Research On Working Hours Quota Of Valve Construction Under The Balance Of Secondary Network Based On MOD

With the continuous acceleration of urbanization,the area of central heating is growing.The heating balance of heating system composed of heat source,heat exchange station and heat users is often broken due to the change of heating area,heating pipe network and heat load,resulting in the fact that the actual temperature of heating is no longer consistent with the design temperature or the imbalance of cold and heat between the front and back end of heat users.In order to adjust the heat supply balance,the most simple and convenient way is to remove the original self operated valve and install the static balance valve in the secondary heating network system composed of heat exchange station,heat users and the pipeline facilities connecting them,so as to achieve the hydraulic balance and thermal balance of the system.This method is also called the quality regulation method of secondary network balance.In the process of secondary network balancing valve construction,due to many types of valve construction,many types of overall operation environment,and many types of valves,the man hour quota management of valve construction mostly depends on the past construction experience and is generally estimated,which is lack of accuracy,which makes it difficult to accurately formulate the construction plan and cost estimation.Therefore,this paper makes a further study on the man hour estimation of valve construction engineering under the balance of secondary network.The main contents are as follows:(1)According to the specific situation of the valve construction site and the previous construction experience,this paper sorts out the various constituent factors(i.e.various operation types,working conditions,valve types)of the secondary network balance valve construction operation and their mutual relations,and then determines the typical operation,typical working conditions,typical valve types(weight is defined as 1)and the weight of various atypical operation types,working conditions and valve types through the questionnaire survey of the industry experts.Then,according to the relationship between the constituent factors of valve construction,the similarity coefficient of working hours of valve construction is determined;(2)Through the method research,the process flow of typical valve construction operation composed of typical operation,typical working conditions and typical valves is optimized and improved,and the stopwatch time measurement method is used to estimate the standard working hours;(3)According to the standard process of typical valve construction operation,the construction action of typical valve construction operation is optimized and improved through MOD analysis,the standard action sequence is determined,and the standard working hours of typical valve construction operation under MOD are estimated,which are mutually verified with the standard working hours under stopwatch method;(4)According to the similarity coefficient of working hours of valve construction and the standard working hours of typical valve construction,the standard working hours of other atypical valve construction can be estimated according to the proportional relationship,and then the working hours of the whole project can be obtained;(5)This method is used to estimate the working hours of a valve construction project under the balance of a secondary network,which is verified by practice.The research content of this paper provides a method for the man hour quota of valve construction engineering under the secondary network balance,and provides a new idea for the estimation of more valve construction man hour in the future.