Heat pump provided integrally with a nuclear power plant

Abstract

An integrated nuclear heat pump system includes a nuclear power plant including reactor coolant and can be configured to generate electricity. The system additionally includes a heat pump including a refrigerant as a working fluid. The heat pump is provided integrally with the nuclear power plant so as to be in thermal contact with at least the reactor coolant. The electricity generated at the nuclear power plant may be used to drive the heat pump. This system helps generate heat for industrial applications.

Description

Technical Field

[0001] The present disclosure relates to a heat pump provided integrally with a nuclear power plant. The heat pump can be configured to be driven by electric power output from an integrally provided nuclear power plant (or another nuclear power plant). The heat pump is configured to thermally interact with the reactor coolant from the nuclear power plant with the heat pump fluid / refrigerant of the heat pump (e.g., indirect cycle), or to directly utilize the reactor coolant as the heat pump fluid / refrigerant of the heat pump (e.g., direct cycle).

Background Art

[0002] A heat pump is configured to transfer thermal energy from one location to another. In particular, a heat pump can transfer heat from a colder heat source to a warmer heat sink. The cycle of the heat pump can operate in either the forward or reverse direction. As a result, if the purpose is to warm the heat sink, the heat pump may be called a heater. Conversely, if the purpose is to cool the heat source, the heat pump may be called a cooler. In any situation, heat is transferred from a colder location to a warmer location via the heat pump.

Summary of the Invention

Means for Solving the Problems

[0003] At least one embodiment relates to an integrated nuclear heat pump system. In an exemplary embodiment, the system includes a nuclear power plant containing reactor coolant and configured to generate electricity, and a heat pump containing a heat pump fluid or refrigerant as a working fluid, the heat pump being provided integrally with the nuclear power plant so as to be at least thermally in contact with the reactor coolant, and the electricity generated by the nuclear power plant can be used to drive the heat pump. Here, the term "heat pump fluid" may be used, or the term "refrigerant" may be used. It should be understood that the terms "heat pump fluid" and "refrigerant" are interchangeable and refer to the same fluid.

[0004] In a system according to an additional embodiment, the nuclear power plant can be configured such that the reactor coolant is not utilized for mechanical work before thermally contacting the heat pump.

[0005] In a system according to another embodiment, the nuclear power plant can be configured such that the reactor coolant passes through a turbine before thermally contacting the heat pump.

[0006] In a system according to another embodiment, the nuclear power plant and the heat pump can be configured such that the reactor coolant thermally contacts the heat pump fluid / refrigerant in a heat exchanger (e.g., indirect cycle) before the heat pump fluid / refrigerant undergoes compression (e.g., single-stage or multi-stage) to achieve a desired temperature rise.

[0007] In a system according to another embodiment, the nuclear power plant and the heat pump are configured such that the desired elevated temperature of the refrigerant is higher than the steam temperature of the reactor coolant from the nuclear power plant.

[0008] In a system according to another embodiment, the desired elevated temperature of the refrigerant may be greater than twice the steam temperature of the reactor coolant from the nuclear power plant.

[0009] In a system according to another embodiment, the heat pump may be configured such that the refrigerant is intercooled between stages of a multistage compression.

[0010] In a system according to another embodiment, the heat pump may be configured such that the refrigerant is intercooled by saturated vapor.

[0011] In a system according to another embodiment, the heat pump may be configured such that the refrigerant is intercooled by an intercooler.

[0012] In a system according to another embodiment, the heat pump may be configured such that the refrigerant is intercooled by an intercooler and saturated vapor.

[0013] In a system according to another embodiment, the heat pump may be configured to supply refrigerant at an elevated desired temperature to a once-through steam generator (OTSG) for heating an industrial process fluid.

[0014] In a system according to another embodiment, the heat pump may be configured to expand the refrigerant exiting the once-through steam generator (OTSG) to obtain a saturated liquid and saturated vapor separated from the saturated liquid.

[0015] In a system according to another embodiment, the heat pump may be configured to utilize the saturated vapor for intercooling the refrigerant between stages of a multistage compression.

