CN102925165A - Afterheat recovery system for raw coke oven gas of coke oven ascension pipe - Google Patents

Abstract

The invention relates to a coke oven riser waste gas waste heat recovery system, which is composed of a riser heat exchanger, a main gas collecting pipe, and a water/steam heat exchanger. The air inlet of the riser heat exchanger is connected to the coke oven. The hot gas outlet of the riser heat exchanger is connected to the main gas collector, and the main gas collector is connected to the water/steam heat exchanger for generating steam or hot water. Under the premise of ensuring the safe operation of the coke oven and not affecting other process requirements of the raw gas, the system can effectively recover more than 50% of the waste heat of the raw gas by using the riser heat exchanger, and reduce the waste gas used for cooling the raw gas. The amount of ammonia water is reduced, and the toxic and harmful wastewater generated in the crude gas purification process is also reduced.

Description

Used in coke oven riser waste gas waste heat recovery system

technical field

The invention relates to a waste heat recovery system for coke oven riser raw gas, in particular to a coke oven riser waste heat recovery system using nitrogen or (air) as a cooling medium.

Background technique

The efficient recovery and utilization of waste heat resources generated in the coking process is the main direction of building a resource-saving and environmentally friendly green coking plant for energy conservation, and it is also one of the main ways to reduce coke oven energy consumption. Among them, the 650°C-700°C raw coal gas that escapes from the carbonization chamber through the riser accounts for 36% of the total output heat of the coke oven. In order to cool the high-temperature raw gas, a large amount of circulating ammonia water at 70°C to 75°C must be sprayed. The high-temperature raw gas is cooled to 82°C to 85°C due to the evaporation of a large amount of circulating ammonia water, and then cooled to 22°C to 35°C through the primary cooler. The heat brought out by the gas is wasted. At present, the waste heat recovery of raw gas is still in the research and development stage, such as heat transfer oil jacketed pipes, heat pipes, boilers, semiconductor thermoelectric power generation and water jackets to recover raw gas to bring out heat. However, some methods and methods have not yet reached industrial production applications.

Contents of the invention

The present invention aims to solve the technical problem of recovering the waste heat of raw coal gas overflowing through the riser pipe in the existing coke oven carbonization chamber, and provides a coke oven riser pipe waste gas waste heat recovery and utilization system. Under the premise of affecting other process requirements of raw gas, using the riser heat exchanger can effectively recover more than 50% of the waste heat of raw gas, and reduce the amount of ammonia water used for cooling raw gas, and also reduce the purification of raw gas Toxic and harmful wastewater generated in the process.

To achieve the above object, the technical scheme adopted in the present invention is as follows:

A waste heat recovery and utilization system for waste gas in the riser tube of coke oven, which is composed of a riser heat exchanger, a main gas collector, and a water/steam heat exchanger. Its characteristics are: the air inlet of the riser heat exchanger is connected to the coke oven Working medium gas outlet, the hot gas outlet of the riser heat exchanger is connected to the main gas collection pipe, and the main gas collection pipe is connected to the water/steam heat exchanger for generating steam or hot water.

Inert gas flows in the return channel of the riser heat exchanger.

A tar outlet pipe is installed at the bottom of the inner wall of the riser heat exchanger to prevent the tar precipitated from the raw coal gas from flowing back to the connection between the bottom end of the riser pipe of the coke oven and the coke oven, so that the outlet of the coke oven gas is coked to form graphite.

The beneficial effects of the present invention are:

Compared with other forms of waste heat recovery and utilization system (device) of coke oven rising pipe raw gas waste heat, the present invention is suitable for waste heat recovery and utilization of waste gas of coking process, and has high operation safety. The structural size of the riser heat exchanger can be the same as that of the original riser, which is convenient for replacement and maintenance; and the area of the heating surface is more reasonable, and the multi-strand spiral return channel is set up in the high temperature section of the raw gas to the greatest extent. The heating surface of the rising tube heat exchanger improves the heat exchange effect between the raw gas and the air or (nitrogen), the air or (nitrogen) can effectively obtain the heat of the raw gas, and at the same time can change the air or (nitrogen) flow energy Controlling the outlet temperature of the raw gas prevents the coking of the riser pipe wall caused by the precipitation of tar in the raw gas when the temperature of the raw gas drops sharply, which affects the safe operation of the coke oven. Using gas as the medium of the heat exchanger can ensure the safe operation of the coke oven in an accident state. If nitrogen is used as the heat transfer medium, it can also be used as supplementary flue gas for the CDQ waste heat boiler, which can improve the operation of the CDQ waste heat boiler. efficiency and output.

Description of drawings

Fig. 1 is a structural principle diagram of the present invention;

Figure 2 is a front view of the riser heat exchanger structure;

Fig. 3 is a sectional view along A-A in Fig. 2;

Fig. 4 is a sectional view along B-B in Fig. 2 .

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in FIG. 1 , the waste heat recovery and utilization system for coke oven riser waste gas of the present invention includes a riser heat exchanger 1 , a main gas collector 2 , a water/steam heat exchanger 3 and the like.

The air inlet of riser heat exchanger 1 is connected to the working gas outlet of the coke oven, the hot gas outlet of riser heat exchanger 1 is connected to the main gas collector 2, and the main gas collector 2 is connected to the water/steam heat exchanger 3 for generating steam or hot water.

As shown in Figures 2, 3, and 4, the riser heat exchanger 1 is composed of inner and outer casings 5, 4, and a multi-strand spiral return channel 6 is set between the inner and outer casings 5, 4, and the inner and outer casings 5, 4 There is a confluence header box at each end. The inert gas flows in the multi-strand spiral return channels 6 of the inner and outer casings of the riser heat exchanger. A tar outlet pipe 7 is arranged at the bottom of the inner wall of the inner casing 5 of the riser heat exchanger to prevent the tar precipitated from the raw gas from flowing back to the connection between the bottom end of the riser pipe of the coke oven and the coke oven, so that coking occurs at the exit of the coke oven gas. Graphite is formed.

The invention utilizes the raw coal gas in the coke oven to pass through the heat exchanger of the rising tube on the top of the coke oven, and transfers the heat of the raw gas to the flowing air or inert gas (nitrogen) in the multi-strand spiral return channels set in the casing of the rising tube heat exchanger , the heated air (nitrogen) flows into the main header after passing through the upper header of the riser heat exchanger. The main gas header gathers the hot air (or nitrogen) generated by multiple riser heat exchangers of the coke oven together, and generates slightly superheated saturated water or superheated steam through the finned tube water/steam heat exchanger for the production process Or life, or superheated steam for power generation.

Claims (3)

1. one kind is used for coke oven coke oven uprising tube raw gas waste heat recycling system, formed by upcast interchanger (1), main effuser (2), water/vapour interchanger (3), it is characterized in that: described upcast interchanger (1) inlet mouth connects the Working medium gas outlet of coke oven, the hot gas outlet of upcast interchanger (1) connects main effuser (2), main effuser (2) connects water/vapour interchanger (3), for generation of steam or hot water.

2. according to claim 1ly it is characterized in that slumpability gas in the return flow line (6) of described upcast interchanger (1) for coke oven coke oven uprising tube raw gas waste heat recycling system.

3. according to claim 1 for coke oven coke oven uprising tube raw gas waste heat recycling system, it is characterized in that, described upcast interchanger (1) inwall bottom arranges a tar delivery line (7), be used for preventing from being back to coke oven coke oven uprising tube bottom and coke oven junction from the tar that raw gas is separated out, form graphite so that coke-oven gas is analysed the exit coking.

Images