Combustible gas reformer preheater

Abstract

The application provides a combustible gas reforming preheater and relates to the field of reforming preheaters.The combustible gas reforming preheater comprises a reforming reactor cylinder, two support bases are fixedly arranged at the bottom of the outer end face of the reforming reactor cylinder, the support bases on the two sides are symmetrically arranged, an inner cavity is arranged in the reforming reactor cylinder, and the reforming reactor cylinder is divided into an outer protection plate, a heat insulation layer and a refractory insulation layer from outside to inside.The combustible gas reforming preheater is integrally designed by adopting a horizontal cylinder reactor without a catalyst bed and an integrated countercurrent heat exchanger, the system pressure drop and the equipment structure complexity are effectively reduced, the unique cross countercurrent heat exchange layout is matched with the whole finned tube, the waste heat recovery efficiency is significantly improved, the raw material gas preheating temperature is greatly improved, the electric heating closed loop control system based on the real-time feedback of the outlet temperature realizes the accurate and stable control of the strong endothermic reforming reaction temperature, and the conversion rate and the operation safety are improved.

Description

Technical Field

[0001] This invention relates to the field of reforming preheater technology, specifically a combustible gas reforming preheater. Background Technology

[0002] In the fields of energy and chemical engineering, city gas, methanol synthesis, hydrogen production and various synthesis gas preparation, it is often necessary to reform a mixed combustible gas containing components such as carbon monoxide, hydrogen, methane, carbon dioxide, nitrogen, and water vapor to adjust its calorific value, hydrogen-to-carbon ratio or reduce the content of specific components in order to generate a mixed reformed gas with hydrogen and carbon monoxide as the main target products.

[0003] Currently, industrial plants that realize the above-mentioned reforming reaction mainly use axial fixed-bed reactors or tubular steam reformers. Although axial fixed-bed reactors have a relatively simple structure, the feed gas needs to flow through the entire height of the catalyst bed, resulting in a long flow path and high resistance, which leads to a significant increase in system pressure drop and increases compressor energy consumption.

[0004] On the other hand, tubular reactors, such as steam reformers, while providing a relatively uniform reaction temperature field by heating multiple parallel reaction tubes through an externally heated furnace, have extremely complex structures involving thousands of slender reaction tubes and intricate tube sheet and manifold systems, resulting in high manufacturing costs and difficult maintenance. These devices are typically suitable for large-scale, continuous industrial production, but are ill-suited to the needs of small- to medium-scale gas processing or intermittent operation in terms of investment costs and operational flexibility. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a combustible gas reforming preheater, which solves the problems mentioned in the background section.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a combustible gas reforming preheater, comprising a reforming reactor cylinder, two support bases fixedly disposed at the bottom of the outer end face of the reforming reactor cylinder, the support bases on both sides being symmetrically arranged, an inner cavity within the reforming reactor cylinder, the reforming reactor cylinder being divided from the outside to the inside into an outer protective plate, a heat insulation layer, and a fire-resistant insulation layer, a preheating raw material gas conveying pipe connected to one end of the reforming reactor cylinder, a burner interface connected to one end of the preheating raw material gas conveying pipe, a burner installed and connected to one end of the burner interface, a gas inlet connected to one end of the burner, a raw material gas input channel provided inside the burner, a hot reforming gas conveying pipe connected to the other side of the reforming reactor cylinder, the hot reforming gas conveying pipe communicating with the inner cavity of the cylinder, a preheater shell installed and connected to one end of the hot reforming gas conveying pipe, a reforming gas outlet connected to one end of the preheater shell, and no catalyst bed layer provided inside the inner cavity of the cylinder.

[0007] Preferably, the preheater shell is provided with a heat exchange tube bundle, and the preheater shell is made of a preheater insulation shell.

[0008] Preferably, the preheater shell is provided with a shell-side flow channel, and the two sides of the shell-side flow channel are connected with shell-side flow channel openings.

[0009] Preferably, a third temperature sensor is installed at the connection position between the hot reforming gas delivery pipe and the preheater shell, and the third temperature sensor is used to detect the reforming gas outlet temperature.

[0010] Furthermore, a preheated gas inlet is installed at the connection position between the preheated raw material gas conveying pipe and the reforming reactor shell. A second temperature sensor is installed at one end of the preheated gas inlet, which is used to detect the temperature of the preheated raw material gas.

[0011] Furthermore, an oxygen supply interface is installed on one side of the burner, and a flow meter is installed at the interface to detect the flow rate of the raw gas pipe passing through the burner. This data can be combined with temperature data to verify the heat exchange effect and calculate the heat balance.

[0012] Preferably, a first temperature sensor is installed on one side of the gas inlet to detect the gas inlet temperature.

