Study On Waste Heat Recovery Of Oilfield Joint Station Based On High Temperature Sewage Source Heat Pump System

Through the survey of the joint station,oil temperature,raw oil flow and dehydration temperature are measured,and the heating load of the joint station is calculated.The present situation of energy utilizing is analyzed in joint station,a large amount of oily water at 30?40? is produced in dehydration process,this part water drainage caused a lot of energy waste.At the same time,the joint station heating furnace is inefficient and the energy utilization is insufficient,which leads to the great waste of energy.In addition,the heating furnace system directly burns fossil energy and emits a lot of harmful gases,resulting in serious environmental pollution.In view of the current situation,this paper puts forward to use high temperature sewage source heat pump system to replace heating furnace system heating raw oil dehydration.Through the analysis of the measured data,it is shown that the conventional heat pump can hardly meet the requirements of the dehydration temperature of the raw oil.So the high temperature heat pump is required.The mathematical models of different high temperature heat pump circulation ways are established in this article.Thermal performance of different circulation ways are analyzed via programming.When the circulation temperature rise is less than 45?,single stage compression heat pump system can be used.When cyclic temperature rise is greater than 45?,two stage compression heat pump system can be used.Through entransy dissipation analysis of load side heat transfer process,load side should use three heat pumps series heating mode and can realize energy ladder utilization.Through the analysis of source side heat transfer process,the source side adopts the way of three heat pumps parallel method to extract heat.Then the process of high temperature sewage source heat pump system is determined,the influence factors of the system are cleared.When meet the requirements of oil-water mixture dehydration temperature,reducing raw oil temperature rise ?ty and oil outlet end of raw material of oil-water heat exchanger is poor ?tg,appropriately increasing high temperature circulating water temperature rise ?tc,at the same time reducing oily water temperature drops ?tw and the outlet end of oily sewage in sewage heat exchanger is poor ?td,increasing cold circulating water temperature drops ?te can obtain good economic benefit.The reasonable values of load side and source side are given.Compared wth primary heating furnace system,the heat pump system has certain energy saving potential.The simulation model of the high temperature sewage source heat pump system is set up used TRNSYS.The results show that the system can achieve the dehydration temperature of the raw oil and meet the raw oil dehydration heat load.Thermal energy loss of full load running is greater 658?681 kW and 1065?1102 kW than those of 83%and 72%heat load running,and electric consumption is greater 150-167kW and 246-274kW.Therefore,the high temperature sewage source heat pump system should have the frequency conversion function.The COPj and COPx are respectively between 4.01?4.32 and 3.35?3.59,which has a large energy saving advantage compared with the original heating furnace system.Energy saving,economy and environmental protection of high temperature sewage source heat pump system are analyzed.Compared with the original heating furnace system,the heat pump system can save standard coal 786t yearly.System static investment payback period is 3.0 years,dynamic investment recovery period is 3.74 years,the net present value is 13.027 million yuan,it has good energy saving and efficiency.When power of the system is provided by coal-fired power plants,the CO2 emission reduction is 215.6 tons per year,and 11 tons of SO2 and 21 tons of NOx are emitted.If it is provided by a gas power plant,3,430 tons of CO2,19.6 tons of SO2 and 6.3 tons of NOx are reduced annually.With the increasing proportion of clean energy generation system,the advantage of the system in environmental protection will become more prominent.The difficulty of low grade waste heat recovery in oilfield system can be solved by high temperature heat pump system.With the oilfield development gradually entered the later period,low temperature waste heat will be more and more,and the high temperature heat pump system application prospect will be more widely.