Water Output Research Articles

Evaluation and Addition of Waste Water Treatmant Plant Units in West Lombok Regency Hotel

The development of hotels in Lombok is very drastic, especially in tourist areas. In carrying out their activities, hotels require large amounts of water to meet the needs of guests and employees; besides that, water use in a hotel is also seen in the supporting facilities. Using large amounts of clean water will also produce large quantities of wastewater. This research aims to evaluate wastewater treatment installations at XY Hotel. The method used in this research is a field study followed by an analysis of water quality, process, and output. Based on the evaluation results, the Wastewater Treatment Plant at Hotel Aerobic has capacities of 20 m3/day, 15 m3/day, and 2 m3/day respectively.

Design and simulation of an intelligent irrigation system using fuzzy logic

Farmers in developing countries employ various irrigation methods ranging from traditional techniques such as the use of irrigation cans to modern pressurized systems while irrigating short-seasoned crops that require continuous water supply especially during the dry season. Inspite of being cheap and easy to use, farmers find it challenging to optimize farming costs through the application of the neccessary amount of water onto the crops, leading to crop water logging and hence roting. Due to the growing demand for agricultural products, there was need to develop an irrigation system that considers the amount of moisture in the soil, air temperature and light intensity, which are important parameters in plants’ growth. This dissertation therefore presents the design, simulation and implementation of an intelligent irrigation system, utilizing multiple sensors and a fuzzy logic controller to optimize water usage while ensuring high farming yields. The system design integrates light, temperature, and soil moisture sensors to monitor environmental conditions and soil moisture content in real-time. The operation of the irrigation system is governed by a set of one hundred twenty five (125) fuzzy rules that process the inputs from these sensors, determining the appropriate irrigation duration based on the prevailing light intensity, ambient temperature, and soil moisture levels. The fuzzy logic controller employs a combination of membership functions and rule-based inference to handle the relationships between the environmental parameters and the irrigation needs of the soil. By continuously analyzing the data from the sensors, the system dynamically adjusts the water output, ensuring optimal soil moisture levels while minimizing water wastage. Additionally, the system is equipped to send notifications in form of calls to a smartphone connected to the GSM network in case of critical conditions or system malfunctions. Experimental results demonstrate the ability of the intelligent irrigation system to dynamically adjust the amount of water being pumped into the garden basing on the prevailing soil moisture, temperature and light intensity.

Going upstream: a pluri-ontological analysis and proposal for Brazilian participatory water governance

ABSTRACT Despite the growing emphasis on ontological pluralism in environmental policy debates, innovation within national state environmental governance and management remains limited. This article outlines a conceptual framework for ontological inclusion and exclusion to examine constraints and opportunities in Brazilian participatory water governance. This involves an ontological policy cycle of the Suaçuí state river basin, a participatory process for water-body classification, and a water-body-classification instrument. River ontologies of the Suaçuí river basin and participatory process were found to be excluded from the water-body classification instrument through various practices and modes of exclusion. Relational ontologies, both indigenous and non-indigenous, were excluded. Building on the analysis of how ontological exclusion occurred, speculative design was engaged to critically imagine a pluralist ontological proposal. A database with diverse water inputs and outputs for more sustainable and inclusive planning is envisaged. This proposition grounds reflections on challenges for ontological inclusion in the context of political, economic, and social inequalities. Ontological inclusion and exclusion complement classic concepts of social and epistemic inclusion with distinct normative demands and propositions for established participatory environmental governance.

Assessing the potential of geothermal energy in Cambrian complexes for renewable energy transition in Lithuania

Several depleted Cambrian oil fields in Lithuania, with water-cuts reaching 99 %, present promising opportunities for geothermal energy utilization. This study focused on Lithuania’s Cambrian reservoir complex, which has the highest water production rates. The study aimed to explore the advantages of horizontal wells, a technology not previously employed for geothermal production in Lithuania, over traditional vertical wells. To optimize field development, various scenarios were evaluated using mechanistic models, with insights subsequently applied to real field conditions. The results from the mechanistic model demonstrated that horizontal wells outperform vertical wells in both water production and power generation. Furthermore, increasing fracture intensity was shown to enhance water output and power generation by operating the wells at pressures above fracture propagation, facilitating re-injection. However, the study also emphasized the importance of thorough reservoir characterization and modeling to account for geological complexities and improve production outcomes. In conclusion, the research underscores that horizontal wells offer several advantages over vertical wells for geothermal energy production. These include increased water production, higher power generation, reduced drilling costs, and enhanced operational efficiency. These benefits align with technological advancements observed in the hydrocarbon industry, making horizontal wells a viable solution for maximizing geothermal energy potential in Lithuania’s depleted oil and gas fields.

