HeatSourceandColdSource

ComparisonofHeatingCost
andProjectCostofHeatPump
JIN Yi，WANG Qin

Abstract： The heating costs (only electricity and fuel costs for heat source equipment，not including costs of other auxiliary equipment such as water pumps) of boilers (gas boilers，regenerative electric boilers and biomass boilers) and heat pumps (air source heat pumps，sewage source heat pumps and buried pipe ground source heat pumps) are calculated. The project costs that have been built in Qingdao area are compared. Under the current energy price condition，compared with the three boiler heating methods，the heating costs of the three heat pumps are relatively low. Among the three boiler heating methods，the heating cost of the biomass boiler is the lowest. The unit heating area cost of the same type of heat pump heating method is similar，the unit heating area cost of air source heat pump is the lowest，and the unit heating area costs of sewage source heat pump and buried pipe ground source heat pump are close and higher than that of air source heat pump.

Keywords: heat pump heating；heating cost；project cost；scheme comparison

InfluenceofWater-gasRatioon
PerformanceofFlueGasWasteHeat
RecoverySysteminDirectContact
WANG Xun，LIU Lu，HU Ming

Abstract： For the heating system of gas boiler (rated heat power of 5.6 MW) heating system with direct contact flue gas-water heat exchanger (hereinafter referred to as flue gas heat exchanger) and direct contact air-water heat exchanger，Aspen Plus process simulation software is used to analyze the influence of the flue gas heat exchanger water-gas ratio (the ratio of spray water to flue gas mass flow rate) on the inlet air temperature of gas boiler，the system heating increment and the exhaust temperature of flue gas heat exchanger (that is，the system exhaust temperature). In order to reduce the nitrogen oxide emission and improve the heating capacity of the system，the appropriate water-to-air ratio is determined. According to the results of simulation calculations，the suitable water-gas ratio of flue gas heat exchanger is 3.0.

Keywords: direct contact flue gas-water heat exchanger；water-gas ratio；flue gas waste heat recovery

Heat-supplyNetwork，Cooling-supply
NetworkandSubstation

KeyDesignPointsofLarge
PressureIsolationStation
YU Honghao，LIU Xuedong，LI Fei，
XU Guochun，LI Shuting，ZHANG Wenwen

Abstract： Combined with engineering examples，the key design points of large pressure isolation station are analyzed，including process flow，equipment and pipeline layout，stress calculation，and so on. Large pressure isolation station equipment is large in size and large in diameter. Although adopting three-layer layout reduces the footprint，it puts forward higher requirements for design，construction，overhaul and so on.

Keywords: pressure isolation station；process flow；equipment layout；pipeline layout；stress calculation

CheckingofStraightPipeStability
andElbowStrengthforDirectlyBuried
SteamPipelineOuterProtectivePipe
QIAO Zhengfan，CHE Fengqin，WANG Lei

Abstract： According to the stipulations inTechnicalSpecificationforDirectlyBuriedSteamHeatingPipelineinCity(CJJ/T 104-2014) andTechnicalSpecificationforDirectlyBuriedHot-waterHeatingPipelineinCity(CJJ/T 81-2013)，combined with specific examples，the local stability checking，radial stability checking and elbow (horizontal arrangement) strength checking of straight pipe section of directly buried steam pipeline outer protective pipe are carried out. The treatment method is put forward for the horizontal corner section which does not meet the condition of strength checking.

Keywords: directly buried steam pipeline；outer protective pipe；straight pipe stability checking；elbow strength checking

Thermal-HydraulicResponseSimulation
ofUserEndofSteamPipeline
LU Hai，LUO Enbo，SUN Xinnan，
ZHOU Yi，SU Shi，ZHONG Wei

Abstract： A single steam pipeline transportation dynamic simulation model based on Modelica language was established by comprehensively considering the thermal-hydraulic coupling factors and dynamic characteristics of steam flow in the pipeline. The steam operation parameters (pressure，temperature and mass flow) of a certain section of overhead steam pipeline in a chemical industry park in Shanghai were taken as the model simulation input，the steam operation parameters (pressure and temperature) of the user were simulated and calculated. The simulation values were compared with the measured values to verify the calculation accuracy of the simulation model. The thermal response and hydraulic response of the user end were studied by simulation model. The results of calculation accuracy verification show that the simulation values are in good agreement with the measured values，and the maximum relative error between the simulated value and the measured value of user steam temperature is 3.1%，while the maximum relative error between the simulated value and the measured value of user steam pressure is -0.6%. The calculation accuracy of the simulation model can meet the engineering requirements. For thermal response，the response of user steam temperature obviously lags behind the change of heat source steam temperature，and the steam heat network has strong thermal inertia. For hydraulic response，the user steam pressure responds quickly to the change of heat source pressure，and the user steam mass flow responds quickly to the change of heat source mass flow.

