generally low LCOE (Levelized Cost of Energy), which is largely dominated by fuel cost and varies depending on the natural gas price at a specific location. The main drawback is the high level of generated carbon emissions.

[0004] A particular kind of combined cycle power plants has a topping cycle comprising a nuclear reactor. The topping cycle, including the nuclear reactor and insulated by the environment for security reasons, is also called nuclear island, while the bottoming cycle is also called conventional island. Therefore, the conventional island is the portion of the nuclear plant dedicated to the transformation of thermal power generated from the nuclear reaction in the nuclear island into power load, generally electric power. The thermal energy is transferred from the nuclear island to the conventional island through a primary heat exchanger, where a primary fluid coming from the nuclear island is cooled, releasing heat to a secondary fluid used as thermal vector in the conventional island and allowing heat to power conversion through a turbine/ex- pander. Due to the fact that nuclear reactors operate at very high temperature (typically up to 1000°C), several types of secondary fluids can be used, such as steam, carbon dioxide and supercritical carbon dioxide, the latter herein after referred to as sCCE. The choice of the secondary fluid depends by the temperature available from the primary fluid.

[0005] Conventional island is characterized by a single inlet of secondary fluid being heated by primary fluid and a single outlet of cooled secondary fluid after expansion in a turbine/ expander and compression in a compressor/pump. Several thermodynamic cycles can be adopted for the heat to power conversion in the conventional island, depending on the nuclear reactor type, the typically used being Brayton trans or supercritical cycles for CO2 and Rankine cycles for steam. The basic CO2 trans critical cycle for heat to power conversion is the simple cycle, including a turbine, a compressor and a cooler within them, other than an exchanger for the thermal power transfer from the primary fluid to the secondary fluid.

[0006] Small Modular Reactors (SMRs) are nuclear reactors, also including the so called Advanced Modular Reactors (or fourth generation reactors), with a power output of up to 300MWe, designed for factory construction and subsequent shipment to utilities in response to demand.

[0007] In particular, different types of Small Modular Reactors are known, including Advanced Nuclear Reactors, Water-Cooled SMRs, High-Temperature Gas-Cooled SMRs (also called HTGR), Fast Neutron SMRs, Molten Salt SMRs, Microreactors. In particular, Water-Cooled SMRs are considered the most mature technology, closest to conventional large nuclear reactors. They use light or heavy water as the coolant and moderator. Examples include: Light Water Reactors (LWRs) and Heavy Water Reactors (HWRs). High-Temperature Gas-Cooled SMRs use helium gas as the coolant and graphite as the moderator, operating at high temperatures. Fast Neutron SMRs do not have a moderator and use fast neutrons to cause fission. They often use liquid metal like sodium (SFR) or lead (LFR) as the coolant. Molten Salt SMRs use molten fluoride or chloride salts as both the coolant and fuel. Microreactors are very small SMRs generating up to around 10 MWe, with different coolants like heat pipes, gas, or liquid metal.

[0008] As other type of nuclear plants, also an SMR nuclear plant is generally configured as a combined cycle power plant and is comprised of a nuclear island, constituting the topping cycle, including the nuclear reactor and insulated by the environment for security reasons, and a so-called conventional island, constituting the bottoming cycle. The choice of the secondary fluid depends by the particular type of SMR. In fact, typically, the temperature of primary fluid from the nuclear reactor of a SMR can vary in a range between 300 and 1000°C. Usually, steam is generally used for exchanging heat with a primary fluid at a temperature comprised between 350 and 550°C, while SCO2 is used when the temperature of the primary fluid is comprised between 450 and 750°C and is more efficient than steam for temperature higher than 550°C. The temperature of the sCCh can be comprised between 31 and 1000°C and the pressure can be comprised between 73 and 300 barg while the temperature of the steam can be comprised between 200 and 900 °C and the pressure can be comprised between 30 and 200 barg. On the other side, different types of SMRs have different constraints as far as the inlet temperature of the secondary fluid returning to the nuclear island after heat exchange in the conventional island. By way of example, the minimum temperature to be guaranteed is in the range of 200°C for HTGR and 330°C for LFR.

[0009] The main feature contributing to the success of SMRs is that they are compact and transportable, adding an important value to the common feature that this kind of power generation devices share with the larger nuclear reactor of no emission in the atmosphere.

[0010] However, the set up of a SMR plant poses a plurality of issues, including the complexity and security risk connected with the installation of the plant, in particular at the interface between the nuclear island and the conventional island.

[0011] Accordingly, an improved system to address the issues of complexity of installation of the systems of the current art would be beneficial and would be welcomed in the technology. More in particular, it would be desirable to provide systems adapted to more efficiently address problems entailed by the challenges of installation, commissioning, and standardization in nuclear power plants by proposing a modular power generation island that is transportable, standardized, and efficient in construction, leading to cost reductions and improved safety.

SUMMARY

[0012] In one aspect, the subject matter disclosed herein is directed to a modular power generation island for interconnection with one or more sources of thermal energy, preferably one or more nuclear reactors, in particular a small nuclear reactor or a plurality of small modular nuclear reactors, by means of one or more primary heat exchangers, the modular power generation island (100) being designed to heat a heat transfer fluid in one or more primary heat exchangers and optionally in one or more thermal storage systems configured to receive heat from the one or more primary heat exchangers, and to circulate the heat transfer fluid in a closed circuit to convert heat into power load. The island can be configured as a single module or multiple interconnectable sub-modules, featuring a fluidic interconnection interface with inlet and outlet connections for the heat transfer fluid, and a variety of thermodynamic machines, together with their auxiliaries, for transforming the heat into power load, in particular electric power. When the island is configured as a single module, then the thermodynamic machines are all arranged on a shared structural frame provided with a mechanical coupling system configured to structurally couple the modular power generation island to a supporting structure, such as a reinforced concrete slab, adjacent to the source of thermal energy. Alternatively, when the island is configured as multiple interconnectable sub-modules, each sub-module comprising part of the thermodynamic machines, then each interconnectable sub-module can be arranged on a separate structural frame, housing all the thermodynamic machines of the sub-module, and comprises fluidic and mechanical couplings with one or more of the other sub-modules and/or with the supporting structure adjacent to the source of thermal energy. The island may be used with small modular nuclear reactors (i.e. reactors designed to deliver electrical power up to 300Mwe, for a thermal source of up to 1000MW), including Advanced Nuclear Reactors, Water-Cooled SMRs, High-Temperature Gas-Cooled SMRs (also called HTGR), Fast Neutron SMRs, Molten Salt SMRs, Microreactors and can include an electrical unit with an interface for external power sources, a control unit with an interface for external control systems, and adjustable connection devices. The heat transfer fluid can be supercritical or trans-critical carbon dioxide or steam, with corresponding thermodynamic machines such as expanders, power generators, coolers, compressors, condensers, and pumps. Additional features may include an in- ventory/startup system, lube oil console, and the ability to house the island within a structure or on a fixed or floating offshore platform or on a ship or a vessel. The one or more thermal storage systems are positioned inside a common housing with the other components of the modular power generation island or in a sub-module, but can also be positioned separately. In particular, the thermal storage system can be in fluidic connection with the one or more primary heat exchangers through an intermediate thermal fluid, preferably chosen from molten salts or CO2. The one or more primary heat exchangers are generally arranged separate from the other components, which are arranged on the shared structural frame, but can also be arranged on the same structural frame, integral to the island, forming an integrated unit. [0013] In another aspect, the subject matter disclosed herein is directed to a modular power generation island for interconnection with one or more sources of thermal energy, preferably a nuclear reactor configured as a stand-alone module, which can be built within a factory to be subsequently transported to the final site, thus enabling an easy installation and commissioning but also an easy end of life decommissioning.

