1. The designed service life of the pressure vessel is not equal to the actual service life.The design service life is an expected target value, not a guaranteed value, nor can it be regarded as the time limit for the scrapping of the pressure vessel.The actual service life of the pressure vessel shall be determined according to the actual use conditions, inspection results, failure modes, etc., which may be higher than or lower than the design service life.2. The design service life shall be determined by the design unit according to the expected service life of the container, and shall be indicated in the design drawings.The JC/T720 "Autoclave" standard stipulates: "Under normal operating conditions, the design service life of the autoclave is 15 years." 3. TSG21-2016 "Stationary Pressure Vessel Safety Technical Supervision Regulations" is determined "3.1.11 Corrosion allowance", the concept of design service life is mentioned.Provisions: "For pressure vessels with uniform corrosion, the corrosion allowance is based on the expected service life of the pressure vessel and

Waste heat resources refer to the energy that may be recycled but not yet recycled under existing conditions, and is considered to be the fifth largest conventional energy after coal, oil, natural gas and hydropower.According to its source, it can be divided into six categories: high-temperature flue gas waste heat (the highest proportion, reaching 50%), cooling medium waste heat, waste heat of waste gas and waste water, waste heat of high-temperature products and slag, chemical reaction heat, waste heat of combustible waste gas and waste liquid and waste heat.These waste heat resources can be used for power generation, driving machinery, heating or cooling, etc., thus reducing the consumption of primary energy and reducing thermal pollution to the environment.my country's industrial energy consumption accounts for about 70%.Industrial enterprises are major energy consumers in China (such as steel, metallurgy, building materials and other industries), and their energy consumption accounts for about 70% of the country's total energy consumption. The average unit energy consumption of major industrial products is about 30% higher than the international advanced level.In addition to the relatively backward production technology and unreasonable industrial structure, the utilization rate of industrial waste heat is low

There are roughly the following types of deaerators: atmospheric thermal deaerator; chemical deaerator (dosing and deaerator); analytical deaerator; vacuum deaerator; sponge iron deaerator, etc. The most widely used is atmospheric deaerator; Drug deaeration is mainly applied to small boilers; analytical deaeration currently has mature theories but no mature technology; vacuum deaeration is very effective, but the cost is high and it is not easy to control; sponge iron deaeration efficiency is very low, Belongs to the elimination type.The atmospheric thermal deaerator heats the water to reduce the solubility of oxygen, the oxygen in the water continuously escapes, and then the oxygen generated on the water surface is removed together with the water vapor, which can remove various gases in the water (including free CO2, N2).Deoxygenated water does not increase the salt content, nor does it increase the amount of other gases dissolved.The operation and control of the atmospheric thermal deaerator is relatively easy, and the operation is stable and reliable.In theory, the partial pressure of oxygen in the boiling state is zero, and the pressure of the ordinary thermal deaerator controls the deaerator to about 0

The soot blowers used in boilers include steam soot blowers, sonic soot blowers, steel ball soot blowers, shock soot blowers, etc.The media used by the sootblower include superheated steam (some use saturated steam, which is ineffective), compressed air, gas, steel balls, etc.

1. Active anti-fouling measures: Design: 1. Large enough furnace combustion space.The furnace adopts a full-membrane wall welded structure, and the height of the furnace is higher than that of the traditional coal furnace. The large enough furnace space can ensure the primary burnout rate of biomass fuel in the furnace; 2. Safe combustion temperature.The furnace combustion temperature control is designed to be between 700-800 °C to prevent fuel coking.3. Multi-point ash hoppers are designed to facilitate settlement: ash cleaning hoppers are set up in the furnace area, turning area, and convection area.4. When the convection heating surface is designed, the pitch is enlarged, which is 1 times larger than that of the traditional boiler: ①The evaporators are arranged in series, and the larger horizontal pitch is designed to reduce the ash accumulation; ②The economizer, The single pipe circles are arranged in series, and the larger lateral pitch is designed to reduce the accumulation of dust.③The air preheaters are arranged in series, and the horizontal tubular air preheaters have a large horizontal pitch to prevent dust accumulation.④Soot blowers are installed on the heating surfaces of the convection pipe, economizer and air preheater respectively.Installation: strictly control the pipe

There are three main reducing agents in the denitration system: liquid ammonia, ammonia water and urea. The choice of the reducing agent is one of the main factors affecting the denitration efficiency and operating economy.Most of the power plants use urea, and a small part is ammonia water. Some chemical plants or power plants with rich management experience use liquid ammonia.At present, for some small industrial circulating fluidized bed boilers for steam supply and heating, when designing the system of the Design Institute, the storage safety of ammonia water is relatively strict, and most of the reducing agents use urea.