[0016] In a system according to another embodiment, the refrigerant may be R-718.

[0017] In a system according to another embodiment, the heat pump may be configured to operate in a closed loop cycle (e.g., an indirect cycle) such that the refrigerant thermally interacts with the reactor coolant without physically mixing. With respect to the "closed loop cycle", it should be understood that the reactor coolant is supplied from the reactor and returns to the reactor after the heat pump.

[0018] In a system according to a further embodiment, the heat pump may be configured to operate in a closed loop cycle (e.g., a direct cycle) that utilizes the reactor coolant from a nuclear power plant as the refrigerant of the heat pump.

[0019] At least one embodiment relates to a method of generating heat for industrial use. In an exemplary embodiment, the method comprises providing a nuclear power plant integrally with a heat pump, the nuclear power plant including a reactor coolant and being configured to generate electricity, the heat pump including a refrigerant as a working fluid, providing the nuclear power plant integrally with the heat pump, harnessing the thermal energy of the reactor coolant from the nuclear power plant for the heat pump, using the electricity generated by the nuclear power plant to compress (e.g., single-stage or multi-stage) the refrigerant within the heat pump so as to obtain a refrigerant at a desired elevated temperature, and using the refrigerant at the desired elevated temperature to heat a process fluid for industrial use.

[0020] In an additional embodiment, the method may further comprise intercooling the refrigerant between stages of the multi-stage compression.

[0021] In a method according to another embodiment, the industrial use may be steam assisted gravity drainage (SAGD).

[0022] In a method according to a further embodiment, steam assisted gravity drainage (SAGD) may be used to extract hydrocarbon fuel.

[0023] In a method according to a further embodiment, the industrial use may be a steam process such as drying of pulp and paper, hydrothermal separation in petrochemical applications, or other industrial uses of high temperature steam. BRIEF DESCRIPTION OF THE DRAWINGS

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0025] The various features and advantages of the non-limiting embodiments herein will become more apparent by considering the detailed description in conjunction with the accompanying drawings. The accompanying drawings are provided for illustrative purposes only and should not be construed as limiting the scope of the claims. The accompanying drawings are not considered to be drawn to scale unless explicitly stated otherwise. For clarity, various dimensions in the drawings may be exaggerated.

[0026] Examples according to several detailed embodiments are disclosed herein. However, the specific structural and functional details disclosed herein are merely representative for the purpose of describing exemplary embodiments. However, the exemplary embodiments may be embodied in a plurality of alternative forms and should not be construed as limited to only the exemplary embodiments described herein.

[0027] Accordingly, the exemplary embodiments are capable of various changes and alternative forms, which are illustratively shown in the drawings and described in detail herein. However, it is not intended to limit the exemplary embodiments to the specific forms disclosed, and on the contrary, it should be understood that the exemplary embodiments cover all modifications, equivalents, and alternatives thereof. Like reference numerals refer to like elements throughout the description of the drawings.

[0028] When an element or layer is referred to as being "on," "connected to," "coupled to," "attached to," "adjacent to," "covering," etc. another element or layer, it may be directly on, connected to, coupled to, attached to, adjacent to, covering, etc. the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly connected to," "directly coupled to" another element or layer, there are no intervening elements or layers. Like reference numerals refer to like elements throughout this specification. As used herein, the term "and / or" includes any and all combinations or sub-combinations of one or more of the associated listed items.

[0029] In this specification, terms such as first, second, third, etc. may be used to describe various elements, regions, layers, and / or sections, but it should be understood that these elements, regions, layers, and / or sections should not be limited by these terms. These terms are only used to distinguish one element, region, layer, or section from another region, layer, or section. Thus, without departing from the teachings of the exemplary embodiments, the first element, region, layer, or section described hereinafter can be referred to as the second element, region, layer, or section.

