Inlet Water Research Articles

Structure optimization and fertilizer injection performance analysis of a non‐axisymmetric Venturi injector

AbstractTo improve the fertilizer injection performance of a non‐axisymmetric Venturi injector (NAVI), the effects of the contraction angle, diffusion angle, throat diameter and tilt angle of the injection pipe on the fertilizer injection performance of NAVI were examined. Based on the test, the original NAVI was optimized, and the fertilizer injection performance of NAVI before (F1) and after (F2) optimization was compared. Then, a non‐axisymmetric Venturi injector with arc diffusion (F3) was proposed. The results showed that when the water inlet diameter of the non‐axisymmetric Venturi injector was 25 mm, the optimal structural parameters were as follows: the contraction angle was 40°, the diffusion angle 6°, the throat diameter 7 mm and the tilt angle of the injection pipe was 120°. Compared with F1, the injection rate and fertilizer injection efficiency of F2 increased by 21–66 and 27–79%, respectively. Changing the diffusion section of NAVI into an arc structure was conducive to reducing the vortex area size by 11% and improving the injection rate by 20–62%. The results can provide an important reference for the structural design of Venturi injectors.

Modeling and experimental investigation on a gas engine-driven heat pump for space-heating and sanitary hot water

Utilization of gas engine-driven heat pumps (GEHP) can reduce the heavy loads on the power grid when electric heat pumps operate during the heating season. This study is to examine the performance of GEHP as a water heater with different engine speeds and water flow rates providing space-heating and sanitary hot water. When the engine speed rises from 1400 rpm to 1900 rpm, the temperature rise of water increases by 37% from 25.7 °C to 35.3 °C. Moreover, the system heat capacity rises from 71.8 kW to 97.7 kW with an increase of 36%, while the COP decreases from 3.6 to 3.0. As the inlet water flow rate an increase from 2.5 m3/h to 4.0 m3/h, the temperature rise decreases from 44.3 °C to 24.1 °C, with decreasing heat capacity from 128.8 kW to 112.1 kW. Additionally, the primary energy ratio (PER) initially increases from 1.46 to 1.50 at the engine speed of 1800 rpm, followed by a slight decrease to 1.48 when the engine speed reaches 1900 rpm. With an increasing water flow rate, the PER achieves its highest value of 1.64 at 3 m3/h and its lowest value of 1.49 at 3.5 m3/h.

An open superhydrophilic microchannel heat sink for thin film boiling with a high coefficient of performance

Currently, the existing two-phase boiling heat transfer technologies have limitations in extremely narrow spaces and cannot satisfy the high heat flux dissipation requirements of highly integrated and ultrathin devices. In this study, a high-efficiency and low-cost open superhydrophilic microchannel heat sink with a micro/nanocomposite structure, negligible pumping energy, and a high coefficient of performance (COP) was achieved. The wettability and microscopic morphology of the different heat sinks as well as the variation in the critical heat flux (CHF) and heat transfer coefficient (HTC) at different mass fluxes were discussed. When the mass flux was 0.05 kg/m2⋅s, the CHF of the microgrooved composite nanostructured copper (MCNC) heat sink was 173.90 W/cm2, which was 182.80% higher than that of the smooth copper (SC) heat sink and 20% higher than that of the microgrooved copper (MC) heat sink. In addition, the highest CHF of 325.90 W/cm2 was obtained for the MCNC at a 0.15 kg/m2⋅s mass flux. The high CHF of thin film boiling was achieved at a low inlet water pressure. This resulted in a COP of 695,600 for this boiling method, which is a larger value than that in most reports thus far. This study provides a preliminary investigation of the thin film boiling performance for an open microchannel. This may provide a new solution to the challenge of high heat flux dissipation in extreme spaces.

Simple Empirical Relation for an Evacuated-Tube Solar Collector Performance Prediction from Solar Intensity

