Novel fire tube type high-pressure waste heat boiler

Abstract

The utility model discloses a novel fire tube type high-pressure waste heat boiler which comprises a front end tube box, a high-temperature section shell pass barrel, a middle tube box, a low-temperature section shell pass barrel, a rear end tube box, a high-temperature section heat exchange tube bundle arranged in the high-temperature section shell pass barrel and a low-temperature section heat exchange tube bundle arranged in the low-temperature section shell pass barrel. The inner center of the central tube penetrates from the front-end tube box to the rear-end tube box, and the central tube is directly communicated with the front-end tube box and the rear-end tube box; the front-end tube box is sequentially communicated with the high-temperature section heat exchange tube bundle, the middle tube box, the low-temperature section heat exchange tube bundle and the rear-end tube box; flexible tube plates are arranged at the two ends of the high-temperature section shell pass barrel and the two ends of the low-temperature section shell pass barrel, and reinforcing ribs are arranged on the front portion in the high-temperature section shell pass barrel and connected with the flexible tube plates. According to the fire tube type high-pressure waste heat boiler, the two-section type structure is adopted, meanwhile, the reinforcing rib flexible tube plate is arranged, the problem that the strength of the tube plate and the tube head is invalid under the high-temperature and high-pressure working conditions can be effectively solved, and meanwhile the problem that the structural stress is too large due to the fact that devices and equipment are large can be effectively solved.

Description

Technical Field

[0001] The utility model belongs to the field of chemical equipment, and particularly relates to a novel fire tube type high pressure waste heat boiler. Background Art

[0002] In the device for producing methanol and synthetic ammonia from natural gas, the temperature of the reformed gas from the reformer is as high as 800-1200℃ and the pressure is about 4Mpa. According to the process requirements, the temperature of the reformed gas needs to be cooled, and the waste heat is recovered to produce high-quality steam to provide power for the subsequent turbine units.

[0003] As the size of the equipment increases, the size of the equipment also increases. The existing waste heat boiler structure is difficult to meet the requirements of process performance. Due to the high temperature and pressure of the reformed gas, the waste heat boiler with a traditional thick tube sheet structure will cause high tube sheet stress and the risk of cracking of the tube head weld.

[0004] The currently widely used flexible tube sheet waste heat boiler can only be used when the device is of moderate scale and under good working conditions. When the device is large, the temperature difference stress between the heat exchange tube and the tube sheet will be very high, and the ordinary flexible tube sheet structure cannot reduce the tube sheet stress to a safe level. In addition, when the load of the device fluctuates, the medium temperature at the outlet of the waste heat boiler will also fluctuate greatly, which brings great safety risks to the operation of subsequent equipment of the device. Utility Model Content

[0005] The purpose of the utility model is to address the defects of the prior art and provide a two-stage reinforced rib flexible tube sheet waste heat boiler that can operate stably under high temperature and high pressure conditions, and at the same time has the function of adjustable outlet medium temperature, which can meet the needs of large-scale devices and equipment.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a novel fire tube type high-pressure waste heat boiler, comprising: a front end pipe box, a high temperature section shell side cylinder, an intermediate pipe box, a low temperature section shell side cylinder and a rear end pipe box connected in sequence, a high temperature section heat exchange tube bundle arranged in the high temperature section shell side cylinder, a low temperature section heat exchange tube bundle arranged in the low temperature section shell side cylinder, and a central pipe running from the front end pipe box to the rear end pipe box and directly connecting the front end and rear end pipe boxes;

[0007] The front-end pipe box is connected in sequence to the high-temperature section heat exchange tube bundle, the middle pipe box, the low-temperature section heat exchange tube bundle and the rear-end pipe box;

[0008] Both ends of the high temperature section shell cylinder and the low temperature section shell cylinder are flexible tube sheets, and reinforcing ribs are arranged at the front of the high temperature section shell cylinder, and the reinforcing ribs are connected to the flexible tube sheets.