[0030] Spatially relative terms (e.g., "beneath," "below," "lower," "above," "upper," etc.) are used herein for ease of description to explain the relationship of one element or feature to another (or others) as shown in the drawings. It should be understood that spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings. For example, if the device in the figures is turned over, an element described as "beneath" or "under" another element or feature will be oriented "above" the other element or feature. Thus, the term "beneath" can encompass both orientations, above and below. The device may be in other orientations (rotated 90 degrees or otherwise), and the spatially relative descriptors used herein are to be interpreted accordingly.

[0031] The terms used in this specification are for the purpose of describing various exemplary embodiments only and are not intended to be limiting. As used in this specification, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "includes," "including," "comprises," and / or "comprising," when used in this specification, specify the presence of the stated features, integers, steps, operations, and / or elements, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or groups thereof.

[0032] It should be understood that there may be some inaccuracies when the terms "same" or "identical" are used in the description of the exemplary embodiments. Thus, when an element or value is referred to as being the same as another element or value, that element or value should be understood to be the same as the other element or value within the manufacturing or operational tolerances.

[0033] As used herein, when the terms "about" or "substantially" are used in connection with a numerical value, the associated numerical value is intended to include manufacturing or operational tolerances (e.g., ±10%) above and below the recited numerical value. Further, when the terms "generally" or "substantially" are used in connection with a geometric shape, exactness of the geometric shape is not required, but the degree of freedom of the shape is intended to be within the scope of the present disclosure. Further, regardless of whether a numerical value or shape is modified as "about", "generally", or "substantially", it will be understood that these numerical values and shapes should be construed to include manufacturing or operational tolerances (e.g., ±10%) around the recited numerical values and shapes.

[0034] Unless otherwise defined specifically, all terms (including technical and scientific terms) used herein shall have the same meaning as commonly understood by one of ordinary skill in the art to which the exemplary embodiments belong. Further, terms including those defined in commonly used dictionaries shall be construed to have a meaning consistent with the meaning in the context of the relevant art and shall not be construed in an idealized or overly formal sense unless expressly so defined herein.

[0035] The processing circuit may be hardware including a logic circuit, a combination of hardware / software such as a processor that executes software, or a combination thereof. For example, more specifically, the processing circuit may be, but is not limited to, a central processing unit (CPU), an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a system on chip (SoC), a programmable logic unit, a microprocessor, an application specific integrated circuit (ASIC), etc.

[0036] Unless otherwise specified or apparent from the discussion, terms such as "processing" or "operation" or "calculation" or "decision" or "display" refer to the actions and processes of a computer system or similar electronic computing device that manipulate and transform data represented as physical electronic quantities within the registers and memories of the computer system into other data similarly represented as physical quantities within the memories or registers of the computer system or other similar information storage, transmission, or display devices.

[0037] In the following description, exemplary embodiments may be described with reference to acts of operation and symbolic representations (e.g., in the form of flowcharts, flow diagrams, data flow diagrams, structural diagrams, block diagrams, etc.) that may be implemented as program modules or functional processes including routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The acts are implemented using the existing hardware of an existing electronic system such as one or more microprocessors, central processing units (CPUs), digital signal processors (DSPs), application specific integrated circuits (ASICs), SoCs, field programmable gate arrays (FPGAs), computers, etc.

[0038] One or more exemplary embodiments are (or include) hardware, firmware, hardware that executes software, or any combination thereof. Such hardware includes one or more microprocessors, CPUs, SoCs, DSPs, ASICs, FPGAs, computers, etc. configured as special-purpose machines for performing the functions described herein and any other well-known functions of these elements. In at least some cases, CPUs, SoCs, DSPs, ASICs, and FPGAs may generally be referred to as processing circuits, processors, and / or microprocessors.

[0039] The process may be described with respect to sequential operation, but multiple operations may be performed in parallel, concurrently, or simultaneously. Further, the order of the operations may be rearranged. The process may end when its operations are completed, but may also have additional steps not included in the drawings. The process corresponds to a method, function, procedure, subroutine, subprogram, etc. When the process corresponds to a function, its end corresponds to the return value of the function to the calling function or main function.

