Steam Content Research Articles

Bamboo flattening technology ebables efficient and value-added utilization of bamboo in the manufacture of furniture and engineered composites

Bamboo flattening, a novel and efficient bamboo processing and utilization technology, can effectively flatten bamboo culms into crack-free board. The technology enables the efficient and value-added utilization of bamboo in the manufacture of furniture and engineered composites. In this study, we compared the effects of three types of flattening technologies on the macro-mechanical, macro-physical, micro-morphology, and micro-mechanical properties of untreated, softened a flattened bamboo samples. As expected, the hemicellulose and cellulose concentrations of the saturated steam treated sample (18.05% and 38.9%, respectively) were less than those the untreated sample (21.3% and 40.1%, respectively). Moreover, scanning electron microscopy (SEM) analysis showed that the notched flattening technology (NFT) inserted indents and grooves on the bamboo surface. However, the “non-notched flattening technology (NNFT)” only compressed the bamboo tissue. The flattening process increased the equilibrium moisture content and density of bamboo. The enhanced density, lignin content, and cellulose crystallinity index enhanced the bamboo cell wall properties. The non-notched-flattened bamboo board exhibited a higher cell wall modulus of elasticity and hardness (20.1 and 0.89 GPa, respectively) than the untreated bamboo samples (13.7 and 0.49 GPa, respectively). The enhanced bamboo cell wall mechanical properties of the non-notched-flattened bamboo board. Finally, we explored the practical applications, economic benefits, and limitations of the current “Non-notched bamboo flattening technology”.

Analysis of the Potential for Alternative Fuels Refused Derived Fuel from Waste Briquettes at the Sidoarjo Regency Final Disposal Site

The Griyo Mulyo Jabon Final Waste Processing Site (TPA) in Sidoarjo Regency with a waste generation reached 350 tons/day had the potential to be processed into raw material for Refused Derived Fuel (RDF). RDF fuel had come from waste residue briquettes contained the composition of paper, wood, cloth, rubber, and plastic (4K1P). Briquettes that can be used as raw materials for RDF were those that have characteristics according to SNI standards. This study aimed to determine the percentage of the composition of briquettes that have the potential to produce RDF and the standard quality of the resulting RDF. The reseach was conducted by taking waste samples every week four times with variations in detention time of 2, 4 and 6 hours.a. The method of calculating the value of RDF standard quality was in accordance with SNI 01-6235-2000 with the parameters analyzed were water content, ash content, volatile/steam content and calorific value. The results showed that the best briquette composition produced from 4K1P waste residue was in samples with a composition of 20% wood, 10% paper, 10% rubber/fabric, and 60% plastic. The best quality briquettes with 5.5% moisture content, 4.9% ash content, 15.9% steam content, and calorific value 8996 cal/gram.

Ammonia production from nitrogen-rich biomass gasification: Nitrogen transformation from model amino acids

Ammonia (NH3) is currently being explored as a sustainable energy carrier. Ammonia production from nitrogen-rich biomass gasification provides a sustainable, distributed, and flexible process to efficient storage and conversion of renewable energy. Nitrogen is primarily in the form of proteins (amino acids) in biomass. Three amino acids, glutamic acid (Glu), glycine (Gly), and phenylalanine (Phe), with distinct structures, were screened as N-containing model compounds to assess the effects of operating conditions on nitrogen chemistry. Results indicate that chemical structure has asignificantimpact on thermal decomposition properties and N-conversion selectivity of amino acids. Gly possesses the highest NH3-N yield (∼56.4%), because the simple amino structure easily detaches as NH3. Nevertheless, Phe, as the representative of aromatic amino acids, has the lowest NH3/HCN ratio. Additionally, it is interesting to find some phenomena in common for the aromatic amino acids and aliphatic amino acids. The introduction of steam is proven to enhance the hydrogenation of char-N, the thermal cracking of tar-N, and the hydrolysis of HCN into NH3, thus promoting the NH3 selectivity. The NH3-N yield increases initially and then suppresses at 700–900 °C, which is impacted by the extent of NH3 decomposition reaction. High steam content can contribute to the enhanced availability of H radicals, consequently resulting in significant release of NH3.