[0013] Preferably, the outer wall of the reforming reactor shell is regularly arranged with electric heating tubes along its central axis, and the electric heating tubes are the core of achieving uniform and controllable heating.

[0014] This invention provides a combustible gas reforming preheater. It has the following beneficial effects: 1. The device of this invention does not use a catalyst for reaction, does not require a catalyst bed, has a simple structure, a large flow cross-sectional area, and a short reaction path, which can significantly reduce equipment resistance and save energy.

[0015] 2. For strongly endothermic reforming reactions, temperature fluctuations can severely affect reaction equilibrium and rate. Therefore, temperature sensors are installed at both the inlet and outlet to monitor temperature changes in real time and provide rapid feedback adjustments, achieving precise and stable control of the reaction temperature, thereby improving the reforming reaction conversion rate.

[0016] 3. The device of this invention has a simplified and compact structure, low manufacturing cost, and wide applicability. The device eliminates the thousands of slender reaction tubes and complex tube sheet structure inside the shell-and-tube reactor, and also simplifies the internal piping and distributors between multiple sections of adiabatic bed. The structure is very compact and simple, which not only reduces the amount of materials used and the difficulty and cost of manufacturing, but also makes the device easy to modularly design and scale up. This design is particularly suitable for small and medium-sized gas treatment projects, and has greater application flexibility.

[0017] 4. The internal electric heating elements can automatically control the number of heating elements based on temperature changes. The automatic control system can promptly understand the reaction status and provide early warning and intervention for possible abnormal temperature rises. This feature greatly enhances the safety of the equipment operation and the level of precision in process control, providing a guarantee for long-term, stable operation. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the external structure of the present invention; Figure 2 This is a side view of the external structure of the present invention; Figure 3 This is a front view of the external structure of the present invention; Figure 4 This is a cross-sectional view of the present invention along the AA direction.

[0019] In the diagram: 101, Reformer reactor shell; 102, Preheater shell; 103, Gas inlet; 104, Reformer gas outlet; 105, Burner interface; 106, Electric heating tube; 107, Heat exchanger tube bundle; 108, Shell-side flow channel; 109, First temperature sensor; 110, Preheated gas inlet; 111, Third temperature sensor; 112, Burner oxygen supply interface; 113, Preheated raw material gas delivery pipe; 114, Hot reformer gas delivery pipe; 115, Refractory insulation layer; 116, Thermal insulation layer; 117, Outer protective plate; 118, Preheater insulation shell; 119, Support base; 120, Shell-side flow channel opening; 121, Inner cavity of the reactor shell; 122, Burner. Detailed Implementation

[0020] This invention provides a combustible gas reforming preheater, such as... Figure 1-4 As shown, the reactor includes a reforming reactor body 101, which is a horizontally placed cylindrical structure. Two support bases 119 are fixedly installed at the bottom of the outer end face of the reforming reactor body 101, with the support bases 119 on both sides symmetrically positioned. The reforming reactor body 101 has an inner cavity 121. From the outside to the inside, the reforming reactor body 101 consists of an outer protective plate 117, a heat insulation layer 116, and a refractory insulation layer 115. One end of the reforming reactor body 101 is connected to a preheated raw material gas conveying pipe 113, through which the preheated raw material gas... One end of the conveying pipe 113 is connected to a burner interface 105, and a burner 122 is installed and connected to one end of the burner interface 105. One end of the burner 122 is connected to a gas inlet 103, and a raw material gas input channel is provided inside the burner 122. The other side of the reforming reactor shell 101 is connected to a hot reforming gas conveying pipe 114, which is connected to the inner cavity 121 of the shell. One end of the hot reforming gas conveying pipe 114 is connected to a preheater shell 102, and one end of the preheater shell 102 is connected to a reforming gas outlet 104.

[0021] It should be further explained that the raw material gas input into the gas inlet 103 is preheated by the burner 122 and then enters the inner cavity 121 of the cylinder through the preheated raw material gas delivery pipe 113.

[0022] It should be further explained that the refractory insulation layer 115 is made of refractory material, the heat insulation layer 116 uses heat insulation materials such as insulation cotton, and the outer protective plate 117 is made of stainless steel plate.

[0023] Furthermore, a heat exchange tube bundle 107 is provided inside the preheater shell 102. The preheater shell 102 is made of a preheater insulation shell 118, and the heat exchange tube bundle 107 is a finned tube heat exchange tube bundle.

[0024] Furthermore, the preheater shell 102 is provided with a shell-side flow channel 108 inside the shell, and the two sides of the shell-side flow channel 108 are connected with shell-side flow channel openings 120.

[0025] It should be further explained that the heat exchange tube bundle (107) and the shell-side flow channel (108) constitute a countercurrent heat exchange structure for the feed gas and reformed gas to flow in opposite directions for heat exchange.

