Design of new heat pump dryer system: A case study in drying characteristics of kelp knots

Hu, Zicheng; Li, Yang; EL-Mesery, Hany S.; Yin, Dixi; Qin, Hao; Ge, Fenghua

doi:10.1016/j.csite.2022.101912

Cited by 16 publications

(6 citation statements)

References 38 publications

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“…In addition, due to the longer drying time and low drying rate at 30 °C, the energy consumption was relatively high. Hu et al [ 10 ] studied the HP of kelp knots. In contrast, the SMER of the proposed SHPD was 128.53% higher than that of the traditional system (1.630 kg/kW·h), indicating that the design can effectively improve the energy utilization rate and reduce energy consumption.…”

Section: Resultsmentioning

confidence: 99%

“…In the study, the ideal condition for kelp drying was a temperature of 40 °C, a wind speed of 1.3 m/s, and a humidity of 40%, without considering the heat pump system’s performance. Hu et al [ 10 ] examined a closed-loop double-evaporator heat pump dryer (HPD) used for kelp knots and found that the startup time of the instrument was 20.8% less than a conventional single-evaporator HPD, while its initial investment was only 6.5% more. However, the closed HP method faced serious problems caused by high relative humidity during kelp drying, which prolonged the drying time, increased the energy consumption and shortened the life of the instrument.…”

Section: Introductionmentioning

confidence: 99%

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Design of a Greenhouse Solar-Assisted Heat Pump Dryer for Kelp (Laminaria japonica): System Performance and Drying Kinetics

Kang

Zhang

et al. 2022

Foods

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In order to solve a series of problems with kelp drying including long drying time, high energy consumption, low drying efficiency, and poor quality of dried kelp, this work proposes the design of a novel greenhouse double-evaporator solar-assisted heat pump drying system. Experiments on kelp solar-assisted heat pump drying (S−HP) and heat pump drying (HP) under the condition of irradiance of 100−700 W/m2 and a temperature of 30, 40, or 50 °C were conducted and their results were compared in terms of system performance, drying kinetics, and quality impact. The drying time was reduced with increasing irradiance or temperature. The coefficient of performance (COP) and specific moisture extraction rate (SMER) of S−HP were 3.590−6.810, and 1.660−3.725 kg/kW·h, respectively, roughly double those of HP when the temperatures are identical. The Deff of S-HP and HP were 5.431 × 10−11~11.316 × 10−11 m2/s, and 1.037 × 10−11~1.432 × 10−11 m2/s, respectively; additionally, solar radiation greatly improves Deff. The Page model almost perfectly described the changes in the moisture ratio of kelp by S−HP and HP with an inaccuracy of less than 5%. When the temperature was 40 °C and the irradiance was above 400 W/m2, the drying time of S−HP was only 3 h, and the dried kelp maintained the green color with a strong flavor and richness in mannitol. Meanwhile, the coefficient of performance was 6.810, the specific moisture extraction rate was 3.725 kg/kWh, and the energy consumption was 45.2%, lower than that of HP. It can be concluded that S−HP is highly efficient and energy-saving for macroalgae drying and can serve as an alternate technique for the drying of other aquatic products.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Design of a Greenhouse Solar-Assisted Heat Pump Dryer for Kelp (Laminaria japonica): System Performance and Drying Kinetics

Kang

Zhang

et al. 2022

Foods

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“…Thin-layer models estimate mass transfer while drying and are used for simulating drying curves at identical settings (Puente-Díaz et al, 2013). According to Hu et al (2022), mathematical modeling is the best way to characterize the drying procedure's kinetics. The design and modeling of several mass transfer methods, with the adsorption, dehydration, and desorption of moisture throughout storage, can benefit from optimal moisture diffusivity.…”

Section: Introductionmentioning

confidence: 99%

Mathematical modeling of thin‐layer drying kinetics and moisture diffusivity study of apple slices using infrared conveyor‐belt dryer

