Water bath vaporizer

Abstract

The utility model belongs to the technical field of gasifiers, and particularly relates to a water bath gasifier which comprises a tank body, a liquefied natural gas pipeline arranged in the tank body, a circulating water inlet arranged below the tank body and a circulating water outlet arranged above the tank body, comprising a root pipeline and at least two stages of branch pipelines, every two adjacent stages of branch pipelines comprise upper-stage pipelines and lower-stage pipelines, the number of the lower-stage pipelines is larger than that of the upper-stage pipelines, the lower-stage pipelines are formed by forking the upper-stage pipelines, and the diameter of a single upper-stage pipeline is larger than that of a single lower-stage pipeline. Liquefied natural gas enters the thicker root pipeline, circulating water flowing in from the lower part of the tank body quickly flows through the root pipeline, then enters the next-stage branch pipeline and finally enters the final-stage pipeline, the liquefied natural gas is gasified into gaseous natural gas, and the flowing speed of the circulating water is slowed down along with the increase of the contact area of the pipelines and the volume of the tank body, so that the heat exchange time is prolonged; the heat exchange efficiency is improved.

Description

Technical Field

[0001] The utility model relates to a water bath gasifier, belonging to the technical field of gasifiers. Background Art

[0002] Natural gas is a naturally occurring fuel, the main component of which is methane. It is a clean and efficient energy source, widely used in industries, households, and commerce. Natural gas is liquefied at ultra-low temperatures to form liquefied natural gas (LNG), with a boiling point of about -162°C. Compared with gaseous natural gas, liquefied natural gas has a higher energy density, and the volume of liquefied natural gas is about 1 / 600 of that of gaseous natural gas, making it easier to transport to areas without natural gas pipelines.

[0003] A water bath vaporizer is a device that vaporizes liquefied natural gas into gaseous natural gas by exchanging heat between hot water and liquefied natural gas. Existing water bath vaporizers generally require water to be heated to a certain temperature first to vaporize liquefied natural gas, and the cooled water needs to be heated again to vaporize natural gas. Repeated cycles of heating water waste heat energy and fail to make good use of resources.

[0004] At the same time, various units at industrial sites will generate heat during operation. In order to ensure the normal operation of the units, circulating cooling water is generally used to cool the units. The cooling water that absorbs the heat of the units adopts the traditional cooling tower cooling method, that is, the hotter cooling water is pumped from the industrial equipment into the cooling tower, and the temperature of the cooling water is reduced by heat exchange with the air. However, the evaporation of water during the cooling process of the cooling tower will cause the loss of cooling water. At the same time, the cooling tower is an open heat dissipation, and there are also various impurities entering the cooling water. Therefore, there is a scheme that uses the cooling water at the industrial site to exchange heat with liquid natural gas, which not only realizes the cooling of the cooling water, but also realizes the gasification of the liquid natural gas, killing two birds with one stone. However, due to the limited temperature of the cooling water, even in summer, the temperature of the cooling water after fully absorbing the heat of the unit generally does not exceed 40 degrees, while the temperature of the liquid natural gas is -162℃. Therefore, when using cooling water and liquid natural gas for heat exchange, poor control may cause the cooling water to freeze, thereby affecting the supply of cooling water and natural gas, and seriously affecting the safe and stable operation of the site. Utility Model Content

[0005] The purpose of the utility model is to provide a new technical solution to improve or solve the technical problems existing in the prior art as described above.

[0006] The technical solution provided by the utility model is as follows: a water bath gasifier, comprising a tank body, a liquefied natural gas pipeline is arranged in the tank body, a circulating water inlet is arranged at the bottom of the tank body, and a circulating water outlet is arranged at the top of the tank body. The liquefied natural gas pipeline enters from the bottom and exits from the top. The liquefied natural gas pipeline has a tree-like structure, including a root pipeline and at least two levels of branch pipelines. The adjacent two levels of branch pipelines include an upper pipeline and a lower pipeline. The number of the lower pipelines is greater than the number of the upper pipelines. The lower pipeline is branched from the upper pipeline, and the diameter of a single upper pipeline is greater than the diameter of a single lower pipeline.

[0007] Compared with the prior art, the technical solution provided by the utility model has the following beneficial effects: liquid natural gas enters a relatively thick root pipe. Since there is only one root pipe, its area participating in heat exchange is limited. The circulating water flowing in from the bottom of the tank body quickly flows through the root pipe and the time participating in heat exchange is limited, thereby avoiding the situation where the cooling water is overcooled to ice. The gas-liquid mixed natural gas whose temperature has been raised to a certain level continues to enter the next-level branch pipe. The area participating in heat exchange in the next-level branch pipe is larger than the root pipe, and the time participating in heat exchange of the circulating water will be longer. However, since the gas-liquid mixed natural gas participates in heat exchange at this time, the heat exchange amount is lower than that of pure liquid natural gas. Therefore, the time participating in heat exchange of the circulating water is well controlled, and even if it is longer than the heat exchange time at the root pipe, it can be ensured that the circulating water does not freeze. By analogy, until the final-stage pipe, the liquid natural gas is basically converted into gaseous natural gas, and its volume expands to hundreds of times that of the liquid natural gas. Therefore, at the final-stage pipe, the amount of natural gas participating in heat exchange under the same volume is much smaller than the amount participating in heat exchange at the root pipe. Therefore, the flow rate of the circulating water can be further slowed down, and the heat exchange time can be increased.