Reply: SCR is the abbreviation of Selective Catalytic Reduction. Under the action of catalyst, NOx in flue gas is reduced to N2 and H2O by injecting ammonia.The main components of the catalyst are TiO2 and V2O5.SNCR is the abbreviation of selective non-catalytic reduction. The reducing agent containing NH3 group is sprayed into the furnace temperature range of 800-950 ℃, and the reducing agent is rapidly thermally decomposed into NH3, which can be directly reacted with NOx in flue gas without catalyst catalysis. The reaction produces N2

1. Welding materials for welding pressure vessels include electrodes, wires, steel strips, fluxes, gases, electrodes and gaskets.2. Selection principle of welding materials: According to the chemical composition, mechanical properties and welding performance of the base metal, and combined with the structural characteristics, operating conditions, welding methods and manufacturing processes of the pressure vessel, the welding materials are selected comprehensively, for example: ① Stress and pressure welding For joints, firstly, the welding materials should be selected according to the principle of joint strength; ②For the welding structure working at low temperature, the low-temperature toughness of each area of ​​the joint should be ensured first, which is more important than the strength of the joint; ③For containers with only corrosion tendency, first ensure the container Corrosion resistance of the parts where the inner wall is in contact with the medium; ④ Secondly, consider the processing technology of the welded structure, such as shearing, cold stamping, cold coiling, hot coiling and the influence of various heat treatment processes on the joint performance (cold stamping, shearing and cooling Coiling and other processes require welding joints to have high plastic deformation capacity; while hot coiling and heat treatment processes require joints

①Normalizing is a method of metal heat treatment. It heats the steel to a certain temperature and keeps it warm, and then cools it in the air to obtain a heat treatment process that is close to a balanced structure. The function is to improve the mechanical properties of the steel.②The normalizing heat treatment of Q345R steel plate is to heat the steel plate to a temperature slightly higher than the Ac3 transformation point (usually the temperature is 890℃~950℃) after the steel plate is rolled, stay at this temperature for a short time and then cool it in still air.Normalizing rolling of Q345R steel plate is a rolling method of rolling at normalizing temperature (generally, rolling starts at 1100℃~1200℃, and the final deformation is controlled above 850℃), which can make the state of the material and the specified value of mechanical properties. Same as normalizing heat treatment.③ Therefore, normalizing rolling actually obtains the microstructure and mechanical properties of normalizing heat treatment through precise temperature-controlled rolling (including final rolling deformation).

The phenomenon of boiler steam with water is a normal phenomenon in steam boilers.According to the provisions of JB/T10094 "General Technical Conditions for Industrial Boilers", the steam humidity of saturated steam boilers is not more than 3%, which is qualified, but the excessive amount of water must be treated.If the following phenomenon occurs, it should be caused by excessive steaming water.The boiler feed water volume is much larger than the boiler outlet steam volume, the boiler feed water pump is fully open at the power frequency, the boiler water level continues to drop, a large amount of water flows out of the trap at the sub-drum, and the steam pipeline vibrates in severe cases.Cause analysis: ① Check whether the device in the pot (steam-water separator) is manufactured incorrectly.② Check whether the boiler water is qualified (whether the salt content of the boiler water exceeds the standard).③ Check the operation record of the boiler and understand the steam usage of the owner, whether there is excessive fluctuation in the compliance of steam usage and sudden surge in load.④Whether the water level of the boiler is normal, and the water level of the boiler is kept too high.Beyond the allowable variation range, the accident state false water level.2. WNS

The single-impulse water level automatic adjustment system is the simplest adjustment method. It adjusts the opening of the feed water control valve according to the water level deviation of the steam drum.The advantage is that the adjustment is simple, and only one water level signal is used as the adjustment amount.The main disadvantage of the single-impulse water level adjustment method is that when the evaporation or steam pressure changes suddenly, the steam content in the boiler water will change rapidly, resulting in a false water level in the boiler drum, resulting in misadjustment of the feed water control valve.Therefore, single-impulse regulation is generally used for small-capacity boilers with relatively stable loads.The three-impulse water level automatic adjustment system is a relatively complete adjustment method. In addition to the drum water level signal, the system also includes steam flow and feed water flow.The water level of the steam drum is the main signal; the steam flow rate is the feedforward signal. Due to the existence of the feedforward signal, it can effectively prevent the malfunction of the regulator caused by "false water level", and improve the adjustment quality under the disturbance of evaporation or steam pressure. ; The feed water flow signal is the feedback signal of the medium, which can overcome the feed water

In the process of boiler water level control, the adjustment method in which the drum water level is used as the feedback signal is called the single-impulse adjustment of the boiler water level.Single-impulse water level control is the simplest and most basic form of automatic control of boiler drum water level.The three-impulse water level adjustment is in the process of automatic water level control, according to the three impulses of the drum water level, feed water flow, and steam flow through PID calculation to adjust the opening of the feed water valve, so as to achieve the purpose of automatic control of the feed water flow.Three-impulse regulation is actually a cascade control system with a feedforward signal.The liquid level controller and the flow controller constitute a cascade control system.Drum level is the primary variable and feed water flow is the secondary variable.The introduction of secondary variables enables the system to have a strong ability to overcome fluctuations in feedwater pressure (flow).The signal of the steam flow is introduced as a feedforward signal.Because the fluctuation of the steam flow is a factor that causes the change of the liquid level in the steam drum, it is a disturbance effect. When the steam flow fluctuates, it is introduced by measuring