CN204943544U - A kind of turbolator-cast iron pipe Combined air preheater - Google Patents

Abstract

The utility model discloses a spoiler-cast iron pipe combined air preheater, which comprises a spoiler air preheater, a flue gas inlet arranged at the top of the spoiler air preheater, and a gas inlet arranged at the top of the spoiler air preheater. The air outlet on the side wall of the spoiler air preheater, the bottom end of the spoiler air preheater is connected to the cast iron pipe air preheater, and the bottom end of the cast iron pipe air preheater is connected to the flue gas outlet The side wall of the cast iron pipe air preheater is provided with an air inlet, and an air channel is connected between the side wall of the cast iron pipe air preheater and the side wall of the spoiler air preheater. The utility model has the advantages of simple structure, low cost and wide fuel applicability, and solves the problem of dew point corrosion of the air preheater.

Description

A spoiler-cast iron pipe combined air preheater

technical field

The utility model relates to a heat exchange device, in particular to a spoiler-cast iron pipe combined air preheater suitable for recovery of waste heat of a heating furnace.

Background technique

At present, the waste heat recovery system of heating furnaces in chemical, petrochemical and coal chemical industries generally uses air preheaters to recover the waste heat in flue gas, so as to improve the thermal efficiency of heating furnaces and reduce operating costs. In theory, in order to improve the thermal efficiency of the heating furnace, the exhaust gas temperature of the heating furnace should be reduced as much as possible. In actual application, due to the influence of sulfur and water content in flue gas components, when the flue gas exhaust temperature drops to a certain level, different degrees of dew point corrosion will inevitably occur at the end of the low-temperature section of the air preheater. Shorten the service life of the air preheater. Air preheaters in the prior art either use one type of heat exchange element, such as spoiler air preheater, heat pipe air preheater, or use combined heat exchange elements, such as spoiler + heat pipe air Preheater, etc. All the above air preheaters have the aforementioned dew point corrosion problem, which affects the service life of the air preheater.

Utility model content

The purpose of the utility model is to overcome the deficiencies in the prior art, and provide a spoiler+cast iron pipe combined air preheater with corrosion resistance, simple structure, low cost and wide fuel applicability.

In order to solve the above technical problems, the utility model provides a spoiler-cast iron pipe combined air preheater, including a spoiler air preheater, and a flue gas inlet installed at the top of the spoiler air preheater , and an air outlet arranged on the side wall of the spoiler air preheater, the bottom end of the spoiler air preheater is connected with a cast iron pipe air preheater, and the bottom end of the cast iron pipe air preheater A flue gas outlet is connected, an air inlet is arranged on the side wall of the cast iron pipe air preheater, and an air passage is connected between the side wall of the cast iron pipe air preheater and the side wall of the spoiler air preheater.

The spoiler air preheater includes a spoiler heat exchange element and a high-temperature section shell arranged outside the spoiler heat exchange element, and the high-temperature section shell and the spoiler heat exchange element are arranged Has high temperature section lining.

The turbulent heat exchange element is one of a spiral grooved tube or a heat exchange tube with a turbulent inner wall.

The cast iron tube air preheater includes a cast iron tube heat exchange element and a low temperature section shell arranged outside the cast iron tube heat exchange element, and a low temperature section liner is arranged between the low temperature section shell and the cast iron tube heat exchange element .

The cast iron tube heat exchange element is composed of an integrally cast base pipe, an inner expansion surface and an outer expansion surface, the inner expansion surface is composed of longitudinal fins distributed axially along the inner wall of the base pipe, and the outer expansion surface It is composed of one of fins or nail heads distributed on the outer wall of the base pipe, and the nail heads are circular or elliptical.

The parts are connected by a sealed connection, the ends of the parts are connected by a flange structure, and a sealing weld is arranged on the outer edge of the flange sealing surface.

The beneficial effects of the utility model are:

1. The utility model uses the silicate protective film formed on the surface of the cast iron pipe heat exchange element through the interaction with the molding sand during the casting process, and the passivation protective film formed on the cast iron surface by the cast iron pipe in the sulfur corrosion environment to protect the lower layer The substrate slows down the corrosion and develops deeper into cast iron, improving the dew point corrosion resistance of cast iron tube heat exchange elements;

2. The high-temperature section of the utility model adopts the spoiler heat exchange element, and utilizes its advantages of simple structure, mature technology, and low cost. Only the cast iron tube heat exchange element is used in the low temperature section, and its excellent dew point corrosion resistance is used to avoid the disadvantages of using all cast iron tube air preheaters, which lead to heavy weight and high cost of the air preheater. The device of the utility model fully utilizes the advantages of the single spoiler and the single cast iron pipe two air preheaters while avoiding their limitations and deficiencies, and has high comprehensive cost performance;

3. The fuel of the utility model has wide applicability. Common soot blowers can be used to remove ash after the cast iron pipe heat exchange element has accumulated ash. Therefore, it is not only suitable for waste heat recovery systems of gas-fired heating furnaces, but also suitable for waste heat recovery systems of oil-fired heating furnaces with heavy ash content.

Description of drawings

Figure 1: Schematic diagram of the structure of the utility model;

Figure 2-1: Schematic diagram of the structure of the cast iron tube heat exchange element with fins on the outer expansion surface of the utility model;

Figure 2-2: Schematic diagram of the structure of the cast iron tube heat exchange element with the nail head as the outer expansion surface of the utility model.

