Abstracts and Key Words
2021-12-08
HeatSourceandColdSource
CaseAnalysisofAbsorptionHeatPumpAppliedinWasteHeatRecoveryofBoilerFlueGas
KE Guohua
Abstract: Six lithium bromide absorption heat pumps from five heating projects are selected as cases to test the recovery of flue gas waste heat from gas-fired boilers and analyze the operation effect of heat pumps. Among the six heat pumps,the COP of five heat pumps is close to or exceeds 1.6,the proportion of waste heat recovery of boiler flue gas reaches more than 60%,and the operation effect of heat pump is good. The COP of the other heat pump is only 1.3,and the proportion of waste heat recovery of boiler flue gas is 39.56%,which fails to realize the effective recovery of waste heat of flue gas. Through the test and analysis,it is concluded that the COP of the heat pump can effectively reflect the operation effect of the heat pump. There is a more suitable range for the proportion of flue gas waste heat recovery,not the higher the better.
Keywords: LiBr absorption heat pump;gas-fired boiler;flue gas waste heat recovery
SimulationStudyonAnnularPulseJetAshCleaningofFilterCartridgeDustCollector
NIU Bingbing,FAN Yuesheng,LI Zheran,TIAN Guoji,ZHANG Xin,LIU Ting,WU Shuheng
Abstract: The pulse jet ash cleaning process of the filter cartridge dust collector is introduced,the ash cleaning performance of the annular pulse jet is simulated,and it is compared with the circular pulse jet ash cleaning method. Compared with the annular jet,the entrainment effect of the circular jet is very weak,and the airflow entering the filter cartridge is basically a primary airflow blown from the nozzle. The symmetry of the airflow is poor,and the phenomenon of airflow eccentricity is easy to occur,resulting in a high airflow speed on one side of the filter cartridge,excessive dust removal,and poor dust removal effect on the other side. The range of airflow is small (in the radial direction of the filter cartridge),and the airflow is directly sprayed to the bottom of the filter cartridge along the axis of the filter cartridge,and does not move forward along the wall of the filter cartridge. When the annular jet method is adopted,the area of the negative pressure zone at the inlet of the filter cartridge is much smaller than that of the circular jet method,the pressure change in the axial direction of the filter cartridge is slower,and the pressure distribution along the radial direction of the filter cartridge is more uniform. The dust removal uniformity of the annular jet method is better.
Keywords: filter cartridge dust collector;pulse jet ash cleaning;annular jet;circular jet
SelectionofThermodynamicModelofR134a-DMFAbsorptionRefrigerationSystem
CHEN Xin,LI Hui,SHAN Mingzhu
Abstract: Taking R134a-DMF binary solution as the research object,based on Aspen Plus software,the selection of the thermodynamic model for the binary solution is studied at the temperatures of 303.3 K and 353.24 K and the pressure range of 0 to 2.7 MPa. Firstly,three kinds of thermodynamic models of PENG-ROB,NRTL and PRMHV2 applicable for the r134a-dmf system are preliminarily determined according to the thermodynamic model decision tree. Then,based on Aspen Plus software,three kinds of models are regressed respectively through the gas-liquid equilibrium experimental data of the R134a-DMF binary solution. Taking the average relative error of pressure as the evaluation index,the regression results show that the average relative error of pressure in the thermodynamic model of PENG-ROB is the smallest. The regression model of PENG-ROB is applied to the absorption refrigeration system of R134a-DMF,and the binary interaction parameter after regression is -0.000 138 782,which can meet the needs of phase equilibrium description of R134a-DMF.
Keywords: R134a-DMF working fluid pair;thermodynamic model;PENG-ROB model;NRTL model;PRMHV2 model
ElectricitySavingandEmissionReductionEffectofWasteHeatRecoveryofScrewAirCompressor
JIA Jianbo
Abstract: The principle and influencing factors of waste heat recovery of screw air compressors are introduced. Combined with engineering examples,the electricity saving and emission reduction effects of the screw air compressor waste heat recovery system used to prepare hot water for bathing in factory dormitories are discussed. The original plan uses a water source heat pump unit to prepare bathing hot water,and the transformed plan is based on the original plan with a screw air compressor waste heat recovery system in parallel. The screw air compressor waste heat recovery system is the main heating system. When the capacity is insufficient,the water source heat pump unit is used as a supplement. After the transformation,the annual electricity saving rate is 59.96%,and the annual carbon dioxide emission reduction is 442.86 t.
