scholarly journals Regulation of Cooling Mode of Thermoelectric Bloc

Author(s):  
Evgeniy N. Vasil'ev

With the help of a computational model, the cooling modes of a block of a thermoelectric refrigeration unit designed for ship's provision and freezing chambers are studied. The computational model, based on the numerical solution of a system of nonlinear algebraic equations, takes into account the operating characteristics of a serial thermoelectric module and the thermal resistances of heat removal and supply devices. The dependences of the cooling power and the coefficient of performance of the block on the supply current of the thermoelectric modules are calculated. The analysis of the cooling modes of the thermoelectric block is carried out and recommendations for regulating the current strength depending on the current temperature conditions in the provision and freezing chambers are developed

2021 ◽  
Vol 91 (5) ◽  
pp. 743
Author(s):  
Е.Н. Васильев

A thermoelectric cooling and temperature control system consisting of a thermoelectric module and devices for supplying and removing heat is considered. Based on a mathematical model that uses the operating characteristics of a serial thermoelectric module as initial data, the cooling coefficient of the cooling system was calculated taking into account the thermal resistances of the devices for supplying and removing heat. The dependences of the cooling coefficient on the current strength for different values of the cooling parameters are obtained. The analysis of optimal values of the power supply current of the thermoelectric module is carried out.


2021 ◽  
pp. 301-301
Author(s):  
Lalith Nadimuthu ◽  
Divya Selvaraj ◽  
Kirubakaran Victor

The present study investigates the performance of solar photovoltaic integrated thermoelectric cooler (TEC) using MATLAB Simulink. The enhancement of efficiency has been achieved using an effective heat removal mechanism from the hot side heat sink. Since the hot side temperature is a crucial parameter. The intrinsic material properties like Seebeck coefficient (?), Thermal Conductance (K) and Electrical resistance (R) of the thermoelectric module are carefully estimated using analytical method and reported. The MATLAB Simulink Peltier module is developed based on the estimated intrinsic properties. The effect of system Voltage (V) and Current (A) on the thermal parameters like cooling capacity (QC) and Coefficient of performance (COP) has been investigated. The simulation study is validated by conducting a series of experimental analysis. The experimental model is equipped with a 100 Wp polycrystalline solar photovoltaic module to integrate and power the 12V/5 A of the 60-Watt thermoelectric cooler. Moreover, the results reveal that there is a significant effect of ambient and hot side temperature on the thermoelectric cooler performance. The fin-type conductive mode of heat transfer mechanism is adopted along with the convective forced air-cooling system to achieve effective heat removal from the hot side. The infrared thermographic investigation is carried out for ascertaining effective heat removal.


Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 699
Author(s):  
Cüneyt Ezgi

Strict International Maritime Organization (IMO) rules enable ships to maximize fuel consumption and compliance with the climate. Cooling and heat-pumping technology powered by waste heat makes a substantial contribution to lowering ship gas emissions. This study explores, technically studies, and thermodynamically analyzes the efficiency of ongoing adsorption refrigeration and heating systems using a zeolite–water pair onboard a naval surface ship. An updated Dubin-in-Astakhov equation calculates the equilibrium adsorption potential of the operating pair used in the system. The coefficient of performance (COP) and specific cooling power (SCP)/specific heating power (SHP) values were between 0.109 and 0.384 and between 69.13 and 193.58 W kg−1 for cooling mode, and between 66.16 and 185.26 W kg−1 based on exhaust gas temperature and regeneration, respectively. Up to 27.64% and 52.91% met the cooling and heating load of the case vessel at a full load by the zeolite–water-adsorbed refrigeration/heat-pumping system. The COP of the heat pump and cooling systems was compared to that of adsorption cooling/heat pumps in the literature.


