Study On Energy-Saving Operation Strategy Of Ground Coupled Heat Pump Systems In Office Buildings

Nowadays,energy plays a vital role in our society,the world demand for energy increases day by day,people's awareness of environmental protection has become strong increasingly,and rising energy reduction targets year after year,people are increasingly concerned about environmental protection and efficient energy use,energy-efficient air conditioning systems and green building came into being.In this paper,the ground source heat pump technology and direct buried pipe cooling technology directly into the low-grade energy use,energy use is an energy-saving and environmental protection.In this paper,in order to study the effect of building in the long run when using two kinds of different operating strategies,a case of office building in Tianjin was studied.The hourly loads of the office building was simulated by e-QUEST.Then the heat pump system model of the office building was built in TRNSYS.And by comparing the measured and simulated values,the validity of the model has been verified.By conducting two years of tests we found that without opening the heat pump,the heat from ground delivery to the building directly is sufficient to satisfy the needs of the building in the early summer and early autumn.The COP is high,COP can achieve 27.9 in 2015,21.2 in 2014.In midsummer,the outdoor temperature and humidity is high,the heat pump need be opened to satisfied the cooling load of the build,the COP was 3.56 in 2014 and 3.61 in 2015,which is lower than the COP of direct cooling.Though the temperature of the water is a little high when cooling directly,we found the temperature and humidity in rooms can meet the design requirements through field test.Then we simulated the 10 years' operation of the building which under the direct cooling and unit cooling modes.The results show that the soil temperature was 15.5? after 10 years when cooling directly,the soil temperature rise 1.2?,the soil temperature rise is 1.5? when cooling by units,there is a little difference between the two.After 10-years' running,the COP of cooling directly is 23.1,and the COP of conventional cooling is 3.73,the former is 6 times than the latter,and the former can save power 12452 kWh,which equivalent to reduce emissions CO₂9955 kg,SO₂299kg,NOx150 kg.