Phase change material reinforced heat storage type flue gas waste heat recovery enhancement system
Patent Information
- Application Number
- CN202522035691.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-22
- Publication Date
- 2026-09-25
- Estimated Expiration
- 2035-09-22
AI Technical Summary
然而，这种传统系统存在明显不足：工业烟气的温度和流量受生产工况影响较大，例如窑炉启停、原料更换等都会导致烟气温度在100-800℃大幅波动，此时换热器的换热效率会随之剧烈变化，无法保持稳定输出；当烟气流量骤降或温度低于150℃时，系统无法有效储存余热，导致后续热利用环节出现断供，连续性差，难以满足工业生产对热源稳定的需求
[0015]本实用新型通过相变材料层的潜热储存特性，在烟气热量充足时吸收热量，在烟气参数波动（如温度骤降、流量减少）时释放潜热，确保载热介质输出温度的波动范围控制在±3℃以内，解决了传统系统换热效率不稳定、热利用连续性差的问题。
Smart Images
Figure CN224802229U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of flue gas waste heat recovery technology, specifically to a flue gas waste heat recovery efficiency enhancement system that utilizes phase change materials to enhance heat storage function. Background Technology
[0002] In industrial production processes, the flue gas emitted by core equipment such as boilers and kilns often carries a large amount of waste heat. According to statistics, this type of flue gas waste heat accounts for 30%-50% of the total industrial waste heat. If it is directly released into the atmosphere, it will not only cause serious energy waste, but also raise the surrounding ambient temperature, exacerbate environmental heat pollution, and have an adverse impact on the ecological environment.
[0003] Most existing flue gas waste heat recovery systems use direct heat exchangers, transferring heat from the flue gas to heat transfer media such as cold water or air through metal tube walls. The heated heat transfer media is then used for production processes or heating. However, this traditional system has significant shortcomings: the temperature and flow rate of industrial flue gas are greatly affected by production conditions. For example, kiln start-up and shutdown, and raw material changes can cause flue gas temperatures to fluctuate significantly between 100-800℃. Under these conditions, the heat exchanger's efficiency will change drastically, making it impossible to maintain a stable output. When the flue gas flow rate drops sharply or the temperature falls below 150℃, the system cannot effectively store waste heat, leading to interruptions in subsequent heat utilization processes, poor continuity, and difficulty in meeting the stable heat source requirements of industrial production.
[0004] Phase change materials (PCMs) possess unique phase change properties, capable of absorbing or releasing substantial amounts of latent heat during phase change processes (such as solid-liquid transitions) while maintaining a relatively constant temperature. This characteristic makes them highly efficient heat storage media, enabling peak shaving and valley filling of heat. Applying PCMs to flue gas waste heat recovery systems can effectively mitigate the impact of flue gas parameter fluctuations on heat exchange. They store heat when the flue gas has sufficient heat and release it when heat is insufficient, thereby improving the stability and efficiency of waste heat recovery. Therefore, designing a structurally optimized flue gas waste heat recovery system that fully leverages the heat storage advantages of PCMs is urgently needed. Utility Model Content
[0005] The technical problem to be solved by this utility model is to provide a phase change material-enhanced heat storage flue gas waste heat recovery and efficiency improvement system, so as to realize efficient recovery, stable heat storage and continuous utilization of flue gas waste heat.
[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a phase change material enhanced heat storage flue gas waste heat recovery efficiency enhancement system, comprising a flue gas circulation component, a phase change heat storage component, and a heat exchange utilization component;
[0007] The flue gas flow assembly includes a flue gas inlet pipe, a flue gas outlet pipe, and a flue gas heat exchange channel. The two ends of the flue gas heat exchange channel are respectively connected to the flue gas inlet pipe and the flue gas outlet pipe. A flue gas flow regulating valve is provided on the flue gas inlet pipe.
[0008] The phase change heat storage component is disposed inside the flue gas heat exchange channel and includes a heat storage shell, a phase change material layer and heat exchange fins; the heat storage shell is a hollow structure and is filled with a phase change material layer; one end of the heat exchange fins is embedded in the phase change material layer and the other end extends into the flue gas heat exchange channel.
[0009] The heat exchange utilization component includes a heat transfer medium inlet pipe, a heat transfer medium outlet pipe, and a heat transfer medium channel. The heat transfer medium channel is attached to the outside of the heat storage shell, and its two ends are connected to the heat transfer medium inlet pipe and the heat transfer medium outlet pipe, respectively. The heat transfer medium inlet pipe is equipped with a medium circulation pump and a medium flow regulating valve.
[0010] Furthermore, the phase change material layer is provided with a plurality of uniformly distributed heat-conducting rods, which are arranged along the axial direction of the heat storage shell.
