Stack Test Research Articles

Degradation prediction of proton exchange membrane fuel cell based on the multi-inputs Bi-directional long short-term memory

The remaining useful life (RUL) is one of the most crucial indicators for proton exchange membrane fuel cell (PEMFC). The existing data-driven prediction algorithms have the problem of low prediction accuracy with finite training data. This paper proposes a multi-input single-output Bi-directional long short-term memory (MISO-BiLSTM) to improve the prediction accuracy. First, a bi-exponential empirical model is developed to reduce the voltage data error caused by stack test start/stop. Second, a Pearson approach is employed to extract RUL-related indicators as input to MISO-BiLSTM to decrease prediction error. Finally, the BiLSTM prediction models are developed for each input separately to improve the prediction performance under limited data. The MISO-BiLSTM prediction method is experimentally validated using experimental data from PEMFC under static and dynamic operating conditions. The results demonstrate that the root mean square error (RMSE) of the MISO-BiLSTM prediction algorithm proposed in this paper are 0.00282 and 0.00386 under 300h train data. The proposed method achieves high accuracy prediction with limited data and has important significance for the health management of PEMFC.

Status of SOC Development at Chaozhou Three-Circle

Chaozhou Three-Circle (Group) Co., Ltd. (CCTC) is a leading company in development and manufacturing of electronic and ceramic components. CCTC has been focusing on SOFC R&D and manufacturing since 2004, covering the complete value chain from powder to power. Based on anode-supported cell technology (ASC in fuel cell mode), the C2-stack in planar design using metallic interconnect exhibits a high efficiency of more than 69% (DC, LHV) at 1.5 kW. Long-term stack tests using pipeline natural gas have been conducted for 20,000 hours, with low degradation rates of below 0.4%/kh.

Performance and Degradation of Electrolyte Supported SOECs with Advanced GDC Thin-film Layers in Long-term Stack Test

Electrolyte supported Solid Oxide Cells (ESCs) with advanced thin-film Gd-doped ceria layers deposited via EB-PVD method at 600 oC were assembled and electrochemically investigated in a so-called “rainbow” stack with 30 repeat units (RUs). At the initial stage of the SOEC operation, the stack reached a high performance with an electrical efficiency of 99.65 % at 75 % steam conversion and a total power input of 1.98 kW. A long-term stack test was performed in SOEC mode for over 5000 h and demonstrated a low voltage degradation of approx. +10.9 mV·kh–1 per RU (+0.9% kh–1). The RUs with EB-PVD GDC thin-films demonstrated similar initial performance and degradation rate to the state-of-the-art cells. In this paper, the investigation mainly focuses on the electrochemical characteristics of RUs containing the EB-PVD thin-film GDC layers.

Emission characteristics of condensable particulate matter (CPM) from FCC flue gas

Particulate matter (PM) as a major air pollutant, generally includes filterable particulate matter (FPM) and condensable particulate matter (CPM). CPM has gradually attracted widespread attention recently, due to its increasing proportion in total PM emissions. Fluid catalytic cracking (FCC) units, the main emission source in refineries, mostly use wet flue gas desulfurization (WFGD), which will produce a large amount of CPM. However, CPM emission and composition of FCC units are actually unclear. In this work, we aimed to understand the emission characteristics of CPM in FCC flue gas and provide some potential control strategies. Here, the stack tests of three typical FCC units were conducted to monitor FPM and CPM, and the field monitoring FPM results are higher than the concentration provided by Continuous Emission Monitoring System (CEMS). The emission of CPM is at a high-level concentration from 28.88 to 86.17 mg/Nm3, divided into inorganic fraction and organic fraction. The inorganic fraction is mainly composed in CPM, where water-soluble ions including SO42−, Na+, NH4+, NO3−, CN−, Cl−, and F−, are the major contributors. Moreover, a variety of organic compounds are detected as qualitative analysis of organic fraction in CPM, which can be roughly classified into alkanes, esters, aromatics, and others. Finally, on the basis of the understanding of the characteristics of CPM, we have proposed two strategies for CPM control. This work is expected to advance CPM emission regulation and control in FCC units.

