Application of Controllable Splitting Grouting Technology in Loess Foundation Reinforcement

Taking the foundation settlement accident of a large heating boiler foundation in a city in collapsible loess area as an example, controllable splitting grouting can be achieved by controlling the grouting pressure, grouting pipe opening form, grouting volume and grouting method etc., so as to stabilize foundation settlement and improve foundation bearing capacity, for the boiler with large uneven settlement, for boilers with large uneven settlement, quicklime piles are used to jack up the foundation after splitting grouting to stabilize the foundation, the foundation is lifted with quicklime piles after splitting grouting to stabilize the foundation. The results show that the grouting amount of soil is within the design range, the grout splits in the soil several times to form a slurry vein, the settlement is stable after boiler reinforcement, the quicklime method can jack up the foundation and reduce the uneven settlement of the foundation, and the use of controllable splitting grouting can basically eliminate the slight collapsibility grade loess, which provides a new idea for solving the similar problem of uneven settlement of collapsible loess foundation buildings.

Prevention of condensation in chimneys of boiler plants with heat-recovery systems

The results of studies of the effectiveness of using the air method of preventing condensation formation in the gas-exhaust ducts for anticorrosive protection of chimneys of gas-fired heating boiler plants are presented. This method is used in heat-recovery systems of boiler plants, characterized by deep cooling of gases (below the dew point temperature of water vapor contained in exhaust-gases). The essence of this method is to change the thermal and humidity characteristics of exhaust-gases after heat-recovery by mixing dry and heated air in front of the chimney. Schematic solutions of heat-recovery systems using two options for using the air method are presented. The first option corresponds to the use of the air method when mixing air from the heater of boiler plant. In the second option, for the implementation of the air method, air heated in the heat-recovery system itself is used. To assess the efficiency of the air method, computational studies were carried out to determine the thermal and moisture characteristics of flue gases at the mouth of different types of chimneys under different operating modes of the boiler during the heating period. The studies were carried out for two proposed options for using the air method when using air with a change in its temperature over a wide range. The values of the dew point of the flue gases at the mouth of the chimney and the temperature of its inner surface were calculated at various proportions of the mixed air. The parameters of flue gases and mixed air were determined, ensuring the absence of condensation in the chimneys. Based on the values of the obtained parameters, a comparative analysis of the effectiveness of the considered options for using the air method was carried out. It is shown that for heating boilers the use of this method is the most effective in complex heat-recovery systems when using recovered heat for heating return heat-network water and combustion air. Key words: gas-fired boilers, exhaust-gases, deep cooling, air method, thermal and humidity condition, chimney, anticorrosive protection

Operational tests of an electrostatic precipitator reducing low dust emission from solid fuels combustion

The article presents the continuation of the research aimed at designing, manufacturing and selecting the operating parameters of the electrostatic precipitator for household applications. The tests were carried out in the laboratory and real conditions. The object of the research was a pre-production prototype of the electrostatic precipitator installed in the flue gas duct of a single-family building. The source of exhaust gases was a coal-fired, low-temperature water heating boiler with a nominal power of 21 kW (old generation boiler-year of production: 2007). The obtained results showed that the adopted design of the electrostatic precipitator enables the reduction of dust emissions generated in the combustion of solid fuels in households at relatively low operating costs.

ABOUT THE POTENTIAL OF CONDENSATION HEAT USAGE IN MEAN OF SURFACE CONDENSATION HEAT EXCHANGERS FORHEATING BOILER PLANTS

The article considers the potential possibility of using the condensation heat of water vapor from flue gases for various types of fuel and variants of coolants. This technical solution allow to use additional fuel heat, and thereby reduce fuel consumption in the production of thermal energy. The results obtained allow us to analyse the applicability of the condensation cooling technology for heating boiler plants.

Single case study photovoltaic panels within water heating system

The submitted article offers one of the possible options of a usage of photovoltaic panels for a domestic hot water preparation with an option to extra heating a heating system, and following recalculation of a produced electric energy amount in regards of a total return of the assembled system. An electric heating boiler combined with a heating option working on solid propellant was chosen for the experiment. The most frequently used combined electric storage tank was chosen as a classic option to heat domestic hot water.

A Philosophical Treatise and Educational Aspects on Fuzzy Control

Fuzzy Logic has found nowadays many applications to almost all sectors of human activity, withfuzzy control being one of the most important such applications. A control system regulates the behavior of adevice or another system with the help of a feedback controller. A fuzzy control system is a control system thatanalyses the input data in terms of variables which take continuous values in the interval [0, 1]. The presentarticle studies in detail the operation of fuzzy control systems and illustrates it by presenting an exampleof controlling a building’s central heating boiler.