[0009] Furthermore, a gas inlet is arranged on the side of the front end pipe box, and a gas distributor is arranged below the gas inlet.

[0010] Furthermore, a gas outlet is provided at the end of the rear end pipe box.

[0011] Furthermore, the shell side of the high temperature section shell side cylinder and the low temperature section shell side cylinder are both provided with a liquid inlet and an outlet.

[0012] Furthermore, the front end of the central tube is welded to the flexible tube plate at the front end of the high temperature section shell cylinder, an expansion joint is arranged at the middle tube box, and a regulating valve is arranged at the rear end of the rear end tube box.

[0013] Furthermore, the reinforcing ribs are welded inside the high temperature section shell cylinder and connected to the flexible tube sheet by welding.

[0014] Furthermore, the front end tube box, flexible tube sheet, high temperature section shell cylinder, and high temperature section heat exchange tube bundle are connected by welding, and the rear end tube box, tube sheet, low temperature section shell cylinder, and low temperature section heat exchange tube bundle are connected by welding.

[0015] The utility model is a new type of fire tube high-pressure waste heat boiler, which adopts a two-stage structure and is provided with a reinforcing rib flexible tube sheet, which can effectively solve the problem of tube sheet and tube head strength failure under high temperature and high pressure conditions, and can also effectively solve the problem of excessive structural stress caused by large-scale devices and equipment. In addition, a central tube is provided on the flexible tube sheet, and a regulating valve is provided at the end of the central tube to adjust the flow of high-temperature medium entering the rear end pipe box, thereby realizing the function of regulating the medium temperature at the outlet of the waste heat boiler. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a novel fire tube waste heat boiler device according to an embodiment.

[0017] Figure 2 Schematic diagram of the connection between the reinforcing rib and the flexible tube sheet in the embodiment. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.

[0019] It should be noted that the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatuses.

[0020] like Figure 1 As shown, the new fire tube high-pressure waste heat boiler consists of a front end pipe box 1, a gas distributor 2, a flexible tube sheet 3, a high temperature section heat exchange tube bundle 4, a high temperature section shell cylinder 5, an intermediate pipe box 6, a center pipe 7, an expansion joint 8, a low temperature section heat exchange tube bundle 9, a low temperature section shell cylinder 10, a regulating valve 11, a rear end pipe box 12, and a reinforcing rib 13.

[0021] The front-end tube box 1, the flexible tube sheet 3, the high-temperature section shell-side cylinder 5, and the high-temperature section heat exchange tube bundle 4 are connected by welding, and the reinforcing ribs 13 are welded to the flexible tube sheet 3. The rear-end tube box 12, the tube sheet 3, the low-temperature section shell-side cylinder 10, and the low-temperature section heat exchange tube bundle 9 are connected by welding. In the front-end tube box 1, the gas inlet is arranged radially, and a gas distributor 2 is provided at the inlet to ensure the uniformity of the gas entering each heat exchange tube. The central tube 7 runs from the front-end tube box 1 to the rear-end tube box 12, and is welded to the flexible tube sheet 3 respectively. An expansion joint 8 is provided at the intermediate tube box to reduce the temperature difference stress of the central tube. At the same time, a regulating valve 11 is provided at the end of the central tube of the rear-end tube box to adjust the flow of high-temperature gas from the front-end tube box through the central tube, so as to achieve the purpose of adjusting the temperature of the gas medium in the rear-end tube box.

[0022] The new fire tube high pressure waste heat boiler adopts a two-stage structural design: the first section is the high temperature heat exchange section, and the high temperature section heat exchange tube bundle 4 and the high temperature section shell side cylinder 5, and the second section is the low temperature heat exchange section, and the low temperature section heat exchange tube bundle 9 and the high temperature section shell side cylinder 10. The high temperature conversion gas is evenly distributed through the front end pipe box 1 and the gas distributor 2 and enters the high temperature section heat exchange tube bundle 4, heating the water inside the high temperature section shell side cylinder 5, making the water boil and produce high pressure saturated steam. After the temperature of the high temperature conversion gas is reduced through the first section of heat exchange, it enters the low temperature section heat exchange tube bundle 9 through the intermediate pipe box 6, heats the water inside the low temperature section shell side cylinder 10, and produces high pressure saturated steam. The conversion gas finally enters the next process flow from the outlet of the rear end pipe box 12.