[0014] In another aspect, the subject matter disclosed herein is directed to a modular power generation island for interconnection with one or more sources of thermal energy, preferably a nuclear reactor configured according to a repeatable, pre-engineered and flowless assembly design, with the result of granting a high-quality standard.

[0015] In still another aspect, the modular power generation island of the present disclosure is configured as a kit of sub-modules, comprising thermodynamic machines and featuring plug-in fluidic and mechanical interconnections. The mechanical interconnections can comprise centering mechanical devices, to allow a fast connection of the sub-modules with each other and with a supporting structure adjacent to the source of heat.

[0016] In another aspect, the present disclosure also concerns a kit of components of a modular power generation island for interconnection with one or more sources of thermal energy, the kit of components being configured to circulate a heat transfer fluid in heat exchange relationship, by means of one or more primary heat exchangers, with the one or more sources of thermal energy to heat the heat transfer fluid in the one or more primary heat exchangers, wherein the kit of components comprises a fluidic interconnection interface comprising at least one inlet fluidic connection for the heat transfer fluid from the one or more primary heat exchangers and at least one outlet fluidic connection for the heat transfer fluid to the one or more primary heat exchangers, a plurality of thermodynamic machines, at least one supporting frame and a mechanical coupling system, the plurality of thermodynamic machines being configured to be fluidically coupled with one another along a circuit according to a thermodynamic cycle configured to thermodynamically transform the heat transfer fluid to convert heat into power load and subsequently direct it to the one or more primary heat exchangers, wherein the thermodynamic machines are configured to be arranged on the structural frame and wherein the mechanical coupling system is configured to structurally couple the modular power generation island with a supporting structure, such as a reinforced concrete slab, adjacent to the source of thermal energy.

[0017] In another aspect, the present disclosure concerns a method for thermodynamically transforming heat from one or more sources of thermal energy, such as a nuclear reactor, into power load according to a thermodynamic cycle, the method comprising manufacturing a plurality of thermodynamic machines and one or more respective structural frame; arranging the thermodynamic machines together on the structural frame or separately or in groups on respective separate structural frames; fluidly coupling, according to the thermodynamic cycle, the thermodynamic machines that are arranged on the same structural frame; transporting the thermodynamic machines to the site of said sources of thermal energy; mechanically coupling the structural frames of the thermodynamic machines with one another and/or with a supporting structure adjacent to the sources of thermal energy; fluidly coupling the thermodynamic machines according to the thermodynamic cycle, with one another and/or with one or more primary heat exchangers in heat exchange relationship with the sources of thermal energy.

[0018] The modular power generation island and the method according to the present disclosure require for limited on-site preparation and substantially reduced construction time.

[0019] The modular power generation island and the method for interconnection with one or more sources of thermal energy, preferably a nuclear reactor according to the present disclosure allows for de-risking, reduction and repeatability of installa- tion/commissioning activities in nuclear power plants, following the approach known as Design One, Build Many (D1BM). The main features of the modular power generation island of the present disclosure comprise transportability, the modules being produced off-site and transported to the final site, enhancing transport and standardization, reducing design costs through standardized modular manufacturing practices. The main advantages of the modular power generation island of the present disclosure comprise: construction efficiency, modularization allowing for easier construction management, reduced risks, shorter build schedules, and up to 80% of construction work to be moved off-site, leading to cost savings and improved safety; and cost reduction, since modularization and standardization not only reduce direct and indirect costs but also enable achieving economies of scale. Additionally, main quality checks can be made in the factory, reducing the risk of cost of quality during installation/commis- sioning.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] A more complete appreciation of the disclosed embodiments of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:

Fig. l illustrates a schematic of a modular power generation island for interconnection with a source of thermal energy, according to a first embodiment;

Fig.2 illustrates a schematic of a modular power generation island for interconnection with a source of thermal energy, according to a second embodiment;

Fig.3 illustrates a schematic of a modular power generation island for interconnection with a source of thermal energy, according to a third embodiment;

Fig.4 illustrates a schematic of a modular power generation island for interconnection with a source of thermal energy, according to a fourth embodiment;

Fig.5 illustrates a schematic of a modular power generation island for interconnection with a source of thermal energy, according to a fifth embodiment; and

Fig.6 illustrates a schematic of a modular power generation island for interconnection with a source of thermal energy, according to a sixth embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

[0021] According to one aspect, the present subject matter is directed to a modular power generation island for interconnection with one or more sources of thermal energy, preferably a nuclear reactor, in particular but not necessarily a small modular nuclear reactor (SMR), the modular power generation island being configured to circulate a heat transfer fluid in heat exchange relationship with one or more sources of thermal energy by means of one or more primary heat exchangers, to heat the heat transfer fluid in the one or more primary heat exchangers or, optionally, in one or more thermal storage systems configured to receive heat from the one or more thermal exchangers, the heat transfer fluid being processed in a closed circuit and undergoing thermodynamic transformations to convert heat into power load, the modular power generation island comprising a fluidic interconnection interface, a plurality of thermodynamic machines, at least one supporting frame and a mechanical coupling system, the fluidic interconnection interface comprising at least one inlet fluidic connection for the heat transfer fluid from the one or more primary heat exchangers and at least one outlet fluidic connection for the heat transfer fluid to the one or more primary heat exchangers, the plurality of thermodynamic machines being arranged along a circuit and being configured to thermodynamically transform the heat transfer fluid to convert heat into power load and subsequently direct it to the one or more primary heat exchangers through the at least one outlet fluidic connection, the thermodynamic machines being arranged on the structural frame and the mechanical coupling system being configured to structurally couple the modular power generation island with a supporting structure adjacent to the source of thermal energy.

[0022] According to one aspect, the modular power generation island is configured as a plurality of interconnectable sub-modules and the interconnectable sub-modules are arranged singularly or in one or more groups on a same structural frame and/or on a plurality of separate structural frames, the mechanical coupling system being further configured to structurally couple the interconnectable sub-modules with one another and/or with the supporting structure adjacent to the sources of thermal energy. In particular, the mechanical coupling system can comprise centering mechanical devices.

[0023] In particular, the modular power generation island can comprise an electrical and/or control unit configured to be electrically connected with an external electric power source and/or control system.