Анализ систем обеспечения безопасности стендовых испытаний энергоустановок на основе топливных элементов, применяемых на автомобильном транспорте

A theoretical analysis is given related to the ways to reduce the negative impact of motor vehicle exhaust gases on the environment. The possibility of using hydrogen as an energy source for an electric power plant used in the road transport is considered. The operation of a high-power fuel cell battery is advisable on both passenger cars and trucks. However, such technologically complex systems require additional tests at the development stage for verifying the fire safety and tightness of the structure. The systems of storage, transportation, preparation of hydrogen and safety assurance during the performance of such bench tests are analyzed. Fuel cell stack test benches must be provided with additional protection against occurrence of fires and explosions. It is based on a gas-analytical fiber-optic resonant (vibration frequency) sensor that monitors the accumulation of explosive gases. The key parameters of this system are the inertness and speed of the individual elements. A block diagram of a test bench for a fuel cell stack with a power of 150 kW is presented, the hydrogen pressure is reduced to 2–2.5 atm. During the operation of the installation, it is required to ensure continuous monitoring of the pressure in the system and in its individual parts, as well as to monitor the temperature regime of the gas supply in the fuel cell itself. The description of the principle of the test stand functioning is given. Its technological modules are identified, such as a hydrogen supply system, a cooling system, an air injection system, a power plant, and a block for simulating a potential load on an electric motor of the vehicle.

Emission characteristics of benzene series in FCC flue gas

Benzene series are considered as air pollutants in refineries. However, the emissions of benzene series in fluid catalytic cracking (FCC) flue gas are poorly understand. In this work, we conduct stack tests on three typical FCC units. Benzene series, including benzene, toluene, xylene and ethyl benzene, are monitored in the flue gas. It shows that the coking degree of the spent catalysts affect the emissions of benzene series significantly, and there are four kinds of carbon-containing precursors in the spent catalyst. A fixed-bed reactor is used to conduct the regeneration simulation experiments, and the flue gas is monitored by TG-MS and FTIR. The emissions of toluene and ethyl benzene are mainly emitted in the early and middle stage of the reaction (250–650 °C), while the emission of benzene is mainly detected in the middle and late stage of the reaction (450–750 °C). Xylene group is not detected in the stack tests and regeneration experiments. Higher emissions of benzene series are released from the spent catalyst with lower C/H ratio during regeneration process. With the increase of oxygen content, the emissions of benzene series decrease, and the initial emission temperature is advanced. These insights can improve the refinery's awareness and control of benzene series in the future.

Emission factors of industrial boilers burning biomass-derived fuels

ABSTRACT Boilers are combustion devices that provide process heat and are integral to many industrial facilities. Historically, outside of the pulp and paper industry, most boilers burned fossil fuels, although interest in decarbonization has been leading to an increased use of renewable fuels in boilers. These boilers, including those in the biorefineries, are often large sources of air pollutant emissions, and the characterization of these emissions is critical to obtaining air permits and ensuring protection of the surrounding air quality. Several industrial boilers and new biorefineries allow utilization of biomass-derived fuels (e.g. wastewater sludge, lignin, etc.) produced during their operation as a fuel for the boiler to meet process energy needs. However, there is limited empirical data on emission factors for the burning of unconventional fuels, such as solid-gas mixtures containing biomass residues. To fill this gap, we carry out a comprehensive data survey, collecting information on emission factors for boilers burning either a single or a mixture of solid and gaseous biomass-derived fuels. We review multiple hard-to-obtain and unconventional data sources, such as air permit applications, stack test data, and industry-sponsored data collection efforts, to compile emission factors for biomass-derived fuels. We then compare this data with wood residue emission factors from the U.S. Environmental Protection Agency’s AP-42 emission factor database. Our results indicate that the emission factors for boilers burning unconventional fuels vary widely depending on the fuel composition, boiler type, and fuel characteristics. Overall, we find that median emission factors of selected biomass-derived fuels are typically lower than those of wood residue boilers in AP-42. The information collected herein could be useful to permitting agencies and industries utilizing boilers who may want to reduce the carbon impact of their facilities by combusting biomass-derived wastes for process energy needs, for more accurate emission estimation for permitting. Implications: Emission factors are often used for air permitting, specifically for emission estimation purposes. This study carries out a comprehensive data survey of emission factors burning unconventional biomass-derived fuels from underutilized sources such as air permits, stack test data, and industry-led efforts, and compare the results to EPA’s wood residue emission factor database. The results from this study can be used can be used by multiple stakeholders such as air permitting agencies, industries burning biomass-derived fuels, and biorefineries, that utilize more advanced boiler technologies. The findings can help mitigate risks to industry owners and operators and helps to avoid delays in obtaining the required air permits that arise due to inappropriate emission estimates in permit applications.