Solid oxide cells with cermet of silver and gadolinium-doped-ceria symmetrical electrodes for high-performance power generation and water electrolysis

A cermet of silver and gadolinium-doped-ceria (Ag-GDC) is investigated as novel symmetrical electrode material for (ZrO2)0.92(Y2O3)0.08 (YSZ) electrolyte-supported solid oxide cells (SOCs) operated in fuel cell (SOFC) and electrolysis (SOEC) modes. The electrochemical performances are evaluated by measuring the current density-voltage characteristics and impedance spectra of the SOCs. The activity of hydrogen and air electrodes is investigated by recording overpotential versus current density in symmetrical electrode cells, respectively in hydrogen and air, using a three-electrode method. Conventional hydrogen electrode, Ni-YSZ, and oxygen electrode, LSCF (La0.6Sr0.4Co0.2Fe0.8O3-δ)-GDC, are tested as comparison. The results show that, as an oxygen electrode, Ag-GDC is more active than LSCF-GDC in catalyzing both oxygen reduction reaction (ORR) in an SOFC and oxygen evolution reaction (OER) in an SOEC. As a hydrogen electrode, Ag-GDC is more active than Ni-YSZ in catalyzing hydrogen oxidation reaction (HOR) in an SOFC and hydrogen evolution reaction (HER) in an SOEC, especially in high steam concentration. An SOC with symmetrical Ag-GDC electrodes operated in a fuel cell mode, with 3% H2O humidified H2 as the fuel, displays a peak power density of 395 mWcm−2 at 800 °C. Its polarization resistance at open circuit voltage is 0.21 Ω cm2. Ag-GDC electrode can be operated even at pure steam. An SOEC operated for electrolyzing 100% H2O, the current density reaches 720 mA cm−2 under 1.3 V at 800 °C.

Deficiency of hydrogen production in commercialized planar Ni-YSZ/YSZ/LSM-YSZ steam electrolysis cells

Deficient, or non-linear hydrogen production is for the first time experimentally observed in large-scale planar Ni-YSZ/YSZ/LSM-YSZ steam electrolysis cells. The apparent coinciding of the concentration polarization and Faraday efficiency decrease at certain current density (−0.5Acm−2 or -0.6Acm−2 for selected steam content) indicates that steam starvation appears to affect the hydrogen production's linearity, which in essence the Ni/NiO redox process is believed to play a role in such normal SOEC operations. The SOEC survives 10h extreme polarization through electric conduction and oxygen vacancy transportation. Rational SOEC working mode is recommended accordingly. The present work is complementary for the general application of the Faraday's Law to estimate hydrogen production, and to further evaluate the SOEC's overall characteristics.

Preparation of polydopamine-derived carbon-based nano-Fe catalysts and its catalytic conversion of toluene for hydrogen production

Carbon-based metal catalysts have excellent catalytic performance due to their porous structure and high dispersion of metal particles. In this paper, polydopamine (PDA) microspheres as carbon supports and Fe as the metal phase are used to synthesize carbon-based nano-Fe catalysts for catalytic cracking of toluene. The PDA derived carbon-based metal catalysts has more regular spherical shape when compared with biomass derived catalyst. The effect of activation steam concentration and Fe load on the characteristics of catalyst have been studied. As the concentration of activated steam increases from 7.5% to 15%, the specific surface area of the carbon support increases significantly, and the number of micropores also increases. When the Fe impregnation concentration is less than 5%, the dispersion of the metal particles on the surface of the carbon support is very good, and when the Fe impregnation concentration is greater than 5%, the metal particles on the surface of the carbon support begin to agglomerate. The introduction of this catalyst can significantly increase the removal efficiency of toluene and the hydrogen content of tail gas. The carbon-based metal catalysts before and after the toluene catalytic cracking experiments are characterized and found that the microporous structure played an important role in the removal of toluene, and the C─O functional groups and ─OH groups on the catalyst surface also played an important role in the catalytic process. The addition of Fe species can increase the specific surface area and promote the formation of surface functional groups, and can also strengthen the π-π interaction and electrostatic interaction on the catalyst surface. The lattice oxygen introduced by iron oxide can provide oxygen source for the oxidation reaction of toluene.

