Novel experiments on COP improvement of thermoelectric air coolers

Dizaji, Hamed Sadighi; Jafarmadar, Samad; Khalilarya, Shahram

doi:10.1016/j.enconman.2019.03.025

Cited by 49 publications

(12 citation statements)

References 28 publications

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“…T w,o and T w,i are the water temperatures at the outlet and inlet of the condenser ( • C). Using Equation (2) [32], the COP was calculated for open-loop and closed-loop systems. In an open-loop system, heated water from the condenser is dumped directly to the outside, while water at the heat storage tank circulates and is reheated at the condenser and returns to the heat storage tank for a closed-loop system:…”

Section: Cop Of the Awhpmentioning

confidence: 99%

Heating Performance Analysis of an Air-to-Water Heat Pump Using Underground Air for Greenhouse Farming

2020

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As one of the main businesses in Jeju-do in South Korea, specialized local products are grown in greenhouses. For greenhouse farming, it is preferable to use geothermal heat pump systems for energy conservation because of the stable temperature of the ground. In the same manner, heat pumps using underground air is recommended for greenhouse farming since underground air can easily be obtained from porous volcanic rocks in Jeju-do. However, direct usage of the underground air is not feasible for planting in the greenhouse or livestock care because the underground air is relatively humid and its temperature is low. For the present study, the heating performance of an air-to-water heat pump which used underground air as a heat source for greenhouse farming during the winter was assessed through measurements. In addition, the economic impact of the air-to-water heat pump (AWHP) was compared with a conventional air heater. According to the results, an AWHP can save more than 70% of the total heating costs compared with a conventional air heater. In sum, the utilization of the air-to-water heat pump using underground air can have a positive impact on reducing energy consumption as well as provide direct economic benefits.

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Section: Cop Of the Awhpmentioning

confidence: 99%

Heating Performance Analysis of an Air-to-Water Heat Pump Using Underground Air for Greenhouse Farming

2020

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“…Building technology has emerged as one region of particular interest for thermoelectric applications. Numerous works have examined the possibility to use thermoelectrics for the purpose of air conditioning in theoretical [13][14][15][16] and experimental [17][18][19][20][21][22][23] setups. The predominant use case is the cooling case, while one study focuses on an IoT-control approach and also uses the heating function in reversed operation mode [23].…”

Section: Introductionmentioning

confidence: 99%

“…Irshad implements 24 TEEs with heat sinks in an supply air duct and reaches cooling COPs of 0.679 at a cooling load of 500 W. The excess heat is transferred to outdoor air [22,23]. The effect of joining several TEEs in series in an air flow is investigated by [17]. They find that the efficiency of 6 joined TEE is twice the effiency of only 2 TEE when operating at the same total electrical power input.…”

Section: Introductionmentioning

confidence: 99%

Thermoelectric building temperature control: a potential assessment

Hagenkamp

Blanke

Döring

2021

Int J Energy Environ Eng

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This study focuses on thermoelectric elements (TEE) as an alternative for room temperature control. TEE are semi-conductor devices that can provide heating and cooling via a heat pump effect without direct noise emissions and no refrigerant use. An efficiency evaluation of the optimal operating mode is carried out for different numbers of TEE, ambient temperatures, and heating loads. The influence of an additional heat recovery unit on system efficiency and an unevenly distributed heating demand are examined. The results show that TEE can provide heat at a coefficient of performance (COP) greater than one especially for small heating demands and high ambient temperatures. The efficiency increases with the number of elements in the system and is subject to economies of scale. The best COP exceeds six at optimal operating conditions. An additional heat recovery unit proves beneficial for low ambient temperatures and systems with few TEE. It makes COPs above one possible at ambient temperatures below 0 $$^\circ $$ ∘ C. The effect increases efficiency by maximal 0.81 (from 1.90 to 2.71) at ambient temperature 5 K below room temperature and heating demand $$\dot{Q}_h={100} W$$ Q ˙ h = 100 W but is subject to diseconomies of scale. Thermoelectric technology is a valuable option for electricity-based heat supply and can provide cooling and ventilation functions. A careful system design as well as an additional heat recovery unit significantly benefits the performance. This makes TEE superior to direct current heating systems and competitive to heat pumps for small scale applications with focus on avoiding noise and harmful refrigerants.

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“…Besides, the thermal design and optimization will generate positive significance for the thermoelectric refrigeration system performance improvement. [24][25][26][27] For example, Chen et al 28 explored the influence of external heat exchangers that favors improving the thermoelectric cooling performance. Riffat and Ma 29 introduced the heat exchanger thermal resistance for calculating the hot-end temperature by considering the natural convection, forced air convection, and water-cooled exchanger.…”

Section: Introductionmentioning

confidence: 99%