Thermal conditions of Adsorptive heat storage device operating in open-mode for  heating inflowing air

Thermal conditions of adsorptive heat storage device operating in open-mode were considered when discharged. The main operating parameters affecting the final temperature of airflow which supplied to ventilated premises are determined on the example of heat storage device based on composite ‘silica gel – sodium sulphate’. The main factors which determine a final airflow temperature are confirmed to be initial values of temperature, absolute humidity and speed of airflow which fanned to the adsorbent layer. Algorithm of calculating the operational parameters of adsorptive heat storage device has been further developed. Proposed algorithm involves calculation of diffusion coefficient, mass transfer coefficient, final absolute humidity of airflow, volume of air which passed through adsorbent layer, adsorption, specific adsorption heat and final airflow temperature, then useful heat, heat inputs for operating heat storage device and its efficiency factor are estimated. The adequacy of the proposed algorithm has been confirmed according with experimental data for operating of open mode adsorptive heat storage device. Curves final temperature of inflowing air vs. time of discharge of heat storage device are stated to depend on characteristics of airflow which fanned to the adsorbent layer such as temperature, speed and initial absolute humidity. When these parameters increased, time to achieve plateau, i.e. maximal values of final inflowing air temperature decrease. The dependence of initial values of temperature, absolute humidity, speed of humid airflow and final airflow temperature is shown. Maximal temperatures of at most 65 – 80 ºC are stated at the initial temperatures and absolute humidity of initial airflow within the ranges of 20 – 30 ºC and 0.03 – 0.04 kg/m3, respectively. The results of the present study can be used for the development of energy-efficient systems and devices for air-conditioning in habitual inner space and warehouses.

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Performance of Adsorptive Heat Storage Devices for Heat Supply

Technology Development for Adsorptive Heat Energy Converters - Advances in Chemical and Materials Engineering ◽

10.4018/978-1-7998-4432-7.ch005 ◽

2021 ◽

pp. 124-173

Keyword(s):

Silica Gel ◽

Heat Supply ◽

Heat Storage ◽

Sodium Sulphate ◽

Storage Device ◽

Efficiency Coefficient ◽

Composite Adsorbent ◽

Open Type ◽

Storage Devices ◽

Closed Type

The chapter is focused on modelling of performance of adsorptive heat storage devices and estimation of performance of heat storage devices. Two groups of models of adsorptive heat storage units suggested previous researchers are analyzed. The first one is focused on predicting the heat energy storage density, it being based on Dubinin-Polanyi theory. The second one is devoted to analyzing the kinetic of adsorption processes and performance of the adsorber or adsorptive-desorptive reactor filled with traditional adsorbent or salt which forms crystalline hydrates. The key drawback of both groups of models concerns with considering only one stage of exploitation of adsorptive heat storage device in spite of its operating in two-stage mode, that is, alternating discharge (adsorption) and charge (regeneration). It inhibits estimation of efficiency of adsorptive heat storage device basing on full operating cycle and its involving in heat supply system. Two algorithms for estimation of operating parameters are proposed by authors for closed-type and open-type heat storage devices. The algorithm for calculation of operating parameters of closed type adsorptive heat storage device is proposed: calculation of the mass transfer coefficient, adsorption, useful heat, that is, heat of adsorption, determination of the heat input, it being calculated as heat inputs for heating the adsorbent, device housing, water in the tank, evaporation of water in the tank, heating of the adsorbed water and desorption. Then efficiency factor is calculated. The operating characteristics of a closed-type heat energy storage device were studied when the composite adsorbent ‘silica gel – sodium sulphate' used. The effect of the humid airflow velocity on the efficiency factor is taken into account by introducing a coefficient equal to the value of the adsorption. An increase in the efficiency coefficient was stated when the velocity and relative humidity of the airflow. It is shown that the humid air flow temperature practically does not affect its value. Having been used the suggested algorithm, the optimal operating characteristics of an adsorptive heat storage device of a closed type based on a composite adsorbent ‘silica gel – sodium sulphate' for a private house heating system are revealed to be humid air velocities of 0.6 – 0.8 m/s and relative humidity 40 – 60%. When these operational data applied, the efficiency coefficient is shown to reach the maximum values (about 55%). Algorithm of calculation of operating parameter of open-type heat storage device includes computation of mass transfer coefficient, adsorption, useful heat (heat of adsorption), heat input for heating the adsorbent, device casing, water in the humidifier, evaporation of water, heating the adsorbed water, desorption, and calculating efficiency coefficient. Performance of open-type heat storage device based on the composite adsorbent ‘silica gel – sodium sulphate' is estimated. The optimal operating conditions of the heat accumulating device which allow operating with maximal magnitudes of efficiency coefficients 53 – 57% are stated to be humid airflow speed of 0.6 – 0.8 m/s and relative humidity of 40 – 60%. Correlation between efficiency factors obtained by experiments and calculated with suggested algorithm is confirmed. The possibility of reducing the power consumption when heat storage devices applied in 2,4 – 90 times versus decentralized heating systems on basis of solid fuel boiler, gas boiler and electric boiler is stated when open-type sorptive heat storage device used. Results of the study can be used to develop adsorptive storage devices in decentralized heat supply and ventilation systems and adsorption units for utilization of low-temperature waste heat.