Study on the Force Characteristics of Aviation Fuel Pipeline under Soil Occupancy Load

Aviation fuel pipeline is one of the important lifelines of aviation coal supply at airports. When crossing a densely populated area, the aviation oil pipeline will inevitably be disturbed by natural and human factors, such as unreasonable soil accumulation near the pipeline, when the soil load is too large, the weak foundation soil will produce different degrees of deformation, the pipeline is subjected to various complex force forms under the action of soil displacement, resulting in a series of damage to the pipeline, and eventually cause pipeline safety accidents, resulting in the loss of people’s lives and property and environmental damage. Therefore, studying the force characteristics and safety prevention and control countermeasures of buried aviation oil pipelines under the surrounding soil pile occupation pressure has a very important guiding role and practical value for ensuring the operation safety of the airport lifeline. In this paper, the stress and deformation of buried oil and gas pipelines under the action of surrounding soil piles are analyzed, the influencing factors of buried oil and gas pipeline stress under the action of soil accumulation are analyzed by finite element software ABAQUS, the detailed stress analysis of the pipeline is carried out,and the finite element simulation method is verified by on-site large-scale stacking tests.

Automotive Fuel Cell Systems: Testing Highly Dynamic Scenarios

PEM fuel cell systems face highly dynamic load profiles in automotive application. This work showcases the impact of media supply adaption, system architecture and test rig restrictions on the transient voltage response of an automotive fuel cell stack. Current step and load profile experiments were conducted on a system test rig, featuring automotive balance of plant components, and a short stack test bench. A time scale analysis allowed us to identify the predominant effect for the voltage response in each test case. The voltage response measured in the test cases was dominated either by air supply, membrane humidification or coolant temperature dynamics. This systematic comparison of different types of test setups highlights the importance of application-like system level testing as, in contrast to common experiments, different phenomena shape the electrical stack behavior.

Harmful effects of lithium-ion battery thermal runaway: scale-up tests from cell to second-life modules.

For a comprehensive safety assessment of stationary lithium-ion-battery applications, it is necessary to better understand the consequences of thermal runaway (TR). In this study, experimental tests comprising twelve TR experiments including four single-cell tests, two cell stack tests and six second-life module tests (2.65 kW h and 6.85 kW h) with an NMC-cathode under similar initial conditions were conducted. The temperature (direct at cells/modules and in near field), mass loss, cell/module voltage, and qualitative vent gas composition (Fourier transform infrared (FTIR) and diode laser spectroscopy (DLS) for HF) were measured. The results of the tests showed that the battery TR is accompanied by severe and in some cases violent chemical reactions. In most cases, TR was not accompanied by pre-gassing of the modules. Jet flames up to a length of 5 m and fragment throwing to distances to more than 30 m were detected. The TR of the tested modules was accompanied by significant mass loss of up to 82%. The maximum HF concentration measured was 76 ppm, whereby the measured HF concentrations in the module tests were not necessarily higher than that in the cell stack tests. Subsequently, an explosion of the released vent gas occurred in one of the tests, resulting in the intensification of the negative consequences. According to the evaluation of the gas measurements with regard to toxicity base on the "Acute Exposure Guideline Levels" (AEGL), there is some concern with regards to CO, which may be equally as important to consider as the release of HF.

Experimental study on the effect of flow channel parameters on the durability of PEMFC stack and analysis of hydrogen crossover mechanism

Polymer electrolyte membrane fuel cell (PEMFC) is a leading technology with a bright future in the field of transportation. The bipolar plate structure has a profound impact on the mass and heat transfer of PEMFC. In this study, the durability tests of two stacks with different channel depths are carried out for 1000 h respectively on the 1 kW fuel cell stack test platform. We detect the overall performance change of the stack and characterize the membrane electrode assembly at the end of the test. Based on the first principle calculation, the mechanism of membrane degradation and hydrogen crossover is analyzed, and some durability experimental results are explained. The results show that the durability of the PEMFC with a shallow flow channel is worse, the voltage drops significantly, and the hydrogen crossover increases significantly after 500 h. The first principle calculation results reveal that the chemical structure change of the membrane is caused by the free radical attack. Hydrogen crossover promotes ∙H to attack carbon-fluorine bonds. This paper reveals the mechanism of hydrogen crossover and its influence on the catalyst layer, which is helpful to improve the durability of PEMFC.

