Energy storage coupling heat pump steam generation system

Abstract

The utility model provides an energy storage coupling heat pump steam generation system, which adopts a mode of cooperative operation of a heat pump device and an energy storage device to realize efficient and economical steam supply. According to the system, high-temperature water is prepared and stored in the valley electricity period through the heat pump device, and the high-temperature water is further heated through the energy storage device to generate superheated steam for a user to use. The energy storage device comprises a plurality of energy storage modules, and a heat exchange pipeline of the energy storage device can be switched between a parallel connection mode and a series connection mode through switching, so that deep heat release and flexible regulation and control are achieved. The system further performs preheating or dynamic supplement on the energy storage module through the heat pump device, waste heat recovery is achieved, and the energy efficiency is improved. According to the utility model, the operation cost is obviously reduced, the capability of adapting to load fluctuation of the system is enhanced, and the system is suitable for industrial steam use scenes and has the characteristics of high efficiency, stability and flexibility.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the field of energy utilization and energy storage technology relates to a kind of energy storage coupling heat pump steam generation system, especially a kind of comprehensive system for preparing high-temperature water by heat pump high efficiency and further heating high-temperature water into steam by energy storage module. BACKGROUND

[0002] With the promotion of energy-saving and emission-reducing policy, industrial production demands for efficient and clean steam heating system are increasing. Traditional combustion boilers are gradually replaced by more environmentally friendly electric heating and energy storage technology due to their low efficiency and high carbon emissions. However, existing electric heating and energy storage systems still have limitations in energy efficiency and operational flexibility. For example, systems that rely solely on electric heating have low energy efficiency and high operating costs. The heat release depth of the energy storage module is insufficient, resulting in low heat utilization efficiency. In addition, under the condition of peak-valley electricity price, the valley electricity is not fully utilized for energy storage, which also increases the operating cost of the system.

[0003] In recent years, heat pumps have been widely used in heating systems due to their high energy efficiency. However, in existing technology, the coupling degree of heat pump and energy storage module is insufficient, making it difficult to flexibly adjust the operating mode under different heat demand and electricity price conditions. In addition, the matching of heat capacity and heat release performance of the energy storage module is poor, which limits the further improvement of the overall efficiency and economy of the system. Therefore, there is an urgent need for an efficient, low-cost, and flexible steam generation system to better meet the needs of industrial production and adapt to complex operating conditions. SUMMARY

[0004] The utility model provides a kind of energy storage coupling heat pump steam generation system, and the efficient heating characteristics of heat pump device and the high-density energy storage characteristics of energy storage device are organically combined, the efficient utilization of energy and the flexible satisfaction of heating demand are realized. The utility model utilizes heat pump device to heat water from normal temperature to high-temperature water close to saturation temperature during valley electricity period, and stores in water storage device, then further heats high-temperature water to target steam temperature by energy storage device using molten salt or other efficient heat storage medium, to meet steam demand. In this process, the system realizes the hierarchical efficient utilization of energy, significantly reduces the equipment scale and cost by reducing the heat release burden of the energy storage module. At the same time, the energy storage device supports deep heat release design, fully releases low-grade heat to further improve overall efficiency. In addition, the cooperative operation mode of heat pump and energy storage device can be dynamically adjusted according to electricity price and steam demand, flexibly realizes time peak-shaving, and optimizes the economy and operational reliability of the system. The overall scheme realizes the balance of energy efficiency, cost and applicability through modular design and dynamic control, and can be widely applied to industrial heating scenarios to meet the actual needs of energy-saving and emission-reducing.

[0005] To achieve the above purpose, the utility model adopts the following technical solutions:

[0006] An energy storage coupled heat pump steam generation system, comprising:

[0007] A heat pump device for heating water to a first temperature, the first temperature being a high temperature water temperature close to a saturation temperature;

[0008] An energy storage device comprising at least one energy storage module filled with a thermal storage medium and equipped with a heat exchange pipeline for receiving the high temperature water at the first temperature and further heating to a second temperature through the thermal storage medium to generate a first water vapor.

[0009] As a preferred solution, further comprising:

[0010] A water storage device fluidly connected to the heat pump device for heat-insulated storage of the high temperature water heated to the first temperature by the heat pump device;

[0011] A first feedwater pipeline connecting the water storage device and the energy storage module for delivering the high temperature water in the water storage device to the heat exchange pipeline;

[0012] A pressure stabilizing device connected to the energy storage module, such that the energy storage module supplies the first water vapor to the pressure stabilizing device;

[0013] An attemperator comprising a steam input port connected to the pressure stabilizing device and an attemperating water input port connected to the first feedwater pipeline, the attemperator mixing the water vapor input from the steam input port and the attemperating water input from the attemperating water input port to output a second water vapor at a third temperature, the third temperature being lower than the second temperature.

[0014] As a preferred solution, the water storage device has a sealing and pressurizing function for maintaining the high temperature water above 100°C in a liquid state.

[0015] As a preferred solution, the first feedwater pipeline comprises:

[0016] A feedwater pump group and a main pipe regulating valve group connected in series to the energy storage module;

[0017] An attemperating water branch leading from between the feedwater pump group and the main pipe regulating valve group and connected to the attemperating water input port;

[0018] A recirculation branch leading from between the main pipe regulating valve group and the energy storage module and connected to the water storage device for realizing backflow of the high temperature water when the system is running.

[0019] As a preferred solution, the heat exchange pipelines of multiple energy storage modules are configured to be connected in parallel between any two energy storage modules to form multiple steam generation paths or connected in series to form a single steam generation path through switching operation.

[0020] As a preferred solution, it further comprises a deionized water supply device,

[0021] The deionized water supply device is adapted to supply deionized water to the heat pump device, and / or the energy storage module, and / or the desuperheater input port.

[0022] As a preferred solution, it further comprises a second feedwater line,

[0023] The second feedwater line connects the heat pump device and the energy storage module, and is used to transport high-temperature water generated by the heat pump device to the heat exchange line.

[0024] As a preferred solution, it further comprises a preheating loop, the preheating loop comprising a third feedwater line and a preheating return water line, both of which are connected between the heat pump device and the energy storage module to form a loop, and are used to make the heat pump device heat the thermal storage medium below the first temperature.

[0025] As a preferred solution, the third feedwater line and the preheating return water line are both connected to the heat exchange line, so that the third feedwater line, the heat exchange line, and the preheating return water line are adapted to constitute the preheating loop.

[0026] And / or, the energy storage module is further provided with a preheating line, and the third feedwater line and the preheating return water line are both connected to the preheating line, so that the third feedwater line, the preheating line, and the preheating return water line are adapted to constitute the preheating loop.

[0027] As a preferred solution, the energy storage module comprises an outer cylinder and an inner cylinder, the inner cylinder is arranged in the outer cylinder, the thermal storage medium is arranged between the outer cylinder and the inner cylinder, and the heat exchange line comprises a first heat exchange coil arranged in the outer cylinder and a second heat exchange coil arranged in the inner cylinder.

[0028] As a preferred solution, the first heat exchange coil is a heat exchange coil welded to the inner wall of the outer cylinder, and the second heat exchange coil is a heat exchange coil welded to the outer wall of the inner cylinder.

[0029] As a preferred solution, the second heat exchange coil is also used for preheating the thermal storage medium below the first temperature.

[0030] As a preferred solution, it further comprises:

[0031] A steam line connecting the energy storage module and the pressure stabilizing device, and a mechanical safety valve is arranged on the steam line;

[0032] A steam main pipe connected to the steam outlet of the desuperheater, and an overpressure relief valve is arranged on the steam main pipe;

[0033] A blowdown pipeline is connected with the water supply port of the energy storage module and communicates with a blowdown well, and a blowdown valve is installed on the blowdown pipeline.

[0034] As a preferred solution, when a plurality of energy storage modules are included, a branch valve group is also included, which is arranged between the main valve group and each energy storage module, for adjusting the flow of high-temperature water into each energy storage module.

