Abstracts and Key Words

HeatSourceandColdSourceAnalysisonDifferenceofDesignSchemesofGeothermalWaterCoupledHeatPumpHeatingSystem
LU Yan，LIN Hui，TIAN Yuchen，TIAN Liang，ZHU Qiaoyan

Abstract：The process flow and operation strategy of the design schemes of the geothermal water coupled heat pump heating system (based on the principle of cascade utilization of geothermal water heat，the heating system adopts geothermal water direct heating and heat pump unit utilizing waste heat of geothermal tail water) are introduced. The calculation model of system energy efficiency in heating period is established. Combined with the calculation example，the system energy efficiency of two geothermal water coupled heat pump heating systems during the heating period is calculated under the operation mode of centralized regulation with flow varied by steps. Scheme 1: The heating equipment (geothermal water heat exchanger and heat pump unit) and the heating circulation pump adopt a fixed arrangement of one machine and one pump. Scheme 2: centralized parallel arrangement of heating circulation pumps. For the scheme 1，the corresponding relationship between the heating circulation pump and the heating equipment is fixed，and the corresponding heating circulation pump must be activated when a certain heating equipment is activated. Compared with the scheme 1，because the heating circulation pumps of the scheme 2 are centrally arranged in parallel，the corresponding relationship between the heating circulation pump and the heating equipment is relatively loose，and the matching is more flexible. The system energy efficiencies of the schemes 1 and 2 during the heating period are 9.20 and 10.03，respectively. Compared with the scheme 1，the system energy efficiency ratio of the scheme 2 during the heating period is increased by 9%.

Keywords: geothermal water heating; heat pump heating; heating circulation pump; system energy efficiency during heating period

HeatingNetwork，Cooling-supplyNetworkandHeatingStation

ResearchandApplicationofIntelligentBalanceControlSystemofSecondaryHeatingNetwork
LUO Jing，ZHANG Huiyan，ZHAO Yongtai

Abstract：The realization goal，system architecture，control loop and software function of the intelligent balance control system of secondary heating network are introduced. Combined with the engineering example，the effect of the transformation is analyzed. After the transformation，the heat consumption per unit heating area，the electricity consumption per unit heating area，and the water consumption during the heating period all dropped significantly. The indoor temperature of each representative room reached the standard，and the unevenness of heating and cooling was significantly improved. The transformation effect is obvious.

Keywords: intelligent balance control; secondary heating network; application effect

DesignKeyPointsofSteamPipelinesinLargeChemicalIndustryParks
WANG Yingxia，HUANG Xudong

Abstract：Combined with project examples，the design key points of steam pipelines in large chemical industry parks are discussed. The laying method is a combination of overhead laying (bracket laying and truss laying) and pipe trench laying. Temperature and pressure detection instruments are installed at key nodes. Solar and wind energy batteries are used for power supply to realize wireless signal transmission. An optical fiber temperature-sensing system is installed in the pipe trench laying section to monitor the temperature in the pipe trench in real time，and give an alarm when abnormal conditions are found. The design key points of steam pipe diameter and wall thickness，insulation layer structure，compensation method and support spacing are discussed.

Keywords: chemical industry park; steam pipeline; design key points

TreatmentofSpecialNodesinLarge-diameterLong-distanceHeatingNetworkandDesignofInsulatedPipeline
CUI Yan，WANG Lei，LIU Lei，NIE Ke，LI Mingqiang

Abstract：Combined with a long-distance heating network project，the treatment of special nodes in the long-distance heating network and the design of insulated pipeline are discussed. Special nodes include crossing urban roads，railways and rivers nodes. The design of insulated pipeline mainly involves the selection of working pipe steel and wall thickness，and the selection of outer protective layer and thermal insulation layer manufacturing technology.

Keywords: long-distance heating network; crossing; working pipe; outer protective layer; thermal insulation structure

EconomicAnalysisofMagneticSuspensionHeatPumpUnitUsedforCentralHeating
YAN Xiaowei

Abstract：The structure of magnetic suspension compressor，the key equipment，of magnetic suspension heat pump unit is introduced. Combined with engineering example，the supply and return water temperature of the primary heating network of the heating station using the magnetic suspension heat pump unit (using the primary heating network return water from the primary side outlet of the plate heat exchanger as the low-temperature heat source) and the heating performance coefficient of the magnetic suspension heat pump unit are measured and analyzed. The economics of screw heat pump unit and magnetic suspension heat pump unit is compared. Compared with the traditional heating mode using only plate heat exchangers，the heating mode using magnetic suspension heat pump units can effectively reduce the return water temperature of the primary heating network. The daily average heating performance coefficient of the magnetic suspension heat pump unit is relatively high，and the energy efficiency ratio in the heating season can reach 8.93. The power consumption of screw heat pump unit and magnetic suspension heat pump unit during heating period is 39.36×104and 22.48×104kW·h respectively. The electricity price is calculated as 0.9 yuan/(kW·h)，and the electricity cost of the magnetic suspension heat pump unit can save 15.19×104yuan during the heating period. The purchase cost of the screw heat pump unit and the magnetic suspension heat pump unit are 65×104and 120×104yuan respectively. The extra purchase cost of the magnetic suspension heat pump unit can be recovered in 3.62 years.