Calibration and Test of Contact Parameters between Chopped Cotton Stalks Using Response Surface Methodology

The accuracy of the material parameter settings directly affects the reliability of the results of the discrete element method simulation. It is necessary to calibrate the relevant parameters to obtain accurate discrete element simulation results when separating the cotton stalk particles from the residual film after crushing. The repose angle of the chopped cotton stalk particles was used as the response value to calibrate the contact parameters between particles. Physical tests measured the intrinsic particle and contact parameters between the cotton stalk particles and the contact material, which provided data for the simulation tests. According to the biological structure characteristics of cotton stalk, the discrete element method model of cotton stalk particles was constructed by bonding the elements of nonequal-diameter basic particles. Based on the response surface methodology, the stacking test of particles was simulated. The response model between the contact parameters and repose angle was established, and the effect law of the single-factor terms and interaction terms on the repose angle was analyzed. The optimal combination of contact parameters was obtained through the single-objective and multi-variable optimization methods. Finally, the contact parameter combination was verified by a simulation test of the repose angle. The results showed that the average relative error of the repose angle between the simulation test and the physical test was 1.04%, which verified the accuracy of the calibrated contact parameters and the reliability of the simulation test. These parameters provide a basis for the discrete element simulation study of cotton stalk motion in the separation process of cotton stalks and residual film and the subsequent gas–solid coupling simulation research.

High Power Density Automotive Membrane Electrode Assemblies

The European GAIA project focussed on the development of novel ionomer, membrane, reinforcement, catalyst, catalyst support, gas diffusion and microporous layers, and layer constructions for high power density, high current density automotive membrane electrode assemblies (MEAs). Reaching a sufficiently low degradation rate (11-14 µV/h in an automotive drive cycle including operation at 105 °C) consistent with the 6,000 hour lifetime target while also succeeding in achieving the 1.8 W/cm2 power density at high current density (3 A/cm2) target was a major challenge, and the outcomes of GAIA represent an important step forward for fuel cell transport MEA technology. The results are all the more important that they were obtained with MEAs using materials developed and up-scaled in GAIA. By reaching this high-power density without increasing platinum loading, the Pt-specific power density was reduced to 0.25 g Pt/kW. Costs analysis demonstrated that recycling (catalyst and ionomer) has the potential to significantly reduce MEA cost, and that, with this, the cost per kW of the high power density GAIA MEAs approaches the 6 €/kW target. This presentation will outline the main materials development steps, summarise testing protocols and the results of automotive size cell short stack tests. Acknowledgement. This project has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking (now Clean Hydrogen Partnership) under grant agreement n°826097. This Joint Undertaking receives support from the European Union’s Horizon 2020 Research and Innovation program, Hydrogen Europe and Hydrogen Europe Research.

Eco-friendly additive construction: Analysis of the printability of earthen-based matrices stabilized with potato starch gel and sisal fibers

• A prototype 3D printing system for construction ecofriendly composites was developed. • A printable composite made with soil, starch gel, and fibers was designed. • The inclusion of starch gel positively affects properties in fresh and hardened state. • The incorporation of sisal fibers allow controlling shrinkage cracking in printed filaments. 3D printing for construction purposes is a disruptive technology with the potential for rapid and massive applications making it a feasible alternative for social housing, temporary shelters after disasters, and, recently, for extraterrestrial habitats. However, most of the matrices used for construction by 3D printing are based on hydraulic cement as the main constituent, which is not easily available in remote locations and is an important greenhouse gases generator. Therefore, a good understanding to formulate and evaluate alternative matrices using soil and organic materials with the required fresh and hardened-state properties compatible with this emerging technology is needed. This article studies the printable capabilities of eco-friendly earthen-based matrices which uses potato starch as a natural stabilizer for raw soil mortars aiming to obtain 3D printed filaments with adequate fresh and hardened-states properties. The aqueous starch gel was combined with sisal fibers in the printing mixture to control shrinkage cracking problems during hardening. The optimization of the dosage of the stabilizer was carried out considering different tests in fresh and hardened printed filaments namely, pumpability and extrudability, stacking, shear vane, shrinkage cracking, Vicat needle, compression strength, and capillarity absorption tests. The results indicate that printable earthen-based matrices reinforced with 1 % of sisal fibers by weight of soil and stabilized with aqueous starch gels with concentrations up to 5 % (w/w) showed improved workability and minor cracking and can be used for 3D printing. These promising results in the field of material science combined with novel 3D printing technology that is also presented in the article open new lines of research for eco-friendly alternatives for the construction industry.