[0011] Furthermore, the phase change heat storage component is a multi-stage phase change heat storage structure, including multiple phase change material layers with different phase change temperatures. The phase change material layers are arranged sequentially in the flue gas heat exchange channel in order of decreasing phase change temperature along the flue gas flow direction, namely a high phase change temperature material layer, a medium phase change temperature material layer, and a low phase change temperature material layer.
[0012] Furthermore, temperature sensors are installed on the flue gas inlet pipe, the phase change material layer, and the heat transfer medium outlet pipe; the temperature sensors are connected to the PLC controller; the PLC controller is electrically connected to the flue gas flow regulating valve, the medium circulation pump, and the medium flow regulating valve.
[0013] Furthermore, it also includes a thermal insulation layer, which wraps around the outside of the flue gas heat exchange channel, the heat storage shell, and the heat transfer medium channel.
[0014] The beneficial effects of this utility model are as follows:
[0015] This invention utilizes the latent heat storage characteristics of the phase change material layer to absorb heat when the flue gas has sufficient heat and release latent heat when flue gas parameters fluctuate (such as a sudden drop in temperature or a reduction in flow rate), ensuring that the fluctuation range of the output temperature of the heat transfer medium is controlled within ±3℃, thus solving the problems of unstable heat exchange efficiency and poor heat utilization continuity in traditional systems.
[0016] This utility model's multi-stage phase change heat storage structure realizes the tiered storage of flue gas waste heat, further improving the waste heat recovery rate. It increases the heat storage capacity by more than 50% compared to traditional single-phase change material systems, adapting to the flue gas waste heat recovery needs in different temperature ranges.
[0017] The arrangement of heat exchange fins and heat conduction rods increases the heat exchange area between flue gas and phase change material, and also improves the internal heat conduction rate of phase change material, ensuring rapid absorption and release of waste heat. Attached Figure Description
[0018] The present invention will be further described below with reference to the accompanying drawings and embodiments.
[0019] Figure 1 This is a schematic diagram of the structure of this utility model.
[0020] Figure 2 This is a partial schematic diagram of a phase change thermal storage component. Detailed Implementation
[0021] The technical solution of this utility model will be clearly and completely described below through specific embodiments.
[0022] refer to Figure 1 and Figure 2 This utility model provides a phase change material-enhanced heat storage flue gas waste heat recovery and efficiency enhancement system, comprising a flue gas flow component, a phase change heat storage component, and a heat exchange and utilization component.
[0023] The flue gas flow assembly is used to guide high-temperature flue gas into the system and discharge it after heat exchange. The flue gas flow assembly includes a flue gas inlet pipe 1, a flue gas outlet pipe 2, and a flue gas heat exchange channel 3. The two ends of the flue gas heat exchange channel 3 are connected to the flue gas inlet pipe 1 and the flue gas outlet pipe 2, respectively. A flue gas flow regulating valve 10 is provided on the flue gas inlet pipe 1.
[0024] The phase change heat storage component is installed inside the flue gas heat exchange channel 3 to absorb and store waste heat in the flue gas. It includes a heat storage shell 4, a phase change material layer 5, and heat exchange fins 6. The heat storage shell 4 is a hollow metal structure filled with the phase change material layer 5. One end of the heat exchange fins 6 is embedded in the phase change material layer 5, and the other end extends into the flue gas heat exchange channel 3.
[0025] The phase change material layer 5 uses organic phase change materials (such as paraffin wax and fatty acids) or inorganic phase change materials (such as inorganic salts and metal alloys), with a phase change temperature range of 80-300℃, suitable for different flue gas temperature scenarios.
[0026] The heat exchange fins 6 are metal sheet structures (the material is the same as that of the heat storage shell 4). One end is fixed to the phase change material layer 5 by welding or embedded connection, and the other end extends into the flue gas heat exchange channel 3. The fin height is 30-80mm and the spacing is 20-50mm, which is used to expand the heat exchange area between the flue gas and the phase change material layer (5).
[0027] The heat exchange and utilization component is used to transfer the heat stored in the phase change heat storage component to the heat transfer medium, realizing waste heat reuse. It includes a heat transfer medium inlet pipe 7, a heat transfer medium outlet pipe 8, and a heat transfer medium channel 9. The heat transfer medium channel 9 is attached to the outside of the heat storage shell 4, and its two ends are connected to the heat transfer medium inlet pipe 7 and the heat transfer medium outlet pipe 8, respectively. The heat transfer medium inlet pipe 7 is equipped with a medium circulation pump 11 and a medium flow regulating valve 12. The medium circulation pump 11 drives the heat transfer medium (such as water or heat transfer oil) to flow within the heat transfer medium channel 9, and the medium flow regulating valve 12 regulates the heat transfer medium flow rate to control the heat exchange rate.