Reduced concentration polarization and enhanced steam throughput conversion with a solid oxide electrolysis cell supported on an electrode with optimized pore structure

Conversion of steam to hydrogen in solid oxide electrolysis cells (SOECs) is largely limited by concentration polarization occurring in the supporting cathodes. The present study was thus aimed at reducing the concentration polarization and increasing the steam conversion by optimizing the pore structure of the cathodes. Button cells supported on cathodes with straight pore structure showed much improved performance than those with tortuous pore structure especially under steam-lean conditions (1.19 vs. 0.69 A•cm−2 at 1.3 V, 750 °C and 10% vol. % H2O). Impedance spectroscopy analysis indicated that the straight pore structure in the cathodes allowed for facile transport of steam, thus effectively mitigating the concentration polarization. The relation between the electrolysis current density and steam concentration determined from the button cells was used to simulate the electrolysis performance of single cells. The simulation predicts that single cells with the straight pore structure in the cathodes can achieve high steam throughput conversion even at high steam feeding rate.

Prediction Method for Condensation Heat Transfer in the Presence of Noncondensable Gas for Computational Fluid Dynamics Applications

Abstract The objective of this study was to present a prediction method for condensation heat transfer in the presence of noncondensable gas (air or nitrogen) for computational fluid dynamics (CFD) analyses, where physical quantities in the computational cells in contact with the structural wall are generally used. First, using existing temperature distributions T(y) in the turbulent boundary layer along a flat plate as functions of the distance y from the condensation surface, we evaluated the distribution of condensation heat flux qc,pre(y) from the gradient of steam concentration, we derived a modification factor η(y+) as a function of the dimensionless distance y+ to obtain a good agreement with qc,cal calculated by the qc correlation defined by using the bulk quantities; and we obtained qc,mod(y)/qc,cal = 0.90–1.10 for the region of y+ > 17. Second, we modified the local Sherwood number Sh(x) for flat plates for the boundary layer thickness δ and obtained the function Sh(δ). An existing qc correlation for flat plates as a function of Sh(δ) was applied to predict the distribution of the local value qc,pre(y), and qc,pre(y)/qc,cal = 0.95–1.15 in the best case was obtained for the region of y+ > 30. Finally, a correlation of the local Sherwood number Sh(y) was derived from the temperature distributions T(y) as a function of the local Reynolds number Re(y).

Morphological and heat transfer characteristics of biomass briquette during steam gasification process

The morphological evolution and heat transfer characteristics of biomass briquette greatly affect the directional regulation of target products during steam gasification process. In this work, a visual gasifier with an on-line temperature monitoring system was developed to investigate the coupling relationship between the morphological change and temperature distribution of biomass briquette. The gasification behaviors of biomass briquette at different temperatures and steam concentrations were comprehensively examined and compared. The shrinkage rate and heating rate of biomass briquette both reached the maximum at 1–2 min. The morphological evolution of biomass briquette in the heating process was shrinking particle mode, then changed to the shrinking core mode when the biomass temperature kept relatively stable. The high-quality syngas with a high H2/CO ratio of 3.07 at 50 vol% steam concentration and 700 °C was obtained, which were idealized to synthesize other fuels/chemicals.

Numerical analysis of transient coupled heat and moisture transfer in textile drying with porous relative impact jet

Convective drying of textiles is a multi-physical problem coupled with fluid flow, heat, and mass transfer, and is directly affected by the form of air supply. In this study, a coupled heat and mass transfer model for convective drying of textiles was established by focusing on the effects of a porous relative impinging jet on the coupled heat and mass transfer of textiles under different influencing factors. The results show that temperature and wind velocity, as the two most important influencing parameters, change the variation of steam concentration and convective heat transfer coefficient, respectively, thus affecting the drying process. Reducing the relative humidity of the air in the oven can accelerate the drying process. The accuracy of the proposed model was validated against the experimental results, and the error was within 10%. The optimal operating conditions (v = 10 m/s, T = 180 ℃, RH = 10%) were determined via numerical simulation. The air supply mode of the orifice impinging jet accelerated the drying rate and simultaneously improved the uniformity of the change in textile moisture. The model enhances the understanding of the impinging jet drying mechanism for textiles and provides theoretical guidance for fabric drying equipment such as heat-setting machines.