Sustainable and Self-Sufficient Fresh Water Through MED Desalination Powered by a CPV-T Solar Hybrid Collector: A Numerical and Experimental Study

The effects of global warming are severely recognizable and, according to the OECD, 47% of the world’s population will soon live in regions with insufficient drinking water. Already, many countries depend on desalination for fresh water supply, but such facilities are often powered by fossil fuels. This paper presents an energy self-sufficient desalination system that runs entirely on solar power. Sunlight is harvested using parabolic trough collectors with an effective aperture area of 1.5 m × 0.98 m and a theoretical concentration ratio of 150 suns, in which a concentrator photovoltaic thermal (CPV-T) hybrid-absorber converts the radiation to electricity and heat. This co-generated energy runs a multi-effect distillation (MED) plant, whereby the waste heat of multi-junction concentrator solar cells is used in the desalination process. This concept also takes advantage of synergy effects of optical elements (i.e., mirrors), resulting in a cost reduction of solar co-generation compared to the state of the art, while at the same time increasing the overall efficiency to ~75% (consisting of an electrical efficiency of 26.8% with a concurrent thermal efficiency of 48.8%). Key components such as the parabolic trough hybrid absorber were built and characterized by real-world tests. Finally, results of system simulations, including fresh water output depending on different weather conditions, degree of autonomy, required energy storage for off-grid operation etc. are presented. Simulation results revealed that it is possible to desalinate around 2,000,000 L of seawater per year with a 260 m2 plant and 75 m3 of thermal storage.

Tubular Solar Stills: Review

This study discusses tubular solar still concepts, designs, and performance improvement for sustainable water purification. A greener alternative to traditional methods, tubular solar stills use sun energy for evaporation and condensation. Advances in phase transition materials, reflectors, and nanotechnology improve heat efficiency and water output. The research shows their adaptability and ability to sustainably address global water scarcity in remote and disaster-affected areas. This study examines tubular solar still concepts, designs, and performance optimization for sustainable water purification. Tubular solar stills use sun energy for evaporation and condensation, a greener option. New technologies including phase change materials, reflectors, and nanotechnology boost heat efficiency and water production. Applications from distant to disaster-stricken locations show their versatility and capacity to sustainably manage global water constraint.

Hybrid modelling framework for ozonation and biological activated carbon in tertiary wastewater treatment.

Despite water being a significant output of water and resource recovery facilities (WRRFs), tertiary wastewater treatment processes are often underrepresented in integrated WRRF models. This study critically reviews the approaches used in comprehensive models for ozone (O3) and biological activated carbon (BAC) operation units for wastewater tertiary treatment systems. The current models are characterised by limitations in the mechanisms that describe O3 disinfection and disinfection by-product formation, and BAC adsorption in multi-component solutes. Drawing from the insights from the current O3, BAC, and WRRF modelling approaches, we propose an integrated O3-BAC model suitable for simulating dissolved organic carbon (DOC) and micropollutants removal in the O3-BAC systems. We recommend a hybrid modelling approach in which data-driven models can be integrated to compensate for structural limitations in mechanistic models. The model is developed within the activated sludge model (ASM) framework for flexibility in coupling with other WRRF models and hence facilitates developing system-wide WRRF models for wastewater reclamation and reuse systems.

