In-line Heater Research Articles

Research on Water System Inline Heater Heating Performance Simulation of Civil Aircraft

The water system in civil aircraft is indispensable and important. During the design of the water system, cold weather is a severe working condition, which will cause the water system to freeze and lose water supply function, so the heating and anti-freezing design of the water system is necessary. An inline heater is a new heating and anti-freezing equipment for water system pipelines, with the advantage of convenient installation and high heating efficiency. In this paper, the fluid-solid coupling heat transfer simulation is used to study the heating and anti-freezing effect of the inline heater, considering the influence of the water flow rate and the heater power. Through analysis, increasing the water flow rate can improve the heating efficiency of the inline heater, but it also puts forward a higher heater requirement for the inline heater. With the increase of the heating power of the inline heater, its heat utilization rate is constantly decreasing, so blindly increasing the heating power can not significantly improve the heating and anti-freezing performance. This study can guide the water system inline heater design of civil aircraft.

Synaptic GABAergic transmission in the central amygdala (CeA) of rats depends on slice preparation and recording conditions.

The central nucleus of the amygdala (CeA) is a primarily GABAergic brain region implicated in stress and addictive disorders. Using in vitro slice electrophysiology, many studies measure GABAergic neurotransmission to evaluate the impact of experimental manipulations on inhibitory tone in the CeA, as a measure of alterations in CeA activity and function. In a recent study, we reported spontaneous inhibitory postsynaptic current (sIPSC) frequencies higher than those typically reported in CeA neurons in the literature, despite utilizing similar recording protocols and internal recording solutions. The purpose of this study was to systematically evaluate two common methods of slice preparation, an NMDG‐based aCSF perfusion method and an ice‐cold sucrose solution, as well as the use of an in‐line heater to control recording temperature, on measures of intrinsic excitability and spontaneous inhibitory neurotransmission in CeA neurons. We report that both slice preparation and recording conditions significantly impact spontaneous GABAergic transmission in CeA neurons, and that recording temperature, but not slicing solution, alters measures of intrinsic excitability in CeA neurons. Bath application of corticotropin‐releasing factor (CRF) increased sIPSC frequency under all conditions, but the magnitude of this effect was significantly different across recording conditions that elicited different baseline GABAergic transmission. Furthermore, CRF effects on synaptic transmission differed according to data reporting methods (i.e., raw vs. normalized data), which is important to consider in relation to baseline synaptic transmission values. These studies highlight the impact of experimental conditions and data reporting methods on neuronal excitability and synaptic transmission in the CeA.

Nutritional Utilization of Modified Carinata Brassica carinata Meals in Sunshine Bass Diets

AbstractLow amounts (approximately ≤ 10%) of raw carinata Brassica carinata meals are used in animal diets due to the negative effects of antinutrients, mainly glucosinolates. We processed carinata meal by aerobic conversion followed with a single wash (ACCM). Another portion of carinata meal was double‐washed without aerobic conversion (WCM). The objective of this study was to determine if sunshine bass (female White Bass Morone chrysops × male Striped Bass M. saxatilis) fed diets containing low (20%) animal meals could tolerate up to 30% of ACCM or 30% of WCM. Twenty randomly selected sunshine bass (19.2 ± 0.08 g) were stocked in each tank (106 L) of a 32‐tank recirculating aquaculture system, with temperature maintained at 25.6 ± 0.7°C using an inline heater. Seven and six replicates were used for the reference and test diets (10% or 30% ACCM or 30% WCM), respectively, and the fish were cultured for 106 d. Growth improved with increasing levels of processed carinata meals in diets. Survival (>99%) was similar among dietary treatments. Consumption of 30% ACCM and 30% WCM diets was higher than for the reference diet. Feed conversion ratio improved in the WCM dietary treatment and was associated with a better protein efficiency ratio and apparent net protein utilization. Protein deposition was highest in sunshine bass fed 30% of processed carinata meals. Whole‐body protein also increased with increasing processed carinata meals in diets. Sunshine bass fed 30% WCM had lower liver weights and were in better condition than sunshine bass fed other diets. Hematocrit was high in sunshine bass fed ACCM diets. Although carinata meal is high in iron, the single wash in ACCM processing likely removed less iron than the two washes in WCM processing. Hemoglobin contents of sunshine bass were also increased by ACCM but not by WCM. Our results demonstrate that high levels of even moderately processed carinata meal (WCM) can be tolerated in fish diets without affecting fish performance.