In this paper, the effect of solar intensity on the heat pipe tip temperature in a heat pipe type—evacuated-tube solar collector (HP-ETSC) was investigated. A simple relation was proposed, relating the solar intensity to the heat pipe tip temperature generated from the experimental data. This simple empirical relation was applied in a set of heat transfer equations derived to predict the heating medium temperature at the manifold outlet of the evacuated-tube solar collector. The calculated results corresponding to two types of heating medium, i.e., palm oil and water, were compared with experimental results from the literature. The results show that the average error was 6.41% for the case of palm oil and 4.66% for the case of water. Based on the case of water as a heating medium fluid, it was found that the flow rate of the heating medium fluid affected the accuracy of prediction, as the percentage error increased with the heating medium flow rate. The maximum percentage error increased from only 1.83% for a water inlet flowing at a Reynolds number of about 2.4 × 103 to 15.23% for a water flow rate at a Reynolds number of about 2.6 × 104. The correction factor was added into the correlation to predict the heat transfer coefficients of heating medium fluids. With this correction factor, the maximum error could be reduced from 11.78% to 7.29% for the palm oil case and from 15.23% to 5.57% for the water case. The average errors corresponding to palm oil and water cases could be reduced to 0.74% and 1.26%, respectively.

Solar energy harvesting from the photovoltaic/thermal (PV/T) pavement: Energy performance analyses and comparison considering ground influence

Under the carbon neutrality targets, the easy-installation low-investment photovoltaic (PV) technology is vital, while the limited urban rooftop area and high building façade cost limit the onsite PV installation. Thus, harvesting solar energy from the road, namely pavement-integrated photovoltaic/thermal (PIPV(T)) technology, is promising. The 2D finite element PIPV(T) models are proposed and verified through the field test within 3% (cell temperature) and 7% (PV output) mean absolute percentage error. The parametric analyses on system designs (water tank volume, water velocity, water inlet temperature), weather conditions (solar irradiance, wind velocity), and ground boundary condition influence are conducted. The water inlet temperature acts as a minor factor, while tank volume and fluid velocity are crucial, i.e., a 32.76% thermal efficiency increase for a 125 L tank volume increase. Results show that over 0.2 L/s water flow rate is recommended for a 100 L water tank, and the solar irradiance increase adds to the thermal efficiency to 41.47% under 1000 W/m2 with 11.38% ground influence. The annual system performances for southern and northern metropolises are compared, with water tank variation considered. Results show that a small water tank leads to high temperature and low system thermal efficiency at 9.3% and 12.17% in Hong Kong and Beijing.

Transmission of clones of carbapenem-resistant Escherichia coli between a hospital and an urban wastewater treatment plant

Carbapenem-resistant Enterobacterales (CRE) constitute an urgent threat to worldwide public health. The spread of CRE is facilitated by transmission via the environment. Wastewater treatment plants (WWTPs) are considered to be important sources of antibiotic resistance and hot spots of antibiotic-resistant bacteria (ARB) which can facilitate dissemination of antibiotic resistance genes. In this study, water samples were collected over one year from a WWTP in Jinan, Shandong province, China, from different functional sites in the wastewater treatment process. Carbapenem-resistant Escherichia coli (CREC) were isolated by selective cultivation and whole-genome sequenced to investigate the occurrence and characteristics of CREC in the WWTP. A total of 77 CREC isolates were included in the study and the detection rate of CREC in the WWTP water inlet was found to be 85%. An additional 10 CREC were isolated from a nearby teaching hospital during the sampling period and included for comparison to the environmental isolates. Susceptibility testing showed that all CREC were multidrug-resistant. 6 different carbapenem resistance genes (CRGs) were detected, including blaNDM-5 (n = 75), blaNDM-1 (n = 6), blaNDM-4 (n = 3), blaNDM-6 (n = 1), blaNDM-9 (n = 1), and blaKPC-2 (n = 4). 42 CREC isolates were whole-genome sequenced with Illumina short-read sequencing. 11 of these were also sequenced with Nanopore long-read sequencing. Plasmids carrying CRGs were found to belong to IncX3 (n = 35), IncFII (n = 12), IncFIA (n = 5), IncFIB (n = 2), IncC (n = 1), and IncP6 (n = 1). Clonal dissemination of CREC belonging to ST167, ST448, and ST746 was observed between different parts of the WWTP. Furthermore, isolates from the WWTP, including an isolate belonging to the high-risk ST167 strain, were found to be clonally related to CREC isolated at the hospital. The spread of CRGs is of considerable concern and strategies to prevent environmental dissemination of this contaminant urgently needs to be implemented.

