scholarly journals The Performance of an ASHP System Using Waste Air to Recover Heat Energy in a Subway System

2019 ◽  
Vol 1 (1) ◽  
pp. 154-163 ◽  
Author(s):  
Konstantinos Ninikas ◽  
Nicholas Hytiris ◽  
Rohinton Emmanuel ◽  
Bjorn Aaen
Keyword(s):  
Heat Pump ◽  
Air Temperature ◽  
Short Communication ◽  
Heat Energy ◽  
Coefficient Of Performance ◽  
Air Source Heat Pump ◽  
Lessons Learnt ◽  
Waste Air ◽  
Subway System

In this short communication, we demonstrate that the performance of a typical air source heat pump (ASHP), exploiting a relatively stable air temperature within a subway environment, is high, even during the peak heating months. After a nine-month operational run, the coefficient of performance is demonstrated to be 3.5. The design and installation difficulties are stated together with the lessons learnt following this trial. The actual energy and carbon savings are discussed.

Experimental Investigation of Air-Source Heat Pump Heating System With a Novel Thermal Storage Refrigerant-Heated Panel

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Suola Shao ◽  
Huan Zhang ◽  
Shijun You ◽  
Yaran Wang
Keyword(s):  
Heat Pump ◽  
Air Temperature ◽  
Thermal Storage ◽  
Heating System ◽  
Economic Feasibility ◽  
Coefficient Of Performance ◽  
Total Annual Cost ◽  
Condensation Temperature ◽  
Outdoor Air ◽  
Air Source Heat Pump

Abstract In response to the triple crisis of energy–environment–economy (3Es), the air-source heat pump (ASHP) system is considered to be one of the most feasible candidates to upgrade the traditional high emission heating solutions. In this paper, a novel thermal storage refrigerant-heated panel (RHP) is proposed for the ASHP heating system. Experiments were conducted in a climate chamber to test the heating and defrosting performance of the system, the thermal performance of the RHP, the system energy efficiency, and the system economic feasibility. The results show that the heat flux of the RHP is as high as 625.5 W/m2 at a condensation temperature of 40 °C and an outdoor air temperature of −7 °C. Meanwhile, the system is demonstrated to be reliable and competitive with efficient thermal stability in heating conditions and comfortable indoor thermal in defrosting conditions. The coefficient of performance (COP) ranges from 2.2 to 4.0 when the outdoor air temperature changes from −12 °C to 7 °C in the tests. Meanwhile, the initial capital cost and the total annual cost of the proposed system are 430 USD and 203.1 USD, respectively, which is competitive in the distracted heating systems.

scholarly journals Impact of Compressor Drive System Efficiency on Air Source Heat Pump Performance for Heating Hot Water

2020 ◽  
Vol 12 (24) ◽  
pp. 10521
Author(s):  
Mariusz Szreder ◽  
Marek Miara
Keyword(s):  
Heat Pump ◽  
Air Temperature ◽  
Heating System ◽  
Operating Conditions ◽  
Drive System ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Air Source Heat Pump ◽  
Heating Capacity ◽  
The Impact

A standard Polish household with a central heating system powered by a solid fuel furnace was chosen as a case study. The modular Air Source Heat Pump (ASHP) was used to heat the hot water outside the heating season. In this article comparative studies of the impact of the compressor drive system used on the energy efficiency of the heat pump have been carried out in operating conditions. The ASHP heating capacity and coefficient of performance (COP) were determined for the outside air temperature in the range from 7 to 22 °C by heating the water in the tank to a temperature above 50 °C. For the case of a fixed speed compressor, average heating capacity in the range 2.7−3.1 kW and COP values in the range 3.2−4.6 depending on the evaporator supply air temperature were obtained. Similarly, for the inverter compressor, the average heating capacity in the range of 2.7−5.1 kW was obtained for the frequency in the range of 30–90 Hz and COP in the range 4.2−5.7, respectively. On cool days, the average heating capacity of the heat pump decreases by 12%. For the simultaneous operation of two compressors with comparable heating capacity, lower COP values were obtained by 20%.

scholarly journals Studying a Hybrid System Based on Solid Oxide Fuel Cell Combined With an Air Source Heat Pump and With a Novel Heat Recovery