Numerical analysis of a pre-chamber vortex burner with a steam blast atomizer

The combustion of diesel fuel in a pre-chamber vortex burner with a steam blast atomizer has been studied numerically. The well-proven k-w SST (URANS) model was chosen for calculations. Combustion was simulated using the Eddy Dissipation Concept (EDC) model, taking into account detailed chemical mechanisms in turbulent reacting flows. The results of testing the selected mathematical model showed good agreement of calculations with the known experimental data, a high agreement of the results was achieved: temperature, CO, NOx, O2, and CO2. The influence of steam and fuel flow rates on the flow structure and physicochemical processes in the burner and at the nozzle outlet has been studied. The structure of the flow inside the burner was shown. A high-velocity jet of steam ejects fuel, oxidizer flow and hot combustion products, forming a large zone of circulation and intense mixing. The influence of burner operating regimes on fuel underburning and environmental performance has been investigated. It was found that in the selected range an increase in the relative steam flow rate leads to almost complete combustion of fuel inside the burner. In the combustion chamber with a natural air supply, the excess air ratio was (0.96–1.23). For the considered fuel flow rate of (0.8–1.2 kg/h), the concentration of toxic emissions meets the environmental standard EN:267 – CO < 40 ppm, NOx < 50 ppm. The minimum emissions of CO = 5 ppm and NOx = 27 ppm are achieved at mass steam concentration of 44–50%.

New ways to generate electricity using steam evaporative cooling systems for high-temperature iron and steel plants

Currently, the thermal energy of steam generated by evaporative cooling systems of high-temperature ferrous metallurgy units is used practically only for space heating and hot water supply. This ineffective use occurs because evaporative cooling systems generate steam with a steam content of 0.9 at best and often just a steam-water mixture. As a result, it cannot be used for the operation of steam turbines, and in the case of a steam-water mixture, for the operation of classic steam engines and conventional steampiston engines, which are high-speed single-expansion steam engines. This article will discuss the possibility of using a steam-piston engine to generate electricity from steam generated by evaporative cooling systems. In contrast to the classic reciprocating steam engines, the steam-piston engines have a relatively high rotational speed. As a result, they are smaller and can be connected directly to modern power generators with a 1500 rpm speed. Furthermore, such engines can be manufactured by converting serial internal combustion engines, which significantly reduces their cost and provides a short payback period for such equipment. The first option is to use steam-piston engines to operate on steam with a steam content of 0.9; in this operating mode, steam-piston engines have relatively high efficiency for steam parameters generated by evaporative cooling systems. However, this option requires the use of a steam separator. The second option involves using unique steam-piston engines that can operate on a steam-water mixture and even on overheated water. These engines can use a steam-water mixture directly from evaporative cooling systems without separation, but in this case, efficiency is considerably lower.

High temperature oxidation of AISI 441 in simulated solid oxide fuel cell anode side conditions

This study investigates the corrosion of AISI 441 in simulated anode conditions of solid oxide fuel cells (SOFCs). Several parameters such as temperature, humidity, surface condition, pre-oxidation temperature and environment, were investigated. Samples pre-oxidized at 800 ºC were protective at 550–900 ºC, while as-received samples showed protective behavior only at 900 ºC. Additional exposures performed at 600 ºC revealed the negative effect of increasing steam concentration, the beneficial effect of grinding, while pre-oxidation at 600 ºC did not improve the protectiveness. The role and the interplay of the aforementioned factors are discussed.

Surface restructuring of a perovskite-type air electrode for reversible protonic ceramic electrochemical cells

Reversible protonic ceramic electrochemical cells (R-PCECs) are ideally suited for efficient energy storage and conversion; however, one of the limiting factors to high performance is the poor stability and insufficient electrocatalytic activity for oxygen reduction and evolution of the air electrode exposed to the high concentration of steam. Here we report our findings in enhancing the electrochemical activity and durability of a perovskite-type air electrode, Ba0.9Co0.7Fe0.2Nb0.1O3-δ (BCFN), via a water-promoted surface restructuring process. Under properly-controlled operating conditions, the BCFN electrode is naturally restructured to an Nb-rich BCFN electrode covered with Nb-deficient BCFN nanoparticles. When used as the air electrode for a fuel-electrode-supported R-PCEC, good performances are demonstrated at 650 °C, achieving a peak power density of 1.70 W cm−2 in the fuel cell mode and a current density of 2.8 A cm−2 at 1.3 V in the electrolysis mode while maintaining reasonable Faradaic efficiencies and promising durability.

STEM resource compilations for West Virginia.

