System for preparing acetylene by partially oxidizing natural gas

Abstract

The invention discloses a system for preparing acetylene by partial oxidation of natural gas, which comprises a heating furnace for preheating raw materials and a steam using unit, the heating furnace is provided with an air inlet for combustion-supporting air to enter, the steam using unit is provided with a steam condensate discharge pipe, and the steam condensate discharge pipe is provided with a steam condensate outlet. The air inlet is connected with a heat exchanger communicated with the steam condensate discharge pipe, and the heat exchanger is provided with an air channel communicated with the air inlet. According to the scheme, the problem of high energy consumption of the system in the prior art is solved.

Description

Technical Field

[0001] The present invention relates to an acetylene preparation device, specifically a system for the partial oxidation of natural gas to acetylene. Background Art

[0002] A system for the partial oxidation of natural gas to acetylene is a system that uses natural gas and oxygen as raw materials. The raw materials are first heated in a preheating furnace and then enter a cracking furnace, where the natural gas is oxidized and cracked to obtain acetylene.

[0003] Chinese patent document CN110872205A discloses a device for the partial oxidation of natural gas to acetylene, including an oxygen preheating furnace, a natural gas preheating furnace, an acetylene furnace, a cooling tower, a flare, an electrostatic precipitator (electrofilter), a vacuum stripping tower, a heat exchanger, a gas-liquid separation tank, an open carbon black separation tank, and a hyperbolic cooling tower, etc. After the oxygen enters the preheating furnace and is heated, it enters the acetylene furnace together with the natural gas that has entered the preheating furnace for a partial oxidation reaction. After being quenched by the cooled carbon black water provided by the heat exchanger, a cracked gas containing acetylene is obtained.

[0004] With the increasing requirement of reducing energy consumption, how to reduce the energy consumption of the system for the partial oxidation of natural gas to acetylene has become an urgent problem to be solved. Summary of the Invention

[0005] The purpose of the present invention is to provide a system for the partial oxidation of natural gas to acetylene to solve the problem of relatively high energy consumption of the existing system.

[0006] To achieve the above purpose, the basic scheme of the present invention provides a system for the partial oxidation of natural gas to acetylene, including a heating furnace for preheating raw materials. The heating furnace is provided with an air inlet for the entry of combustion-supporting air, and also includes a steam using unit. The steam using unit is provided with a steam condensate discharge pipe. A heat exchanger communicating with the steam condensate discharge pipe is connected at the air inlet. The heat exchanger has an air passage communicating with the air inlet.

[0007] The principle and beneficial effects of this basic scheme are as follows: With such a setting, the steam condensate formed after the steam using unit uses steam is discharged from the steam condensate discharge pipe and flows through the heat exchanger. At this time, the steam condensate has a relatively high temperature, and the steam condensate heats the air passage of the heat exchanger through the heat exchanger, so that the air entering the air passage from the outside is heated before entering the air inlet. Compared with the prior art, the fuel gas consumption of the heating furnace in the system decreases by 1 - 3 m³ per hour, significantly reducing the energy consumption.

[0008] Further, the heat exchanger includes finned tubes through which steam condensate flows and transfers heat to the air passage of the heat exchanger. With such an arrangement, the heat transfer efficiency of the finned tubes is high, which is conducive to further enhancing the heating effect of the steam condensate on the combustion-supporting air, thereby further reducing the fuel gas consumption of the heating furnace and further reducing the energy consumption.

[0009] Further, the air passage includes a horizontal passage and a vertical passage. One end of the horizontal passage is communicated with the air inlet, the other end of the horizontal passage is communicated with the upper end of the vertical passage, and the inlet of the air passage is located at the lower end of the vertical passage. With such an arrangement, when there is a strong wind outside the heating furnace, the influence on the flame of the heating furnace burner is avoided, which is conducive to ensuring the heating stability of the heating furnace.

[0010] Further, it further includes a condensate cooler for cooling the steam condensate, and the heat exchanger is located between the condensate cooler and the steam using unit. With such an arrangement, it is conducive to reducing the energy consumption of the steam cooler for cooling the steam condensate while reducing the energy consumption of the heating furnace, thereby further reducing the energy consumption of the entire system.

[0011] Further, the condensate cooler is a circulating water cooler. The heat of the steam condensate is taken away by the circulating flow of cooling water, thereby realizing further cooling of the steam condensate. Through the combined use of the heat exchanger and the condensate cooler, the amount of circulating water used by the condensate cooler for cooling the steam condensate is greatly reduced, which is conducive to reducing the consumption of system circulating water.

[0012] Further, the steam using unit is an electrostatic filter. The electrostatic filter is generally arranged at a position relatively close to the heating furnace, so that the steam condensate discharged from the electrostatic filter can quickly enter the heat exchanger, and the temperature of the steam condensate can be transferred to the air passage in the heat exchanger as much as possible, thereby improving the heating effect on the combustion-supporting air, and there is no need to add a new pump device for transportation, achieving the effect of both reducing energy consumption and reducing the equipment improvement cost.

[0013] Further, the finned tubes are arranged in the vertical passage of the air passage. With such an arrangement, it is conducive to improving the heating effect of the heat exchanger on the combustion-supporting air, thereby further reducing the energy consumption. Description of the Drawings

[0014] Figure 1 is a schematic diagram of Embodiment 1 of a system for partial oxidation of natural gas to acetylene according to the present invention; Figure 2 is a schematic diagram of Embodiment 2 of a system for partial oxidation of natural gas to acetylene according to the present invention. Detailed Embodiments

[0015] The following is a further detailed description through specific embodiments: The reference numerals in the accompanying drawings of the specification include: heating furnace 1, air inlet 11, horizontal channel 21, vertical channel 22, inlet 23, finned tube 24, steam utilization unit 3, steam condensate discharge pipe 4, condensate cooler 5, liquid storage tank 6, and pump 7.

