FEATURES OF WATER TREATMENT FOR BOILER ROOMS

Thousands of medium and low steam boilers and hot water boilers operate in the country's industry, municipal energy and agriculture. Their reliable operation is largely determined by the maintenance of a rational water-chemical regime. The main problems of source water are the presence of dissolved oxygen, iron ions, salts of calcium, and magnesium. The aim of the work is to analyze the existing technologies and equipment for water treatment for different types of boilers. Determination of physicochemical parameters and requirements for source and prepared water. Presentation of new multi-purpose energy-efficient and resource-saving water treatment equipment. The article considers the negative impact of dissolved iron, hardness salts, dissolved gases present in the feed water on the operation of boiler equipment. The main requirements for feed water in terms of hardness, the content of dissolved oxygen, and oils for steam and hot water boilers are given. The mechanism of scale formation is given. The main existing methods of feed water treatment are considered, namely softening on Na-cation exchange resin, liming, softening, and reduction of total salt content on reverse osmosis units, softening, and reduction of total salt content by the sequential passage of water through H, OH-ion exchange filters. A multi-purpose aeration-oxidation setup of rotor type (AORT) is presented, which implements the method of discrete-pulse energy input, on which it is possible to carry out operations to remove iron, manganese, hardness salts, increase pH and degassing from water.

Development of an algorithm of implementation of programs of repair of steam boilers and turbines of TPPs based on technical condition of power equipment

Deterioration and aging of the technical fleet of thermal power facilities lead to an unpredictable shutdowns of power equipment. Therefore, it is necessary to create a special approach in maintenance and repair programs, taking into account the possibility of predicting the moment of onset of the defect, its development, as well as the time of possible equipment failure. The equipment maintenance system used at the enterprises is based on the collection of retrospective data on defects and failures on the main and auxiliary equipment of the TPP and summarizing statistics on identical or similar equipment samples. Analysis of domestic and foreign methods of maintenance and organization of repair, as well as possibility of their application in modern power engineering is given. In order to create an efficient production asset management system, which addresses the problem of finding a balance between the potential risk of losses associated with both the operation of equipment and the cost of correcting defects, new class systems are now used in the software market, which carry out equipment maintenance based on the forecast. In order to optimize the equipment maintenance system and ensure uninterrupted and reliable operation of the equipment at minimum operating costs, as well as to reduce equipment downtime, unscheduled and emergency operations, it is advisable to use a modern approach to manage both reliability and risk, as well as the cost of asset ownership. This will enable to control the economic efficiency of the use of production assets. The necessity of creation of an algorithm of implementation of repair programs of power equipment base on technical condition for its use in digital power systems is shown. An algorithm is proposed for implementing the repair program of power units of electric power plants, including steam boilers and turbines of thermal power plants, differing by taking into account the technical condition of power equipment, which allows recognizing the defect that has appeared, determining the cause of its occurrence, its evolution and the duration of possible equipment failure. In the developed repair maintenance algorithm, it is proposed to make a transition from statistical empirical assessments of the technical condition of the equipment to objective estimates obtained on the basis of automated technical diagnostics systems and predictive analysis of situations.

STUDY OF WATER ECONOMIZERS OF STEAM BOILERS AND DEVELOPMENT OF MEASURES FOR EXTENDING THEIR OPERATION

The operation of the economizer of the P-50 boiler unit, as well as the conditions of its operation have been studied. The economizer is one of the main components of the boiler unit. It works in very difficult conditions. The quality of the feed water supplied to the drum depends on the operation of the economizer. The thermal calculation of steam boiler type P-50 using different values ​​of feed water temperatures at the inlet to the economizer and different coefficients of excess air in the furnace, identified and analyzed factors that negatively affect the operation of the water economizer to conduct a detailed analysis and development of recommendations to improve the operation of the steam boiler as a whole and separately economizing heating surfaces. As a result of the calculations, the dependences of the heat perception of the economizer on the temperature of the feed water at the inlet to the economizer and the dependence of the excess air on the total volume of combustion products are obtained. The paper considers in detail the possible causes of failure of economizers and factors that have a negative impact on the condition of the metal pipes; proposed recommendations that will increase the service life of economizers until the next repair campaign.

