Impact of Waste Heat Recovery of Chimney Using U-Shaped Pulsating Heat Pipe to Generate Hot Water- Experimental and Environmental Analysis

Many studies have been done on the Pulsating heat pipes (PHP) using energy applications system. In this study a heat exchanger PHP is analyzed. A heat pipe prototype is manufactured for waste heat recovery. The present study experimentally investigated the effect of pulsating heat pipe on the waste heat recovery of the chimney and produce hot water for household consumption. The evaporator is placed in a smoke exhaust duct and the condenser is located in a water chamber in which the smoke heat is transferred through. The results are presented for different heat pipe angles to the horizon from 0 to 90. The PHP is filled 60% by distilled water as operating fluid. The highest hot water temperature in outlet of reservoir was about to 58 oC. Also, The CO2 mitigation and CPH of the waste heat recovery system was equal to 84.82 tons and 0.1$/m3. Moreover, the efficiency is changing from 19% for a horizontal PHP to 54% for a vertical one.

Structure guided engineering of a cold active esterase expands substrate range though a stabilisation mutation that allows access to a buried water chamber

Cold active esterases represent an important class of enzymes capable of undertaking useful chemical transformations at low temperatures. EstN7 from Bacillus cohnii represents a true psychrophilic esterase with a temperature optimum below 20°C. We have recently determined the structure of EstN7 and have used this knowledge to understand substrate specificity and expands its substrate range through protein engineering. Substrate range is determined by a plug at the end of acyl binding pocket that blocks access to a buried water filled cavity, so limiting EstN7 to turnover of C2 and C4 substrates. Data mining revealed a potentially important commercial reaction, conversion of triacetin to only the 1,2-glyceryl diacetate isomer, which the EstN7 was capable of achieving. Residues M187, N211 and W206 were identified as plug residues. M187 was identified as the key plug residue but mutation to alanine destabilised the structure as whole. Another plug mutation, N211A had a stabilising effect on EstN7 and suppressed the destabilising M187A mutation. The M187A-N211A variant had the broadest substrate range, capable of hydrolysing a C8 substrate. Thus, the structure of EstN7 together with focused engineering has provided new insights into the structural stability and substrate specificity that allowed expansion of substrate range.

Results of experimental studies of changes in the level and heating of the main condensate in mixing-type LPH

In the thermal circuits of domestic steam turbines, mixing-type low-pressure heaters (LPH) with free-flow jet water distribution and counter-flow of water and steam are widely used. The choice of the counterflow variant of the media movement ensures the most efficient heat transfer. However, the technical problem of ensuring reliable operation of LPH in the entire range of design loads of TPP and NPP power units is still relevant.During the commissioning and operation of mixing-type LPH in 800÷1200 MW turbines of TPP and NPP, the presence of metal knocks in the zone of the check valve, hydraulic shocks in the heating section were revealed. A priori, these phenomena indicated design flaws in LPH or manufacturing defects in their production. Research carried out by NPO CKTI specialists showed that periodic hydraulic shocks in the heating section and metal knocks occur as a result of uneven distribution around the circumference of the main condensate and steam supply. This leads to a breakdown of the check valve and the destruction of perforated plates and off-design heating of water in the volume of the annular LPH water chamber. To clarify the causes of the damage, develop recommendations for the reconstruction of the apparatus and further account for the design, two series of experimental studies were carried out on mixing-type heaters of 800 MW turbine units PNSV-2000-1 and PNSV-2000-2 manufactured at PJSC Krasny Kotelshchik. The purpose of the experimental studies was to determine the change in the water level in the water chamber and the heating of the main condensate in the elements of the heating compartment during normal operation of the power unit at loads of 400÷850 MW. Based on the results of the research, the method for calculating the mixing-type LPH has been refined, taking into account the revealed non-uniformity of water heating in the water chamber, recommendations for their reconstruction have been developed and implemented.

