Thermoelectric Refrigeration

Currently, energy demand and environmental pollution have boosted the evolution of different environment friendly technologies for the development of clean and renewable energies. That is why scientific research allows us to demonstrate the use of solid state based devices implementing temperature changes by electric induction. Given the above, a combined thermic generation system is taken into consideration, consisting in an environmentally friendly thermoelectric generator and refrigerator, wich is fueled and controlled by an electric fluid. Therefore, this study gives an approch and mathematic demonstrations to the concepts of greater relevance about the thermoelectric device and the effects of greater incidence, responsible for giving advantageous characteristics to the implementation of Peltier cells as a basic device in a cooling system for smaller applications, maintaining an ecological system, clean and without detrimental effects to the ozone layer, since there is no C02 emissions into the atmosphere.

The high reliability, the absence of working °uid and auxiliary pipes in the thermoelectric cooling application have attracted the attention of researchers in the last two decades. However, the use of thermoelectric airconditioning system for building application has not been entirely explored due to its low coe±cient of performance (COP) compared to the conventional air conditioning system. To overcome this primary limitation, di®erent COP enhancement techniques of ther-moelectric for air conditioning system building application are made available. This paper provides the recent development of thermoelectric air conditioning system in building applications, such as thermoelectric radiant panel ceiling, thermoelectric air duct system and thermoelectric cooling facades. It also provides the di®erent strategies to enhance its performance in order to ¯t this technology in real building applications such as the integration of water-cooling system, phase change materials, evaporator cooling system and nano°uid micro-channel heat sinks. Lastly, the challenges of thermoelectric airconditioning systems and future research directions are discussed.

The research conducted and described in this paper focuses on the design of a cooling system using thermoelectric or peltier module (TEM) and heatsinks with considerations for temperate climatic conditions. A case study of Nigeria has been chosen. Nigeria as a tropical region experiences high temperature difference between the year (18-40℃) with sunhours ranging between (100-210 hrs) monthly, such that the desire for chilled beverages almost throughout the day becomes paramount neccesitating the need for a peltier mobile cooler in tropical regions especially with inadequate electricity supply. A 9-litre rectangular shaped cooler was chosen with an area of 1.155m 2 , a dimension of 0.65 × 0.35, estimated to contain 120 beverages with an estimated heat load of 483W. It is estimated to use five thermoelectric modules, a temperature sensor, tec controller, DC powered battery and ten heat sinks. Comparatively, the design criterias of these peltier cooler were compared with the performance evaluation of existng similar designs and found to be within optimum performance levels. At 10℃, the thermoelectric modules are powered to start cooling until the beverages are at 0℃ (estimated to be a period of fifteen minutes), afterwhich the tec controller turns off power and the system is temporarily off until a temperature of 10℃ is detected by the temperature sensor and a re-cooling is initiated. With these the frozen beverage products received in the morning can be re-cooled as many times as possible.

The thermoelectric heat pump comprises one or more thermoelectric modules having a hot side connected to a first heat exchanger and a cold side connected to a second heat exchanger, and is characterized in that it comprises a pair of elongated bar-like elements made of an electrically and thermally insulating material which are arranged at two parallel sides of the heat exchangers, at least partly interposed between facing flanges of said heat exchangers, at least one of said elongated bar-like elements including electric conductors for supplying power to the thermoelectric modules, as well as conductors for supplying control signals therefor, and that said heat exchangers contacting the thermoelectric modules are linked one another via a plurality of fasteners, each fastener being formed of a substantially C-shaped metal clip.

This paper describes the development stages and performance of a solar powered thermoelectric refrigerator. It is carried out by installing a conventional thermoelectric refrigerator in a stand alone photovoltaic system for household usage. This photovoltaic driven refrigerator is powered by a field of solar panels, a battery bank, a solar charge controller, and an inverter. In this project, the output power of the photovoltaic system and the capability of the battery bank are determined. A compact thermoelectric refrigerator of 22 watts is applied to be investigated in respect to cooling effect produced. To make the device portable, daytime use and nighttime use of the refrigerator are treated in different ways. The effect of door-opening upon the cooling temperature produced by the photovoltaic driven thermoelectric refrigerator is investigated too. In order to efficiently operate this solar powered refrigerator, the sizing of this stand-alone photovoltaic system and the optimum tilt angle of the photovoltaic array must firstly be determined to maximize the electricity generation for matching the load requirement.

