The Research On Automatic Heating System

The main problems of Chinese heating system cover three aspects by comparing the current development and relative polices for heating domestic and abroad. The problems lie in the unreasonable way of charge, Lack of regulation control and lower efficiency of utilization and heavy waste. The paper is based on the design of heating-meter, consistent pressure and the data collection system founded on the Ethernet, trying to find solutions to the three problems.Intelligent heating measurement based on MCS-8051 and temperature control system is designed under the heat measuring principle. Temperature measuring is realized in the form of single-chip by employing digital DS18B20 sensor. The way to measure the flow is to connect single chip with ultrasonic flow detector which is based on frequency difference method. The temperature moderating is conducted by controlling the opening extent of regulator after comparing room temperature with the setting one, in order to meet user's need for heating. As a result of water unbalance caused by change of heat pressure in and outside as well as the self moderation of user, the paper designs constant pressure water supply system of variable frequency pump was designed, in which three pumps were driven by an inverter. the Lock frequency and phase lock synchronous switching circuit was designed based on CD4046 in this paper.At the same time, photoelectric coupling switch is designed to meet the need of main chip's switch between power supply and frequency,which controls the opening or closing of the pump according to the water pressure. Because constant pressure water supply is a nonlinear, higher order, delayed system, it is necessary to adopt the fuzzy PID control algorithm combining the classical PID management with advanced professional system, to realize the best control of the system.Considering the safety reliability and economy of operation, this paper designs two levels control chips, including the main MC9S12NE64 and the subsidiary MCS-8051. The two chips adopt asynchronous way of communication by interface conversion circuit RS232-RS485. The MC9S12NE64 charges the heating fees by connecting the Ethernet with management center. Meanwhile, in order to support the operation and monitoring of the chips, this paper designs the peripheral circuit, including circuit design of power, external clocking, watch-dog, a network interface, hydraulic detection and synchronous LCD display.