[0008] On the basis of the above technical solution, the present invention can also be improved as follows.

[0009] Furthermore, the lower-level pipeline is branched from the upper-level pipeline, and the number of branches is at least two.

[0010] The beneficial effect of adopting the above further solution is that the pipelines are bifurcated into multiple pipelines, thereby ensuring sufficient heat exchange area for the circulation of natural gas and making full use of the space in the tank.

[0011] Furthermore, the last branch pipeline is called the final pipeline, and the outer surface of the final pipeline is provided with fins for increasing the heat exchange area; adding fins to the final pipeline increases the heat exchange area to further improve the heat exchange effect, ensuring that the temperature of the natural gas is raised to room temperature, while ensuring that the circulating water does not freeze into ice.

[0012] Furthermore, the liquefied natural gas enters from the root pipeline and is discharged from the final pipeline in the gaseous state, and the diameter of the single pipeline gradually decreases along the flow direction of the natural gas.

[0013] The beneficial effect of adopting the above further scheme is that the liquid is at the bottom and the gas is at the top, which is convenient for exhaust. The smaller the pipe diameter, the larger the area involved in heat exchange. The diameter of a single pipe gradually decreases along the flow direction of natural gas, which means that the heat exchange area gradually increases along the flow direction of natural gas, thereby improving the heat exchange efficiency while ensuring that the circulating water does not freeze.

[0014] Furthermore, the tank body is wide at the top and narrow at the bottom. The space formed between the tank body and the outer wall of the internal natural gas pipeline is the channel for circulating water. The wide top and narrow bottom force the circulating water to flow at a faster speed at the bottom and at a slower speed at the top, so as to ensure that it will not be overcooled and frozen when exchanging heat with liquid natural gas at the bottom, and that it has sufficient time to participate in heat exchange when exchanging heat with gaseous natural gas at the top, thereby ensuring the gasification and cooling effects.

[0015] Furthermore, the final stage pipelines are distributed in a spiral ascending shape.

[0016] The beneficial effect of adopting the above further solution is that the spiral rise increases the area involved in heat exchange, reduces the height of the tank body, and reduces production costs.

[0017] Furthermore, an electric control valve is provided at the front end of the root pipe, an inlet water temperature sensor is provided at the circulating water inlet, an outlet water temperature sensor is provided at the circulating water outlet, and a natural gas outlet temperature sensor is provided at the outlet of the final pipe. The heat exchange condition is judged by observing the inlet water temperature, outlet water temperature and natural gas outlet temperature. If the natural gas outlet temperature is lower than 8°C, it means that the circulating water heat supply is insufficient and there is a risk of the circulating water being frozen. An alarm message is promptly sent out, and the operator adjusts the amount of natural gas supplied to the water bath vaporizer by adjusting the electric control valve at the root pipe. If the natural gas outlet temperature is lower than 3°C, a shutdown signal is promptly sent to cut off the electric control valve at the root pipe to avoid internal freezing and affect the water and gas use on site. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the utility model;

[0019] Figure 2 It is a schematic diagram of the overall structure of the liquefied natural gas pipeline;

[0020] Figure 3 This is a schematic diagram of the cross-sectional structure of the final stage pipe and fins.

[0021] In the figure, 1. tank body; 2. liquid natural gas pipeline; 3. circulating water inlet; 4. circulating water outlet; 5. root pipe; 6. branch pipe; 7. final stage pipe; 8. fin. DETAILED DESCRIPTION

[0022] The principles and features of the present invention are described below in conjunction with examples. The examples are only used to explain the present invention and are not used to limit the scope of the present invention.

[0023] Example 1

[0024] like Figure 1-Figure 3 As shown, a water bath vaporizer comprises a tank body 1, wherein a liquefied natural gas pipeline 2 is arranged in the tank body 1, a circulating water inlet 3 is arranged below the tank body 1, and a circulating water outlet 4 is arranged above the tank body 1, wherein the liquefied natural gas pipeline 2 enters from the bottom and exits from the top, and the liquefied natural gas pipeline 2 is in a tree-like structure, comprising a root pipe 5 and at least two-stage branch pipes 6, wherein the adjacent two-stage branch pipes 6 comprise an upper-stage pipe and a lower-stage pipe, wherein the number of the lower-stage pipes is greater than the number of the upper-stage pipes, wherein the lower-stage pipes are forked from the upper-stage pipes, wherein the number of forks is at least two, and the diameter of a single upper-stage pipe is greater than the diameter of a single lower-stage pipe; wherein the last-stage branch pipe 6 is called a final-stage pipe 7, wherein the outer surface of the final-stage pipe 7 is provided with fins 8 for increasing the heat exchange area, thereby increasing the area involved in the heat exchange, reducing the height of the tank body 1, and reducing the production cost. The liquefied natural gas enters from the root pipe 5, and the gaseous natural gas is discharged from the final-stage pipe 7, and the diameter of the single root pipe 5 gradually decreases along the flow direction of the natural gas.