Analysis on the Influence Mechanism of Cooling Water on Turbocharger and Optimum Coolant Mass Flow Rate Intelligent Prediction

Due to the high speed and high temperature of engine exhaust, the turbocharger bears very high heat load. The heat dissipation of turbocharger is an important factor to determine the service life and performance of turbocharger. In this paper, a mathematical model of the fluid-structure interaction heat transfer of the water-cooled bearing body of turbocharger was established and the cooling performance of a 1.8 L gasoline engine turbocharger was analyzed. The effects of cooling water inlet flow, engine exhaust temperature, cooling water inlet temperature, and wall roughness of cooling water chamber on the cooling performance of important parts of the bearing body were analyzed by the numerical simulation method. In addition, the cooling water flow required by bearing body with a different structure under different working conditions was studied based on the orthogonal test method. The predicted result shows a good agreement with the experiment result, which could provide a reference for relevant production design and cooling strategy. In the range larger than the thickness of laminar flow bottom layer of the cooling water chamber wall, the increase of wall roughness height can enhance the heat transfer between the fluid and the solid.

A simplified numerical and analytical study for assessing the seismic response of a gravity concrete lock

ABSTRACT: This work presents the dynamic response of a lock subjected to the horizontal S0E component of the El Centro earthquake for empty and completely filled water chamber cases, by coupled fluid-structure analysis. Initially, the lock was studied by approximation, considering it similar to the case of a double piston coupled to a two-dimensional acoustic cavity (tank), representing a simplified analytical model of the fluid-structure problem. This analytical formulation can be compared with numerical results, in order to qualify the responses of the ultimate problem to be investigated. In all the analyses performed, modeling and numerical simulations were done using the finite element method (FEM), supported by the commercial software ANSYS.

The effect on the anaesthetised rabbit of warming the breathing circuit with 40°C liquid

During every surgical procedure, one of the aims is to reduce the risk of anaesthesia. Some factors can be influenced, such as core body temperature. The authors wanted to investigate a method that was cheap, efficient and also easy to use in everyday veterinary practice, as well as in more remote settings. The study examined the temperatures of 30 rabbits during inhalational anaesthesia, when using a facemask and T-piece circuit. The rabbits were put in three groups, with two groups inhaling the warmed gas mixture. The inhalational breathing circuit in these two groups was immersed in a 40 ± 1°C heated water chamber. The circuit was 60 cm in the first group and 80 cm in the second group. The third control group inhaled a gas mixture at ambient room temperature. The results indicated that the longer the piece of circuit that was warmed, the less the body temperature of the rabbit dropped. In the control group, at the 40th minute of anaesthesia, the average drop in body temperature was −1.28°C, while in the 60 cm heated group it was −0.65°C, and in the 80 cm heated group it was −0.27°C.

Gas flow in preterm infants treated with bubble CPAP: an observational study

ObjectiveTo measure the nasal gas flow in infants treated with bubble continuous positive airway pressure (CPAP) and compare it with commonly used flows during nasal high flow (nHF) treatment.DesignThis is a prospective, single-centre study. Bubble CPAP pressure was measured at the nasal prongs. Set gas flow was reduced until bubbling in the water chamber just ceased. Set gas flow without bubbling then approximated flow entering the infant’s nose (‘delivered flow’).SettingNeonatal intensive care at The Royal Women’s Hospital, Melbourne, Australia.PatientsClinically stable preterm infants receiving bubble CPAP therapy.Main outcome measureDelivered flow (L/min) when bubbling stopped at a range of clinically set CPAP pressures (cm H2O).ResultsForty-four infants were studied, with a mean (SD) gestational age at birth of 28.4 (2.2) weeks and birth weight of 1154 (419) g. At the time of the study, infants had a median (IQR) age of 4.5 (2–12) days and a mean (SD) weight of 1205 (407) g. Delivered flow ranged from 0.5 to 9.0 L/min, and increased with higher set CPAP pressures (median 3.5 L/min at CPAP 5 cm H2O vs 6.3 L/min at CPAP 8 cm H2O) and heavier weights (median 3.5 L/min in infants <1000 g vs 6.5 L/min for infants >1500 g).ConclusionsNasal gas flows during bubble CPAP in preterm infants are similar to flows used during nHF and increase with higher set bubble CPAP pressures and in larger infants.Trial registration number ACTRN12619000197134.