Keywords: screw air compressor;waste heat recovery;electricity saving;emission reduction
HeatingNetwork,Cooling-supplyNetworkandHeatingStation
FeasibilityAnalysisofReturnWaterBoosterPumpDrivenbyHydraulicTurbine
LI Haidong
Abstract: Aiming at a long-distance heat transmission network with large height difference,the scheme for recovery of the residual pressure of the water supply pipe network with hydraulic turbine (replacing pressure insulation heating station) to drive the return water booster pump is proposed,and the technical and economical comparison is made with the scheme for setting up a pressure insulation heating station. The starting point of the heating network is the first station of the thermal power plant,and the ending point is the urban boundary. At the end of the pipe network,the No. 1 pressure insulation heating station is indirectly connected to the urban pipe network. Scheme 1: the hydraulic turbine is set to drive the No. 2 return water booster pump. Scheme 2: the hydraulic turbine and electric motor are set to drive the No. 2 return water booster pump. Scheme 3: the No. 2 pressure insulation heating station is set. The supply and return water temperatures at the low temperature side of No. 1 pressure insulation heating station are 125 ℃ and 30 ℃ in schemes 1 and 2,and 120 ℃ and 25 ℃ in scheme 3. When the mass flow of hot water is constant,the heating capacity of each scheme is basically the same. The power consumption of schemes 1 and 2 is the same,and the power consumption of scheme 3 is 8.6% higher. Compared with the conventional pressure insulation heating station,the hydraulic turbine room has less equipment such as heat exchangers and decontamination devices,and it occupies a smaller area. There are more pipe network valves and control nodes for setting up hydraulic turbines,which poses a greater safety risk compared with pressure insulation heating station.
Keywords: hydraulic turbine;long-distance heat transmission network;residual pressure recovery;pressure insulation heating station
BuildingHeating,AirConditioning,VentilationandThermalEnvironment
SimulationofDirectCoolingSystemofBuriedPipeHeatExchangerinHotSummerandColdWinterAreas
BAO Xiaofeng,HU Pingfang,ZHU Na,LEI Fei,XING Lu,WANG Jiandong,YANG Yang,LIN Zudong
Abstract: Taking an office room in Wuhan as the simulation object,the simulation method is used to study the applicable time (the predicted mean vote (PMV) is greater than -1.5 and less than 1.5) of the buried pipe heat exchanger direct cooling system (capillary radiant cooling system at the end) during working hours of the cooling period in the hot summer and cold winter areas. The same simulation method is used to determine the applicable time during working hours of the cooling period in hot summer and cold winter cities such as Hefei,Nanchang,Shanghai,Nanjing and Hangzhou. For Wuhan,the average indoor temperature during the cooling period is 28.2 ℃. During the working hours of the cooling period,the indoor temperature is lower than 27 ℃ for 350 hours,which are distributed in the initial and final stages of cooling period: 208 hours in the initial stage of cooling period and 142 hours in the final stage of cooling period. During the working hours of the cooling period,the average inlet water temperature of the capillary is 22.2 ℃,the average outlet water temperature is 23.7 ℃,and the average inlet and outlet water temperature difference is 1.5 ℃. Taking PMV as the evaluation index,the working hours of the cooling period are applicable time for 359 hours,most of which are distributed in the initial and final stages of cooling period: 279 hours in the initial stage of cooling period and 79 hours in the final stage of cooling period. For Hefei,Nanchang,Shanghai,Nanjing and Hangzhou,using PMV as the evaluation index,most of the applicable time during working hours during the cooling period are distributed in the initial and final stages of cooling,and the applicable times are 358,281,495,436 and 429 hours respectively.
Keywords: buried pipe heat exchanger;direct cooling;capillary radiant cooling and heating;hot summer and cold winter area;office building
RenewableEnergy,DistributedEnergySourceandCombinedCooling,HeatingandPower
DevelopmentStatusQuoofForeignHydrogenEnergyandItsEnlightenmenttoChina
JIANG Xin,QIAO Jia,JIN Wenlong,DING Bin
Abstract: The development of hydrogen energy in the United States,Europe and Japan is analyzed from two dimensions of policy and industrial development mode. Some suggestions on the development of hydrogen energy industry in China are put forward: perfecting the top-level design of hydrogen energy industry and doing well in industrial planning;paying attention to the research and development of independent core technologies and products in hydrogen energy industry chain;strengthening the standard construction and perfecting the standard system of hydrogen energy industry chain.