A review of accelerated stress tests dedicated to proton exchange membrane fuel cells – Part I: Fuel cell component level

Various research are currently done about fuel cells. They can concern the application context, the fuel cell technology by itself or the socio-economic bolts. This paper deals with fuel cells stack testing and especially the accelerated stress testing. Long and expensive ageing tests are performed to study the behavior of the fuel cell with the aim of making it as robust as possible versus permanent degradation over time. Accelerated stress tests should provide results faster as classical ageing tests, thus inducing cost reduction. This paper reviews fuel cell component degradation, including degradation mechanisms, and the accelerated stress tests dedicated to all the constituting components (catalyst layer, membrane, gas diffusion layer and bipolar plates). Obviously, the harmonized accelerated stress tests given by the Department of Energy (DoE) are presented but all other recent accelerated test protocols proposed in the literature are also reviewed. In addition, several tables are given to detail operating conditions, specimen, characterization planning and a degradation rate that will be relevant and helpful to converge with an optimal AST solution.

Unsteady 3D-CFD Simulation of a Large Active Area PEM Fuel Cell under Automotive Operation Conditions—Efficient Parameterization and Simulation Using Numerically Reduced Models

Polymer electrolyte membrane fuel cells (PEMFC) are promising devices for securing future sustainable mobility. Their field of application ranges from locally emission-free stationary power generation to propulsion systems for vehicles of all kinds. Computational fluid dynamic (CFD) simulations are successfully used to access the internal states and processes with high temporal and spatial resolution. It is challenging to obtain reliable physical values of material properties for the parameterization of the numerous governing equations. The current work addresses this problem and uses numerically reduced models to parameterize sophisticated transient 3D-CFD models of a commercial PEMFC. Experimental data from a stack test stand were available as a reference for numerical optimization of selected parameters and validation purposes. With an innovative meshing approach, the homogenized channels approach, a reduction of computational cells by 87% could be achieved, thus enabling the unsteady simulation of a 120 s load step with a computational mesh that represents the entire fuel cell geometry with reasonable computational effort. The water formation and the transport processes during the load step were analyzed. The self-humidification strategy of the fuel cell gases was visualized and the uniformity of the simulated quantities was discussed. An outlook on possible future work on efficient parameterization is given.

(Invited) Durability of Electrolyte Supported Solid Oxide Cells for Steam Electrolysis: Results from Cell Testing in the 20,000 h to 50,000 Hours Range

There is a current fast development of water/steam electrolysis for the production of hydrogen from renewable energy sources. (Multi) MW power demonstration units using the different (low and high temperature) technologies are, e.g., subject of the R&D project H2Giga funded by the German Federal Ministry of Education and Research /1/. Steam electrolysis with solid oxide cells (SOC) is characterised by a high energy-conversion efficiency, notably if steam is available, such as via a heat source of moderate temperature for steam generation. Approaches for a matching to a fluctuating load, important in the context of operation with renewable energy sources, are also under development with the SOC technology /2/.For the SOC electrolysers, durability analysis of the cells in a time scale appropriate for application remains an important development step. Cell (or short stack) testing allows a rather precise control of the cell temperature which facilitates quantification of degradation for the practically required degradation rates well below 10 mV/1000 h (cf. /3/). In this contribution, our testing results will be updated, with up to about 50,000 h operation using electrolyte supported cells (ESC) with Ni/GDC hydrogen electrodes and different types of electrolyte (10Sc1CeSZ, 6Sc1CeSZ, 3YSZ). As reference for cell durability serves a 23,000 h steam electrolysis test with a cell with 6Sc1CeSZ electrolyte /4/. However, cells with the known robust 3YSZ electrolyte seem to yield a comparably low long-term degradation, together with better initial stability /5/. The use of an electrolyte of high ionic conductivity, 10Sc1CeSZ, allows a relatively low initial temperature (<800°C) for a cell voltage close to the thermal neutral voltage for 0.6 Acm-2 current density. This, in turn, leaves a wide temperature margin for compensation of voltage degradation via a temperature increase (cf. initial period of the test in /3/). The results from the durability tests serve as examples for a large degree of SOFC/SOEC reversibility achievable with the ESC. Moreover, the relatively thick electrolyte layer of the ESC with its large ohmic resistance comes along with a high ohmic contribution in the overall degradation in most tests. The different degradation contributions were separated with in-situ impedance spectroscopy without interrupting the DC current flow.

