Research On Embedded Control System Of A Low-temperature Cogeneration Equipment Using Heat Pipe Technology

Currently,the mature power generation equipments used on low-temperature waste heat are difficult to be put into operation because of these obvious defects:high processing costs,maintenance inconvenience,high consumption of running and so on.Based on this,our group has been working on a small Roots-type power machine and has verified its feasibility in tests.However,this device can not achieve a complete process,that is from waste heat recovery to steam generation.Accordingly,this article put forward a new equipment used in low-temperature waste heat recovery and power generation,which is mainly composed of heat pipe exchanger and Roots-type steam power machine.And then its modular-embedded control system was developed on the basis of analysis of its technological process and functional requirements.By adding bus technology applied to the system,the paper not only simplified the hardware structure,it also achieved real-time data acquisition of a plurality of field instruments and precise control of a plurality of proportional valves in complex industrial environments.The paper carried on research from the following four aspects:1.The article analyzed the composition and technological process of the equipment on the whole,proposed its control requirements based on a detailed analysis of the difficulties in its control,and defined the detail information of the controlled objects according to its technological process.2.It finalized the whole hardware scheme in line with its functional requirements and described the circuit diagrams of all the major functional modules in detail,including power supply circuit,the minimum system circuit,signal acquisition circuit for field instrument,control circuit for electric proportional valve,digital I/O interface circuits and external communication interface circuit.In addition,the circuit board was developed and produced.3.Upon completion of the hardware development,The software is divided into modules according to the functional requirements in the direction of modular design concept.Furthermore,the key techniques are analyzed and discussed in detail,485 bus signal acquisition based on Modbus Protocol,digital to analog conversion composed of C8051F040 MCU and DAC7568 based on SPI bus,human-computer interface design and development techniques of the level communication included.This laid a good foundation for software debugging on the whole,which will be based on some kind of operation strategy.4.The main functions of the embedded control system were tested from aspects of its hardware and software.At first,the correctness of basic hardware circuits were tested and determined.Upon that base,485 bus signal acquisition module and converter module for proportional valve control were debugged and verified respectively combined with the existing conditions.The tests above ensured the feasibility of its function on each module,verified the accuracy of the self-developed communication procedures between the microcontroller and touch screen on data processing,and laid a good foundation for the following entire machine commissioning...