CN209085376U - A low-pressure heat exchanger for two-stage dry pulverized coal gasifier - Google Patents

Abstract

The utility model discloses one kind to be used for two sections of dry coal dust gasification furnace low pressure heat exchangers, including shell and heat exchanging pipe, the top of shell is equipped with water inlet pipe, water inlet pipe insertion is set in shell, and it is connected to shell, the bottom of water inlet pipe is connected with comb, the side of comb is equipped with the spray head of several symmetric arrays, the adjacent side of water inlet pipe is equipped with steam (vapor) outlet, steam (vapor) outlet is connected to shell, heat exchanging pipe is arranged in the bottom of comb, and the end of heat exchanging pipe is respectively equipped with synthesis gas entrance and syngas outlet, the bottom of shell is equipped with symmetrical support leg, support leg is fixed with case weld.With raising boiler feed temperature, change boiler feedwater water intake mode, local overcooling is avoided to form ammonia salt crystallization, solves heat exchange blockage and ammonia salt corrodes the advantages of heat exchanger tube leads to heat exchanger tube leakage problem.

Description

A low-pressure heat exchanger for two-stage dry pulverized coal gasifier

technical field

The utility model relates to the technical field of heat exchangers, in particular to a low-pressure heat exchanger for a two-stage dry pulverized coal gasifier.

Background technique

A heat exchanger is a device that transfers part of the heat of a hot fluid to a cold fluid, also known as a heat exchanger. Heat exchangers play an important role in chemical, petroleum, power, food and many other industrial productions. Heaters can be widely used as heaters, coolers, condensers, evaporators and reboilers. In the field of coal chemical industry, coal gasification requires a pulverized coal gasifier to operate, and a heat exchanger is an essential part of the gasifier.

However, after analysis, it is found that the existing low-pressure heat exchangers used in the second-stage dry pulverized coal gasifier have the following deficiencies; Leaks to the water vapor side.

Utility model content

Therefore, in order to solve the above deficiencies, the present utility model provides a low-pressure heat exchanger for a two-stage dry pulverized coal gasifier, which has the functions of increasing the temperature of the boiler feed water, changing the water inlet mode of the boiler feed water, and avoiding local subcooling to form ammonia salts. Crystallization solves the advantages of heat exchange tube blockage and ammonia salt corrosion heat exchange tube leakage problem.

The utility model is realized by constructing a low-pressure heat exchanger for a two-stage dry pulverized coal gasifier, which includes a shell and a heat exchange pipeline. The top of the shell is provided with a water inlet pipe, and the water inlet pipe is embedded in the shell. The bottom of the water inlet pipe is connected with a row pipe, the side of the row pipe is equipped with a number of nozzles arranged symmetrically, the adjacent side of the water inlet pipe is provided with a steam outlet, the steam outlet is communicated with the casing, and the heat exchange pipeline It is arranged at the bottom of the exhaust pipe, and the ends of the heat exchange pipeline are respectively provided with a synthesis gas inlet and a synthesis gas outlet, and the bottom of the shell is provided with symmetrical support feet, which are welded and fixed with the shell.

Further, the drain pipe is buried below the liquid level in the casing. The boiler feed water is fed from the top through the set exhaust pipes and water inlet pipes, and the exhaust pipes are buried below the liquid level in the heat exchanger. The heating temperature of the water in the center of the heat exchange pipeline increases, the density becomes smaller and rises, and the influent water is sucked into the lower part of the heat exchange area to continue heating, thus forming a kettle-type boiling design, because the water entering the heat exchange pipeline has been heated to the saturation temperature, Thereby, the temperature of the local heat exchange tube is prevented from being too low, and the corrosion of salt accumulation in the tube is prevented.

Further, symmetrical temperature measuring ports are provided on the side of the heat exchange pipeline. It is convenient to use the special standard temperature to monitor the temperature of the heat exchange pipeline in real time through the set temperature measurement port.

