Comprehensive energy system with coupled coal generator set, internal combustion engine and electrical methanol production facility

Abstract

The invention relates to the technical field of coal power units, in particular to a coal power unit, internal combustion engine and electric methanol production facility coupled comprehensive energy system, which comprises at least one coal power unit for providing basic load power output; the internal combustion engine coupling power generation system is used for responding to rapidly changing power demands; the electric methanol production device is coupled with the coal-fired power generation unit and the internal combustion engine power generation unit and meets power adjustment according to the adjustment requirement of electric power; the power system is used for receiving a power regulation demand signal of the power system. The system has the beneficial effects that the gas internal combustion engine capable of rapidly changing power is coupled with coal electricity and is combined with the methanol electricity production facility and the coal electricity platform, in the aspect of electricity, the rapid power changing characteristic is set through methanol electricity production, a coal electricity unit is assisted to improve the adjusting capacity, and therefore the flexibility of the power generation side is improved; therefore, the ever-increasing frequency modulation requirement of the power system is met.

Description

Technical Field

[0001] The present invention relates to the technical field of coal-fired power generation units, in particular to a comprehensive energy system coupled with coal-fired power generation units, internal combustion engines and electricity-to-methanol facilities. Background Art

[0002] As wind power and photovoltaic power, two renewable energy sources, play an increasingly important role in future power systems, the intermittent and volatile problems they bring are becoming increasingly prominent. This means that the power system must become more flexible in order to quickly and accurately respond to these unpredictable energy fluctuations to maintain the stable operation of the power grid. Although traditional coal-fired power generation units have a large power generation capacity and can theoretically meet large-scale power adjustment needs, due to their inherent technical limitations, such as fuel handling, combustion efficiency, and hysteresis in thermodynamic processes, these units are clumsy and not fast enough in frequency adjustment.

[0003] To overcome this challenge, an innovative solution has emerged: equipping coal-fired power plants with advanced electrochemical energy storage devices. This combination uses the fast response and flexible power regulation of electrochemical energy storage devices to compensate for the slow frequency regulation of traditional coal-fired units.

[0004] However, the functions of electrochemical energy storage devices are relatively simple, mainly focusing on frequency adjustment, and failing to play a greater role in other areas. Secondly, since frequency adjustment requires frequent charge and discharge cycles, this greatly shortens the service life of energy storage equipment. Furthermore, since the energy storage device itself has limitations on charge and discharge time and storage capacity, it is difficult for it to maintain unidirectional frequency adjustment for a long time, which in turn affects its long-term working effect.

[0005] One approach to improving the peak-shaving and frequency-regulating capabilities of coal-fired power units is to add electrode boilers to them, taking advantage of their fast regulation rate, high power density, low unit cost, and long service life. After being arranged in a coal-fired power plant, the overall peak-shaving and frequency-regulating performance of the power plant can be changed through flexible thermal-electric conversion. However, the existing patented technology does not solve the problem of loss of electrothermal conversion efficiency. The electricity used by the electrode boiler is generated by the high-temperature and high-pressure steam of the coal-fired power unit to drive the steam turbine. Due to condensation losses, the efficiency of generating electricity in this link is only about 45%. The electrode boiler then converts the electricity into hot water (or steam), which actually causes unnecessary losses. Although the overall peak-shaving and frequency-regulating performance of the coal-fired power unit has been improved, it has come at a high energy efficiency and economic cost. Summary of the invention

[0006] Some simplifications or omissions may be made in this section and the abstract and title of the present application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0007] The purpose of the present invention is to provide a comprehensive energy system coupling a coal-fired power unit, an internal combustion engine, and an electric methanol production facility.

[0008] Therefore, its purpose is to solve the problem that the electricity used by the electrode boiler is generated by the high-temperature and high-pressure steam of the coal-fired power unit to drive the steam turbine. Due to the condensation loss, the efficiency of generating electricity in this link is only about 45%. The electrode boiler then converts the electricity into hot water (or steam), which actually causes unnecessary losses.