First2 Network, NASA Educator Resource Center (ERC), WV Department of Education (WVDE), and WV Alliance for STEM and the Arts offer compilations of WV STEM resources that serve undergraduate and K12 students, parents, educators, industry, and other STEM stakeholders throughout WV. Learn how to use and submit events to these resource compilations, and how they are connected. First2 Network’s WV STEM Hub is a searchable online inventory of West Virginia STEM-related assets, resources and opportunities. The NASA ERC aims to spotlight NASA internships for high school and undergraduate students through the Careers in the Corridor event, and to add industry partners to the WV STEM Hub and WVDE STEM Ecosystem. The main objective is to help develop STEM career pipelines by providing early awareness career explorations for WV students. STEAM Trek is a free web-based, interactive game platform for WV students to explore STEAM content and resources available from organizations, institutions, and individuals from WV and beyond. A new corridor in the game space is planned, to serve as a virtual Careers in the Corridor event continuously available to the public.

Experimental study of the solar-driven steam gasification of coal in an improved updraft combined drop-tube and fixed-bed reactor

Solar-driven steam gasification of coal particles promises a new approach for efficiently storing concentrated solar power (CSP) in producer syngas and achieving solid fuels energetic upgrade. A 1.5-kWth improved updraft solar reactor combined with drop-tube and fixed-bed for the steam gasification of coal was designed, fabricated, and experimentally studied under a 7-kWe high-flux solar simulator (HFSS). The gasifier retains the advantages of the efficient radiative heat transfer, long particle residence time and excellent particle size adaptation to the conventional combined drop-tube and fixed-bed reactors (CDFR) while, however, improving pyrolysis conditions by changing the moving direction of the steam and feedstock to use the high-temperature producer gas to preheat coal particles. The aim of this work was to achieve a proof of concept for the newly designed solar gasifier applied to coal gasification. Additionally, a comprehensive parametric study considering different H2O/coal molar ratios (0.8–2.2), coal feeding rates (1.0–1.5 g/min), carrier gas flow-rates (2.5–3.5 Nl/min), temperature (1050 °C and 1150 °C) and heights of reticulate porous ceramic (3 cm and 6 cm) was conducted for optimizing the syngas composition and evaluating the gasification performance. The experimental data indicated the syngas yield increased obviously from 57.92% to 64.63% with the increasing temperature, while the increasing steam content favored H2, CO2 and CH4 and reduced CO mole fraction. The increasing heights of the reticulate porous ceramic (RPC) extended the particle residence time, resulting in the carbon conversion rate increasing over 8%. Maximum amounts of produced syngas over 100 mmol/min and carbon conversion rates over 70% were achieved. The coal energy content was solar-upgraded by a factor of 1.17 at 1150 °C. Compared with the conventional CDFR, the carbon conversion rate was promoted from 51.66% to 64.63% with the increasing pyrolysis temperature (up to 400 °C).

Transformation and fate of sulphur during steam gasification of a spent tyre pyrolysis char

The transformation of sulphur (S) during steam gasification of a spent tyre pyrolysis char (STPC) was investigated by tracing the evolution of S species and their mass fractions through X-ray photoelectron spectroscopy analysis. The raw pyrolysis char and demineralised char samples were respectively reacted with steam in a vertical fixed bed reactor over a range of temperature (850, 950, 1050 °C), steam concentration (33.3, 50.0, 66.7 vol% steam in N2) and gasification time (0.5, 1, 2, 3, 4 h). The mass fraction of S in the partially gasified char increased with increasing time at 850 °C and 950 °C, but decreased at 1050 °C. However, the net amount of S retained in the gasified char relative to that in the raw STPC decreased with increasing mass loss ratio, implying that S loss was faster than carbon consumption. The dominant S species in the pyrolysis char were aliphatic sulphide and ZnS. After steam gasification, more than 80% S species in the gasified chars were in the form of organic S. The proportion of organic S increased while that of inorganic S decreased with increasing gasification time and temperature, regardless of steam concentration. Thiophene, aliphatic sulphide, sulphone and sulphoxide became the main organic S species while ZnS and sulphate were the dominant inorganic S species. Aliphatic sulphide, sulphone and sulphoxide were converted to more thermally stable thiophene. Sx released from ZnS or COS produced from CaSO4 reacted with the carbon matrix to form sulphone and sulphoxide in the gasified char.

