scholarly journals Experimental Study of a Novel Direct-Expansion Variable Frequency Finned Solar/Air-Assisted Heat Pump Water Heater

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jing Qin ◽  
Jie Ji ◽  
Wenzhu Huang ◽  
Hong Qin ◽  
Mawufemo Modjinou ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Ambient Temperature ◽  
Heat Pump ◽  
Operating Mode ◽  
Heating Time ◽  
Solar Irradiation ◽  
Variable Frequency ◽  
Direct Expansion ◽  
Water Heater ◽  
Heat Pump Water Heater

A novel direct expansion variable frequency finned solar/air-assisted heat pump water heater was fabricated and tested in the enthalpy difference lab with a solar simulator. A solar/air source evaporator-collector with an automatic lifting glass cover plate was installed on the system. The system could be operated in three modes, namely, air, solar, and dual modes. The effects of the ambient temperature, solar irradiation, compressor frequency, and operating mode on the performance of this system were studied in this paper. The experimental results show that the ambient temperature, solar irradiation, and operating mode almost have no effect on the energy consumption of the compressor. When the ambient temperature and the solar irradiation were increased, the COP was found to increase with decreasing heating time. Also, when the compressor frequency was increased, an increase in the energy consumption of the compressor and the heat gain of the evaporator were noted with a decrease in the heating time.

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

2017 ◽  
Vol 26 (2) ◽  
pp. 110 ◽  
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.

Energy Consumption Modeling of a Heat Pump System for Combined Space Conditioning and Residential Water Heating in a Typical Household in Quito, Ecuador

2016 ◽  
Author(s):  
Gabriel Agila ◽  
Guillermo Soriano
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Thermal Storage ◽  
Hot Water ◽  
Water Heating ◽  
Water Heater ◽  
Pump System ◽  
Detailed Model ◽  
Heat Pump Water Heater ◽  
Residential Water

This research develops a detailed model for a Water to Water Heat Pump Water Heater (HPWH), operating for heating and cooling simultaneously, using two water storage tanks as thermal deposits. The primary function of the system is to produce useful heat for domestic hot water services according to the thermal requirements for an average household (two adults and one child) in the city of Quito, Ecuador. The purpose of the project is to analyze the technical and economic feasibility of implementing thermal storage and heat pump technology to provide efficient thermal services and reduce energy consumption; as well as environmental impacts associated with conventional systems for residential water heating. An energy simulation using TRNSYS 17 is carried to evaluate model operation for one year. The purpose of the simulation is to assess and quantifies the performance, energy consumption and potential savings of integrating heat pump systems with thermal energy storage technology, as well as determines the main parameter affecting the efficiency of the system. Finally, a comparative analysis based on annual energy consumption for different ways to produce hot water is conducted. Five alternatives were examined: (1) electric storage water heater; (2) gas fired water heater; (3) solar water heater; (4) air source heat pump water heater; and (5) a heat pump water heater integrated with thermal storage.

Control strategy and experimental analysis of a direct-expansion solar-assisted heat pump water heater with R134a

Energy ◽  
2018 ◽  
Vol 145 ◽  
pp. 17-24 ◽  
Author(s):  
Xiangqiang Kong ◽  
Kailin Jiang ◽  
Shandong Dong ◽  
Ying Li ◽  
Jianbo Li
Keyword(s):  
Heat Pump ◽  
Control Strategy ◽  
Experimental Analysis ◽  
Direct Expansion ◽  
Water Heater ◽  
Heat Pump Water Heater

scholarly journals Effects of Ambient Parameters on the Performance of a Direct-Expansion Solar-Assisted Heat Pump with Bare Plate Evaporators for Space Heating

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Wenzhu Huang ◽  
Jie Ji ◽  
Mawufemo Modjinou ◽  
Jing Qin
Keyword(s):  
Relative Humidity ◽  
Ambient Temperature ◽  
Heat Pump ◽  
Solar Irradiance ◽  
Solar Irradiation ◽  
Space Heating ◽  
Direct Expansion ◽  
Ambient Conditions ◽  
Solar Simulator ◽  
Independent Effects

