Exhaust Steam Research Articles

Study of a gas turbine unit energy efficiency

The method of the gas turbine unit and the waste heat boiler gas-air duct circuit modernization is considered. The operation scheme of a gas turbine unit and a waste heat boiler with the use of a catalytic afterburner has been shown. There is also a decrease in nitrogen and carbon oxides in the exhaust steam-and-gas mixture due to a deeper cleaning process of the exhaust steam and gas mixture, which leads to an increase in the service life of the waste heat boiler [1]. A more complete process of heat transfer to the coolant in the furnace section of the boiler is performed due to the cleaner steam and gas mixture in the waste heat boiler and due to a decrease in the boiler tubes growth formation by the combustion products. This makes it possible to reduce the cost of fuel consumption by gas burners of the waste heat boiler. Also, as a result of this process, it is possible to reduce fuel consumption for the needs of heating the feed water and the auxiliary needs of a power unit. This article proposes to use lattice devices in the afterburner, treated with active substances by the ion implantation method, as one of the most promising ways of modifying lattice surfaces [2 – 6]. These processes occurring when the steam-and-gas mixture passes through the afterburner, allow increasing the cycle efficiency factor and limit of maximum allowable concentrations (MAC) emissions for various options for the exhaust steam-and-gas mixture utilization of a gas turbine unit (GTU) and heat supply to the waste heat boiler.

Study and Redesign of Aircooler System in a 16 MW Steam Turbine Surface Condenser at Neka Power Plant

According to the study of basic Rankin thermal cycle, the steam exhaust pressure of a typical steam turbine toward the condenser, plays a great role in the efficiency and the net output power of the steam turbine, so most surface condensers that are working in thermal power plants are kept at vacuum condition so that the maximum power of thermal cycle can be achieved. The vacuum pressure at condenser leads to the entering of air and Non-condensable gases from turbine gland seals to condenser so that the special air ejection equipment is being used to take apart air from steam and vent it to out of condenser. In this study, a special steam and air separator mechanism in an evacuating system called “Aircooler” at a 16 MW steam turbine condenser is being studied and the Fluent CFD software is utilized to analyze the behavior of steam plus air in a typical aircooler system of 16 MW steam turbine condenser of Neka power plant to find a way to reduce the risk of cooling tube rupture in aircooler ducts. The critical condition which tube rupture happens is determined and it is demonstrated that in hot seasons of year, by increasing the seawater cooling temperature and increasing in turbine steam exhaust pressure and temperature, the risk of tube rupture due to more mixture velocity at the first row of aircooler cooling tubes increases and also the effect of tube plugged condition on the performance of aircooler shows that the risk of other tubes rupture will increase and thus the efficiency of aircooler decreases due to more aircooler exhaust temperature. Finally, two modified plans at aircooler system design will be studied and simulated via Fluent CFD software which leads to reduce the risk of tube rupture. The results show that by modification of aircooler ducts and holes, the mixture air and steam flow velocity to first aircooler cooling tube row decreases significantly and causes the risk of tube rupture to decrease remarkably and also the exhaust temperature of aircooler decreases and causes the higher ejector performance.

Influence of replacement of steam power plant on combined cycle gas equipment on the sanitary protection zone by noise factor

Improving the safety of energy equipment of thermal power plants (TPPs) is an important task. The safety of power equipment is affected by physical influences, the most important of which is noise. Noise is one of the factors determining the size of the sanitary protection zone of thermal power plants. Article analyses the influence of TPP equipment structure on the size of sanitary protection zone (SPZ) by noise factor when replacing the equipment of traditional steam power plants with the equipment of steam and gas plants. Combined cycle gas plants (CCGT) are the most innovative technology in heat and power industry. Currently, most of exhausted steam turbine units (STU) replaced by CCGT. CCGTs are more economical and at the same time have better environmental performance, which consists in both less emission of pollutants and less noise exposure. STU supplied in standard configuration, as their efficiency slightly depends on external conditions. On contrary, the efficiency of CCGT significantly depends on climatic conditions. This dependence necessitates the implementation of individual projects, which allows at design stage of CCGT equipment to provide measures to reduce noise. Main CCGT’s noise sources are air inlet and gas outlet. At design stage, provide reducing sound pressure levels to regulatory values on border of SPZ. Data of calculations showing that increasing of STU power leads to an increase the size of the SPZ. Comparison with the results of calculations on semiempirical model and using computer of SPZ sizes at different type and structure of STU is given. Transition to supercritical steam parameters causes a jump in noise levels. Considered stepwise withdrawal of equipment and its replacement by CCGT. Described a decrease in noise levels at SPZ border. This allows performing equipment modernization in cities in conditions of developed residential building also with increase of plant capacity. Influence of climatic conditions on width of sanitary protection zones described. Shown that during the year boundaries of SPZ change at the same structure of equipment. The most correct is to specify interval in which boundaries of SPZ are located. These results allow selecting noise reduction measures more accurate.