[0024] According to another aspect, the present subject matter is directed to a modular power generation island with a fluidic interconnection interface allowing interconnection with the one or more primary heat exchangers, optionally being part of an interconnectable sub-module, and/or an electrical and/or control interface allowing interconnection between the electrical and/or control unit and the external electric power source and/or control system, optionally being part of a same or different interconnectable sub-module. The modular power generation island can also be configured to be structurally coupled, eventually coupled cantilevered, to a supporting structure adjacent to the sources of thermal energy, such as a shared supporting structure with the one or more primary heat exchangers. [0025] According to one aspect, the mechanical coupling system comprises a plurality of anchoring systems, each anchoring system including: several locking devices (from four to ten, always in pairs, composed by anchor bolt and washer) and a levelling device (composed by set of stainless steel shims plate, each shim with thickness from 0,25mm to 3mm) to be installed between the bottom side of the structural frame at base level and the soleplate to be grouted in the concrete.

[0026] According to one aspect, the present subject matter is directed to a modular power generation island wherein the heat transfer fluid is supercritical carbon dioxide (sCCh) and the thermodynamic machines comprise one or more expanders configured to expand the heat transfer fluid from the one or more primary heat exchangers or from the one or more thermal storage systems, one or more power generators directly or indirectly connected to the one or more expanders and configured to convert the kinetic energy of the one or more expanders into power load, in particular electric energy, one or more coolers downstream of the one or more expanders and configured to cool the heat transfer fluid, one or more compressors downstream of the one or more coolers and upstream of the outlet fluidic connection and configured to compress the heat transfer fluid from the one or more coolers. The modular power generation island can further comprise an inventory/ start up system, including one or more sCCh pumps and/or one or more compressors and one or more sCCh heaters optionally with a fluidic interconnection interface for the connection with an external sCCh source, such as a sCCh storage system, the inventory/ startup system being part of an interconnectable sub-module. In particular, the modular power generation island of the present disclosure can comprise a motor, connected to one of the one or more compressors and configured to drive the compressor, and optionally at least one of the one or more power generators can be configured to operate also as a motor configured to drive the compressor. Alternatively, at least one of the one or more compressors is connected to at least one of the one or more expanders.

[0027] Alternatively, the one or more expanders and the one or more compressors of the modular power generation island can be part of a same interconnectable sub-module or the one or more expanders can be part of a first interconnectable sub-module and the one or more compressors can be part of a second interconnectable sub-module, the one or more power generators being part of the same interconnectable sub-module with the one or more expanders and/or one or more motors being part of the same interconnectable sub-module with the one or more compressors.

[0028] According to an alternative aspect of the present disclosure, the heat transfer fluid of the modular power generation island is trans-critical CO2 and the thermodynamic machines comprise one or more expanders downstream of the at least one inlet fluidic connection and configured to expand the heat transfer fluid from the one or more primary heat exchangers or from the one or more thermal storage systems, one or more power generators directly or indirectly connected to the one or more expanders and configured to convert the kinetic energy of the one or more expanders into power load, one or more condensers downstream of the one or more expanders and configured to cool and condense the heat transfer fluid, one or more pumps downstream of the condensers and upstream of the at least one outlet fluidic connection and configured to direct the heat transfer fluid from the condensers to the one or more primary heat exchangers or to the one or more thermal storage systems.

[0029] According to an alternative aspect of the present disclosure, the heat transfer fluid of the modular power generation island is steam and the thermodynamic machines comprise one or more expanders downstream of the at least one inlet fluidic connection and configured to expand the heat transfer fluid from the one or more primary heat exchangers or from the one or more thermal storage systems, one or more power generators directly or indirectly connected to the one or more expanders and configured to convert the kinetic energy of the one or more expanders into power load, one or more condensers downstream of the one or more expanders and configured to cool and condense the heat transfer fluid, one or more pumps downstream of the condensers and upstream of the at least one outlet fluidic connection and configured to direct the heat transfer fluid from the condensers to the one or more primary heat exchangers or to the one or more thermal storage systems through the at least one outlet fluidic connection. In particular, the modular power generation island according to this aspect can comprise one or more pre-heaters, downstream of the condensers, one or more de-aerators, downstream of the pre-heaters and configured to remove gas from the condensate, and a vacuum group.

[0030] In one aspect, the present subject matter is directed to a modular power generation island arranged on a fixed or floating offshore platform or on a ship or a vessel. In such cases, the power load produced by the modular power generation island can be used for marine propulsion. Alternatively, the single module or the plurality of interconnectable sub-modules of the modular power generation island can be road transportable modules.

[0031] According to one aspect of the present disclosure, the modular power generation island comprises fluidic interconnection interfaces configured to connect the interconnectable sub-modules to one another or to the one or more primary heat exchangers or to the one or more thermal storage systems, and mechanical coupling interfaces configured to structurally couple the interconnectable sub-modules to one another or to the one or more primary heat exchangers or to the supporting structure adjacent to the one or more thermal storage system. In particular, the one or more primary heat exchangers can be integral with the modular power generation island, to form an integrated modular power generation island.

[0032] According to one aspect of the present disclosure, the structure of the modular power generation island is made by fully welded steel elements sized and braced to ensure structural adequacy during both operating and pre-service conditions, which include land and/or sea transportation, load-out and/or load-in and/or jacking up and/or jacking-down. Main deck’s primary steel can be made by fabricated plate girders, typically for shapes exceeding 600mm in height. Both primary and secondary steelwork are made from high strength material, whereas tertiary steelwork items can be fabricated from mild steel. The foundation (cement selection or topside module support frame in case of platform and anchoring system sizing) is sized to obtain the best static and dynamic behavior of the module (design considering permanent loads such as dead load, live and/or variable loads such as inventory load and monorail and/or lifting lugs load, thermal operating load, piping operating load, road and/or sea transport load, wind load, blast load, fire load, snow load, ice load, temperature load, earthquake load). Anchoring system is selected according to the applicable loads combination from the above list and it includes several anchor points (typical 50-100), each of them located at the bottom of structural vertical beams/columns. Each anchoring system includes: several locking devices (from four to ten, always in pairs, composed by anchor bolt and washer) and a levelling device (composed by set of stainless steel shims plate, each shim with thickness from 0,25mm to 3mm) to be installed between the bottom side of the structural frame at base level and the soleplate to be grouted in the concrete or welded on the topside module support frame in case of platform. [0033] According to another aspect of the present disclosure, it is disclosed a kit of components of a modular power generation island for interconnection with one or more sources of thermal energy, the kit of components being configured to circulate a heat transfer fluid in heat exchange relationship, by means of one or more primary heat exchangers, with the one or more sources of thermal energy to heat the heat transfer fluid in the one or more primary heat exchangers, wherein the kit of components comprises a fluidic interconnection interface comprising at least one inlet fluidic connection for the heat transfer fluid from the one or more primary heat exchangers and at least one outlet fluidic connection for the heat transfer fluid to the one or more primary heat exchangers, a plurality of thermodynamic machines, at least one supporting frame and a mechanical coupling system, the plurality of thermodynamic machines being configured to be fluidically coupled with one another along a circuit according to a thermodynamic cycle configured to thermodynamically transform the heat transfer fluid to convert heat into power load and subsequently direct it to the one or more primary heat exchangers, wherein the thermodynamic machines are configured to be arranged on the structural frame and wherein the mechanical coupling system is configured to structurally couple the modular power generation island with a supporting structure, such as a reinforced concrete slab, adjacent to the source of thermal energy.

