【正文】 the condenser fan inlet/outletPower input to the pressorPower input to the brine circulating pump/the condenser fanTotal power input to the whole systemHeat extraction rate from the groundHeating load of the room testedHeat extraction rate per meter of horizontal groundheat exchanger lengthHorizontal ground heat exchanger length in m per kW of heatingHeating coefficient of performance of the heat pump unitand whole systemaSome thermodynamic data were taken from [4,13].C03m3/s15 8C0 8C kW kW kW kW kW/m m/kW–C015/42 8CValue UnitC15Pump:˙Exdest。C138254。1:6078v0222。1:6078v222。P=P0222。240。T=T0222。vCp。 (15)The total flow exergy of air is calculated from [14]:ca188。240。cinC0 cout222。X˙ExinC0X˙Exout188。 ˙mc (18)For exergy destruction (or irreversibility), the entropygeneration˙Sgenis calculated first and used in the followingequation:˙I 188。out188。ToutC0 Tin222。˙Wpumps254。 (8)˙mair188。air240。hi。h1C0 h4222。 ˙mref240。Tout。˙WoutC0˙Winis the rate of work output, and hthe specific enthalpy.Assuming no changes in kiic and potential energies withno heat or work transfers, the energy balance given in Eq. (2)can be simplified to flow enthalpies only:X˙minhin188。in188。X˙minhin188。X˙mout(1)where ˙m is the mass flow rate, and the subscript ‘in’ stands forinlet and ‘out’ for outlet.The general energy balance can be expressed below as thetotalenergyinputequaltototalenergyoutput240。 Ground source heat pump。 Energy。fax: +90 232 388 8562.Email addresses: (O. Ozgener), (A. Hepbasli).03787788/$ – see front matter 2020 Elsevier . All rights reserved.doi:borehole configuration is usually preferred over horizontaltrench systems because less ground areas are required. Thevertical ground heat exchanger consists of a number ofboreholes, each containing a Utube pipe. The depth of theborehole ranges usually between 40 and 150 m, and thediameter – m. The borehole annulus should begrouted with materials that provide thermal contact betweenthe pipe and the surrounding soil/rock and to protectgroundwater from possible contamination. The efficiency ofhouse or building. In the cooling mode, heat is absorbed fromthe conditioned space and transferred to the earth through itsground heat exchanger. GSHPs are an efficient alternative toconventional methods of conditioning homes because theyutilize the ground as an energy source or sink instead of usingthe ambient air. The ground is a thermally more stable heatexchange medium than air, essentially unlimited and alwaysavailable. The GSHPs exchange heat with the ground, andmaintain a high level of performance even in colder climates.The ground heat exchanger used in conjunction with a closedandconnectedtoaheatpumpthroughwhichwater/antifreezeiscirculated. For the groundloop heat exchangers, verticalheat sink in cooling mode operation. In the heating mode, aGSHP absorbs heat from the ground and uses it to heat thesystems consist of a sealed loop of pipe, buried in the groundthe design, simulation and testing of GSHP systems. 2020 Elsevier . All rights reserved.Keywords: Building。 Geothermal energy。 accepted 30 April 2020source heat pump (GSHP) systems for the system analysis anda solar assisted vertical GSHP and horizontal GSHP. The performancesratio, relative irreversibility, productivity lack and exergeticin terms of energetic and exergetic aspects. The values for COPHP66–75O. Ozgener, A. Hepbasli/Energy andNomenclatureC specific heat (kJ/kg K)COP heating coefficient of performance (dimensionless)˙E energy rate (kW)˙Ex exergy rate (kW)f exergetic factor (%)F exergy rate of fuel (kW)h specific enthalpy (kJ/kg)˙I irreversibility (exergy destruction) rate (kW)˙m mass flow rate (kg/s)P pressure (kPa)˙P exergy rate of the product (kW)˙Q heat rejection rate (kW)R ideal gas constant (kJ/kg K)s specific entropy (kJ/kg K)˙S entropy rate (kJ/K)T temperature (K or 8C)˙V volumetric flow rate (m3/s)˙W rate of work or power (kW)Greek lettersd fuel depletion rate (dimensionless)e exergy (second law) efficiency (dimensionless)w humidity (dimensionless)j productivity lack (dimensionless)r density (kg/m3)x relative irreversibility (dimensionless)c specific exergy (kJ/kg)v specific humidity ratio (kgwater/kgair)Indices0 reference (dead) statea, air aircol collectorp pressorcond condenserdest destroyedevap evaporatorfc fancoilgen generationgrh groundheat exchangerHP heat pumpi isentropicin input, inletm mechanicalout outputp constant pressurepump pumpr residentre relativeref refrigerant (R22)s isentropic process, surfacesl space heating loadsys systemTot total% of the worldwide capacity and use. The installedcapacityis15,384 MWtandtheannualenergyuseis87,503 TJ/year, with a capacity factor of (in the heating mode).Almost all of the installations occur in North America andEurope, increasing from 26 countries in 2020 to the present 33countries. The equivalent number of installed 12 kW units(typical of US and Western European homes) is approximately million, over double the number of units reported for 2020.The size of individual units, however, ranges from kW forresidential use to large units of over 150 kW for mercialand institutional installations.During the last decade, a number of investigations have beenconducted by some researchers (. [4,6–13]) in the design,modelling and testing of GSHPs and solar assisted heat pumpsystems. The study reported here includes: (i) The performanceexperimentalevaluationofaverticalsolarassistedgroundsourceheat pump system with R22 as the refrigerant in the heatingmode. A flattype solar collector was directly in