[0026] Furthermore, a third temperature sensor 111 is installed at the connection point between the hot reforming gas delivery pipe 114 and the preheater shell 102. The third temperature sensor 111 is used to detect the reforming gas outlet temperature.

[0027] Furthermore, a preheating gas inlet 110 is installed at the connection position between the preheating raw material gas conveying pipe 113 and the reforming reactor shell 101. A second temperature sensor is installed at one end of the preheating gas inlet 110, which is used to detect the temperature of the preheated raw material gas.

[0028] Furthermore, a burner oxygen supply interface 112 is installed on one side inside the burner 122. A flow meter is installed at the interface to detect the flow rate in the raw gas pipeline passing through the burner 122. This data can be combined with temperature data to verify the heat exchange effect and calculate the heat balance.

[0029] Furthermore, a first temperature sensor 109 is installed on one side of the gas inlet 103 to detect the gas inlet temperature.

[0030] Furthermore, electric heating tubes 106 are regularly arranged on the outer wall of the reforming reactor cylinder 101 along its central axis, and the electric heating tubes 106 are the core of achieving uniform and controllable heating.

[0031] It should be further explained that the electric heating tube 106 is connected to the third temperature sensor 111 and connected to an external automatic heating control system. When the third temperature sensor 111 detects that the reforming gas outlet temperature is lower than the set reaction temperature, such as 1260°C, the control system can automatically start some or all of the electric heating tube groups. By adjusting the number of energized groups, the system can dynamically and accurately compensate for the reaction heat consumption and maintain the reaction temperature stability.

[0032] The usage method of this solution is as follows: S1. Confirm that all connecting pipes of the device are properly sealed and that the wiring of the electric heating system, temperature sensor and flow meter to the control system is correct; Connect the external raw material gas source to the gas inlet 103 and connect the reformed gas output pipeline to the reformed gas outlet 104. The target reaction temperature, such as 1260°C, and other safe operating parameters are set through the control system.

[0033] S2. Open the raw material gas supply valve to allow the mixed combustible gas, including CO, to enter. , , , , The gas enters the gas inlet 103 at a certain flow rate. The raw gas first flows through the first temperature sensor 109 installed here, which detects and provides real-time feedback on the initial temperature (T1) of the raw gas. Meanwhile, the raw gas flows through a pipeline and passes through a flow meter, which monitors and records the volumetric or mass flow rate (F) of the raw gas in real time, providing basic data for subsequent energy balance calculations and process monitoring.

[0034] S3. The raw material gas then enters the heat exchange tube bundle 107, i.e. the tube side, inside the preheater shell 102; Meanwhile, if the device is being started for the first time or requires rapid heating, the burner 122 and / or the electric heating tube 106 can be activated to heat the inner cavity 121 of the reforming reactor shell 101. Once the reaction begins, the high-temperature reforming product gas is introduced from the inner cavity 121 through the hot reforming gas delivery pipe 114 into the shell-side flow channel 108 of the preheater shell 102; The high-temperature reformed gas flows laterally through the shell-side flow channel 108, sweeping across the outside of the heat exchange tube bundle 107, especially the finned part, and performs efficient cross-counterflow heat exchange with the cold raw material gas flowing in the opposite direction inside the tube bundle. During this process, the cold raw gas is gradually heated while the hot reformed gas is gradually cooled. After this deep heat exchange, the temperature of the raw gas when it leaves the heat exchange tube bundle 107 can be measured by the second temperature sensor (T2). The preheated high-temperature feed gas is then transported to the reforming reactor shell 101 through the preheated feed gas delivery pipe 113.

[0035] S4. The high-temperature raw material gas enters the inner cavity 121 of the cylinder through the inlet near the burner interface 105. No catalyst bed is set in the inner cavity 121. The raw material gas is mainly heated by two heat sources in the inner cavity 121: one is the radiant heat provided by the flame injected by the burner 122, and the other is the uniform and controllable heat field provided by the electric heating tubes 106 arranged around the cylinder. In high-temperature environments below 1300℃, the refractory insulation layer 115 withstands the methane in the raw material gas ( ),carbon dioxide( ),water vapor( Components such as carbon monoxide (CO) and hydrogen undergo an endothermic reforming reaction, converting into carbon monoxide (CO) and hydrogen gas. Syngas with syngas as the primary target product; Because there is no catalyst bed resistance, and the gas has a short flow path and a large flow cross section in the horizontal cylinder, the system pressure drop is significantly lower than that of a traditional axial fixed bed reactor.

