JPS6014790B2 - Method and device for monitoring and controlling high-temperature gasification process - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and a device for temperature control and monitoring of reaction progress during the partial oxidation of ash-containing liquid or dusty solid fuels, in particular under high pressure.

In the production technology of CO- and CO-containing gases, partial oxidation of gaseous, liquid or solid dust fuels in flame reactions using industrial oxygen or free oxygen-containing gasifiers has been introduced. In order to guarantee a high specific efficiency and a sufficient throughput, temperatures of 1200 to 1500 qC are required in this case, much higher temperatures occurring in the flame itself. When ash-containing fuels, especially dusty fuels, are used, the ash is then generated in a molten fluid state. For the operation and technical safety of partial oxidation reactors, knowledge of the temperature prevailing in the reaction chamber is extremely important.

As such, this temperature is an indicator of the free oxygen to fuel ratio and of the presence of a flame within the reaction chamber. If the flame in the reaction chamber is unintentionally extinguished, for example due to fuel starvation, a large explosion of soot can occur due to the ingress of free oxygen into the crude gas cooling purification equipment which follows the reaction chamber. In addition, if ash-containing fuels are used, it must be ensured that the reaction chamber temperature is as high as necessary to ensure satisfactory melt flow of the ash. Otherwise, there may be "icing up" of the slag outlet or of the entire reactor due to solidification of the slag.
Measuring the temperature in the reaction chamber is particularly difficult when partial reactions are carried out under high pressures, for example 2 to 4 MPa (megapascals: IMPa corresponds to about 1 p atm).

Despite these drawbacks, temperature measuring devices have been developed for devices intended to use gaseous and liquid fuels. Temperature measurement is now an important element of emergency response systems and process control. In contrast, no satisfactory solution for temperature measurement in reactors using ash-containing fuels is known.

The materials available for thermocouple protection tubes are melted by the molten flowable ash, or their resistance to the inevitable alternating heat loads is significantly adversely affected by the penetration of the molten flowable ash. In both cases, therefore, reaction chamber temperature measurements using thermocouples are possible for relatively short periods of time. However, the achievable lifetime of thermocouples is quite insufficient for economical continuous operation, since in systems with high operating pressures the replacement of the thermocouple is inseparable from the shutdown of the system. When attempting to use optical radiometry for temperature measurement, there is a risk of slag clogging of the necessary sight holes in the reaction chamber walls and of fouling and fogging of the optical windows, which also result in insufficient duration being achieved. Become. For the partial oxidation of ash-containing fuels, especially dusty solid fuels, reactors are known in which the reaction chamber is delimited by a cooling shield, such as a tube wall structure through which cold soot passes.

The tube wall, which usually consists of a studded tube, is covered with a thin layer of refractory lagoon on the side facing the reaction chamber. A thin layer of solidified slag and a film of flowing molten slag form on this solidified material during operation, depending on the balance between cooling and heat transfer from the reaction chamber.

In reactors for high-pressure operation, the tube wall structure that defines the actual reaction chamber is housed in an outer pressure vessel. Technological solutions are known in which high-pressure water is used as a cold filter and the high-pressure water flow or inlet temperature is adjusted so that the boiling point is not reached at the respective pressure. The object of the invention is to provide a method for controlling temperature and monitoring and controlling the reaction progress during the partial oxidation of ash-containing, especially dusty, solid fuels, preferably under high pressure, in a reactor whose reaction chamber is surrounded by a cooling shield. A method and apparatus.

The invention involves monitoring the prevailing temperature and the reaction progress in the reaction chamber of a reactor for the partial oxidation of ash-containing liquid or dusty solid fuels and using the measurements obtained for process control;
The problem is to develop methods and devices that can be used to guarantee a sufficiently long measuring device duration.

The present invention is directed to a reactor in which the reaction chamber is surrounded by a cooling shield that passes cold soot. According to the invention, this task is achieved by measuring the amount of heat flowing out per unit time from the cooling shield surrounding the reaction chamber or from a part thereof, and by comparing this amount of heat per unit time with respect to the cooling shield or part of the cooling shield surrounding the reaction chamber. control of the process, in particular of the temperature, by influencing the ratio of the amounts of free oxygen and fuel fed into the reactor per unit time and/or as a measure of the average temperature of the reaction chamber sections that are Or it can be solved by using it to activate the emergency measures system.