A transient mechanistic two-fluid model for Direct Contact Condensation

Intensified heat treatment, using Direct Contact Condensation (DCC), is applied in the production of dairy products to ensure a high level of food safety. The key challenge with DCC is the protein reactions and fouling that limit operational efficiency and sustainability. The use of validated, transient models to predict temperature, phase fraction and velocity gradients is essential and can improve the operation of DCC. Pilot plant scale experiments were performed for a wide range of steam mass fluxes, inlet water temperatures, water Reynolds number and channel pressures to validate a transient 1D two-fluid model. The model was tested against steady-state experimental data and showed good agreement. In addition the model was tested against transient data in which either the water flow rate was step wise decreased or the pressure was adjusted throughout the experiment. In general the model followed the experimental trend well provided that the flow inside the channel is homogeneous.

Theoretical and experimental studies for a transcritical CO2 heat pump with spirally fluted tube gas cooler

Transcritical CO2 system has been widely used in many fields to provide heating and cooling capabilities, and optimizing the structure of the gas cooler is an effective way to improve its performance. This paper presents a theoretical and experimental study of a spirally fluted tube-in-tube heat exchanger used as a gas cooler in a transcritical CO2 heat pump. The theoretical research uses numerical simulations to investigate the flow and heat transfer characteristics. The effect of the different CO2 mass flow rates, inlet pressure, and temperature on the performance of the spirally fluted gas cooler is evaluated and analyzed. The simulation results show that the spirally fluted structure can significantly improve the heat transfer performance of the CO2 side compared to the flat tube, which indicates that the spirally fluted gas cooler could be an effective way to enhance the operating performance of the transcritical CO2 system. Then experimental research is conducted in a transcritical CO2 heat pump prototype to validate the functional performance of the spirally fluted gas cooler. The effect of the different CO2 mass flow rates, inlet pressure and temperature, and the different water inlet and outlet temperatures on the performance of the spirally fluted gas cooler in the prototype are tested. The heat exchanger efficiency - number of transfer units (ε-NTU) method is employed to analyze the operating performance based on the experimental data. In addition, the exergy loss method is used to quantitatively evaluate the side-effect of the large pressure drop by the spirally fluted structure. Both the theoretical and experimental results show that the spirally fluted tube gas cooler can significantly improve the performance of the transcritical CO2 system. Besides, a heat transfer and friction coefficient correlation are established based on the experimental data for future research guidance.

Performance evaluation of a solar multi-stage humidification dehumidification desalination plant with heat recovery section

In this study, a solar multi-stage humidification-compression desalination plant with heat recovery section was experimentally studied. Since honeycomb cellulose pads are more efficient than the conventional packings, in this plant, the humidifier was filled with cellulose pads. The influence of several operating parameters on the plant performance was experimentally studied. The experiments were conducted by one-at-a-time method and the plant was optimized using the response surface methodology based on a central composite design. The results showed that increasing the temperature of the inlet water to the humidifier and the compressor pressure ratio while reducing the water-to-air mass flow ratio enhanced the gained output ratio (GOR), performance ratio (PR), and recovery ratio percentage (RR%). Besides, to improve the specific energy consumption (SEC), the temperature of the inlet water to the humidifier and water-to-air mass flow ratio should be increased while the compressor pressure ratio should be decreased. The salt concentration in the feed does not have a significant influence on the system performance. The production cost was estimated at 1.3–8.53 $·m−3 in the proposed system, which, is capable to produce demineralized water.

Experimental analysis of a commercial size bio-based latent thermal energy storage for air conditioning

Future smart and efficient energy management systems for space cooling and heating in building applications require novel solutions to store heat to decouple the energy demand and the availability of renewable energy sources. Latent thermal energy storages represent one of the most promising solutions; however, their cost-effective implementation in terms of energy and cost savings and payback time needs to be verified case by case. Thus, simplified, though accurate, performance correlations during both charging and discharging phases are strongly needed to be implemented into the different dynamic simulation tools. This work is intended to present the experimental behavior of a novel 18 kWh latent thermal energy storage that uses the roll-bond technology to efficiently store and release cold energy by exploiting the solid/liquid phase change process of 300 kg of a biobased phase change material having a melting temperature of 9 °C. The effects of the inlet water temperature and flow rate are studied to elucidate how the performance varies and to identify possible control strategies. On the basis of the experimental results, two correlations are proposed to accurately predict the performance of the latent thermal energy storage to be implemented in general dynamic simulation tools that can help in evaluating the system performance and the achievable energy and cost savings.