[0034] In another aspect, the present disclosure concerns a method for thermodynamically transforming heat from one or more sources of thermal energy, such as a nuclear reactor, in particular a small nuclear reactor or a plurality of small modular nuclear reactors, into power load according to a thermodynamic cycle, the method comprising:

- manufacturing a plurality of thermodynamic machines;

- manufacturing one or more structural frames;

- arranging the thermodynamic machines together on the structural frame or separately or in groups on the plurality of structural frames;

- fluidly coupling, according to the thermodynamic cycle, the the thermodynamic machines that are arranged on the same structural frame;

- transporting the thermodynamic machines to the site of said sources of thermal energy;

- mechanically coupling the thermodynamic machines with one another and/or with a supporting structure adjacent to the sources of thermal energy; - fluidly coupling the thermodynamic machines according to the thermodynamic cycle, with one another and/or with one or more primary heat exchangers in heat exchange relationship with the sources of thermal energy.

[0035] Reference now will be made in detail to embodiments of the disclosure, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the disclosure, not limitation of the disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present disclosure without departing from the scope or spirit of the disclosure. Reference throughout the specification to “one embodiment” or “an embodiment” or “some embodiments” means that the particular feature, structure or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrase “in one embodiment” or “in an embodiment” or “in some embodiments” in various places throughout the specification is not necessarily referring to the same embodiment s). Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

[0036] When introducing elements of various embodiments the articles “a”, “an”, “the”, and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including”, and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0037] In the context of the present disclosure, the term thermodynamic machine is used to refer also to auxiliary machines operating with the same thermodynamic cycle circuit of properly intended thermodynamic machines, while the term plug connection device, referred to the fluidic connections, is intended to refer to means of connection pre-arranged to be connected, allowing an easier connection and disconnection, minimizing construction time, in particular without the need of welding on site.

[0038] Referring now to the drawings, Fig.l shows a schematic of an exemplary modular power generation island 100 for interconnection with a source of thermal energy 200, in particular a nuclear reactor 200. The modular power generation island 100 is designed to circulate a heat transfer fluid in heat exchange relationship with the source of thermal energy to heat the fluid in one or more primary heat exchangers 220. The fluid is then processed in a plurality of thermodynamic machines 13, 14, 15, 16, 17, 18, 19, 20, 21, 22 arranged on a supporting frame 160 along a closed circuit, undergoing thermodynamic transformations to convert heat into power load, in particular but not necessarily into electric power. The modular power generation island 100 can be a single module or consist of interconnectable sub-modules and includes a fluidic interconnection interface with inlet 11 and outlet 12 connections for the heat transfer fluid, and a series of thermodynamic machines to convert heat into power load. The modular power generation island 100 comprises a mechanical coupling system configured to structurally couple the modular power generation island 100 with a supporting structure adjacent to the nuclear reactor 200.

[0039] In particular, the modular power generation island 100 of Fig. 1 is configured to use supercritical carbon dioxide (sCCh) as heat transfer fluid, to exchange heat with a thermal fluid of a nuclear reactor 200 through a primary heat exchanger 220. An inlet fluidic connection 11 connects the primary heat exchanger 220 with the modular power generation island 100 and is configured to direct the heat transfer fluid to an expander 19, which is connected to a power generator 20, configured to convert the kinetic energy of the expander 19 into power load. A cooler 21 is connected downstream of the expander 19, to cool the heat transfer fluid, which is subsequently directed to a compressor 22 upstream of an outlet fluidic connection 12 and configured to compress the heat transfer fluid from the cooler before it is directed again to the primary heat exchanger 220 to exchange heat with the thermal fluid 210 from the nuclear reactor 200. The compressor 22 is connected to a motor 28, which is configured to drive the compressor 22. The modular power generation island 100 further comprises an inven- tory/start up system 25, with one or more sCCh pumps and/or one or more compressors and one or more sCCh heaters. A sCCh storage system 27 is connected to the inven- tory/startup system 25 through a fluidic interconnection interface 26. One or more regenerators 31 are also present for heat recovery in regenerative cycles to increase efficiency. Finally, the modular power generation island 100 of Fig. 1 comprises an electrical and/or control unit 50 and a respective electrical and/or control interface 51, configured to be electrically connected with an external electric power source and/or control system 52.

[0040] In general, a modular power generation island 100 of the type shown with reference to Fig. 1 comprises one or multiple turbines 19 with a power generator 20, one or more compressors 22 with related auxiliaries, one or more electric machines having function of motor and generator or separated motor 29 and generator. Any combination of the components above is also possible. The modular power generation island 100 can also comprise one or more coolers 21 upstream the one or more compressors 22, one or more regenerators 31, an inventory/ start-up system 25 and electrical & control components 50. The inventory/ startup system 25 manages the sCCh working fluid, ensuring the appropriate amount is available for the system's operation and providing the necessary startup capabilities. Main components are CO2 pumps and/or compressors, and CO2 heaters. The inventory/ startup system 25 is included in the modular power generation island 100 and is connected to a CO2 storage system 27.

[0041] Thus, the modular power generation island 100 constitutes a single or multi module assembly for interconnection with a nuclear reactor 200, with a single fluidic inlet and outlet interface between the modular power generation island 100 and the primary heat exchanger 220 connected to the nuclear reactor 200.

[0042] The modular power generation island 100 allows to configure adjustable fluidic connections with the primary heat exchanger 220, in particular through an intermediate connection increasing flexibility of connection location. The connection between the primary heat exchanger 220 and the modular power generation island 100 is realised through piping routing, heated fluid going from the primary heat exchanger 220 to the modular power generation island 100 and cooled fluid going from the modular power generation island 100 and the primary heat exchanger 220. Piping pressure level depends on the fluid selected and the related thermodynamic cycle, in the embodiment of Fig. 1 the fluid being CO2 and the thermodynamic cycle being a Brayton cycle. The modular power generation island 100 is connectable to the primary heat exchanger 220 through single flanged connection for fluid inlet and single flanged connection for fluid outlet: the same can be located on the module edge on either common or adjacent sides or on the top to allow plug-in customer piping assembly. In case the modular power generation island 100 is divided into two or more sub-modules, such connections can be in the same sub-module (typically if all turbomachinery is in the same sub-module) or different sub-modules (typically when fluid inlet in the conventional island is in a sub-module including expansion trains and fluid outlet from the modular power generation island 100 is in a sub-module including the compression trains. The mechanical couplings of the modular power generation island 100 allow to configure adjustable mechanical connections with a supporting structure adjacent to the nuclear reactor 200, which can be a foundation (cement selection or topside module support frame in case of platform and anchoring system sizing) properly sized to obtain the best static and dynamic behavior of the module (design considering permanent loads such as dead load, live/variable loads such as inventory load and monorail/lifting lugs load, thermal operating load, piping operating load, road/sea transport load, wind load, blast load, fire load, snow load, ice load, temperature load, earthquake load).

