Energy Wheel Research Articles

Importance of NADIS (Channels) and CHAKRAS (Energy Wheel) for Energy Healing

Importance of NADIS (Channels) and CHAKRAS (Energy Wheel) for Energy Healing

A dual-kinetic energy harvester operating on the track and wheel of rail deceleration system for self-powered sensors

Alternative energy sources play a crucial role in Outback rail systems, where electrical infrastructure is unavailable for automated power devices used for traffic lights, surveillance cameras, sensors, and other safety equipment at railway stations and intersections. The current study proposes an innovative dual-kinetic energy harvester design to reduce train speed at intersections and before it comes to a halt at the station. Additionally, it harvests energy from both the train track and wheel simultaneously. The proposed device consists of three main units. The first unit utilizes vibrational movement based on a rack pinion. An efficient dual-kinetic energy harvesting system has been developed, utilizing a novel concept that captures the vibration energy generated by the movement of the rail under the influence of the train’s weight. Additionally, as the train passes at high speed, the train wheel’s energy will be transmitted to the top of the device, moving the rack to a depth of 30 mm. A spiral spring is employed to restore the rack to its initial position after the wheel has passed. The tension force of the spring causes the rack to adhere to the track, enabling the transmission of vibrations generated by the track’s movement and releasing energy, causing the motion to be induced during the return stroke. The second component is the transmission unit. The bidirectional rotational motion from the rack pinion is converted into unidirectional rotational motion using three bevel gears, two roller clutches, and a planetary gearbox to enhance the rotations of the generator shaft. The third component is a 1500 W/180 V DC motor for electricity generation. Lastly, the charging circuit was developed to recharge supercharged capacitors. The proposed system was installed before the railway station, and practical tests were conducted, which showed an efficiency of up to 55%.

Unleashing wastewater heat Recovery's potential in smart building systems: Grey wolf-assisted optimization aided by artificial neural networks

This article presents an innovative and efficient way to address residential dwellings' substantial heating needs. The primary objective is to utilize the heat from wastewater to enhance energy efficiency through a control framework based on predetermined rules. This framework aims to increase the incoming air temperature at the air handling unit. A thorough evaluation is carried out to analyze all aspects of the proposed system compared to an identical system that does not incorporate the wastewater heat recovery process. The practicality of the concept is assessed for a residential building located in Beijing, China, employing the TRNSYS software. The most optimal operating condition is achieved via the grey wolf optimizer and TOPSIS decision-making approach equipped with the artificial neural network using MATLAB. Then, the proposed system's performance under optimal conditions is compared with similar works in the literature. According to the results, compared to the conventional system, a higher performance efficiency of 6 % and lower levelized cost of heating of 15.6 $/MWh is obtained by implementing the wastewater heat recovery process. The parametric study results also demonstrate a conflicting change in techno-economic and environmental indicators when altering the primary decision variables, highlighting the necessity for multi-criteria optimization. What stands out from the optimization outcomes is that the grey wolf method increases the efficiency and CO2 saving by around 5.2 and 531.2 kg/year while reducing the levelized cost of heating by about 13.6 $/MWh, respectively. The optimization results reveal that this condition is attained by raising the heat exchanger's effectiveness and the number of residences and decreasing the wastewater temperature. According to the scatter distribution of key parameters, the energy wheel effectiveness has low sensitivity, and the optimal points of tank volume are distributed within the range of 3 m3 and 4 m3.

Experiment and Prediction of Pressure Drop in a Fiber–Powder Composite Material with Porous Structure for Energy Wheels and Air Cleaners

