Heat accumulating type heat exchanger for coal gas power generation

Abstract

The utility model relates to a heat accumulating type heat exchanger for coal gas power generation, and belongs to the field of heat exchangers. The heat exchanger comprises a heat storage bin, a circulating fan, a circulating air bin, a smoke bin and a coal gas bin, all the bins are integrated in a cylinder capable of rotating around a central shaft, and the cylinder is divided into three independent bins. The heat storage bin is filled with a heat storage body, and circulating air is driven by the circulating fan to transfer surplus heat between the smoke bin and the heat storage bin for storage, or heat is released between the heat storage bin and the coal gas bin to heat coal gas entering the furnace. The device controls the switching of a heat storage mode and a heat release mode through the rotation of the cylinder body, and realizes the dynamic balance of heat under the fluctuation of the calorific value of coal gas in combination with an adjustable air valve and an enhanced heat exchange structure. According to the scheme, the stability of a gas power generation system is remarkably improved, temperature fluctuation of gas entering a furnace is reduced, load fluctuation of a generator set is reduced, the heat storage efficiency is improved, meanwhile, the modular expansion capacity is achieved, the system is suitable for single-machine or multi-machine cooperative operation, the energy utilization rate is effectively increased, and the equipment maintenance cost is reduced.

Description

Technical Field

[0001] This utility model belongs to the field of heat exchangers and relates to a heat storage heat exchanger for gas power generation. Background Technology

[0002] In the iron and steel metallurgical industry, coal gas power generation is an important energy recovery method. By introducing blast furnace gas and coke oven gas generated during the smelting process into generator units for combustion and power generation, both energy efficiency and environmental pollution reduction are achieved. However, in actual operation, due to fluctuations in the quality of coal and coke fed into the furnace and adjustments to the production process, the calorific value and supply of coal gas often show significant changes. This fluctuation directly affects the stability of the coal gas at the boiler inlet, which in turn leads to frequent fluctuations in the load of the turbine generator unit, reducing power generation efficiency, accelerating equipment wear, and even causing shutdown failures.

[0003] In existing technologies, a common approach to address gas fluctuation issues is to use a combined control strategy involving a boiler inlet gas regulating valve and a calorific value analyzer. By monitoring the gas calorific value in real time, the regulating valve dynamically adjusts the gas flow rate to maintain combustion stability. However, this method has significant limitations: firstly, frequent valve operation can lead to wear and tear on mechanical components, increasing maintenance costs; secondly, when gas calorific value fluctuations are large or prolonged, relying solely on flow rate adjustment cannot completely offset the impact of calorific value changes, and the generator unit may still deviate from its efficient operating range. Furthermore, some technologies attempt to use fixed thermal storage devices to store excess heat, but these lack dynamic coordination between heat storage and release processes, making it impossible to flexibly switch modes according to real-time operating conditions. This results in low thermal storage efficiency and makes it difficult to meet the complex requirements of gas-fired power generation systems.

[0004] Existing heat exchanger designs mostly employ static structures, such as traditional shell-and-tube or plate heat exchangers. Their heat exchange paths are fixed, making it difficult to adapt to dynamic changes in gas flow rate and calorific value. For example, when the calorific value of the gas suddenly increases, excess waste heat from the flue gas cannot be stored in time, leading to heat waste. Conversely, when the calorific value of the gas drops sharply, existing systems lack effective heat replenishment mechanisms, causing the temperature of the gas entering the furnace to decrease, further exacerbating the unstable operation of the generator unit. Furthermore, while some literature mentions regenerative heat exchangers that can store some heat, their structural design limits the heat exchange efficiency between the regenerator and the circulating medium, resulting in low efficiency and an inability to achieve rapid switching between multiple operating conditions. This leads to sluggish system response, making it difficult to meet the stringent requirements for dynamic regulation in actual industrial scenarios.

[0005] In summary, existing thermal management solutions for coal gas power generation systems still have significant shortcomings: first, they rely on mechanical adjustment methods, making it difficult to cope with large fluctuations; second, the heat storage and release processes lack dynamic coordination, resulting in insufficient system flexibility; and third, the fixed structure of heat exchangers cannot efficiently match changing operating conditions. These problems severely restrict the improvement of coal gas power generation efficiency and the long-term stable operation of equipment. Utility Model Content

[0006] In view of this, the purpose of this utility model is to provide a heat storage heat exchanger for coal gas power generation, so as to realize real-time regulation of heat storage and release, adapt to coal gas fluctuations, and have efficient heat exchange capabilities, thereby improving the overall performance and reliability of coal gas power generation systems.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A heat storage heat exchanger for gas power generation includes a heat storage chamber, a flue gas chamber, and a gas chamber inside a cylindrical body. The cylindrical body is rotatable around a central axis and its interior is divided into three independent chambers, corresponding to the heat storage chamber, flue gas chamber, and gas chamber, respectively.