El‐Mesery,

Ashiagbor,

et al. 2024

Journal of Food Science

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The drying features of apples at different infrared drying settings were investigated. The drying time, moisture‐effective diffusion, and activation energy of infrared dried apples were measured experimentally and statistically as a function of slice thicknesses, radiation intensity, and air velocity. The infrared intensity of 0.225, 0.130, and 0.341 W/cm2, slice thicknesses of 6, 4, and 2 mm, and airflow of 0.5, 1.0, and 1.5 m/s were used to dry apple slices. The data shows that the drying time reduced as IR increased, but airflow and slice thickness increased. Eight statistical factors were used to compare 11 alternative mathematical drying models. The experimentally acquired drying curves were matched to the thin‐layer drying equations. According to the calculations, the Midilli et al. equation had the greatest (efficiency and R2) and lowest (χ2, sum of squared errors, standard error of estimate, standard error, standard deviation of difference) values. As a result, this equation is the best for modeling the drying curves of apple slices across all drying circumstances. The optimum moisture diffusivity value varied from 2.59 to 9.07 × 10−10 m2/s. The mean activation energy was determined to be 19.02–29.83 kJ/mol under various experimental conditions.

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“…Thin layer models estimate mass movement while drying and are exhausted for simulating drying curves under identical conditions (Puente-Díaz et al, 2013). According to Hu et al (2022), mathematical modeling is the greatest technique to describe the dehydrating procedure's kinetics. The design and modeling of several mass transfer processes, including the adsorption, dehydration, and desorption of moisture throughout storage, can benefit from optimal moisture diffusivity.…”

Section: Introductionmentioning

confidence: 99%

“…According to Hu et al. (2022), mathematical modeling is the greatest technique to describe the dehydrating procedure's kinetics. The design and modeling of several mass transfer processes, including the adsorption, dehydration, and desorption of moisture throughout storage, can benefit from optimal moisture diffusivity.…”

Section: Introductionmentioning

confidence: 99%

A study into how thickness, infrared intensity, and airflow affect drying kinetics, modeling, activation energy, and quality attributes of apple slices using infrared dryer

El‐Mesery,

Hu,

Ashiagbor

et al. 2024

Journal of Food Science

Self Cite

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Drying is a widely recognized process that reduces the need for storage and shipping weight, keeps free water out of the product, and prolongs its shelf life. An infrared dryer was designed to dry apples under different drying conditions. Apple slices of 6‐, 4‐, and 2‐mm thicknesses were dried at intensities 0.130, 0.225, and 0.341 W/cm2 and airflow 1.0, 0.5, and 1.5 m/s. The dehydrating period was prolonged with higher airflow and shortened with higher infrared intensity (IR). The shortest dehydrating period was verified by 190 min at 0.341 W/cm2, 0.5 m/s under 2 mm thickness. Increasing the sample thickness from 2 to 4 mm and then to 6 mm resulted in an 84% and 192% increase in drying time, respectively. Dehydrated apples had water activity values ranging from 0.30 to 0.40. The shrinkage ratio increased with an increase in infrared radiation intensity. However, it decreased with an increase in air velocity, while the rehydration ratio decreased with an increase in radiation intensity and increased with an increase in air velocity. Regarding total color change, apple slice thickness was a major factor. The effective diffusivities varied between 2.6 and 9.0 𝗑10−10 m2/s under different drying conditions. The dehydrating curves of apples were best described by the model developed by Midilli et al.

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Design of new heat pump dryer system: A case study in drying characteristics of kelp knots

Cited by 16 publications

References 38 publications

Design of a Greenhouse Solar-Assisted Heat Pump Dryer for Kelp (Laminaria japonica): System Performance and Drying Kinetics

Design of a Greenhouse Solar-Assisted Heat Pump Dryer for Kelp (Laminaria japonica): System Performance and Drying Kinetics

Mathematical modeling of thin‐layer drying kinetics and moisture diffusivity study of apple slices using infrared conveyor‐belt dryer

A study into how thickness, infrared intensity, and airflow affect drying kinetics, modeling, activation energy, and quality attributes of apple slices using infrared dryer

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