[0009] In order to solve the above technical problems, the present invention provides the following technical solutions: an integrated energy system coupled with coal-fired power units, internal combustion engines, and methanol-to-electricity facilities, which includes at least one coal-fired power unit for providing basic load power output; an internal combustion engine coupled power generation system for responding to rapidly changing power demand; an methanol-to-electricity device coupled with the coal-fired power generation unit and the internal combustion engine power generation unit, and meeting power regulation according to the power regulation demand; a power system for receiving the power regulation demand signal of the power system and reasonably allocating the regulation tasks between the coal-fired power unit and the internal combustion engine coupled power generation system.

[0010] As a preferred solution of the integrated energy system of the present invention, which is a coupling of a coal-fired power unit, an internal combustion engine, and an electric methanol production facility, the electric methanol production device includes a CCUS unit for capturing carbon dioxide from flue gas emitted by a coal-fired unit or an internal combustion engine; a water electrolysis unit for producing hydrogen; and a synthesis reactor equipped with a catalyst for synthesizing the carbon dioxide from the CCUS unit and the hydrogen from the water electrolysis unit to produce methanol.

[0011] As a preferred solution of the integrated energy system of the present invention, which is a coupling of coal-fired power units, internal combustion engines, and electric methanol production facilities, the CCUS unit adopts at least one of chemical absorption, physical absorption, adsorption or membrane separation technology.

[0012] As a preferred solution of the integrated energy system of the present invention, which is a coupling of a coal-fired power unit, an internal combustion engine, and an electric methanol production facility, the water electrolysis unit includes at least one of an alkaline water electrolyzer, a proton exchange membrane (PEM) water electrolyzer, or a solid oxide water electrolyzer (SOEC).

[0013] As a preferred solution of the integrated energy system of the present invention, which is a coupling of a coal-fired power unit, an internal combustion engine, and an electric methanol production facility, the electric methanol production device includes heating carbon dioxide and hydrogen to at least 255°C to ensure that carbon dioxide and hydrogen undergo a methanol synthesis reaction under the action of a catalyst, and the reaction formula is as follows: CO2+3H2→CH3OH+H2O, and the reaction releases heat of about 57.78 kJ / mol.

[0014] As a preferred solution of the integrated energy system of the present invention, which is a coupling of a coal-fired power unit, an internal combustion engine, and an electric methanol production facility, the electric methanol production device also includes a storage container for storing the generated methanol fuel so that it can be used as a fuel for boiler stabilization or startup when needed by the coal-fired unit or the internal combustion engine.

[0015] As a preferred solution of the integrated energy system of the present invention, which is a coupling of a coal-fired power unit, an internal combustion engine, and an electric methanol production facility, the electric methanol production device also includes a feedback control system, which monitors the operating status of the coal-fired unit or the internal combustion engine, and adjusts the carbon dioxide capture rate of the CCUS unit and the methanol production of the synthesis reactor as needed.

[0016] As a preferred solution of the integrated energy system of the present invention, which is a coupling of coal-fired power units, internal combustion engines, and electric methanol production facilities, the waste heat recovery device collects the waste heat generated by the reaction during the purification reaction stage in the electric methanol production synthesis process.

[0017] As a preferred solution of the integrated energy system coupled with the coal-fired power unit, internal combustion engine and electric methanol production facilities of the present invention, the waste heat recovery device includes: at least one low-pressure heater, which is arranged before the material preheater, and is used to recover the heat in the electric methanol production process and to preheat the material entering the material preheater; a waste heat boiler, which is used to recover the heat generated by the exothermic reaction in the electric methanol production process and to generate low-pressure steam; a cooling device, which is arranged before the condenser, and is used to recover the unused heat in the electric methanol production process and convert this part of the heat into a usable energy form.

[0018] As a preferred solution of the integrated energy system of the present invention coupling coal-fired power units, internal combustion engines, and electric methanol production facilities, the cooling device adopts water cooling or air cooling technology, and transfers the cooled heat to the steam-water system of the coal-fired unit through a heat exchanger.