[0040] As may be disclosed herein, the terms "memory medium", "computer-readable storage medium", or "non-transitory computer-readable storage medium" may represent one or more devices for storing data, which includes read-only memory (ROM) for storing information, random access memory (RAM), magnetic RAM, core memory, magnetic disk storage media, optical storage media, flash memory devices, and / or other tangible machine-readable media. The term "computer-readable medium" includes, but is not limited to, portable or fixed storage devices, optical storage devices, and various other media capable of storing, storing, or transporting instructions (s) and / or data.

[0041] Furthermore, at least a portion of the exemplary embodiments can be implemented by hardware, software, firmware, middleware, microcode, a hardware description language, or any combination thereof. When implemented in software, firmware, middleware, or microcode, the program code or code segments for performing the necessary tasks can be stored in a machine or computer-readable medium such as a computer-readable storage medium. When implemented in software, the processor(s), processing circuit(s), or processing unit(s) can be programmed to perform the necessary tasks, thereby transforming into a special-purpose processor(s) or computer(s).

[0042] A code segment can represent any combination of a procedure, function, subprogram, program, routine, subroutine, module, software package, class, or instructions, data structures, or program statements. A code segment can be coupled to another code segment or a hardware circuit by passing information, data, arguments, parameters, or memory contents. The information, arguments, parameters, data, etc. can be passed, transferred, or transmitted via any suitable means including memory sharing, message passing, token passing, network transmission, etc.

[0043] A nuclear reactor causes and controls a nuclear chain reaction and may be used in a nuclear power plant for power generation. An example of such a nuclear reactor is a boiling water reactor (BWR). In a boiling water reactor, heat is generated by nuclear fission in the reactor core, and liquid water is used as the coolant. The heat from the reactor core boils the liquid water into steam, and the steam is then directly used to drive a turbine. Subsequently, the steam is cooled in a condenser and converted back into liquid water, which is then returned to the reactor core as part of a continuous loop during the operation of the reactor. Another example of a related nuclear reactor is a pressurized water reactor (PWR). In a pressurized water reactor, liquid water is used as the coolant, but it is exposed to high pressure so that bulk boiling does not occur. The hot water is then used to produce steam in a steam generator. Alternatively, the hot water may be used to heat a process fluid directly before it enters a cycle heat pump or to heat a refrigerant that indirectly heats the process fluid.

[0044] According to an exemplary embodiment, the steam from the nuclear reactor can be used in connection with another industrial process or in another way to provide assistance. Disclosed herein is a novel method of using the steam output from a nuclear reactor to produce higher temperature steam or other process fluids. Light water cooled nuclear reactors typically generate steam at 523 - 570°F (about 272.778°C to about 298.889°C) from the reactor vessel (BWR) or steam generator (PWR). However, in many process heat applications, it is necessary to heat the process fluid at higher temperatures and pressures than those that these reactors can provide.

[0045] At least one of an electric heater and the combustion of fuel can be used to further heat a process fluid that exceeds the temperature of the steam generated by the nuclear reactor. However, such methods require electricity costs or fuel costs necessary for operation and generate exhaust gases due to combustion.

[0046] This system transfers the thermal energy remaining in the reactor steam output directly (via a heat pump) or, after using it for mechanical work with a steam turbine(s), to a higher temperature process fluid, leveraging the advantages of subcritical or supercritical thermodynamic cycles. For example, refer to Figure 1 (a non-limiting example of industrial applications including SAGD). A nuclear power plant integrated with a heat pump may or may not be configured to generate electricity. When the integrated nuclear power plant is configured to generate electricity, that power is used to drive the heat pump. For example, the nuclear power plant can be configured such that the reactor coolant is used for mechanical work (e.g., driving a steam turbine) for power generation (e.g., driving the heat pump) before it comes into thermal contact with the heat pump. In such an example, a small portion (e.g., 20% or less, 10% or less) of the reactor coolant can be used for mechanical work (e.g., a steam turbine), and a large portion (e.g., 80% or more, 90% or more) of the reactor coolant can be used for thermal work (e.g., a heat pump).