Hollow fiber membrane integrated water cooler: A novel liquid cooling solution

To address the issues of water–air cross-contamination, liquid droplet carryover, and high maintenance costs of traditional water-mediated evaporative cooling systems, the hollow fiber membrane integrated water cooler (MWC) is proposed as a novel liquid cooling solution. The MWC incorporates hydrophobic porous membranes that enable water vapor migration while avoiding direct contact between liquid water and air. In addition, the MWC offers advantages over conventional evaporative cooling paddings in terms of high specific surface area, corrosion resistance, and anti-scaling. To evaluate the cooling performance of a countercurrent MWC, an experimental bench was built to test its outlet water temperature under various operating conditions. The developed numerical model was verified with the measured data. Then, the influence of nine critical parameters, including operating conditions and membrane module specifications, on the outlet water temperature and cooling efficiency of the countercurrent MWC was numerically investigated. The results show that evaporative heat dissipation contributes to more than 80% of the total heat exchange in MWC. Cold and dry ambient air, high inlet water temperature, low water velocity, and high air/water ratio contribute to superior cooling capability. Moreover, the cooling performance of MWC improves with increasing fiber length, inner diameter, packing fraction, and decreasing membrane thickness. In addition, the MWC offers a cooling capacity per unit volume of up to 1094.72 kW/m3, an order of magnitude greater than conventional wet cooling towers. Overall, this work presents theoretical guidelines for optimizing the operating conditions and configuration of countercurrent MWCs.

Development of multiphase solver for the modeling of turbidity currents (the case study of Dez Dam)

Dams in semi-arid regions, like Iran's Dez dam, are losing their capacity by sedimentation. Settling sediments reduces clear water, and hydropower plants' efficiency. Reservoir sedimentation relies on turbidity currents (TC). TC head velocity, and sediment content both affect particle tracking, and the removal from reservoirs. To comprehend the TC properties of Dez dam reservoir, large-scale TC modeling is required. To represent large-scale TC, a novel solver is developed. This solver couples a modified OpenFOAM® interFoam solver with the particle concentration transport equation. Two experimental tests, and Dez dam field data were verified and calibrated. The novel solution modeled these instances utilizing a two-dimensional vertical model (width averaged) with RANS turbulence closure, despite the fact that the Dez dam reservoir has a considerable size for numerical modeling. The solver simulated four Dez Dam reservoir scenarios with different water levels. Consequently, when the inlet water depth rose four times, the TC head velocity, and distance traveled by TC doubled. TC in Dez dam is a supercritical flow with the interface instabilities based on its local Richardson number, and gradient Richardson number. Furthermore, Kelvin-Helmholtz instabilities and recirculation vortex combine clear water with TC to reduce the particle concentration.

Process steam generation from low-grade waste heat in a direct- contact adsorption heat pump based on superhydrophobic surface-modified Zeolite 13X

ABSTRACT Adsorption heat pump (AdHP) is a potential technology to recover and storage low-temperature waste heat. This paper presents an experimental research on direct low-pressure process steam generation from hot water based on superhydrophobic surface-modified zeolite 13X. The measured water contact angle of the modified zeolite is larger than 150°, which restricts free water entering the pores inside the zeolite particles. Cyclic experiments are conducted for performance evaluation. High-temperature steam (205–229°C, 0.1–0.3 MPa) is generated from hot water (72°C) in the AdHP driven by dry air (130°C). The temperature of generated steam is promoted with increasing preset steam pressure, among which the temperature is raised by about 23°C at 0.3 MPa. As the boiling point of water rises simultaneously, the sensible heat demand is increased. Thus, the mass of the steam is accordingly decreased. GTL (gross temperature lift) reaches 130°C. When the preset pressure is increased, COPh (coefficient of performance for heating) and SHP (specific heat power) for direct steam generation are decreased by 36% and 39%, respectively. One feasible option to elevate these two indicators is to increase the inlet water to near boiling water to match the change in the preset pressure. However, the GTL will be decreased based on the option. Balance should be made based on the choice of design for practical application.

Water Use and Water Saving Strategies in Dialysis, Room for Improvement?

