The Simulated Study Of Water Hammer And Release Press By By-Pass Pipe In Heat Supply Pipe Network

With the development of economic and improvement of the people in our country, the city centralized heating system has substituted the distributed heating stoves. Water hammer in heating system is one the critical problems in development of centralized heating system. When this phenomenon occurs, it can result in great loss of wealth and even endanger safe of persons. The structure of heating system has become more and more complex, and the rate to occur water hammer and the harm of water hammer are improved greatly. Because water hammer greatly menaces safety of system, developing the equipment to prevent water hammer and establishing reasonable strategy for heating network system are more and more necessary and became an important technical task.In this paper, the concept of water hammer in heating network and its harm are expatiated. Basic hydro-equipments for transition process, namely movement equipment and continuity equipment, are introduced; characteristic line equipment is detruded and finite difference equipments are gained. Characteristic line method has many advantages, such as clear concept, high calculation precision, good stability and easy to write program, and is greatly used in engineering. The mathematic model for usual heating system is built with boundary condition in this paper and calculation for water hammer in heating system without side connected line is done using characteristic line method. The influence of system flux on water hammer is also analyzed. The pressure discharge ability for the heating system with circle water pump parallel connected side connecting line with different diameter has been calculated and compared. Resalable diameter for side connecting line is defined to ensure system safety, mainly for radiator safety at heat users, when the pump is off.