[0047] However, in other examples, multiple reactors / nuclear power plants may be co-located with the heat pump, or other power sources (e.g., gas turbines, wind power generation, solar power generation, etc.) may be co-located with the heat pump. In such cases, a reactor / nuclear power plant integrated with the heat pump may not have a steam turbine and thus may not be configured to generate electricity, even if it is thermally connected. As a result, power from another co-located power source can be used to drive the heat pump. At least two different exemplary embodiments and their variations are described in this application. It should be understood that although Figure 1 is shown in relation to steam-assisted gravity drainage (SAGD) for oil production, the exemplary embodiments are not limited thereto.

[0048] It is novel to integrally provide a heat pump (for example, single-stage or multi-stage) with at least one of a boiling water reactor (BWR) and a pressurized water reactor (PWR) nuclear power plant. By integrally providing it, by utilizing the heat of the reactor coolant in the heat pump cycle, the overall cycle efficiency of the cogeneration process (heat and electricity) is improved. An alternative is to use at least one of an electric heater (which consumes more power) and a natural gas boiler (which emits CO2).

[0049] Disclosed herein is an epoch-making method of directly or indirectly using nuclear power steam as the R-718 refrigerant made entirely of water in the application of a heat pump.

[0050] It is novel to use a supercritical (or subcritical) steam cycle in a heat pump. In order to improve the COP (coefficient of performance) and minimize the cost of the heat pump, the critical cycle was carefully selected. The heat transfer occurring in the two-phase region helps to increase the COP. Finally, the selection of steam as the heat pump fluid was not obvious to those skilled in the art. Steam has thermodynamic properties (critical point temperature) suitable for the desired temperature rise within the heat pump, but usually, steam is not utilized in heat pump applications and is not usually mechanically compressed as disclosed herein.

[0051] The use of a multi-stage intercooler heat pump is also novel. A multi-stage compressor is required for the temperature rise expected in the heat pump. Furthermore, novel approaches such as intercooling were incorporated into the design to reduce the power of the compressor.

[0052] Finally, new approaches such as the use of expanders are being considered to reduce costs without sacrificing efficiency. The expander may be a turbine expander or a non-turbine expander. Each expander stage can be a turbine expander, an expansion valve, or other pressure-reducing devices such as a capillary tube. By this one or series of expander stages, the temperature of the heat pump fluid is reduced, thereby making it more possible to absorb heat from the reactor steam during downstream heat exchange.

[0053] In Embodiment 1, in a closed-loop heat pump cycle, refrigerant R-718 in the form of two-phase vapor is circulated. However, it should be understood that the refrigerant is not limited to this, and may include other heat pump fluids (e.g., CO2). For an example of a three-stage vapor compression heat pump with inter-stage vapor separation, refer to FIG. 2. Referring to FIG. 2, the refrigerant (heat pump fluid) in state 10 passes through a heat exchanger and receives heat from the reactor coolant (a lower temperature heat source). The heat pump fluid is heated to near its vapor saturation line (state 1). The heat pump fluid is then compressed (from state 1 to state 2), and optional intercooling (from state 2 to state 3) is performed using the vapor 9V separated in the expansion process. The heat pump fluid can undergo one or a series of these compression and optional vapor-based intercooling stages (if necessary) until the temperature of the heat pump fluid is higher than the process fluid temperature (a higher temperature heat sink). In the example shown in FIG. 2, three stages of compression and intercooling are shown: · Heat pump stage 1 → from state 1 to state 2 (compression), and then to state 3 (after intercooling) · Heat pump stage 2 → from state 3 to state 4 (compression), and then to state 5 (after intercooling) · Heat pump stage 3 → from state 5 to state 6 (compression)