Multi-Timescale Scheduling Optimization of Cascade Hydro-Solar Complementary Power Stations Considering Spatio-Temporal Correlation

The water-PV hybrid generation system is an effective approach to promoting renewable energy integration; however, most existing hydropower stations are run-of-river type with limited annual regulation capacity. Enhancing the PV absorption capacity of such run-of-river hydropower is thus crucial for achieving localized renewable energy utilization. This study proposes a multi-timescale optimization scheduling method for cascade water-PV complementary systems, accounting for spatiotemporal correlations. First, using historical data and Frank-Copula based correlation analysis, we identify the spatiotemporal interactions between water and PV outputs to generate numerous scenarios that capture the coupled characteristics of water-PV generation within the watershed. Considering constraints related to reservoir capacity, water level, flow rate, and individual unit output, a multi-timescale optimization scheduling model is formulated with a single unit as the smallest dispatch unit. To improve computational efficiency, a triangular weighting method is introduced to simplify complex constraints. Finally, a case study within a watershed in Southwest China validates the model's effectiveness and reliability, providing a valuable reference for enhancing PV absorption capacity through the utilization of run-of-river cascade hydropower.

Sustainable Water Purification Techniques: A Review Of Solar-Based Desalination Methods

Global water scarcity continues to pose a critical challenge, driving the need for sustainable water purification solutions. Solar desalination has emerged as a promising approach due to its reliance on renewable solar energy and minimal environmental impact. This study systematically reviews and synthesizes findings from a comprehensive set of 100 peer-reviewed articles to evaluate advancements in solar desalination technologies, including solar stills, photovoltaic-powered reverse osmosis (PV-RO) systems, hybrid solar desalination, and the application of nanotechnology. The review highlights significant progress in improving the efficiency, scalability, and cost-effectiveness of these systems, particularly through innovations such as multi-stage designs, advanced membrane materials, energy recovery devices, and the integration of phase change materials (PCMs) for thermal storage. Additionally, the incorporation of nanomaterials has proven effective in enhancing thermal conductivity and reducing fouling, thereby optimizing water output and system longevity. Findings also reveal the substantial environmental benefits of solar desalination, which can reduce the carbon footprint of water production by up to 70%, aligning with the United Nations Sustainable Development Goals (SDGs) related to clean water access and climate action. However, challenges remain, particularly concerning the initial capital costs and the need for further technological advancements to achieve widespread adoption. This review underscores the critical role of continued research, innovation, and supportive policies in scaling solar desalination technologies as a sustainable solution to global water scarcity.

Abstract 4137996: Effects of Empagliflozin on diuresis in heart failure: Results from the CINNAMON-study and in-vivo experiments

Background and Purpose: Heart failure is associated with renal dysfunction suggesting a pathophysiological link between heart and kidney. Empagliflozin, a SGLT2 inhibitor, showed beneficial effects on both cardiovascular and renal endpoints. However, mechanistically, it is unclear if empagliflozin-dependent kidney protection is mediated via inhibition of tubular SGLT2 or more indirectly via improved cardiac function. We hypothesized that Empagliflozin treatment improves left ventricular ejection fraction (LVEF) independent of diuretic effect of renal SGLT2 inhibition. Methods: We evaluated NTproBNP, hematocrit, hemoglobin and bodyweight in patients with HF with reduced (n=32) and preserved ejection fraction (n=59) after 30 and 180 days (prospective, single-arm CINNAMON-study, DRKS00031101). Furthermore, we conducted transverse aortic constriction (TAC) or sham surgery in C57BL/6J (wildtype, WT) and SGLT2 deficient mice (SGLT2 -/- ). Animals received either Empagliflozin (10 mg/kg bodyweight) or vehicle by daily oral gavage. Water intake and output was evaluated by metabolic cages at 10 weeks and cardiac function by echocardiography. Results: Empagliflozin treatment reduced NT-proBNP levels and increased hematocrit and hemoglobin levels especially in patients with reduced ejection fraction (Fig. A-C). Surprisingly, there was no change in body weight (Fig. D), which would be expected if the diuretic effects were dominant. In mice after 10 weeks, echocardiography confirmed TAC induced pressure-overload, leading to reduced LVEF. Empagliflozin attenuated changes in LVEF (Fig. G) and improved diastolic dysfunction (isovolumetric relaxation time, data not shown). To test if direct inhibition of SGLT2 in the heart and kidney is mechanistically involved, TAC surgery was repeated in SGLT2-deficient mice (SGLT2-KO). In fact, exposure to TAC resulted in comparable reduction of LVEF in SGLT2-KO and Empagliflozin prevented this deterioration similar to WT mice (Fig. G vs. I). Surprisingly, Empagliflozin did not increase drinking and urine volume neither in wildtype nor in SGLT2 deficient mice, suggesting a mechanism of cardioprotection independent of diuretic effects. Conclusion and Outlook: This is the first study investigating the role of SGLT2 in Empagliflozin treated patients and mice with heart failure. Importantly, empagliflozin treatment prevented deterioration of LVEF independent of the presence of SGLT2 and diuresis.