In particular, in the present invention, the cooling shield surrounding the reaction chamber is formed of a tube wall structure consisting of one or parallel tubes, into which water, preferably high-pressure water, is fed as soot, and the maximum temperature of the water is Used in reactors where the boiling point is kept below the pressure prevailing in the tube. In this case the tube or one of the tubes
The amount of water fed into the cooling pipe per unit time is measured by a known method, and the water temperature in the cooling pipe is measured at at least two side temperature points distributed over the entire length of the cooling pipe. Therefore, the product of the amount of water fed per unit time and the temperature difference of high-pressure water is used as a measure of the average temperature of the reaction chamber portion between these side temperature points and/or for process control and/or
Or used to activate the emergency intelligence system. The time for the device of the invention to respond to the temperature fluctuations prevailing in the reaction chamber is surprisingly short, compared to that of thermocouple devices in similar reactors operating on substantially ash-free gaseous or liquid fuels. is within the same range.

It is another advantage of the process according to the invention that the signal obtained is significantly broadened in the reaction temperature range above the technologically important fuel ash melting point and is therefore very sensitive to variations in the reaction operation. Although the measuring method of the present invention does not directly yield a statement about the absolute value of the reaction chamber temperature, if the melting behavior of the fuel ash is constant, there is still a difference between the signal and the average temperature prevailing in the reaction chamber section. There is sufficient correlation.

When the melting point of the fuel ash changes, it is important for operation that the absolute temperature of the reaction chamber associated with a particular level of signal obtained in the reaction chamber temperature range above the melting point of the fuel ash is in the same direction as the change in the melting point of the fuel ash and approximately the same as that of the change in the melting point of the fuel ash. move to the same extent.

This behavior occurs, for example, because in the case of an increase in the ash melting point, the slag mass adhering to the cooling shield becomes thicker and the same amount of heat is only applied to the cold soot after the reaction chamber temperature has increased. This is not a drawback. The minimum reaction chamber temperature that is acceptable for satisfactory operation is usually determined by the solidification temperature of the molten slag. As the melting point increases, the reaction chamber temperature must be increased accordingly. However, the signal obtained by the invention is the same in both cases. Therefore, fluctuations in the melting behavior of the fuel ash can be directly utilized for adjusting the oxygen-fuel ratio, which has a decisive influence on process control, especially on reaction chamber temperature control. In the case of process control via direct measurement of the reaction chamber temperature, constant inspection control of the ash melting behavior is additionally required to avoid "icing up" of the reactor due to solidified slag in the event of changes in the ash melting behavior. Become. In the present invention, we measure not only the average value of the reaction chamber temperature, which applies to the entire reaction chamber, but also the heat transferred in different parts of the cooling shield, in the case of a corresponding design, to several parts of the reaction chamber. It is a particular advantage of the invention that the temperature of the part can also be known.

The invention provides that the reaction chamber is surrounded by a cooling shield in the form of a tube wall structure consisting of one or more textbook parallel tubes, which cooling shield is operated with water, preferably with high pressure water, and the maximum water temperature is below the boiling point. It is preferentially used in conjunction with a reactor that is maintained.

The mode of implementation of the invention suitable for this type of reactor is distinguished by the features described below.

At least one of the parallel tubes wound around multiple coils is equipped with a flow meter for measuring the amount of high-pressure water flowing past per unit time.

In easily accessible locations, usually outside the reactor housing, thermocouples of various lengths, preferably in the form of thin jacketed thermocouples, are inserted into the tubes in question through suitable pressure-tight, pressure-tight bushings known in the art. so that the junctions producing the thermovoltage are in the section of the tube forming the cooling shield inside the reactor, and the length of the thermocouple is such that the junctions are distributed over the entire length of the section. It is determined that According to the invention, the thermocouple can be inserted into the tube from the inlet side, the outlet side or both sides. The thermocouples are grouped together with the fusible wire or element in one direction, and the wire or element runs the entire length of the tube and after opening the pressure-tight bushing that penetrates the tube wall, there is no need to open the entire reactor. It has been found to be an advantageous implementation to be able to act as a towbar for rapid exchange of thermocouples. The thermocouples are interconnected in a known manner so that the voltage generated in each case is a measure of the temperature difference in the high-pressure water between two hot spots, preferably two adjacent hot spots.

The temperature difference signal is combined in a suitable manner with the flow meter signal to obtain a signal proportional to the product of flow rate and temperature difference.

At least one uniform signal is connected to a display device and/or a control system for oxygen-fuel ratio adjustment and/or an emergency action system. The present invention will be explained below with reference to the drawings.