[0054] As a result, the resulting fluid becomes significantly hotter than the steam from the reactor and can be used for process heating, either directly or by heating another fluid. From state 6 to state 7, the heat pump fluid passes through a heat exchanger that supplies heat to a process application (a hotter heat sink). As an example of a process application, the heat pump fluid can be used to heat a process fluid in an OTSG (once-through steam generator). From state 7 to state 10, the heat pump fluid expands through a partial or complete series of expander stages within the liquid-vapor dome (see the T-s diagram in Figure 2). After the expansion stages (states 8, 9, and 10), the saturated vapor and saturated liquid can be separated. Also, the saturated vapor can be used for any intercooling between compression stages. The saturated liquid undergoes the next expansion stage until it reaches the lower limit temperature at state 10. In Embodiment 1, any intercooling is achieved by the saturated vapor separated after each expansion stage. In other embodiments, the compression intercooling can be replaced by an intercooling heat exchanger (see Figure 3), supplemented by an intercooling heat exchanger (see Figure 4), or replaced by the injection of saturated vapor from an external source (e.g., saturated steam). The intercooling heat exchanger is also called an intercooler.

[0055] Embodiment 1 and its variations improve the coefficient of performance of the cycle by introducing several components as follows: 1. In this embodiment, a single-stage or multi-stage steam compressor with intercooling between one or more stages can be utilized. This compressor operates between 1,000 and 40,000 RPM under design conditions and provides a pressure ratio of 1.5 to 40. This compressor has a radial compressor stage, or a mixed stage, or an axial stage. This compressor compresses the heat pump fluid and raises its pressure and temperature. 2. One expander or a series of expanders reduces the pressure of the heat pump fluid returning from process applications and heat removal. This expander operates fully or partially within the saturated liquid-vapor dome of the heat pump fluid (see the T-s diagrams of FIGS. 2, 3, and 4). Each expander stage can be a turbine expander, an expansion valve, or other pressure-reducing devices such as a capillary tube. Due to this one or series of expander stages, the temperature of the heat pump fluid is reduced, thereby allowing more heat absorption from the reactor steam during state 10. 3. Various types of heat exchangers can be used for heat transfer from the reactor coolant to the heat pump fluid. Suitable types include vapor-vapor heat exchangers with two-phase fluids on both sides of the heat exchanger. 4. Various types of heat exchangers can be used for heat transfer from the heat pump fluid to the process fluid. In a non-limiting embodiment, a once-through steam generator (OTSG) can be utilized to heat the process steam fluid using the heat pump fluid (vapor) from the compressor outlet. 5. In a variant of this embodiment, a separator for separating saturated vapor and saturated liquid exists after one or more stages of expansion. 6. In a variant of this embodiment, a sprayer is provided between one or more stages of the compressor to intercool the flow between compression stages. The sprayer may or may not be connected to a separator (if any) after the expander(s). 7. In a variant of this embodiment, one or more intercooling heat exchangers for transferring heat from the heat pump fluid to process applications are utilized.

[0056] The concept of heat pump steam boosting can be made more flexible for various operating scenarios, improve cycle efficiency, and increase the temperature difference between the heat source (reactor coolant steam) and the heat sink (process steam) by improving cycles such as: · Multiple heat absorption heat exchangers for receiving heat from multiple heat sources · Multiple compression stages or multiple compressors · A plurality of expanders operating in a mixed-phase region (e.g., at least one of a non-turbine expander and a turbine expander) · A plurality of intercoolers between compression stages for maintaining the heat pump fluid in a state close to the vapor saturation line · For driving the compressor, a steam-driven mechanical drive turbine can also be used.

[0057] In Embodiment 2, the reactor coolant (steam) is directly used in the heat pump cycle. For an example of a three-stage vapor compression heat pump and a direct cycle with inter-stage vapor separation, refer to FIG. 5. The reactor coolant fluid (steam) enters the cycle in a state close to its vapor saturation line (State 1). Since the following compression process, heat exchange process, and expansion process are the same as those in Embodiment 1, they will be briefly described below. The heat pump fluid is subsequently compressed (from State 1 to State 2), and optional intercooling (from State 2 to State 3) is performed using the vapor 9V separated in the expansion process. The heat pump fluid can undergo one stage or a series of this compression and optional steam-based intercooling stages (if necessary) until the temperature of the heat pump fluid becomes higher than the process fluid temperature (higher-temperature heat sink). As a result, the resulting fluid becomes significantly hotter than the steam from the reactor and can be used for process heating by directly heating or heating another fluid. From State 6 to State 7, the heat pump fluid passes through a heat exchanger that supplies heat to a process application (higher-temperature heat sink). An example of a process application is an OTSG (once-through steam generator). From State 7 to State 10, the heat pump fluid expands through a partial or complete series of expander stages within the liquid-vapor dome (refer to the T-s diagram in FIG. 2). After the expansion stages (States 8, 9, and 10), the saturated vapor and saturated liquid can be separated. Also, the saturated vapor can be used for any intercooling between compression stages. The saturated liquid undergoes the next expansion stage until it reaches the lower limit temperature of State 10. Finally, the reactor coolant returns to the reactor as a sub-cooled liquid (State 11).

