ABSTRACT: This paper describes current developments in seasonal thermalenergy storage, which has seen improved interest in recent years due to the growing awareness of global warming and other environmental problems. The main seasonal thermalenergy storage system is underground thermalenergy storage system aquifer thermalenergy storage system, bore hole thermalenergy storage system, cavern rock thermalenergy storage system, hot water thermalenergy storage system, gravel water thermalenergy storage system combination with a heat pump and solar thermal collectors. These systems can able to overcome the day-night issues as well as the seasonal difficulties associated with the solar power usage for air conditioning system. In this paper added a detailed description on all the above underground thermalenergy storage system and information about solar collector and heat pump used for the transfer of heat energy. This study discussed about the various techniques that can be used to temperature control which have very high demand in the future days.
Figure 3.2 shows the overall project flowchart starting from semester 1 until semester 2. Based on the project title, ThermalEnergy Harvesting for Electronic Device Application, the first thing to do is study and understand about the thermalenergy harvesting which is based on the concept of thermoelectric. Next, based on the objective, a most suitable heat producing device that can supply thermal waste energy continuously or in a long period need to be identified. Various thermal waste energy is identified and investigated by measuring the temperature or heat released by the devices such as clothes iron, kettle and air conditioner using a device called Resistance Temperature Detector (RTD).
The present work intends to predict the thermal effect of a borehole thermalenergy store (BTES) on the subsurface in the case of flowing groundwater by simulation with the software FEFLOW. Predicting thermal effects on the subsurface or grouting using finite element modeling has been done by other authors before (Wo ł oszyn and Go ł a ś 2013; Rees and He 2013; Wagner et al. 2013; Zhang et al. 2011), but the properties of the surrounding geological formation itself are generally simplified or focus on the grouting material only. Predicting thermal effects on the subsurface is essential for construction approvals by authorities and should not exceed a threshold value of 6 K (VDI-Richtlinien 2011). In this study, a detailed examination of the geology has been included into the FEFLOW model. The model has been further enhanced by integrat- ing a newly developed add-on, which significantly reduces computation times and al- lows the coupling of TRANSYS with FEFLOW (Bauer et al. 2011). The resulting model has then been validated against measured data spanning a 2-year period of oper- ation of the BTES in Crailsheim.
Cold ThermalEnergy Storage is a means of storing energy at night during off peak periods when electricity demand is lower for use during on-peak periods. Energy is stored in cold thermalenergy storage (CTES) in the form of cooling capacity. Cooling capacity can be stored by chilling or freezing various fluids and media such as water, glycol and eutectic salts. The choice of media will depend on the purpose of the storage device and how effective the medium of storage is in storing latent energy or sensible energy. Water is the most widely used media of storage for various reasons, which include its availability, its compatibility with a wide variation of cooling systems and its being non toxic.
In the present paper, we developed relationship to predict temperature dependence of thermalenergy for geophysical minerals by using a formulation for volume dependence of isothermal Anderson- Grünesien parameter which is valid up to extreme compression limit P →∞ or V→0. The present relationship are applied on geophysical minerals viz. MgO and Mg2SiO4 to validate the present expressions. Present study also reveals that temperature dependence of thermalenergy shows linearity with elastic constants. A close agreement between results and experimental data discloses the validity of present work.
Combined heat and power (CHP) systems in buildings present a control challenge for their efficient use due to their simultaneous production of thermal and electrical energy. The use of thermalenergy storage coupled with a CHP engine provides an interesting solution to the problem – the electrical demands of the building can be matched by the CHP engine while the resulting thermalenergy can be regulated by the thermalenergy store. Based on the thermalenergy demands of the building the thermal store can provide extra thermalenergy or absorb surplus thermalenergy production. This paper presents a multi-input multi-output (MIMO) inverse dynamics based control strategy that will minimise the electrical grid utilisation of a building, while simultaneously maintaining a defined operative temperature. Electrical demands from lighting and appliances within the building are considered. In order to assess the performance of the control strategy, a European Standard validated simplified dynamic building physics model is presented that provides verified heating demands. Internal heat gains from solar radiation and internal loads are included within the model. Results indicate the effectiveness of the control strategy in minimising the electrical grid use and maximising the utilisation of the available energy over conventional heating systems.
Developing efficient and inexpensive energy storage devices is as important as developing new sources of energy. The thermalenergy storage (TES) can be defined as the temporary storage of thermalenergy at high or low temperatures. The TES is not a new concept, and at has been used for centuries. Energy storage can reduce the time or rate mismatch between energy supply and energy demand, and it plays an important role in energy conservation. The technology of thermalenergy storage has been developed to a point where it can have a significant effect on modern life. The major nontechnical use of thermal storage was to maintain a constant temperature in dwelling, to keep it warm during cold winter nights. Large stones, blocks of cast iron, and ceramics were used to store heat from an evening fire for the entire night. With the advent of the industrial revolution, thermalenergy storage introduced as a by-product of the energy production.