Dialysis treatment consumes a significant amount of water and energy, which entails an important waste management effort. Those variables play a relevant role on the total cost of a dialysis session. Strict dialysis water and ultrapure dialysis fluids standards were established as a pre-requisite for online convective therapies (e.g., hemodiafiltration), improving biocompatibility of the dialysis system, reducing inflammation profile of the dialysis patients, enhancing the responsiveness to erythropoiesis-stimulating agents and thus having the potential for improved survival. The main purification step of a dialysis water treatment system is the reverse osmosis. Fouling of reverse osmosis membranes remains a major issue and all effort should be made to reduce it, to ensure a constant output. Naturally occurring waterborne filamentous fungi, yeasts, bacteria and fragments may contaminate dialysis water and, consequently, dialysis fluids. To maintain the dialysis water treatment system under proper conditions and fulfilling the dialysis fluids quality standards there is a need of a significant effort, namely in terms of cleaning and disinfection procedures of the reverse osmosis, distribution systems and dialysis machines. Improving the reverse osmosis inlet water quality profile by installing an Ultrafiltration system as a pre-treatment, could have an impact in terms of dialysis water quality outcomes, water and energy consumption, and disinfection frequency. The water treatment system efficiency is strongly influenced by the system design and reverse osmosis setup. System design (i.e., not over dimensioned) with a clear focus on increasing efficiency is mandatory if one wants to decrease the carbon footprint. Dialysis prescription (namely dialysis fluid flow rates) plays an important role in the dialysis fluid consumption and consequently the water consumption. A more environmentally friendly dialysis can be influenced by optimization of the current technology and development of innovative technology, and by the adoption of a conscious and coherent behavior of all persons involved in the daily routine of a dialysis unit.

4E analysis and multi-objective optimization of compression/ejection transcritical CO2 heat pump with latent thermal heat storage

To promote the goal of peak carbon dioxide emissions and carbon neutrality, low-energy consumption buildings require innovative technologies and efficient energy management. In this paper, the multi-objective optimization and the energy, exergy, economic and environmental (4E) analyses of the compression/ejection transcritical CO2 heat pump with latent thermal storage (TPE-LTES) system are conducted, and the influences of crucial parameters on the system performance are evaluated. The results show that the optimal comprehensive COP and annual hot water production (mDHW) of the TPE-LTES system are 3.59 and 3110 tons, respectively. Then, the comprehensive exergy efficiency of the TPE-LTES system owns 48.93 % higher than that of the heat pump unit. Furthermore, the optimal life-cycle cost (LCC) and life-cycle CO2 emissions (LCCE) of the TPE-LTES system are 708,073 CNY and 575,512.79 kg, respectively. Moreover, with constant discharge pressure, the evaporative superheat can be preferentially increased to reduce the system LCC and LCCE. Finally, the comprehensive COP and exergy efficiency of the system can be improved by increasing the inlet water temperature, while the increasing inlet water flow rate is the least desirable. This work is helpful to promote the research and application of latent heat storage unit integrated into air source heat pump.

Safe-efficient operation strategies for integrated system of photovoltaic and proton exchange membrane electrolysis cells

Proton exchange membrane electrolysis cells (PEMEC) can be utilized to produce hydrogen using renewable energy. In this paper, photovoltaic (PV) integrated with PEMEC is developed for hydrogen production. Based on the operation characteristics of PV and PEMEC, two operation strategies (Strategy 1 and Strategy 2) are proposed to regulate membrane temperature lower than 353.15 K under different solar irradiations. For Strategy 1, the water flow rate is firstly increased and then the inlet water temperature is reduced in the morning with increasing irradiation; and only increasing the inlet water temperature in the afternoon. While for Strategy 2, only reducing the inlet water temperature is adopted in the morning, and increasing the inlet water temperature in the afternoon. Results show that Strategy 1 outperforms Strategy 2 in terms of higher energy efficiency of 5.38% and exergy efficiency of 5.46%. However, the specific energy consumption is higher with Strategy 1 owing to higher pump power consumption, which is 6.15 kWh/Nm3.

Experimental hydraulic parameters of drainage grate inlets with a horizontal outflow in the broad-crested weir mode.

The accurate assessment of discharge coefficients for different types of water inlets is crucial for minimizing modelling errors in drainage systems thus reducing the risk of flooding in adjacent areas. This study experimentally investigated the hydraulic characteristics of gully grate inlets with water seal and horizontal outflow, with nominal outlet pipe diameters of 100 and 150 mm, using a laboratory setup that meets the requirements of a special European regulation. Transition depths from the weir to the orifice mode were determined, and it was found that the perforated grates significantly increased the hydraulic resistance compared to the bar grates, resulting in a corresponding decrease in the discharge capacity of gully inlets. Power-law relationships between the weir discharge coefficient and gauge head were obtained for both bar and perforated grate inlets, as well as between the discharge coefficient and Froude number at the perimeter of grate inlets. These findings provide important insights for optimizing the design and performance of water inlets, particularly in the weir mode, which is critical for the proper functioning of drainage systems.