2018 ◽  
Vol 16 (2) ◽  
Author(s):  
Giulio Vialetto ◽  
Marco Noro ◽  
Masoud Rokni
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Electric Power ◽  
Heat Pump ◽  
Heat Recovery ◽  
Research Work ◽  
Solid Oxide ◽  
Coefficient Of Performance ◽  
Oxide Fuel ◽  
Air Source Heat Pump

In this paper, a new heat recovery for a microcogeneration system based on solid oxide fuel cell and air source heat pump (HP) is presented with the main goal of improving efficiency on energy conversion for a residential building. The novelty of the research work is that exhaust gases after the fuel cell are first used to heat water for heating/domestic water and then mixed with the external air to feed the evaporator of the HP with the aim of increasing energy efficiency of the latter. This system configuration decreases the possibility of freezing of the evaporator as well, which is one of the drawbacks for air source HP in Nordic climates. A parametric analysis of the system is developed by performing simulations varying the external air temperature, air humidity, and fuel cell nominal power. Coefficient of performance (COP) can increase more than 100% when fuel cell electric power is close to its nominal (50 kW), and/or inlet air has a high relative humidity (RH) (close to 100%). Instead, the effect of mixing the exhausted gases with air may be negative (up to −25%) when fuel cell electric power is 20 kW and inlet air has 25% RH. Thermodynamic analysis is carried out to prove energy advantage of such a solution with respect to a traditional one, resulting to be between 39% and 44% in terms of primary energy. The results show that the performance of the air source HP increases considerably during cold season for climates with high RH and for users with high electric power demand.

scholarly journals Frosting Phenomenon and Frost-Free Technology of Outdoor Air Heat Exchanger for an Air-Source Heat Pump System in China: An Analysis and Review

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2642 ◽  
Author(s):  
Yi Zhang ◽  
Guanmin Zhang ◽  
Aiqun Zhang ◽  
Yinhan Jin ◽  
Ruirui Ru ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Heat Pump ◽  
Operating Cost ◽  
Heating System ◽  
Coefficient Of Performance ◽  
Outdoor Air ◽  
Pump System ◽  
Heat Pump System ◽  
Reduce Operating Cost ◽  
Air Source Heat Pump

Frost layer on the outdoor air heat exchanger surface in an air-source heat pump (ASHP) can decrease the system coefficient of performance (COP). Although the common defrosting and anti-frosting methods can improve the COP, the periodic defrosting not only reduces the system energy efficiency but also deteriorates the indoor environment. To solve these problems, it is necessary to clearly understand the frosting phenomenon and to achieve the system frost-free operation. This paper focused firstly on the analyses of frosting pathways and frosting maps. Followed by summarizing the characteristics of frost-free technologies. And then the performances of two types of frost-free ASHP (FFASHP) systems were reviewed, and the exergy and economic analysis of a FFASHP heating system were carried out. Finally, the existing problems related to the FFASHP technologies were proposed. Results show that the existing frosting maps need to be further improved. The FFASHP systems can not only achieve continuous frost-free operation but reduce operating cost. And the total COP of the FFASHP heating system is approximately 30–64% higher than that of the conventional ASHP system under the same frosting conditions. However, the investment cost of the FFASHP system increases, and its reliability also needs further field test in a wider frosting environment. In the future, combined with a new frosting map, the control strategy for the FFASHP system should be optimized.

Experimental Study on Performance Enhancement of Heat Pump With Screw Compressor

2004 ◽  
Author(s):  
Wu Huagen ◽  
Shu Pengcheng ◽  
Zhao Yuanyang ◽  
Xing Ziwen
Keyword(s):  
Heat Pump ◽  
Air Conditioning ◽  
Performance Enhancement ◽  
Coefficient Of Performance ◽  
Screw Compressor ◽  
Alternative Refrigerants ◽  
Air Source Heat Pump ◽  
Central Air Conditioning ◽  
Compressor Performance ◽  
Industrial Refrigeration