[0009] The heat storage chamber is equipped with a heat storage body, which is a porous medium or a phase change material.

[0010] The flue gas chamber is connected to the boiler flue gas passage and is used to receive high-temperature flue gas and exchange heat.

[0011] The gas chamber is connected to the boiler inlet gas channel and is used to heat the inlet gas.

[0012] A circulating air chamber is set up, which is connected to the heat storage chamber and the flue gas chamber respectively by a circulating fan, to form a circulating air loop;

[0013] The circulating fan is configured as follows:

[0014] Under conditions where the calorific value of the gas is high or the volume of flue gas is large, the waste heat in the flue gas chamber is transported to the heat storage chamber for storage via circulating air.

[0015] When the calorific value of the gas is low or the flue gas volume is small, the heat in the heat storage chamber is transferred to the gas chamber through circulating air to heat the gas entering the furnace.

[0016] Optionally, the heat storage chamber and the circulating air chamber are connected by a closed air duct, and the heat storage body and the circulating air transfer heat through an indirect heat exchange method.

[0017] Optionally, the heat exchange path between the flue gas chamber and the gas chamber is switched by rotating the cylinder, so that the waste heat of the flue gas chamber can be directly or indirectly transferred to the gas chamber.

[0018] Optionally, the cylinder can rotate clockwise or counterclockwise to adjust the heat exchange position between the flue gas chamber, the gas chamber, and the circulating air chamber.

[0019] Optionally, the heat storage medium of the heat storage chamber is a molten salt material or a ceramic-based porous medium.

[0020] Optionally, an adjustable air valve is provided between the circulating air chamber and the flue gas chamber to control the circulating air volume to adapt to different working conditions.

[0021] Optionally, the gas chamber is equipped with an enhanced heat exchange structure, including fins or corrugated plates, to improve the heat exchange efficiency between the gas and the circulating air or flue gas.

[0022] Optionally, the device is suitable for use by one or more generator sets, and heat distribution and regulation are achieved through an external pipeline system.

[0023] Optionally, the cylinder is cylindrical.

[0024] The beneficial effects of this utility model are as follows:

[0025] This solution provides a gas-fired power generation thermal storage heat exchanger, which, through innovative structural design and dynamic thermal management mechanism, demonstrates significant technical advantages in industrial scenarios with frequent gas fluctuations. Its core beneficial effects are reflected in the following aspects:

[0026] Firstly, through a modular design integrating a heat storage chamber, a circulating air chamber, a flue gas chamber, and a gas chamber, efficient heat storage and flexible allocation are achieved. The heat storage chamber is filled with porous media or phase change materials (such as molten salt), whose high specific surface area and latent heat of phase change significantly improve heat storage density and thermal response speed. When the calorific value of the gas increases or the flue gas volume increases, the circulating fan transports excess heat from the flue gas chamber to the heat storage chamber for storage, avoiding heat waste. Conversely, when the calorific value of the gas decreases or the supply is insufficient, the heat storage chamber releases the stored heat to the gas chamber through reverse circulation, directly heating the gas fed into the furnace. This dynamic adjustment mechanism of "peak shaving and valley filling" effectively smooths out fluctuations in the calorific value and flow rate of the gas, stabilizing the boiler combustion conditions, thereby significantly reducing load fluctuations in the turbine generator set, extending equipment service life, and reducing mechanical failures caused by frequent adjustments.

[0027] Secondly, the compartmentalized structure of the cylindrical shell rotating around its central axis overcomes the functional limitations of traditional fixed heat exchangers. The shell is internally divided into three independent compartments: a heat storage compartment, a flue gas compartment, and a gas compartment. By rotating and switching heat exchange paths, rapid response under various operating conditions is achieved. For example, when the flue gas compartment heats up due to high-temperature flue gas heat exchange, the shell rotates to align it with the circulating air compartment, using the circulating air to transfer heat to the heat storage compartment. When additional heat is needed, the shell rotates to connect the heat storage compartment with the gas compartment, releasing heat to the gas compartment through the circulating air. This dynamic rotation design not only simplifies the piping layout but also avoids the complex control logic of valve switching in traditional systems, significantly improving system reliability and ease of maintenance. Furthermore, the adjustability of the rotation direction (clockwise or counterclockwise) further enhances the device's adaptability to complex operating conditions.

[0028] Furthermore, the optimized design of the circulating air system further enhances energy utilization efficiency. The circulating air chamber is connected to the flue gas chamber and heat storage chamber via a closed-loop duct, and the airflow is precisely controlled by adjustable valves to ensure efficient and stable heat transfer. The circulating air, acting as a heat carrier, seamlessly switches between heat storage and heat release modes, avoiding direct mixing and contamination of flue gas and coal gas, while ensuring the purity of the medium through indirect heat exchange. The enhanced heat exchange structure (such as fins or corrugated plates) added to the coal gas chamber further improves the heat exchange efficiency between coal gas and circulating air or flue gas, ensuring rapid heat transfer to the incoming coal gas and reducing heat loss.