Keywords: steam pipeline；Modelica language；thermal response；hydraulic response

BuildingHeating，AirConditioning，
VentilationandThermalEnvironment

DesignofSolarBiogasComplementary
WaterHeaterSystem
YU Tingting，ZHOU Qian，
JIN Junjie，XING Feifei，MEI Aohan

Abstract： A solar biogas complementary water heater system is designed. This system makes full use of the waste heat of rural bathing water and flue gas and uses gravity heat pipes to recover the heat of the atmosphere to heat the biogas digester，increasing the gas production rate. When solar energy cannot provide enough heat，it is replenished with burning biogas. The principle and process of the system are introduced，and the balance of heat supply and demand is discussed with examples. Comparing the economy of this system with solar water heaters，electric water heaters and air energy water heaters，the economic benefit of this system is obvious.

Keywords: biogas；solar energy；water heater；gravity heat pipe

RenewableEnergy，DistributedEnergy
SourceandCombinedCooling，
HeatingandPower

ApplicationofNaturalGasDistributed
EnergyinGateStation
LAI Jianbo，LI Jianxun，
MA Hongjing，WANG Lin

Abstract： The town gate station is furnished with comprehensive office building，process equipment and auxiliary facilities and so on. Among them，the integrated office building has cold and heat load demand，and the pressure regulating equipment in the process installations has annual heat load demand. The energy demand will be met by building natural gas distributed energy stations. According to the operation principle of power generation and no access the grid，the natural gas distributed energy system and process flow of the gate station are designed. The gas-fired engine generator set is used to generate electricity. The flue gas waste heat of the generator set and the cylinder cooling water waste heat are supplied to the afterburning type lithium bromide absorption heat pump unit for cooling and heating. The cooling capacity can meet the heat load demand. The insufficient power is replenished by the municipal power grid，and the insufficient heating capacity is solved by the lithium bromide heat pump unit through natural gas afterburning to realize combined cooling，heating and power. The hourly load sharing method is used to forecast the annual hourly electric load of the gate station. The DeST software is used to forecast the hourly hot and cold load of the gate station throughout the year. By comparing the operation income of three gas-fired engine generator sets with different capacities，the capacity of the generator set is selected，and the corresponding lithium bromide heat pump unit and water-water heat exchanger are configured. The operation strategy is determined based on the hourly load demand of the gate station for cooling，heating and power. The annual average comprehensive utilization rate of the energy station is 86.3%，and the energy saving rate is 34.3%. The static investment recovery period of the energy station is 5.1 years，which has good economic benefits.

Keywords: gate station；distributed energy；design of energy station；combined cooling，heating and power

CostofHydrogenProductionfrom
FossilEnergyandElectrolyzedWater
ConsideringCarbonEmissions
SHEN Wei，YANG Weiying