Further, the bottom of the heat exchange pipeline is provided with a bottom heating pipe. The set heating tube can heat the feed water to 200 degrees Celsius with medium pressure steam in the initial stage of the heat exchanger, which reduces the preheating time. After the temperature is normal, the heating can be cut off, which helps to improve the heat exchange efficiency.

The utility model provides a low-pressure heat exchanger for a two-stage dry pulverized coal gasifier by improving, which has the following advantages compared with the existing low-pressure heat exchanger for a two-stage dry pulverized coal gasifier: Boiler feed water temperature, changing the way the boiler feed water enters, avoiding local subcooling to form ammonia salt crystallization, and solving the problems of heat exchange tube blockage and ammonia salt corrosion of heat exchange tubes leading to heat exchange tube leakage, the advantages are embodied as follows:

Advantage 1: The drain pipe is buried below the liquid level in the shell. The boiler feed water is fed from the top through the set exhaust pipes and water inlet pipes, and the exhaust pipes are buried below the liquid level in the heat exchanger. The heating temperature of the water in the center of the heat exchange pipeline increases, the density becomes smaller and rises, and the influent water is sucked into the lower part of the heat exchange area to continue heating, thus forming a kettle-type boiling design, because the water entering the heat exchange pipeline has been heated to the saturation temperature, Thereby, the temperature of the local heat exchange tube is prevented from being too low, and the corrosion of salt accumulation in the tube is prevented.

Advantage 2: There is a bottom heating tube at the bottom of the heat exchange pipeline. The set heating tube can heat the feed water to 200 degrees Celsius with medium pressure steam in the initial stage of the heat exchanger, which reduces the preheating time. After the temperature is normal, the heating can be cut off, which helps to improve the heat exchange efficiency.

Description of drawings

1 is a schematic structural diagram of a low-pressure heat exchanger used in a second-stage dry pulverized coal gasifier according to the present invention;

Figure 2 is a longitudinal cross-sectional view of a low-pressure heat exchanger used in a two-stage dry pulverized coal gasifier according to the present invention.

The serial numbers shown in the figure: shell 1, heat exchange pipe 2, steam outlet 3, water inlet pipe 4, exhaust pipe 5, nozzle 6, temperature measurement port 7, support foot 8, bottom heating pipe 9, synthesis gas inlet 10 and Syngas outlet 11.

Detailed ways

The present invention will be described in detail below with reference to accompanying drawings 1 to 2, and the technical solutions in the embodiments of the present invention will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present invention, not All examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention; in addition, the terms "first", "second" ", "third", "up, down, left, right" etc. are for descriptive purposes only and should not be construed as indicating or implying relative importance. Meanwhile, in the description of the present invention, unless otherwise expressly specified and limited, the terms "connected" and "connected" should be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection ; It can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

The utility model provides a low-pressure heat exchanger for a two-stage dry pulverized coal gasifier by improving, as shown in Figures 1-2, which can be implemented in the following manner; including a shell 1 and a heat exchange pipeline 2. The top of the casing 1 is provided with a water inlet pipe 4, which is embedded in the casing 1 and communicated with the casing 1. The bottom of the water inlet pipe 4 is connected with a drain pipe 5, and the side of the drain pipe 5 is installed with several Symmetrically arranged nozzles 6, the adjacent side of the water inlet pipe 4 is provided with a steam outlet 3, the steam outlet 3 is communicated with the shell 1, the heat exchange pipe 2 is arranged at the bottom of the row pipe 5, and the end of the heat exchange pipe 2 A synthesis gas inlet 10 and a synthesis gas outlet 11 are respectively provided. The bottom of the casing 1 is provided with symmetrical supporting feet 8 , and the supporting feet 8 are welded and fixed to the casing 1 .