[0029] Finally, the modularity and scalability of this device offer significant advantages for industrial applications. The regenerative heat exchanger can operate independently of a single generator set, or it can achieve heat sharing and coordinated control among multiple units through an external piping system. This design is particularly suitable for complex scenarios involving multiple generator sets operating in parallel within steel plants, enabling dynamic allocation of heat resources based on real-time demand and improving the overall system's energy efficiency. Furthermore, the molten salt or porous ceramic materials used in the heat storage chamber possess high-temperature resistance and corrosion resistance, significantly reducing long-term maintenance costs and replacement frequency.

[0030] In summary, this solution, through the organic combination of dynamic heat storage and release mechanism, rotating compartment structure, high-efficiency circulating air system and modular design, not only solves the problem of unstable generator operation caused by gas fluctuations, but also significantly improves energy utilization efficiency and system reliability, providing an innovative solution that is both economical and practical for the field of gas power generation.

[0031] Other advantages, objectives, and features of this invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination and study, or may be learned from practice of this invention. The objectives and other advantages of this invention can be realized and obtained through the following description. Attached Figure Description

[0032] To make the objectives, technical solutions, and advantages of this utility model clearer, the preferred embodiments of this utility model will be described in detail below with reference to the accompanying drawings, wherein:

[0033] Figure 1 This is a schematic diagram of one embodiment of the present solution.

[0034] Attached diagram labels: 1. Heat storage chamber, 2. Circulating fan, 3. Circulating air chamber, 4. Flue gas chamber, 5. Gas chamber. Detailed Implementation

[0035] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this utility model. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0036] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0037] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0038] Please see Figure 1 The core structure of the regenerative heat exchanger includes a cylindrical body, the interior of which is evenly divided into three independent compartments along the axial direction: a heat storage compartment 1, a flue gas compartment 4, and a gas compartment 5. The body rotates around its central axis via an external drive mechanism, and the rotation direction can be set to clockwise or counterclockwise according to operating conditions. Both ends of the body are connected to the boiler flue gas outlet and the boiler gas inlet via sealing flanges, respectively, to ensure no leakage occurs during the switching process between the high-temperature flue gas and the gas compartments.

[0039] The heat storage chamber 1 is filled with a heat storage medium, which is either a porous ceramic medium or a molten salt phase change material. The porous ceramic medium has a high specific surface area and high temperature resistance, enabling it to quickly absorb and store waste heat from the flue gas; the molten salt material achieves high-density heat storage through a phase change process. The outer wall of the heat storage chamber 1 is equipped with an insulation layer to reduce heat loss. The circulating air chamber 3 is connected to the heat storage chamber 1 via a closed air duct. A circulating fan 2 is installed inside the circulating air chamber 3, and the circulating fan 2 uses frequency conversion control to adjust the airflow according to system requirements.

[0040] Flue gas chamber 4 is directly connected to the boiler flue gas outlet and has a serpentine heat exchange pipe inside, where high-temperature flue gas exchanges heat with the chamber wall as it flows through the pipe. Gas chamber 5 is connected to the boiler's inlet gas pipe, and its inner wall is welded with corrugated fins to increase the heat exchange area and improve gas heating efficiency. Temperature sensors are installed at the inlet and outlet of both flue gas chamber 4 and gas chamber 5 to monitor the medium temperature in real time and feed it back to the control system.

[0041] Workflow Description

[0042] 1. Thermal storage mode (when the calorific value of the gas is high or the flue gas volume is large)

[0043] When the calorific value of the gas increases or the flue gas volume increases, the high-temperature flue gas enters the flue gas chamber 4, where heat is transferred to the chamber walls through internal heat exchange pipes. The control system drives the cylinder to rotate, aligning the flue gas chamber 4 with the circulating air chamber 3. At this time, the circulating fan 2 starts, forcibly circulating the air in the circulating air chamber 3. After absorbing heat from the high-temperature flue gas chamber 4 walls, the air enters the heat storage chamber 1. The circulating air transfers heat to the heat storage medium in the heat storage chamber 1, which stores energy through sensible heat or latent heat of phase change. After heat storage is completed, the circulating air is cooled and returned to the circulating air chamber 3, forming a closed loop.

[0044] 2. Heat release mode (when the calorific value of the gas is low or the flue gas volume is small)

[0045] When the calorific value of the gas decreases or the supply is insufficient, the control system drives the cylinder to rotate, aligning the heat storage chamber 1 with the gas chamber 5. The circulating fan 2 reverses direction, drawing circulating air from the heat storage chamber 1. After absorbing the stored heat on the surface of the heat storage body, the circulating air enters the gas chamber 5. The high-temperature circulating air efficiently transfers heat to the incoming gas through the finned structure of the gas chamber 5, raising the gas temperature to the set range. The reheated circulating air returns to the circulating air chamber 3, resuming the next cycle.