Abstract： Considering the carbon emissions，the unit hydrogen production costs of hydrogen production process in fossil energy and electrolyzed water are compared. The fossil energy hydrogen production process includes coal hydrogen production，natural gas hydrogen production and methanol hydrogen production. The electrolyzed water hydrogen production process includes the low valley electricity electrolyzed water hydrogen production using thermal power and renewable energy abandoned electricity electrolyzed water hydrogen production. Sensitivity analysis of hydrogen production cost is carried out by selecting raw material prices，equipment investment，and carbon tax rates as sensitive factors. Before the consideration of carbon tax，the hydrogen production cost from low to high is followed by coal hydrogen production，renewable energy abandoned electricity electrolyzed water hydrogen production，natural gas hydrogen production，methanol hydrogen production and low valley electricity electrolyzed water hydrogen production. After the consideration of carbon tax，the hydrogen production cost from low to high is followed by renewable energy abandoned electricity electrolyzed water hydrogen production，natural gas hydrogen production，coal hydrogen production，methanol hydrogen production and low valley electricity electrolyzed water hydrogen production. For the coal hydrogen production process，the influence degree of sensitive factors is in order of coal price，carbon tax rate and equipment investment，and the influence degree of coal price and carbon tax rate on the cost is basically close. For the natural gas hydrogen production process，the influence degree of sensitive factors is in order of natural gas price，equipment investment and carbon tax rate，and the influence of natural gas price is much greater than the other two sensitive factors. For the methanol hydrogen production process，the influence degree of sensitive factors is in order of methanol price，equipment investment and carbon tax rate，and the influence of methanol price is much greater than the other two sensitive factors. Under the condition that other conditions remain unchanged，the hydrogen production cost of low valley electricity electrolyzed water hydrogen production process is the most sensitive to carbon tax rate，followed by coal hydrogen production and methanol hydrogen production. The carbon tax rate has a very small impact on the hydrogen production cost of natural gas hydrogen production process. Since there is no carbon emission from renewable energy abandoned electricity electrolyzed water hydrogen production，the carbon tax rate has no effect on its hydrogen production cost.

Keywords: hydrogen production from fossil energy；electrolyzed water hydrogen production；carbon tax；sensitivity analysis

StudyonReactionPathwaysofSteam
MethaneReformingforHydrogen
Production
HE Tianzhi，CAI Lei，GUAN Yanwen，
LIU Wenbin

Abstract： A reasonable reforming tube model was established using CFD. The steam methane reforming process was numerically studied under experimental conditions of inlet gas of 614 ℃，2 944 kPa and S/C=2.97 (ratio of steam to carbon). The reaction pathways for H2production were analyzed. The effects of temperature on the reaction pathways for H2production were investigated. The results show that in the process of steam methane reforming，CH4is first cracked into CH3. Then CH3is synthesized into C2H6，and after that H2is mainly generated from the successive dehydrogenation of C2H6；or CH3is converted to CH3OH，and CH3OH is successively dehydrogenated to generate H2. From the perspective of the net reaction rate，the important intermediate species，CH3and CH3OH，are generated first and then consumed along the axis of the tube，so their mole fractions increase first and then decrease along the tube. When the inlet gas temperature increases from 600 ℃ to 1 000 ℃，mole fraction of H2at outlet increases from 44.91% to 50.21%. When the temperature exceeds 900 ℃，the significant reduction in the elementary reaction rate of R60 and R112 retards the dehydrogenation of CH3and its conversion to C2H6. The rate of R100 increases and more CH3is converted to CH3OH. Pathways of C2H6successive dehydrogenation are weakened，and more H2is generated through direct dehydrogenation of CH4and successive dehydrogenation of CH3OH.

Keywords: hydrogen production；methane；steam reforming；elementary reaction；reaction pathways；dehydrogenation

DesignofMonitoringandManagement
PlatformforNaturalGas-fired
CCHPSystem
CAO Yu，LI Fan

Abstract： Taking a distributed energy system of a university laboratory in Jinan as an example，with Niagara Internet of Things technology，the monitoring and management platform for natural gas-fired combined cooling，heating and power (CCHP) system is designed. The monitoring principles and monitoring configuration of the flue gas and water systems are analyzed. The real-time status of monitoring points is displayed on the platform.

Keywords: distributed energy；combined cooling，heating and power (CCHP) system；Niagara Internet of Things technology；monitoring and management platform

GasCombustion，GasAppliances
andGasConsumptionEquipment

InfluencingFactorsofOilTemperature
OverheatingControlDevicefor
DomesticGasCookingAppliances
YAN Wentao，LIU Wenbo，
CHEN Cheng，LIU Boyan，ZHOU Weiye