Research on the direct-expansion solar-assisted heat pump (DX-SAHP) system with bare plate evaporators for space heating is meaningful but insufficient. In this paper, experiments on a DX-SAHP system applying bare plate evaporators for space heating are conducted in the enthalpy difference lab with a solar simulator, with the ambient conditions stable. The independent effects of ambient temperature, solar irradiation, and relative humidity on the system performance are investigated. When ambient temperature changes as 5°C, 10°C, and 15°C, COP increases as 2.12, 2.18, and 2.26. When solar irradiance changes as 0 W m−2, 100 W m−2, 200 W m−2, 300 W m−2, and 500 W m−2, COP of the system changes as 2.07, 2.09, 2.14, 2.26, and 2.36. With ambient temperature of 5°C and solar irradiance of 0 W m−2, when relative humidity is 50%, no frost formed. Whereas with relative humidity of 70% and 90%, frost formed but not seriously frosted after 120 min of operating. Frost did not deteriorate but improved the heating performance of the DX-SAHP system. The change of relative humidity from 70% to 90% improves the evaporating heat exchange rate by 35.0% and increases COP by 16.3%, from 1.78 to 2.07.

Statistical Analyses on Usage of Water Heater in Urban Residential Buildings

2014 ◽  
Vol 521 ◽  
pp. 748-751
Author(s):  
Zhao Xia Zhou
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Residential Buildings ◽  
Water Heater ◽  
Water Heaters ◽  
Heat Pump Water Heater ◽  
Initial Cost ◽  
The Common ◽  
The Cost ◽  
Residential Water

A survey for water heater in urban residential buildings is carried in Wuhan. The results show that more than 40% subjects use solar energy water heat. More than 20% subjects point out the energy consumption of water heater should be decreased. There are about 24.8% subjects take initial cost as the first place when they chose water heater. 44.2% subjects know about heat pump water heater, but they could not buy it if the initial cost is too high. There are 84% subjects could select heat pump water heater when the cost is no more 20% high than the average price of the common water heaters. Moreover, the energy consumptions of residential water heaters are also investigated. The energy consumption characteristics of water heater in Wuhan are analyzed.

scholarly journals Heat Pump Water Heater For Cold Climate – Canada

2021 ◽  
Author(s):  
Afarin Amirirad
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Residential Buildings ◽  
Minimum Energy ◽  
Cold Climate ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Water Heater ◽  
Domestic Hot Water ◽  
Heat Pump Water Heater

Considering the large energy consumption of conventional water heaters in residential buildings, the performance of a new type of water heater has been characterized through conducting experiments and numerical modelling. The specific water heater investigated in this work benefits from heat absorption from the indoor air, denoted as the air source heat pump water heater (ASHPWH), and is located in the Archetype Sustainable Twin House B in Toronto. The experiments have been conducted under three different indoor conditions associated with temperature and humidity. The coefficient of performance (COP), which quantifies the ratio of heating capacity to the consumed power of ASHPWH, ranges between 1.5 and 5, depending on the indoor dry bulb and water inlet temperatures. A TRNSYS model of ASHPWH has been constructed based on the obtained experimental results and has subsequently been integrated with a TRNSYS model of the Archetype Sustainable House (ASH). The numerical results were verified with the experimental data. The model results suggests that after employing ASHPWH, the domestic hot water energy consumption reduces by 60.3% and 53.2% compared to the electric water heater in summer and winter respectively. Due to the energy absorption of ASHPWH from the indoor environment, the heating load of the ASH house increases while its cooling load decreases. Furthermore, the annual electricity consumption of the ASH house due to the required heating and cooling as well as the domestic hot water demand is reduced by 21.3%. Finally, as a consequence of employing ASHPWH, the energy cost and GHG emission were reduced respectively by 22% and 21.7%. By investigating the system in four other Canadian cities, it appears that Vancouver and Edmonton would have the maximum and minimum energy savings respectively.

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