[0043] The mechanical coupling system comprises a plurality of anchoring systems. Each anchoring system includes several locking devices (from four to ten, always in pairs, composed by anchor bolt and washer) and a levelling device (composed by set of stainless steel shims plate, each shim with thickness from 0,25mm to 3mm) to be installed between the bottom side of the structural frame at base level and the soleplate to be grouted in the concrete.

[0044] In some cases, the concept of modularization can be complemented with the concept of modularity for modular power generation island 100: multiple smaller capacity modular power generation island 100 can be selected to deploy the entire plant power capacity, each modular power generation island 100 being constructed in a single module or multiple sub-modules. Inlet and outlet connections are characterized as specified above if each smaller capacity modular power generation island 100 (or plurality of sub-modules) is coupled with a dedicated primary heat exchanger 220. In case a single primary heat exchanger 220 is designed to feed multiple smaller capacity modular power generation island 100, each smaller capacity modular power generation island 100 is provided with inlet and outlet connections as above described, for only a portion of the entire fluid flow heated by the single primary heat exchanger.

[0045] In one aspect, the electrical and control system 50 is completely wired in the modular power generation island 100. A common Local Electrical Room (LER) can be included in the modular power generation island 100 to elaborate and distribute the plant electric power supply. Additionally, a common Control Room (CR) can be included in the modular power generation island 100 to elaborate and distribute the In and Out (EO) signals to be exchanged with the plant digital control system and to exploit direct control of the regulating devices. As a result, the wired connections be- tween the plant electric substation and the plant digital control system room are respectively reduced, thus allowing optimized and flexible interconnecting cables selection between the modular power generation island 100 and the plant based on the plant cable list.

[0046] In case the modular power generation island 100 is divided in two or more sub-modules, LER and/or CR can be in the same sub-module or in different sub-modules. In all cases LER and/or CR are foreseen on the module (or sub-module) lateral position, in the same or different edge(s), to allow plug-in wiring connection for plant cables. Electric and/or control cables between adjacent sub-modules are supplied completely fabricated and the sub-modules assembly at site may be facilitated though the use of detachable electric connectors for the electric and/or control cables.

[0047] Several embodiments of possible modular power generation island 100 will be described below with reference to the following Figs. 2, 3, 4, 5 and 6.

[0048] With continuing reference to Fig. 1, a further embodiment of a modular power generation island 100 is shown in Fig.2. The same reference numbers designate the same or corresponding parts, elements or components already illustrated in Fig. 1 and described above, and which will not be described again. The modular power generation island 100 of Fig.2 also uses sCCh as thermal fluid and differs from the modular power generation island 100 of Fig.1 mainly in that the expander 19 and the compressor 22 are coupled through a gear 30 and are connected to a power generator 29’ that is configured to operate also as a motor, to drive the compressor 22. The remaining components of the modular power generation island 100 of Fig.2 are the same already described with reference to Fig.1.

[0049] With continuing reference to Figs. 1 and 2, a further embodiment of a modular power generation island 100 is shown in Fig.3. The same reference numbers designate the same or corresponding parts, elements or components already illustrated in Figs. 1 and 2 and described above, and which will not be described again. The modular power generation island 100 of Fig.3 differs from the modular power generation island 100 of Fig.2 mainly in that it is divided in three sub-modules 140a, 140b and 150 arranged on respective structural frames 160’, 160”, 160’”. The expander 19 and all its auxiliaries, as well as the power generator 20, are part of a first sub-module 140a, while the compressor 22 and all its auxiliaries, as well as the motor 29 are part of a second submodule 140b, and the cooler 21 and the inventory/startup system 25 are part of a third sub-module 150. The interconnection between the modular power generation island 100 and the primary heat exchanger 220 is distributed through different sub-modules, the inlet fluidic connection 11 being connected to the first sub-module 140a and the outlet fluidic connection 12 being connected to the second sub-module 140b. In particular, the sub-module level could depend by power size (between 10 MW to 1000 MW).

[0050] The single module or multiple sub-modules can cover the full power range of the modular power generation island 100 or smaller capacity when the concept of modularity is adopted. As an example, different configurations of the modular power generation island 100 can be provided for nuclear reactors with thermal capacity of 20 MWe, 40MWe, 80MWe, or lOOMwe.

[0051] In particular, when a configuration of multiple sub-modules is adopted, each sub-module can include one or more of the components of the modular power generation island 100 as described above, optimizing layout through the selection of functional unit. The dimension of each sub-module can be optimized to include the functional unit selected and respect transportation constraints (in particular road transportation constraints). As an example, one sub-module can be dedicated to single or multiple compression trains and related motors or can be dedicated to single or multiple turbines and related power generators or it can be dedicated to common compression and expansion train and related electric machine acting both as motor and generator.

[0052] Additionally, when a configuration of multiple sub-modules is adopted, the sub-modules can be connected by means of a structural module frame 160, such as a frame formed through beams. Some sub-modules can be cantilevered.

[0053] A single input/output fluidic interface can be provided between the modular power generation island 100 and the primary heat exchanger 220 connected to the nuclear reactor 200. The same input/output fluidic connection interface can be included in the modular power generation island 100, both when configured as a single module and as multiple sub-modules. By way of example, the inlet fluidic connection 11 can be located in the single module 100 or in the sub-module 140a including the expander [0054] All fluid connections inside the modular power generation island 100 and between the sub-modules are fabricated in factory. Fluidic connections among sub-modules are fabricated in factory through prefabricated piping spools, minimizing erection effort.

[0055] The structure of the modular power generation island 100 is configured to allow assembly on concrete or fixed/floating platform for on shore or off shore applications, in platform structure and/or cantilevered. Sub-modules can be prefabricated in factory to allow a plug and play assembly in field as a single structure, minimizing erection costs and time. This is realized through mechanical junctions on the structural elements of each sub-module fabricated in factory and dismantled for transportation, located on external beam of each sub-module frame.

[0056] Optionally, a single electrical/control interface for the modular power generation island 100, with plant DCS/electric substations through dedicated control/electric room can be located inside the single module or one of the sub-modules. All the instrum entation/electric connections inside the single module and sub-modules are fabricated in factory and electric/power connections between sub-modules are minimized through adoption of proper substations.

[0057] Single module or multiple sub-modules can include movable skids to simplify turbomachinery maintenance. According to some embodiments, the movable skids are slidably movable on rails or the like.

[0058] In case the modular power generation island 100 is divided in two or more sub-modules, piping interconnections between adjacent sub-modules can be completely fabricated in factory, by the use or either flanged junctions at modules edge or prefabricated piping spools between adjacent sub-modules to be disassembled for transport, being those connections located either on top and/or on one side and/or on the bottom of the sub-modules, with the aim to avoid piping welding at site.

[0059] Plug-in sub-modules assembly at site is allowed by the design, manufacturing and assembly of centering mechanical devices on the structural elements edge of each frame of adjacent sub-modules. Such centering mechanical devices can be provided for vertical and/or horizontal assembly of adjacent sub-modules, to allow configuration assembly of two or more elevation levels structure and/or two or more sub-module structures on the same elevation. Number and size of centering devices are tailored for the specific sub-module dimension and weight, being always provided with regulating parts that allow adjusting and centering vertically and/or horizontally during field assembly to enable prefabricated mechanical and electrical connections proper assembly and assure minimization of installation time by adoption of plug-in concept.