Theoretical Analysis of Critical Conditions for Crack Formation and Propagation, and Optimal Operation of SOECs

A theoretical analysis on crack formation and propagation was performed based on the coupling between the electrochemical process, classical elasticity, and fracture mechanics. The chemical potential of oxygen, thus oxygen partial pressure, at the oxygen electrode-electrolyte interface () was investigated as a function of transport properties, electrolyte thickness and operating conditions (e.g., steam concentration, constant current, and constant voltage). Our analysis shows that: a lower ionic area specific resistance (ASR), and a higher electronic ASR () of the oxygen electrode/electrolyte interface are in favor of suppressing crack formation. The thus local pO2, are sensitive towards the operating parameters under galvanostatic or potentiostatic electrolysis. Constant current density electrolysis provides better robustness, especially at a high current density with a high steam content. While constant voltage electrolysis leads to greater variations of Constant current electrolysis, however, is not suitable for an unstable oxygen electrode because can reach a very high value with a gradually increased A crack may only occur under certain conditions when

New ecology safe waste-to-energy technology of liquid fuel combustion with superheated steam

The huge amounts of accumulated unclaimed liquid hydrocarbon waste (waste from oil production and oil refining, etc.) determine the prospects for their involvement in energy production. The Waste-to-Energy technology improves economic efficiency through low energy costs. Efficient use of waste for energy production requires the creation of new technologies with high energy efficiency and low emissions. The paper proposes and substantiates a promising new environmentally friendly Waste-to-Energy method of burning liquid fuel with injection of superheated steam (SIM) to the combustion zone. The authors have developed a new burner to combust liquid waste when producing energy (protected by patents of the Russian Federation), in which the fuel is atomized by a jet of superheated steam. This approach provides efficient fuel dispersion, the ability to burn a wide range of waste, high fuel combustion efficiency, long service life due to the absence of fuel injectors, and reduction of toxic combustion products due to steam. The large-scale introduction of new burners based on the SIM combustion technology requires reliable scientific data and pilot test results. First of all, this is the influence of operating parameters (steam flow rate and temperature, fuel and air flow rates) on the combustion performance in the oil-steam burner being developed. The aim of the work is complex laboratory and experimental studies of the characteristics of fuel combustion in a new burner with a controlled excess air ratio. Forced air supply to the combustion chamber of a steam-oil burner is a novelty of the burner under study. Based on the results of laboratory studies, the optimal ratios of operating parameters were found (fuel, steam and air flow rates: 1:0.8:2.75), which provide the best thermal and environmental performance (NOx<35 ppm, CO < 25 ppm). A significant reduction in the content of nitrogen oxides in the flue gases up to 70% was achieved with a high completeness of fuel combustion due to the joint control of steam concentration and excess factor in the gas generation chamber. This claims the proposed burner as a low emission one. To confirm the achieved effect, in this work, for the first time, experimental tests of the burner were carried out under the operating conditions of a low-power boiler plant (10–40 kW). Successful tests prove the efficiency of using the developed burner for solving the problem of efficient and environmentally friendly combustion of fuel (including liquid combustible waste) for the production of thermal energy at small-scale energy facilities.

Numerical study on the effect of CO2 on the heat transfer characteristics of steam condensation outside a vertical tube

Under severe accident conditions of a pressurized water reactor nuclear power plant, the reactor core may melt, and the molten corium even reacts with concrete in the containment, producing a large amount of CO2 into the entire containment gas space. This may have an obvious impact on the heat transfer characteristics of steam condensation in the containment. However, there are few studies focused on this phenomenon. In this paper, a commercial CFD software, STAR-CCM+, is used to study the effect of CO2 on steam condensation heat transfer. The calculations are based on 0.4 MPa gas pressure, 40 K wall sub-cooling, 0.66 or 0.2 steam mole fraction, and the CO2 mole fraction varies from 0 to 0.34 or 0.8. The results show that the CO2 demonstrates different influence laws at high and low steam concentrations, respectively. When the steam mole fraction is 0.66, as the proportion of CO2 in the non-condensable gas increases, the condensation heat transfer coefficient (HTC) will increase, and the enhancement can reach 30%. When the steam mole fraction is 0.2, the condensation HTC will first decrease and then increase, as the proportion of CO2 in the non-condensable gas increases. The effects of gas pressure and wall sub-cooling on the condensation HTC are also analyzed. The results show that the condensation HTC increases with the increase of the gas pressure and decreases with the increase of wall sub-cooling.