# Special Issue: New Trends in Enhanced, Hybrid and Integrated Geothermal Systems
###### Abstract  
We present a novel and adjustable tri-generation system that is capable of efficient and efficient and efficient and efficient efficient and efficient efficient efficient and efficient efficient efficient and efficient efficient efficient and efficient efficient efficient efficient and efficient efficient efficient efficient efficient efficient and efficient  
destruction rate in the second scenario is calculated as 2980 kW at the expense of an 8.32 percent reduction in the exergy efficiency in the first scenario; and (3) taking into account both the exergy efficiency and total exergy destruction rate in off-design conditions, the best enhancement via the optimization process is achieved on a typical cloudy workday in winter, with 53.21 percent exergy efficiency and a 2570 kW total exergy destruction rate. Comparing the optimization results for both scenarios shows that the system's performance is more improved in the second scenario. [PERSON] et al. [5] experimentally analyzed a smart geothermal heating and cooling heat pump system consisting of an open loop--meaning the use of underground water from an aquifer--by means of a standing column well (SCW) and cross-mixing balancing well heat exchangers. To do so, they modified the present operational technique of two adjacent SCW geothermal heat exchangers, each with a single well. The authors employed this technology in order to improve the coefficient of performance (COP) of the geothermal system, basically through preventing underground water discharge and sustaining a constant temperature in the underground heat exchanger. The two balancing wells were utilized in the cross-mixing methods to restrain the bleed water discharge. According to the authors' findings, the mean amounts of COP measured from the balanced well cross-heat exchange system were, respectively, 3.76 and 3.27 throughout the cooling and heating operations. In other words, they achieved COP enhancements of 23 and 12 percent, respectively, during the cooling and heating operations compared to the present SCW method of the heat exchange system. Moreover, while utilizing a balancing well cross-mixed heat exchange system, the initial underground temperature was kept constant, with only a small standard deviation of 0.08-0.12 \({}^{\circ}\)C over 3-5 days of continuous operation, meaning that a relatively stable heat source supply is possible. [PERSON] et al. [6] numerically investigated the effect of utilizing fins on both the interior and exterior U-tube surfaces of a ground heat exchanger (GHE) under cooling mode, plus axial speed and temperature contours due to the tube curvature for an internally finned U-tube at different speeds. They then compared the results with results obtained from a finless U-tube GHE under the same physical conditions. The authors also simulated both dynamic and static behaviour of simple and finned (both internally and externally) U-tube GHEs to determine the impacts of longitudinal fins on the thermal performance of borehole heat exchangers (BHEs) and the heat transfer rate between circulating fluid and soil around the tubes. The dynamic simulations contained short timescale and frequency response tests. In fact, the authors' goal in performing the dynamic and static simulations was to find the best thermal efficiency. The simulation results illustrate that interior fins enhance the rate of heat transfer more effectively, so that the maximum fluid temperature variation was ~2.9 percent in the tube with exterior fins, and ~11.3 percent in the tube with interior fins, instead of the simple tube. Additionally, increasing the inlet fluid speed can make the differences more substantial in temperature profiles and changes, so changing the inlet fluid speed in the range of 0.02-0.06 m/s enhances the fluid temperature variation in the internally finned U-tube by 5-11.3 percent, in comparison with the finless U-tube. In contrast, the fluid temperature variation is only increased by 0.5-2.9 percent when the external fins are utilized.