The drain pipe 5 is buried below the liquid level in the casing 1 . The boiler feed water is fed from the top through the set exhaust pipe 5 and the water inlet pipe 4, and the exhaust pipe 5 is buried below the liquid level in the heat exchanger. Mixing heating, because the heating temperature of the water in the center of the heat exchange pipeline 2 increases, the density becomes smaller and rises, and the influent water is sucked into the lower part of the heat exchange area to continue heating, thus forming a kettle-type boiling design, because the water entering the heat exchange pipeline 2 It has been heated to the saturation temperature, thereby avoiding the low temperature of the local heat exchange tube and preventing the corrosion of salt accumulation in the tube.

A symmetrical temperature measuring port 7 is opened on the side of the heat exchange pipeline 2 . It is convenient to use the special standard temperature to monitor the temperature of the heat exchange pipeline 2 in real time through the set temperature measurement port 7 .

The bottom of the heat exchange pipeline 2 is provided with a bottom heating pipe 9 . The heating pipe 9 can be used to heat the feed water to 200 degrees Celsius in the initial stage of the heat exchanger, which reduces the preheating time. After the temperature is normal, the heating can be cut off, which helps to improve the heat exchange efficiency.

The working principle of the low-pressure heat exchanger used in the second-stage dry pulverized coal gasifier: the heat exchanger is arranged between the dry dust removal system and the washing tower process. The boiler feed water is fed from the water inlet pipe 4 at the top, and the drain pipe 5 is buried below the liquid level in the heat exchanger. The nozzle 6 is set on the drain pipe 5, so that the feed water is mixed and heated by the boiler water in the upper part. , because the heating temperature of the water in the center of the heat exchange pipeline 2 increases, the density becomes smaller and rises, and the influent water is sucked into the lower part of the heat exchange area to continue heating, thus forming a kettle-type boiling design, because the water entering the heat exchange pipeline 2 has been heated. To the saturation temperature, the temperature of the local heat exchange tube is prevented from being too low, and the corrosion of salt accumulation in the tube is prevented. The boiler feed water is heated by the syngas, and steam is generated in the upper part of the heat exchanger and leaves the boiler from the steam outlet 3, and the synthetic gas is recovered. The heat generated by the gas is sent to the power island to generate electricity.

To sum up, compared with the existing low-pressure heat exchanger used in the second-stage dry pulverized coal gasifier, the utility model has the advantages of increasing the boiler feed water temperature, The boiler feed water inlet mode is changed to avoid local subcooling to form ammonia salt crystallization, which solves the advantages of heat exchange tube blockage and ammonia salt corrosion heat exchange tube leakage problem.

The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (4)

1. one kind is used for two sections of dry coal dust gasification furnace low pressure heat exchangers, including shell (1) and heat exchanging pipe (2), it is characterised in that: The top of the shell (1) is equipped with water inlet pipe (4), and water inlet pipe (4) insertion is set in shell (1), and even with shell (1) Logical, the bottom of the water inlet pipe (4) is connected with comb (5), and the side of the comb (5) is equipped with the spray head of several symmetric arrays (6), the adjacent side of the water inlet pipe (4) is equipped with steam (vapor) outlet (3), and the steam (vapor) outlet (3) is connected to shell (1), the heat exchange Pipeline (2) is arranged in the bottom of comb (5), and the end of the heat exchanging pipe (2) is respectively equipped with synthesis gas entrance (10) and closes (11) are exported at gas, the bottom of the shell (1) is equipped with symmetrical support leg (8), and the support leg (8) and shell (1) are welded It is fixed.

2. a kind of according to claim 1 be used for two sections of dry coal dust gasification furnace low pressure heat exchangers, it is characterised in that: the comb (5) it is embedded to shell (1) interior liquid level or less.

3. a kind of according to claim 1 be used for two sections of dry coal dust gasification furnace low pressure heat exchangers, it is characterised in that: the heat exchange The side of pipeline (2) offers symmetrical temperature measurement mouth (7).

4. a kind of according to claim 1 be used for two sections of dry coal dust gasification furnace low pressure heat exchangers, it is characterised in that: the heat exchange The bottom of pipeline (2) is equipped with bottom-heated pipe (9).