Thermal Analysis of Novel Pebble Absorber Based Solar Thermal Collector

The fluid flow rate of the heat absorbing medium plays a crucial role in the performance of the collector. Studies were carried out with varying fluid flow rates of 0.01 kg/s, 0.013 kg/sec and 0.016 kg/sec respectively for different days from 8:00 hour to 18:00 hour. The input parameters considered for the computational modeling are i) Solar radiation (I) ii) Ambient temperature (Ta) iii) Inlet water temperature (Ti) and iv) Mass flow rate (mf). Experiments carried out using coated and uncoated pebbles as absorber along with a conventional flat plate collector. The efficiency of the solar thermal collector increases with flow rate and incident radiation. The coated pebble absorber collector is more efficient than the uncoated pebble absorber collector and less efficient than the conventional metal absorber collector at above mentioned flow rates. The total average efficiency of coated absorber collector was 67.036%, 51.35% for the uncoated absorber collector and 72.857% for the conventional copper absorber collector.

Geometry modification of a vertical shell-and-tube latent heat thermal energy storage system using a framed structure with different undulated shapes for the phase change material container during the melting process

This study aims to modify the melting performance of a vertical latent heat double-pipe heat exchanger by geometry modification of the phase change material (PCM) container. To modify the configuration of the PCM container placed in the outer tube, a framed structure is embedded in the inner surface of the outer tube. Different framed structures i.e. smooth, arc-shaped, reverse arc-shaped, and zigzag-shaped structures are examined and compared with that of the unframed enclosure. Moreover, different numbers of pitches are also examined. The results show that the melting duration drops by almost 55 % and the thermal energy storage rate improves by 115 % using a smooth framed structure for the PCM container compared with that of using an unframed structure. The thermal energy storage rate and melting time are ∼9.5 W and 244.4 min, respectively, for the system using an unframed structure. The analysis of the pitch number for the zigzag-shaped structure reveals that increasing the number of pitches from 0 to 11 enhances the thermal energy storage rate by 36.5 %. The evaluation of different shapes of the framed structure shows that the case with reverse arc-shaped structure is the most enhanced unit which has the thermal energy storage rate of ∼34 W and melting time of 63.15 min heated by water at the Reynolds number 1000 and inlet water temperature of 50 °C. The sensitivity analysis of the HTF characteristics reveals that by increasing the Re from 1000 to 2000, the thermal energy storage rate increases by around 6 W. Furthermore, by increasing the inlet temperature of HTF from 50 °C to 55 °C, the thermal energy storage rate enhances by around 10 W. This paper shows the capability of geometry modification in enhancing the thermal energy storage rate of the systems.

Feasibility and investigation of residential HVAC system with combined ground source heat pump and solar thermal collectors in different climates of Iran

Geoexchange is one of the most energy-efficient, environmentally clean, and cost-effective space-conditioning systems available on the market. Seasonal storage of solar energy in geothermal boreholes is sharply interesting as a means of heating and cooling in buildings with different applications. In this study, a closed-loop geo-exchange and solar thermal system with two different heat exchangers are examined in an energy-efficient house. TRNSYS, a simulation software tool, was used to model the yearly performance of the hybrid ground-source heat pump (GSHP) system. Two different types of ground heat exchangers, e.g., tube-in-tube and U-tube were employed. The mass flow rate through the heat exchangers and the solar collector was examined to choose the best scenario for each of them. The economic benefits of a gray water heat recovery system and solar collector were studied; the results show that 517 and 536 US Dollars/Year can be saved from each of them, respectively. System performance analysis was carried out in different cities with various climates in Iran. Moreover, a complete economic assessment was evaluated for all cases. The results show that for the same inlet water temperature to GSHP, the tube-in-tube heat exchanger can pass 45% more flow than the U-tube heat exchanger for the same size as the HP. Furthermore, in the absence of the solar collector, a 2.7 × 108 kJ increase was conducted in the auxiliary heater component yearly. Finally, four different climates were evaluated for the launching of the GSHP system with a solar thermal collector. The hot and dry climate with 27 °C fluid inlet to a heat pump, a total borehole depth of 220 m, and an initial cost of $ 25,047 was selected as the most appropriate weather conditions for launching the system in Iran.