Application Research Of In Air Conditioning Cold And Heat Source System Based On PLC

With the progress of science and technology and the development of economy, central air conditioning system has gradually become an indispensable part of modern public and civil buildings. Hot and cold source system is the core part of the air conditioning system, and the level of its operation and management directly influences the safety, reliability and economy of the whole air conditioning system. Air conditioning system needs to consume large amounts of electricity and fuel, and its consumption of electricity accounted for the proportion of the total electricity consumption city rises year by year, which has become the important factor of the too fast power grid load growth. The popularization of air conditioning energy conservation and environmental problems brought by the, has become a concerning issue in the development of economy in our country.These facts have proven that targeted to apply computer control technology and the air conditioning system operation management can improve the operation quality effectively, save energy, improve the management level, reduce the labor intensity, thus obtains the good economic and social benefits.This article is based on the complex-building air conditioning heat and cold source system in Chongqing DaZhuLin as the research model, considering energy saving and efficiency requirements, and this paper is divided into Ground source heat pump and conventional Heat and Cold source system. First of all, we must analyze the fan in the system and must analyze the water pump units operation and control mode, after the acceptance of the project, the quantity of cold and heat supplied by the ground source would be monitored by the energy meter monitoring; the temperature and the flow of chilled water in and out, cooling water in and out supplied by the ground source would be monitored by the flow meter monitoring; the power consumption of the host ground source heat pump, chilled water pump, cooling water pump would be monitored by the electricity meter monitoring, at last, the energy saving would be calculated based on the formula, then design the hardware of the system and program according to the energy conservation plan.This article is about the theory analysis and research on the demand for air conditioning cold and heat source system based on social and economic development, the heat and cold source of the existing air conditioning is complex and has varied functions and the energy saving effect is different, the best type of cooling and heat sources and design scheme should be choused based on the region’s geographical conditions and climate conditions. According to the need of energy saving, the design of efficient frequency conversion centrifugal chiller and heat pump combinations as a regular cold heat source system of cold and heat source equipment, ground source heat pump according to the geographical situation of chongqing soil source is chosen as the air conditioning heat and cold source, detection control exchanger of chilled water in and out of the water temperature of cooling water, circulation water flow and compressor exhaust heat absorption of heat.This paper expounds the selection of cold and heat source device and the design of the ground source heat pump and conventional of cold and heat source. Part of ground source heat pump buried pipe system is as the detection control object, and this system uses the PLC computer control system in Rockwell company AB- PLC programmable controller as the control core of the whole system, compared with other PLC, its function is more powerful, more stable performance. This control system uses Controllogix controller and RSLogix5000, and provide related to building control interface(open communication protocol and dry contact interface) specifically for ground source heat pump units and the supplementary equipment for automatic control, the temperature of the in and out water of buried pipe, soil, indoor and outdoor, system operation would be acquiesced and recorded timely.This article is to choose the best cold and heat source scheme according to the analysis of air conditioning heat and cold sources compared, make it reach the best state of automatic control and operation by monitoring the buried pipe system by PLC, and get the best energy saving design based on the comprehensive analysis and calculation of cold and heat source system equipment.