Keywords: magnetic suspension compressor; magnetic suspension heat pump; central heating; economic analysis

ImprovementandApplicationofJointCoatingTechnologyforDirectlyBuriedHotWaterInsulationPipeline
QIU Hang，LI Peng，XU Wenna，DONG Zhengwei，WEI Jichun，PAN Feng

Abstract：The problems existing in the conventional technology for directly buried hot water insulation pipeline joint coating are analyzed. The joint coating structure，construction technology and advantages of the improved technology are discussed，and the actual application effect is analyzed. The improved process changes the segmented heat shrinkable tape seal in the conventional process to a heat shrinkable sleeve (non-split type) seal，which eliminates the cracking problem easily caused by the thermal elongation of the working steel tube at the bonding place between the heat shrinkable tape and the PE outer protective tube. The polyurethane injection port and exhaust hole exposed to the soil environment in the conventional process are wrapped in the heat shrinkable sleeve，which eliminated the water seepage problem. The bonding place between the heat shrinkable sleeve and the PE outer protective tube is reinforced and sealed by PET packing tape and stainless steel wire. It has strong acid and alkali resistance and can withstand the erosion of groundwater to ensure the sealing effect. It has been applied to directly buried hot water insulation pipeline completely immersed in river water. No leakage has occurred at the joint coating since 2011.

Keywords: directly buried hot water insulation pipe; joint; joint coating; construction technology

BuildingHeating，AirConditioning，VentilationandThermalEnvironment

OptimizationofAirDistributionUniformityofDisc-ventilatedKojiMakingEquipment
WANG Yikang，WANG Feifei，XU Xinhua

Abstract：Aiming at the problem of uneven air distribution in the disc-ventilated koji making equipment of a soy sauce factory in the South，the testing and numerical simulation methods are adopted to discuss the air distribution optimization measures. Test results before transformation: The maximum wind speed of the lower air chamber is different from the minimum wind speed，and the unevenness coefficient is close to or even more than 1，indicating that the air distribution in the lower air chamber is obviously uneven. The difference between the maximum wind speed and the minimum wind speed of the upper air chamber is small，the unevenness coefficient is also relatively small，and there is still a certain degree of unevenness. The simulation results before the transformation: the air distribution in the lower air chamber is obviously uneven. On the test section of 0.9 m，the air forms an obvious high-speed zone behind the air inlet and extends to the wall of the wind chamber，resulting in a relatively high wind speed on the inner wall of the wind chamber. On the test section of 2.5 m，affected by the air intake，the maximum flow velocity appears in the upper part of the high-speed zone behind the air inlet，and the wind speed on the inner wall of the wind chamber away from the air inlet is relatively high. The transformation measures: Measure 1: widening the air outlet. Measure 2: increasing the diameter of the center column of the lower air chamber. Measure 3: adding deflector at the air inlet. Measure 4: on the basis of adding deflector at the air inlet，increasing the diameter of the center column of the lower air chamber. Measure 5: adding perforated plate cover to the air inlet. Compared with before the transformation，the effect of the measures 1 to 3 on improving the uniformity of air distribution is not obvious. There is still an obvious high-speed zone behind the air inlet，and it extends to the wall of the wind chamber，resulting in higher wind speed near the wall of the wind chamber. Although there is still an obvious high-speed flow behind the air inlet of the measure 4，the extension length is shortened，and the high-speed zone near the wall of the wind chamber is also effectively relieved. Compared with before the transformation and the measures 1 to 4，after taking the measure 5，there is no obvious high-speed zone behind the air inlet，and the uniformity of the air distribution of the test section is significantly improved. Among the five measures，the measure 5 has the most obvious improvement effect on the air distribution of the test section of 2.5 m. The measure 5 has the best improvement effect on the air distribution of the disc-ventilated koji making equipment. Among the aperture ratios of the studied orifice plates (55%，35% and 18%)，the best aperture ratio is 35%. The test results after transformation: compared with before transformation，the wind speed distribution on each test section is more even. The unevenness coefficient of each test section is decreased，indicating that the measure 5 is effective to improve the uneven air distribution in the disc-ventilated koji making equipment.