Wind Turbine Electrical Energy Supply System for Oil Well Heating

In this article, the authors reviewed a new technology to prevent the formation of asphalt-resin-paraffin deposits by the thermal method of electrothermal impact on the oil wellbore shaft using a wind-electric installation as an autonomous power source. The advantage of this thermal stimulation technique lies in its continuous nature, which will allow keeping the clear opening of the tubing constant. The scheme of the autonomous system for down-hole electric heating of oil is presented. A tubular or induction heater can serve as an electric heating element placed in the well. The heating element of the system can be used in the wells exploited by freeflow, gas lift and mechanized methods, while its installation does not require an overhaul. The paraffin oil saturation temperature and temperature distribution over the depth of the well were defined. The amount of heat, which must be transferred to the oil mixture in the tubing in order to ensure effective operation of the well, taking into account the dynamic state of the system, is calculated. The optimal depth of the heating element's location in the well and its power was determined. The calculation of the required power for wind-electric installation to maintain the set temperature in the wellbore was performed. Having conducted the studies, it was revealed that in order to prevent the asphalt-resin-paraffin deposits formation on the tubing walls of oil wells, it is expedient to use the in-line heater, which maintains the average steady-state temperature along the wellbore and at the wellhead above the initial crystallization point of the asphaltresin-paraffin deposits. The application of the developed electrothermal system is relevant in the conditions of formation of asphalt-resin-paraffin deposits in the wellbore shaft at the fields, which do not have a connection to the centralized power grid.

A novel hybrid renewable solar energy solution for continuous heat and power supply to standalone-alone applications with ultimate reliability and cost effectiveness

This study investigates an integrated energy system designed to supply 100% heat and power to a remote application, renewably. The system comprises a solar photovoltaic (PV) system with hydrogen-based energy storage (SH), a fuel cell heat recovery arrangement, an electric inline heater (powered by the PVs), and a solar thermal system (ST), altogether operating as a renewable combined heat and power solution. A theoretical simulation model is developed in MATLAB to conduct this study. The addition of the inline heater (powered by the PVs) resulted in improving the overall reliability of this integrated renewable energy arrangement from ∼95% to 100% with no additional costs. Additionally, the system is competitive against diesel generator (for power supply) and gas hot water system that is mostly used conventionally in remote areas.

Thermal Heating Induced Fractionation Effect on δ15N Measurements (Using Continuous Flow Isotope Ratio Mass-Spectrometry) for Samples Containing Lower N Contents

Simultaneous measurements of stable isotopes of Nitrogen (N), Carbon (C) and Sulfur (S) in a single aliquot of sample using stable isotope mass spectrometry coupled with elemental analyzer (EA) in a continuous flow mode has provided added advantages for stable isotopic data community scientifically as well as economically. For NCS isotopic measurements, certain configurational changes were adapted in the EA setup such as (1) introduction of ‘purge and trap columns’ for adsorbing and desorbing analyte CO2 and SO2, and (2) introduction of in-line ring heater to cover for the entire passage between combustion and reduction reactor to prevent any condensation of analyte gases. These modifications were made to achieve necessary accuracy and precision NCS isotopic measurements. However, the presence of in-line ring heater appears to have an influence on δ15N measurements especially for samples containing lower N amounts (≤2 μmoles). We compared δ15N measurements in both NCS and NC modes by reconfiguring same EA (Vario Pyrocube) connected with Isoprime mass spectrometer with wide range variability in N content. We observed a decreasing pattern in δ15N values with increasing N contents (till the true δ15N value is approached), which is an opposite trend compared to that typically observed with the NC mode of EA setup. We surmise thermal heating of the passage from the combustion and reduction reactors is most likely responsible for the observed pattern. Measured δ15N values for samples containing lower N (≤2 μmoles), however, could be corrected using appropriate correction procedure.