Theoretical Design and Analysis of the Waste Heat Recovery System of Turbine Exhaust Steam Using an Absorption Heat Pump for Heating Supply

In northern China, many thermal power plants use absorption heat pump to recover low-grade heat from turbine exhaust steam due to the irreplaceable advantages of the absorption heat pump in waste heat recovery. In the process of designing a waste heat recovery system, few researchers have considered the relationship between the design power of the heat pump and the actual heating load of the heating network. Based on the heating load characteristics, this paper puts forward a design idea which uses an absorption heat pump to recover waste heat from a steam turbine exhaust for heating supply. The operation mode of the system for different design powers of the heat pump was stated. An economic analysis model of the waste heat recovery system was proposed, and the optimal design power of the heat pump could be obtained. For a specific unit, the corresponding waste heat recovery system was designed, and various factors affecting the economy of the system were discussed and analyzed in detail.

Dual-radiation-chamber coordinated overall energy efficiency scheduling solution for ethylene cracking process regarding multi-parameter setting and multi-flow allocation

This work proposes a novel energy efficiency scheduling solution for cracking process, which achieves energy efficiency improvement comprehensively and scientifically. The proposed solution reflects several significant features of process operation, for example, the impact of COT, COP, and dilution ratio on product output and energy utilization, the influence of SHS recycle energy and exhaust gas energy loss on fuel and DS consumption. Also, DRC independent parameter setting and asynchronous batch processing have also been taken into account with scheduling of cracking furnace groups. Ethylene cracking process is the core production process in ethylene industry, and is paid more attention to reduce high energy consumption. Because of the interdependent relationships between multi-flow allocation and multi-parameter setting in cracking process, it is difficult to find the overall energy efficiency scheduling for the purpose of saving energy. The traditional scheduling solutions with optimal economic benefit are not applicable for energy efficiency scheduling issue due to the neglecting of recycle and lost energy, as well as critical operation parameters as coil outlet pressure (COP) and dilution ratio. In addition, the scheduling solutions mostly regard each cracking furnace as an elementary unit, regardless of the coordinated operation of internal dual radiation chambers (DRC). Therefore, to improve energy utilization and production operation, a novel energy efficiency scheduling solution for ethylene cracking process is proposed in this paper. Specifically, steam heat recycle and exhaust heat loss are considered in cracking process based on 6 types of extreme learning machine (ELM) based cracking models incorporating DRC operation and three operation parameters as coil outlet temperature (COT), COP, and dilution ratio according to semi-mechanism analysis. Then to provide long-term decision-making basis for energy efficiency scheduling, overall energy efficiency indexes, including overall output per unit net energy input (OONE), output-input ratio per unit net energy input (ORNE), exhaust gas heat loss ratio (EGHL), are designed based on input–output analysis in terms of material and energy flows. Finally, a multi-objective evolutionary algorithm based on decomposition (MOEA/D) is employed to solve the formulated multi-objective mixed-integer nonlinear programming (MOMINLP) model. The validities of the proposed scheduling solution are illustrated through a case study. The scheduling results demonstrate that an optimal balance between multi-flow allocation, multi-parameter setting, and DRC coordinated operation is reached, which achieves 3.37% and 2.63% decreases in net energy input for same product output and conversion ratio, as well as the 1.56% decrease in energy loss ratio.

Superheated steam drying and its applicability for various types of the dryer: The state of art

Superheated steam is a vital drying media due to inherently passive, nonpoisonous, no fire risk, antioxidant, and compatible with food products with superb thermophysical properties than hot air. Moreover, it will improve energy efficiency by energy-saving due to reusing the energy from exhausted steam, mainly by recirculation, and the use of partial exhaust of excess steam for other operations reduces the additional energy requirement. Additionally, the specific heat at constant pressure for superheated steam is nearly double that of the hot air, reducing the quantity required for drying. In general, superheated steam as a drying medium instead of hot air has significant potential. In this study, past, present, and prospects of the superheated steam drying (SSD) are critically analyzed and are presented systematically, such as classification, working, and recent developments. This study also focused on various areas such as analytical modeling, experimental work, and pilot-test of SSD with covering energy recovery and energy efficiency. Out of different drying systems, Fluidized bed dryers, Vacuum dryers, Rotary dryers, Flash dryers, Impingement dryers, and Spray dryers applicable for SSD are discussed in details as the current stage of development and probable potential. The SSD is having bright future for diverse applications including vegetable drying and fruit processing, chemical process industries, wood drying, chemicals, dyestuff and pigments recovery, effluent drying, etc.