[0019] The beneficial effects of the present invention are as follows: the present invention couples a gas internal combustion engine capable of rapidly changing power with coal-fired power, and combines it with a methanol-to-electricity facility and a coal-fired power platform. In terms of electricity, the methanol-to-electricity facility is provided with a characteristic of rapidly changing power, which assists the coal-fired power unit in improving its regulation capability, so as to improve the flexibility of the power generation side, thereby meeting the growing frequency regulation demand of the power system;

[0020] In terms of heat, waste heat from the electrolysis methanol process is recovered through the low-pressure heater cascade of the coal-fired unit, thereby improving the overall energy efficiency of the system;

[0021] In terms of function, the produced methanol is used as the main fuel source for the startup and stable combustion of power plants, replacing the original diesel, without the need for external purchase. Methanol is a recognized clean fuel with green attributes. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0023] Figure 1 This is a system process flow chart of the coal-fired power unit coupled with the methanol production facility in the present invention.

[0024] Figure 2 It is a schematic diagram of the thermal coupling of the coal-electricity coupled internal combustion engine system in the present invention.

[0025] In the figure:

[0026] 100. Coal-fired power generation unit; 101. Internal combustion engine coupled power generation system; 200. Electricity-to-methanol device; 300. Power system; 400. Waste heat recovery device. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0028] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0029] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0030] Example 1

[0031] Reference Figure 1-2, which is the first embodiment of the present invention, provides an integrated energy system coupled with coal-fired power units, internal combustion engines, and methanol-to-electricity facilities, including at least one coal-fired power unit 100, used to provide basic load power output; an internal combustion engine coupled power generation system 101, used to respond to rapidly changing power demand; an methanol-to-electricity device 200, coupled with the coal-fired power generation unit and the internal combustion engine power generation unit, and according to the power regulation demand, to meet the power regulation demand; a power system 300, used to receive the power regulation demand signal of the power system 300, and reasonably allocate the regulation tasks between the coal-fired power unit 100 and the internal combustion engine coupled power generation system 101, so as to maximize flexibility and maximize the benefits of the auxiliary service market.

[0032] In this embodiment, the coal-fired power generation unit 100 is a form of traditional thermal power generation, and its main function is to provide a stable base load power output for the power system 300. In this system, the coal-fired power generation unit 100 is responsible for maintaining the basic power supply demand of the power grid and ensuring the stability of the power system 300.

[0033] The internal combustion engine coupled power generation system 101 is a device that combines an internal combustion engine with a generator to generate electricity.

[0034] Compared with the coal-fired power generation unit 100, the internal combustion engine coupled power generation system 101 has the characteristics of fast response speed and flexible startup, and is very suitable for coping with the rapidly changing power demand in the power grid. In the present system design, the internal combustion engine coupled power generation system 101 can quickly adjust its output power to compensate for the power fluctuation caused by the intermittent nature of renewable energy, and ensure the continuity and reliability of power supply.

[0035] The power-to-methanol device 200 is an innovative point of the present invention. It can not only use excess electricity to produce methanol, but also convert the stored methanol into electricity when needed, thereby playing the role of peak shaving and valley filling. This two-way energy conversion mechanism improves the energy utilization efficiency of the entire system, and also provides support for the flexibility of the power system 300. In addition, as a clean fuel, the production and use of methanol helps to reduce greenhouse gas emissions and meets the requirements of sustainable development.

[0036] The power system 300 is responsible for receiving power regulation demand signals from the power grid and reasonably allocating the regulation tasks between the coal-fired power generation unit 100 and the internal combustion engine coupled power generation system 101 according to these signals. This intelligent dispatching mechanism can effectively improve the flexibility of the system and also help to obtain higher economic benefits in the auxiliary service market.

[0037] Specifically, when the power system 300 receives a power regulation demand from the power grid, it will first evaluate the current power supply and demand situation. If the demand exceeds expectations, the internal combustion engine coupled power generation system 101 is started to quickly increase the power supply; if there is an oversupply, the excess energy can be converted into methanol and stored through the methanol-to-electricity device 200. After the power demand drops or the peak period has passed, the stored methanol can be converted back into electricity to supplement the power grid's needs. Such a dynamic regulation mechanism enables the system to maintain efficient operation under different power demand scenarios.

