Self-circulation type saturated water heat extraction system

Abstract

This utility model discloses a self-circulating saturated water heat extraction system, which includes a reactor metal cylinder, a steam drum jacket outside the reactor metal cylinder, a steam drum heating rod inside the steam drum jacket, and a steam drum insulation on the outside. The steam drum jacket is filled with metal packing, and a packing pressure plate is located at the top of the steam drum jacket. The packing pressure plate has multiple small holes and multiple steam guide pipes. The top of the steam drum jacket is connected to the end cap at the bottom of the tube side of the steam condenser through a steam-condensate flow pipe. The end cap at the top of the tube side has a vent, a cooling water inlet is located at the bottom of the shell side, and a cooling water outlet is located at the top of the shell side. Because the steam drum contains saturated water, even a small increase in the reactor surface temperature will locally disrupt the temperature and pressure balance of the water, causing the water in contact with the reactor surface to vaporize. Simultaneously, since water vaporization requires the reactor wall to transfer heat equivalent to the latent heat of water vaporization, the system achieves the purpose of rapidly removing the heat released by the reaction.

Description

Technical Field

[0001] This utility model relates to a self-circulating saturated water vapor drum heat extraction system suitable for a single-tube reactor in an experimental device, belonging to the field of chemical heat exchange technology. Background Technology

[0002] The reactors in experimental setups typically operate isothermally. If the reaction is significantly exothermic, the catalyst must be diluted or the released heat must be rapidly removed to maintain a constant catalyst bed temperature within the reactor. Using circulating cooling water or molten salt for heat exchange involves transferring heat from a high-temperature medium to a low-temperature medium. Since this utilizes the sensible heat of the substance, the amount of heat exchange depends on the temperature difference between the hot and cold media, the heat exchange area, and the flow rate matching of the hot and cold media. This heat exchange method has many limitations, especially since the heat exchange area is limited by the reactor's outer surface area. Even with a large flow rate and low temperature of the cooling medium, the large amount of heat released in a short time may not be enough for heat exchange to maintain a constant reaction temperature. When the reaction temperature is not very high, or below the critical temperature of water (370°C), using the latent heat of vaporization of saturated water in contact with the reactor's outer wall to remove the reaction heat is an effective temperature control method. In industrial-scale strongly exothermic reactors, if a tubular reactor is used for saturated water vaporization heat extraction, due to the large amount of water vaporization, the vaporized steam must first be condensed into saturated water, which is then pumped back to the reactor's steam drum jacket by a condensate pump. For experimental reactors, while inert agents can be used to dilute the catalyst to maintain a constant reaction temperature, this requires a larger reactor size for the same catalyst loading, increasing manufacturing costs and installation space. If the catalyst is not diluted with an inert agent, the heat released by the vigorous reaction will rise sharply if not removed promptly. This not only fails to maintain a constant temperature, affecting the reaction efficiency, but can also lead to temperature runaway, causing equipment damage and personal injury. Therefore, for experimental reactors with highly exothermic reactions, it is essential to develop a simple and safe method for rapidly removing the released heat.

[0003] Because the catalyst loading and reactant flow rate of the experimental device are small, the vaporized steam, after condensing into saturated water, can be directly returned to the steam drum jacket for recirculation and heat extraction. This heat extraction method is simple, the reaction temperature is stably controlled, and it eliminates the need for a hot water circulation pumping system. The construction cost is low, and it avoids the potential for hot water leaks that could cause personal injury to users. Considering that the catalyst needs to be activated at high temperatures (above 370°C), the steam drum is filled with metal packing material. Heating rods pre-installed around the reactor heat the packing material, which then transfers the heat to the reactor to activate the catalyst. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a self-circulating saturated water vapor drum heat extraction system suitable for experimental devices.

[0005] To address the aforementioned problems, this utility model provides a self-circulating saturated water heat extraction system, comprising a reactor metal cylinder, a steam drum jacket outside the reactor metal cylinder, a steam drum heating rod inside the steam drum jacket, a steam drum insulation on the outside, a steam drum water inlet at the top, a steam drum water outlet at the bottom, metal packing inside the steam drum jacket, a packing pressure plate at the top of the steam drum jacket, and multiple small holes and multiple steam guide pipes on the packing pressure plate; the upper part of the steam drum jacket is connected to the end cap at the bottom of the tube side of the steam condenser through a steam-condensate flow pipe, the end cap at the top of the tube side of the steam condenser has an outlet, a cooling water inlet at the bottom of the shell side of the steam condenser, and a cooling water outlet at the top of the shell side of the steam condenser.

[0006] Preferably, the reactor metal cylinder is a reaction tube with an inner diameter of 22-50 mm, which facilitates the transfer of reaction heat.