Thermodynamic, operational, and techno-economic analysis of the cascade heating system with a double-unit

High back-pressure technology is an efficient way to recover waste heat and improve the energy utilization efficiency and heating capacity of cogeneration systems. In this study, a coal-fired cogeneration system with a double-unit (2 × 300 MW) was selected as the reference system and modeled in the EBSILON professional system. Then, a detailed comparative analysis of cogeneration systems with double-units was conducted from the perspective of thermodynamic, operational, and techno-economic analyses. The results show that with the high back pressure technology, the gross thermal and generation efficiencies of the novel system increased by 8.82% and 14.28%, respectively, while the standard coal consumption rate for generation was reduced by 43.47 g/kWh. Besides, the average energy quality coefficient of the novel system was reduced by 0.12. The temperatures of the exhaust steam, supplied and returned water changed the operational characteristics, including the maximum heating capacity and feasible operational region. Moreover, with the decrease in the maximum temperature rise ratio in the heating condenser, the feasible operational region of the novel system was reduced. The techno-economic analysis shows that under the given conditions, the net annual revenue of the novel system is 3.55 × 106 CNY/year, and the discounted payback period of the novel system is 10.55 years.

Particle Image Velocimetry (PIV) experiment of the buoyant flow field of a thermal chimney model designed for geothermal power plants

ABSTRACT To enhance the air-cooling process in geothermal power plants for economical utilization of the exhaust steam from expansion, a natural-draft thermal chimney design was proposed and studied here in this paper. In view of the necessity of accurate velocity field measurements which would provide further insight into the physics behind the evolving plumes above heated horizontal cylinders, Particle Image Velocimetry (PIV) was employed to experimentally investigate the buoyant flow in the thermal chimney system. Two configurations have been tested to understand the flow induced by the horizontally heated cylinders inside the thermal chimney. Firstly, flow field above a single row of cylinders was tested while they were isothermally heated to simulate of an air-cooled condenser. After that, a second row of cylindrical heaters (air-heater) was added above the first row to enhance the buoyant flow, aiming at enhancing the air side flow of the air-cooled condenser. Flow characteristics and velocity enhancement were studied for both configurations. The results show that significant flow unsteadiness occur near the cylindrical heaters because of the non-steady crossing flows between adjacent cylinders, and the unsteadiness attenuates in the downstream. The effects of cylinder row distance, surface temperature as well as downstream distance on the flow field were then analyzed. Flow velocity is increased by the air-heater as the buoyancy force is enhanced, proving the idea of flow enhancement of the thermal chimney configuration. It is also observed that the velocity fluctuation, turbulent kinetic energy and vorticity change significantly after adding the second row of heaters. The present study provides further insight into natural convection flow theory of heated cylinders for a Rayleigh number range of 1.3E4 to 2.2E4, which is fundamental for the flow enhancement designing of the proposed natural-convection-driven cooling system.

Analysis On Optimization Operation Of Cold End Of 600MW Wet Cooling Sub-critical Air Cooling Unit

Due to its remarkable water-saving characteristics, direct air cooling device has been widely used in carbon rich and water deficient areas in China. However, in the high temperature period in summer, the exhaust pressure of air cooling unit will rise greatly, the exhaust steam temperature will be high and the condensate temperature will be high. In this paper, Daihai Power Plant Phase I unit transformation as the research object, the cold end optimization of air cooling unit is analyzed, in order to improve the unit operation economy.

The blast air preheating of an power boiler CHP ZIGM

To improve the efficiency of the steam-turbine thermal power plant by reducing heat loss in a cold source by regenerating part of the heat of condensation of steam exhaust in the turbine, it is proposed to preheat the boiler blast air in a heat exchanger with circulating water heated in a steam turbine condenser. Saving of heat energy in monetary terms due to the use of part of the heat of condensation of steam in the turbine during preheating of the blast air of the ener-gy boiler BKZ-420-140 NGM of the Samara Thermal Power Plant to 20 °C is 13.244 mln rub/year. The design of an air-preheating unit for preheating the blast air of the power boiler BKZ-420-140 NGM has been developed, in which the heating coolant is circulating water heated in a steam turbine condenser. Variant calculations were carried out, as a result of which the main thermal performance parameters of the installation were determined at different boiler loads and outdoor temperatures.