The air-source heat pump has been widely used in industrial refrigeration and central air-conditioning applications because of its unique superiority. An important consideration in the design of heat pump is improving its COP (coefficient of performance). In this paper, the results of experimental investigation on the effects of alternative refrigerants (R22, R134a, R404A and R407C) and economizer on the performance of heat pump are presented. The COP of the heat pump used R134a is up to 4.5% higher than R22, but its capacity got a 37.08% decrease. The refrigerant R407C applied in heat pump can improve the capacity up to 7.86% than R22, but its COP shows a decrease up to 5.92%. The refrigerant R404A used in heat pump will result in poor capacity and COP compared to R22. The economizer system used in heat pump will improve the COP, but as the superfeed pressure of the economizer increases, the system COP increases first, and then drops. So there exists an optimal superfeed pressure of the economizer for the best COP. Also, the effect of the economizer on the screw compressor performance is analyzed by recording the P-v indicator diagram.

scholarly journals Performance Analysis of Air-to-Water Heat Pump in Latvian Climate Conditions

2014 ◽  
Vol 14 (1) ◽  
pp. 18-22 ◽  
Author(s):  
Janis Kazjonovs ◽  
Andrejs Sipkevics ◽  
Andris Jakovics ◽  
Andris Dancigs ◽  
Diana Bajare ◽  
...  
Keyword(s):  
Heat Pump ◽  
Air Temperature ◽  
Residential Buildings ◽  
Winter Season ◽  
Pump Energy ◽  
Energy Performance ◽  
Coefficient Of Performance ◽  
Heating Period ◽  
Climate Conditions ◽  
Eu Directive

Abstract Strategy of the European Union in efficient energy usage demands to have a higher proportion of renewable energy in the energy market. Since heat pumps are considered to be one of the most efficient heating and cooling systems, they will play an important role in the energy consumption reduction in buildings aimed to meet the target of nearly zero energy buildings set out in the EU Directive 2010/31/EU. Unfortunately, the declared heat pump Coefficient of Performance (COP) corresponds to a certain outdoor temperature (+7 °C), therefore different climate conditions, building characteristics and settings result in different COP values during the year. The aim of this research is to investigate the Seasonal Performance factor (SPF) values of air-to-water heat pump which better characterize the effectiveness of heat pump in a longer selected period of time, especially during the winter season, in different types of residential buildings in Latvian climate conditions. Latvia has four pronounced seasons of near-equal length. Winter starts in mid-December and lasts until mid-March. Latvia is characterized by cold, maritime climate (duration of the average heating period being 203 days, the average outdoor air temperature during the heating period being 0.0 °C, the coldest five-day average temperature being −20.7 °C, the average annual air temperature being +6.2 °C, the daily average relative humidity being 79 %). The first part of this research consists of operational air-towater heat pump energy performance monitoring in different residential buildings during the winter season. The second part of the research takes place under natural conditions in an experimental construction stand which is located in an urban environment in Riga, Latvia. The inner area of this test stand, where air-to-water heat pump performance is analyzed, is 9 m2. The ceiling height is 3 m, all external wall constructions (U = 0.16 W/(m2K)) have ventilated facades. To calculate SPF, the experimental stand is equipped with sensors which provide measurements for electricity consumption and gained heat energy.

Air-water heat pump applied as water boiler in single-family house, coefficient of performance analysis under the real conditions

2018 ◽  
Vol 3 (2) ◽  
pp. 58-61
Author(s):  
Agnieszka Lisowska-Lis ◽  
Robert Leszczyński
Keyword(s):  
Heat Source ◽  
Heat Pump ◽  
Air Temperature ◽  
Electrical Energy ◽  
Coefficient Of Performance ◽  
Single Family ◽  
Pump System ◽  
Heat Pump System ◽  
System Temperature ◽  
Family House

The subject of the research was an air-water heat pump, model PCUW 2.5kW from HEWALEX, installed in a single-family house. The pump is only used for heating water. The research was carried out from 25-08-2017 to 18-09-2017 in the village of Zborowice, in Malopolska region, Poland. The data were recorded from the heat pump system: temperature of the lower heat source (external air), temperature of the upper heat source (water temperature in the tank), time of heat pump was calculated during the analysed cycle of work and electrical energy consumption. The Coefficient Of Performance (COP) of the analysed air-water heat pump was determined. The analysis of the results was carried out using the MATLAB and EXCEL statistical tools. The correlation between COP coefficient and external air temperature is strong: 0.67.