[0016] Example 1: Basically as shown in the attached Figure 1 As shown, a system for the partial oxidation of natural gas to acetylene includes a heating furnace 1 for preheating the raw materials. The heating furnace 1 is provided with an air inlet 11 for the entry of combustion-supporting air. A heat exchanger is connected to the air inlet 11, and the heat exchanger has an air channel communicating with the air inlet 11. In this embodiment, the air channel of the heat exchanger includes a horizontal channel 21 and a vertical channel 22. One end of the horizontal channel 21 communicates with the air inlet 11, the other end of the horizontal channel 21 communicates with the upper end of the vertical channel 22, and the inlet 23 of the air channel is located at the lower end of the vertical channel 22. Thus, the combustion-supporting air first enters the vertical channel 22 from the inlet 23 at the lower end of the vertical channel 22, then passes through the vertical channel 22 and then enters the horizontal channel 21, and finally enters the air inlet 11 of the heating furnace 1. The heat exchanger further includes finned tubes 24, and the finned tubes 24 are located in the air channel. Specifically, the finned tubes 24 are arranged in the vertical channel 22.

[0017] This system further includes a steam utilization unit 3 provided with a steam condensate discharge pipe 4. In this embodiment, the steam utilization unit 3 can be an electrostatic filter. Of course, in other embodiments, the steam utilization unit 3 can also be other devices that utilize steam. The steam condensate discharge pipe 4 communicates with the finned tubes 24 of the heat exchanger, so that the steam condensate generated by the steam utilization unit 3 will flow through the finned tubes 24 after being discharged, thereby realizing the transfer of the heat of the steam condensate to the air channel of the heat exchanger, so as to heat the combustion-supporting air in the air channel.

[0018] This system further includes a condensate cooler 5 for cooling the steam condensate. The heat exchanger is located between the condensate cooler 5 and the steam utilization unit 3, so that the steam condensate is cooled down by the condensate cooler 5 after flowing out of the heat exchanger. In this embodiment, the condensate cooler 5 is preferably a circulating water cooler. After the steam condensate flows out of the condensate cooler 5, it is collected in the liquid storage tank 6 and finally transported to each condensate user unit through the pump 7.

[0019] The specific implementation process is as follows: When the system is in use, the combustion-supporting air enters the vertical channel 22 from the inlet 23 at the lower end of the vertical channel 22 of the heat exchanger (the flow direction of the combustion-supporting air is shown by the dotted arrow in the figure). The steam condensate discharged from the steam utilization unit 3 flows through the steam condensate discharge pipe 4 into the finned tube 24 of the heat exchanger (the flow direction of the steam condensate is shown by the solid arrow in the figure). The heat of the steam condensate is transferred to the combustion-supporting air in the vertical channel 22 through the finned tube 24, thereby increasing the temperature of the combustion-supporting air. Then, the combustion-supporting air enters the air inlet 11 of the heating furnace 1 through the horizontal channel 21. Through trial use, it is found that the fuel gas consumption of the heating furnace 1 is reduced by 1 - 3 m³ per hour, significantly reducing the energy consumption.

[0020] Embodiment 2: The difference from Embodiment 1 is that, as Figure 2 shown, the finned tube 24 of the heat exchanger is directly connected to the liquid storage tank 6, and there is no need to set up a condensate cooler 5 to cool the steam condensate again, thereby simplifying the equipment and saving the equipment cost and operation cost.

[0021] The above are only the embodiments of the present invention. Common knowledge such as the specific structures and characteristics in the solutions is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the structure of the present invention, several deformations and improvements can still be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent.

Claims

1. A system for the partial oxidation of natural gas to acetylene, comprising a heating furnace for preheating the raw materials, the heating furnace being provided with an air inlet for the combustion-supporting air to enter, and further comprising a steam usage unit, the steam usage unit being provided with a steam condensate discharge pipe. Characterized in that: A heat exchanger connected to the air inlet and communicating with the steam condensate discharge pipe is provided at the air inlet, and the heat exchanger has an air passage communicating with the air inlet.

2. A system for the partial oxidation of natural gas to acetylene according to claim 1, Characterized in that: The heat exchanger includes finned tubes through which the steam condensate flows and transfers heat to the air passage of the heat exchanger.

3. A system for the partial oxidation of natural gas to acetylene according to claim 2, Characterized in that: The air passage includes a horizontal passage and a vertical passage. One end of the horizontal passage communicates with the air inlet, the other end of the horizontal passage communicates with the upper end of the vertical passage, and the inlet of the air passage is located at the lower end of the vertical passage.

4. A system for the partial oxidation of natural gas to acetylene according to any one of claims 1 to 3, Characterized in that: It further includes a condensate cooler for cooling the steam condensate, and the heat exchanger is located between the condensate cooler and the steam usage unit.

5. A system for the partial oxidation of natural gas to acetylene according to claim 4, Characterized in that: The condensate cooler is a circulating water cooler.

6. A system for the partial oxidation of natural gas to acetylene according to claim 5, Characterized in that: The steam usage unit is an electrostatic filter.

7. A system for the partial oxidation of natural gas to acetylene according to claim 2, Characterized in that: The finned tubes are arranged in the vertical passage of the air passage.

Images