Example 1 The reactor of a fine lignite partial oxidation device using industrial oxygen at a pressure of 4 MPa has an outer pressure-resistant container 1 containing a number of cylindrical coiled flexible tubes 2 arranged vertically as shown in Fig. 1. As shown in FIG. 2, the side of the tube facing the reactor centerline is coated with a refractory material.

Steel studs 4 on the pipe surface support the Hatooka village. A corrugated pipe with hardwood surrounds the original reaction chamber 5, in which the chemical changes of the reaction components, powdered lignite, industrial oxygen and (a small amount) water vapor fed from the burner 6 occur at high temperatures. It is done. The fuel ash becomes molten and fluid within the reaction chamber. A part of the fluid ash solidifies on the wall formed by the covered corrugated tube of the reaction chamber to form a slag shell 7, and the other part forms a molten slag film 8 on this shell 7, which flows down and is generated. The crude gas passes from the reactor via the outlet opening 9 to the cooling and separation device of the back bowl. Water is fed into the corrugated tube for cooling, the amount of which is adjusted so that the maximum water temperature is below the boiling point at the prevailing pressure in the tube. In FIG. 1, a flow meter 10 is shown for one flexible pipe, but the amount of water flowing through the pipe per unit time is measured. At the same time, thermocouples 13 and 14 are attached to the inlet 11 and outlet 12 of the corrugated pipe for measuring the water temperature at these points. Both thermocouples are interconnected in such a way that only one signal is emitted, which corresponds to the temperature difference between fixed points on both sides. The flow measurement and temperature measurement signals are combined in the measurement value conversion device 15 using logic blocks to produce a signal proportional to the product of the flow rate and the temperature difference per unit time. This signal is used as a measure of the average temperature in the reaction chamber around the corresponding tube.
6 and record the statement. The signal is further sent to a controller 17 which in turn controls a valve 18 serving as a control element in the oxygen inlet line.
The ratio of the amount of oxygen per unit time to the amount of pulverized coal per unit time is corrected through the metering device 19, while the predetermined pulverized coal flow rate is
is kept unchanged by Finally, the signal of the measured value converter 15 is transferred to an automatic emergency response system (emergency measures system) 20.
If the upper limit value is exceeded and the lower limit value is exceeded, this will cause the device to shut down and transition to a non-hazardous state.

In addition to other switching procedures, the oxygen supply to the reactor is then closed without delay, in particular by means of the quick-shutoff valve 21. For the reactor used in this example, the ash melting point is 1250
When using lignite with a qo characteristic, a relationship was obtained between the signal produced by the measured value converter 15 and the average temperature in the reaction chamber around the perplexing tube, as shown in the curve shown in FIG.

Satisfactory operation of the apparatus with respect to slag discharge is achieved at a reaction chamber temperature of 145 pico C. at this point. This corresponds to a 20% signal according to FIG. From this, the melting point is 200
When using high qo powdery lignite, the characteristics shown by curve b in Figure 3 were restricted. This curve has effectively shifted to the right by 20 pi○. The perfect operation using this charcoal is also 2
This is achieved with a signal of 0%, ie when the specific heat transfer to the coils of the cooling shield is equal. Example 2 In another embodiment of the high-pressure water-cooled reaction chamber shown in FIG. The reactor chamber 5 is covered with a refractory dome material on its side facing the reactor center line, forming an envelope for the reaction chamber 5.

The upper and lower ends of each tube are led out through the bottom and lid of the pressure container 1 in a pressure-tight and airtight manner via a technical tube 23, and the inlet 1 of the tube is
1 and an outlet 12. Although one pipe is shown in FIG. 4, a high pressure water flow meter is attached to the inlet 11.

At the water inlet bend in the immediate vicinity of the branch pipe 23, five thin jacketed thermocouples of various lengths are inserted into the pipe via pressure-tight and airtight pushing 24. The hot junctions 26 of these thermocouples are evenly distributed over the length of the reactor interior of the tube. The difference in thermovoltage of the two thermocouples, each of phosphoric acid, is passed on to a measured value converter 15. Other equipment is the same as that of the first embodiment. The same applies to the relationship between the temperature in the reaction chamber and the relative value of the signal obtained by the measurement value conversion device 15, which is the product of the high-pressure water volume per unit time and the temperature difference. Further, as shown in FIG. 5, the jacketed thermocouples and the thin steel cables 27 are grouped together in one east by a strap 31.