[0038] In summary, the comprehensive energy system proposed in this embodiment realizes the diversification and flexibility of energy supply by integrating multiple resources such as the coal-fired power generation unit 100, the internal combustion engine coupled power generation system 101 and the electric methanol device 200.

[0039] Example 2

[0040] Reference Figure 1-2 , which is the second embodiment of the present invention, is different from the previous embodiment in that the methanol-to-electricity device 200 includes a CCUS unit for capturing carbon dioxide from flue gas emitted by a coal-fired unit or an internal combustion engine; a water electrolysis unit for generating hydrogen; and a synthesis reactor equipped with a catalyst for synthesizing the carbon dioxide from the CCUS unit with the hydrogen from the water electrolysis unit to generate methanol. The CCUS unit adopts at least one of chemical absorption, physical absorption, adsorption or membrane separation technology. The water electrolysis unit includes at least one of an alkaline water electrolyzer, a proton exchange membrane (PEM) water electrolyzer or a solid oxide water electrolyzer (SOEC). The methanol-to-electricity device 200 includes heating carbon dioxide and hydrogen to at least 255°C to ensure that carbon dioxide and hydrogen undergo a methanol synthesis reaction under the action of a catalyst, and the reaction formula is as follows: CO2+3H2→CH3OH+H2O, and the reaction exothermicity is about 57.78 kJ / mol.

[0041] In this embodiment, the CCUS unit is mainly used to capture carbon dioxide from flue gas emitted from coal-fired power plants, natural gas power plants or other industrial processes.

[0042] For example, chemical absorption: using chemical reagents such as amine-based solutions to absorb carbon dioxide from flue gas. This method is simple to operate, but requires high energy consumption for absorbent regeneration.

[0043] Adsorption: Using solid adsorbents such as activated carbon or metal organic frameworks (MOFs) to capture carbon dioxide. The advantage of this method is that the adsorbent can be recycled.

[0044] Membrane separation: Separating carbon dioxide through polymer membranes or inorganic membranes. This technology has the characteristics of low energy consumption and small footprint.

[0045] Water electrolysis units are used to produce hydrogen, one of the essential raw materials in the methanol synthesis process. The unit is usually powered by an electrical source and splits water into oxygen and hydrogen.

[0046] For example, proton exchange membrane (PEM) water electrolyzers: they are able to operate at higher pressures and temperatures, have high efficiency, and are suitable for rapid response to changes in electricity supply.

[0047] Solid oxide water electrolyzer (SOEC): can operate at high temperature conditions, is more efficient, and can also use a variety of energy forms.

[0048] The synthesis reactor is where the captured CO2 and produced hydrogen are converted into methanol over a catalyst.

[0049] Commonly used catalysts include copper-based catalysts, zinc-based catalysts, and mixed metal catalysts.

[0050] Reaction equation: CO2+3H2→CH3OH+H2O. This reaction is an exothermic reaction, releasing approximately 57.78 kJ of energy per mole.

[0051] Specifically, the working principle of the whole system is based on the basic principles of electrochemistry and catalytic chemistry. First, the CCUS unit captures carbon dioxide from flue gas, and then the water electrolysis unit decomposes it to produce hydrogen through water electrolysis. Subsequently, in the synthesis reactor, carbon dioxide and hydrogen react chemically under high temperature and catalyst to produce methanol. This process not only realizes the reuse of carbon dioxide, but also demonstrates how to produce chemicals through renewable energy, thereby reducing dependence on fossil fuels and providing a possible direction for sustainable development.

[0052] In summary, the electric methanol unit 200 is an integrated system that combines advanced carbon capture technology, efficient water electrolysis technology, and a high-performance catalyst system, making the conversion of carbon dioxide to methanol possible.