Abstract： A domestic gas cooking appliance with oil temperature overheating device is used as a test prototype. Referring to the test method of section 6.12 of theDomesticGasCookingAppliances(GB 16410-2007)，6 kinds of different pots are selected as test samples，they are type test pot (aluminum pot)，energy efficiency test pot (aluminum pot with carbon black coating outside)，stainless steel pot，cast iron pot，ceramic pot，stainless steel pot with coating to test the change in inner surface temperature of the pot bottom (namely temperature of pot bottom) and salad oil temperature of different samples. The influence of the depth of the salad oil in the pot，the material of the pot，the thickness of the pot bottom and the thickness of the coating of the outer surface of the pot on the temperature of the salad oil in the pot (namely the operating oil temperature) is analyzed when the oil temperature overheating control device operates. The test equipment，test sample selection and test method are described. The test results show that under the condition of the same pot，if the depth of salad oil is increased，the difference between the temperature of the pot bottom and the temperature of the salad oil is increased，and the temperature of the pot bottom and the operating oil temperature are both decreased when the oil temperature overheating control device operates. When the depth of salad oil is 10 mm，for type test pots，energy efficiency test pots，cast iron pots and ceramic pots，the heat transfer capacity of the pot (namely the heat absorption heat flux) has little effect on the operating oil temperature，which is about 263 ℃. For stainless steel pots and stainless steel pots with coating，the operating oil temperature is significantly different from that of the other four types of pots. The operating oil temperature of the stainless steel pot with coating is as high as 278 ℃，the operating oil temperature of the stainless steel pot is only 255 ℃，and the difference between the two is 23 ℃. It is suggested that the oil temperature fluctuation allowance should be left when setting the action oil temperature of the cooking appliance oil temperature overheating control device，so as to avoid the difference of the pots causing the operating oil temperature of the oil temperature overheating control device to exceed the standard limit value (300 ℃).

Keywords: domestic gas cooking appliance；oil temperature overheating control device；operating oil temperature；inner surface temperature of pot bottom；heating time

InspectionCategoriesandProduct
QualityAnalysisofGas-firedHeating
andHotWaterCombi-boilers
LIU Wenbo，ZHANG Hua，
YANG Lijie，CHEN Jinrui

Abstract： The implementation of domestic and foreign standards for gas-fired heating and hot water combi-boilers，and various inspection categories，including type inspection，energy efficiency inspection，national and local spot inspection，CCC product inspection and energy conservation/environmental protection certification inspection are introduced. Based on the product structure，the product quality problems found in the inspection process of general gas-fired heating and hot water combi-boilers，water-cooled gas-fired heating and hot water combi-boilers，and condensing gas-fired heating and bathing boilers are analyzed.

Keywords: gas-fired heating and hot water combi-boilers；type inspection；energy efficiency inspection；CCC product inspection

GasTransmission，Distribution，
StorageandTransportation

CalculationofTemperatureDifference
forThermalCompensationCalculation
ofGasPipelineinGasCompartment
ofUtilityTunnel
TIAN Huifang，QIAN Dongliang

Abstract： The method of calculating the temperature difference (difference between the installation temperature and the operating temperature of the gas pipeline) for thermal compensation calculation of gas pipeline in gas compartment of unity tunnel is analyzed. The temperature differences in 4 cases of six types of the gas pipeline under the different natural gas flow rates are calculated respectively，including summer installation winter operation，winter installation summer operation，summer installation summer operation and winter installation winter installation. When the nominal diameter of the gas pipeline is the same，the calculated temperature difference decreases with the increase of the natural gas flow rate. When the natural gas flow rate is the same，the calculated temperature difference decreases with the increase of the nominal diameter of the gas pipeline. The calculated temperature difference of gas pipeline is the largest under the condition of summer installation winter operation. In the design of the thermal compensation of gas pipeline，the calculated temperature difference under the condition of summer installation winter operation should be selected.

Keywords: unity tunnel；gas compartment；gas pipeline；thermal compensation；temperature difference calculation

DeterminationofFirePrevention
DistanceofStorageTanksinLPG
StorageandDistributionStation
BasedonRisk
ZHANG Tao