http://eprints.um.edu.my/6795/

The key objective of this study is to analyse the heat transfer processes involved in the evaporation and condensation of water in a water distillation system employing a thermoelectric module. This analysis can help to increase the water production and to enhance the system performance. For the analysis, a water distillation unit prototype integrated with a thermoelectric module was designed and fabricated. A theoretical model is developed to study the effect of the heat added, transferred and removed, in forced convection and laminar flow, during the evaporation and condensation processes. The thermoelectric module is used to convert electricity into heat under Peltier effect and control precisely the absorbed and released heat at the cold and hot sides of the module, respectively. Temperatures of water, vapour, condenser, cold and hot sides of the thermoelectric module and water production have been measured experimentally under steady state operation. The theoretical and experimental water production were found to be in agreement. The amount of heat that needs to be evaporated from water-vapour interface and transferred through the condenser surface to the thermoelectric module is crucial for the design and optimization of distillation systems.

An efficient thermoelectric distillation system has been designed and constructed for production of drinkable water. The unique design of this system is to use the heat from hot side of the thermoelectric module for water evaporation and the cold side for vapour condensation simultaneously. This novel design significantly reduces energy consumption and improves the system performance. The results of experiments show that the average water production is 28.5 mL/h with a specific energy consumption of 0.00114 kW h/mL in an evaporation chamber filled with 10 Â 10 Â 30 mm 3 of water. This is significantly lower than the energy consumption required by other existing thermoelectric distillation systems. The results also show that a maximum temperature difference between the hot and cold side of the ther-moelectric module is 42.3 °C, which led to temperature increases of 26.4 °C and 8.4 °C in water and vapour, respectively.

I. Abstract— In this paper, a thermal model has been developed for a water distillation system which uses a thermoelectric module. The thermoelectric module cools a heat exchanger and extracts the latent heat of condensation from the water vapour at the cold side, releasing heat at the hot side to supplement the water heating. It is important to take into account the temperature distribution and the heat transfer of the thermoelectric distillation system to enhance the thermal performance. The model shows that the rate of water condensation is dependent upon the cold side temperature of the thermoelectric module, vapour temperature, geometry of the heat exchanger and the convection heat transfer coefficient of the heat exchanger at the cold side. The thermal model is used to analyses the experimental data of the thermoelectric distillation system. The results shows that the local convection heat transfer coefficient is 8 W/m 2 .K. Measurements of the distilled water show that the produced water has similar quality to the tap water in terms of PH, total dissolved solids and electrical conductivity values.

--- --- Description: --- --- --- Technical field: --- [0001] The present invention generally relates to the field of thermoelectricity, and particularly an improved kind of thermoelectric heat pump. --- Prior art: --- [0002] Thermoelectric heat pumps are solid state devices which make use of a thermoelectric effect known as Peltier effect for refrigerating and/or heating purposes in the domestic and/or industrial field. [0003] These devices generally include a thermoelectric module which is formed of an array of thermoelectric elements consisting in conductors or semiconductors of the P and N type which are connected electrically in series and thermally in parallel together. The thermoelectric elements are assembled on supports of electrically insulating and thermally conducting material which is generally a ceramic-like material. The thermoelectric modules are connected to heat exchangers for forming a heat pump intended for domestic and industrial applications. [0004] The thermoelectric heat pumps known in the art generally exhibit some drawbacks concerning the way the heat exchangers are connected to the thermoelectric modules and how the latter are electrically connected to a power source, as well as to a controller. [0005] US Patent Application No, 2003/193087A1 discloses a thermoelectric heat pump having the pre-characterising features of claim 1. However, a drawback of the thermoeletric heat pump disclosed therein is that the heat exchanger cannot be easily assembled to and disassembled from the thermoelectric modules. [0006] From US Patent No. 5.099.550 it is known to use a resilient C-shaped clamp made of a thermoplastic material to hold a heat sink on to a semiconductor device to be cooled. However, such a clamp hardly compensates for the amount of settling between the heat sink and the semiconductor device and thus cannot ensure that the desired tensioning force is provided also on the long term. [0007] The present invention addressees these drawbacks of the known art by providing an improved thermoelectric heat pump.