Analysis of Domestic Hot Water Production Efficiency for Detached Houses

2015 ◽  
Vol 797 ◽  
pp. 185-191
Author(s):  
Arkadiusz Gużda ◽  
Norbert Szmolke
Keyword(s):  
Heat Pump ◽  
Production Efficiency ◽  
Hot Water ◽  
Coefficient Of Performance ◽  
Water Production ◽  
Water Heater ◽  
Domestic Hot Water ◽  
Air Source Heat Pump ◽  
Heat Pump Water Heater ◽  
Detached House

The article compares two means for domestic hot water production (DHW) for a detached house that is using gas boiler with a closed combustion chamber and air source heat pump water heater (ASHPWH). An analysis of domestic hot water production using an air source heat pump was made taking into account coefficient of performance listed according to the new BS EN 16147 standard. The analysis of outlay related to the investment and operating costs was also performed. Ultimately, the more profitable choice for domestic hot water production was made.

Heating Performance Investigations on Two Applications of a Solar Assisted Air Source Heat Pump System

2011 ◽  
Vol 374-377 ◽  
pp. 284-287 ◽  
Author(s):  
Yu Wang ◽  
Yu Wen You ◽  
Zhi Gang Zhang
Keyword(s):  
Heat Pump ◽  
Solar Collector ◽  
Coefficient Of Performance ◽  
Experimental Investigations ◽  
Pump System ◽  
Heat Pump System ◽  
Heating Performance ◽  
Air Source Heat Pump

A solar assisted air source heat pump (SAASHP) system is proposed to improve heating performance of air source heat pump (ASHP).The proposed system has been applied in two buildings, a series of experimental investigations were conducted in the both applications, it indicated that the SAASHP system gets better heating performance than ASHP system, the coefficient of performance (COP) gets 10% and 65% increase respectively in two applications. It is also concluded that the ratio of solar collector area to construction area significantly affects the improvement of heating performance in SAASHP system. This work may promote further research and more applications of SAASHP system.

An Investigation of Energy Consumption, Solar Fraction and Hybrid Photovoltaic–Thermal Solar Dryer Parameters in Drying of Chamomile Flower

2014 ◽  
Vol 10 (4) ◽  
pp. 697-711 ◽  
Author(s):  
Saeid Minaei ◽  
Ali Motevali ◽  
Barat Ghobadian ◽  
Ahmad Banakar ◽  
Seyed Hashem Samadi
Keyword(s):  
Energy Consumption ◽  
Heat Pump ◽  
Air Temperature ◽  
Coefficient Of Performance ◽  
Pump Mode ◽  
Energy Fraction ◽  
Drying Time ◽  
Solar Dryer ◽  
Drying Behavior ◽  
Chamomile Flower

Abstract In this research, drying of a medicinal plant (chamomile) in a hybrid photovoltaic–thermal solar dryer with and without heat pump was investigated. The experiments were performed at three air speeds (0.5, 1, and 1.5 m/s), three levels of air temperature (40, 50, and 60°C), with and without using a heat pump. Results of analysis indicated that adding a heat pump to the photovoltaic solar dryer decreases drying time, energy consumption, and required specific energy. Solar energy fraction increased with decreasing air temperature and velocity. Analysis of the dryer-related parameters showed that the maximum and minimum thermal efficiencies were 33.8 and 16.4%, respectively, both in the no-heat-pump mode while with the heat pump, its maximum and minimum values were 38.4 and 19.7%, respectively. Moreover, the highest and lowest electrical efficiencies for the no-heat-pump mode were 13.4 and 9.1%, respectively; while using the heat pump, its maximum and minimum values were 14.1 and 10.4%, respectively. Results of analyzing the dryer’s coefficient of performance for drying chamomile showed that the highest and lowest coefficients of performance were 3.41 and 1.82, respectively. Eleven mathematical models were tested, and Page’s model was selected as the best for describing the drying behavior of chamomile flower.

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