2021 ◽  
Vol 11 (7) ◽  
pp. 3236
Author(s):  
Ji Hyeok Kim ◽  
Joon Ahn

In a field test of a hybrid desiccant cooling system (HDCS) linked to a gas engine cogeneration system (the latter system is hereafter referred to as the combined heat and power (CHP) system), in the cooling operation mode, the exhaust heat remained and the latent heat removal was insufficient. In this study, the performance of an HDCS was simulated at a humidity ratio of 10 g/kg in conditioned spaces and for an increasing dehumidification capacity of the desiccant rotor. Simulation models of the HDCS linked to the CHP system were based on a transient system simulation tool (TRNSYS). Furthermore, TRNBuild (the TRNSYS Building Model) was used to simulate the three-dimensional structure of cooling spaces and solar lighting conditions. According to the simulation results, when the desiccant capacity increased, the thermal comfort conditions in all three conditioned spaces were sufficiently good. The higher the ambient temperature, the higher the evaporative cooling performance was. The variation in the regeneration heat with the outdoor conditions was the most dominant factor that determined the coefficient of performance (COP). Therefore, the COP was higher under high temperature and dry conditions, resulting in less regeneration heat being required. According to the prediction results, when the dehumidification capacity is sufficiently increased for using more exhaust heat, the overall efficiency of the CHP can be increased while ensuring suitable thermal comfort conditions in the cooling space.


2010 ◽  
Vol 31 (2) ◽  
pp. 77-94 ◽  
Author(s):  
Agnieszka Kuczyńska ◽  
Władysław Szaflik

Absorption and adsorption chillers applied to air conditioning systemsThis work presents an application possibility of sorption refrigerators driven by low temperature fluid for air conditioning of buildings. Thermodynamic models were formulated and absorption LiBr-water chiller with 10 kW cooling power as well as adsorption chiller with silica gel bed were investigated. Both of them are using water for desorption process with temperatureTdes= 80 °C. Coefficient of performance (COP) for both cooling cycles was analyzed in the same conditions of the driving heat source, cooling waterTc= 25 °C and temperature in evaporatorTevap= 5 °C. In this study, the computer software EES was used to investigate the performance of absorption heat pump system and its behaviour in configuration with geothermal heat source.


2018 ◽  
Vol 40 (2) ◽  
pp. 220-236 ◽  
Author(s):  
Irfan Ahmad Gondal

This study presents an innovative concept of a compact integrated solar-thermoelectric module that can form part of the building envelope. The heating/cooling modes use the photovoltaic electrical current to power the heat pump. The experimental analysis was carried out and the results of coefficient of performance were in the range 0.5–1 and 2.6–5 for cooling and heating functions, respectively. The study demonstrates that thermoelectric cooler can effectively be used for heating, ventilation, and air conditioning applications by integrating with solar panels especially in cooling applications. The system is environmentally friendly and can contribute in the implementation of zero energy buildings concept. Practical application: In order to help address the challenge of climate change and associated environmental effects, there is continuous demand for new technologies and applications that can be readily integrated into day-to-day life as a means of reducing anthropogenic impact. Heating, ventilation, and air conditioning, as one of the largest energy consumers in buildings, is the focus of many researchers seeking to reduce building energy use and environmental impact. This article proposes using facades and windows that have an integrated modules of solar photovoltaic cells and thermoelectric devices that are able to work together to achieve heating and cooling effects as required by the building without requiring any external operational power.


Author(s):  
Long Quan ◽  
Lei Ge ◽  
Jing Yang ◽  
Bin Zhao ◽  
Zhen Lu ◽  
...  

Pump controlled hydraulic circuit is an energy efficient alternative to valve controlled system, as they eliminate the throttling loss and require less cooling power. In all pump controlled systems, the internal and external leakages of the pump and actuator, especially the unequal flow rates of the single rod cylinder must be compensated. In presently existing solutions, an additional pump or some valves are used to compensate the unequal flow rates, leakages and to pressurize the system. However, these approaches increase the system complexity and complex control strategies are required to improve the overall system dynamic performances. Also, some of them suffer from undesired and uncontrolled pressure and velocity oscillations when the load force is small or its direction changes. This paper addresses the unequal flow rates compensation problem and stability problem of pump controlled single rod cylinder system, and proposes a novel solution for it. The system under consideration utilizes a new designed asymmetric pump which can match the unequal flow rates of the single rod cylinder basically. The feasibility of the new circuit is validated by both mathematics and multi-body simulation model. The results show that the undesired velocity oscillations can be removed up. Furthermore, the operating characteristics and energy efficiency of the arm cylinder with the new scheme based on the designed open-loop and closed-loop strategies are studied on a real excavator. The results show that there is no obvious velocity fluctuation with the asymmetric pump and the position controlled precision is satisfied. Compared with the independent metering circuit, the energy-saving ratio reaches to 57% during a working cycle.