[0035] As a preferred solution, the heat storage medium includes at least one of a molten salt heat storage medium, a solid heat storage medium, a thermochemical heat storage medium, and a phase change heat storage medium; and / or,

[0036] The heat pump device includes one or more of a waste heat source heat pump, an air source heat pump, a water source heat pump, and a ground source heat pump, and adopts carbon dioxide as a circulating working medium and operates in a transcritical cycle state; and / or,

[0037] The heat pump device is configured to operate through cascade heating.

[0038] As a preferred solution, the energy storage module further includes an auxiliary heater adapted to heat the fluid in the heat exchange pipeline; or,

[0039] The steam generation system further includes an emergency heating module, which includes an emergency heating pipeline in series or parallel with the heat exchange pipeline, for auxiliary heating when the heat release power of the energy storage module is insufficient.

[0040] The above technical solution has at least the following beneficial effects:

[0041] 1. The present utility model combines the efficient heating characteristics of the heat pump device and the high-density energy storage characteristics of the energy storage device, fully utilizes the high energy efficiency advantage of the heat pump under low temperature rise conditions, heats water to high-temperature water close to saturation temperature; then, the energy storage device further heats the high-temperature water to the target steam temperature using high-density heat storage medium, realizes the staged utilization and efficient conversion of energy; this design not only significantly reduces the heat required to be provided by the energy storage device, thereby reducing the size and cost of the energy storage module, but also effectively improves the overall energy efficiency of the system, reduces the power consumption per unit of steam, and enhances the economic efficiency of the system; in addition, the introduction of high-temperature water optimizes the heat transfer conditions, reduces the heat transfer temperature difference between the heat storage medium and water and the system thermal stress, and plays an important role in improving the operation stability and equipment service life of the energy storage device; through the cooperative operation of the heat pump and the energy storage device, the present utility model realizes an efficient, economical, and flexible steam generation process, and meets the diversified needs of industrial production.

[0042] 2.The utility model discloses a heat pump device heats water to high-temperature water close to saturation temperature, and delivers it to a water storage device with sealing and pressurizing functions, which can store high-temperature water without phase change, significantly reducing the safety risk and heat loss caused by high temperature and high pressure of the steam generation system; in addition, since the water storage device maintains the liquid state of high-temperature water, it ensures the efficiency and uniformity of subsequent stable supply of high-temperature water to the energy storage device; further, by setting an accurate temperature difference range (such as 2-10℃) between high-temperature water and saturation temperature, the operating load of the heat pump is optimized, the heat pump energy efficiency is prevented from being reduced due to excessive heating, and the energy storage device is provided with high-temperature water at the optimal temperature; this temperature difference design not only effectively reduces the overall energy consumption of the system, but also reduces the heat transfer temperature difference stress inside the energy storage device, improving the safety of system operation and the service life of the energy storage module; through the synergistic optimization of the heat pump and the energy storage device, the utility model realizes an efficient, stable and safe steam generation process.

[0043] 3.The utility model discloses the flexible combination operation of heat pump and energy storage device, realizes the time peak-shaving of heat supply demand and power consumption; in the valley electricity period, the heat pump concentrates operation and prepares high-temperature water and stores; in the flat electricity or peak electricity period, the energy storage device releases heat to meet the steam demand; this design reduces the direct demand for electricity in the peak period, significantly reduces the operation cost; at the same time, the system supports dynamic adjustment of the operation mode according to the real-time electricity price, transformer capacity and load demand, adapts to various steam demand, and further improves the economy.

[0044] 4.The utility model discloses that the operation strategy can be adjusted in real time according to steam demand and electricity price fluctuation, for example, when the transformer capacity is insufficient in the valley electricity period, the energy storage device is preferentially operated for energy storage, and part of the load of the heat pump is moved to the flat electricity period for operation; when the waste heat resource is sufficient, the heat pump can also be used to preheat the energy storage device, further optimizing the resource utilization efficiency; through the dynamic adjustment strategy driven by real-time data, the optimization of energy use is realized.

[0045] 5.The utility model discloses that the heat exchange pipeline of the energy storage module can realize parallel or series switching, which can provide rapid heating through multiple parallel modes in high steam demand, and can realize deep heat release of molten salt through series mode in low demand, maximizing the utilization efficiency of heat storage medium; further, the heat distribution strategy of the energy storage module in different heat release stages is clear, which can produce target steam temperature and use low-temperature heat storage medium for preheating or generate high-temperature water by adjusting the heat exchange pipeline, effectively prolonging the energy utilization chain in the heat release process; through flexible heat distribution and modular design, not only the dynamic steam demand is met, but also the energy efficiency and operation safety of the system are significantly improved, prolonging the service life of the equipment.

[0046] 6.The energy storage device supports multiple heat storage media, including molten salt, solid energy storage, phase change energy storage, and thermochemical energy storage, etc., and can be flexibly configured according to different heat storage requirements; at the same time, the heat pump device can select multiple types such as waste heat source heat pump, air source heat pump, and ground source heat pump, etc., to adapt to diversified industrial steam scenes; preferably, a transcritical carbon dioxide heat pump can be used in the utility model, which realizes efficient conversion of low-temperature heat source to high-temperature heat carrier through efficient transcritical cycle, and is especially suitable for scenes that need to prepare high-temperature water close to saturation temperature; in addition, the heat pump can further improve the outlet temperature range through cascade heating mode, and meet the high-temperature demand. The heat storage medium is preferably low-melting-point mixed molten salt (melting point below 100 DEG C), which not only reduces the starting temperature requirement of the energy storage system, but also enhances the feasibility and efficiency of deep heat release, maximizing the energy storage capacity. This flexible configuration and optimal design significantly expand the application range of the system, and effectively improve the overall energy efficiency and economy of the system by optimizing the operation configuration for different environmental conditions and production demands, meeting the complex demands of industrial steam.

[0047] 7.The desuperheating water of the utility model is prepared from high-temperature water and supplied to the inlet of the desuperheater through accurate control of flow and temperature, which can flexibly adjust the output steam temperature in the industrial scene with diversified steam demand, and meet the demand of different processes for steam parameters. The introduction of desuperheating water also effectively reduces the thermal stress of steam pipeline and downstream equipment, prolongs the service life of the equipment. In addition, the use of desuperheating water significantly reduces the energy consumption of direct superheated steam, avoiding the waste of excessive heating of steam. The mechanism is that the sensible heat exchange between desuperheating water and steam can quickly balance the steam temperature, and due to the high specific heat of water, a larger temperature adjustment range can be achieved with less flow. Through accurate control of the desuperheater, the utility model not only improves the flexibility and stability of steam supply, but also optimizes the system energy efficiency, reduces the operation cost, and adapts to the diversified steam demand in industrial production.

[0048] 8.The molten salt storage tank of the utility model is designed through the structure of inner and outer cylinders, and the heat exchange coil is arranged on the inner wall of the outer cylinder and the outer wall of the inner cylinder to form an efficient heat exchange system. The design of the inner cylinder is flexible, which can be arranged as multiple concentric structures or independently distributed, and its inside can be filled with different types of molten salt or solid heat exchange materials, or even hollow heat exchange. The outer cylinder heat exchange coil is mainly used for rapid transmission of high-temperature heat, and the inner cylinder heat exchange coil not only realizes deep heat release of molten salt, but also preheats the molten salt by using a heat pump during off-peak hours, effectively reducing the system startup time. This structure enhances the uniformity of heat distribution of molten salt, avoids excessive temperature difference, and improves the heat release power and energy efficiency of the storage tank. At the same time, the flexibility of the inner cylinder structure improves the ability of the storage tank to adapt to different heat requirements and operating scenes, making the system run more efficiently, stably and flexibly.

[0049] 9.The branch valve group of the utility model is used for precisely adjusting the water inflow into each energy storage module, making the heat release process of the energy storage module uniform, avoiding local overheating or heat release efficiency reduction caused by uneven flow. In addition, when the steam pressure fluctuates, the system adjusts the flow through the feedwater main valve and the recirculation pipeline in time to stabilize the pressure, ensuring the stability of steam supply. This flow regulation mechanism not only improves the energy efficiency utilization rate of the energy storage module, but also enhances the flexibility and reliability of the system, effectively adapting to different load requirements and operating conditions.

