Development and validation of quasi-steady-state heat pump water heater model having stratified water tank and wrapped-tank condenser

In this paper the system of air-source heat pump water heater(ASHPWH) using R134A to get 75°C hot water is proposed. The experiments on the performance of ASHPWH are conducted in two typical conditions, one for 7°C dry bulb temperature and 6°C wet bulb temperature, the other for 20°C dry bulb temperature and 15°C wet bulb temperature. In addition the variations of the suction temperature, the exhaust temperature, the suction pressure, the exhaust pressure, the transient heat capacity, the input power and COPs with the changing of the hot water tank temperature are analyzed. The results show that 75°C hot water can be produced steadily and the COPs are 2.84 and 3.68 respectively in two different conditions, therefore the ASHPWH has good energy saving effect.

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Numerical Analysis of the Performance of Dual-Tank with Movable Baffle for Heat Pump Water Heater

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.331.88 ◽

2013 ◽

Vol 331 ◽

pp. 88-93

Author(s):

Li Zhong Yang ◽

Jie Wu ◽

Ya Cai Hu ◽

Rong Hua Hong

Keyword(s):

Heat Pump ◽

Cold Water ◽

Heating Temperature ◽

Hot Water ◽

Water Tank ◽

Nickel Steel ◽

Water Heater ◽

Heat Pump Water Heater ◽

New Type ◽

Water Tanks

The design of a new type of water tank for heat pump water heater is proposed. A movable baffle is set in the cylindrical water tank to prevent the mixture of hot and cold water in order to enable more hot water available for utilizing. The COP of the heat pump cycle increased due to the decrease of initial heating temperature, thus energy is saved. By numerical calculation, the performance of the new design is significantly better than previous water tanks. Comparing with the floating plate tank and common natural stratification tank, in the condition of water leaking 3% and Chrome-nickel steel wall, the available hot water efficiency of dual-tank with movable baffle is 40% and 50% higher and the energy consumption 12.3% and 13.9% lower. Moreover, little water leaking could increase the available hot water.

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A quasi-steady-state heat balance model of residential walls

Mathematical and Computer Modelling ◽

10.1016/s0895-7177(99)00167-3 ◽

1999 ◽

Vol 30 (7-8) ◽

pp. 103-112 ◽

Cited By ~ 1

Author(s):

M.A. Medina

Keyword(s):

Steady State ◽

Heat Balance ◽

Balance Model ◽

Quasi Steady State ◽

State Heat ◽

Steady State Heat

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Experimental study of an instantaneous-heating air source heat pump water heater with a temperature stratified water tank

Advances in Mechanical Engineering ◽

10.1177/1687814016671248 ◽

2016 ◽

Vol 8 (9) ◽

pp. 168781401667124 ◽

Cited By ~ 2

Author(s):

Mingjing Lei ◽

Hua Zhang ◽

Fang Wang ◽

Xiaokuan You

Keyword(s):

Experimental Study ◽

Heat Pump ◽

Water Tank ◽

Water Heater ◽

Air Source Heat Pump ◽

Heat Pump Water Heater

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Thermodynamic analysis of a direct expansion solar assisted heat pump water heater

Journal of Energy in Southern Africa ◽

10.17159/2413-3051/2015/v26i2a2205 ◽

2017 ◽

Vol 26 (2) ◽

pp. 110 ◽

Cited By ~ 2

Author(s):

Masoud Yousefi ◽

Misagh Moradali

Keyword(s):

Ambient Temperature ◽

Heat Pump ◽

Coefficient Of Performance ◽

Water Tank ◽

Direct Expansion ◽

Water Heater ◽

Domestic Water ◽

Heat Pump Water Heater ◽

Thermodynamic Performance ◽

Flat Plate Solar Collector

In this paper, the thermodynamic performance of a direct expansion solar assisted heat pump (DX-SAHP), which is used to heat domestic water from 20˚C to 45˚C, is theoretically investigated. The system includes a 3m2 single-cover flat plate solar collector, 0.150m3 water tank and 70m tube immersed in the water tank as a condenser. The effect of various parameters such as radiation on the collector surface, compressor speed and the ambient temperature on the coefficient of performance (COP) are calculated. Results show that obtained COP is considerably more than that of a conventional heat pump water heater when radiation on the collector is high. Also, increasing collector area and reducing compressor speed enhance COP. The same occurs when the ambient temperature increases. For instance, at an ambient temperature of 15˚C and 450 w/m2 irradiation on collector surface, the calculated COP was 6.37.

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