[0060] With continuing reference to Figs. 1, 2 and 3, Fig. 4 illustrates a further embodiment of a modular power generation island 100. The same reference numbers used in Figs. 1, 2 and 3 are used in Fig. 4 to designate the same or corresponding parts, components or elements, which will not be described again. The embodiment of Fig. 4 differs from the embodiment of Fig. 3 mainly in that the sub-modules are different, the sub-modules of the system of Fig. 4 including a first interconnectable sub-module 140, comprising the expander 19 and the compressor 22, together with their auxiliaries, a power generator 20 and a motor 29. The first interconnectable sub-module 140 is arranged on a first structural frame 160”. A second interconnectable sub-module 150 is also present and is arranged on a second structural frame 160”’. The two frames 160”, 160”’ are arranged on a shared structural frame 160’. The shared structural frame 160’ is further housing the thermal exchanger 220. Additionally, the embodiment of Fig. 4 also shows a thermal storage system 40 receiving heat from the thermal exchanger 220 through an intermediate thermal fluid, such as a molten salt or CO2, circulating between the thermal storage system 40 and the thermal exchanger 220 through the inlet fluidic connection 11 and the outlet fluidic connection 12. The heat transfer fluid of the modular power generation island 100 is heated inside the thermal storage system 40 and is directed to the thermodynamic machines through the line 41. The cold heat transfer fluid is then directed from the thermodynamic machines to the thermal storage system 40 through the line 42.

[0061] Referring to Fig.5, with continuing reference to Figs. 1, 2, 3 and 4, a further embodiment of the modular power generation island 100 is disclosed. The modular power generation island 100 of Fig. 5 differs from the modular power generation island 100 of Figs.1-4 mainly in that it is configured to work with steam as the thermal fluid, according to a Rankine cycle. In particular, the Fig. 5 shows a modular power generation island 100, to exchange heat with thermal fluid of a source of thermal energy through a primary heat exchanger 220. Similarly to the embodiment of Fig.4, also the embodiment according to Fig.5 comprises a structural frame 160 housing the primary heat exchanger 220. An inlet fluidic connection 11’ connects the primary heat exchanger 220 with the modular power generation island 100 and is configured to direct the heat transfer fluid to an expander 13, namely a steam turbine 13, which is connected to a power generator 14, configured to convert the kinetic energy of the expanders 13 into power load. A condenser 15 is connected downstream of the expander 13, to cool and condensate the heat transfer fluid, which is subsequently directed to a condensate pump 16 and subsequently, in sequence, to one or more pre-heaters 17, one or more de-aerators 18, to remove gas from the condensate, and to the outlet fluidic connection 12’ through which the heat transfer fluid is directed again to the primary heat exchanger 220 to exchange heat with the thermal fluid of the source of thermal energy. The modular power generation island 100 further comprises a vacuum group 23 and an electrical and/or control unit 50 with a respective electrical and/or control interface 51, configured to be electrically connected with an external electric power source and/or control system 52.

[0062] The Rankine cycle thermodynamic cycle with steam is generally characterized by a fixed minimum temperature to be guaranteed at the inlet temperature of the secondary fluid returning to the nuclear island after heat exchange in the conventional island, such fixed minimum temperature depending on the source of thermal energy. By way of example, if the source of thermal energy is a nuclear reactor, the fixed minimum temperature to be guaranteed is in the range of 200°C for HTGR or 330°C for LFR. This implies the presence of some heat-exchangers to pre-heat/regenerate the steam that is fed by some bleedings from the steam turbine.

[0063] The steam turbine generator train can be geared or directly connected to the steam turbine 13, axially or radially. Generally, a gearbox is used up to 50MW of power; above that threshold the turbine is directly connected to a two-pole generator.

[0064] The condensate pumps 16 can be driven by the steam turbine 13 and/or by an electrical motor, operating as main and stand-by driving devices. The vacuum group 23 comprises inter-condenser and/or after condenser and ejectors or vacuum ring pumps. Heat-exchangers, namely regenerative heat exchangers (regenerators) and/or pre-heater are present to heat the bleedings and/or the extractions of steam. A water treatment package, out of the modular power generation island 100, can also be present.

[0065] The modular power generation island can be supplied in a single or multi module assembly, with a single input/output interface between the assembly and the primary heat exchanger 220 connected to the source of thermal energy.

[0066] With continuing reference to Figs. 1, 2, 3, 4 and 5, in Fig.6 a further embodiment of a modular power generation island 100 is illustrated. The modular power generation island 100 of Fig. 6 is substantially identical to the modular power generation island 100 of Fig.5, except that it is divided in three sub-modules 110, 120 and 130, all arranged on a shared structural frame 160. The expander 13 and all its auxiliaries, as well as the power generator 14, are part of a first sub-module 110, while the condenser 15, the condensate pump 16 and the pre-heaters 17 are part of a second submodule 120 and the de-aerators 18 are part of a third sub-module 130.

[0067] The various arrangements illustrated in Figs. 1 to 6 can be variously combined to one another.

[0068] While the invention has been described in terms of various specific embodiments, it will be apparent to those of ordinary skill in the art that many modifications, changes, and omissions are possible without departing form the spirt and scope of the claims. In addition, unless specified otherwise herein, the order or sequence of any process or method steps may be varied or re-sequenced according to alternative embodiments.

Claims

Modular power generation island for interconnection with a source of thermal energy CLAIMS

1. A modular power generation island (100) for interconnection with one or more sources of thermal energy (200), such as a nuclear reactor, in particular a small nuclear reactor or a plurality of small modular nuclear reactors, the modular power generation island (100) being configured to circulate a heat transfer fluid in heat exchange relationship, by means of one or more primary heat exchangers (220), with the one or more sources of thermal energy (200) to heat the heat transfer fluid in the one or more primary heat exchangers (220), wherein the modular power generation island (100) comprises a fluidic interconnection interface (11, 12), a plurality of thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22), at least one supporting frame (160) and a mechanical coupling system, the fluidic interconnection interface (11, 12) comprising at least one inlet fluidic connection (11) for the heat transfer fluid from the one or more primary heat exchangers (220) and at least one outlet fluidic connection (12) for the heat transfer fluid to the one or more primary heat exchangers (220), the plurality of thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22) being fluidically coupled with one another along a circuit according to a thermodynamic cycle configured to thermodynamically transform the heat transfer fluid to convert heat into power load and subsequently direct it to the one or more primary heat exchangers (220), the thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22) being arranged on the structural frame (160) and the mechanical coupling system being configured to structurally couple the modular power generation island (100) with a supporting structure adjacent to the source of thermal energy (200).

2. The modular power generation island (100) of claim 1, further comprising one or more thermal storage systems (40) configured to receive heat from the one or more primary heat exchangers (220).