Energy wheels and air cleaners play crucial roles in building air conditioning systems. The former is essential for conserving energy in air conditioning systems, while the latter is necessary for ensuring the quality of indoor air. Pressure drop is a crucial parameter for both energy wheels and air cleaners, and it is essential to conduct theoretical and experimental investigations to aid in their design. In this study, we focused on the study of pressure drop in a fiber–powder composite material which can be used for both total heat exchange and air purification. Experimental tests were initially conducted to examine the impact of different parameters on the pressure drop in the material. Subsequently, based on the special fiber–powder structure of the material, two pressure drop prediction methods with different prediction strategies were proposed. The two prediction strategies were compared by analyzing the prediction accuracy of the two methods. As tested by experimental data, for both methods, the absolute prediction error was less than ±6 Pa when the pressure drop was below 50 Pa, and the relative prediction error was less than ±8% for most data sets when the pressure drop was greater than 50 Pa. Moreover, the root mean square error (RMSE) and mean absolute percentage error (MAPE) values of prediction for both methods were less than 4 Pa and 7% respectively. The test results show that although the prediction strategies are different, both prediction methods can obtain acceptable prediction results, and both methods are practical. This study is intended to serve as a valuable reference for the design of energy wheels and air cleaners.

Pembuatan Alat Peraga Roda Energi Guna Mempermudah Proses Pembelajaran IPA Terpadu

The Integrated Science Props Energy Wheel is used as a tool to help students understand the conversion of motion energy into electrical energy and gain knowledge about the processes of catabolism and anabolism in cellular metabolism within the human body. Additionally, this tool presents a visually engaging, challenging, and enjoyable representation of the differences between molecules and compounds, aiming to attract students to study Natural Sciences. The research objective is to determine the design and working principles of the integrated energy wheel teaching aid. The research method employed is experimental method with a descriptive approach., involving the collection of data through detailed narratives and direct observation of the object under study. The study results in the creation of the integrated science props Energy Wheel, which has dimensions of 25 cm in length, 25 cm in width, and 20 cm in height. In this Energy Wheel, the conversion of motion energy into electricity is indicated by the illumination of lights mounted on the props when the wheel is turned. The illuminated lights symbolize the bond formation between simple molecules to form complex molecules, representing an anabolism reaction. When the wheel stops turning, the lights turn off, signifying the return of complex molecules to simple molecules and the occurrence of a catabolism reaction.

Validation of Extrapolation of Test Performance for Air-to-Air Rotary Energy Exchangers (ASHRAE RP-1799)

Air-to-air energy exchangers are used in buildings to transfer energy between the exhaust air and the incoming outdoor air. Typically, the performance of air-to-air energy exchangers is tested, rated and certified according to industry-accepted standards and procedures. Because of the expenses and facility constraints associated with laboratory testing, performance rating tests of air-to-air energy exchangers are usually performed at a limited number of test conditions for selected products. This paper uses laboratory tests to validate the extrapolation approaches available from the literature. Two sets of air-to-air energy wheels from different manufacturers were tested at the energy recovery testing facility of Intertek. Each set included three wheels of different sizes (i.e., small, medium, and large). The analysis of test results showed an overlap in performance ratings between different wheel sizes after accounting for allowable allowances, which in turn supported the extrapolation approach used by the Air-Conditioning, Heating, and Refrigeration Institute for performance rating. By comparing the test results with the results from the selected effective correlations, it was found that axial heat conduction should be considered when applying the numerical heat and mass transfer models for energy wheels.

Experimental study of a LiCl-modified fibrous core material for energy wheels

In this study, an experimental investigation is presented of a core material with irregular-shaped air flow channels for energy wheel applications. An experimental setup is established to test the performance of the material and study and analyze its characteristics. The core material has polyester wadding as the matrix and is sprayed with activated carbon as a hygroscopic material. Pores are found in the hygroscopic material attached to the fiber which contribute to the improvement of the heat exchange area between air and the material. To improve the performance of the material, it is modified by a lithium chloride solution. The test results showed that by implementing the lithium chloride modification, the hygroscopic capacity of the material can be significantly enhanced. The material latent and enthalpy efficiencies can be improved by about 10 % and 20 % at 0.5 rpm rotational speed with the action of lithium chloride at 2 % and 6 % mass concentration respectively. In addition, the efficiencies of the test material can be improved by more than 10 % by increasing its length from 38 mm to 50 mm. It is shown that the increase in the air flow rate leads to a decrease in the latent and enthalpy efficiencies. Mathematical models are used to analyze the latent efficiency of the material. Results showed that the efficiency of the modified material improved substantially at both high rotational speeds (>10 rpm) and low rotational speeds (0–10 rpm). Overall, the proposed core material offers an alternative low-cost and compact choice for energy wheel applications in air conditioning systems. The current study provides a preliminary assessment of such material and is aimed at establishing a better understanding of the promising potential in energy wheel applications.

