空气源热泵热水器控制系统的设计

发布时间：2018-10-16 10:23

【摘要】：在环境问题与能源危机日益严重的今天,空气源热泵热水器以其节能、环保的特点在热水器行业受到越来越多认可,从而在近年得到迅速发展。空气源热泵热水器是一种使用热泵技术,将环境空气中蕴藏的低温热量用来制取热水的装置,通过热泵工质的热力循环间接加热制取热水,能够做到水电分离,大幅降低了触电事故。当然,为了能够充分发挥空气源热泵热水器节能、环保、安全的优势是离不开设计合理的热泵控制系统的支持。只有在热泵控制系统的智能调控下,才能保证整个空气源热泵热水器稳定、可靠地运行。本文主要研究空气源热泵热水器的电控系统。首先,本文分析了空气源热泵热水器工作原理,主要包括热泵系统制热过程以及室外蒸发器结霜时的除霜控制流程。阐述了热泵工质的选用要求和目前广泛使用的R22的特性。同时对实验热泵装置的压缩机、冷凝器、蒸发器、风机、热力膨胀阀等主要组成部件在热泵系统中的作用以及三相压缩机变频调速的原理作详细说明。并在此基础上对实验热泵系统中需要控制的对象进行分类总结。考虑成本因素依然是制约空气源热泵热水器普及的主要原因,本文提出了以单片机作为控制芯片,配以三相SPWM波形发生器与智能功率模块相结合的电控系统。其次,分析控制系统工作原理以及实验热泵装置所需要达到基本目标,给出控制系统的硬件原理图SCH设计、PCB设计和程序软件设计。热泵控制系统硬件电路主要包括直流供电电路、SPWM波型发生器电路、智能功率模块电路、水位信号电路、温度采集电路、按键电路和外部中断保护电路等。系统控制程序主要包括温度采集子程序、温度设定子程序、SM2001波形发生器控制子程序、温度PID控制子程序、除霜控制子程序等。同时对实验空气源热泵热水器装置的主要部件,如压缩机、风机、循环水泵的电气接线方式给出说明。最后,本文将所设计的空气源热泵热水器电控系统与实验空气源热泵热水器装置进行整合调试,以验证控制系统的可行性。系统测试中阐述了制热温度系统中运用经验法PID参数整定的一般过程,并对系统水温可能出现振荡的原因进行预判。通过测试验了证本文所设计的控制系统能够保障实验热泵装置稳定运行,达到了预期的设计要求。
[Abstract]:With the increasingly serious environmental problems and energy crisis, air source heat pump water heaters have been more and more recognized in the water heater industry for their energy saving and environmental protection characteristics, which have been developed rapidly in recent years. Air source heat pump water heater is a device that uses heat pump technology to make hot water by using the low temperature heat stored in the ambient air, and indirectly heating the heat pump working fluid to make hot water, which can achieve the separation of water and electricity. Electric shock accidents have been significantly reduced. Of course, in order to give full play to the air source heat pump water heater energy-saving, environmental protection, safety advantage is inseparable from the design of a reasonable heat pump control system support. Only under the intelligent control of the heat pump control system can the whole air source heat pump water heater operate stably and reliably. This paper mainly studies the electric control system of air source heat pump water heater. Firstly, the working principle of air source heat pump water heater is analyzed, which includes heat pump system heating process and defrosting control process when outdoor evaporator frosts. The selection requirements of heat pump working fluids and the characteristics of the widely used R 22 are described. At the same time, the function of compressor, condenser, evaporator, fan and thermal expansion valve of experimental heat pump device in heat pump system and the principle of frequency conversion speed regulation of three-phase compressor are explained in detail. On this basis, the experimental heat pump system need to control the object classification and summary. Considering the cost factor is still the main reason of restricting the popularity of air-source heat pump water heater, this paper proposes an electronic control system which uses single-chip microcomputer as control chip and combines three-phase SPWM waveform generator with intelligent power module. Secondly, the working principle of the control system and the basic goal of the experimental heat pump device are analyzed. The hardware schematic diagram SCH design, PCB design and program software design of the control system are given. The hardware circuit of heat pump control system mainly includes DC power supply circuit, SPWM wave generator circuit, intelligent power module circuit, water level signal circuit, temperature acquisition circuit, key circuit and external interrupt protection circuit. The system control program mainly includes temperature acquisition subroutine, temperature setting subroutine, SM2001 waveform generator control subroutine, temperature PID control subroutine, defrosting control subroutine and so on. At the same time, the main parts of experimental air source heat pump water heater, such as compressor, fan and circulating water pump, are explained. Finally, the electronic control system of the air source heat pump water heater is integrated with the experimental air source heat pump water heater to verify the feasibility of the control system. In the system test, the general process of PID parameter setting using empirical method in the heating temperature system is expounded, and the reason for the possible oscillation of the water temperature of the system is forecasted. The experimental results show that the control system designed in this paper can ensure the stable operation of the experimental heat pump device and meet the expected design requirements.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU822

【参考文献】