3. The modular power generation island (100) of claim 1 or 2, wherein the modular power generation island (100) is configured as a plurality of interconnectable sub-modules (110, 120, 130, 140, 140a, 140b, 150) and wherein the interconnectable sub-modules (110, 120, 130, 140, 140a, 140b, 150) are arranged singularly or in one or more groups on a same structural frame (160) and/or on a plurality of separate structural frames (160’, 160”, 160’”), the mechanical coupling system being further configured to structurally couple the interconnectable sub-modules (110, 120, 130, 140, 140a, 140b, 150) with one another and/or with the supporting structure adjacent to the sources of thermal energy.

4. The modular power generation island (100) of claim 3, wherein the mechanical coupling system comprises centering mechanical devices.

5. The modular power generation island (100) of one or more of the preceding claims, further comprising an electrical and/or control unit (50) and a respective electrical and/or control interface (51) configured to be electrically connected with an external electric power source (52) and/or control system.

6. The modular power generation island (100) of claim 5, wherein the electrical and/or control unit (50) and the electrical and/or control interface (51) are part of an interconnectable sub-module.

7. The modular power generation island (100) of one or more of the preceding claims, wherein the primary heat exchangers (220) and the plurality of thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22) are fluidically coupled by means of plug connection devices.

8. The modular power generation island (100) of one or more of the preceding claims, wherein the mechanical coupling system comprises a plurality of anchoring systems, each anchoring system including at least two couples of locking devices.

9. The modular power generation island (100) of the preceding claim, wherein each locking device is composed of an anchor bolt and a washer.

10. The modular power generation island (100) of claim 8 or 9, wherein the mechanical coupling system further comprises a levelling device.

11. The modular power generation island (100) of one or more of the preceding claims, wherein the structural frame (160) comprises a seat for the one or more primary heat exchangers (220).

12. The modular power generation island (100) of one or more of the preceding claims, the one or more primary heat exchangers (220) are arranged on the structural frame (160).

13. The modular power generation island (100) of one or more of the preceding claims, further comprising an intermediate fluidic connection module arranged between the one or more primary heat exchangers (220) and the plurality of thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22).

14. The modular power generation island (100) of one or more of claims 1-13, wherein the heat transfer fluid is supercritical or trans-critical carbon dioxide (sCO₂).

15. The modular power generation island (100) of claim 14, wherein when the heat transfer fluid is supercritical carbon dioxide (sCO₂) the thermodynamic machines (19, 20, 21, 22) comprise: one or more expanders (19) downstream of the at least one inlet fluidic connection (11) and configured to expand the heat transfer fluid from the one or more primary heat exchangers (220) or from the one or more thermal storage systems (40); one or more power generators (20) directly or indirectly connected to the one or more expanders (19) and configured to convert the kinetic energy of the one or more expanders (19) into power load; one or more coolers (21) downstream of the one or more expanders (19) and configured to cool the heat transfer fluid; and one or more compressors (22) downstream of the one or more coolers (21) and upstream of the outlet fluidic connection (12) and configured to compress the heat transfer fluid from the one or more coolers (21).

16. The modular power generation island (100) of claim 15, further comprising an inventory/ start up system (25).

17. The modular power generation island (100) of claim 16, wherein the inventory/startup system (25) comprises one or more sCO₂ pumps and/or one or more compressors and/or one or more sCO₂ heaters.

18. The modular power generation island (100) of claim 16 or 17, wherein the inventory/startup system (25) comprises a fluidic interconnection interface (26) for the connection with an external sCO₂ source, such as a sCO₂ storage system

19. The modular power generation island (100) of one or more of claims 16-18, wherein the inventory/startup system (25) is part of an interconnectable submodule.

20. The modular power generation island (100) of one or more of claims 15-19, wherein at least one of the one or more compressors (22) is connected to a motor (28), which is configured to drive the at least one compressor (22).

21. The modular power generation island (100) of one or more of claims 15-20, wherein at least one of the one or more compressors (22) is connected to at least one of the one or more expanders (19).

22. The modular power generation island (100) of one or more of claims 15-21, wherein at least one of the one or more power generators (29’) is configured to operate also as a motor, which is configured to drive at least one of the one or more compressors (22).

23. The modular power generation island (100) of one or more of claims 15-22, wherein at least one of the one or more expanders (19) and at least one of the one or more compressors (22) are part of a same interconnectable sub-module (140).

24. The modular power generation island (100) of one or more of claims 15-23, wherein the one or more expanders (19) are part of a first interconnectable submodule (140a) and the one or more compressors (22) are part of a second interconnectable sub-module (140b).

25. The modular power generation island (100) of claim 23 or 24, wherein the one or more power generators (20, 29) are part of the same interconnectable sub-module (140, 140a) with the one or more expanders (19) and/or one or more motors (28) are part of the same interconnectable sub-module (140, 140b) with the one or more compressors (22).

26. The modular power generation island (100) of one or more of claims 15-25, wherein the one or more coolers (21) and the inventory/startup system (25) are part of a same interconnectable sub-module (150).

-27-

27. The modular power generation island (100) of one or more of claims 15-26, wherein the temperature of the one or more sources of thermal energy (210) is comprised in a range between approximately 200 and 1000°C, preferably between approximately 450-650 °C.

28. The modular power generation island (100) of one or more of claims 15-27, wherein the temperature of the sCCh is comprised between 31 and 1000°C and the pressure is comprised between 73 and 300 barg.

29. The modular power generation island (100) of one or more of claims 1-13, wherein the heat transfer fluid is steam.

30. The modular power generation island (100) of claim 29, wherein the thermodynamic machines (13, 14, 15, 16, 17, 18) comprise one or more expanders (13) downstream of the at least one inlet fluidic connection (11) and configured to expand the heat transfer fluid from the one or more primary heat exchangers (220) or from the one or more thermal storage systems (40), one or more power generators (14) directly or indirectly connected to the one or more expanders (13) and configured to convert the kinetic energy of the one or more expanders (13) into power load, one or more condensers (15) downstream of the one or more expanders (13) and configured to cool and condense the heat transfer fluid, one or more pumps (16) downstream of the condensers (15) and upstream of the at least one outlet fluidic connection (12) and configured to direct the heat transfer fluid from the condensers (15) to the one or more primary heat exchangers (220) or to the one or more thermal storage systems (40).

31. The modular power generation island (100) of claim 30, further comprising one or more pre-heaters (17), downstream of the condensers (15).

32. The modular power generation island (100) of claim 31, further comprising one or more de-aerators (18), downstream of the pre-heaters (17) and configured to remove gas from the condensate.

33. The modular power generation island (100) of one or more of claims 30-32, further comprising a vacuum group (23).

34. The modular power generation island (100) of one or more of claims 30-33, wherein the modular power generation island (100) is configured as a plurality of interconnectable sub-modules (110, 120, 130) comprising a first module (110) configured to house the expander (13) and the one or more power generators (14).

35. The modular power generation island (100) of one or more of claims 30-34, wherein the modular power generation island (100) is configured as a plurality of interconnectable sub-modules (110, 120, 130) comprising a second module (120) configured to house: the condensers (15) and the one or more expanders (13), configured to cool and condense the heat transfer fluid; one or more pumps (16) downstream of the condensers (15) and upstream of the outlet fluidic connection (12) and configured to direct the heat transfer fluid from the condensers (15) to the one or more primary heat exchangers (220) or to the one or more thermal storage systems (40).

