TY - JOUR

T1 - Thermodynamic Analysis of the New Adsorption Cycle “HeCol” for Ambient Heat Upgrading

T2 - Ideal Heat Transfer

AU - Okunev, B. N.

AU - Voskresensky, N. M.

AU - Girnik, I. S.

AU - Aristov, Yu I.

PY - 2018/7/1

Y1 - 2018/7/1

N2 - Thermodynamic analysis of a new adsorption cycle recently suggested for upgrading ambient heat (the so-called “Heat from Cold” or HeCol cycle) was performed. The energy and entropy balances at each cycle stage and in each converter component were calculated for the methanol–AC-35.4 activated carbon working pair under conditions of ideal heat transfer. It is shown that useful heat can be obtained only if the ambient temperature is below a threshold temperature. The threshold temperature was calculated based on the Polanyi principle of temperature invariance and was experimentally validated. The specific useful heat can reach 200–300 J/(g adsorbent), which is of practical interest. The use of adsorbents with an abrupt change in the adsorption uptake between boundary isosters of the cycle may lead to further enhancement of the useful heat. For the HeCol cycle, the exergy losses under the conditions of ideal heat transfer are small. At low ambient temperature, the losses in the evaporator, condenser, and adsorber are comparable, whereas at higher ambient temperature the main exergy losses originate from the adsorber heating and cooling.

AB - Thermodynamic analysis of a new adsorption cycle recently suggested for upgrading ambient heat (the so-called “Heat from Cold” or HeCol cycle) was performed. The energy and entropy balances at each cycle stage and in each converter component were calculated for the methanol–AC-35.4 activated carbon working pair under conditions of ideal heat transfer. It is shown that useful heat can be obtained only if the ambient temperature is below a threshold temperature. The threshold temperature was calculated based on the Polanyi principle of temperature invariance and was experimentally validated. The specific useful heat can reach 200–300 J/(g adsorbent), which is of practical interest. The use of adsorbents with an abrupt change in the adsorption uptake between boundary isosters of the cycle may lead to further enhancement of the useful heat. For the HeCol cycle, the exergy losses under the conditions of ideal heat transfer are small. At low ambient temperature, the losses in the evaporator, condenser, and adsorber are comparable, whereas at higher ambient temperature the main exergy losses originate from the adsorber heating and cooling.

UR - http://www.scopus.com/inward/record.url?scp=85051116232&partnerID=8YFLogxK

U2 - 10.1134/S1810232818030086

DO - 10.1134/S1810232818030086

M3 - Article

AN - SCOPUS:85051116232

VL - 27

SP - 327

EP - 338

JO - Journal of Engineering Thermophysics

JF - Journal of Engineering Thermophysics

SN - 1810-2328

IS - 3

ER -