[0053] The power-to-methanol device 200 also includes a storage container for storing the generated methanol fuel so that it can be used as a fuel for boiler stable combustion or startup when needed by the coal-fired unit or the internal combustion engine. The power-to-methanol device 200 also includes a feedback control system that monitors the operating status of the coal-fired unit or the internal combustion engine and adjusts the carbon dioxide capture rate of the CCUS unit and the methanol production of the synthesis reactor as needed.

[0054] In this embodiment, the methanol-to-electricity device 200 is a technology that can convert carbon dioxide and hydrogen into methanol through an electrocatalytic process. In this process, carbon dioxide can come from coal-fired power plants or other large fixed emission sources, and hydrogen can be obtained by electrolyzing water. Methanol, as a liquid fuel, can not only be used as a fuel for direct combustion, but also can be further processed into other chemicals as a chemical raw material.

[0055] The synthesized methanol is stored in specially designed containers that should have good sealing and corrosion resistance to ensure the quality of methanol and prevent leakage. In addition, the device is equipped with an advanced feedback control system that can monitor the working status of the coal-fired unit or internal combustion engine in real time and adjust the carbon dioxide capture rate of the CCUS unit and the methanol production of the synthesis reactor accordingly. In this way, it can be ensured that the right amount of methanol fuel can be provided under different operating conditions as auxiliary fuel required for equipment startup or stable combustion.

[0056] Example 3

[0057] Reference Figure 1-2 , which is the third embodiment of the present invention, and this embodiment further provides a comprehensive energy system coupled with a coal-fired power unit, an internal combustion engine, and an electric methanol production facility. The waste heat recovery device 400 collects the waste heat generated by the reaction during the purification reaction stage in the electric methanol production synthesis process. The waste heat recovery device 400 includes: at least one low-pressure heater, which is arranged before the material preheater, and is used to recover the heat in the electric methanol production process and to preheat the material entering the material preheater; a waste heat boiler, which is used to recover the heat generated by the exothermic reaction in the electric methanol production process and to generate low-pressure steam; a cooling device, which is arranged before the condenser, and is used to recover the unused heat in the electric methanol production process and convert this part of the heat into a usable energy form; the cooling device adopts water cooling or air cooling technology, and transfers the cooled heat to the steam-water system of the coal-fired unit through a heat exchanger.

[0058] In this embodiment, the coal-fired power unit 100, the internal combustion engine and the methanol-to-electricity facility are coupled and equipped with an efficient waste heat recovery device 400 to achieve the goal of comprehensive utilization of energy and energy conservation and emission reduction. Specifically, the system is designed with multi-stage waste heat recovery measures to fully utilize the waste heat generated in the methanol-to-electricity process, which not only improves energy utilization, but also reduces overall energy consumption.

[0059] The low-pressure heater is located before the material preheater. Its main function is to recover heat from the power-to-methanol process and use it to preheat the raw materials that will enter the material preheater. In this way, the external energy input required for preheating can be significantly reduced, thereby improving the overall energy efficiency of the system.

[0060] The waste heat boiler is designed to capture and utilize the waste heat generated by the exothermic reaction in the methanol production process. This waste heat is used to produce low-pressure steam, which not only reduces the demand for traditional heat sources, but also allows the low-pressure steam produced to be used in other links that require thermal energy, such as heating or auxiliary power generation.

[0061] The cooling device is usually installed in front of the condenser. Its function is to recover the heat that is not directly used in the process of methanol production and convert it into a form that can be reused. The cooling device can use water cooling or air cooling technology, and transfer this heat to the steam-water system of the coal-fired unit through a heat exchanger to achieve secondary utilization.

[0062] The specific workflow is as follows: First, the methanol production facility produces methanol through electrochemical reactions or other synthesis methods. A large amount of waste heat is generated in this process.

[0063] The waste heat is then captured by low-pressure heaters, waste heat boilers and chillers. The low-pressure heaters use the heat to preheat the incoming material, the waste heat boilers convert the waste heat into low-pressure steam, and the chillers convert the heat that cannot be directly used into other forms of energy.

[0064] Due to the close coordination between the various components, the energy efficiency of the entire system has been significantly improved. At the same time, the demand for external energy is reduced.