A novel cascade heating system for waste heat recovery in the combined heat and power plant integrating with the steam jet pump

Waste heat utilization is an essential approach for improving the energy utilization efficiency of the combined heat and power (CHP) plant and a significant low-carbon way to achieve clean urban heating. To recover the excess exhaust steam heat of the CHP plant with the high back-pressure turbine (CHP-HBP), this paper proposed a novel heating system integrated with the steam jet pump (SJP). The EBSILON software was applied for modeling the proposed thermal system and analyzing the thermal performance of the CHP-HBP heating system under different operating conditions. On this basis, the coupled component-system design solution was proposed by combining the 1-D mathematical design model of the SJP with the heating system performance. Compared with the conventional system, under the design condition, the exhaust steam recovery rate and the heating capacity of the novel system had a significant increment of 8.66% and 31.8 MW with the same power output. Meanwhile, the total exergy loss and standard coal consumption rate for electricity generation of the novel system reduced by 5.74 MW and 6.77 g/kWh, respectively, with about 2.32% improvement in electricity generation efficiency. The critical parametric influence analysis on the overall performance showed that the novel system has better adaptability with some fluctuations of turbine back-pressure, supply/return water temperatures, and heating load. Under off-designed conditions, the recovery rate of the exhaust steam of the novel system was 5–20% higher than that of the conventional system, and the coal consumption rate and electricity generation efficiency both performed better. In all, the proposed system provided a promising method for the effective utilization of waste heat in the field of clean heating and the energy system optimization and integration for the coal-fired CHP plants.

Effect of water spray in exhaust passage of steam turbine on flow field of the last stage during windage

Under the windage condition, the steam in the last stage of steam turbine absorbs energy from rotor blade, which leads to overtemperature of the exhaust steam. Water spray is an effective way to lower the temperature in exhaust passage. The Euler-Lagrange particle tracking method is used to study the heat and mass transfer of the water spray in exhaust passage. The quantity of water spray under different conditions is predicted and the effect of water spray on the last stage flow field is analyzed. The results show that there is a small temperature difference between steam and liquid in the exhaust passage and a minimum evaporation of droplets for high steam velocity. The water spray quantity has a negative correlation with the inlet steam mass flow rate under different conditions and the ratio of water spray quantity to the inlet mass flow rate (water/steam ratio) has a quadratic relationship with the operating conditions. From 20%THA (Turbine Heat Acceptance) to 7%THA, the ratio of steam evaporated by water to mixture-vapor (H2O/mixture-vapor ratio) increases from 0.05% to 0.95%, and the water/steam ratio increases from 22% to 300%. The water spray has little effect on the rotor-stator clearance vortex and the separation vortex, but the height and velocity of the back flow vortex are increased. Meanwhile, the pressure of the last stage and the pressure ratio of the rotor blade increase, which result in the dissipating shaft power of the rotor blade reduces. Water spray has an effect on the flow field of the last stage, which is of great significance to correctly predict the windage conditions and study the dynamic characteristics of the rotor blade.

Energy and exergy analysis of a new cogeneration system based on an organic Rankine cycle and absorption heat pump in the coal-fired power plant

A new cogeneration system based on ORC (organic Rankine cycle) and AHP (absorption heat pump) is presented to achieve the dual effects of improving power output and heating capacity in a coal-fired power plant. The heat source for heating is firstly led into the ORC to generate power, and then is led into the AHP as the driving heat source to recycle waste heat from exhausted steam of the ST (steam turbine) when the energy grade is reduced to a level that matches with the heating energy grade. On the basis of the thermodynamic first and second law, focusing on 135 MW coal-fired power plant, the energy and exergy analyses of traditional cogeneration system and new cogeneration system with ORC and AHP have been completed. Compared to the traditional cogeneration system, the power output and heating capacity are respectively increased by 1.47 MW and 32,106.64 kW when the flow rate of heating extraction steam is 40 kg/s. The integral thermal and exergy efficiencies are improved by 9.38% and 1.71%. Moreover, the coal consumption decrement for power generation and heat-supplying both augments with increasing heating extraction flow rate and decreasing load. The new presented scheme can not only reduce the irreversible loss of the cogeneration system but also save coal consumption.

