Techno-economic analysis of heat exchangers with parallel helical tube coils

The paper deals with the investment and exploitation costs for shell and tube heat exchangers with parallel helical tube coils. The most common correlations for estimating prices of shell and tube heat exchangers found in open literature were tested using the market data for a comparison and they have shown significant deviations. A new correlation for calculating prices of heat exchangers with helical tubes (when the shell is made of carbon steel and the helical tube of copper) was determined. In addition, the costs of electricity needed to drive pumps, as well as the costs of chemical cleaning of the apparatuses with inhibited mineral acids were estimated

Comparative computation of cylindrical shells loaded by external pressure according to srps and asme standards

This paper give area of application of SRPS M. E2.254:1991 and ASME standards for calculating thickness of cylindrical shell subjected to external pressure. It is shown the design of a vertical cylindrical pressure vessel filled with non-aggressive liquid made of austenitic steel, where it was found that by applying the aforementioned standards, approximately identical value of thickness of the cylindrical shell of the pressure vessel has been obtained

Application and design of an economizer for waste heat recoveryin a co-generation plant

Energy increase cost has required its more effective use. However, many industrial heating processes generate waste energy. Use of waste-heat recovery systems decreases energy consumption. This paper presents case study of waste heat recovering of the exhaust flue gas in a 1415 kWe co-generation plant. This waste heat can be recovered by installing an economizer to heat the condensed and fresh water in thermal degasification unit and reduce steam use for maintaining the temperature of 105 degrees C for oxygen,removal. Design methodology of economizer is presented

Techno-economic analysis of heat exchangers with parallel helical tube coils

U radu su prikazani investicijski i eksploatacijski troškovi kod bubnjastih izmjenjivača topline s paralelnim zavojnim cijevima. Provedena je statistička analiza najčešće rabljenih korelacija iz otvorenih literaturnih izvora za određivanje cijena bubnjastih izmjenjivača topline s tržišnim podacima aparata s kojom je utvrđeno da pokazuju značajna odstupanja i da se ne mogu s dovoljnom pouzdanošću koristiti za navedeni tip aparata. Uspostavljena je nova korelacija za procjenu cijena aparata sa zavojnim cijevima (za slučaj kada je omotač aparata izrađen od ugljičnog čelika, a cijevni snop od bakra). Procijenjeni su troškovi električne energije za pogon pumpi kao i troškovi kemijskog čišćenja aparata inhibiranom klorovodičnom i sumpornom kiselinom.The paper deals with the investment and exploitation costs for shell and tube heat exchangers with parallel helical tube coils. The most common correlations for estimating prices of shell and tube heat exchangers found in open literature were tested using the market data for a comparison and they have shown significant deviations. A new correlation for calculating prices of heat exchangers with helical tubes (when the shell is made of carbon steel and the helical tube of copper) was determined. In addition, the costs of electricity needed to drive pumps, as well as the costs of chemical cleaning of the apparatuses with inhibited mineral acids were estimated

Structural and mechanical properties of different hard welded coatings for impact plate for ventilation mill

Ventilation mill for grinding coal is one of the main steam power plants in the system that makes a significant influence on the level of energy efficiency with its work. Working parts of the device during exploitation are dominantly exposed to intensive abrasive and erosive wear and also to impact loading at elevated temperatures, which can lead to damage and fracture of homogeneous materials, thus shortening their working life. The consequences are the reduction in mill production capacity and its ventilatory effects compared to the projected value, as well as frequent delays due to parts replacements, that significantly affects the productivity, economy and energy-efficiency of the system. In order to determine the optimal technology for revitalization of the damaged impact plates the experimental model-hardfacing was engaged and different technologies and additional materials were used. Three technologies archardfacing were applied (MMA, SMAW and gas welding - G) and eight additional materials with different chemical composition and properties (Fe-Cr-C-Si, Fe-Cr-C-Si-Ti, Fe- C-W-Co-Ni-Si, Fe-Cr-W-B-Nb-Mo-C, W-Fe-C and WC-Ni- Cr-Si-B). The aim of this paper is to make the selection of optimum welding procedures and additional materials and hardfacing technology definition based on the results of structural and mechanical properties of samples of experimental model hardfacing. Cutting the samples for mechanical and structural tests is performed with water jet cutting using hardfaced test plan. Investigation of its macrostructure has been done, diagrams of distributions of hardness have been made, zone of the surface layer and HAZ-a, and the degree of mixing for all hardfaced samples have been defined. In addition, microstructural analyses were obtained with optical (OM) and scanning electron microscopy (SEM). The choice of additional materials and hardfacing procedures which were applied in the hard facing impact plates ventilation mill has been made based on the results of this research paper

Manufacturing costs of gasketed and brazed plate heat exchangers

The paper deals with the investment costs for gasketed and brazed plate heat exchangers. The most common correlations for estimating prices of this types heat exchangers found in open literature were tested using the market data for a comparison and they have shown significant deviations. A new correlation for calculating prices of stainless steel gasketed plate and frame heat exchangers was determined in the form: , while a new correlation for calculating prices of stainless steel brazed apparatus was determined in the following form

Manufacturing costs of shell and tube heat exchangers with helical tube coils

The paper deals with the manufacturing costs for shell and tube heat exchangers with parallel helical tube coils. The most common correlations for estimating prices of shell and tube heat exchangers found in open literature were tested using the market data for a comparison and they have shown significant deviations. A new correlation for calculating prices of heat exchangers with helical tubes (when the shell is made of carbon steel and the helical tube of copper) was determined in the following form

Techno-economic analysis of heat exchangers with parallel helical tube coils

U radu su prikazani investicijski i eksploatacijski troškovi kod bubnjastih izmjenjivača topline s paralelnim zavojnim cijevima. Provedena je statistička analiza najčešće rabljenih korelacija iz otvorenih literaturnih izvora za određivanje cijena bubnjastih izmjenjivača topline s tržišnim podacima aparata s kojom je utvrđeno da pokazuju značajna odstupanja i da se ne mogu s dovoljnom pouzdanošću koristiti za navedeni tip aparata. Uspostavljena je nova korelacija za procjenu cijena aparata sa zavojnim cijevima (za slučaj kada je omotač aparata izrađen od ugljičnog čelika, a cijevni snop od bakra). Procijenjeni su troškovi električne energije za pogon pumpi kao i troškovi kemijskog čišćenja aparata inhibiranom klorovodičnom i sumpornom kiselinom.The paper deals with the investment and exploitation costs for shell and tube heat exchangers with parallel helical tube coils. The most common correlations for estimating prices of shell and tube heat exchangers found in open literature were tested using the market data for a comparison and they have shown significant deviations. A new correlation for calculating prices of heat exchangers with helical tubes (when the shell is made of carbon steel and the helical tube of copper) was determined. In addition, the costs of electricity needed to drive pumps, as well as the costs of chemical cleaning of the apparatuses with inhibited mineral acids were estimated

Water deoxygenation using hollow fiber membrane module with nitrogen as inert gas

A pilot plant scale fiber membrane system was developed for the removal of dissolved oxygen from water via nitrogen vacuum. Feed water was introduced to the shell side; a nitrogen gas was applied to the lumen side, as an inert gas, of the hollow fiber. Outlet concentrations of oxygen in water depend on membrane module, inlet concentrations of oxygen in water, water flow, and nitrogen concentrations in inert gas and nitrogen flow. The effects of nitrogen purity on removal efficiency of dissolved oxygen were investigated. Equations for oxygen concentrations and efficiency due to nitrogen purity have been given