scholarly journals USE AND DISPOSAL OF ACIDIC WATER CONDENSATE FROM GAS-FIRED BOILER UNITS

2021 ◽  
Vol 4 (164) ◽  
pp. 24-30
Author(s):  
N. Fialko ◽  
R. Navrodska ◽  
G. Gnedash ◽  
M. Novakivskii ◽  
G. Sbrodova

During operation in boiler units of modern condensing boilers or modernization of old-style boilers, water condensate is formed due to heat-recovery equipment in the mode of cooling exhaust-gases below the dew point of water vapor. At natural gas is burned in equipment, the range of values of the pH value of the condensate is within the range of 3 ÷ 6. In this connection, the problem arises of the useful use of this condensate or its safe drainage into the sewer network. At useful use, the resulting condensate can be used for the needs of the boiler units (for washing boilers, in chemical water-purification systems) or outside the boiler house (for laundries, greenhouses, swimming pools, etc.). In the case of condensate drainage into the city sewer network, as a rule, its preliminary decarbonization is required. This is a necessary environmental measure and operational standard to protect the sewer network and related equipment, including treatment facilities, from premature wear. Among the directions of condensate decarbonization known in Ukraine, the most common are: - decarbonization by degassing by the contact method, which consists in removing CO2 from the heated solution by blowing air in the nozzle layer (ceramic or plastic), through which condensate flows. Degassing occurs due to the instability of the H2CO3 compound, which, when heated, easily decomposes into H2O and CO2; - chemical decarbonization, by combining carbon dioxide in an insoluble compound with various reagents, which are added to the container using a dispenser; - decarbonization by passing the condensate through a granular filter containing calcium carbonate, such as marble chips or lime. Removal of carbonic acid from condensate during filtration in a layer of marble chips is seen as the simplest method of decarbonization of water condensate from those considered. On the basis of this method of decarbonization, the authors propose a technical solution for the developed neutralizer with a description of its design and operating principle. The paper presents the results of calculated studies of the volumes of formed condensate and an example of its safe use in the case of modernization of a gas-fired water-heating boiler with a nominal thermal power of 1 MW by a heat-recovery system with simple or complex use of heat. It is shown that when using modern heat-recovery technologies in gas-fired boiler houses, there are different circuit and technical solutions for possible useful use or safe evacuation of acidic condensate formed during the implementation of these technologies. In cases where it is advisable to neutralize this condensate, there are effective methods for its decarbonization and appropriate equipment.

Author(s):  
Nataliia Fialko ◽  
◽  
Raisa Navrodska ◽  
Georgii Gnedash ◽  
Svitlana Shevchuk ◽  
...  

The calculation and analysis of the complex heat-recovery system for heating by warmth of exhaust-gases from a boiler unit several heattransfer agents for the needs of the boiler house, namely, return heat-network water, combustion air and raw water for chemical water-purification system have been carried out. Results of researches have confirmed high efficiency of the offered technical solution.


Author(s):  
Emanuele Martelli ◽  
Thomas G. Kreutz ◽  
Manuele Gatti ◽  
Paolo Chiesa ◽  
Stefano Consonni

In this work, the “HRSC Optimizer”, a recently developed optimization methodology for the design of Heat Recovery Steam Cycles (HRSCs), Steam Generators (HRSGs) and boilers, is applied to the design of steam cycles for three interesting coal fired, gasification based, plants with CO2 capture: a Fischer-Tropsch (FT) synthesis process with high recycle fraction of the unconverted FT gases (CTL-RC-CCS), a FT synthesis process with once-through reactor (CTL-OT-CCS), and an Integrated Gasification Combined Cycle (IGCC-CCS) based on the same technologies. The analysis reveals that designing efficient HRSCs for the IGCC and the once-through FT plant is relatively straightforward, while designing the HRSC for plant CTL-RC-CCS is very challenging because the recoverable thermal power is concentrated at low temperatures (i.e., below 260 °C) and only a small fraction can be used to superheat steam. As a consequence of the improved heat integration, the electric efficiency of the three plants is increased by about 2 percentage points with respect to the solutions previously published.