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Energy efficient operational processes of adsorptive heat storage device based on composite “silica gel – sodium sulphate”

Collection of Scientific Publications NUS ◽

10.15589/znp2019.3(477).4 ◽

2019 ◽

Vol 3(477) ◽

pp. 27-34

Author(s):

Olena A. Bielianovska ◽

Roman D. Lytovchenko ◽

Kostiantyn M. Sukhyi ◽

Anton E. Buzov ◽

Mykhailo P. Sukhyi

Keyword(s):

Silica Gel ◽

Energy Efficient ◽

Heat Storage ◽

Sodium Sulphate ◽

Storage Device ◽

Operational Processes

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Performance of adsorptive heat-moisture regenerator

Scientific Works ◽

10.15673/swonaft.v84i1.1877 ◽

2020 ◽

Vol 84 (1) ◽

pp. 98-103

Author(s):

Elena Belyanovskaya ◽

Roman Lytovchenko ◽

Kostyantyn Sukhyy ◽

Mikhaylo Sukhyy ◽

Mykhailo Gubynskyi ◽

...

Keyword(s):

Mathematical Model ◽

Silica Gel ◽

Air Temperature ◽

Ventilation System ◽

Absolute Humidity ◽

Sodium Sulphate ◽

Adsorbent Layer ◽

Services Sector ◽

Calculation Results ◽

The Mathematical Model

The performance of the adsorptive heat-moisture regenerators based on the composite materials ‘silica gel - sodium acetate’ and ‘silica gel – sodium sulphate’ have been studied. The mathematical model and algorithm for determining the basic operating parameters of adsorptive regenerator in the housing and communal services sector have been further developed. The proposed algorithm which involves calculating the air volume passed through the adsorbent layer, the final absolute humidity of air near the outlet from the regenerator, the adsorption and the heat of adsorption during inflow and outflow, the final temperature of the external cold air, the air temperature after mixing the cold external air and the internal warm air in the room near the warm end of the regenerator during inflow, the air temperature after mixing of the cold external air and the warm exhaust air from the premise near the cold end of regenerator during outflow, determining the temperature and moisture efficiency factors has been completed by computing the Reynolds criterion of the adsorbent layer, the coefficient of the hydraulic resistance, the pressure loss, the consumed power of ventilator, summarized adsorption and time to achieve maximal adsorption . The adequacy of suggested mathematical model is confirmed by sufficient correlation of experimental data and calculation results with the proposed algorithm. The performance of adsorptive regenerators based on the adsorbents ‘silica gel – CH3COONa’ and ‘silica gel – Na2SO4’ has been simulated in the conditions of the conventional ventilation system of living quarters. The efficiency of adsorptive regenerators has been compared when ‘silica gel – CH3COONa’ and ‘silica gel – Na2SO4’ used. The correlation of design and efficiency of adsorptive regenerators is shown.

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Performance analysis and optimal charging time investigation of solar air heater with packed bed sensible heat storage device

Solar Energy ◽

10.1016/j.solener.2021.06.007 ◽

2021 ◽

Vol 224 ◽

pp. 718-729

Author(s):

Göker Türkakar

Keyword(s):

Performance Analysis ◽

Heat Storage ◽

Packed Bed ◽

Storage Device ◽

Solar Air Heater ◽

Sensible Heat ◽

Air Heater ◽

Charging Time

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THERMAL MASSES OF ADSORPTIVE HEAT STORAGE DEVICES BASED ON COMPOSITES “SILICA GEL – SODIUM SULPHATE” AND “SILICA GEL – SODIUM ACETATE”

Scientific notes of Taurida National V.I. Vernadsky University. Series: Technical Sciences ◽