[0028] The phase change material layer 5 is provided with a plurality of uniformly distributed heat-conducting rods 15, which are arranged along the axial direction of the heat storage shell 4. The heat-conducting rods 15 are made of copper or aluminum alloy, with a diameter of 10-30 mm and a spacing of 50-100 mm, and are used to improve the thermal conductivity of the phase change material layer 5 and avoid local overheating or undercooling of the phase change material.
[0029] Example 2
[0030] In this embodiment, the phase change heat storage component is a multi-stage phase change heat storage structure, including multiple phase change material layers with different phase change temperatures. These phase change material layers are arranged sequentially along the flue gas flow direction within the flue gas heat exchange channel 3, in descending order of phase change temperature. They are a high phase change temperature material layer 18, a medium phase change temperature material layer 19, and a low phase change temperature material layer 20. This arrangement of phase change material layers in descending order of phase change temperature achieves gradient heat storage of the flue gas, thereby improving heat storage efficiency.
[0031] Temperature sensors are installed on flue gas inlet pipe 1, phase change material layer 5 and heat transfer medium outlet pipe 8; the temperature sensors are connected to a PLC controller; the PLC controller is electrically connected to flue gas flow regulating valve 10, medium circulation pump 11 and medium flow regulating valve 12.
[0032] Example 3
[0033] Based on Example 1, the system further includes an insulation layer, which wraps around the outside of the flue gas heat exchange channel 3, the heat storage shell 4, and the heat transfer medium channel 9. The insulation layer is made of rock wool, polyurethane, or aerogel material, with a thickness of 50-150 mm, to reduce heat loss.
[0034] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Those skilled in the art can make various modifications or equivalent substitutions to the present utility model within its substance and protection scope, and such modifications or equivalent substitutions should also be considered to fall within the protection scope of the present utility model's technical solution.
Claims
1. A phase change material-enhanced heat storage flue gas waste heat recovery and efficiency improvement system, characterized in that: Flue gas circulation components, phase change heat storage components, and heat exchange and utilization components; The flue gas flow assembly includes a flue gas inlet pipe (1), a flue gas outlet pipe (2) and a flue gas heat exchange channel (3). The two ends of the flue gas heat exchange channel (3) are connected to the flue gas inlet pipe (1) and the flue gas outlet pipe (2) respectively. A flue gas flow regulating valve (10) is provided on the flue gas inlet pipe (1). The phase change heat storage component is disposed inside the flue gas heat exchange channel (3) and includes a heat storage shell (4), a phase change material layer (5) and heat exchange fins (6); the heat storage shell (4) is a hollow structure and is filled with a phase change material layer (5); one end of the heat exchange fins (6) is embedded in the phase change material layer (5) and the other end extends into the flue gas heat exchange channel (3); The heat exchange utilization component includes a heat transfer medium inlet pipe (7), a heat transfer medium outlet pipe (8), and a heat transfer medium channel (9). The heat transfer medium channel (9) is attached to the outside of the heat storage shell (4), and its two ends are connected to the heat transfer medium inlet pipe (7) and the heat transfer medium outlet pipe (8) respectively. The heat transfer medium inlet pipe (7) is equipped with a medium circulation pump (11) and a medium flow regulating valve (12).
2. The phase change material-enhanced heat storage flue gas waste heat recovery and efficiency improvement system according to claim 1, characterized in that: The phase change material layer (5) is provided with a plurality of uniformly distributed heat-conducting rods (15), which are arranged along the axial direction of the heat storage shell (4).
3. The phase change material-enhanced heat storage flue gas waste heat recovery and efficiency improvement system according to claim 1, characterized in that: The phase change heat storage component is a multi-stage phase change heat storage structure, including multiple phase change material layers with different phase change temperatures. The phase change material layers are arranged in the flue gas heat exchange channel (3) in order of phase change temperature from high to low, and are respectively a high phase change temperature material layer (18), a medium phase change temperature material layer (19), and a low phase change temperature material layer (20).
4. The phase change material-enhanced heat storage flue gas waste heat recovery and efficiency improvement system according to claim 1, characterized in that: Temperature sensors are installed on the flue gas inlet pipe (1), the phase change material layer (5) and the heat transfer medium outlet pipe (8); the temperature sensors are connected to the PLC controller; the PLC controller is electrically connected to the flue gas flow regulating valve (10), the medium circulation pump (11) and the medium flow regulating valve (12).
5. The phase change material-enhanced heat storage flue gas waste heat recovery and efficiency improvement system according to claim 1, characterized in that: It also includes a heat insulation layer, which is wrapped around the outside of the flue gas heat exchange channel (3), the heat storage shell (4) and the heat transfer medium channel (9).