[0007] Preferably, the steam drum jacket is equipped with a steam drum temperature measuring thermocouple, which is connected to the steam drum heating rod to form a control loop. This loop is used to heat the water to the saturation temperature during normal testing, and to heat the packing material and the catalyst in the reactor to the required activation temperature during catalyst activation.

[0008] Preferably, the stacking height of the metal packing is higher than the bed height of the catalyst inside the reactor's metal cylinder, so as to transfer the heat from the heating rod to the reactor during catalyst activation.

[0009] Preferably, the orifice includes an installation hole for installing a steam pipe and a steam flow hole for steam flow.

[0010] More preferably, the diameter of the steam flow hole is smaller than the particle size of the metal packing.

[0011] Preferably, the steam drum jacket is equipped with a steam drum level gauge with a scale. The steam drum level gauge is of differential pressure type and is connected to the gas phase at the top and the liquid phase at the bottom of the steam drum jacket, respectively, to determine the appropriate water level during water injection.

[0012] Preferably, the steam guide pipes are evenly arranged within the packing layer, with an inner diameter of 10-20 mm. The bottom of the longest steam guide pipe is 300-1000 mm above the lower outlet of the catalyst bed in the reactor, and the lengths of the other steam guide pipes are successively shortened by 300-500 mm to ensure that the gasified steam at different heights can be smoothly discharged. The bottom of the steam guide pipe is provided with 1-2 steel wires to prevent packing from entering the pipe. The number of steam guide pipes depends on the amount of gasified steam and the height of the catalyst bed.

[0013] Preferably, the steam condenser is a shell-and-tube water cooler, located above the top of the steam drum jacket, and can be installed vertically or at an angle. The steam condenser should be appropriately oversized to ensure sufficient steam condensation.

[0014] Preferably, the outlet of the tube side of the steam condenser is connected to a nitrogen pressure regulating system, which includes a nitrogen inlet pipe communicating with the outlet. A nitrogen pressure reducing valve and a steam drum back pressure valve are respectively installed on both sides of the nitrogen inlet pipe at the outlet connection point. A steam drum pressure gauge is installed between the nitrogen pressure reducing valve and the steam drum back pressure valve. The nitrogen pressure regulating system reduces the nitrogen pressure (which is higher than the required steam drum pressure) to slightly higher than the required steam drum pressure, and then the steam drum back pressure valve maintains the steam drum pressure at the target pressure, i.e., the saturation pressure of saturated water at the reaction temperature. Based on the test reaction temperature, i.e., the saturation pressure corresponding to the saturated water temperature, the nitrogen pressure regulating system pre-pressurizes the steam drum with nitrogen, and the pressure regulation system formed by the nitrogen pressure reducing valve and the back pressure valve stabilizes the jacket pressure at the required pressure.

[0015] In this invention, the heating rod heats the soft water in the jacket to the reaction temperature. The test material undergoes an exothermic reaction under the action of the catalyst, and the released heat causes the metal reactor wall to heat up rapidly. Since the steam drum is saturated with water, even a small increase in the reactor's outer surface temperature will locally disrupt the water's temperature and pressure balance, causing the water in contact with the reactor's outer surface to vaporize. Simultaneously, because water vaporization requires the reactor wall to transfer heat equivalent to the latent heat of water vaporization, the heat released by the reaction is quickly removed. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the steam drum self-circulating saturated water heat extraction system provided by this utility model. Detailed Implementation

[0017] To make this utility model more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings.

[0018] Example

[0019] like Figure 1 As shown, this utility model provides a self-circulating saturated water heat extraction system, which includes a reactor metal cylinder 1, wherein the reactor metal cylinder 1 adopts a reaction tube with an inner diameter of 22-50mm.

[0020] The reactor's metal cylinder 1 is surrounded by a steam drum jacket 2. Inside the steam drum jacket 2 are steam drum heating rods 3, and outside are steam drum insulation 9. A steam drum water inlet 11 is located at the top, and a steam drum water outlet valve 17 is located at the bottom. The steam drum jacket 2 contains metal packing 5, the stacking height of which is higher than the catalyst bed height inside the reactor's metal cylinder 1. The steam drum jacket 2 is equipped with a packing pressure plate 6, which has a number of small holes 18. These holes include mounting holes for installing steam pipes and steam flow holes for steam circulation. The diameter of the steam flow holes is slightly smaller than the particle size of the metal packing 5. A steam drum temperature measuring thermocouple 4 is installed inside the steam drum jacket 2, and it is connected to the steam drum heating rods 3 to form a control loop. The steam drum jacket 2 is equipped with a steam drum level gauge 10 with a scale. The steam drum level gauge 10 is a differential pressure type and is connected to the gas phase at the top and the liquid phase at the bottom of the steam drum jacket 2.