Suitability of bio-desiccants for energy wheels in HVAC applications

This paper investigates the suitability of bio-desiccants for moisture recovery in energy wheels. Bio-desiccants are environment-friendly materials that have high water vapor adsorption capacities. The main contribution of this paper is that it reports the latent effectiveness of flax-fiber (bio-desiccant) coated energy wheels for a wide range of operating conditions and compares the effectiveness of the flax-fiber wheels with wheels that are coated with commercially available desiccants and other biomaterials. The moisture transfer performance of a flax-fiber coated exchanger is determined using a small-scale test facility and two different experimental methods: single step change tests and cyclic tests. The test results are used to verify the applicability of an effectiveness correlation from the literature. Using the energy wheel correlation and the sorption isotherms, the latent effectiveness of commercially available energy wheels coated with molecular sieve, ion exchange resin and silica gel desiccants are obtained and compared with that of bio-desiccants (flax fiber and starch particles). The highest latent effectiveness is obtained for silica gel followed by starch particles, ion exchange resin, flax-fiber and molecular sieve. The results from this study will be useful in research and development of bio-materials for energy recovery systems for building applications.

Semi-empirical mapping method for energy recovery wheel performance simulation

Abstract Energy recovery ventilators are often employed in buildings to decrease the energy consumed by their HVAC systems, and to improve overall indoor air quality. Several studies in the open literature have developed physical or empirical models to simulate the performance of energy recovery wheels. However, these models are often computationally intensive, time-consuming, or require numerous experimental data points to train and execute the performance predictions. These models also tend to lack flexibility for varying all of the available wheel design parameters. Hence, developing a mapping method with better computational efficiency and flexibility is the goal of this research. A finite difference numerical model for simulating the performance of an energy wheel has been developed and validated using experimental test results from independent laboratories. This model was then employed to provide an extensive data set for the development of an energy wheel performance mapping method. After validating this new mapping approach, the method predictions were compared against independent data sets from two different laboratories, and additional sources available in the literature, to identify its universality. The mapping method delivers good agreement between the predictions and validation data, and requires only a small number of data points to train, which is one of its novel contributions. Another unique contribution of the proposed mapping method is that once the model is trained it can predict the performance characteristics for other wheels with different physical design geometries and operating conditions, provided only that the desiccant material is the same.

Simulation of the Performance of Solar Driven Thermoelectric Based Rotary Desiccant Wheel HVAC System

<div class="section abstract"><div class="htmlview paragraph">In the automotive applications, the main functionality of the HVAC system includes heating, ventilation, and cooling or air-conditioning of the vehicle to achieve the desired indoor thermal comfort. In the current scenario, the conventional vapor compression based HVAC system is widely used. The typical refrigerants used to operate this equipment include HFCs and HFOs which are susceptible to cause an environmental hazard. This article aims to assess the performance of a hypothetical solar-driven thermoelectric based rotary desiccant wheel HVAC system (D-HVAC) to be used for automotive applications. The D-HVAC system uses the desiccant wheel to remove the latent heat, energy wheel to remove the sensible heat, evaporating coolers to achieve further cooling, the regeneration of the desiccant wheel by hot air and water as the refrigerant. In the case of a solar-driven-DHVAC system, solar energy is utilized for the regeneration of the desiccant wheel in place of hot air. However, the intensity of incident solar energy varies throughout the day. To compensate for this energy fluctuation an additional thermoelectric system (Peltier device) can be added to achieve the optimum regeneration of the desiccant wheel. The Peltier device avails the advantage to simultaneously heat the regeneration air and cool the process air to achieve the highest cooling coefficient of performance (COP) of the solar-driven D-HVAC system. The usage of PV cells to produce the required electricity to operate the blowers (for process air and regeneration air) and motor of the rotary desiccant wheel and TEC. Overall, through numerical simulation, the increment in the COP of the solar-driven thermoelectric based rotary desiccant wheel HVAC system in comparison with the simple D-HVAC system and conventional vapor compression based HVAC system are investigated.</div></div>