[0058] In Embodiment 2, intercooling is achieved by the saturated vapor separated after each expansion stage. In other embodiments, the compression intercooling can be replaced by an intercooling heat exchanger, supplemented by an intercooling heat exchanger (see Embodiment 2 of FIG. 6), or replaced by spraying saturated vapor from an external source. As described above, the intercooling heat exchanger may also be referred to as an intercooler.

[0059] Embodiment 2 and its variants improve the coefficient of performance of the cycle by introducing several components as follows: 1. Embodiment 2 can utilize a single-stage or multi-stage steam compressor, and optionally intercooling can be utilized between one or more stages. In this Embodiment 2, the heat pump fluid and the reactor coolant are the same. This compressor operates between 1,000 and 40,000 RPM under design conditions and provides a pressure ratio of 1.5 to 40. This compressor has a radial compressor stage, or a mixed stage, or an axial stage. This compressor compresses the heat pump fluid and raises its pressure and temperature. 2. One expander or a series of expanders reduces the pressure of the heat pump fluid returning from the process application and heat removal. Again, in this Embodiment 2, the heat pump fluid and the reactor coolant are the same. This expander operates completely or partially within the saturated liquid-vapor dome of the heat pump fluid (see the T-s diagrams of FIGS. 5 and 6). Each expander stage can be a turbine expander, an expansion valve, or other pressure-reducing devices such as a capillary tube. Due to this stage of one or a series of expanders, the temperature of the heat pump fluid is reduced, allowing for more heat absorption subsequently. 3. For heat transfer from the heat pump fluid to the process fluid, various types of heat exchangers can be utilized. In a non-limiting embodiment, a once-through steam generator (OTSG) can be utilized to heat the process steam fluid using the heat pump fluid (vapor) from the compressor outlet. 4. In a variant of this embodiment, a separator for separating saturated vapor and saturated liquid is present after one or more stages of expansion. 5. In a variant of this embodiment, a sprayer is provided between one or more stages of the compressor to intercool the flow between the compression stages. The sprayer may or may not be connected to a separator (if any) after the expander(s). 6. In a variant of this embodiment, one or more intercooling heat exchangers for transferring heat from the heat pump fluid to a process application are utilized.

[0060] The concept of the heat pump type steam boost can be made more flexible for various operating scenarios, improve the cycle efficiency, and increase the temperature difference between the heat source (reactor coolant steam) and the heat sink (process steam) by improving the cycle as follows: · Multiple compression stages or multiple compressors · Multiple expanders (e.g., at least any one of a non-turbine expander and a turbine expander) operating fully or partially in the mixed phase region (i.e., the saturated liquid-vapor dome of the heat pump fluid in the T-s diagram) · Multiple intercoolers between compression stages for keeping the heat pump fluid (which is also a nuclear coolant) in a state close to the vapor saturation line · For driving the compressor, a steam-driven mechanical drive turbine can also be used.

[0061] Although multiple exemplary embodiments are disclosed in this specification, it should be understood that other variations are possible. Such variations are not considered to depart from the spirit and scope of this disclosure, and all such modifications that would be obvious to those skilled in the art are intended to be included in the following claims.