As shown in Figure 5 (a), general machine learning is divided into instruction learning, non-instruction learning, and reinforcement learning. After the feature extraction through non-instruction learning, The structure is repeated. Reinforcement learning is a form of machine learning that generally goes through repeated trial and error and adapts the output to the direction in which the compensation value grows, with the input having the order in the objective function as a variable. As shown in Figure 5 (b), some of the thermalenergy control equipmenta such as the heat exchanger equipped for data measurement (eg. IoT heat exchanger capable of data collection) is environmentally defined, and the agent is defined as the subject who operates the equipment. In addition, the operation state and the control signal are replaced with situations and behaviors, respectively, and an expectation value of the output is generated by approximating the learning network (DQN) function for the purpose of improving thermal efficiency of the thermal user equipment room facility. This expectation value is used as the input of the controller and the change of the environment accompanied by it changes the situation. This situation is gathered as a new input, And the Q function is generated by the proposed algorithm.
Abstract. Avalanches can exhibit many different flow regimes from powder clouds to slush flows. Flow regimes are largely controlled by the properties of the snow released and entrained along the path. Recent investigations showed the temperature of the moving snow to be one of the most important factors controlling the mobility of the flow. The temperature of an avalanche is determined by the tempera- ture of the released and entrained snow but also increases by frictional processes with time. For three artificially released avalanches, we conducted snow profiles along the avalanche track and in the deposition area, which allowed quantifying the temperature of the eroded snow layers. This data set al- lowed to calculate the thermal balance, from release to de- position, and to discuss the magnitudes of different sources of thermalenergy of the avalanches. For the investigated dry avalanches, the thermalenergy increase due to friction was mainly depending on the effective elevation drop of the mass of the avalanche with a warming of approximately 0.3 ◦ C per 100 vertical metres. Contrarily, the temperature change due to entrainment varied for the individual avalanches, from − 0.08 to 0.3 ◦ C, and depended on the temperature of the snow along the path and the erosion depth. Infrared radiation thermography (IRT) was used to assess the surface tempera- ture before, during and just after the avalanche with high spa- tial resolution. This data set allowed to identify the warmest temperatures to be located in the deposits of the dense core. Future research directions, especially for the application of IRT, in the field of thermal investigations in avalanche dy- namics are discussed.
For example for in cooling or heat absorbing applications endothermic reactions should be carried out by using some chemical mixture where heat energy available is utilized for carrying out the endothermic reaction and hence its lowers the surrounding temperature And in similar case Exothermic reaction are also used in heating applications , this ids carried out by reacting some chemical mixture which reacts and liberates heat energy which is further utilized for heating application of the surrounding. There are three main methods of storing thermalenergy in any material: reversible chemical energy, sensible thermalenergy and latent thermalenergy. Chemical energy is absorbed or released when a chemical reaction occurs in a material, thus changing the organization of the molecules. If this process is reversible, it can be used to capture and recover energy. An example of this is splitting water into its component gases, diatomic oxygen and diatomic hydrogen and then recombining them into water. This can also be done to ammonia through the reversible Haber process by combining and separating the nitrogen and hydrogen atoms.
From the brainwriting sessions, we determined the three critical subsystems for this project are thermalenergy storage, heating, and distribution. We created separate Pugh Matrices (Appendix D) for each subsystem. The thermalenergy storage Pugh matrix compares barrels, insulated tanks, underground tanks, no tank, and PCMs against one another. Based on the results, the insulated tank appears to be the best result. Digging a large underground trench would not be feasible because of the time and expense of such an endeavor. Using a phase change material may not be the best approach either because most PCMs have a melting point far higher than the max temperature of our system. The heating element Pugh matrix compares resistive heaters, direct solar radiation, diode heaters, and combustion. Overall, the diode heating element outperformed the other options. This is reassuring because our sponsor greatly prefers using a DC diode immersion heater. Lastly, we compared PVC, copper, stainless steel, and garden hose for the distribution system of our device. PVC is the clear winner here; the two metals are much too expensive and are about as easy to manufacture. Hose may be used for some components, as it allows flexibility in the design, but its lack of durability and need for thermal insulation make it a poor primary building material.
The present work aims to manage the thermalenergy stored from concentrated solar power (CSP) research plant, in order to obtain the best operating condition of CSP system. This plant consists of solar collector field of 120 kW peak thermal capacity, thermal storage tank with 3 tons of therminol-66 oil, an organic rankine cycle (ORC) of 8 kW nominal electric power production capacity, and thermally driven absorption chiller (TDC) of 35 kW cooling capacity. The system was modeled mathematically then calculated using engineering equation solver (EES) software in order to analyze the performance at similar conditions to the real ones to ensure the feasibility of the presented study. When increasing the input thermal power for both ORC and TDC, the kWh cost decreases. The lowest price for ORC kWh is 1.131 $/kWh when 100% of the stored thermal power is used by ORC to generate electricity. Also, the lowest price for TDC kWh is 0.1214 $/kWh when 100% of the stored thermal power is directed to the TDC. To compromise between both ORC and TDC, The best operating condition is obtained when about 45.83% from stored thermal power is used for ORC and 54.17% is used for TDC. In this case, the cost of electrical kWh from ORC is about 1.26 $, while the cost of refrigerant kWh from TDC is about 0.126 $.