Study of Fuel Composition, Burner Material, and Tip Temperature Effects on Flashback of Enclosed Jet Flame

Abstract Flashback is a key challenge for low NOx premixed combustion of high hydrogen content fuels. Previous work on jet burner configurations has systematically investigated the impact of fuel composition on flashback propensity, and noted that burner tip temperature played an important role on flashback, yet did not quantify any specific effect (Shaffer, B., Duan, Z., and McDonell, V., 2013, “Study of Fuel Composition Effects on Flashback Using a Confined Jet Flame Burner,” ASME J. Eng. Gas Turb. Power, 135(1), p. 011502). The present work further investigates the coupling of flashback with burner tip temperature and leads to models for flashback propensity as a function of parameters studied. To achieve this, a jet burner configuration with interchangeable burner materials was developed along with automated flashback detection and rim temperature monitoring. An inline heater provides preheated air up to 810 K. Key observations include that for a given condition, tip temperature of a quartz burner at flashback is higher than that of a stainless burner. As a result, the flashback propensity of a quartz tube is about double of that of a stainless tube. A polynomial model based on analysis of variance is presented and shows that, if the tip temperature is introduced as a parameter, better correlations result. A physical model is developed and illustrates that the critical velocity gradient is proportional to the laminar flame speed computed using the measured tip temperature. The addition of multiple parameters further refined the prediction of the flashback propensity, and the effects of materials are discussed qualitatively using a simple heat transfer analysis.

Exposure to cocaine regulates inhibitory synaptic transmission from the ventral tegmental area to the nucleus accumbens

Synaptic projections from the ventral tegmental area (VTA) to the nucleus accumbens (NAc) make up the backbone of the brain reward pathway, a neural circuit that mediates behavioural responses elicited by natural rewards as well as by cocaine and other drugs of abuse. In addition to the well-known modulatory dopaminergic projection, the VTA also provides fast excitatory and inhibitory synaptic input to the NAc, directly regulating NAc medium spiny neurons (MSNs). However, the cellular nature of VTA-to-NAc fast synaptic transmission and its roles in drug-induced adaptations are not well understood. Using viral-mediated in vivo expression of channelrhodopsin 2, the present study dissected fast excitatory and inhibitory synaptic transmission from the VTA to NAc MSNs in rats. Our results suggest that, following repeated exposure to cocaine (15 mg kg(-1) day(-1) × 5 days, i.p., 1 or 21 day withdrawal), a presynaptic enhancement of excitatory transmission and suppression of inhibitory transmission occurred at different withdrawal time points at VTA-to-NAc core synapses. In contrast, no postsynaptic alterations were detected at either type of synapse. These results suggest that changes in VTA-to-NAc fast excitatory and inhibitory synaptic transmissions may contribute to cocaine-induced alteration of the brain reward circuitry.

Kv2 channels regulate firing rate in pyramidal neurons from rat sensorimotor cortex

The largest outward potassium current in the soma of neocortical pyramidal neurons is due to channels containing Kv2.1 α subunits. These channels have been implicated in cellular responses to seizures and ischaemia, mechanisms for intrinsic plasticity and cell death, and responsiveness to anaesthetic agents. Despite their abundance, knowledge of the function of these delayed rectifier channels has been limited by the lack of specific pharmacological agents. To test for functional roles of Kv2 channels in pyramidal cells from somatosensory or motor cortex of rats (layers 2/3 or 5), we transfected cortical neurons with DNA for a Kv2.1 pore mutant (Kv2.1W365C/Y380T: Kv2.1 DN) in an organotypic culture model to manipulate channel expression. Slices were obtained from rats at postnatal days (P7-P14) and maintained in organotypic culture. We used biolistic methods to transfect neurons with gold 'bullets' coated with DNA for the Kv2.1 DN and green fluorescent protein (GFP), GFP alone, or wild type (WT) Kv2.1 plus GFP. Cells that fluoresced green, contained a bullet and responded to positive or negative pressure from the recording pipette were considered to be transfected cells. In each slice, we recorded from a transfected cell and a control non-transfected cell from the same layer and area. Whole-cell voltage-clamp recordings obtained after 3-7 days in culture showed that cells transfected with the Kv2.1 DN had a significant reduction in outward current (∼45% decrease in the total current density measured 200 ms after onset of a voltage step from -78 to -2 mV). Transfection with GFP alone did not affect current amplitude and overexpression of the Kv2.1 WT resulted in greatly increased currents. Current-clamp experiments were used to assess the functional consequences of manipulation of Kv2.1 expression. The results suggest roles for Kv2 channels in controlling membrane potential during the interspike interval (ISI), firing rate, spike frequency adaptation (SFA) and the steady-state gain of firing. Specifically, firing rate and gain were reduced in the Kv2.1 DN cells. The most parsimonious explanation for the effects on firing is that in the absence of Kv2 channels, the membrane remains depolarized during the ISIs, preventing recovery of Na(+) channels from inactivation. Depolarization and the number of inactivated Na(+) channels would build with successive spikes, resulting in slower firing and enhanced spike frequency adaptation in the Kv2.1 DN cells.