Keywords: disc-ventilated koji making equipment; air distribution; uniformity

CalculationMethodofHeatConsumptionIndexforResidentialBuildingsinHeilongjiangProvince
MA Yifei,WANG Zhaojun,FANG Xiumu

Abstract：Using the dynamic simulation method (the simulation software is DeST-h) and the steady-state calculation method，taking a multi-storey residential building as the research object，the building heat consumption index under the fourth step energy saving standard of 18 typical cities in Heilongjiang Province is respectively calculated. There is little difference between the building heat consumption index obtained by the steady-state calculation method and that obtained by the dynamic simulation method，and the average relative error is -1.67%. The city with the biggest difference is Shangzhi，with a difference of 1.7 W/m2. The city with the smallest difference is Nenjiang，and the calculation results of the two methods are consistent. For Heilongjiang Province,it is feasible to use steady-state calculation method to calculate building heat consumption index.

Keywords: residential building; heat consumption index; dynamic simulation; steady-state calculation

DesignofFloorRadiantHeatingSystemforPrefabricatedBuilding
HAO Qi，MA Kunru

Abstract：The advantages and related policies of prefabricated building are introduced. The importance of controlling the separation ratio of pipelines in the floor radiant heating system to improve the assembly rate is analyzed. Due to the large length of the buried coil in the traditional ground radiant heating system，the pipeline separation ratio is too low. It is proposed to adopt non-wet construction floor radiant heating system (overhead floor radiant heating system and pre-groove floor radiant heating system) to solve this problem. The structure，cost and characteristics of two dry construction ground radiation heating system are introduced. Using wood floors and ceramic tiles as decorative layers，the bulk test of the pre-groove floor radiant heating system was conducted. When the radiation area is fixed，the heating capacity of the pre-grooved floor radiant heating system with ceramic tiles as the decorative layer is strong. The design points of HVAC professional in prefabricated buildings are analyzed.

Keywords: prefabricated building; pipeline separation ratio; non-wet construction floor radiation heating system; design point

GasTransmission，Distribution，StorageandTransportation

Mufti-perspectiveAnalysisonReliabilityofUrbanGasTransmissionandDistributionNetwork
LI Jun，YU Jianjun，YAN Mingqing，MA Hongjing，QIN Chaokui，CHENG Guoliang

Abstract：Taking the reliability as the starting point，the urban gas transmission and distribution network is analyzed from multiple perspectives，and the differences and relations of related issues such as the reliability of pipeline structure，the reliability of network connection，the hydraulic working conditions of the network and the reliability of gas supply are expounded. It is clear that the reliability analysis from different angles is carried out in different ways，and should be focused on different types of lifeline engineering systems and research purposes. The reliability of pipeline structure and the connection reliability are to analyze the network system and its constituent units from the mechanical point of view，and focus on investigating the probability that each part of the pipe network and the pipe network system have structural integrity under certain conditions，without considering the influence of hydraulic condition. The hydraulic working condition analysis of the network is to analyze the overall working conditions of pressure and flow of each node of the network from the perspective of fluid mechanics. The emphasis is on the extent to which the network can still meet the gas demand of various users under the condition of individual pipeline failure，and the influence of structural failure probability is not considered in the hydraulic working condition analysis. The gas supply reliability of the pipe network is a comprehensive evaluation standard adopted on the basis of considering the structural reliability and hydraulic working conditions. It is a probabilistic comprehensive evaluation of the overall gas supply capacity of the pipe network. According to the results of this evaluation，it can be guided to improve the design or improve the built system from the two aspects of pipeline structure and hydraulic working conditions，so as to better promote the gas supply function of the pipeline network.

Keywords: gas network; structure reliability; connection reliability; hydraulic working conditions; gas supply reliability

StudyonPerformanceChangeofPipelineGasAutomaticShut-offValvebeforeandafterUse
WANG Fan，CHAI Jiafeng，CHEN Tingting，XU Xin