Performance study of a novel dew point evaporative cooler in the climate of central Europe using building simulation tools

This paper presents the performance research of a hybrid air conditioning system (System II) equipped with novel dew point evaporative cooler (DPIEC) for a retail building located in temperate climatic conditions. The new cooler has a dedicated, adaptable structure that maximizes its performance in the climate conditions of central Europe. The unit can operate as a typical regenerative air cooler when outdoor air is drier than indoor air, it can operate as a counter-flow heat recovery unit when indoor conditions are more dry than outdoor and it can operate as a combination of both arrangements. The year-round, hourly-stepped building energy simulations were carried-out using a prognostic tool of energy consumption. The novel dew point evaporative cooler application potential was established using the black-box model based on regression equations was established based on experimental tests on a prototype of novel DPIEC. The hybrid system operation was compared to the typical air handling unit equipped with a standard energy wheel for heat recovery (System I). Presented research shows that DPIEC can cover about 95% of total cooling loads while the energy wheel covers only 9% of total cooling load. System II allows us to save 65% of seasonal electricity consumption comparing to System I. It comes from the fact that during most of the cooling season DPIEC is in operation and it covers most of the cooling loads without the need to switch the chilled water system.

Comparison of the Moisture Adsorption Properties of Starch Particles and Flax Fiber Coatings for Energy Wheel Applications.

The adsorption–desorption behavior of flax fibers (FFs) is reported in this paper. FFs are a potential desiccant material for air-to-air energy wheels, which transfer heat and moisture in building heating, ventilation, and air conditioning (HVAC) systems. The raw FFs sample was subjected to physical modification, followed by complementary material characterization to understand the relationship between its structure and its moisture uptake performance. The surface and textural properties of the modified FFs were determined by gas adsorption (N2, H2O) and gravimetric liquid water swelling studies and further supported by spectroscopic (infrared and scanning electron microscopy) results. A FF-coated small-scale energy exchanger was used to determine the moisture transfer (or latent effectiveness; εl) using single-step and cyclic testing. The FF-coated exchanger had εl values of ∼10 and 40% greater compared to similar exchangers coated with starch particles (SPs) and silica gel (SG) reported in a previous study. The enhanced surface and textural properties, along with the complex compositional structure of FFs and its greater propensity to swell in water, account for the improved performance over SPs. Thus, FFs offer an alternative low-cost, environment-friendly, and sustainable biodesiccant for air-to-air energy wheel applications in buildings. The current study contributes to an improved understanding of the structure–function relationship of biodesiccants for such energy wheel applications.

Water Vapor Adsorption-Desorption Behavior of Surfactant-Coated Starch Particles for Commercial Energy Wheels.

This study reports on the adsorption (dehumidification)–desorption (humidification) behavior of cetylpyridinium bromide (CPB) coated starch particles (SPs), denoted as SP-CPB, as a potential desiccant material for air-to-air energy exchangers. CPB is a cationic surfactant with antibacterial activity that can be used to modify the surface properties of SPs, especially at variable CPB loading levels (SP-CPB0.5, SP-CPB2.5, and SP-CPB5.0, where the numeric suffix represents the synthetic loading level of CPB in mM). The SP-CPB0.5 sample displayed optimal surface area and pore structure properties that was selected for water sorption isotherm studies at 25 °C. The CPB-coated SPs sample (SP-CPB0.5) showed an improved water vapor uptake capacity compared to unmodified starch (SPs) and other desiccant systems such as high amylose starch (HAS15) and silica gel (SG13). Single-step and cyclic water vapor sorption tests were conducted using a small-scale exchanger coated with SP-CPB0.5. The calculated latent effectiveness values obtained from direct measurements using cyclic tests (65.4 ± 2%) agree closely with the estimated latent effectiveness from single-step tests (64.6 ± 2%) at controlled operating conditions. Compared to HAS15- and SG13-coated exchangers, the SP-CPB0.5-coated exchanger performed much better at controlled operating conditions, along with improved longevity due to the CPB surface coating. The presence of CPB did not attenuate the uptake properties of native SPs. Latent effectiveness of SP-CPB0.5-coated exchanger was enhanced (5–30% higher) over that of the SG13- or HAS15-coated exchangers, according to the wheel angular speed. This study reports on a novel and sustainable SP-CPB0.5 material as a promising desiccant coating with tunable uptake and surface properties with potential utility in air-to-air energy exchangers for ventilation systems.