Research on the Designing and Experimental Performance Evaluation of a New Sand Control Screen for Argillaceous Fine Silt Gas Hydrate Reservoirs

Argillaceous fine silt hydrate reservoirs have a clay content of 20–25% and a median sand particle size of 10–15 um. Sand control is extremely difficult, restricting the continuous and stable testing of gas hydrate. This paper focuses on the sand production mechanisms, plugging characteristics, and clogging mechanisms of these hydrate reservoirs. Based on the actual characteristics of hydrate reservoirs, it presents an understanding of the sand production mechanism of argillaceous fine silt. The characteristics and properties of three different sand control methods and six kinds of sand control screens are analyzed. Clear design concepts for sand control screens in argillaceous fine silt hydrate reservoirs are proposed. Two types of new sand control screen with metal filter screens and pre-filled screens have been innovatively designed, and the sand control ability and overflow performance of the screens are evaluated using the meter production index conversion method. Sand production simulation and comprehensive experimental evaluation and analysis of the flow performance of seven kinds of screens (themselves from two categories of screens) were carried out using a self-made special experimental testing device. The experimental results show that the newly designed screens have good flow performance and can meet the requirements of a certain gas production rate. Specifically, Class A metal screens (60/70 mesh) and Class B pre-filled screens (40/70 mesh) have excellent sand control capacity and flow performance, with 10 g sand output and 300 L total water output, thus fulfilling the sand control requirements and achieving the purpose of “effective sand control, prevention without plugging, and continuous stable production” of argillaceous fine silt gas hydrate reservoirs. They therefore provide a reference for future research on sand control and new screen designs for argillaceous fine silt hydrate reservoirs.

Operation study of the photovoltaic thermal heat pump integrated energy system under trigeneration condition and harsh conditions

In recent years, the photovoltaic thermal heat pump has gained significant attention as a near zero-carbon energy technology, due to the comprehensive ability to provide heating in winter, cooling in summer, photovoltaic power generation and domestic hot water throughout the year. However, owing to the incomplete research on the system operating characteristics in trigeneration condition and harsh conditions, the production performance and operational stability of the photovoltaic thermal heat pump were not widely recognized. In view of the above problems, the following studies were conducted in this paper: First, the integrated energy system based on the modular photovoltaic thermal heat pump was designed and constructed. Then, the system operation in severe hot and cold season was carried out and the operational stability of the system under harsh operating conditions was demonstrated sufficiently. Afterwards, the operation of the system under the continuous trigeneration operation were analyzed. During the 7-day trigeneration operation, the average hot water output was 12.12 tons and the average photovoltaic power generation was 88.5 kWh in the daytime heating operation. Besides, the average coefficient of cooling performance was 2.32 in the nighttime cooling operation and the effective cooling-supply time of the system was approximately 4 h.