[0050] 10.The utility model discloses through four stage pressure early warning design, the safety and stability of system operation are improved obviously. When the steam pressure fluctuates, the first early warning is through adjusting the feedwater main valve group and recirculation pipeline, and the pressure is stabilized by quick response; The second early warning is through the overpressure relief valve after opening the desuperheater, and the pressure is relieved by exhausting the steam; When the third early warning, the system enters the emergency shutdown state, and the working medium in the energy storage module is discharged through the blowdown pipeline to reduce the pressure quickly; The fourth early warning is through the automatic take-off of the mechanical safety valve, to ensure that the system and equipment are not damaged in extreme conditions. This multistage pressure early warning mechanism is progressive, which not only realizes the accurate control of pressure regulation, but also provides multiple safety protection for system operation, significantly reduces the risk caused by overpressure, and prolongs the service life of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical scheme in the embodiments of the utility model, the following will briefly introduce the drawings needed to be used in the embodiments and their marks. Obviously, the drawings described below are only some embodiments of the utility model, and those skilled in the art can obtain other drawings according to these drawings without creating any creative labor.

[0052] Figure 1 It is the structure schematic view of the energy storage coupled heat pump steam generating system of an embodiment of the utility model;

[0053] Figure 2 It is the structure schematic view of the energy storage module of an embodiment of the utility model;

[0054] Figure 3 It is Figure 2 It is the structure schematic view of the outer cylinder of the energy storage module and the first heat exchange pipeline;

[0055] Figure 4 It is the flow chart of the energy storage coupled heat pump steam generating method described in the embodiment of the utility model;

[0056] Figure 5 It is the flow chart of the general heat charging and releasing cycle of the energy storage module described in the embodiment of the utility model;

[0057] Figure 6A flow chart of the energy storage coupling heat pump steam generation method according to the embodiment of the present application.

[0058] Figure 7 A flow chart of the steam generation process according to the embodiment of the present application.

[0059] Figure 8 A flow chart of the charge and discharge cycle of the energy storage module with deep heat release according to the embodiment of the present application.

[0060] The meanings of the symbols in the figures are as follows:

[0061] 11 - raw water tank, 12 - water treatment device, 13 - pure water tank, 20 - heat pump device, 30 - water storage device, 41 - recirculation branch, 42 - desuperheating water branch, 43 - blowdown pipeline, 44 - steam pipeline, 50 - energy storage module, 51 - electric heater, 52 - first heat exchange pipeline, 53 - second heat exchange pipeline, 60 - steam distribution cylinder, 70 - desuperheater, 81 - mechanical safety valve, 82 - overpressure relief valve. DETAILED DESCRIPTION

[0062] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the specific embodiments of the present application will be described below with reference to the drawings. Obviously, the drawings described below are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained from these drawings without creative labor, and other embodiments can also be obtained.

[0063] In order to make the drawing simple, only the parts related to the present application are shown in each drawing, which does not represent the actual structure of the product. In addition, in order to make the drawing simple and easy to understand, in some drawings, only one of the parts with the same structure or function is shown, or only one of them is marked. In this paper, "one" not only means "only one", but also means "more than one".

[0064] It should be further understood that the term "and / or" used in the specification and the appended claims of the present application means any combination of one or more of the associated listed terms and all possible combinations, and includes these combinations.

[0065] In this article, it is necessary to point out that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to specific circumstances.

[0066] In addition, in the description of the present application, the terms "first", "second" and the like are only used for distinguishing description, and cannot be understood as indicating or implying relative importance.

[0067] In the traditional steam generation system, the heat pump device 20 is mainly used for the preliminary heating of low-temperature water, and the energy storage device undertakes the main heat demand from preliminary heating to the target steam temperature. However, this design has significant deficiencies in energy distribution and heating efficiency. On the one hand, the high energy efficiency characteristics of the heat pump device 20 are not fully utilized. The heat pump device 20 shows higher coefficient of performance (COP) in low-temperature rise working condition, but due to the failure to optimize its working range, part of the high-efficiency heat is not effectively utilized, resulting in energy waste in the preliminary heating stage. On the other hand, the energy storage device needs to undertake the heating task of a large temperature rise, and its heat storage medium needs to handle a large temperature difference, which not only increases the thermal stress of the medium, but also increases the energy loss and shortens the service life of the energy storage module 50.

[0068] The existence of the above problems may be due to the insufficient cooperation research of the heat pump device 20 and the energy storage system. In the traditional system design, the heat pump device 20 and the energy storage device are often regarded as independent subsystems, lacking the design concept of collaborative optimization. This leads to the mismatch between the high-temperature water temperature output by the heat pump device 20 and the heating starting temperature of the energy storage device, so that the efficient coupling utilization of energy cannot be realized.

[0069] Further analysis found that the traditional design failed to fully utilize the valley electricity operation advantage of the heat pump device 20. The heat pump device 20 can significantly reduce the heating cost by running in the valley electricity period of low electricity price, but due to the lack of targeted strategies, the running efficiency of the heat pump device 20 in the valley electricity period is limited, which cannot meet the demand of efficiently preparing high-temperature water close to saturated temperature. In addition, due to the mismatch between the output temperature of the heat pump device 20 and the heating demand of the energy storage device, the overall energy efficiency of the system does not reach the optimal state, thereby increasing the operating cost and carbon emissions.

[0070] In summary, full use of the high energy efficiency characteristics of the heat pump device 20 realizes seamless coupling of its heating range and energy storage range, which is an important direction to improve the energy efficiency and economy of the system. The utility model discloses the collaborative optimization design of heat pump device 20 and energy storage device realizes efficient high-temperature water preparation in valley electricity period, and further heating is realized through the energy storage device, realizes the hierarchical utilization of energy, and solves the above-mentioned problems existing in the traditional system.

[0071] As Figure 1 , the energy storage coupled heat pump steam generation system of an embodiment of the utility model is shown, comprising a heat pump device 20, a water storage device 30, an energy storage device and a plurality of pipelines and control components connected thereto. The heat pump device 20 and the energy storage device realize efficient energy transfer and hierarchical utilization through the water storage device 30. Specifically, the heat pump device 20 is used to heat water to a first temperature in the valley electricity period, and the first temperature is the high-temperature water temperature close to the saturation temperature, and the high-temperature water is delivered to the water storage device 30; the water storage device 30 is responsible for heat preservation and storage of the high-temperature water heated to the first temperature by the heat pump device 20; the energy storage device further heats the high-temperature water to a second temperature to generate first water vapor to be delivered to the steam use system.

[0072] In specific implementation, referring to Figure 2 and Figure 3 , the energy storage device comprises at least one energy storage module 50, and each energy storage module 50 adopts a double-layer structure of an outer cylinder and an inner cylinder. The outer cylinder and the inner cylinder are filled with a heat storage medium (such as molten salt), and a first heat exchange pipeline 52 and a second heat exchange pipeline 53 are respectively arranged on the inner wall of the outer cylinder and the outer wall of the inner cylinder. The first heat exchange pipeline 52 is used for heat transfer of high-temperature water, and can further heat the water to the first water vapor of the second temperature; the second heat exchange pipeline 53 is used for realizing deep heat release of the heat storage medium, and is preheated by the heat pump device 20 in the valley electricity period. Preferably, the first heat exchange pipeline 52 is a heat exchange coil welded to the inner wall of the outer cylinder, and the second heat exchange pipeline 53 is a heat exchange coil welded to the outer wall of the inner cylinder, and the heat exchange coil can be a vertical serpentine coil. The above design not only optimizes the heat utilization efficiency of the heat storage medium, but also improves the overall energy efficiency of the energy storage device through the double-layer heat exchange structure.