[0036] S5. The high-temperature reforming gas generated after the reaction leaves the inner cavity 121 of the cylinder and enters the hot reforming gas delivery pipe 114. A third temperature sensor 111 installed in addition continuously detects the outlet temperature (T3) of the reformed gas in real time. This temperature T3 is the most direct and key parameter reflecting the temperature level and reaction degree of the reaction zone. The T3 signal is transmitted to the external automatic heating control system in real time. S5.1 When T3 is lower than the set reaction temperature, such as 1260℃, the control system determines that the reaction heat demand has increased and then automatically starts one or more sets of electric heating tubes 106. The number of electric heating tubes started is proportionally or PID adjusted according to the deviation value between T3 and the set temperature to achieve precise and dynamic matching of heating power, thereby quickly and smoothly restoring the reaction temperature to the set value.

[0037] S5.2 When T3 reaches or exceeds the set temperature, the control system can reduce the number of operating groups or power of electric heating tubes accordingly, or even completely shut down electric heating, relying solely on burner 122 or the reaction's own thermal balance to maintain the temperature, thereby achieving energy-saving operation. Furthermore, through closed-loop control with real-time feedback of outlet temperature, the problem of temperature fluctuation in strongly endothermic reactions is effectively overcome, ensuring that the entire reaction process always takes place within the optimal and most stable temperature range, greatly improving the conversion rate and operational stability.

[0038] S6. After the temperature of the preheated feed gas is reduced, the reformed gas continues to flow through the shell-side flow channel 108 and finally exits the unit from the reformed gas outlet 104 and enters the downstream process. Thus, the feed gas has completed the entire process of deep preheating to high temperature non-catalytic reforming and finally product heat recovery for preheating.

[0039] S7. During the entire operation, the operator can monitor the data of the first temperature sensor 109 (T1), the second temperature sensor (T2), the third temperature sensor 111 (T3), and the flow meter (F) in real time through the control system. By analyzing the difference between T1 and T2, the heat exchange efficiency of the preheater can be evaluated. The stability of T3 can be used to judge the reaction control effect. Combined with the flow rate F, the material and energy balance of the system can be calculated, thereby enabling refined management and optimization of the entire unit's operating status.

[0040] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A combustible gas reforming preheater, comprising a reforming reactor shell (101) and a preheater shell (102), characterized in that: The reforming reactor cylinder (101) forms an inner cavity (121) inside, one end of which is connected to a burner (122) through a preheated raw material gas delivery pipe (113). The burner (122) is provided with a gas inlet (103). The other end of the reforming reactor shell (101) is connected to the preheater shell (102) through a hot reforming gas delivery pipe (114), and the preheater shell (102) is provided with a reforming gas outlet (104). The preheater shell (102) is provided with a heat exchange tube bundle (107). The inlet end of the heat exchange tube bundle (107) is connected to the gas inlet (103), and the outlet end is connected to the inner cavity (121) of the cylinder through the preheated raw material gas conveying pipe (113).

2. A combustible gas reforming preheater according to claim 1, characterized in that: The preheater shell (102) is also provided with a shell-side flow channel (108) surrounding the heat exchange tube bundle (107). The inlet of the shell-side flow channel (108) is connected to the hot reforming gas delivery pipe (114), and the outlet is connected to the reforming gas outlet (104).

3. A combustible gas reforming preheater according to claim 1, characterized in that: The reforming reactor shell (101) includes, from the outside to the inside, an outer protective plate (117), a heat insulation layer (116), and a fire-resistant insulation layer (115).

4. A combustible gas reforming preheater according to claim 1, characterized in that: Electric heating tubes (106) are arranged on the outer wall of the reforming reactor cylinder (101).

5. A combustible gas reforming preheater according to claim 3, characterized in that: It also includes a third temperature sensor (111) and an automatic heating control system; The third temperature sensor (111) is located on the hot reforming gas delivery pipe (114) at the connection point with the preheater shell (102); The third temperature sensor (111) is connected to the automatic heating control system, and the automatic heating control system is electrically connected to the electric heating tube (106).

6. A combustible gas reforming preheater according to claim 1, characterized in that: A first temperature sensor (109) is provided at the gas inlet (103); A preheating gas inlet (110) is installed at the connection position between the preheating raw material gas conveying pipe (113) and the reforming reactor shell (101), and a second temperature sensor is installed at one end of the preheating gas inlet (110).

7. A combustible gas reforming preheater according to claim 1, characterized in that: The burner (122) has an oxygen supply port (112) installed on one side, and a flow meter is installed at the port.

8. A combustible gas reforming preheater according to claim 1, characterized in that: The reforming reactor shell (101) is fixedly provided with a support base (119) at the bottom.

9. A combustible gas reforming preheater according to claim 1, characterized in that: No catalyst bed is provided in the inner cavity (121) of the cylinder.

10. A combustible gas reforming preheater according to claim 1, characterized in that: The preheater shell (102) is a rectangular shell, and its outer shell is the preheater insulation shell (118).

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