Dynamic modeling of thermal-supply system for two-by-one combined-cycle gas and steam turbine unit

The two-by-one (2 × 1) combined-cycle gas turbine (CCGT) unit with condensation-extraction-backpressure (C-E-B) steam turbine has become the major means of peak regulation in China because of its flexible operating mode. However, mode switching of the unit often causes drastic fluctuation of the water level of heating network thermos-exchanger and jeopardizes unit safety. In order to study the suppression mechanism of the water level fluctuation in the transient mode of switching, first a dynamic mathematical model of the thermal-supply system of the C-E-B steam turbine is developed based on a mixed approach of theory and identification. Then field data is used to verify model accuracy. Through step response analysis on the heat-supply system, the relationship between the extraction flow to the thermos-exchanger and its water level is identified along with the major influential factors. On the heat-demand system, the circulating water flow through heating network influences the heat transfer of thermos-exchanger, the exhaust steam pressure of turbine, the extraction flow and the water level in sequel. Combining the factors from the two systems arrives at the conclusion that the circulating water flow stabilizes the water level during mode switching process and provides theoretical basis for water-level controller design.

Towards zero water consumption in solar tower power plants

Important efforts are dedicated to reduce water use in the power generation sector. In this paper the use of a dry Heller cooling system is proposed to diminish the water consumption of a concentrated solar tower power plant. The Heller system is an indirect cooling system where the exhaust steam from the turbine is condensed in a direct contact heat exchanger. Part of the condensate and cooling water are pumped to the feed water heaters while the rest is pumped to the dry cooling tower. In this particular case a natural draft dry cooling tower is employed.The detailed cycle of the power block and the cooling system have been modeled. The results indicate an increase of the energy production by almost 6% compared to a mechanically draft dry cooling system and a reduction of the annual energy production of less than 3.7% compared to a wet cooling system. Furthermore, it has been found that this cooling system is able to reduce almost 1.4·106m3 of water per year, which makes it an attractive choice especially in arid regions.A cost model has been presented to determine the equivalent water price that makes profitable the use a Heller system (Water price =1.96$/m3).

INFLUENCE OF THERMAL RESISTANCE OF AIR CONDENSER TUBES ON STEAM COOLING EFFICIENCY


 
 
 The research is carried out using a mathematical model of conditions and features of condensation processes with the influence of changes in internal and external thermal resistances of working bodies, which occur during contamination of outside and inside metal pipes of heat exchange surfaces of air condenser. capacitor. Particular attention is paid to the selection, detailing and determination of more than twenty basic parameters that characterize the operation of the direct cooling unit of the condensing unit for the summer, the conditions of heat transfer processes between the working bodies taking into account the finned outer surface of elliptical condenser tubes. The results of experiments on the mathematical model are analyzed and the influence of the incoming air velocity and ambient temperature on the output steam pressure in the condenser direct air cooling system within the change of internal and external thermal resistances in the range 0-0.001(m2·K)/W due to cooling tube contamination is determined. air condenser steam turbine installation. Conditions, character and features of influence of thermal resistance of pollution in cooling tubes on steam pressure at an exit from them are defined, the basic factors defining steam pressure at an exit, necessity of the organization of control of thermal resistance of pollution in a pipe during unit operation at variable operating conditions and expediency is substantiated. conducting test studies of operating modes while taking into account the influence of thermal resistance of external and internal pollution on the thermal efficiency of the cooling unit.
 
 
 
 Studies have shown that at a fixed value of the heat load of the exhaust steam, the pressure of the steam outlet increases with increasing ambient temperature and decreasing the speed of the incoming air.
 
 
 
 
 

A novel super high back pressure cascade heating scheme with multiple large-scale turbine units

The recovery of waste heat from power generation by the utilization of energy cascade for district heating has become an important method to improve the energy saving of combined heat and power (CHP) plants. In this paper, a novel super high back pressure (SHBP) cascade heating scheme is proposed to recover waste heat further and tap the energy saving potential of multi-unit combined heating system. On this basis, the regulation progress under full heating conditions is simulated. It’s concluded that the regulation progress can be divide into 4 stages, and the flow of extraction steam or the back pressure of turbines is adjusted to satisfy the varying heating demand. Furthermore, the detailed thermodynamic analysis of the novel cascade heating scheme is performed. The results indicate that, in the design condition, the heating process exergy efficiency of the SHBP scheme is improved by 10.4%, leading to an addition of 136.6 MW in generating power and a decline of 30.1% in the heating consumption rate. During the whole heating period, exhaust steam heat load ratio of the SHBP system reaches to 92.5%, which brings about the average heating consumption rate only 5.30 kg/GJ, and 72 thousand tons standard coal saved in total.