The steel material is guided along the entire length of the tube and held at an easily accessible point in the upper end of the tube 22 and in the branch tube 28 outside the pressure vessel 1 with a holder 29.
It is fixed at The branch pipe 28 with the holder is closed by the lid 3. By placing the thermocouple with a narrow jacket of about 1 sail and the steel element on the east side, sufficient mechanical stability of the device is achieved against the loads induced in the pipe by high pressure water. The durability of the thermocouple structure is satisfactory. At the same time, the steel material serves as an aid when installing or replacing the thermocouple.

[Brief explanation of drawings]

Figure 1 is a diagram of a measuring device for a reactor consisting of vertically arranged corrugated tubes with cooling shields connected in parallel to the textbook, Figure 2 is a tube cover covered with a recording material and slag, and Figure 3 is The relationship between the temperature of the reaction chamber and the relative value of the product of the high-pressure water volume per unit time and the high-pressure water temperature difference over the measuring length, Figure 4 shows that the cooling shield is in the form of a multi-strand coil of parallel tubes in the textbook. FIG. 5 shows details of the thermocouple structure of FIG. 4. DESCRIPTION OF SYMBOLS 1... Outer pressure-resistant container, 2... Serpentine pipe, 3... Torigomura, 4... Steel stud, 5... Reaction chamber, 6... Burner, 7... Slag shell, 8... Molten slag film, 9...
Outlet checkpoint, 10...flow meter, 11...inlet, 12...
Outlet, 13... Inlet thermocouple, 14... Outlet thermocouple,
15... Measured value conversion device, 16... Recorder, 17.
...Controller, 18...Valve, 19...Pulverized coal quantitative device, 20...Emergency measure system, 21...Quick shut-off valve, 22...Pipe, 23...Branch pipe, 24...Pressure resistance Airtight bushing, 25... thermocouple with jacket, 26... high temperature side support point,
27... Steel material, 28... Branch pipe, 29... Holder,
30...Lid, 31...Obi. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] 1. A reactor for the partial combustion of ash-containing fuels, the reaction chamber of which is surrounded by a cooling shield of tube wall structure consisting of one or several parallel tubes, the shield comprising: In a method for monitoring and controlling the reaction progress in water, preferably operated using high-pressure water and in which the maximum water temperature is kept below the boiling point,
The amount of water injected per unit time into at least one tube of the cooling shield is measured by a suitable method, and the water temperature is measured at several at least two points distributed over the length of one tube of the shield. Calculate the product of the amount of water measured at a temperature point and sent in per unit time and the difference in water temperature measured at two temperature measurement points in the pipe, preferably two adjacent temperature points, and calculate this calculated product. as a measure of the average temperature of the reaction chamber section associated with the section of the tube between the temperature points and/or for process control, in particular influencing the amount of free oxygen and fuel fed into the reactor during a unit time; A method characterized in that it is used for controlling the temperature in a reaction chamber by exerting a 2. The reaction chamber is surrounded by a cooling shield in the form of a tube wall structure consisting of one or several parallel tubes, which shield is
In an apparatus for carrying out a method for monitoring and controlling the reaction progress in a reactor which is preferably operated using high-pressure water and whose maximum water temperature is kept below the boiling point, the tubes in the tube wall may be single or multi-threaded. The tube, or at least one of the parallel tubes, is equipped with a measuring device for the amount of water passing through the tube per unit time. At the point of access, usually outside the reactor housing, thin thermocouples of various lengths, preferably in the form of thin jacketed thermocouples, are inserted into the tubes in question via pressure-tight bushings known in principle. , the length of the thermocouples is such that the junction points producing the thermocouples are distributed over the entire length of the tube in the reactor, and the water measuring device and at least two thermocouples of different lengths are provided. The output signal conductor of is connected to a measured value conversion device, for example a combination of logic blocks, which then combines the input signals and calculates the difference between the amount of water flowing through unit time and the difference in thermal voltage of the respective pair of thermocouples. one or several output signals proportional to the product, the output signal conductors of the measured value conversion device being connected to a display device and/or a process control system and/or an emergency measures system. A device characterized by: 3. The thermocouples are bundled together with flexible wires or cables, the latter being in the water flow in the pipe, and the flexible wires or cables running the length of the pipe and in easily accessible locations.・
3. Device according to claim 2, characterized in that it is normally fixed outside the reactor housing, preferably in a branch pipe which is closed by a bend, an inlet and an outlet cap of the pipe.