Unveiling the Dynamics of Canopy Transpiration: A Novel Model Integrating Stomatal and Aerodynamic Resistance in Semi-Humid Forests

Canopy–atmospheric water vapor output resistance (gs) is a key parameter in researching forest canopy transpiration. It is important for quantifying the water vapor exchange in forest ecosystems. However, the method by which gs is determined has been controversial, and it cannot precisely represent water vapor exchange. This study aimed to develop a model to quantify the water vapor resistance between the canopy and the atmosphere in Platycladus orientalis (P. orientalis) forests using sap flow and meteorological factors monitoring data. The resistance model was constructed using the relationship between canopy stomatal resistance (gc) and aerodynamic resistance (ga) from the mechanism perspective, and sap flow data and measurements of meteorological variables were used to model the stomatal and aerodynamic resistance of the canopy. The results indicate that the canopy-atmospheric water vapor output resistance was closer to the measured values and showed a unimodal curve in the diurnal scale, and this change could provide more accurate measurements of tree transpiration. At the same time, the canopy-atmospheric water vapor output resistance was strongly influenced by wind speed and PAR when 0.2 m/s < u < 0.4 m/s (R2 = 0.871, p < 0.01). The stomatal and aerodynamic resistance were also both strongly influenced by wind speed, with the proposed model achieving a high degree of fit (R2 = 0.949, p < 0.01), providing a new tool for analyzing forest transpiration. This research provides a new perspective and technical reference for clarifying the mechanism of forest canopy water output.

Performance evaluation and multi-objective optimization of hydrogen-based integrated energy systems driven by renewable energy sources

This study proposes an integrated energy system using hydrogen storage to realize the efficient utilization of renewable energy sources and reduce the fluctuation when renewable energy is connected to grid. The system utilizes solar and wind energy to realize hydrogen production, desalination, and CCHP. First, the energy, exergy, and economic evaluations for the proposed system are carried out, and then an in-depth analysis of the key operating parameters is performed. The system achieves energy efficiency, exergy efficiency, and cost rate of 48.49 %, 19.98 %, and 7.969 $/h, respectively. And the exergy analysis shows that the main exergy destructions are caused by the parabolic trough solar collector and the transcritical CO2 power cycle. The parametric analysis demonstrates when solar radiation flux and wind speed increase, the exergy efficiency and hydrogen production are increased, but the cost rate is increased accordingly. Finally, two sets of multi-objective optimization schemes are performed combining the artificial neural network with the Non-dominant genetic algorithm-II. For the optimized fresh water output, cost rate, and exergy efficiency, it is achieving improvements of 51.73 %, 8.4 %, and 3.6 %, and for the optimized hydrogen production, cost rate, and exergy efficiency, it is increased by 12.53 %, 0.564 %, and 0.75 %, respectively.

Dynamics of soluble salts in cooling systems of circulating water supply

A model of the dynamics of soluble salts in the water of cooling systems of circulating water supply was developed based on mass balance principles. The proposed model is expressed in a general form under the assumption of a constant volume of circulating water and non-stationary input and output flows. The model accounts for scenarios where the concentration of soluble salts exceeds their concentration in the circulating water, thereby considering the technological necessity to change the system's power source in the event of an emergency at the feedwater treatment facilities. The developed model enables accurate prediction of the water-chemical regime in both existing and new recirculating cooling systems, sufficient for engineering calculations. It also facilitates the selection of optimal management strategies for such systems, including stabilization methods for recirculating water, feedwater preparation, blowdown volumes, etc. The model was validated under laboratory conditions for cases of concentration and dilution of highly soluble NaCl salt, with an observed error margin not exceeding 2%, attributed to experimental and instrumental factors. The variation in the concentration factor was analyzed for different blowdown rates, assuming initial equality of soluble salt concentrations in feedwater and circulation water. It was shown that establishing dynamic equilibrium between the circulation and feed waters can require dozens or even hundreds of circulation cycles for blowdown rates of 1–4%, and this system inertia must be considered during operation and when forecasting the performance of cooling systems with circulating water supply.

Integrated effects of furrow irrigation systems and irrigation regimes on water productivity of onion (Allium cepa L.) crop in a semi-arid area