Research on a Coupled Total-Flow and Single-Flash (TF-SF) System for Power and Freshwater Generation from Geothermal Source

In response to the twin development challenges of energy shortage and water-scarcity in worldwide arid to semi-arid regions with geothermal resources, a new combined power and freshwater generation system is proposed for geothermal energy utilization. In this system, a total-flow turbine (TF) is employed to be coupled with the traditional single-flash (SF) system and thereafter the coupled TF-SF system is investigated in this work. In addition to power generation, the exhaust steam from turbines are recovered to produce freshwater through condensation. Based on the novel designed system, the production of both power and water are studied under variable wellhead conditions, including variable wellhead pressures, temperatures, mass flowrates, and vapor qualities. The temperature of the separating point at which the total-flow expansion ends and the steam expansion starts is studied for optimal system output. In addition, the efficiency effects of the total-flow turbine on performance of the combined system is also investigated. The power generation comparison shows good power potential of the proposed TF-SF combined system. An effective total-flow turbine with an average efficiency of 65% can lead to an optimal power capacity, exceeding the traditional single-flash (SF) system by 23.7%. Moreover, more than 1/3 of total wellhead discharge can be recovered as desalinated freshwater by the naturally equipped condensation process of the power plant, showing extra benefit from geothermal energy utilization.

Improving the thermal efficiency of a T-GDI engine using hydrogen from combined steam and partial oxidation exhaust gas reforming of gasoline under low-load stoichiometric conditions

Hydrogen (H2) addition is known to have features of increasing the laminar burning velocity (Di Sarli and Di Benedetto, 2007), the resistance of the flame to strain-induced extinction (Di Sarli and Di Benedetto, 2012, 2013), and also enlarging the operating window of stable combustion (Di Sarli, 2014). We experimentally investigated how to improve the thermal efficiency of a turbo gasoline direct injection (T-GDI) engine using H2 from combined steam and partial oxidation exhaust gas gasoline reforming under low-load stoichiometric conditions. During real driving, 4 and 6 bar brake mean effective pressure (BMEP) at 2,000 rpm are frequently used. Our experimental results show that reformed H2 improves the brake thermal efficiency (BTE) of T-GDI engines operating at 4 and 6 bar BMEP. Furthermore, the combustion speed (increasing heat release rate) and stability (reducing cyclic variation) were enhanced by reformed H2, making more heavy exhaust gas recirculation (EGR) operation. Combining steam and partial oxidation exhaust gas gasoline reforming with extra air injection to a reformer had a large effect on the fuel conversion efficiency of the reformer as the engine load decreased. Therefore, the BTE of the T-GDI engine with combined steam and partial oxidation reforming achieved further improvement over steam reforming only at 4 bar BMEP. Nitrogen oxide (NOX) emissions increased with reformed H2. However, on the basis of the improved combustion stability achieved using reformed H2, NOX emissions could be reduced further by using a higher EGR rate while enhancing the BTE.

Performance Study on Methanol Steam Reforming Rib Micro-Reactor with Waste Heat Recovery

Automobile exhaust heat recovery is considered to be an effective means to enhance fuel utilization. The catalytic production of hydrogen by methanol steam reforming is an attractive option for onboard mobile applications, due to its many advantages. However, the reformers of conventional packed bed type suffer from axial temperature gradients and cold spots resulting from severe limitations of mass and heat transfer. These disadvantages limit reformers to a low efficiency of catalyst utilization. A novel rib microreactor was designed for the hydrogen production from methanol steam reforming heated by automobile exhaust, and the effect of inlet exhaust and methanol steam on reactor performance was numerically analyzed in detail, with computational fluid dynamics. The results showed that the best operating parameters were the counter flow, water-to-alcohol (W/A) of 1.3, exhaust inlet velocity of 1.1 m/s, and exhaust inlet temperature of 773 K, when the inlet velocity and inlet temperature of the reactant were 0.1 m/s and 493 K, respectively. At this condition, a methanol conversion of 99.4% and thermal efficiency of 28% were achieved, together with a hydrogen content of 69.6%.