Keywords: abroad;hydrogen energy development current status;policy;industrial development mode
EconomyofSolidOxideFuelCellandHouseholdCombinedHeatandPower
JIN Wenlong,JIANG Xin
Abstract: The research and application progress of solid oxide fuel cells in the United States,Japan,Germany and China are introduced. The economy of household solid oxide fuel cell combined heat and power system in Japan (taking single-family households of four people in the Kansai region as examples) and China (taking urban residents in Beijing as examples) is calculated and analyzed. According to the literature,the solid oxide fuel cell combined heat and power system is relatively economical in Japan. Compared with the conventional domestic energy supply methods in Japan (gas heater heating and grid power supply),the annual operating cost of the solid oxide fuel cell combined heat and power system can be reduced by 12.8×104yen. The cost of the solid oxide fuel cell combined heat and power system is estimated at 100×104yen,and the static difference investment payback period is 7.8 years. According to the calculation results,compared with the conventional domestic energy supply methods in China (gas water heaters for producing domestic hot water and grid power supply),the annual operating cost of the solid oxide fuel cell combined heat and power system can be reduced by 521.26 yuan. Under the premise that the cost of the solid oxide fuel cell combined heat and power system is 9.24×104yuan,the static difference investment payback period is longer than the device life (10 years). At this stage,the economy of solid oxide fuel cell combined heat and power system is not ideal in China.
Keywords: solid oxide fuel cell;household combined heat and power;economy
NoiseControlDesignofHospitalNaturalGasDistributedEnergyStation
YI Wenqing
Abstract: Combined with an engineering example,the noise control design of hospital natural gas distributed energy station is discussed. Noise control objects mainly include energy station buildings,internal-combustion gas engine generator sets,energy station mainframe rooms,water pumps and cooling towers. The design of the silent cover for internal-combustion gas engine generator set is analyzed. The measured values of noise at the boundary of the energy station (46 to 54 dB in the daytime and 35 to 45 dB at night) meet the requirements ofEmissionStandardforIndustrialEnterprisesNoiseatBoundary(GB 123482008).
Keywords: natural gas distributed energy station;hospital;noise control
TechnicalApplicationofBiomassHeatandPowerCogenerationSystem
YANG Bin
Abstract: Taking a biomass heat and power cogeneration system project in Qingdao as an example,the system process and the performance of biomass briquettes are introduced. The technical improvement measures are proposed,and the environmental protection effects are analyzed.
Keywords: biomass;heat and power cogeneration;biomass briquette;improvement measures;environmental protection effect
OverseasHeating
CentralHeatingTechnologyandTypicalCasesinFinland
ZHANG Qi,GUO Weijie,GU Yajun
Abstract: The central heating technology and typical cases in Finland are introduced,and the characteristics of Finnish energy mode are analyzed. It is pointed out that the multi-heat source networking,ring-shaped pipe network,building heating station,and database establishment are worthy of reference.
Keywords: central heating in Finland;energy mode;building heating station
GasCombustion,GasAppliancesandGasConsumptionEquipment
ResearchonLowNOxEmissionfromBurnersofSingleWellGasHeatingBoilers
ZHOU Hongbin,SONG Chunyan,YANG Baogang,ZHOU Lei,ZHAO Jingang,CHANG Feng,SUN Encheng
Abstract: Literature analysis and combustion mechanism research on natural draft diffusion burner of 50 kW single well gas heating boiler are carried out. Combined with CFD numerical simulation,the NOxand CO emissions of natural draft diffusion burner under different excess air coefficients are calculated,and the technical requirements of NOxemissions and low nitrogen emissions of fully premixed burner under different excess air coefficients (gas-air mixture temperature is 27 ℃) and different initial mixture temperatures (excess air coefficient is 1.5) are analyzed. The analysis results show that the pollutant emissions of natural draft diffusion burner cannot meet the current requirements,and the fully premixed combustion technology is more suitable for the low nitrogen transformation of small single well gas heating boiler. In the burner transformation,the fully premixed burner should meet the technical requirements of stable operation under high excess air coefficient and good mixed gas heat insulation.