[0073] Further, to enhance the applicability and flexibility of the energy storage device, multiple inner cylinders can be provided in the embodiment and adopt different structural configuration forms. For example, multiple inner cylinders can be arranged in concentric circles by being stacked on each other, or multiple single inner cylinders can be independently provided. The inner structure of the inner cylinder supports multiple implementation modes: the inner cylinder can be filled with molten salt to increase the energy storage capacity, or can be filled with solid heat exchange material (such as graphite block) to enhance the heat conduction performance, or can even be designed as a hollow structure for direct heat exchange under specific conditions. In addition, the types of molten salt between the inner cylinder and the outer cylinder can be the same, or different types of molten salt can be selected according to specific working conditions, for example, the inner cylinder is filled with low-melting-point molten salt, and the outer cylinder is filled with high-melting-point molten salt, to achieve a wider temperature operating range.

[0074] To adapt to the needs of large-scale production and subsequent expansion, the molten salt energy storage module in the embodiment adopts a modular design, and the energy storage capacity of a single module is Q0, and the upper limit of the heat release power is P0. The modular design allows the energy storage device to flexibly adjust the number of modules according to the specific steam demand, and supports parallel or series operation modes to meet different working condition requirements.

[0075] In a specific design, to ensure that the maintenance of a single module does not affect the overall heat supply, the number of modules needs to meet the following conditions: the daily steam demand of the user side is Q, and the hourly steam power is P. If then n = 2, that is, at least 2 modules are needed; if n ≥ 2, then At the same time, the energy storage capacity of a single module is calculated as Q0 = 90% × Q / n, to ensure that the energy storage module 50 has a certain energy storage margin while meeting the steam demand. In a more specific embodiment, the selected power of the heat pump device 20 is 10% of the total steam demand of the user side, that is, 10%*Q / t, where t is the operating hours of the heat pump device 20. By reasonable selection, the heat pump device 20 can efficiently operate in the valley electricity period, and prepare high-temperature water close to the saturation temperature for the energy storage module 50, effectively reducing the overall energy consumption of the system.

[0076] In a high steam demand scenario, the energy storage module 50 can switch to a parallel operation mode, and each module independently releases heat to form multiple steam generation paths to meet the rapid steam demand and significantly improve the steam response speed; in a low steam demand scenario, the energy storage module 50 switches to a series operation mode, and the low-temperature molten salt that has released part of the heat is used to preheat other modules to maximize the use of the heat storage medium, thereby optimizing the energy efficiency. In addition, to enhance the operation flexibility, the preheating flow rate between the modules can be dynamically adjusted in the series mode to optimize the heat distribution.

[0077] The embodiment specifically adopts three parallel molten salt energy storage modules, with a working temperature range of 180-400°C (fifth temperature to fourth temperature), suitable for large-scale industrial steam demand. However, the configuration of the energy storage module 50 is not limited thereto. In other embodiments, solid energy storage, phase change energy storage or thermochemical energy storage modules can be used according to demand. The different energy storage modules 50 can be the same or different, and the working temperature can be set uniformly or in segments. For example, in a system requiring multi-stage heat supply, molten salt energy storage modules (high-temperature section), phase change energy storage modules (medium-temperature section) and solid energy storage modules (low-temperature section) can be combined to meet the complex process requirements.

[0078] Preferably, the molten salt can be selected as a low-melting-point mixed molten salt (melting point below 100°C) to reduce the system startup temperature and enhance the deep heat release capacity of the energy storage module 50. In addition, the heat storage medium can also be selected as a high-thermal-conductivity solid material (such as graphite or aluminum), to improve the heat transfer efficiency and adapt to the high heat flux density demand under special operating conditions. For low-temperature section applications, phase change energy storage materials (such as sodium hydroxide) can provide higher energy storage density, while reducing the material volume and improving the compactness of the system.

[0079] In a specific embodiment, the energy storage module 50 further comprises an electric heater 51, configured to be inserted straight from the top of the energy storage module 50, with a distance of 100-200 mm from the bottom of the module, to balance the heating effect and the temperature control requirements of the module base. The number of electric heaters 51 is generally 5-6, of which one is a full-section heater for melting solid molten salt, with its immersed part being full-section heating, and the power being adjusted by a thyristor, and the remaining electric heaters 51 are 2 / 3-section heating, heating only the lower 2 / 3 part of the molten salt, and the power is not adjustable. By reasonably configuring the heating section, combined with the temperature stratification characteristics of the upper hot and lower cold in the module, the phenomenon of overheating of the upper molten salt and insufficient heating of the lower molten salt is effectively avoided, improving the uniformity of molten salt heating and the stability of system operation.

[0080] Further optimization, the heat pump device 20 adopts a transcritical carbon dioxide cycle design, realizing heat conversion from a low-temperature heat source to a high-temperature heat carrier through an efficient transcritical cycle. This design enables the outlet temperature range of the heat pump to be accurately controlled within a range close to the saturation temperature (such as 90-98°C), providing the energy storage device with high-temperature water at the optimal working temperature, significantly improving the heating efficiency of the energy storage device. The selection of the heat pump device 20 can be air source heat pump, water source heat pump, ground source heat pump or waste heat source heat pump according to different heat source conditions, and the specific configuration can be optimized based on environmental conditions and steam demand. Further, the heat pump device 20 can adopt a cascade heating design to meet higher temperature requirements.

[0081] Further optimization, water storage device 30 is connected between heat pump device 20 and energy storage device, with sealing and pressurization function, for maintaining the liquid state of high temperature water and avoiding phase change heat loss. For further optimization of system performance, when the heating capacity of heat pump device 20 can reach 150 DEG C, the water storage device 30 can adopt the design of pressurized heat preservation water tank, and the internal pressure is kept at about 0.6MPa, so as to ensure that the saturation temperature of water reaches about 158 DEG C. Under this pressure condition, when the water is heated to the first temperature (150 DEG C) by the heat pump device 20, the water still keeps liquid state and is slightly lower than the saturation temperature, and the design makes the heating capacity and high energy efficiency characteristics of the heat pump fully play.

[0082] Further, when the heat pump device 20 with higher heating capacity (such as heating to 180 DEG C or higher) is used, the internal pressure of the water storage device 30 can be correspondingly increased to match the saturation temperature of the water. For example, when the target heating temperature is 180 DEG C, the internal pressure of the water storage device 30 can be increased to about 1.0MPa, so that the saturation temperature of the water exceeds the target temperature, and the stability of the liquid state is ensured. By dynamically adjusting the pressure setting of the water storage device 30, the heating capacity and working condition requirements of different types of heat pumps can be flexibly adapted, and the applicability and energy efficiency of the system are further improved.

[0083] The high-pressure heat preservation design of the water storage device 30 also has the following advantages: on the one hand, by maintaining a higher internal pressure, the heat loss of high-temperature water is effectively reduced, and the efficient transmission to the energy storage device is ensured; on the other hand, the liquid high-temperature water under high-pressure condition can significantly reduce the time delay of steam supply, and improve the response speed of the whole system. In addition, the water storage device 30 combines with high-efficiency heat preservation material, further reduces the heat energy loss in the long-term storage process, and significantly improves the overall operation efficiency of the system.

[0084] Therefore, by combining the heat pump heating capacity and the design of pressurized heat preservation water tank, the full use of the high energy efficiency heating characteristics of the heat pump device 20 is realized, and the dynamic pressure adjustment of the water storage device 30 adapts to the diversified working condition requirements, and provides reliable guarantee for efficient and stable steam heating.

[0085] In addition, a specific example is given in the utility model to analyze the change of overall energy efficiency of the system:

[0086] Assuming that the system heat source temperature is 10 DEG C, the output steam temperature is 180 DEG C, and the heat preservation water tank works under different temperature conditions, the change of overall COP of the system is analyzed. When the temperature of the heat preservation water tank is 95 DEG C, the heat pump heats the water from 10 DEG C to 95 DEG C, and the required heat is Q 热泵 = 1 x 4.2 x (95-10) = 357kJ / kg. Assuming that the COP of the heat pump is 3.0, the input electric energy of the heat pump is W 热泵 = Q 热泵÷ COP = 357 ÷ 3.0 = 119 kJ / kg. The energy storage device needs to heat the water from 95°C to 180°C, the required heat is Q 储能 = 1 x 4.2 x (180 - 95) = 357 kJ / kg. Assuming the efficiency of the energy storage device is 90%, the energy storage loss is L 储能 = Q 储能 x 0.1 = 35.7 kJ / kg. The total input electrical energy of the system is W 总＝ W 热泵 + L 储能 = 119 + 35.7 = 154.7 kJ / kg, the total output heat is Q 总输出 = Q 热泵 + Q 储能 = 357 + 357 = 714 kJ / kg. At this time, the total COP of the system is COP 系统 = Q 总输出 ÷ W 总 = 714 ÷ 154.7 ≈ 0.97.

