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Generators and condensers are the two vital equipment items that determine the output of vapor absorption refrigeration systems. Arid weather conditions produce a significant reduction in the performance of the vapor absorption refrigeration cycle due to low condenser heat dissipation despite high generator temperatures. Although numerous studies on condenser cooling methods in vapor compression systems have been reported in the literature, solar-operated vapor absorption systems have not been studied. Limitations in generator temperatures of solar-operated vapor absorption systems necessitate a focused study in this area. This study makes the selection of the best choice for condenser cooling from among four different condenser cooling methods which have an impact on the performance of the vapor absorption refrigeration system for effective cooling using solar energy. A solar vapor absorption refrigeration system working with low-grade heat using a compound parabolic collector is considered in this study. Analysis of a vapor absorption refrigeration system for cooling in arid weather conditions is carried out using different condenser cooling methods with Engineering Equation Solver. Initially, the model used in the study is compared with a similar study reported in the literature. Techniques considered are air, water, evaporative, and hybrid cooling techniques. The performance of the vapor absorption cooling system was analyzed using experimental values of a solar compound parabolic collector obtained from real-time measurements for simulating the model. Results show that water cooling can provide suitable condenser cooling and improve the coefficient of performance of the solar vapor absorption refrigeration system using the solar collector. The water-cooled condenser has 1.9%, 3.3%, and 2.1% higher COP when compared to air-cooled condensers for spring, summer, and autumn seasons respectively, whereas the water-cooled condenser cooling recorded 6%, 14%, and 8% higher COP relative to the evaporative cooling method. Cost comparison showed maximum cost for water-cooled condensers and minimum cost for hybrid-cooled condensers. The effect of each cooling method on the environment is discussed.

The ideal condenser with dielectric in general physics is delivered in a way that lacks in-depth explanation, leaving students in limbo when asked to explain how different surfaces on dielectric condensers when connected/disconnected with wires are charged. This paper will offer a relatively complete set of multiscale tutorials on different methods of applying Gauss’ law on condensers with a dielectric as well as a technique of abstracting condensers partially inserted with dielectric into parallel and series condenser models, both with an emphasis on how to better visualize different surfaces carrying charges of different origins. Special attention in this paper is paid to the best visualization to explain such concepts on different scales. This paper offers a relatively complete review and framework of ideal condensers with dielectric, 1 st proposed, which can serve as supplementary reading material for general physics learners and instructors for in-depth explanations or alternative perspectives on fundamental topics unavailable in textbooks.

The effect of a conventional round tube condenser and a Mini-channel condenser of a split-type air conditioner of 12,000 BTU/hr is compared in this paper in terms of geometrical parameters and performance parameters. In this present study, temperature and pressure were determined through experiments on both Mini-channel and round tube condensers with the same experimental setup, except for the condenser. These experimental data were used to calculate enthalpy, coefficient of performance (COP) and other parameters for the Mini-channel and round tube condensers. Data from both cases were compared. After comparison, it was found that the Mini-channel condenser has 11% higher COP than the round tube condenser, and it also requires 65.5% less refrigerant. Furthermore, the volume was reduced by 17.85%, and the frontal area was reduced by 44%. This means that the Mini-channel condenser will occupy less space than the round tube condenser. Therefore, it is suggested to use the Mini-channel condenser for the thermal management of the air conditioning system.

Passive solar membrane distillation (MD) is an emerging technology to alleviate water scarcity. Recently, its performance has been enhanced by multistage design, though the gains are marginal due to constrained temperature and vapor pressure gradients across the device. This makes condenser cooling enhancement a questionable choice. We argue that condenser heating could suppress the marginal effect of multistage solar MD by unlocking the moisture transport limit in all distillation stages. Here, we propose a stage temperature boosting (STB) concept that directs low-temperature heat to the condensers in the last stages, enhancing moisture transport across all stages. Through STB in the last two stages with a heat flux of 250 W m −2 , a stage-averaged distillation flux of 1.13 L m −2 h −1 S −1 was demonstrated using an 8-stage MD device under one-sun illumination. This represents an 88% enhancement over the state-of-the-art 10-stage solar MD devices. More notably, our analysis indicates that 16-stage STB-MD devices driven by solar energy and waste heat can effectively compete with existing photovoltaic reverse osmosis (PV-RO) systems, potentially elevating freshwater production with low-temperature heat sources. Multistage solar membrane distillation is facing challenges with current system designs due to constrained temperature and vapor pressure gradients. Here, the authors propose a stage temperature-boosting concept that enhances moisture transport with up to 88% improvement in overall distillate flux.

This study experimentally investigates axial fan pressure recovery in an A-frame forced draft heat exchanger configuration using a scaled isothermal test facility. Three different scaled axial fans were tested to determine pressure recovery coefficients by analysing the discrepancies between design (ignoring recovery) and measured air volume flow rates. The experimental findings confirm the presence of pressure recovery, with calculated recovery coefficients ranging from 0.293 to 0.427.