High-Pressure PEMWE Stack and System Characterization

As the urgency to decarbonize the industry and transport sector intensifies, renewable energy-based hydrogen production via advanced low temperature water electrolysis is attracting increased interest. Proton exchange membrane water electrolysers (PEMWE) offer several benefits over the more mature alkaline water electrolysis technology, including its load-following capability and the ability to operate at higher pressures. The latter is important because significant benefits can be harvested by adopting systems operating at pressure-levels compatible with the end use applications and thereby render the mechanical compressor redundant. At IFE we have developed a methodology which encompasses detailed energy- and techno-economic calculations of high-pressure systems, and a comparison between high-pressure electrolysis and state-of-the-art electrolysis at 30 bar in combination with a compressor has been carried out. Here, direct pressurization to 80 and 200 bar (relevant for, e.g., methanol and ammonia production) was found to be economically viable.To realize high-pressure H2 generation systems, many challenges related to system operability, efficiency and safety needs to be addressed. As part of the national infrastructure “The Norwegian Fuel Cell and Hydrogen Centre”, Institute for Energy Technology (IFE) has installed a flexible PEM water electrolyzer system platform for testing of small-scale prototype electrolyzers up to 33 kW and 200 bar differential pressure. The test rig is integrated with a sophisticated power conditioning system which consists of three custom-built DC/DC-converters (for PEMWE, PEMFC, and Li-ion battery systems), all coupled to the same DC-bus. This configuration makes it possible to test different hybrid electric topologies and to emulate different loads (e.g., grid load profiles, wind generation). This one-of-a-kind high-pressure PEMWE test facility at IFE is well suited to study performances of next-generation PEMWE stacks and systems, and to tailor and test control strategies that safeguards the system and maximizes efficiency and durabilityThe test rig has been commissioned with a prototype high-pressure stack with a production capacity of 2 Nm3/h (Nel Hydrogen), and the identified economically viable pressure range of 80-200 bar has been the main target for an experimental test campaign. The experimental results are presented from stack testing including polarization curves and EIS data as a function of temperature, pressure and current density. The results are discussed in relation to the techno-economic model, in order to identify pathways towards more efficient hydrogen production. Figure 1

Calibration and Experimental Validation of Contact Parameters in a Discrete Element Model for Tobacco Strips

To study the contact parameters of the tobacco strips during redrying, in this study, the funnel stacking test is used to determine the stacking angle, and the discrete element method is used to simulate the formation process of the stacking angle, to calibrate and verify the physical and contact parameters of tobacco strips. The Placket–Burman test was used to screen out the parameters that had significant effects on the stacking angle. The regression response surface model between the stacking angle and contact parameters was established by Central Composite Design using the stacking angle from physical tests as the response index. The test results show that static and rolling friction coefficients between tobacco strips have significant effects on the test results, so these two parameters must be accurately calibrated. Finally, the accuracy and validity of the calibrated tobacco strips contact parameters were verified by comparing the stacking angle and void ratio of physical and simulation experiments. The calibration results can provide basic parameters for studying the interaction and motion of the tobacco strips in the redrying process using simulation methods.

ESTABLISHMENT AND CALIBRATION OF DISCRETE ELEMENT MODEL OF KING GRASS STALK BASED ON THROWING TEST

In order to better use the discrete element method (DEM) to study the cutting and throwing process of King Grass (KG) stalk in mechanical harvesting, the DEM model and contact parameters of KG stalk were studied in this paper. By using the Multi-sphere method, the DEM model of KG stalk was established in EDEM software. Through the impact bounce test and slope sliding test, the stalk-steel coefficient of static friction, stalk-steel coefficient of restitution and stalk-stalk coefficient of restitution were calibrated as 0.372, 0.656 and 0.523, respectively. Based on the stacking test, using the response surface methodology, the optimal values of stalk-stalk coefficient of static friction, stalk-stalk coefficient of rolling friction, stalk-steel coefficient of rolling friction were calibrated as 0.393, 0.072 and 0.144, respectively. The throwing test bench of stalk was designed, and the actual and simulation throwing test were carried out. The relative error of throwing distance in bench test and simulation test under four throwing speeds was 1.15%, 7.76%, 8.88% and 10.46%, respectively. The throwing trajectory curve of the simulation test is consistent with that of the actual test, which verifies the accuracy of the DEM model and contact parameters of KG stalk.