[0087] When the temperature of the insulated water tank is increased to 150°C, the heat pump needs to heat the water from 10°C to 150°C, the required heat is Q 热泵 = 1 x 4.2 x (150 - 10) = 588 kJ / kg. Assuming the heat pump COP drops to 2.2, the input electrical energy of the heat pump is W 热泵 = Q 热泵 ÷ COP = 588 ÷ 2.2 = 267.3 kJ / kg. The energy storage device only needs to heat the water from 150°C to 180°C, the required heat is Q 储能 = 1 x 4.2 x (180 - 150) = 126 kJ / kg, the energy storage loss is L 储能 = Q 储能 x 0.1 = 12.6 kJ / kg. The total input electrical energy of the system is W 总 = W 热泵 + L 储能 = 267.3 + 12.6 = 279.9 kJ / kg, the total output heat is Q 总输出 = Q 热泵 + Q 储能 = 588 + 126 = 714 kJ / kg. At this time, the total COP of the system is COP 系统 = Q 总输出 ÷ W 总 = 714 ÷ 279.9 ≈ 1.02.

[0088] From the results, although the heat pump COP decreases from 3.0 to 2.2 due to the outlet temperature rising, the total COP of the system increases from 0.97 to 1.02 because the energy storage device burden is significantly reduced, which shows that increasing the temperature of the insulation water tank can optimize the overall efficiency of the system within a certain range. In practical applications, the working temperature of the insulation water tank needs to be further simulated and optimized according to the specific system parameters to achieve the best performance.

[0089] In a further optimized embodiment, the energy storage coupled heat pump steam generation system includes various pipelines and control components for efficient heat transfer and flexible control of system operation. The pipeline and control components mainly include a first feedwater pipeline, a recirculation branch 41, a desuperheating water branch 42, a second feedwater pipeline, a preheating loop, a branch valve group, and cooperating electric valves, a main pipe valve group, and a desuperheater 70, etc.

[0090] The first feedwater pipeline connects the water storage device 30 and the energy storage module 50, and is used to transport high-temperature water to the heat exchange pipeline of the energy storage module 50. Two sets of feedwater pumps are arranged in the first feedwater pipeline, one for use and one for backup, to ensure the continuity and reliability of water supply through an automatic switching mechanism. The feedwater pump group is connected to the main pipe valve group, which is used to adjust the flow of high-temperature water delivered to the energy storage module 50, ensuring that different steam load demands are met. If the system includes multiple energy storage modules 50, the main pipe valve group is connected to each module through a branch pipe valve group, which is used to accurately adjust the flow of high-temperature water entering each energy storage module 50, ensuring uniform water inflow to each module during operation. In addition, an electric valve is arranged between each branch pipe valve group and the energy storage module 50, which is used to shut off when a specific module stops running or is under maintenance.

[0091] A recirculation branch 41 is drawn from the main pipe valve group and the energy storage module 50, and is connected to the water storage device 30, which is used to realize the backflow of high-temperature water during system operation. The recirculation branch 41 can be opened through bypass adjustment when the system pressure rises rapidly, returning part of the feedwater to the water storage device 30, thereby reducing the water inflow to the energy storage module 50, controlling the pressure fluctuation of the system, and avoiding overpressure operation of the system.

[0092] A desuperheating water branch 42 is drawn from between the feedwater pump group and the main pipe valve group in the first feedwater pipeline, and is connected to the desuperheater 70. The desuperheating water transported through this branch mixes with the high-temperature steam in the desuperheater 70 and is then output to the steam main pipe on the user side, adjusting the steam temperature to the third temperature required by the user. The connection mode of the desuperheating water branch 42 ensures that the inlet pressure of the desuperheating water pipeline is not affected by the action of the main pipe valve, ensuring that the steam temperature on the user side does not exceed the limit under any operating condition.

[0093] The second water supply pipeline connects the heat pump device 20 and the energy storage module 50, and is used for directly conveying the high-temperature water generated by the heat pump device 20 to the heat exchange pipeline of the energy storage module 50. The heat pump device 20 directly supplies water to the energy storage device, or simultaneously supplies water to the energy storage device with the water storage device 30, which is used for directly supplying water from the heat pump device 20 to the energy storage device when the steam demand is small, such as when the water supply flow of the heat pump device 20 meets the steam flow demand, or for emergency.

[0094] The desuperheater 70 is connected to the pressure stabilizing device through the steam input port, the pressure stabilizing device is connected to the energy storage module 50, and the energy storage module 50 supplies the first water vapor to the pressure stabilizing device, and the desuperheating water branch 42 is connected to the desuperheating water input port of the desuperheater 70. The pressure stabilizing device is preferably a steam cylinder 60, and the steam output of the energy storage module 50 is collected through the steam cylinder 60 and then combined into one path before entering the desuperheater 70, fully mixed with the desuperheating water, and outputting steam at a temperature meeting the user's demand. The design of the desuperheater 70 can flexibly adjust the steam temperature to adapt to different user-side process requirements, ensuring the accuracy and stability of steam supply.

[0095] The preheating circuit is used for preheating the heat storage medium in the energy storage module 50 by the heat pump device 20 during the valley electricity period. The preheating circuit includes a third water supply pipeline and a preheating return water pipeline, which are connected between the heat pump device 20 and the energy storage module 50 respectively, forming a closed loop to realize efficient heating of the heat storage medium below the first temperature. Specifically, the third water supply pipeline is connected to the outlet end of the heat pump device 20, and is used for conveying the high-temperature water heated by the heat pump to the heat exchange pipeline inside the energy storage module 50 to heat the heat storage medium by using the sensible heat of the high-temperature water; the preheating return water pipeline is connected to the outlet end of the heat exchange pipeline inside the energy storage module 50, and is used for returning the low-temperature water after heat exchange to the inlet end of the heat pump device 20 for cyclic heating. Through the preheating circuit, the heat pump can realize step-by-step heating of the low-temperature heat storage medium, so that it gradually approaches the first temperature, thereby providing a more efficient thermal state for the subsequent high-temperature water preparation and steam generation process.

[0096] Further, the heat exchange pipeline of the energy storage module 50 is designed to be compatible with the operation mode of the preheating circuit. The third feedwater pipeline and the preheating return water pipeline in the preheating circuit are both connected to the heat exchange pipeline inlet and outlet of the energy storage module 50, so that the third feedwater pipeline, the heat exchange pipeline and the preheating return water pipeline together constitute an efficient preheating circulation circuit. In addition, in order to further improve the preheating efficiency of the energy storage module 50, an independent preheating pipeline can be additionally provided inside the energy storage module 50. The third feedwater pipeline and the preheating return water pipeline are respectively connected to the independent preheating pipeline, forming a more specialized preheating circuit for specifically processing the low-temperature preheating demand of the heat storage medium under specific working conditions. Specifically, the preheating circuit communicates with the first heat exchange pipeline 52 and / or the second heat exchange pipeline 53, and preferably the second heat exchange pipeline 53. The preheating pipeline is provided on the inner cylinder wall surface of the energy storage module 50, and is preferably welded to the outer wall surface of the inner cylinder.

[0097] In this embodiment, the preheating circuit not only preheats the heat storage medium by using the heat pump during the valley electricity period to improve the standby efficiency of the energy storage module 50, but also significantly shortens the start-up time of the system and reduces the operating load of the traditional high-energy-consumption heater during the start-up phase.

[0098] In a further optimized embodiment, the energy storage coupled heat pump steam generation system includes a deionized water supply device, a blowdown pipeline 43 and a multi-stage pressure protection and pressure relief assembly to ensure the stability and safety of the system operation.