36. The modular power generation island (100) of claim 35, wherein the second module (120) is configured to additionally house one or more pre-heaters (17).

37. The modular power generation island (100) of one or more of claims 32-36, wherein the modular power generation island (100) is configured as a plurality of interconnectable sub-modules (110, 120, 130) comprising a third module (120) configured to house the de-aerator (18).

38. The modular power generation island (100) of one or more of claims 32-37, wherein the temperature of the one or more sources of thermal energy (210) is comprised in a range between approximately 200 and 900°C, preferably between approximately 350 and 450°C.

39. The modular power generation island (100) of one or more of claims 32-38, wherein the temperature of the steam is comprised between 200 and 900 °C and the pressure is comprised between 30 and 200 barg.

40. The modular power generation island (100) of one or more of the preceding claims, wherein the one or more thermal storage systems (40) are positioned inside the common housing (160) or inside an interconnectable sub-module.

41. The modular power generation island (100) of claim 40, wherein the thermal storage system (40) is in fluidic connection with the one or more primary heat exchanger (220) through an intermediate thermal fluid, preferably chosen from molten salts or CO2.

42. The modular power generation island (100) of one or more of the preceding claims, wherein the mechanical coupling system of the modular power generation island (100) comprises means configured to arrange the modular power generation island (100) cantilevered with respect to the one or more main heat exchangers (220).

43. The modular power generation island (100) of one or more of the preceding claims, wherein the modular power generation island (100) is arranged on an offshore platform.

44. The modular power generation island (100) of one or more of the preceding claims, wherein the offshore platform is a fixed offshore platform or a floating offshore platform.

45. The modular power generation island (100) of one or more of the preceding claims, wherein the modular power generation island (100) is arranged on a vessel or ship.

46. The modular power generation island (100) of claim 45 wherein the power load is used for powering different kinds of services on the vessel or ship, including marine propulsion.

47. The modular power generation island (100) of one or more of the preceding claims, wherein the single module or the plurality of interconnectable submodules (110, 120, 130, 140, 140a, 140b, 150) are road transportable modules.

48. The modular power generation island (100) of one or more of the preceding claims, further comprising fluidic interconnection interfaces configured to connect the interconnectable sub-modules (110, 120, 130, 140, 140a, 140b, 150) to one another and/or to the one or more primary heat exchangers (220) and/or to the one or more thermal storage systems (40).

49. The modular power generation island (100) of one or more of the preceding claims, further comprising mechanical coupling interfaces configured to structurally couple the interconnectable sub-modules (110, 120, 130, 140, 140a, 140b, 150) to one another and/or to the one or more primary heat exchangers (220) and/or to the one or more thermal storage systems (40).

50. The modular power generation island (100) of one or more of the preceding claims, wherein the one or more primary heat exchangers (220) are integral with the modular power generation island (100) to form an integrated modular power generation island.

51. A kit of components of a modular power generation island (100) for interconnection with one or more sources of thermal energy (200), such as a nuclear reactor, in particular a small nuclear reactor or a plurality of small modular nuclear reactors, the kit of components being configured to circulate a heat transfer fluid in heat exchange relationship, by means of one or more primary heat exchangers (220), with the one or more sources of thermal energy (200) to heat the heat transfer fluid in the one or more primary heat exchangers (220), wherein the kit of components comprises a fluidic interconnection interface (11, 12) comprising at least one inlet fluidic connection (11) for the heat transfer fluid from the one or more primary heat exchangers (220) and at least one outlet fluidic connection (12) for the heat transfer fluid to the one or more primary heat exchangers (220), a plurality of thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22), at least one supporting frame (160) and a mechanical coupling system, the plurality of thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22) being configured to be fluidically coupled with one another along a circuit according to a thermodynamic cycle configured to thermodynamically transform the heat transfer fluid to convert heat into power load and subsequently direct it to the one or more primary heat exchangers (220), wherein the thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22) are configured to be arranged on the structural frame (160) and wherein the mechanical coupling system is configured to structurally couple the modular power generation island (100) with a supporting structure, adjacent to the source of thermal energy (200).

52. The kit of components of claim 51, further comprising one or more thermal storage systems (40) configured to receive heat from the one or more primary heat exchangers (220).

53. The kit of components of claim 51 or 52, wherein the components are configured to be arranged as a plurality of interconnectable sub-modules (110, 120, 130, 140, 140a, 140b, 150) and wherein the interconnectable sub-modules (110, 120, 130, 140, 140a, 140b, 150) are arranged singularly or in one or more groups on a same structural frame (160) and/or on a plurality of separate structural frames (160’, 160”, 160’”), the mechanical coupling system being further configured to structurally couple the interconnectable sub-modules (110, 120, 130, 140, 140a, 140b, 150) with one another and/or with a supporting structure.

54. The kit of components of claim 53, wherein the mechanical coupling system comprises centering mechanical devices.

55. The kit of components of claim 53 or 54, wherein the structural frame (160) comprises a seat for the one or more primary heat exchangers (220).

56. A method for thermodynamically transforming heat from one or more sources of thermal energy (200), such as a nuclear reactor, in particular a small nuclear reactor or a plurality of small modular nuclear reactors, into power load according to a thermodynamic cycle, the method comprising:

- manufacturing a plurality of thermodynamic machines (13, 14, 15, 16, 17, 18,

19, 20, 21, 22);

- manufacturing one or more structural frames (160, 160’, 160”, 160’”);

- arranging the thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22) together on the structural frame (160) or separately or in groups on the plurality of structural frames (160’, 160”, 160’”);

- fluidly coupling, according to the thermodynamic cycle, the thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22) that are arranged on the same structural frame (160, 160’, 160”, 160’”) to form one or more separate modules (100, 140, 140a, 140b, 150);

- transporting the one or more separate modules (100, 140, 140a, 140b, 150) to the site of said sources of thermal energy (200);

- mechanically coupling the thermodynamic machines (13, 14, 15, 16, 17, 18, 19,

20, 21, 22) with one another and/or with a supporting structure adjacent to the sources of thermal energy (200);

- fluidly coupling the thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22), according to the thermodynamic cycle, with one another and/or with one or more primary heat exchangers (220) in heat exchange relationship with the sources of thermal energy (200).

57. The method of claim 56, wherein the plurality of thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22) further comprises one or more thermal storage systems (40).

58. The method of claim 56 or 57, wherein the step of mechanically cou- pling the thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 40) with one another and/or with a supporting structure adjacent to the sources of thermal energy (200) comprises centering the thermodynamic machines (13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 40) with centering mechanical devices.

59. The method of one or more of claims 56-58, wherein the structural frame (160) and/or the plurality of structural frames (160’, 160”, 160’”) comprise a seat for the one or more primary heat exchangers (220) and wherein the method comprises a step of arranging the one or more primary heat exchangers (220) on the structural frame (160) or on one of the plurality of structural frames (160’, 160”, 160’”).