Experimental investigation on operation parameters of 3Å molecular sieve desiccant coated total energy recovery wheel for maximum effectiveness

The object of this research study was to investigate the maximum effectiveness values of the energy wheel by experimental tests conducted under extreme difference ambient air conditions parameters, different air volume flow rates, and energy wheel rotation speeds. Air temperature and humidity experimental tests were performed using a test facility that was developed and installed into the Indoor Air Quality and Thermal Comfort Laboratory of Budapest University of Technology and Economics. Our objective was to get the effectiveness values of sorption coated air-to-air energy recovery wheel for steady-state conditions under different ambient air (as supply air inlet) conditions. It was found that the sensible effectiveness increases by decreasing the volumetric flow rate through the wheel, and the optimum values of the effectiveness were given at the maximum wheel rotation speed based on the tests. As for the latent and total effectivenesses, their characteristics show an increasing trend by decreasing the air volume flow rate, ambient air temperature and relative humidity and increasing the wheel rotation speed.

Experimental investigation of carbon dioxide cross-contamination in sorption energy recovery wheel in ventilation system

The aim of this research was to investigate the scale of carbon dioxide recirculation in rotary energy wheel operated in air handling units. To achieve this objective, a test facility was installed into the indoor air quality and thermal comfort laboratory of BUTE University. A newly developed molecular 3 Å sieve sorption wheel with high humidity transfer efficiencies is integrated into the experimental setup. In this research study, carbon dioxide cross-contamination rate from the exhaust side into the supply side in sorption regenerative air-to-air rotary energy exchanger was conducted by experimental tests. During the study, the correlation between the carbon dioxide cross-contamination, different rotational speeds of the wheel and different volume flow rates of supply air were also investigated in detail. Based on the results, a rotation speed diagram – carbon dioxide cross-contamination diagram – is plotted which can be very useful for researchers, developers and building service engineers in practice. Practical application: The most perfect energy exchanger can transfer both heat and moisture, thus providing a pleasant indoor air quality in the conditioned space. It is beneficial if the exchanger can transfer heat and moisture between the supply and exhaust airstreams, thereby minimizing the capacity and energy consumption of the required auxiliary heater and humidifier. The auxiliary energy reduction can be especially high if the sorption material of the energy wheel is of type 3 Å molecular sieve that has an extremely high humidity transfer capacity. The disadvantage of the rotary energy recovery is the cross-contamination from the exhaust air to the supply air. This is very important because in places such as offices, schools, public institutions, carbon dioxide cross-contamination can cause degradation of indoor air quality.

Novel air conditioning system configuration combining sensible and desiccant enthalpy wheels

There is a great importance of studying various solutions to reduce energy consumption. The energy consumption in the air conditioning systems became remarkable in the recent years. This paper addresses a retrofit for improving the thermal performance of air conditioning systems in buildings with large energy consumption. Intensive care units in hospitals are one of the most energy consumption units due to all fresh air utilization. An existing hospital building was used for this study, targeting the retrofit of air conditioning system having 100% fresh air for the intensive care unit (ICU). In the proposed new system, an arrangement of two energy wheels is studied for the first time to retrofit existing system through exhaust air energy recovery. Simulation model has been developed on the basis of the building energy simulation program (EnergyPlus). An hourly simulation has been performed for an entire year and the proposed retrofit air conditioning system was found to be more energy efficient. The results show a significant decrease in the cooling coil capacity with zero heating load capacity and hence a saving in power consumption up to 87.15% in winter (February) and lowest saving of 13.53% in summer (August).