Keywords: natural draft;diffusion combustion;fully premixed combustion;low nitrogen burner
GasTransmission,Distribution,StorageandTransportation
FaultDiagnosisandEarlyWarningofGasRegulatorBasedonWaveletPacketandAprioriAlgorithm
SUN Mingyuan,HAO Xuejun
Abstract: A fault diagnosis and early warning method of gas regulators based on wavelet packet algorithm and Apriori algorithm is proposed. Firstly,the wavelet packet algorithm is used to analyze the outlet pressure and load pressure of the regulator,and the frequency band energy energy value of each fault type are obtained. Then,the Pearson correlation coefficient method is used to calculate the correlation coefficients between outlet pressure and operating velocity,operating velocity and valve position opening,outlet pressure and load pressure. After transaction type conversion,the Apriori algorithm is used to obtain the strong association rules between multivariable correlation coefficient and fault types. The frequency band energy value obtained by using the wavelet packet algorithm to decompose the outlet pressure and load pressure of the regulator can be used as the basic criterion. The strong association rules between multivariate correlation coefficient and fault type obtained by Apriori algorithm can be used as the key criterion to improve the accuracy of fault diagnosis and early warning model of high and medium pressure gas regulator. The fault diagnosis and early warning model of high and medium pressure gas regulator established by combining wavelet packet algorithm and Apriori algorithm has been verified by practical examples.
Keywords: gas regulator;wavelet packet algorithm;Apriori algorithm;fault diagnosis and early warning
SchemeofPowerSupplyandWasteHeatUtilizationforYanqingGasGateStationinBeijing
CHEN Taotao,SU Zheng,QIAN Di
Abstract: By analyzing the electricity load and available power generation resources of Beijing Yanqing gas gate station,using internal-combustion gas engine power generation,gas pressure energy power generation,solar power generation,wind power generation and power storage system,with the help of intelligent energy management system,a independent micro-grid power supply scheme based on multi-energy complementary and coupling power supply for the gate station design is proposed. In order to make full use of the waste heat generated by micro-grid power supply and reduce the energy consumption of the gate station,a feasible waste heat utilization scheme of the internal combustion engine flue gas and jacket water is designed,and the key heat exchange equipment for waste heat utilization is calculated.
Keywords: no municipal grid gas gate station;multi-energy complementary;coupling power supply;micro-grid power supply;waste heat utilization
ApplicationofLaserMethaneLeakageAutomaticTelemetrySysteminNaturalGasPlantsandStations
MA Jilin
Abstract: The problems existing in leakage patrol inspection of natural gas plants and stations,and the working principle and characteristics of laser methane leakage automatic telemetry system (composed of monitoring cloud platform,explosion-proof control box,control cabinet and workstation) are described. Taking the application of the system in Tianjin Tanggu gas gate station as an example,the automatic patrol inspection line is designed to realize the patrol inspection of the system. Compared with manual patrol inspection,the patrol inspection efficiency is improved.
Keywords: patrol inspection;laser;methane leakage;automatic telemetry system;natural gas plant and station;monitoring cloud platform
AnalysisonGasConsumptionofChangingCoaltoGasinRuralAreaofXingtai
ZHAO Yanling,LI Yonghui,CHENG Xiang,ZHAO Baoxia
Abstract: The gas consumption of coal to gas in rural area of Xingtai (users are equipped with gas stoves and gas-fired heating and hot water combi-boilers) is investigated,and the data are collected and analyzed. The influence of non-human factors and human factors on gas consumption is discussed.
