Heating Characteristic Of Micro Capacity Distributed Energy System Incorporating VM Cycle Heat Pump

The distributed energy system can locally and effectively provide sorts of energy demand.It is one of energy utilization ways,which can reduce building energy consumption,promote the reform of energy consumption of urban and rural,and optimize energy structure.For the micro-distributed energy system,there is a problem that it is difficult to choose heating and cooling equipment.Thus,this paper studied the heating characteristic of micro-distributed energy system based on VM cycle heat pump.The model is verified by concrete examples.In this paper,graph theory is used to establish the micro-distributed energy system with three user & double-heat sources,the system includes hydraulic model of the continuity equation of flow and the loss equations of circulating pressure and so on.In addition,the system also includes thermodynamic model of the energy equation and system resistances.Besides,the model is verified by concrete examples in this paper.Under heating conditions,the operation characteristics of micro-distributed energy system based on VM cycle heat pump were calculated using MATLAB.Results show that the heat loss on node is more than tabulation,and the heat loss is the largest on node 3.The flow deviation value of pipe 1 is relative great,while there is little difference between actual and design value for pipe 4 and 5.When the pipe diameter exceeds 100 mm,the resistance loss of each pipe is almost the same.The value and change of resistance loss for pipe 4 is the largest,while it is the smallest for pipe 2.The actual system operating parameters tend to deviate from the design value,so it needs to be adjusted in the design and operation stages.For the micro-distributed energy system based on VM cycle heat pump,some parameters,such as the flow,pipe diameter,pipe length,the temperature of supply and return water,were regarded as decision variable for the analysis of Pareto efficiency by NSGA-? algorithm.For the object in this paper,when pipe diameter and pipe length were changed,the distribution of individual optimum points became even.The individual optimum points were distributed uneven as the flow was changed.For the temperature of supply and return water,95/70? is the optimum temperature point,but individual optimum points tend to diverging distribution for other temperatures.Therefore,in order to reduce the system heat loss and resistance loss,for the calculation object in this article,the pipe length and pipe diameter may be properly adjusted in the design stage.In the operation phase,try to avoid the quantity adjustment and give priority to the quality adjustment,at this time the recommended temperature of the supply and return water temperature is 95/70?.