Drawings: 1. Flue gas inlet; 2. Spoiler air preheater; 3. Cast iron pipe air preheater; 4. Flue gas outlet; 5. Air inlet; 6. Air channel; 7. Air outlet; 8. Spoiler heat exchange element; 9. High temperature section lining; 10. High temperature section shell; 11. Cast iron pipe heat exchange element; 12. Low temperature section lining; 13. Low temperature section shell; 14. Base pipe; 15. Inner expansion surface; 16. External expansion surface.

detailed description

Below in conjunction with accompanying drawing, the utility model is further described.

As shown in Figure 1-2, a turbulent-cast iron pipe combined air preheater includes a turbulent air preheater 2, and the turbulent air preheater 2 includes a turbulent heat exchanger The element 8 and the high temperature section shell 10 arranged outside the turbulent heat exchange element 8, a high temperature section liner 9 is arranged between the high temperature section shell 10 and the turbulent heat exchange element 8; the turbulent flow The sub-heat exchanging element 8 is one of spiral grooved tubes or heat exchanging tubes with spoilers on the inner wall. The top of the spoiler air preheater 2 is connected with a flue gas inlet 1 , and its side wall is connected with an air outlet 7 . The bottom end of the spoiler air preheater 2 is connected with a cast iron pipe air preheater 3, and the cast iron pipe air preheater 3 includes a cast iron pipe heat exchange element 11 and is arranged outside the cast iron pipe heat exchange element 11. The low-temperature section shell 13, the low-temperature section liner 12 is arranged between the low-temperature section shell 13 and the cast iron pipe heat exchange element 11; and the outer expansion surface 16, the inner expansion surface 15 is composed of longitudinal fins distributed axially along the inner wall of the base pipe 14, and the outer expansion surface 16 is formed by fins or nails distributed on the outer wall of the base pipe 14 One of the configurations of the nail head, the nail head is round or oval. The bottom end of the cast iron pipe air preheater 3 is connected with a flue gas outlet 4, and the side wall of the cast iron pipe air preheater 3 is provided with an air inlet 5, and the side wall of the cast iron pipe air preheater 3 and the spoiler An air passage 6 is connected between the side walls of the sub-air preheaters 2 . Sealed connections are adopted between the components, that is, the ends of the components are firstly connected by a flange structure, and then a sealing weld is added to the outer edge of the flange sealing surface to further reduce the leakage rate of the air preheater.

The method for recovering the waste heat of the heating furnace by utilizing the device of the utility model includes the following steps: first, prepare and install the above-mentioned air preheater; after the installation is completed, the high-temperature flue gas discharged from the heating furnace enters the air preheating through the flue gas inlet 1 At the same time, the low-temperature air enters the air preheater through the air inlet 5; the high-temperature flue gas entering the air preheater flows through the spoiler air preheater 2 and the cast iron pipe air preheater 3 in sequence after exchanging heat with the air. The low-temperature flue gas leaves the air preheater through the flue gas outlet 4; at the same time, the low-temperature air entering the air preheater flows through the cast iron pipe air preheater 3, the air channel 6 and the spoiler air preheater 2 and After the heat exchange of the flue gas, the temperature rises, and the high-temperature air leaves the air preheater through the air outlet 7, and the waste heat in the flue gas is recovered.

Claims (6)

1. A spoiler-cast iron pipe combined air preheater, comprising a spoiler air preheater, a flue gas inlet arranged at the top of the spoiler air preheater, and a flue gas inlet arranged at the spoiler air preheater The air outlet on the side wall of the sub-air preheater is characterized in that the bottom end of the spoiler air preheater is connected to a cast iron pipe air preheater, and the bottom end of the cast iron pipe air preheater is connected to a flue gas An air inlet is provided on the side wall of the cast iron pipe air preheater, and an air passage is connected between the cast iron pipe air preheater side wall and the spoiler air preheater side wall. 2. The spoiler-cast iron pipe combined air preheater according to claim 1, characterized in that, the spoiler air preheater comprises a spoiler heat exchange element and is arranged on the spoiler A high-temperature section shell outside the heat exchange element, and a high-temperature section liner is arranged between the high-temperature section shell and the turbulent heat exchange element. 3. The spoiler-cast iron tube combined air preheater according to claim 2, wherein the spoiler heat exchange element is a spiral grooved tube or a heat exchange tube with a spoiler on the inner wall. a composition. 4. The spoiler-cast iron pipe combined air preheater according to claim 1, characterized in that, the cast iron pipe air preheater comprises a cast iron pipe heat exchange element and a heat exchange element arranged on the cast iron pipe heat exchange element The low-temperature section shell on the outside, a low-temperature section liner is arranged between the low-temperature section shell and the cast iron pipe heat exchange element. 5. The spoiler-cast iron tube combined air preheater according to claim 4, wherein the cast iron tube heat exchange element is composed of an integrally cast base tube, an inner expansion surface and an outer expansion surface, and the The inner expansion surface is composed of longitudinal fins distributed axially along the inner wall of the base pipe, and the outer expansion surface is formed by one of the fins or nail heads distributed on the outer wall of the base pipe, and the nail head is round or oval. 6. The spoiler-cast iron pipe combined air preheater according to claim 1, characterized in that, the parts are sealed and connected, and the sealed connection is that the ends of the parts are connected by a flange structure , a sealing weld is arranged on the outer edge of the flange sealing surface.