Keywords: Xingtai area;coal to gas in rural area;gas-fired heating and hot water combi-boiler;gas consumption
LiquefiedNaturalGas
FrostingMechanismandControlTechnologyofLNGAirTemperatureVaporizer
HUANG Zhongfeng,WANG Yunhang,ZOU Wei
Abstract: The frosting mechanism of LNG air temperature vaporizer is analyzed. The frosting process is divided into frost crystal growth period,frost layer growth period and frost layer full growth period. The frost layer growth period should be strictly controlled to prevent large area frosting of vaporizer. Sampling is taken at the LNG vaporizing station. Through the actual measurement,the porosity of the frost layer is 6.13%. The influence of air temperature,relative humidity and distance between vaporizers on the frosting of vaporizers is analyzed. Through the actual measurement of the thickness of frost layer,the variation law of the vaporizer frost layer thermal resistance with the influence factors is calculated. It is concluded that the air temperature has the greatest influence on the vaporizer frost layer thermal resistance,so the air temperature around the vaporizer should be strictly controlled. The control measures to reduce the frosting of vaporizer are put forward (using steam to heat the air around the vaporizer,mechanical mist removal,vaporizer spacing control,SCADA intelligent monitoring). The operation practice shows that the frosting phenomenon of vaporizer is effectively controlled after taking control measures,and the thickness and length of frost layer are significantly reduced.
Keywords: LNG air temperature vaporizer;frosting mechanism;thickness of frost layer;thermal resistance of frost layer;frost control measures
DesignMethodofCryogenicPipelineinLNGGasificationStation
JING Shuai
Abstract: Due to the large temperature difference between the the operating conditions and installation conditions of LNG pipeline,compensation measures need to be taken. Taking the cryogenic pipeline in a typical LNG gasification station as an example,the design methods of the trunk,branch and their supports are introduced. The design method of cryogenic pipeline is to initially determine the pipeline and its support according to the process flow,and then use the CAESAR II V2014 software to check and calculate the pipeline stress,displacement,and force acting on the support. In order to ensure that the support does not slip off,it is necessary to comprehensively consider the pipeline displacement and the support selection. Firstly,the support is initially selected according to the pipeline displacement,and then the pipeline displacement is checked in conjunction with the selected support. The compensation interval is calculated according to the allowable pipe displacement of the support,combined with the thermal expansion and cold contraction of the pipeline. Using L-shaped,Z-shaped and square-shaped compensation LNG trunk pipes,the pipeline stress and the load acting on the support are small. The flexibility of the pipeline is related to the natural compensation form. The Z-shape is the best,the L-shape is in the middle,and the square is the worst. For LNG branch,the number of elbows is gradually increased in combination with the results of stress calculations until the maximum stress at the main tee and branch tee is less than the allowable stress. A concave-shaped branch connected to the vaporizer is designed,and the stress calculation results are reasonable.
Keywords: LNG gasification station;cryogenic pipeline;natural compensation;CAESAR II software;stress;displacement
SafeOperationofPipeTrenchinLNGFillingStation
YANG Jun
Abstract: In view of the problems existing in the pipe trench in LNG filling station,such as unbalanced pipeline flow,cold insulation failure and gas leakage of pipeline,displacement of cover plate,poor ventilation in the trench and water accumulation in the trench,the causes are analyzed,and the solutions are proposed.
Keywords: LNG filling station;pipe trench;safe operation;unbalanced flow;cold insulation failure;ventilation;water accumulation
BuildingGasSupply
CharacteristicsandDesignPointsofNaturalGasConsumptioninCommercialComplex
GUO Yangbin,ZHANG Cheng
Abstract: The commercial complex has the characteristics of numerous and scattered restaurants,densely personnel and generally ventilation,complex building structure,and attention to beautiful facade and so on. The gas use characteristics and design points of commercial complex are discussed.
Keywords: commercial complex;gas use characteristics;gas design points
GasEngineeringConstructionandDevelopment
SafetyTechnicalProblemsandCountermeasuresofGasPipelineCrossingRailwayConstruction
XU Longchun
Abstract: Combined with engineering examples,the safety technical problems and countermeasures in construction of the gas pipeline crossing railway and pipe jacking are analyzed.
Keywords: insulating support;stray current;solid decoupler;epoxy glass fiber reinforced plastic
GasInformatization
Three-meterIntegratedReadingSystemBasedonNB-IoTandPLC
WANG Zijing,SHU Qin,YAO Xianwei
Abstract: Based on NB-IoT communication technology and low-voltage power line carrier (PLC) technology,a gas meter,electricity meter and water meter integrated reading system is proposed. The physical architecture and data transmission process of the three-meter integrated reading system are introduced,and the benefit analysis is carried out.
Keywords: three-meter integration;NB-IoT communication technology;low-voltage power line carrier (PLC);data transmission;integrated reading system