地源热泵空调系统自动控制策略研究与实现

发布时间：2018-05-31 15:57

本文选题：地源热泵 + 地埋管换热器　；参考：《东华大学》2013年硕士论文

【摘要】：空调系统的节能是建筑节能中一个迫切需要解决的问题。近年来,地源热泵空调系统以地表浅层地热为热源热汇,对建筑进行供暖和供冷,以其突出的环保和节能特性,得到了广泛的应用。但在系统的实际运行中,由于系统组成复杂,人工调控操作误差较大以及部分工作人员缺乏经验,往往造成系统的运行管理不当,造成很大的资源浪费。并且地源热泵热失衡问题已经成为地源热泵系统正常运行以及广泛使用的主要限制因素。为了解决目前地源热泵空调控制方面存在的问题,本文拟开发一套合理可靠的地源热泵空调系统控制策略及相应的控制软件。首先,对地源热泵空调冷冻水系统的控制方式进行对比研究,得出合理的一次泵变频控制策略。针对地源热泵空调主要部件地埋管系统进行详细的实验和理论分析,研究实际运行中影响系统运行效率的主要因素。研究得出地埋管地埋管出水温度越低,机组效率越高。地埋管管内介质流速存在一个合理范围,上海地区为0.4m/s～0.6m/s。并提出了合理有效的地埋管分区运行变频控制方式。对上海地区常用的冷却塔复合式地源热泵系统辅助侧的控制策略进行研究,通过对比分析得出,在制冷季的初期和末期冷却塔单独运行,中期以地埋管出水温度作为控制参数,地埋管系统和冷却塔系统一起运行的运行策略比较合理。为进一步改善热堆积、提高运行的节能效果,需要对系统的运行进行实时监测,以对下一个运行周期进行预测控制。然后,在此基础上,本课题组搭建了一个地源热泵实验平台。并根据该实验平台的具体情况,设计了一套具体可行的自动控制策略。按照传感器和执行机构为现场元件层、PLC控制器和单回路控制器为控制层、LabVIEW上位机软件为管理层的三层网络控制方案,对整个控制系统硬件和层与层之间的数据交换进行整体设计、调试。其次,根据所确定的合理控制策略和现有实验平台开发了一套可视化程度高、使用方便的地源热泵自动控制软件。该软件能对土壤温度场和系统运行状态进行实时监测；能对系统的运行参数进行设定和实时调控；能对空调系统温度超限、系统故障进行报警提示；并能将系统数据实时显示、储存及打印。最后,对整套控制系统的硬件系统和控制软件进行现场调试和分析,得出该控制系统运行稳定,系统数据的采集、显示、超限报警等都运行正常。该系统能根据地埋管出水温度和室内温度的变化自动调节运行方式,能实现地源热泵的节能变流量运行,方便节能并能在一定程度上消除地埋管系统热不平衡现象。本文研究的合理控制策略和自控软件对完善地源热泵空调系统的运行管理有重要意义。可以提高系统运行效率,降低运行能耗：能够在定程度上改善地埋管系统土壤热堆积问题；有利于空调系统运行管理,能够直观的了解系统运行状况,降低运行管理费用；有利于地源热泵空调在实际工程中进一步推广应用。
[Abstract]:The energy - saving of air - conditioning system is an urgent problem in building energy - saving . In recent years , ground - source heat pump air - conditioning system has been widely used in recent years because of its complex composition , large error of manual regulation and operation and lack of experience . In order to solve the problems existing in the air - conditioning control of ground - source heat pump , a reasonable and reliable control strategy of ground - source heat pump air - conditioning system and corresponding control software are proposed in this paper .

First , the control method of the air - conditioning chilled water system of ground - source heat pump is studied . The main factors that influence the operation efficiency of the system are discussed in detail . The results show that the lower the water outlet temperature of the ground - source heat pump , the higher the efficiency of the unit , the more reasonable the operating strategy of the underground pipe system is 0.4m / s ~ 0.6m / s . The control strategy of the underground pipe system and the cooling tower system is reasonably effective . In order to further improve the heat accumulation and improve the energy - saving effect of operation , the system operation is monitored in real time to forecast the next operation cycle .

Then , on the basis of this , a ground source heat pump experiment platform is built . According to the specific situation of the experimental platform , a specific and feasible automatic control strategy is designed . According to the sensor and executing mechanism as the field component layer , the PLC controller and the single loop controller are the control layer , the upper computer software of LabVIEW is the management layer three - layer network control scheme , and the data exchange between the hardware and the layer and the layer of the whole control system is designed and debugged .

Secondly , the automatic control software of ground source heat pump with high degree of visualization and convenient use is developed based on the reasonable control strategy and the existing experimental platform .
the running parameters of the system can be set and adjusted in real time ;
The system can alarm the temperature of the air - conditioning system and the system failure ;
and can display , store and print the system data in real time .

Finally , on - site debugging and analysis of the hardware system and control software of the whole set of control system are carried out . It is concluded that the operation of the control system is stable , and the system data collection , display and overrun alarm function normally . The system can automatically adjust the operation mode according to the variation of the water outlet temperature and the indoor temperature of the buried pipe , so that the energy - saving and variable - flow operation of the ground source heat pump can be realized , the energy - saving and energy - saving can be realized , and the heat unbalance of the underground pipe system can be eliminated to a certain extent .

The reasonable control strategy and auto - control software studied in this paper have great significance for improving the operation and management of the air - conditioning system of the source heat pump .
The system is favorable for the operation and management of the air conditioning system , and can intuitively know the operating conditions of the system and reduce the running management cost ;
and is beneficial to further popularization and application of the ground source heat pump air conditioner in practical engineering .
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU831

【参考文献】