[0065] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0066] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0067] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0068] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An integrated energy system that couples coal-fired power units, internal combustion engines, and electricity-to-methanol facilities, characterized by: include, At least one coal-fired power generation unit (100) for providing load power output; An internal combustion engine coupled power generation system (101) for responding to rapidly changing power demands; The electric methanol device (200) is coupled with the coal-fired power generation unit and the internal combustion engine power generation unit, and is used to meet power regulation requirements according to power regulation requirements; The power system (300) is used to receive a power regulation demand signal of the power system (300) and reasonably distribute the regulation tasks between the coal-fired power generation unit (100) and the internal combustion engine coupled power generation system (101).

2. The integrated energy system of the coal-fired power unit, internal combustion engine and electric methanol production facility coupled as claimed in claim 1, characterized in that: The electric methanol production device (200) comprises: CCUS units, which capture carbon dioxide from flue gases emitted by coal-fired units or internal combustion engines; A water electrolysis unit for producing hydrogen; A synthesis reactor is equipped with a catalyst and is used to carry out a synthesis reaction between the carbon dioxide from the CCUS unit and the hydrogen from the water electrolysis unit to produce methanol.

3. The integrated energy system of the coal-fired power unit, internal combustion engine and methanol production facility coupled as claimed in claim 2 is characterized by: The CCUS unit adopts at least one of chemical absorption, physical absorption, adsorption or membrane separation technology.

4. The integrated energy system of the coal-fired power unit, internal combustion engine and methanol-to-electricity facility coupling as claimed in claim 3 is characterized by: The water electrolysis unit includes at least one of an alkaline water electrolyzer, a proton exchange membrane (PEM) water electrolyzer, or a solid oxide water electrolyzer (SOEC).

5. The integrated energy system of the coal-fired power unit, internal combustion engine and methanol-to-electricity facility coupled as claimed in claim 4 is characterized by: The electric methanol production device (200) includes heating carbon dioxide and hydrogen to at least 255°C to ensure that carbon dioxide and hydrogen undergo a methanol synthesis reaction under the action of a catalyst, and the reaction formula is as follows: CO2+3H2→CH3OH+H2O.

6. The integrated energy system of the coal-fired power unit, internal combustion engine and methanol-to-electricity facility coupled as claimed in claim 5, characterized in that: The electricity-to-methanol device (200) also includes a storage container for storing the generated methanol fuel so that it can be used as fuel for boiler stabilization or startup when needed by a coal-fired unit or an internal combustion engine.

7. The integrated energy system of the coal-fired power unit, internal combustion engine and methanol-to-electricity facility coupling according to claim 6 is characterized by: The power-to-methanol device (200) also includes a feedback control system, which monitors the operating status of the coal-fired unit or the internal combustion engine and adjusts the carbon dioxide capture rate of the CCUS unit and the methanol production of the synthesis reactor as needed.

8. The integrated energy system of the coal-fired power unit, internal combustion engine and electric methanol production facility coupled as claimed in claim 1, characterized in that: The waste heat recovery device (400) collects waste heat generated by the reaction during the purification reaction stage in the electro-methanol synthesis process.

9. The integrated energy system of the coal-fired power unit, internal combustion engine and methanol-to-electricity facility coupling as claimed in claim 8, characterized in that: The waste heat recovery device (400) comprises: At least one low-pressure heater, which is arranged before the material preheater and is used to recover heat in the process flow of methanol produced by electricity and to preheat the material entering the material preheater; A waste heat boiler, which is used to recover the heat generated by the exothermic reaction in the process of producing methanol from electricity and to generate low-pressure steam; The cooling device is arranged in front of the condenser and is used to recover the unused heat in the process of producing methanol from electricity and convert this part of the heat into a usable energy form.

10. The integrated energy system of the coal-fired power unit, internal combustion engine and methanol-to-electricity facility coupling according to claim 9, characterized in that: The cooling device adopts water cooling or air cooling technology, and transfers the cooled heat to the steam-water system of the coal-fired unit through a heat exchanger.

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