Abstract： From the point of view of the risk that people can bear，taking the LPG storage and distribution station with a total volume more than 5 000 m3and less than 10 000 m3and a single tank volume more than or equal to 1 000 m3as the research object，the principles for determining the fire prevention distance between storage tanks and surrounding structures (residential areas，villages and towns，schools，cinemas and theaters，stadiums and other important public buildings) are discussed. The distance affected by tank accident and the risk assessment are calculated by DNV PHAST software. In the accident impact distance，the accident impact distance of storage tank leakage vapor cloud explosion is the largest，reaching 1 278 m，but it is impossible to take this accident impact distance as the fire prevention distance in practical applications. According to the risk analysis results，in the four directions of east，south，west and north of the storage and distribution station，the risk contribution rate of large rupture of the southern storage tank is the largest. Therefore，the minimum distance (100 m) from the storage tank to the 10-5a-1risk contour line is taken as the fire prevention distance between the storage and distribution station and surrounding structures. On the premise of strengthening the essential safety of equipment and strengthening risk control，the fire prevention distance can also be reduced appropriately.

Keywords: LPG storage and distribution station；fire prevention distance；risk analysis

Coal-to-GasProcessinChina
andCurrentStatusAnalysis
GAO Limin

Abstract： The coal-to-gas process and the current status in China are analyzed. Coal-to-gas has gone through the initial phase from 2013 to 2017，the suspension phase from 2017 to 2018，and the planned advancement phase from 2018 to the present. The impact of coal-to-gas on natural gas demand and supply in China is analyzed，and suggestions on coal-to-gas advance are put forward.

Keywords: coal-to-gas；current status；process；supply；demand

LiquefiedNaturalGas

SiteSelectionofWaterLNGFillingStation
LIU Zhiren，YU Wei

Abstract： The problems in site selection of water LNG filling station are pointed out. The matters needing attention in the site selection (determination of the main functions of water LNG filling station，measurement of the filling capacity，classification，and determination of the layout interval) are put forward. The constraints and basic requirements for the site selection of water LNG filling station are analyzed. Combined with an example，the improvement and application of the site selection method of water LNG filling station are discussed.

Keywords: water LNG filling station；site selection；filling capacity；safety distance

GasSourceandProcessingUtilization

ApplicationofCombustibleGasDischarge
SysteminaGasField
MU Tianlong，WANG Wenping，LU Guangying

Abstract： The function，classification and composition of the combustible gas discharge system are introduced. For the air-assisted combustible gas discharge system，the principles of the components，such as knockout drums，water-sealed drum，flare stack and flare tip are discussed. It is proposed to use a water-sealed drum and injecting purge gas as the measure of the flame retention and the flashback prevention for combustible gas discharge system. A set of air-assisted combustible gas discharge system for a gas field is designed. By the calculation of the thermal radiation intensity of flare tip，it is ensured that the ground heat radiation intensity meets the requirements of the specification under the design conditions. By the hydraulic calculation，it is ensured that the pressure at the inlet of the flammable gas discharge system is less than the set back pressure of the safety valve.

Keywords: combustible gas discharge system；flashback；water seal；velocity sealer；purge system；radiation intensity

GasInformatization

UsingGeographicInformation
SystemtoRealizeIntelligentLaying
ofUrbanGasPipelineNetwork
TAO Yuqi，QIN Yong

Abstract： The principle of using Geographic Information System (GIS) to realize the intelligent laying of urban gas pipeline network is introduced，including front-end data collection and analysis，medium-term system processing，post-space analysis and feedback simulation.

Keywords: urban gas pipeline network；laying；geographic information system；intelligentization

PerceptionandControlofGas
AbnormityofIoTIntelligentGasMeters
SHAO Zehua，QUAN Yaqiang，
LIANG Yongzeng

Abstract： Perception and control technologies of gas abnormity are analyzed (including gas leak safety cut-off technology，flow abnormal safety cut-off technology and pressure abnormal safety cut-off technology). A perception and control system of IoT intelligent gas meter gas anomaly state is proposed. The system consists of object platform，sensor network platform，gas company integrated management platform，service platform and user platform. Each platform has a specific physical entity to achieve different functions. The system has five kinds of processing forms for perception information of the gas abnormity. Different processing forms are used to analyze and judge different perception information to generate control information，which is controlled by the IoT intelligent gas meter. The system has the gas use safety status evaluation function，which can detect the perception function state and control function state of the system，and can also detect the continuous monitoring function state of the flammable gas concentration levels in the environment where the IoT intelligent gas meters are located.

Keywords: IoT intelligent gas meter；perception and control of gas abnormity；gas leak