[0099] The deionized water supply device includes a raw water tank 11, a water treatment device 12, a pure water tank 13 and a deionized water supply pipeline connected in sequence. In order to improve the reliability of the system operation, a tap water pipe bypass is provided before the inlet of the pure water tank 13. When the water treatment device 12 cannot work normally, tap water can directly enter the pure water tank 13 through the bypass as a temporary water source. Specifically, raw water is connected from the tap water pipeline in the factory, first enters the raw water tank 11, and the raw water tank 11 serves as a buffer device and can store about 3-6 hours of water consumption to cope with instantaneous water demand fluctuations. The raw water is transported to the water treatment device 12 by a raw water pump for softening and desalination. The treated desalinated water quality should meet the water quality standard for tubular boilers in GB / T1576 Industrial Boiler Water Quality. Then temporarily stored in the pure water tank 13. The pure water tank 13 has a storage capacity of about 3 hours of water consumption to ensure the continuous water supply capacity of the system during maintenance or shutdown of the water treatment device 12.

[0100] Two groups of desalinated water pumps are provided on the deionized water supply pipeline, one for use and one for standby, to ensure the continuous supply of desalinated water through the automatic switching function. The deionized water passing through the desalinated water pump enters the heat pump device 20 through the adjusting valve.

[0101] In other embodiments, the deionized water supply device can also supply water to the energy storage module 50 and the desuperheating water input port according to the demand.

[0102] The drain pipeline 43 is connected to the water inlet of the energy storage module 50, and is used to drain the residual working medium in the energy storage module 50 in the case of system shutdown or emergency. The drain pipeline 43 is provided with a drain valve near the water inlet, and can include an electrically controlled valve and a manually controlled valve. In normal operation, the drain valve is kept closed, and in the case of shutdown or system overpressure, the drain valve is opened, and the residual water working medium is pressed into the drain well by the residual pressure in the energy storage module 50, so as to ensure that there is no residual working medium in the system, thereby improving the operation safety.

[0103] The steam pipeline 44 connects the energy storage module 50 and the pressure stabilizing device, and is used to transport steam. A mechanical safety valve 81 is installed on the steam pipeline 44, and when the steam pressure exceeds a set safety threshold, the mechanical safety valve 81 automatically jumps to release excess steam, preventing system overpressure. After the steam is output, it is collected into the steam cylinder 60, and is connected to the desuperheater 70 through a steam main pipeline. An overpressure relief valve 82 is arranged on the steam main pipeline, and when the steam pressure exceeds a second warning value, the overpressure relief valve 82 is automatically opened to discharge excess steam to a safe area.

[0104] In order to ensure the safety of the system under different operating conditions, the system is provided with four pressure protection measures: first warning: when the steam pressure exceeds the set threshold, the feedwater main pipeline regulating valve automatically adjusts the flow according to the pressure signal, controls the amount of high-temperature water entering the energy storage module 50, and balances the system pressure; second warning: when the pressure continues to rise, the overpressure relief valve 82 is opened to discharge excess steam to a safe area; third warning: if the pressure further rises to an emergency shutdown threshold, the system enters an emergency shutdown state, and the drain valve is opened to quickly discharge all working medium to the drain well to quickly reduce the system pressure; fourth warning: in the case of extreme overpressure, the mechanical safety valve 81 automatically jumps to release steam, ensuring the safe operation of the system and equipment. Through the above multi-stage pressure protection design and the rapid response capability of the drain pipeline 43, the system can quickly take measures in the case of sudden pressure fluctuation, significantly reducing the risk of overpressure and improving the safety and stability of operation.

[0105] In further embodiments, the energy storage module 50 is configured with an auxiliary heater and an emergency heating module to enhance the operation flexibility and reliability of the system. The auxiliary heater directly heats the fluid in the heat exchange pipeline, and is mainly used for rapid heating in the starting stage or heat supplement in the case of low load operation. The emergency heating module includes an emergency heating pipeline, which can be connected in series or parallel with the heat exchange pipeline of the energy storage module 50, and provides supplemental heating when the heat dissipation power of the energy storage module 50 is insufficient or part of the module is under maintenance. Through the above configuration, the system can realize continuous and stable heating in the starting, peak load or special working conditions, significantly improving the operation efficiency and safety.

[0106] In order to have a clearer understanding of the technical scheme and technical effects of the energy storage coupled heat pump steam generation system of the utility model and put forward a steam generation method suitable for the above-mentioned energy storage coupled heat pump steam generation system, through the hierarchical cooperation of the heat pump device 20, the water storage device 30 and the energy storage module 50, the efficient heating capacity of the heat pump device 20 is utilized to heat the water to high-temperature water at the first temperature during the valley electricity period, and the energy storage module 50 is further utilized to heat the high-temperature water to first water vapor at the second temperature, thereby meeting the steam demand of the user side. The method realizes efficient utilization of energy and optimizes the operation economy and flexibility of the system. It should be pointed out that each embodiment of the following energy storage coupled heat pump steam generation method is suitable for operation in the above-mentioned system structure, but is not limited to the above-mentioned system structure.

[0107] Specifically, as Figures 4-7 , the energy storage coupled heat pump steam generation method comprises the following steps:

[0108] S1, the desalted water is heated to high-temperature water at the first temperature (close to the saturation temperature) by the heat pump device 20, and is stored in the water storage device 30.

[0109] S2, during the steam supply period, the high-temperature water in the water storage device 30 is transported to the energy storage module 50 through the first feedwater pipeline, is further heated to the second temperature by the molten salt storage tank, and first water vapor is generated.

[0110] Further, the first temperature is set according to the heating capacity of the heat pump device 20, when the heat pump device 20 has a higher heating capacity (for example, a transcritical carbon dioxide heat pump), the water can be heated to higher than 100 DEG C, at this time, the pressurized heat preservation water tank is adopted in the embodiment, and the liquid state of the high-temperature water is maintained by setting a specific pressure value. At the same time, the first feedwater pipeline is also matched with pressure regulation, and is used as a pressure pipeline to transport the high-temperature water between the heat pump device 20 and the water storage device 30.

[0111] Preferably, the first temperature is lower than the corresponding saturation temperature first temperature difference, and the first temperature difference is in the range of 2 to 10 DEG C, preferably 4 to 6 DEG C. The vaporization phenomenon that may occur when the liquid high-temperature water approaches or exceeds the saturation temperature during the heating process can be effectively avoided, and the stable liquid state of the high-temperature water in the water storage device 30 and the transport pipeline is ensured. Not only the heating efficiency of the heat pump device 20 is improved, the energy consumption is reduced, but also the heat loss and system fluctuation caused by phase change are reduced.

[0112] Further, the following steps are included:

[0113] S3, the first water vapor at the second temperature is mixed with the high-temperature water at the first temperature by the desuperheater 70 to generate second water vapor at the third temperature, and the third temperature is between the first temperature and the second temperature (such as 180 to 250 DEG C), which is used to meet the demand of the steam use system for steam at different temperatures.

[0114] The embodiment realizes the hierarchical efficient use of heat by the organic combination of the high-efficiency heating characteristics of the heat pump device 20 and the high-density energy storage characteristics of the energy storage device. The method not only significantly improves the energy efficiency of the system, reduces the energy cost, but also optimizes the operation load of the energy storage module 50, reduces the thermal stress of the molten salt, thereby prolongs the service life of the equipment, improves the safety and stability of the system operation, and meets the economy and flexibility of the industrial steam demand.

[0115] In another embodiment (operation regulation of the energy storage device and the heat pump device 20), as Figures 5-7 , comprising the following specific steps:

[0116] S10, using the historical data of the steam use system and the real-time working condition, predicting the first steam demand amount of the steam supply period, and determining the corresponding first water steam enthalpy increment. According to the prediction result, the operation of the energy storage device and the heat pump device 20 is provided with regulation basis.