[0046] 3. Dynamic adjustment and multi-unit coordination

[0047] The device can automatically switch between heat storage and heat release modes according to real-time operating conditions. For example, when the gas supply suddenly increases, the cylinder quickly rotates to connect the heat storage chamber 1 with the flue gas chamber 4 to prioritize the storage of excess heat; when multiple generator sets are running in parallel, the external pipeline system can interconnect the heat storage chambers 1 of different devices to realize the cross-unit allocation of heat and ensure the efficient and stable operation of the overall system.

[0048] Key component details

[0049] Circulating fan 2: It adopts high-temperature resistant alloy blades and is driven by a variable frequency motor. The air volume adjustment range is 30%-120% of the rated value to adapt to different heat storage and release intensity requirements.

[0050] Connection structure between heat storage chamber 1 and circulating air chamber 3: The inner wall of the air duct is coated with a ceramic coating to prevent corrosion from high-temperature airflow, and an adjustable air valve is provided between the air ducts to balance the air pressure.

[0051] Cylinder rotation control: The external drive mechanism adopts a servo motor and gear transmission system, with a rotation angle accuracy of ±1°, ensuring the sealing and reliability of the chamber docking.

[0052] The above embodiments are merely typical implementations of the present invention. Those skilled in the art can adjust the specific structure or parameters without departing from the core design of the present invention, and such adjustments should be considered to fall within the protection scope of the present invention.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of this technical solution, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A heat storage heat exchanger for gas-fired power generation, characterized in that: A heat storage chamber (1), a flue gas chamber (4) and a gas chamber (5) are provided inside the cylinder. The cylinder is rotatable around the central axis. The inside of the cylinder is divided into three independent chambers, which correspond to the heat storage chamber (1), the flue gas chamber (4) and the gas chamber (5) respectively. The heat storage chamber (1) is equipped with a heat storage body, which is a porous medium or a phase change material; The flue gas chamber (4) is connected to the boiler flue gas passage and is used to receive high-temperature flue gas and exchange heat. The gas chamber (5) is connected to the boiler gas inlet channel and is used to heat the gas entering the boiler. A circulating air chamber (3) is set up to be connected to the heat storage chamber (1) and the flue gas chamber (4) respectively by a circulating fan (2) to form a circulating air circuit; The circulating fan (2) is configured as follows: Under conditions where the calorific value of the gas is high or the flue gas volume is large, the waste heat in the flue gas chamber (4) is transported to the heat storage chamber (1) for storage through circulating air. When the calorific value of the gas is low or the flue gas volume is small, the heat in the heat storage chamber (1) is transported to the gas chamber (5) through the circulating air to heat the gas entering the furnace.

2. The gas-fired power generation heat storage heat exchanger according to claim 1, characterized in that: The heat storage chamber (1) and the circulating air chamber (3) are connected by a closed air duct, and the heat storage body and the circulating air transfer heat through an indirect heat exchange method.

3. The gas-fired power generation heat storage heat exchanger according to claim 1, characterized in that: The heat exchange path between the flue gas chamber (4) and the gas chamber (5) is switched by rotating the cylinder, so that the waste heat of the flue gas chamber (4) is directly or indirectly transferred to the gas chamber (5).

4. The gas-fired power generation heat storage heat exchanger according to claim 1, characterized in that: The cylinder rotates clockwise or counterclockwise, and the heat exchange position between the flue gas chamber (4), the gas chamber (5) and the circulating air chamber (3) is adjusted by rotating the cylinder.

5. The gas-fired power generation regenerative heat exchanger according to claim 1, characterized in that: The heat storage medium of the heat storage chamber (1) is a molten salt material or a ceramic-based porous medium.

6. The gas-fired power generation heat storage heat exchanger according to claim 1, characterized in that: An adjustable air valve is provided between the circulating air chamber (3) and the flue gas chamber (4) to control the circulating air volume to adapt to different working conditions.

7. The gas-fired power generation regenerative heat exchanger according to claim 1, characterized in that: The gas chamber (5) is equipped with an enhanced heat exchange structure, including fins or corrugated plates, to improve the heat exchange efficiency between the gas and the circulating air or flue gas.

8. The gas-fired power generation heat storage heat exchanger according to claim 1, characterized in that: The gas-fired power generation heat storage heat exchanger is suitable for use by one or more generator sets, and heat distribution and regulation are achieved through an external pipeline system.

9. The regenerative heat exchanger for coal gas power generation according to claim 1, characterized by: The cylinder is cylindrical.

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