Efficient utilisation of solar energy is increasingly being considered as a promising solution to global warming and a means of achieving a sustainable development for human beings. Because solar energy has low-density and intermittency, ThermalEnergy Storage (TES) plays a pivotal role in balancing energy demand and energy supply. TES technologies rely on high-quality Phase Change Materials (PCMs), which should have high heat storage capacity and excellent heat transfer performance. PCMs have received extensive research interest during the last decade, and they were investigated in a variety of applications: energy saving buildings , solar still , solar cooker [3, 4], industrial waste heat recovery  and solar power plants .
Phase change material stores the energy with minimum temperature or maximum temperature for later use. It will reduce the gap between demand and supply of thermalenergy. The storage cycle is varies (daily, weekly and seasonal) depends on requirement and design. Their input and output are thermalenergy so there is no another energy transaction are takes place and energy losses are minimized. Reason for useing PCM as thermalenergy storage medium is non corrosive, green solution, used as spare, reduced running cost, stability, increased capacity and cost effective. Hence the phase change material is selected as energy storage medium.
Abstract— Determination of thermocline thickness requires a continuous profile of temperature distribution. Difficulty in determining thermocline thickness arises for the case of discrete temperature data, since the profile formed could not be used to estimate the thermocline thickness. This paper discusses a practical method for formulation of thermocline thickness of stratified thermalenergy storage. Curve fitting by iterative method was adopted to identify the functions which could represent the S -curve of temperature distribution. Based on the functions, thermocline thickness was formulated using functional relationship of temperature profile. Results identified two functions which could represent S -curve of temperature distribution, namely sigmoid dose response (S DR) and four parameter sigmoid (FPS ) functions. Both functions were observed to well fit the temperature distributions having coefficient determination more than 0.99. Based on evaluations the formulations were capable to be utilized for evaluation of thermocline thickness of the stratified TES . The methods offer an advantage to obtain an exact value of thermocline thickness.
Conventional power generation approach generally involves converting the energy contained in fuels first into thermalenergy in a combustion unit, then converting the thermalenergy to mechanical energy by a prime mover, with the mechanical energy being converted to electrical energy by the generator. External combustion systems have different equipment for all the three steps of conversion.
Summary. — Geothermal technologies use renewable energy resources to generate electricity and direct use of heat while producing very low levels of greenhouse- gas (GHG) emissions. Geothermal energy is the thermalenergy stored in the underground, including any contained ﬂuid, which is available for extraction and conversion into energy products. Electricity generation, which nowadays produces 73.7 TWh (12.7 GW of capacity) worldwide, usually requires geothermal resources temperatures of over 100 ◦ C. For heating, geothermal resources spanning a wider range of temperatures can be used in applications such as space and district heating (and cooling, with proper technology), spa and swimming pool heating, greenhouse and soil heating, aquaculture pond heating, industrial process heating and snow melting. Produced geothermal heat in the world accounts to 164.6 TWh, with a capacity of 70.9 GW. Geothermal technology, which has focused for decades on ex- tracting naturally heated steam or hot water from natural hydrothermal reservoirs, is developing to more advanced techniques to exploit the heat also where under- ground ﬂuids are scarce and to use the Earth as a potential energy battery, by storing heat. The success of the research will enable energy recovery and utilization from a much larger fraction of the accessible thermalenergy in the Earth’s crust.
In the span of past few decades, population, urbanization and industrialization have transformed the mankind liv- ing standard and dynamics of the nature. Certainly, energy is the basic need for all living organisms. Energy is the route towards the economic growth. The evidence shows that the countries faced with energy crises are left behind in the economic activities; as a result, people are deprived. This study reviewed the available renewable energy resources and potential with positive and negative aspects. This study comprehensively discusses the renewable macro and micro energy resources studied in the past two decades reported in various studies. The paper is divided into two sections; the first section discusses the energy produced in the macro level and the second section dis- cusses the energy produced using different strategies and techniques in the micro level. The potential and positive outcomes of the energy resources were identified. New paradigm of micro energies and importance of reusing the available resource of micro energy using different resources like energy harvesting on the road surface, vibration, airflow, radio frequency and thermalenergy etc. were discussed. Lastly, the study focus does not only review but also finds the potential and opportunities for the researchers in the future to utilize the renewable energy resources. Keywords: macro and micro energy resources, renewable energy, renewable energies potential.