[0117] S20, in the valley electricity period, the energy storage device is used to store heat in the form of electric heating, and the heat storage medium (such as molten salt) is heated to a set fourth temperature (such as 400℃). Preferably, the heating temperature of the heat storage medium is dynamically adjusted according to the demand amount, so as to ensure the economy and effectiveness of heat storage.

[0118] S30, control the heat pump device 20 to run at least part of the time in the valley electricity period to prepare the required high-temperature water, and heat the desalted water to a first temperature close to the saturation temperature (such as 90℃).

[0119] S40, the sum of the second enthalpy increment provided by the energy storage device and the first enthalpy increment provided by the heat pump device 20 is matched with the first water steam enthalpy increment corresponding to the first steam demand amount.

[0120] Further, the running proportion of the heat pump device 20 in the valley electricity period is optimized, and the specific process is:

[0121] S31, obtain the power supply capacity available for steam generation in the valley electricity period, and determine the second electricity consumption required by the energy storage device in the valley electricity period;

[0122] S32, calculate the first difference value of the valley electricity supply capacity and the second electricity consumption of the energy storage device:

[0123] If the first difference value is sufficient to complete the preparation of the total amount of high-temperature water, the heat pump device 20 completes the preparation of all high-temperature water in the valley electricity period;

[0124] If the first difference value is insufficient, the heat pump device 20 uses the first difference value to partially prepare the high-temperature water in the valley electricity period, and the remaining part is supplemented and completed in the flat electricity period.

[0125] S33, calculate the first electricity consumption required for the heat pump device 20 to prepare all high-temperature water meeting the steam supply demand during the valley electricity period. The first electricity consumption is a function of the heat pump device 20 running time, power and water heating demand, ensuring that the prepared high-temperature water can meet the demand of the first temperature.

[0126] S34, after deducting the second electricity consumption of the energy storage device from the available capacity during the valley electricity period, calculate the remaining electricity (first difference electricity). Then calculate the difference between the first difference electricity and the first electricity consumption to obtain the second difference electricity. The second difference electricity is the remaining electricity of the system.

[0127] S35, real-time monitoring of the first difference electricity and the heating capacity of the heat pump device 20, when the first difference electricity and the heating capacity of the heat pump device 20 exceed the demand of the high-temperature water of the first temperature, the second difference electricity is used to provide preheating heat for the energy storage device through the heat pump device 20.

[0128] Further, the embodiment further comprises the following steps:

[0129] S51, during the steam supply period, the high-enthalpy heat provided by the energy storage device is used to further heat the high-temperature water to generate superheated steam of the second temperature for use on the user side.

[0130] S52, during the steam demand period, when the energy storage device heat release power is insufficient (for example, at the end of the steam supply period), the high-temperature water in the heat exchange pipeline is quickly supplemented by the configured auxiliary heater or auxiliary heating module, ensuring the continuity and stability of the steam supply.

[0131] S53, during the steam demand period, after the molten salt storage tank is heated to the fifth temperature (such as 200°C), if there is still steam demand, the high-temperature water is dynamically supplemented to the energy storage device through the heat pump device 20, and the electric heating function of the energy storage module 50 is combined to further improve the heat output; or directly heated to the target temperature through the heat pump device 20 to ensure the stability and continuity of the steam supply.

[0132] The embodiment precisely matches the steam supply demand through the coordinated operation of the energy storage device and the heat pump device 20, combined with historical data and real-time load prediction, significantly improves the operation efficiency and flexibility of the system. During the valley electricity period, by optimizing the operation strategy of the energy storage device and the heat pump device 20, the low-cost electricity is fully utilized to heat the heat storage medium to a set high-temperature state, and the high-temperature water meeting the demand is prepared; during the steam supply period, the high-enthalpy heat provided by the energy storage device and the dynamic supplement of the heat pump device 20 ensure the continuity and stability of the steam supply.

[0133] The embodiment realizes the optimal allocation of electricity resources in the valley period. After the high-temperature water demand is met, the remaining electricity is used to preheat the energy storage device, reducing the heating burden of the steam supply period and further improving the system energy efficiency. At the same time, in the late steam supply period or peak load scenario, combined with the dynamic regulation of the auxiliary heating module and the heat pump device 20, the steam supply interruption caused by insufficient energy storage capacity is effectively avoided.

[0134] In another embodiment (determination of the energy storage capacity and heat release power of the energy storage device), the following specific steps are included:

[0135] S71, using historical data and real-time working conditions, predicting the first steam demand and the maximum steam demand rate in the steam supply period, corresponding to the total heat demand and the instantaneous heat supply capacity demand of the energy storage device. According to the steam demand characteristics, the enthalpy increment of the heat pump device 20 and the energy storage device to provide heat is calculated, and the first ratio of the two is determined. Preferably, the heat pump device 20 operates in the high-efficiency interval and mainly provides the first enthalpy increment for preparing high-temperature water; the energy storage device undertakes the high-enthalpy heat output as the second enthalpy increment to meet the high-temperature demand of steam generation.

[0136] According to the first ratio, the core parameters of the energy storage device are determined by the following steps:

[0137] S72, combined with the first steam demand and the first ratio, the energy storage capacity of the energy storage device is determined to ensure that it has sufficient heat reserve in the steam supply period. The preferred heat storage medium is molten salt, and the required mass and volume are calculated according to the working temperature range and specific heat capacity to ensure the economy and effectiveness of heat storage.

[0138] S73, according to the maximum steam demand rate and the first ratio, the heat release power of the energy storage device is designed to match the instantaneous steam load demand. By optimizing the heat exchange pipeline and branch valve group, the stability and uniformity of steam output are ensured.

[0139] The embodiment scientifically allocates the heat supply ratio of the heat pump device 20 and the energy storage device by predicting the steam demand and the maximum steam demand rate, optimizes the design of the energy storage capacity and the heat release power. The heat pump device 20 operates in the high-efficiency interval to prepare high-temperature water; the energy storage device provides high-enthalpy heat to meet the instantaneous load demand. This method realizes the hierarchical utilization and accurate matching of heat energy, reduces the operating cost, enhances the adaptability of the system to load fluctuations, and provides an efficient and stable steam heating scheme.

[0140] In yet another embodiment (deep heat release of the energy storage module 50), combined with the reference Figure 8 The embodiment describes a steam generation method based on deep heat release of the energy storage module 50, which realizes efficient utilization and deep heat release of the energy storage device through step-by-step heat release at multiple temperature stages and cooperative work of the heat pump device 20, specifically including the following steps:

[0141] S110, in the valley electricity period, the low-melting-point molten salt with an initial temperature of the eighth temperature (such as 40℃) is heated to a first temperature (such as 90℃) by the heat pump device 20. This process makes full use of low-cost valley electricity and the high-efficiency heating capacity of the heat pump to provide a basic heat reserve for subsequent electric heating of the molten salt.

[0142] S120, in the valley electricity period or the flat electricity low load period, the molten salt is heated from the first temperature to a fourth temperature (such as 400℃) by using the electric heater 51. This step lays the foundation for the high-enthalpy output of the energy storage module 50 and ensures sufficient heat reserve during the steam supply period.

[0143] S130, during the steam demand period, part of the molten salt of the energy storage module 50 is cooled from the fourth temperature to a fifth temperature (such as 200℃), and the second-temperature superheated steam (such as 180-370℃) is generated through the heat exchange pipeline. This stage adopts a parallel structure of multiple steam generation channels to meet the set steam demand flow.

[0144] S140, after the molten salt of part of the energy storage module 50 is cooled to the fifth temperature, the heat exchange pipeline is switched to a series mode to make these modules provide high-temperature water preheating for the energy storage module 50 still in a high-temperature state (the fourth temperature), while itself is further cooled to a sixth temperature (such as 120℃). This step optimizes the energy utilization efficiency of the high-temperature section of the molten salt and realizes the gradient cooperative cooling of the energy storage module 50.

[0145] S150, after the molten salt is cooled to the sixth temperature, the low-temperature water is heated to the first temperature (such as 90℃) and stored by adjusting the flow of the heat exchange pipeline. This stage adopts a low-flow operation mode to maximize heat recovery and further cool the molten salt to a seventh temperature (such as 100℃).