Currently, energy demand and environmental pollution have boosted the evolution of different environment friendly technologies for the development of clean and renewable energies. That is why scientific research allows us to demonstrate the use of solid state based devices implementing temperature changes by electric induction. Given the above, a combined thermic generation system is taken into consideration, consisting in an environmentally friendly thermoelectric generator and refrigerator, wich is fueled and controlled by an electric fluid. Therefore, this study gives an approch and mathematic demonstrations to the concepts of greater relevance about the thermoelectric device and the effects of greater incidence, responsible for giving advantageous characteristics to the implementation of Peltier cells as a basic device in a cooling system for smaller applications, maintaining an ecological system, clean and without detrimental effects to the ozone layer, since there is no C02 em...

The thermoelectric heat pump has a mounting and heat dissipating device for the electronic components of a control electronic circuit board, and comprises a pair of heat exchangers and one or more thermoelectric modules having opposite sides which are each in thermal contact with said heat exchangers. The thermoelectric modules are electrically connected to power supply conductors and the control electronic circuit board has electrical contacts for connection to terminals of the power supply conductors of the thermoelectric modules. The mounting and heat dissipating device is formed of a plate made of a material having a high thermal conductivity, and comprises a first mounting portion for the electronic components of the control electronic circuit board and a second connecting portion which is intended to be fixed to a surface of a heat exchanger. The plate acts as a thermal bridge between the electronic components of the control electronic circuit board and the heat exchanger, and is capable of mechanically fastening the control electronic circuit board to the thermoelectric heat pump in an operative position in which the contacts of the control electronic circuit board can be electrically connected to the terminals of the power supply conductors of the thermoelectric modules.

Currently, energy demand and environmental pollution have boosted the evolution of different environment friendly technologies for the development of clean and renewable energies. That is why scientific research allows us to demonstrate the use of solid state based devices implementing temperature changes by electric induction. Given the above, a combined thermic generation system is taken into consideration, consisting in an environmentally friendly thermoelectric generator and refrigerator, wich is fueled and controlled by an electric fluid. Therefore, this study gives an approch and mathematic demonstrations to the concepts of greater relevance about the thermoelectric device and the effects of greater incidence, responsible for giving advantageous characteristics to the implementation of Peltier cells as a basic device in a cooling system for smaller applications, maintaining an ecological system, clean and without detrimental effects to the ozone layer, since there is no C02 em...

--- --- Description: --- ---
--- Technical field: ---
[0001] The present invention generally relates to the
field of thermoelectricity, and particularly an improved
kind of thermoelectric heat pump.
--- Prior art: ---
[0002] Thermoelectric heat pumps are solid state devices
which make use of a thermoelectric effect known
as Peltier effect for refrigerating and/or heating purposes
in the domestic and/or industrial field.
[0003] These devices generally include a thermoelectric
module which is formed of an array of thermoelectric
elements consisting in conductors or semiconductors of
the P and N type which are connected electrically in series
and thermally in parallel together. The thermoelectric
elements are assembled on supports of electrically insulating
and thermally conducting material which is generally
a ceramic-like material. The thermoelectric modules
are connected to heat exchangers for forming a heat
pump intended for domestic and industrial applications.
[0004] The thermoelectric heat pumps known in the
art generally exhibit some drawbacks concerning the way
the heat exchangers are connected to the thermoelectric
modules and how the latter are electrically connected to
a power source, as well as to a controller.
[0005] US Patent Application No, 2003/193087A1 discloses
a thermoelectric heat pump having the pre-characterising
features of claim 1. However, a drawback of
the thermoeletric heat pump disclosed therein is that the
heat exchanger cannot be easily assembled to and disassembled
from the thermoelectric modules.
[0006] From US Patent No. 5.099.550 it is known to
use a resilient C-shaped clamp made of a thermoplastic
material to hold a heat sink on to a semiconductor device
to be cooled. However, such a clamp hardly compensates
for the amount of settling between the heat sink
and the semiconductor device and thus cannot ensure
that the desired tensioning force is provided also on the
long term.
[0007] The present invention addressees these drawbacks
of the known art by providing an improved thermoelectric
heat pump.