Research And Design Of Ground Source Heat Pump Air Conditioning Control System Based On PMV

With the development of economy and society,central air conditioning system has become an indispensable part of people’s daily work and life.As a kind of central air conditioning system,ground source heat pump air conditioning system converts low-grade heat energy（such as groundwater,surface water,surface soil,etc.）into high-grade heat energy by using a small amount of high-grade energy（such as electric energy）,so that the operation efficiency of the system is much higher than that of the traditional central air conditioning system,and the cop index of the equipment can reach more than 4.0.Moreover,due to the use of shallow geothermal energy,the equipment will not cause too much pollution to the environment during operation,which is accepted by more and more users.On the other hand,with the improvement of living standards and quality of life,people have higher and higher requirements for the comfort of living environment.While emphasizing the energy conservation and emission reduction of air conditioning system,how to take into account the regulation of living environment comfort is also particularly important.Therefore,it is of great significance to the design of ground source heat pump air conditioning control system and the research and application of thermal comfort theory.Based on the above purpose,the following research is carried out on the ground source heat pump air conditioning system:First,on the basis of the existing ground source heat pump air-conditioning system,VAV control is studied on the end user side.In this thesis,the fuzzy PID control algorithm is adopted to adjust the output Kp,Ki and Kd control parameters according to the fuzzy rules through the difference of input parameters and the change rate of difference,and then control the speed of the end fan,adjust the air output of the air conditioning system,and control the state of the indoor environment.Variable air volume control based on fuzzy PID control can make the control process more efficient and stable,and effectively reduce the energy consumption of the system.According to the analysis of experimental results,the stabilization time of the system is reduced by 35.7%,the overshoot is reduced by 63.6%,and the system has stronger antiinterference ability.Secondly,the theory of human thermal comfort is introduced to optimize the VAV control effect of ground source heat pump air conditioning system.The traditional VAV control is to adjust the air supply volume of the air conditioning system and adjust the indoor environmental state according to the change of ambient temperature.Compared with the regulation of temperature difference regulation,which is a single environmental parameter,PMV thermal comfort integrates six factors affecting human thermal feeling,so that the VAV regulation of air conditioning system can meet the thermal comfort needs of human body while responding to the change of indoor load.At the same time,according to the external meteorological conditions of the actual environment and based on the thermal comfort equation,the solution process of variables such as clothing outer surface temperature and surface heat transfer coefficient is simplified to verify the simplification effect of the equation.Finally,based on the ground source heat pump air conditioning system in a residential district in Jinan,this thesis designs the variable air volume control based on PMV value.Based on the existing ground source heat pump air conditioning control system,the control strategy is optimized accordingly.By comparing the actual operation data of the system before and after optimization,the performance and energy-saving optimization effect of the air conditioning system under the variable air volume control strategy based on PMV value are verified.Through the analysis and comparison of experimental data,the optimized system can effectively meet the thermal comfort needs of human body,and the average energy consumption of the system is reduced by about 19.5%.