Dwindling water resources with inept field water management impends sustainable agricultural production in semi-arid areas of Ethiopia. Thus, the adaption and adoption of improved irrigation water running lines are indispensable and imperative to recuperate water productivity in areas where water resources are inadequate. The ground experiments were pointed to elucidate the weight of conventional, alternate, and fixed furrow irrigation systems under irrigation levels of 100 %, 70 %, and 40 % of crop evapotranspiration (ETc) on onion growth, yield, water productivity, and economic return in Alage, Central, Ethiopia. The field trials were conducted at nine treatments arranged in a randomized complete block design with three replications and water was managed at fixed intervals with variable depth approach. The result illustrated that furrow systems in conjunction with irrigation levels had a weighty pertain (P < 0.05) on onion growth, yield, water productivity, and economic return. The highest yield of 30.75 ton ha−1 was achieved at conventional furrow irrigation with 100%ETc dictated to zero water saving subsequently, the crop and irrigation water productivity dropped with the values of 6.86 and 5.61 kg m−3 respectively. The diminished yield of 6.39 ton ha−1 obtained at fixed furrow irrigation with 40%ETc conquered the saved water output lastly, the crop and irrigation water productivities demoted with values of 6.87 and 5.70 kg m−3 respectively. Nevertheless, 24.93ton ha−1 of ideal yield was obtained under alternative furrow irrigation with 100%ETc and the 50 % hoarded water was higher than the yield decline. Consequently, the crop and irrigation water productivities rose with values of 10.96 and 9.09 kg m−3 respectively. Eventually, the saved water opened for 0.03ha extra irrigable area that will onward to the highest total expected yield of 37.40 ton ha−1 as compared with all other treatments. Under conventional furrow irrigation with 100%ETc, the obtained yield dominated the wastewater accordingly, the highest net return of 668484ETB ha−1 and benefit-cost ratio of 3.63 was achieved. Besides, the unbearable yield penalty under fixed furrow with 40 % headed to negative net return and lowest befit cost ratio as related with other treatments. However, further economic results confirmed that the 50 % saved water under alternative furrow with 100 % can recompense for the net return reduction that will make this trial combination preferable as compared with other treatments. Other results also recommended that, under water-limiting and inefficient field water governing conditions, alternative furrow irrigation with 100%ETc can be the ideal blend to enhance water productivity in semi-arid regions of Ethiopia and elsewhere that share similar agroclimatic conditions.

Performance optimization for solar photovoltaic thermal system with spiral rectangular absorber using Taguchi method

Solar collector systems efficiently transform sunlight into energy that may be used to meet various needs. This research aimed to use the Taguchi method to determine the ideal operating parameters for a solar thermal collector with a rectangular spiral absorber. Controllable parameters including mass flow rate, solar radiation, and absorber design were manipulated during the energy recovery process, and features like PV temperature and outlet water temperature were used to assess the system’s effectiveness. The findings indicate that certain criteria significantly affect response indicators. The observed percentage contribution of absorber design, solar radiation, and the mass flow rate was 69.19%, 27.99%, and 2.83% in PV surface temperature. In comparison, the individual percentage contributions were 73.63%, 13.51%, and 10.57% for absorber design, solar radiation and mass flow rate for water output temperatures. The present model’s R2 values for PV and outlet water temperatures are 97.24% and 99.67%, respectively. The Predictive regression model was found in fine harmony and the maximum percentage error is limited to 0.68%. The maximum analytical electrical efficiency was observed with a spiral rectangular absorber of 14.57% at the lowest mass flow rate of 0.04 kg/s at the lowest radiation level of 600 W/m2. In comparison, maximum analytical thermal efficiency was observed with a spiral rectangular thermal absorber of 63.56% at the highest flow rate of 0.06 kg/s and the highest solar radiation level of 1000 W/m2. The analytical and experiment findings were in better agreement in this study, with the highest relative error of 7.52%. According to the study’s findings, the rectangular absorber-based PVT system is at its best at a higher mass flow rate to lower PV temperature and boost thermal energy recovery via water. The present research work can be extended for exergy, environmental, and economic feasibility analysis.