[0146] S160, the molten salt cooled to the seventh temperature is used to provide hot water for the water source heat pump, which further heats the hot water to the first temperature (such as 90℃) and stores it. This step cools the molten salt to the eighth temperature (such as 40℃) through the high-efficiency energy recovery of the heat pump device 20, and completes the deep cooling cycle of the energy storage module 50.

[0147] S170, after the molten salt of all energy storage modules 50 is cooled to the eighth temperature, step S110 is restarted to preheat the molten salt by the heat pump device 20 and enter the next cycle. At the same time, the cooling mode (parallel or series) and operating parameters of the energy storage module 50 are dynamically adjusted to adapt to the real-time steam demand of the user side.

[0148] Preferably, in step S140, the fifth temperature is higher than the second temperature by a second temperature difference, the second temperature difference ranges from 20 to 50 DEG C; the sixth temperature is higher than the first temperature by a third temperature difference, the third temperature difference ranges from 10 to 30 DEG C; the fourth temperature is higher than the sixth temperature by a fourth temperature difference, the fourth temperature difference is greater than the sum of the second temperature difference and the third temperature difference.

[0149] The embodiment realizes deep utilization of the energy storage module 50 through staged and step-by-step heat release. The switching of the parallel and series modes optimizes the cooperation efficiency of the energy storage module 50 in different temperature ranges, significantly improves the response speed and stability of steam supply, and at the same time, through preheating and waste heat recovery of the heat pump device 20, the low-cost valley electricity and low-temperature residual energy are fully utilized, the operation cost is reduced, the economic efficiency and environmental adaptability of the system are enhanced, and an efficient and stable solution for industrial steam under complex working conditions is provided.

[0150] The above-described embodiments only express several implementation manners of the utility model, the description is more specific and detailed, but it cannot be understood as the limitation of the utility model patent scope. It should be pointed out that for ordinary skilled persons in the art, without departing from the concept of the utility model, a number of modifications and improvements can be made, and the implementation steps can be combined, which all belong to the protection scope of the utility model; therefore, the protection scope of the utility model should be subject to the appended claims.

Claims

1. An energy storage coupled heat pump steam generation system, characterized by, Comprising: a heat pump device for heating water to a first temperature, the first temperature being a high temperature water temperature close to a saturation temperature; a thermal energy storage device comprising at least one thermal energy storage module filled with a thermal storage medium and equipped with a heat exchange pipeline for receiving the high temperature water at the first temperature and further heating to a second temperature through the thermal storage medium to generate a first water vapor.

2. The energy storage coupled heat pump steam generation system of claim 1, wherein, Further comprising: a water storage device fluidly connected to the heat pump device for heat-insulated storage of the high temperature water heated by the heat pump device to the first temperature; a first feedwater pipeline connecting the water storage device and the thermal energy storage module for conveying the high temperature water in the water storage device to the heat exchange pipeline; a pressure stabilizing device connected to the thermal energy storage module, the thermal energy storage module supplying the pressure stabilizing device with the first water vapor; a desuperheater comprising a steam input port connected to the pressure stabilizing device and a desuperheating water input port connected to the first feedwater pipeline, the desuperheater mixing the water vapor input from the steam input port and the desuperheating water input from the desuperheating water input port to output a second water vapor at a third temperature, the third temperature being lower than the second temperature.

3. The thermal energy storage coupled heat pump steam generation system according to claim 2, wherein the water storage device has a sealing and pressurizing function for maintaining the high temperature water above 100℃ in a liquid state.

4. The thermal energy storage coupled heat pump steam generation system according to claim 2, wherein the first feedwater pipeline comprises: a feedwater pump group and a main pipe regulating valve group connected in series to the thermal energy storage module; a desuperheating water branch leading from between the feedwater pump group and the main pipe regulating valve group and connected to the desuperheating water input port; a recirculation branch leading from between the main pipe regulating valve group and the thermal energy storage module and connected to the water storage device for realizing backflow of the high temperature water when the system is running.

5. The thermal energy storage coupled heat pump steam generation system according to claim 1, wherein the heat exchange pipelines of multiple thermal energy storage modules are configured to be connected in parallel between any two thermal energy storage modules to form multiple steam generation paths or connected in series to form a single steam generation path through switching operation.

6. The thermal energy storage coupled heat pump steam generation system according to claim 2, further comprising a deionized water supply device, the deionized water supply device is adapted to supply deionized water to the heat pump device, and / or the thermal energy storage module, and / or the desuperheating water input port. Further comprising a second feedwater pipeline, 7. The energy storage coupled heat pump steam generation system of claim 1 or 2, wherein, the second feedwater pipeline connecting the heat pump device and the thermal energy storage module for conveying the high temperature water generated by the heat pump device to the heat exchange pipeline.

8. The thermal energy storage coupled heat pump steam generation system according to claim 1, further comprising a preheating loop, the preheating loop comprising a third feedwater pipeline and a preheating return water pipeline, both of which are connected between the heat pump device and the thermal energy storage module to form a loop for heating the thermal storage medium below the first temperature by the heat pump device.

9. The thermal energy storage coupled heat pump steam generation system according to claim 8, wherein ​ The third feedwater pipeline and the preheating return water pipeline are both connected to the heat exchange pipeline, so that the third feedwater pipeline, the heat exchange pipeline and the preheating return water pipeline are adapted to constitute the preheating loop. And / or, the energy storage module is further provided with a preheating pipeline, the third feedwater pipeline and the preheating return water pipeline are both connected to the preheating pipeline, so that the third feedwater pipeline, the preheating pipeline and the preheating return water pipeline are adapted to constitute the preheating loop.

10. The energy storage coupled heat pump steam generation system according to claim 1, wherein The energy storage module comprises an outer cylinder and an inner cylinder, the inner cylinder is arranged in the outer cylinder, and the heat storage medium is arranged between the outer cylinder and the inner cylinder, and the heat exchange pipeline comprises a first heat exchange pipeline arranged in the outer cylinder and a second heat exchange pipeline arranged in the inner cylinder.

11. The energy storage coupled heat pump steam generation system according to claim 10, wherein The first heat exchange pipeline is a heat exchange coil welded to the inner wall of the outer cylinder, and the second heat exchange pipeline is a heat exchange coil welded to the outer wall of the inner cylinder.

12. The energy storage coupled heat pump steam generation system according to claim 10, wherein The second heat exchange pipeline is also used for preheating of the heat storage medium below the first temperature.

13. The energy storage coupled heat pump steam generation system according to claim 2, further comprising: a steam pipeline connected to the energy storage module and the pressure stabilizing device, and provided with a mechanical safety valve; a steam main pipe connected to the steam outlet of the desuperheater, and provided with an overpressure relief valve; a blowdown pipeline connected to the feedwater inlet of the energy storage module and communicated to a blowdown well, and provided with a blowdown valve.

14. The energy storage coupled heat pump steam generation system according to claim 4, wherein When a plurality of energy storage modules are included, a branch pipe valve group is further included, which is arranged between the main pipe valve group and each energy storage module, and is used for adjusting the flow of high-temperature water into each energy storage module.

15. The energy storage coupled heat pump steam generation system according to claim 1, wherein The heat storage medium comprises at least one of a molten salt heat storage medium, a solid heat storage medium, a thermochemical heat storage medium and a phase change heat storage medium; and / or The heat pump device comprises one or more of a waste heat source heat pump, an air source heat pump, a water source heat pump and a ground source heat pump, and adopts carbon dioxide as a circulating working medium and operates in a transcritical cycle state; and / or The heat pump device is configured to operate through cascade heating.

16. The energy storage coupled heat pump steam generation system according to claim 1, wherein The energy storage module further comprises an auxiliary heater adapted to heat the fluid in the heat exchange pipeline; or The steam generation system further comprises an emergency heating module, the emergency heating module comprises an emergency heating pipeline, and the emergency heating pipeline and the heat exchange pipeline are connected in series or in parallel, and are used for auxiliary heating when the heat release power of the energy storage module is insufficient. ​

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