Potential of Bagasse as Raw Material for Lignosulfonate Surfactant

Anionic surfactants are generally used in surfactant injections because they are good, resistant in storage and stable. Furthermore, Commercially, anions are produced in the form of carboxylates, sulfates, sulfonates, phosphates, or phosphonates. The surfactants used in the process of implementing Enhanced Oil Recovery (EOR) are generally petroleum-based, such as Petroleum Sulfonate. Therefore, an increase in oil price, leads to an increase in the price of surfactant and the operational costs becomes relatively expensive. Lignosulfonate is a type of anionic surfactant which is made with lignin as raw material. This lignin is found in many plants, including wood stalks, plant leaves, peanut shells, corn cobs, bagasse, empty bunches of oil palm and wheat straw. Based on the results of previous studies, 25% of lignin component was discovered in bagasse. This may be a consideration that there is enough lignin in bagasse to be used as raw material in the production of lignosulfonate vegetable surfactants. Furthermore, lignin from bagasse is used because bagasse is easy to obtain, cheap and an environmental friendly vegetable waste. Currently, bagasse is only used as fuel in steam boilers and papermaking, cement and brick reinforcement, a source of animal feed, bioethanol, activated charcoal as adsorbent and compost fertilizer. This is a consideration to optimize the use of bagasse to become lignosulfonate as an alternative for surfactants in the petroleum sector. The purpose of this study is to show that lignin from bagasse has the potential of becoming a lignosulfonate surfactant. There are several studies that have processed bagasse into sodium lignosulfonate. The component test on the results showed that the surfactant component of sodium lignosulfonate from bagasse was almost the same as the commercial standard lignosulfonate component. Furthermore, the results of the HLB (Hydrophilic–Lipophilic Balance) value test show that the sodium lignosulfonate surfactant from bagasse can function as an emulsion form which is a required parameter for the surfactant injection mechanism. Based on the discussion of the study results, bagasse has the potential as a raw material to be processed into lignosulfonates.

ESTIMATING OF DURABILITY INDEXES OF STRUCTURAL ELEMENTS BASED ON IDENTIFICATION OF THEIR DETERMINISTIC PROPERTIES

Durability indexes are presented as a consequence of some deterministic properties inherent in the system and (or) their elements, and it is proposed to determine the durability indexes on the basis of analysis of these properties. The most important for estimating the durability are properties related to the lifetime, and the deterministic properties basic for determining the indexes of durability, can be represented by the function of the dependence of the lifetime on the parameter defining the operational conditions. Estimating the durability indexes is reduced to identification of the deterministic properties representing the dependence of the lifetime on the parameter defining the operational conditions. An example of estimating the durability of pipes of superheaters of steam boilers demonstrates the proposed approaches with relatively less complexities. This particular example shows that deterministic properties can have a significant influencing on the durability due to significant differences between the density function of the parameter defining the operational conditions and the density function of the lifetime. The proposed approaches can be recommended for use to estimate the durability indexes of unique technical systems, such as high-power steam boilers and nuclear power reactors, which are usually manufactured in single batches, as well as to estimate the durability indexes of any systems at the stage of their development in order to compare the durability of different constructions.

Galvanic Sensor for Detecting Corrosion during Acid Cleaning of Magnetite in Steam Boilers

A simple galvanic sensor was developed to determine the onset of iron corrosion under conditions similar to those used for removing the iron oxide (magnetite) layer from steam boilers with a hy-drochloric acid solution. Since the potentials of magnetite and iron are different, the initiation of the dissolution of the magnetite layer without corroding the base metal can be determined by moni-toring the potential of a sensor made of magnetite layers of different thicknesses that can be placed directly on the iron surface. Moreover, the time at which the addition of corrosion inhibitors is required to protect the base metal can be specified using this sensor. It has been shown that the time required for the iron base metal to start was dependent on the magnetite layer thickness in the sensor. With this sensor, the onset of the steel corrosion during the cleaning can be detected in re-al-time which makes the oxide removal process less harmful to the base metal.