Abstract：Combined with the application of pipeline gas automatic shut-off valve in Beijing，taking the automatic shut-off valve used for 5 years as the sample，the test scheme is formulated according to the product standard，the performance of the sample is tested，and the reasons are analyzed. The research results show that by tracking the use of 5 years，the safety function of the automatic shut-off valve product is in line with the expectation，especially the overflowing automatic shut-off and under-pressure automatic shut-off functions have been verified in practical applications. When the automatic shut-off valve is used for 5 years，the internal and external tightness of the product can meet the requirements of the current industry standardAutomaticShut-offValveforPipelineGas(CJ/T 447-2014). There is no obvious change in the overflowing automatic shut-off performance，and the automatic shut-off valve can protect the hose from falling off and breaking resulting in the rapid leakage of gas. The average change rate of the over-pressure automatic shut-off pressure is not large，but the dispersion increases，and the over-pressure automatic shut-off performance reduces，which increases the risk of false shut-off. The average change rate of the under-pressure automatic shut-off pressure has a large negative deviation，and the dispersion is also larger after use，so the under-pressure automatic shut-off performance reduces，which increases the probability of flash back of gas cooking appliance. The electrochemical corrosion，oil smoke and dust in the kitchen environment have little effect on the performance of the automatic shut-off valve，the size and structure of the main parts of the automatic shut-off valve have no obvious change，and the performance of the magnet has no obvious decline. The decrease of the resilience of diaphragm of a sample driving element is the main factor of the decrease of automatic shut-off performance. It is suggested that the diaphragm material of automatic shut-off valve should be improved to improve the resilience of diaphragm. The fault deformation of the diaphragm caused by the lifting rod exceeding the normal stroke in a sample causes the lifting rod to be unable to fall and reset. It is suggested to improve the stroke accuracy of the lifting rod or to improve the reset structure.

Keywords: pipeline gas automatic shut-off valve; performance test; performance comparison experiment; influencing factor

DevelopmentStatusofEarthquakeResistanceandDisasterReductionTechnologyforCityGasSystemsinChina
ZHANG Xiaorui ，SUN Mingye，JING Shuai，QIN Yemei，ZHANG Zengbin，SONG Haixiang

Abstract：The main direction of related research of gas systems earthquake resistance and relevant standards and codes，and development status of gas pipeline earthquake resistance measures，gas pipeline seismic emergency disposal system and gas pipeline seismic cut-off device are introduced. The seismic design of gas pipeline mainly refers toCodeforSeismicDesignofOutdoorWaterSupply，Sewerage，GasandHeatingEngineering(GB 50032-2003) andCodeforSeismicDesignofMechanicalandElectricalEquipment(GB 50981-2014)，and the related research focuses on the seismic design of gas pipelines and the improvement of seismic capacity of pipelines. Learn from the earthquake resistant and disaster reduction experience of gas networks in countries with frequent earthquakes such as Japan and the United States，as an important part of the gas system's earthquake prevention and disaster reduction，the earthquake emergency response system has received extensive attention in China. The main difficulty is to determine the earthquake emergency cut-off threshold. The research of earthquake emergency cut-off device is relatively mature. There are many kinds of emergency cut-off devices，such as falling ball type，permanent-magnet type and electric control type，and the corresponding research and development results have been applied. The related research work of earthquake resistance and disaster reduction of gas pipelines in China lacks engineering connection and demonstration，and corresponding system construction lacks standard guidance，resulting in the lack of practical feedback and correction of corresponding research results，which should be emphasized in the next research.

Keywords: city gas system; earthquake resistance; earthquake emergency cut-off device; earthquake emergency cut-off threshold

LiquefiedNaturalGas

DesignofLNGTankContainerTurnoverYard
YAN Meng，HAN Zhigang，LI Yanyan，LIU Jianhai

Abstract：The national industrial support policies and design standards and specifications involved in the LNG tank container turnover yard are analyzed. Taking a LNG tank container turnover yard project in South China as an example，the determination of fire prevention distance，site layout and supporting facilities are designed. It is believed that the LNG tank container turnover yard project is supported by national policies，and the design specifications are mature. After the completion of the project，it is conducive to the smooth and safe operation of the logistics links such as the relay temporary storage of LNG tank container during the long-distance transportation process and the rapid temporary storage and turnover of the whole ship's imported tank container. However，there are some problems，such as major fire prevention distances of the thermal radiation insulation distance of the tank container yard calculated according to GB 50183-2004，and LNG vapor cloud diffusion isolation distance calculated according to the method of AQ/T 3046-2013 are too large and the project site selection is difficult and so on，so it is suggested to further optimize the calculation method.

Keywords: LNG tank container; turnover yard; fire prevention distance

GasVehicle，ShipandGasFuelingStation

ResearchonClassificationPrincipleofHydrogenFuellingStation
LIU Jianhu，LI Gongzhou，ZHENG Jinyang， LIU Yutao，HE Guangli，ZHOU Xiangrong， LI Leizuo，CHEN Linxin

Abstract：The construction status of domestic hydrogen fuelling stations by the end of September 2020 and the annual distribution of completed hydrogen fuelling stations are introduced. It is pointed out thatTechnicalCodeforHydrogenFuellingStation(GB 50516-2010) has some defects in the classification principle of automobile gasoline and hydrogen fuelling station and automobile hydrogen and CNG fuelling station. In the process of partial revision ofTechnicalCodeforHydrogenFuellingStation(GB 50516-2010)，the classification principle of hydrogen fuelling stations is studied. Energy storage capacity and TNT equivalent are introduced as quantitative indexes to determine more scientific and reasonable classification principle of hydrogen fuelling station.

