Page 97 - Low Temperature Energy Systems with Applications of Renewable Energy

86 Low-Temperature Energy Systems with Applications of Renewable Energy

System data are:
- Thermal load is 1 kW.
- Temperature of the glycol at the heat pump inlet: t p1 ¼ 3 C.

- Glycol temperature at the outlet of the heat pump: t p2 ¼ 1 S.

- Water temperature at the heat pump inlet: t w1 ¼ 27 S.

- Water temperature at the outlet of the heat pump: t w2 ¼ 32 C.

- Temperature difference at the evaporator and condenser outlet: Dt min ¼ 5 C.

- Ambient temperature is 5 S.
4. Determine the thermodynamic efficiency of an air-air heat pump with a thermal capacity of

3 kW. Ambient air temperature is: 1 C (Case A); þ2 C (Case B). Air temperature in the

room is 18 S; outside air temperature is 20 S; air temperature difference in the evapo-

rator and condenser is Dt ¼ 10 S. Assume that Dt max ¼ 10 S and heat pump working fluid

is R152a.
References
[1] Pisarev VE. Heat pumps and refrigerators. Manual e K. KNUCA. 2002.
[2] 2.04.05-91 “construction standards and heating, ventilation and condition rules”.
[3] 2.01-99 “energy saving in buildings, norms of heat protection and heat, water and energy
supply”.
[4] Bezrodny MK. Power efficiency of heat pump schemes of heat supply. M.K. Bezrodny,
H.O. Prytula. K. NTU «KPI»; 2012.
[5] Gershkovich VF. The peculiarities of designing building heat supply systems with heat
pumps. K. Ukrainian Architecture Academy PE “Energominimum”; 2009.
[6] Bezrodny MK. Energy efficiency of the heat pump system of ventilation with heat recu-
perator and recirculation of exhaust air. M.K. Bezrodny, A. Galan Energy and Power
Generation Technologies 2011;(2):16e9.
[7] Fialko NM. The estimation of heat pump using efficiency under metropolitans and coal
mine conditions. N.M. Fialko, Z.B. Zimin Industrial Heat Technique 2006;(2):111e9.
[8] Sorokin OA. The use of heat pump units for combined low potential heat utilization at
thermal power stations. O.A. Sorokin Industrial Power Engineering 2005;(6):36e41.
[9] Nicolaev YE. The determination of heat pump efficiency using the. Heat of Recycling
Power Engineering 2007;(9):14e7.
[10] Zimin LB. The analyses of heat pump system of sewer drain heat utilization for heat supply
of social objects. L.B. Zimin, N.M. Fialko Industrial Heat Technique 2008;(1):77e85.
[11] Nekrasova OA. The investigation of heating heat-pump systems (a model approach). O.A.
Nekrasova, Ju.V. Sinyak Heat Power Engineering 1986;(11):30e4.
[12] Kostikov AO. The effect of soil heat state on the efficiency of a heat pump unit with the soil
heat-exchanger. A.O. KostiKov, D.H. Harlampidi Power Engineering: Economy, Tech-
nology, Ecology 2009;(1):32e40.
[13] The Heat Pump Centre. http://heatpumpingtechnologies.org/.
[14] The European Heat Pump Association. www.ehpa.org.