Steam condensers are vital components of thermal power plants, responsible for converting turbine exhaust steam back into water for reuse in the power generation cycle. Effective pressure regulation is crucial to ensure operational efficiency and equipment safety. However, conventional control strategies, such as PI, PI-PDn and FOPID controllers, often struggle to manage the nonlinearities and disturbances inherent in steam condenser systems. This paper introduces a novel multistage controller, TDn(1 + PIDn), optimized using the diligent crow search algorithm (DCSA). The proposed controller is specifically designed to address system nonlinearities, external disturbances, and the complexities of dynamic responses in steam condensers. Key contributions include the development of a flexible multi-stage control framework and its optimization via DCSA to achieve enhanced stability, faster response times, and reduced steady-state errors. Simulation results demonstrate that the TDn(1 + PIDn) controller outperforms conventional control strategies, including those tuned with advanced metaheuristic algorithms, in terms of settling time, overshoot, and integral of time weighted absolute error (ITAE). This study marks a significant advancement in pressure regulation strategies, providing a robust and adaptive solution for nonlinear industrial systems.

This paper introduces a novel cascaded softsign function-based PID (CSoft-PID) controller designed for precise pressure regulation in highly nonlinear shell-and-tube steam condenser systems. For the first time in the literature, the classical PID control structure is enhanced through a cascaded nonlinear transformation using the softsign function, which dynamically adjusts the controller input according to the magnitude of the error. This architecture allows for high sensitivity near the setpoint while gracefully limiting excessive control efforts during larger deviations, thereby improving stability and transient performance. To optimally tune the six parameters of the proposed controller, a new hybrid optimization algorithm, termed hGASO-PS, is proposed. This method synergistically integrates an adaptive gbest-guided atom search optimization (ASO) strategy with the precision of the pattern search (PS) technique, ensuring both effective global exploration and fine-tuned local exploitation. The controller parameters are optimized by minimizing the integral of time-weighted absolute error (ITAE), subject to a step change in the condenser pressure setpoint. Extensive simulations and statistical evaluations demonstrate the superiority of the proposed approach. The hGASO-PS-based CSoft-PID controller achieved the lowest ITAE value of 2.1608, with an average of 2.2746 across 30 runs. It also demonstrated the fastest settling time (12.51 s) and the lowest overshoot (1.98%) among all tested controllers. Comparisons with recent PI, FOPID, and cascaded PI-PDN controllers confirm the consistent outperformance of the proposed method in both transient response and control precision, making it a promising candidate for industrial condenser applications.

The efficiency and functionality of heating, ventilation, and air conditioning (HVAC) systems are critical to maintaining indoor air quality, comfort, and energy sustainability in residential, commercial, and industrial settings. With HVAC systems accounting for a significant portion of global energy consumption, the design of key components, particularly the condenser, is fundamental to achieving operational and environmental efficiency. This review explores the various types of condensers—evaporative, air-cooled, and water-cooled, and their impact on overall system performance. The advantages, limitations, and suitability of each type for different environmental conditions, along with optimization techniques to enhance efficiency, durability, and thermal performance, have become increasingly important. This study examined how recent advancements in condenser materials, microchannel technologies, and innovative configurations like variable-speed fans and smart controls contribute to enhanced system effectiveness. In addition, the paper highlights the role of computational modeling in refining the condenser design for reduced energy consumption and better heat exchange. The review underscores the need for continuous research and innovation to address the evolving challenges of climate change and energy regulations, ensuring that HVAC systems remain both sustainable and efficient. By considering the design, material selection, and cooling techniques, this paper provides a comprehensive overview of modern condenser design methodologies and suggests pathways for future development in HVAC technologies.

This paper theoretically and experimentally investigates the effect of condenser location and geometry on the thermal performance of a vapor chamber, as thermal management systems for electronic devices with multiple heat sources under non-uniform heat flux conditions. A weighting factor approach was applied to represent the non-uniform heat input imposed on individual heat sources. The proposed theoretical model was validated through comparison with Lefèvre’s analytical results under the same conditions and experimental data obtained under different condenser locations. It was shown that the wall temperature distribution for the separated condenser configuration was lower than for the concentrated configuration. Using the validated model, the effects of condenser geometry on the temperature uniformity and maximum heat transfer rate of the vapor chamber were analyzed under the capillary limit condition by varying the condenser aspect ratio. The results show that higher aspect ratios improve temperature uniformity due to wider condenser coverage, whereas lower aspect ratios enhance the maximum heat transfer rate by reducing the liquid pressure drop between the evaporator and condenser. Specifically, the maximum heat transfer rate reaches 72.6 W at an aspect ratio of 2.5, which corresponds to a 13.3% increase compared to 64.1 W at an aspect ratio of 8.3.

As a reactive power compensation device, fault diagnosis of synchronous condensers is of great significance for ensuring the stable operation of UHV DC transmission systems. Traditional fault diagnosis methods based on vibration signals have limitations, and existing signal decomposition methods also have their respective shortcomings. This paper proposes a wide-domain feature decomposition (WDFD) method, which first performs preliminary mode decomposition of signals according to spectral trends, then calculates the wide-domain feature indicator of each mode to quantify fault information in both time and frequency domains, and finally uses envelope demodulation for fault diagnosis. Verifications through simulated signal and experimental signal of synchronous condenser show that WDFD can effectively extract the modulation pulse characteristics in the fault signal of condenser. Compared with traditional methods, it can more accurately realize fault diagnosis of synchronous condensers under complex interferences, which provides a new effective approach for fault diagnosis of synchronous condensers.