Keywords: hydrogen fuelling station; classification; discrimination index; energy storage capacity; TNT equivalent

BuildingGasSupply

ResearchonKeyTechnologyofFireSpecialEffectTheaterBasedonSafetyRiskControl
GAO Chunmei，ZHU Yuzhou，HOU Cuicui

Abstract：Based on the characteristics of fire special effect theater，the possible leakage modes (small hole leakage and pipeline fracture leakage) of gas pipeline in the theater and the consequences are analyzed. The process flow and key process parameters of the fire special effect system are described，and the possible gas leakage in the theater is analyzed. The research results show that the possible gas leakage in the fire special effect theater is mainly related to the pipeline design pressure，the inner diameter of the pipeline and the leakage time. The small hole leakage in the preparatory stage of the performance is the most risky leakage mode under the non-catastrophic accident state of this type of theater. The maximum gas leakage is not directly related to the number of regional pipelines，the amount of gas used in the design of special effect burners，and the area of the theater.

Keywords: fire special effect theater; safety risk; key technology

GasEquipmentandMaterials

In-positionDetectionTechnologyofElectromechanicalValveforIoTIntelligentGasMeter
SHAO Zehua

Abstract：The in-position detection device of electromechanical valve (namely shut-off valve) for gas meter usually adopts contact switch，which has problems such as easy oxidation of contact，poor reliability and short life. The in-position detection technology of the electromechanical valve for IoT intelligent gas meter is proposed. The non-contact sensor and photoelectric principle are used to realize the in-position detection of the on-off valve for the IoT intelligent gas meter. The principle，circuit and working flow of in-position detection device are discussed.

Keywords: IoT intelligent gas meter; electromechanical valve; shut-off valve; in-position detection

ApplicationofHardwareSecurityEncryptioninIntelligentGasMeter
WANG Binbin，LU Conghang， DI Peng，HU Mang，ZHU Weiyong

Abstract：The application system architecture of intelligent gas meter based on hardware security control module is introduced. The data sending and receiving process，core module and system are analyzed. The data sending and receiving process involves data uploading and sending. The core module and system include hardware security control module，encryption machine and key management system.

Keywords: intelligent gas meter; hardware encryption; information security

GasEnterpriseManagement

RiskEvaluationofUrbanGasPipelineGridbyAnalyticHierarchyProcess
JIAO Jianying，WU Bo， GU Xiankai，ZHU Yan，DU Jiusong

Abstract：The four steps of AHP modeling to determine the weight are introduced. The gas pipeline is meshed by grid technology，and the grid risk assessment system of gas pipeline is established. The weights of the indicators in the assessment system are determined by AHP，and finally the grid risk assessment is carried out for all grids. All grids are ranked according to the calculated risk value，and the graphs of grid risk value and grid risk ranking are obtained，and the inflection point of the grid ranking where the curve changes sharply to smooth is found. The grid with risk value larger than the risk value corresponding to the inflection point is a high risk grid，which should be paid more attention to in daily inspection and management.

Keywords: urban gas pipeline; gridding; AHP; risk assessment

ApplicationofInternalDetectionTechnologyinUrbanGasPipeline
LIU Chuanqing

Abstract：The internal detection practices of urban gas pipeline are summarized，and the data of multiple rounds of internal detection are analyzed. The difficulties of internal detection are analyzed，and countermeasures and suggestions are put forward.

Keywords: urban gas pipeline; internal detection; deformation detection; magnetic flux leakage detection

OverseasGas

AmericanCityGasPipelineIntegrityManagementSystemandEffectiveness
GUO Baoling,QIAO Jia,DONG Jiuzhang, MA Xuqing,ZHANG Xuejiao

Abstract：The integrity management system of city gas pipelines in the United States is studied (including integrity management regulations and guidelines, integrity management organization and responsibilities, as well as inspection manuals to support the implementation of integrity management, excavation call center and information software), and the effectiveness of integrity management is analyzed. The effectiveness of integrity management is as follows: the application of PE pipe is increasing, the leakage rate is obviously decreased, and the excavation damage rate is decreased.

Keywords: city gas pipeline; integrity management; system; effectiveness