Enhancing conical solar still performance using high conductive hollow cylindrical copper fins embedded by PCM

The present study aims to enhance the efficiency of the conical solar distiller in producing water during both day and night. This will be achieved through design enhancements, such as increasing the surface area of the distiller to maximize solar energy absorption and improve condensation rates. High thermal-conductivity cylindrical fins have been used, and their role will be investigated. These fins may be hollow and extended, with or without the inclusion of phase change material (PCM). Consequently, copper tubes are positioned at the base of the distiller basin, both with and without the inclusion of phase-changing paraffin wax material inside the hollow tubes. A comparison is made between the performance of three configurations: the first configuration is traditional, the second configuration includes fins without the incorporation of PCM, and the third configuration includes PCM-based fins. This comparison is crucial as it provides a clear understanding of the impact of each design enhancement on the distiller’s performance. The study findings indicated that the arrangement with hollow fins filled with PCM had the highest level of freshwater output. Furthermore, the results showed that the combined output of conical solar distillers equipped with fins made of copper tubes, both with and without PCM, were 7.50 and 6.75 L/m2/day, respectively. The cumulative production of conventional conical distillers is 4.85 L/m2/day. Freshwater output improved by 54.64 and 39.17 % when using hollow copper tubes with and without PCM within 24 h, compared with the conventional configuration. During night-time hours, it was observed that the freshwater output of distilled water from salt water significantly improved by 550 % when utilizing copper tubes loaded with PCM, compared to distillation using empty copper tubes. The maximum daily efficiency of conical distillers with fins with and without PCM were 73.6 % and 80.3 %, respectively. These results showed that conical distillers using copper tubes hollow filled with PCM represent good options for obtaining higher performance than distillation.

Radiogenic Strontium‐ and Uranium‐Isotope Tracers of Water‐Rock Interactions and Hydrothermal Flow in the Upper Geyser Basin, Yellowstone Plateau Volcanic Field, USA

AbstractNatural radiogenic isotopes (primarily 87Sr/86Sr) from hot springs in the Upper Geyser Basin of the Yellowstone Plateau volcanic field and associated rocks were used to evaluate groundwater flow patterns, water‐rock reactions, and the extent of mixing between various groundwater sources. Thermal waters have very low uranium concentrations and 234U/238U activity ratios near 1.0, which limit their utility as tracers in this reducing setting. Thermal waters have higher Sr concentrations (&lt;22 ng/g) and a wide range of 87Sr/86Sr values that vary both temporally at individual discharge sites and between adjacent springs, indicating that conduits tap different subsurface reservoirs to varying degrees. Sr from local rhyolites have 87Sr/86Sr compositions that bound the range of values observed in groundwater throughout the basin. Non‐boiling springs on the west flank of the basin discharge water with low 87Sr/86Sr consistent with flow through young volcanic rocks exposed at the surface. Boiling springs in the central basin have higher 87Sr/86Sr values reflecting interactions with older, more radiogenic volcanic rocks. Variability in upwelling thermal waters requires mixing with a low 87Sr/86Sr component derived from young lava or glacial sediments, or more likely, from deeper sources of hot groundwater circulating through buried Lava Creek Tuff having intermediate 87Sr/86Sr. Isotope data constrain basin‐wide output of thermal water to 110–140 kg·s−1. Results underscore the utility of radiogenic Sr isotopes as valuable tracers of hydrothermal flow patterns and improve the understanding of temperature‐dependent water‐rock reactions in one of the largest continental hydrothermal systems on Earth.

Research and Experiment on Efficient Fracturing Technology of Tight Gas in Qaidam Basin

Abstract The lithology of the Huangguamao block reservoir in the Qaidam Basin is complex and dense. The difference between gas and water is not obvious. The gas reservoir has the characteristics of low porosity, low permeability, low saturation, and coexistence of gas and water. The problem of water output after fracturing and short stable production period has put forward higher requirements for improving production and efficiency in tight gas horizontal wells. Based on successful cases of tight gas reservoir fracturing both domestically and internationally, as well as the experience of unconventional reservoir volume transformation in the Qaidam Basin, this study conducts a historical analysis of reservoir characteristics and measures transformation in the Huangguamao block, evaluates the difficulties of measures transformation, optimizes the formation of two process ideas: high viscosity liquid controlled sand lifting fracturing and reverse composite fracture network fracturing, and prepares fracturing programme for MP2 and MP3 wells. After on-site fracturing, two processes were evaluated and analyzed, and the results showed that the reverse composite fracturing process, which takes into account both crack length and complexity, can effectively increase the transformation volume, provide more sufficient formation energy, increase production, and have stronger adaptability.