Experimental Study of the Injection System for CO2 Geologic Storage Demonstration

The worldwide issue of greenhouse gas reduction has recently drawn great attention to carbon capture and storage (CCS). Almost CCS studies have been focused in the capture technology of carbon dioxide and the geological investigation for underground storage. The study of mechanical injection system for carbon dioxide has not implemented nearly. We are intended to develop a ground system for underground injection of carbon dioxide. In this study, we made lab-scale underground injection system and implemented injection simulation test experimentally. The 10,000 ton/year pilot plant for geological storage of carbon dioxide will be designed on the base of these test results. Major components of the lab-scale underground injection system include a pressure pump and an in-line heater to bring liquid carbon dioxide into its supercritical state. Test results assure that this system readily achieves the designed injection pressure and temperature, showing satisfactory control performance.

MSWI super heater tube bundle: Particle impaction efficiency and size distribution

Particle impaction in an in-line super heater tube bundle has been investigated. By using direct numerical simulations for the fluid flow, inertial particles coupled to the fluid through the classical Stokes' drag law have been tracked. Focus has been on the effect of flow velocity, and it is shown that decreasing the flow velocity will drastically decrease the impaction efficiency for some particle radii. Fouling due to the inertial impaction of such particles is consequently very sensitive to the fluid velocity. The results are subsequently combined with particle size distribution measurements from the municipal solid waste incinerator (MSWI) of GKS in Schweinfurt, Germany. Impacting mass fluxes both on the front and back sides of the tubes in the super heater tube bundle are calculated, and it is found that the largest part of the mass impaction stems from particles with diameters in the range from 5×10−5m to 7×10−4m.

Enhancement of pool boiling critical heat flux in dielectric liquids by microporous coatings

An experimental investigation into the effects of pressure and subcooling on the pool boiling critical heat flux from a bare silicon chip-like heater and from a silicon heater coated with microporous layers, is reported. The dual inline heater package was immersed in FC-72, a dielectric fluid, and the experiments were performed in the horizontal orientation, with subcooling varying between 0 K and 72 K, and the pressure between 101.3 kPa and 303.9 kPa. The maximum CHF values on the diamond-base microporous-coated silicon heater were found to reach 47 W/cm 2, at 3 atm and nearly 50 K of subcooling, and to provide an average enhancement of approximately 60% over the values attained with un-treated silicon surfaces. An available CHF correlation, with a reported standard deviation of 12.5% for un-treated surfaces over a large range of pressures, subcoolings, and surface conditions, was shown to predict the pressure and subcooling effects on CHF from the surface-enhanced chip with a standard deviation of 12%.

Performance of a venturi flow meter in two-phase helium flow

The performance of a venturi flow meter in vertical and horizontal two-phase helium flow is reported. In both flow configurations, tests were conducted by connecting two identical Venturis of 2.29 mm throat and 4.57 mm inlet diameters in series with a two-phase helium flow loop driven by a single-stroke bellows pump. With one venturi operating in single-phase liquid helium and one in two-phase helium, as controlled by an in-line heater, the ratio of the pressure drop across the two venturis is found to be well correlated with vapour quality. Vertical flow tests were performed under both forced flow and natural circulating flow conditions at 1.0 atm and at mass flow rates ranging from 1.0 to 2.5 g s −1. Horizontal flow tests were conducted at mass flow rates ranging from 0.5 to 2.0 g s −1 and under system pressures between 0.65 and 1.2 atm. Within the parameter range covered in the present study, the performance of the venturi flow meter in two-phase helium flows can be well described by the homogeneous model regardless of the flow orientation.

Molecular weight distribution of polyphenylene sulfide by high temperature gel permeation chromatography

AbstractPoly(phenylene sulfide) (PPS) has been characterized using a novel high temperature gel permeation chromatograph (GPC). Samples were injected in slurry form at ambient temperature, and redissolved by an in‐line precolumn heater at 250°C. A viscometer consisting of a capillary tube with inlet and outlet taps connected to a sensitive differential pressure transducer was used as sole detector, with deflections converted to concentration using the column calibration. Columns and viscometer were operated at 210°C. Universal calibration was carried out using intrinsic viscosity/molecular weight relations for polystyrene and PPS, determined by light scattering. Satisfactory operation was confirmed by agreement between intrinsic viscosity calculated from GPC with independently measured values, and comparisons with melt flow data. Samples of PPS tested were found to be of relatively narrow distribution, with Mw/Mn typically less than two.