Experimental investigation on dynamic performance of mode switching in an integrated system under the summer working conditions

Efficient integrated diversified energy supply systems play a pivotal role in addressing current energy challenges. Especially under the summer working conditions, the efficiency is very considerable when the system operates in the refrigeration-hot water mode. However, the fluctuation of system parameters before and after dynamic mode switching exerts substantial influence on the effective integration of system components and stable operation of the system. To achieve a nuanced comprehension of the dynamic characteristics of the integrated system during mode switching, this study utilized experimental method to comprehensively investigate six mode switching processes under summer working conditions. The variation rules of key parameters are explored and the stability of each switching process is compared. The results demonstrate that during the switching from hot water mode to refrigeration-hot water mode (Process E) and from refrigeration-hot water mode back to hot water mode (Process F), the degree of superheat exceeds 0 °C. The degree of superheat maintains stability within the range of 12.4 to 15.2 °C in Process F. The total power fluctuation values in Processes E and F approximate 100 W. Thereinto, Process F exhibits the greatest stability among the six processes, with a maximum stabilized power of approximately 1790 W, an electronic expansion valve opening degree range of 164 to 221, and a peak discharge temperature below 110 °C.