Claims

1. An integrated nuclear heat pump system, a nuclear power plant including a reactor coolant, a heat pump including a refrigerant as a working fluid, the heat pump being provided integrally with the nuclear power plant so as to be in thermal contact with at least the reactor coolant, An integrated nuclear heat pump system comprising:

2. The integrated nuclear heat pump system according to claim 1, wherein the nuclear power plant is configured to generate electricity to drive the heat pump such that the reactor coolant passes through one or more turbines for power generation before coming into thermal contact with the heat pump.

3. The integrated nuclear heat pump system according to claim 1, wherein the nuclear power plant is configured such that the reactor coolant is not used for mechanical work before coming into thermal contact with the heat pump, and power from another power source is used to drive the heat pump.

4. The integrated nuclear heat pump system according to claim 1, wherein a small portion of the reactor coolant is used for mechanical work for power generation, and a majority of the reactor coolant is used for thermal work related to the heat pump.

5. The integrated nuclear heat pump system according to claim 1, wherein the heat pump is configured to operate in an indirect cycle such that the refrigerant thermally interacts with the reactor coolant without physically interacting therewith.

6. The integrated nuclear heat pump system according to claim 1, wherein the heat pump is configured to operate in a direct cycle such that the reactor coolant from the nuclear power plant is directly used as the refrigerant of the heat pump.

7. The integrated nuclear heat pump system according to claim 1, wherein the nuclear power plant and the heat pump are configured such that the reactor coolant comes into thermal contact with the refrigerant before the refrigerant is subjected to multi-stage compression, thereby obtaining a desired elevated temperature.

8. The integrated nuclear heat pump system according to claim 7, wherein the heat pump is configured such that the refrigerant is intercooled between stages of the multi-stage compression.

9. The integrated nuclear heat pump system according to claim 8, wherein the heat pump is configured such that the intercooling is performed using at least one of an intercooling heat exchanger or saturated vapor.

10. The integrated nuclear heat pump system according to claim 7, wherein the heat pump is configured to supply the refrigerant at the elevated desired temperature to a once-through steam generator (OTSG) for heating a process fluid for industrial use.

11. The integrated nuclear heat pump system according to claim 7, wherein the heat pump is configured to expand the refrigerant at the elevated desired temperature after applying it to an industrial use to obtain a saturated liquid and saturated vapor separated from the saturated liquid.

12. The integrated nuclear heat pump system according to claim 11, wherein the heat pump is configured such that the saturated vapor is utilized to intercool the refrigerant between stages of the multi-stage compression.

13. The integrated nuclear heat pump system according to claim 7, wherein the heat pump is configured to expand the refrigerant at the elevated desired temperature after applying it to an industrial use using at least one of a turbine expander, an expansion valve, or a capillary tube.

14. The integrated nuclear heat pump system according to claim 1, wherein the heat pump is configured such that the refrigerant undergoes a cycle above critical or below critical.

15. The integrated nuclear heat pump system according to claim 1, wherein the refrigerant is R-718 or carbon dioxide.

16. A method for generating heat for industrial use, comprising: providing a nuclear power plant integrally with a heat pump, wherein the nuclear power plant includes a reactor coolant and is configured to generate electricity, and the heat pump includes a refrigerant as a working fluid; utilizing the thermal energy of the reactor coolant exiting the nuclear power plant in the heat pump; performing compression of the refrigerant in the heat pump using electricity generated by the nuclear power plant so as to obtain an elevated desired temperature of the refrigerant; and heating a process fluid for industrial use using the refrigerant at the elevated desired temperature. A method for generating heat for industrial use, including... **Claim 17** In the step of integrally providing the nuclear power plant with a heat pump, the heat pump is configured to operate in a direct cycle that directly utilizes the reactor coolant from the nuclear power plant as the refrigerant of the heat pump. The method according to claim 16. **Claim 18** The compression is multi-stage compression, The method according to claim 16, further comprising the step of inter-cooling the refrigerant between stages of the multi-stage compression. **Claim 19** The method according to claim 16, wherein the industrial use includes at least steam-assisted gravity drainage (SAGD), petrochemical production, or paper production. **Claim 20** The method according to claim 19, wherein the steam-assisted gravity drainage (SAGD) is used for extracting hydrocarbon fuels.

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