2022 ◽  
Vol 1 (15) ◽  
pp. 171-174
Author(s):  
Andrey Savenkov ◽  
Viktorya Kolomiets

The article considers a technical solution for the introduction of pozzolan additives into the cement after grinding clinker. Such additives are the fly ash of the CHP and ash from the ash dump. The use of ash in the composition of cement reduces its cost and energy intensity of its production


Author(s):  
Fred Betz ◽  
Chris Damm ◽  
David Archer ◽  
Brian Goodwin

Carnegie Mellon University’s departments of Architecture and Mechanical Engineering have teamed with Milwaukee School of Engineering’s Mechanical Engineering department to design and install a biodiesel fueled engine-generator with heat recovery equipment to supply electric and thermal power to an office building on campus, the Intelligent Workplace (IW). The installation was completed in early September 2007, and is currently being commissioned. Full scale testing will begin in early 2008. The turbocharged diesel engine-generator set is operated in parallel with the local electric utility and the campus steam grid. The system is capable of generating 25 kW of electric power while providing 18 kW of thermal power in the form of steam from an exhaust gas boiler. The steam is delivered to a double-effect Li-Br absorption chiller, which supplies chilled water to the IW for space cooling in the summer or hot water for space heating in the winter. Furthermore, the steam can be delivered to the campus steam grid during the fall and spring when neither heating nor cooling is required in the IW. Additionally, thermal energy will be recovered from the coolant to provide hot water for space heating in the winter, and for regenerating a solid desiccant dehumidification ventilation system in summer. All relevant temperatures, pressures, and flows for these systems are monitored via a building automation system. Pressure versus time measurements can be recorded in each cylinder of the engine. Emissions of nitric oxide (NO), nitrous oxide (NO2), Particulate Matter (PM), and carbon dioxide (CO2) are also monitored. Upon completion of this installation and the system performance testing, the operation of the engine generator with its heat recovery components will be integrated with the other HVAC components of the IW including a parabolic trough solar thermal driven LiBr absorption chiller, a solid desiccant dehumidification ventilation system, and multiple types of fan coils and radiant heating and cooling devices. This energy supply system is expected to reduce the IW’s primary energy consumption by half in addition to the 75% energy savings already realized as compared to the average US office space.


Author(s):  
Helen Skop ◽  
James Pezzuto ◽  
Valeriy G. Oleynikov-White ◽  
John F. Cavallo ◽  
Robert Fesjian

The baking industry is considered as one of the major energy consuming food industries in North America. More than 40% of bakery fuel consumption is used to evaporate water in the processes [1]. In addition to the baking process’ vapor the oven stack gas contains water vapor from combustion products. Overall the content of water vapor in the typical oven stack gas is about 20% by volume. Most bakeries waste this vapor and its latent heat. Bakeries’ ovens have wide diversity in power and design. Off-the-shelve heat exchangers are not considered as cost effective equipment for stack gas cooling below gas’ dew point temperature. At typical oven stack gas composition water vapor condensation begins to condense at about 72° C. Not using the latent heat of stack water vapor and the heat from gas cooling from dew point temperature to ambient temperature results in low effectiveness of waste heat recovery. Mainly the effect from the recovery of stack gas cooling prior to condensation is considered as non cost effective and waste heat recovery is neglected.


2018 ◽  
Vol 245 ◽  
pp. 07014 ◽  
Author(s):  
Evgeny Ibragimov ◽  
Sergei Cherkasov

The article presents data on the calculated values of improving the efficiency of fuel use at the thermal power plant as a result of the introduction of a technical solution for cooling the flue gases of boilers to the lowest possible temperature under the conditions of safe operation of reinforced concrete and brick chimneys with a constant value of the flue gas temperature, when changing the operating mode of the boiler.


2014 ◽  
Vol 1070-1072 ◽  
pp. 343-346
Author(s):  
Zeng Hong Xiao ◽  
Xing Lu Hua

As wind power integration is scaled up year by year, the problem of abandoned wind electricity has become increasingly severe, and thus caused serious waste of energy. To solve the problem of abandoned wind electricity, this paper tries to heat power plant’s back water in electric boiler to absorb abandoned wind electricity. Taking a thermal power plant for example, the application of electric boiler in backwater system can bring great economic benefits and environmental benefits, and provide a reasonable way and solution for the use of abandoned wind electricity.


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