[0025] An electric control valve is provided at the front end of the root pipe 5, an inlet water temperature sensor is provided at the circulating water inlet, an outlet water temperature sensor is provided at the circulating water outlet, and a natural gas outlet temperature sensor is also provided at the outlet of the final-stage pipe 7.

[0026] The circulating water flow data, gaseous natural gas flow data, and the temperature data of the inlet water temperature sensor, outlet water temperature sensor, and natural gas outlet temperature sensor are measured, as shown in Table 1.

[0027] Table 1 Circulating water and gaseous natural gas flow and temperature measurement data

[0028]

[0029]

[0030] Example 2

[0031] like Figure 1 As shown, on the basis of Example 1, the tank body 1 is in a shape that is wide at the top and narrow at the bottom. The space formed between the tank body 1 and the outer wall of the internal natural gas pipeline is the channel for circulating water. The shape is wide at the top and narrow at the bottom, forcing the circulating water to flow at a faster speed at the bottom and flow at a slower speed at the top, so as to ensure that the circulating water will not be overcooled and frozen when exchanging heat with the liquid natural gas at the bottom, and has sufficient time to participate in the heat exchange when exchanging heat with the gaseous natural gas at the top, thereby ensuring the gasification and cooling effects.

[0032] Example 3

[0033] On the basis of Example 1, other structures remain unchanged, and the vertical final-stage pipe 7 and the fin 8 structure added to the outer surface are changed to a final-stage pipe 7 distributed in a spiral ascending shape, thereby increasing the area involved in heat exchange, reducing the height of the tank body 1, and reducing production costs.

[0034] How this application works:

[0035] The water bath vaporizer uses the hotter cooling water from the industrial site unit to exchange heat with the liquid natural gas, so that the natural gas is heated and gasified, and the cooling water is cooled. The cooled cooling water flows back to the industrial site unit again to cool the equipment. The inlet water temperature sensor and the outlet water temperature sensor are used to monitor the temperature of the cooling water. The outlet of the final pipeline 7 is provided with a natural gas outlet temperature sensor to detect the temperature of the natural gas to avoid excessive cooling that causes the cooling water to freeze and affect the use of water and gas on site. The liquid natural gas pipeline 2 in the vaporizer tank 1 is in a tree structure, and the heat exchange area is gradually increased by increasing the number of pipelines and reducing the diameter of the pipelines in stages.

[0036] This method makes full use of the cooling capacity of the liquefied natural gas. At the same time, by controlling the flow of circulating water and liquefied natural gas input and the heat exchange time, the liquefied natural gas is completely converted into gaseous natural gas when it reaches the final pipeline 7, thereby improving the heat exchange efficiency.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A water bath vaporizer, comprising a tank body (1), characterized in that: A liquefied natural gas pipeline (2) is arranged in the tank body (1), a circulating water inlet (3) is arranged at the bottom of the tank body (1), and a circulating water outlet (4) is arranged at the top of the tank body (1), the liquefied natural gas pipeline (2) enters from the bottom and exits from the top, the liquefied natural gas pipeline (2) is in a tree-like structure, comprising a root pipeline (5) and at least two levels of branch pipelines (6), the adjacent two levels of branch pipelines (6) comprising an upper pipeline and a lower pipeline, the number of the lower pipelines is greater than the number of the upper pipelines, the lower pipelines are branched from the upper pipelines, and the diameter of a single upper pipeline is greater than the diameter of a single lower pipeline.

2. The water bath vaporizer according to claim 1, characterized in that: The lower-level pipeline is branched from the upper-level pipeline, and the number of branches is at least two.

3. The water bath vaporizer according to claim 2, characterized in that: The last branch pipe (6) is called the final pipe (7), and the outer surface of the final pipe (7) is provided with fins (8) for increasing the heat exchange area.

4. The water bath vaporizer according to claim 3, characterized in that: The liquefied natural gas enters from the root pipeline (5) and is discharged from the final pipeline (7). The diameter of the single pipeline (5) gradually decreases along the flow direction of the natural gas.

5. The water bath vaporizer according to claim 1, characterized in that: The tank body (1) is in a shape that is wide at the top and narrow at the bottom.

6. The water bath vaporizer according to claim 2, characterized in that: The final stage pipeline (7) is distributed in a spiral ascending shape.

7. The water bath vaporizer according to claim 6, characterized in that: An electric control valve is provided at the front end of the root pipeline (5), an inlet water temperature sensor is provided at the circulating water inlet, an outlet water temperature sensor is provided at the circulating water outlet, and a natural gas outlet temperature sensor is also provided at the outlet of the final pipeline (7).

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