Application Of Decoupling Cylinder In Heat-supply Project And Related Numerical Computation

In modern heating systems of our country, under a prevailing condition of uneven heat distribution, heat consumers have big differ from one another between hot and cold. Heat consumers'adjustment of themselves is poor and energy consumption is large. All the factors above affect users'heating quality seriously. How to achieve the thermal balance of heat networks and use the thermal energy efficiently, and how to improve the hydraulic stability of heating network and achieve optimal operation of the heating system, have aroused a wide range of topics.If the hydraulic disorder is serious, we always use the methods of installing mixing pump (mix water and share the pressure) or surface tape heat exchanger (exchange heat and balance pressure). But installing mixing pump requires much more investment and running costs, the costs of installing surface tape heat exchanger and system maintenance is high. The occupied area is larger and economics is very low. To remedy the problems which appear in the operation of heating network at present, this thesis will introduce a new type of equipment-decoupling cylinder for balancing pressure and flow. We will specify introduce the structure, and working principle of the decoupling cylinder, and we will have a comprehensive analysis about the technically feasible and economic rationality when it is applied to the large central heating system. When the heating system is running, the decoupling cylinder can autonomic regulate the traffic of network so that the flow capacity of a heating network and two heating network can be distributed in a sensible way, while maintaining the system'pressure stable, so it is applicable to household metering system of centralized heat-supply.This thesis will be based on the actual situation of Changchun. We will install decoupling cylinder in the heating-system which is a new type of device. We will specify calculations and analysis on its hydraulic regime and thermal performance in the different connection scenarios, and research and analysis on various parameters' changing status of the heating system (hydraulic imbalance and system energy consumption, etc.).To ensure optimal operation of the system, this thesis relies upon two methods to adjust the circulating pump which are based upon simple speed control and cooperative speed control, and to carry out a detailed calculation and analysis of the economy and reliability of the two methods, and finally we will have a optimal operation scheme after comprehensive comparison, to provide a necessary theoretical basis for practical application of decoupling cylinder in large central heating system.