[0023] The central tube 7 passes through the front tube box 1, the high temperature section shell cylinder 5, the intermediate tube box 6, and the low temperature section shell cylinder 10 to reach the rear tube box 12. Part of the high temperature conversion gas can directly reach the rear tube box 12 from the central tube 7 to mix with the conversion gas after heat exchange. The flow rate of the high temperature conversion gas in the central tube 7 is adjusted by the regulating valve 11 to adjust the temperature of the final mixed conversion gas. The central tube 7 is provided with an expansion joint 8 at the intermediate tube box 6 to absorb the thermal expansion difference of the central tube and ensure the safety and reliability of the central tube 7.

[0024] like Figure 2 As shown, the reinforcing ribs 13 are welded to the high-temperature section tube sheet 3 and the high-temperature section cylinder 10 at the same time, which effectively strengthens the flexible tube sheet and reduces the tube sheet stress, and is a key technology for realizing large-scale devices and equipment.

[0025] The above is a further detailed description of the utility model, which should not be regarded as a limitation on the specific implementation of the utility model. For ordinary technicians in the technical field to which the utility model belongs, simple deduction or replacement without departing from the concept of the utility model is within the protection scope of the utility model.

Claims

1. A new type of fire tube high pressure waste heat boiler, characterized in that include: The front pipe box, high temperature section shell cylinder, intermediate pipe box, low temperature section shell cylinder and rear pipe box connected in sequence, the high temperature section heat exchange tube bundle arranged in the high temperature section shell cylinder, the low temperature section heat exchange tube bundle arranged in the low temperature section shell cylinder, and the central pipe running from the front pipe box to the rear pipe box and directly connecting the front and rear pipe boxes; The front-end pipe box is connected in sequence to the high-temperature section heat exchange tube bundle, the middle pipe box, the low-temperature section heat exchange tube bundle and the rear-end pipe box; Both ends of the high temperature section shell cylinder and the low temperature section shell cylinder are flexible tube sheets, and reinforcing ribs are arranged at the front of the high temperature section shell cylinder, and the reinforcing ribs are connected to the flexible tube sheets.

2. The novel fire tube high pressure waste heat boiler according to claim 1 is characterized in that: The front end pipe box is provided with a gas inlet at the side, and a gas distributor is provided below the gas inlet.

3. The novel fire tube high pressure waste heat boiler according to claim 1 is characterized in that: A gas outlet is provided at the end of the rear end pipe box.

4. The novel fire tube high pressure waste heat boiler according to claim 1 is characterized in that: The shell sides of the high-temperature section shell side cylinder and the low-temperature section shell side cylinder are both provided with a liquid inlet and an outlet.

5. The novel fire tube high pressure waste heat boiler according to claim 1 is characterized in that: The front end of the central tube is welded to the flexible tube plate at the front end of the high temperature section shell cylinder, an expansion joint is arranged at the middle tube box, and a regulating valve is arranged at the rear end of the rear end tube box.

6. The novel fire tube high pressure waste heat boiler according to claim 1 is characterized in that: The reinforcing ribs are welded inside the high temperature section shell cylinder and connected to the flexible tube sheet by welding.

7. The novel fire tube high pressure waste heat boiler according to claim 1 is characterized in that: The front end tube box, flexible tube sheet, high temperature section shell cylinder, and high temperature section heat exchange tube bundle are connected by welding, and the rear end tube box, tube sheet, low temperature section shell cylinder, and low temperature section heat exchange tube bundle are connected by welding.

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