[0021] The number of steam guide pipes is determined by the intensity of the reaction, i.e., the amount of saturated water vaporization. The steam guide pipes are evenly distributed within the packing layer, with an inner diameter of 10-20 mm. The bottom of the longest steam guide pipe is 300-1000 mm above the lower outlet of the catalyst bed in the reactor, and the lengths of the other steam guide pipes decrease sequentially by 300-500 mm. Figure 1 Only the long steam pipe 7 and the short steam pipe 8 are shown in the diagram. Each steam pipe has 1-2 steel wires at the bottom to prevent packing from entering the pipe.

[0022] The top of the steam drum jacket 2 is connected to the end cap at the bottom of the tube side of the steam condenser 12 via a steam-condensate flow pipe 13. The end cap at the top of the tube side of the steam condenser 12 has an outlet, a cooling water inlet 19 at the bottom of the shell side, and a cooling water outlet 20 at the top of the shell side. The steam condenser 12 is a shell-and-tube water cooler located above the top of the steam drum jacket 2.

[0023] The outlet of the tube side of the steam condenser 12 is connected to a nitrogen pressure regulating system, which includes a nitrogen inlet pipe connected to the outlet. A nitrogen pressure reducing valve 14 and a steam drum back pressure valve 15 are respectively installed on both sides of the nitrogen inlet pipe at the outlet connection. A steam drum pressure gauge 16 is installed between the nitrogen pressure reducing valve 14 and the steam drum back pressure valve 15. The inlet end of the nitrogen pressure reducing valve 14 is connected to nitrogen, and the outlet end of the steam drum back pressure valve (15) is used for venting.

Claims

1. A self-circulating saturated water heat extraction system, characterized in that, The reactor includes a metal cylinder (1), a steam drum jacket (2) is provided outside the metal cylinder (1), a steam drum heating rod (3) is provided inside the steam drum jacket (2), a steam drum insulation (9) is provided outside, a steam drum water inlet (11) is provided at the top, a steam drum water outlet valve (17) is provided at the bottom, a metal packing (5) is installed inside the steam drum jacket (2), a packing pressure plate (6) is provided at the top of the steam drum jacket (2), and multiple small holes (18) and multiple steam pipes are opened on the packing pressure plate (6); the upper part of the steam drum jacket (2) is connected to the end cap at the bottom of the tube side of the steam condenser (12) through a steam-condensate flow pipe (13), the end cap at the top of the tube side of the steam condenser (12) is provided with an outlet, the lower part of the shell side of the steam condenser (12) is provided with a cooling water inlet (19), and the upper part of the shell side of the steam condenser (12) is provided with a cooling water outlet (20).

2. The self-circulating saturated water heat extraction system as described in claim 1, characterized in that, The reactor metal cylinder (1) is a reaction tube with an inner diameter of 22-50 mm.

3. The self-circulating saturated water heat extraction system as described in claim 1, characterized in that, The steam drum jacket (2) is equipped with a steam drum temperature measuring thermocouple (4), which is connected to the steam drum heating rod (3) to form a control loop.

4. The self-circulating saturated water heat extraction system as described in claim 1, characterized in that, The stacking height of the metal packing (5) is higher than the bed height of the catalyst inside the metal cylinder (1) of the reactor.

5. The self-circulating saturated water heat extraction system as described in claim 1, characterized in that, The small hole (18) includes an installation hole for installing a steam pipe and a steam flow hole for steam flow.

6. The self-circulating saturated water heat extraction system as described in claim 5, characterized in that, The diameter of the steam flow hole is smaller than the particle size of the metal packing (5).

7. The self-circulating saturated water heat extraction system as described in claim 1, characterized in that, The steam drum jacket (2) is equipped with a steam drum level gauge (10) with a scale. The steam drum level gauge (10) is of differential pressure type and is connected to the gas phase at the top and the liquid phase at the bottom of the steam drum jacket (2).

8. The self-circulating saturated water heat extraction system as described in claim 1, characterized in that, The steam guide pipes are evenly arranged in the packing layer, with an inner diameter of 10-20 mm. The bottom of the longest steam guide pipe is 300-1000 mm higher than the lower outlet of the catalyst bed in the reactor, and the lengths of the other steam guide pipes are successively shortened by 300-500 mm. The bottom of the steam guide pipe is provided with 1-2 steel wires to prevent the packing from entering the pipe.

9. The self-circulating saturated water heat extraction system as described in claim 1, characterized in that, The steam condenser (12) is a tubular water cooler located above the top of the steam drum jacket (2).

10. The self-circulating saturated water heat extraction system as described in claim 1, characterized in that, The outlet of the tube side of the steam condenser (12) is connected to a nitrogen pressure system, which includes a nitrogen pipe connected to the outlet. A nitrogen pressure reducing valve (14) and a steam drum back pressure valve (15) are respectively provided on both sides of the outlet connection on the nitrogen pipe. A steam drum pressure gauge (16) is provided between the nitrogen pressure reducing valve (14) and the steam drum back pressure valve (15).

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