Effects of Physical and Sorption Properties of Desiccant Coating on Performance of Energy Wheels

Desiccant-coated energy wheels are rotary-air-to-air energy exchangers widely used in ventilation systems to reduce the energy consumption required in industrial environments and commercial buildings. In this study, the effects of silica gel microphysical properties, i.e., pore width (Pw), specific surface area (SA), and particle size (dp), on the moisture recovery efficiency (latent effectiveness) of energy wheels are investigated. Three silica gel samples with different particle size and pore width (55 μm–77 Å, 150 μm–63 Å, and 160 μm–115 Å) are selected to coat small-scale energy exchangers. The sorption performance of the exchangers is determined from their normalized humidity response to a step increase in the inlet humidity at different flow rates. The results demonstrate that the transient humidity response is mainly specified by the desiccant pore size distribution, specific surface area, and mass of the coating. The transient analytical model is used to calculate the latent effectiveness (ɛL) of the exchangers from the transient humidity response. It was found that the exchanger coated with the smallest pore width (63 Å) has the highest available surface area and the highest latent effectiveness. With almost the same particle size (dp = 150 μm and 160 μm), the latent effectiveness increases by 5% (at wheel speed 20 rpm and Re = 174) as the pore width reduces from 150 Å to 63 Å. Increasing the particle size from 55 μm to 150 μm with almost the identical pore width (Pw = 63 Å and 77 Å) results in a slight enhancement in the latent effectiveness. ɛL is also calculated for correlated data (Yoon–Nelson model) where the results agree within experimental uncertainty bounds.

Study of Dehumidification and Regeneration in a Starch Coated Energy Wheel

Energy wheels were designed using desiccant-coated materials to exchange energy between supply and exhaust air streams to reduce the energy required to condition ventilation air. Recent advances in energy wheel design that use biopolymer desiccant materials have provided the motivation in this paper to investigate the performance of starch coated energy exchangers. A small-scale high amylose starch (HAS) coated exchanger was built, and its transient response to a step change in inlet humidity was acquired and studied at conditions of variable air flow rate and temperature. The humidity response, dehumidification, regeneration capacity, and the rate of moisture removal were measured. The results demonstrate that greater regeneration flow rate and temperature can enhance the regeneration capacity. In spite of the increase in the regeneration capacity, the moisture recovery (latent) effectiveness decreased as the air flow rate and/or temperature increased. The effectiveness is reduced by 15% when the flow ra...

Sorption Study of a Starch Biopolymer as an Alternative Desiccant for Energy Wheels

The sorption of water vapor on high amylose starch was investigated as an alternative desiccant for air-to-air energy exchangers used in ventilation units. Sorption performance of micron-sized mesoporous high amylose starch (HAS15, dp = 15 μm, Pw = 46 A) and two mesoporous silica gel samples (SG13, dp = 13 μm, Pw = 62 A; Pw = 62 A; SG55, dp = 55 μm, Pw = 77 A) were studied and compared. Transient water vapor sorption tests were performed using small-scale energy exchangers coated with HAS15 and silica gel. Although N2 gas adsorption tests showed lower sorption capacity for HAS15 compared to the silica gel samples, higher sorption rates and uptake capacity were shown for HAS15 when measured by water vapor transient sorption results. In addition, the latent effectiveness, an indicator of moisture recovery efficiency for exchangers, was calculated for each exchanger. With the same amount of desiccant coated on the energy exchanger channels, the latent effectiveness of the HAS-coated material was 2%–13% great...

Heat Transfer in a Recovery Energy Wheel

Integrating energy (heat and moister) recovery ventilator and heat recovery ventilator has gained more attention recently as far as ventilation requirements and energy saving are concerned. In this paper, the selected ventilator employs rotary air-to-air energy wheel with a porous matrix under a medium of heat transfer. Such an energy wheel can operate with high effectiveness by using a low-cost porous matrix energy core. In order to determine the effectiveness of the energy wheel, a mathematical and numerical simulation model has been developed for a symmetrical and balanced wheel operating in a counter-flow arrangement. This sensible model is used for the examination of the effectiveness of the wheels during summer and winter. The effects of operating parameters such as rotational speed, gas velocity and volume flow rate on the performance of the process have been studied and compared with the available results of the literature