10.32838/2663-5941/2021.2-2/07 ◽

2021 ◽

Vol 2 (2) ◽

pp. 44-48

Author(s):

E.A. Belyanovskaya ◽

К.М. Sukhyy ◽

R.D. Lytovchenko ◽

I.V. Sukha ◽

Ya.O. Serhiienko

Keyword(s):

Silica Gel ◽

Sodium Acetate ◽

Heat Storage ◽

Sodium Sulphate ◽

Storage Devices

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Thermal Conductivity Enhancement in a Latent Heat Storage Device

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.860-863.590 ◽

2013 ◽

Vol 860-863 ◽

pp. 590-593

Author(s):

Cha Xiu Guo ◽

Ding Bao Wang ◽

Gao Lin Hu

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Solid State ◽

Liquid Phase ◽

Phase Change ◽

Latent Heat ◽

Heat Storage ◽

Storage Device ◽

Latent Heat Storage ◽

Conductivity Enhancement

High conductivity porosity materials are proposed to enhance the phase change materials (PCM) in order to solve the problem of low conductivity of PCM in the latent heat storage device (LHSD), and two-dimensional numerical simulation is conducted to predict the performance of the PCM by CFD software. During the phase change process, the PCM is heated from the solid state to the liquid phase in the process of melting and from the liquid phase to the solid state in the solidification process. The results show that porosity materials can improve heat transfer rate effectively, but the effect of heat transfer of Al foam is superior to that of graphite foam although the heat storage capacity is almost the same for both. The heat transfer is enhanced and the solidification time of PCM is decreased since the effective thermal conductivity of composite PCM is increased.

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Experimental Study on the Heat Storage/Release Characteristics of a Thermoelectric Heat Pump Phase-Change Thermal Storage Device

2011 International Conference on Computer Distributed Control and Intelligent Environmental Monitoring ◽

10.1109/cdciem.2011.249 ◽

2011 ◽

Author(s):

Min Xu ◽

Ling Zhang ◽

ZB Liu ◽

JL Zhou

Keyword(s):

Experimental Study ◽

Phase Change ◽

Heat Pump ◽

Heat Storage ◽

Thermal Storage ◽

Storage Device ◽

Thermoelectric Heat Pump ◽

Thermoelectric Heat

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Adapting the MgO-CO2 Working Pair for Thermochemical Energy Storage by Doping with Salts: Effect of the (LiK)NO3 Content

Energies ◽

10.3390/en12122262 ◽

2019 ◽

Vol 12 (12) ◽

pp. 2262

Author(s):

Seon Tae Kim ◽

Haruka Miura ◽

Hiroki Takasu ◽

Yukitaka Kato ◽

Alexandr Shkatulov ◽

...

Keyword(s):

Energy Storage ◽

Heat Storage ◽

Low Cost ◽

Salt Content ◽

Eutectic Mixture ◽

High Heat ◽

High Conversion ◽

Wide Availability ◽

Good Potential ◽

Useful Heat

The MgO-CO2 working pair has been regarded as prospective for thermochemical energy storage (TCES) due to its relatively high heat storage capacity, low cost, and wide availability. This study is aimed at the optimization of the molar salt content, α, for the MgO modified with the eutectic mixture of LiNO3 and KNO3 (Li0.42K0.58NO3) which was earlier shown to provide high conversion, Δx, in heat-storage/release processes at 300–400 °C. The composites that have different salt content were prepared and carbonation kinetics was investigated under various conditions (carbonation temperature, Tcarb., is 290–360 °C and CO2 pressure, P(CO2), is 50–101 kPa). Significant accelerating effect was revealed at α ≥ 0.05, and the Δx value was maximized at α = 0.10–0.20. The largest conversion of 0.70 was detected at α = 0.10 and Tcarb. = 350 °C that corresponds to the specific useful heat (Qcomp.) is 1.63 MJ/kg-composite. However, the salt content of 0.20 ensures the high conversion, Δx = 0.63–0.67 and Qcomp. = 1.18–1.25 MJ/kg-composite in the whole temperature range between 290 and 350 °C. The (LiK)NO3/MgO composite with an optimal salt content of 0.20 exhibits reasonable durability through cyclic experiment at 330 °C, namely, the stabilized reacted conversion Δx = 0.34 (Qcomp. = 0.64 MJ/kg-composite). The studied (Li0.42K0.58)NO3 promoted MgO-CO2 working pair has good potential as thermochemical storage material of middle temperature heat (300–400 °C).

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