Deep-borehole heat exchangers (DBHE) are generally coaxial pipes installed in deep boreholes and has become an alternative approach to utilize geothermal energy. Since the performance of the DBHE system can be affected by several parameters, it is important to optimize the design of parameters for the DBHE. In this paper, based on …
Abstract Thermal resistance of ice slows down the charging/discharging process of ice storage systems which results in long operating cycles and thus high energy consumption. To overcome this drawback, various heat transfer enhancement methods have been investigated in the literature. In this paper, a systematic review of the studies …
A new model is proposed for the calculation of energy storage in the heat-supply net. • The proposed method introduced an influence θ to the improved HTES model. • The new method connected the energy stored in …
Sensible heat storage (SHS) involves heating a solid or liquid to store thermal energy, considering specific heat and temperature variations during phase change processes. Water is commonly used in SHS due to its abundance and high specific heat, …
This study shows that the proposed latent heat thermal energy storage unit (M06) significantly reduces PCM melting time compared with vertical (76%), horizontal (66%), and helical-coiled. (53% ...
A-CAES was first proposed in 1972 [17] g. 2 illustrates the working principle of A-CAES: the compression heat of the compressor is used to heat the high-pressure air at the inlet of the expander instead of combustion chamber, and the input and output useful energy are only involved in electrical energy. ...
Overall heat transfer out of or into the bed occurs only via the heat transfer fluid (in the cooling tubes) and by homogeneous heat exchange with the gaseous hydrogen in the bed. 8. The thermal conductivity, specific heat and viscosity of hydrogen do not vary with pressure over the operational regime of the storage system.
Heat exchangers exchange heat in the thermal storage which is stored and retrieved later or can be used as a pre-heating or post-heating devices to save energy. Criteria of design of heat exchangers for …
Thermal energy storage heat exchanger utilizing PCMs is designed and built. • Optimal plate-plate spacing is found to achieve maximum system performance. • Effectiveness greater than 80% at 4795 W power output was achieved. • The number of modular units is
In the process of industrial waste heat recovery, phase change heat storage technology has become one of the industry''s most popular heat recovery technologies due to its high heat storage density and almost constant temperature absorption/release process. In practical applications, heat recovery and utilization speed …
The increase of carbon dioxide emissions is the most important contributor to climate change. A better use of produced energy, increasing systems efficiency and using renewable sources, can limit …
For instance, in [27], direct and indirect heat exchange methods were compared for maximizing the thermal response and storage capacity of solar DHW systems, and the direct heat exchange method ...
The physical model of shell-tube latent heat storage device is shown in Fig. 1.The model consists of two parts: inner tube and shell. In this heat transfer process, the heat is transferred from the HTF to the PCM in the annular space. R i and R o is the radius of the inner tube and shell, respectively, and l is the heat storage unit length.
The PCM thickness was determined by the shell-to-tube diameter ratio. In work by Kalapala and Devanuri [24], values from 3.5 to 4 were reported to be the best ratio to obtain maximum energy storage density and short melting time. The shell-to-tube ratio for M01, M02, M03, M05, and M08 was constant and equal to 3.47.
Latent heat storage (LHS) is one of the key methods to level renewable energy and utilize waste heat. In this method, heat is stored as latent heat of the phase change material (PCM) during melting. Releasing the stored heat in PCM consumes considerable time because the heat release rate is slow when a solidification layer of …
Accurate and precise estimation of waste heat recovery can be estimated by coupling a latent heat thermal energy storage system (LHTES) to waste heat releasing system. The amount of waste heat recovered can be achieved 45% to 85% depending on the thermal energy storage material properties, size of processing industry, …
Thermal energy storage (TES) system is the most eminent storage method that aids in the power generation. Latent heat storage (LHS) is on the rapid mark …
In this technique, energy transfer mechanism is designed in two sections such as, sensible, and latent heat zones, and a heat transfer fluid is circulated into these …
The rapid promotion of renewable and sustainable energy has advanced the development of hydrogen energy and fuel cell technologies [1,2].As shown in Figure 1, the installed capacity of fuel cells, including PEMFCs, direct methanol fuel cells (DMFCs), phosphoric acid fuel cells (PAFCs), solid oxide fuel cells (SOFCs), molten carbonate fuel …
The energy generated during the adsorption stage can be utilized in different fields. Adsorption heat, reaction energy, entropy change, enthalpy change, and exergy efficiency et al. are the values that need to be concerned. In the theoretical aspect, Meunier [51] studied the heat and entropy flows of a specific heat pump. ...
Thermal energy storage ( TES) is the storage of thermal energy for later reuse. Employing widely different technologies, it allows surplus thermal energy to be stored for hours, days, or months. Scale both of storage and use vary from small to large – from individual processes to district, town, or region.
This study indicates storage efficiencies of energy tunnels of up to about 70%. Therefore, energy tunnels have marked potential to store massive amounts of thermal energy in the shallow subsurface ...
In this study, a thermal storage type heat exchanger that combines heat storage and heat exchange functions has proposed and the heat transfer characteristics of the new type of heat exchanger were analyzed through experiments. The proposed thermal storage type heat exchanger has a shell and tube structure and allows mutual heat …
Thermochemical energy storage has substantial potential for greater density storage at temperatures over 200 °C. Heat transfer enhancement of materials and reactors is required. Heat transportation at less than 200 °C by latent heat storage has practical possibilities for waste heat utilization.
The deep borehole heat exchanger (DBHE) shows great potential in seasonal thermal energy storage and its high performance efficiency with smaller land occupancy attracts increasing attention as a promising geothermal energy exploitation technique. With respect to a vertical BHE with extremely long length pipes buried …
Abstract. Significant tensile stresses inside solid thermal energy storage media are induced due to incompatible thermal expansion characteristics. These stresses can cause damage to the often brittle storage material which is associated with a performance loss of thermal properties or the partial loss of long-term mechanical stability.
The first hard rock shallow-lined underground CAES cavern in China has been excavated to conduct a thermodynamic process and heat exchange system for practice. The thermodynamic equations for the solid and air region are compiled into the fluent two-dimensional axisymmetric model through user-defined functions. The …
This chapter reviews the fundamental knowledge developed by the application of the constructal principle to the energy flows in the design of heat exchangers of thermal energy storage systems. It …
3.3 Sensible Heat Thermal Energy Storage. Sensible heat storage is achieved by increasing ( heating) or decreasing ( cooling) the temperature of the storage medium. A typical cycle of sensible heat thermal energy storage (SHTES) system involves sensible heating and cooling processes as given in Fig. 3.3.
However, thermal storage and release properties of the LHTES are limited for the low thermal conductivity of the PCMs, therefore, the performance enhancement of solar driven LHTES system has become a research hotspot in recent years. Panchabikesan et al. [14] found from the parametric study of PCMs and HTF that the inlet temperature of …
Among the three main heat storage methods: sensible heat storage, latent heat (phase change) ... (2017): 256-265. [13] Zhang Long, Dong Jiankai, Jiang Yiqiang and Yao Yang. “A novel defrosting method using …