Research On The Optimal Matching And Scheme Comparison Of Stand-alone Photovoltaic Seawater Source Air Conditioning System

As a renewable energy,solar energy has the advantages of clean,cheap and wide range.Seawater source heat pump uses seawater as a cold and heat source,and only through a small amount of electric energy input to achieve the purpose of building heating or cooling,which is conducive to the efficient utilization of resources and sustainable development.For a large number of remote islands where conventional energy is scarce,the utilization of solar energy and seawater resources can play a vital role in relieving the tense energy situation,reducing conventional energy consumption and promoting building energy conservation.The stand-alone photovoltaic seawater source air conditioning system integrates three technologies of photovoltaic power generation,energy self retaining air conditioning and seawater source heat pump,and can achieve self sufficiency in energy,which is not rely on conventional energy such as power grid,coal-fired,fuel and natural gas.In the case of sufficient daytime light,the energy required for operation of the seawater air conditioning system will directly come from photovoltaic power generation,the surplus generating capacity will be directly stored or drive ice making unit for ice storage to meet the cold load demand of the building in the absence of light in the daytime and at night.So two types of energy storage are proposed in this paper: electricity storage and ice storage.The components of the two forms of the system are introduced,and the working principles and processes of the two systems are analyzed.The mathematical models of the seawater source air conditioning unit,the device of photovoltaic power and electric power storage,the ice storage device are set up respectively.The 500 kW cold load module is used as the benchmark,the optimal matching of the key equipment such as the refrigeration unit,the air conditioning terminal,the device of photovoltaic power and in the two systems are obtained under the setting condition.The operation performance of the two systems is analyzed,and the operational strategy of the electric storage system and the ice storage system on typical day is expounded.The stand-alone photovoltaic seawater source air conditioning systems of two different energy storage methods are compared and analyzed from the following four aspects:energy efficiency ratio,photovoltaic panel area,equipment area and system economy.The results show that in the system energy efficiency ratio,the EER value of the air conditioning system of electric storage is 3.41,which is higher than 1.14 of the air conditioning system of ice storage.In the area of solar photovoltaic panels,the air conditioning system of ice storage is approximately 1.24 times that of the air conditioning system of electric storage.In the equipment area,the air conditioning system of ice storage is approximately 7.8 times that of the air conditioning system of electric storage.In terms of system economy,the investment required for the air conditioning system of ice storage is approximately 22.4% less than that of the air conditioning system of electric storage.So the stand-alone photovoltaic seawater source air conditioning system of electric storage is superior to the stand-alone photovoltaic seawater source air conditioning system of ice storage in the matter of energy efficiency ratio,photovoltaic panel area,equipment area,but the seawater source air conditioning system of ice storage has obvious advantages in the economic system.The conclusion in this paper can be used as a theoretical reference for design and construction of building air conditioning system in the area.