Author(s):  
Chandrakant D. Patel ◽  
Ratnesh K. Sharma ◽  
Cullen E. Bash ◽  
Monem H. Beitelmal

The information technology industry is in the midst of a transformation to lower the cost of operation through consolidation and better utilization of critical data center resources. Successful consolidation necessitates increasing utilization of capital intensive "always-on" data center infrastructure, and reducing the recurring cost of power. A need exists, therefore for an end to end physical model that can be used to design and manage dense data centers and determine the cost of operating a data center. The chip core to the cooling tower model must capture the power levels and thermo-fluids behavior of chips, systems, aggregation of systems in racks, rows of racks, room flow distribution, air conditioning equipment, hydronics, vapor compression systems, pumps and heat exchangers. Earlier work has outlined the foundation for creation of a "smart" data center through use of flexible cooling resources and a distributed sensing and control system that can provision the cooling resources based on the need. This paper shows a common thermodynamic platform which serves as an evaluation and basis for policy based control engine for such a "smart" data center with much broader reach - from chip core to the cooling tower. Computational Fluid Dynamics modeling is performed to determine the computer room air conditioning utilization for a given distribution of heat load and cooling resources in a production data center. Coefficient of performance (COP) of the computer room air conditioning units, based on the level of utilization, is used with COP of other cooling resources in the stack to determine the COP of the ensemble. The ensemble COP represents an overall measure of the performance of the heat removal stack in a data center.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 550 ◽  
Author(s):  
Hansol Lim ◽  
Jae-Weon Jeong

The purpose of this study is to investigate the suitable operation and performance of a thermoelectric radiant panel (TERP) in the heating operation. First, the hypothesis was suggested that the heating operation of TERP can operate without a heat source at the cold side according to theoretical considerations. To prove this hypothesis, the thermal behavior of the TERP was investigated during the heating operation using a numerical simulation based on the finite difference method. The results indicated that it is possible to heat the radiant panel using a thermoelectric module without fan operation via the Joule effect. A mockup model of the TERP was constructed, and the numerical model and hypothesis were validated in experiment 1. Moreover, experiment 2 was performed to evaluate the necessity of fan operation in the heating operation of TERP regarding energy consumption. The results revealed that the TERP without fan operation showed the higher coefficient of performance (COP) in the heating season. After determining the suitable heating operation of the TERP, prediction models for the heating capacity and power consumption of the TERP were developed using the response surface methodology. Both models exhibited good R2 values of >0.94 and were validated within 10% error bounds in experimental cases. These prediction models are expected to be utilized in whole-building simulation programs for estimating the energy consumption of TERPs in the heating mode.


2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Shahram Derakhshan ◽  
Alireza Yazdani

In critical situations such as floods and earthquakes, the relief forces require a refrigeration for pharmaceuticals and vaccines, which could operate without an electrical energy and the alternative energies, such as solar energy, engine exhaust gases heat, and wind energy. In this paper, a refrigeration cycle has been modeled as an adsorption refrigeration cycle with an activated carbon/methanol as adsorbent/adsorbate pair and two sources of energy—solar energy and engine exhaust gases heat. The solar cycle had a collector with area of 1 m2 and the exhaust gas cycle included a heat exchanger with 100 °C temperature difference between inlet and outlet gases. The temperature profile in adsorbent bed, evaporator, and condenser was obtained from modeling. Moreover, the pressure profile, overall heat transfer coefficient of collector and adsorbent bed, concentration, and the solar radiation were reported. Results represented the coefficient of performance (COP) of 0.55, 0.2, and 0.56 for complete system, solar adsorption refrigeration, and exhaust heat adsorption refrigeration, respectively. In addition, exhaust heat adsorption refrigeration has a value of 2.48 of specific cooling power (SCP). These results bring out a good performance of the proposed model in the climate of Iran.


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