scholarly journals Thermodynamic Analysis of a Novel Space Heating System Featuring Hot Gas Water Technology

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Robbe Reykers ◽  
Raf Keersmaekers ◽  
Nesrin Ozalp ◽  
Johan Collaert
Keyword(s):  
Water Temperature ◽  
Experimental Testing ◽  
Operating Cost ◽  
Heating System ◽  
Hot Water ◽  
Space Heating ◽  
Efficiency Gain ◽  
Environmental Footprint ◽  
Source Temperature ◽  
Hot Gas

Low operating cost, comfort, sustainability, and environmental footprint are the key elements of robust space heating (SH) system. In quest for higher efficiencies, it is not always possible to meet all of these demands where environmental footprint often gets secondary attention. This paper presents a novel SH system which is capable of meeting all of the aforementioned elements while simultaneously proving SH and domestic hot water (DHW). The system comprises a geothermal sourced heat pump (HP) featuring “hot gas water” (HGW) technology which delivers higher efficiency. This paper gives a thorough thermodynamic assessment of the system covering component based first and second law analysis and provides test results based on two case studies at a house (W10/W35) and a renovated building (W10/W45). The results show that a theoretical efficiency gain by 11.02% is achievable where the source temperature is 10 °C and the water temperature for floor heating is 35 °C. For the same system, with the same source temperature but with a supply temperature of 45 °C for SH, an efficiency gain of 17.91% is achievable. From experimental testing of the system using the test stand at GeoTherma, 4.73% efficiency gain with water temperature of 35 °C and 3.59% efficiency gain with water temperature of 45 °C were obtained. Economic analysis results showed that savings of up to 10% on an annual basis is possible with HGW technology installed in an average family house, whereas it gets 4.36% for a small hotel with a payback time period of about 9 yrs.

Combined Space-Heating/Water-Heating System Performance

2001 ◽  
Author(s):  
Evelyn Baskin ◽  
John Spears
Keyword(s):  
Energy Use ◽  
Operating Cost ◽  
Heating System ◽  
Hot Water ◽  
Space Heating ◽  
Water Heating ◽  
Fuel Prices ◽  
Actual Usage ◽  
Heating Performance ◽  
One Year

Abstract With increasing fuel prices, various energy-saving techniques have been considered for residential appliances. Space heating accounts for the largest energy use in residential applications. One method proposed by manufacturers to keep operating cost low is to combine residential water-heating and space-heating functions into a single system. This paper presents the field test results of the performance of a combined water-heating/space-heating system under actual usage conditions. The system was installed in an 1187 ft2 (110 m2) home (Green Home) located in the Washington DC area. Data were collected for a one-year period. The water-heating performance was established by evaluating the hot water usage data during the test period. Water-heating/space-heating performance was established by using hot water data plus the amount of hot water circulated for space heating during the winter months. Analysis of the data indicated that the system produces hot water at an efficiency averaging 48% for water heating in the summer months and produces hot water at an efficiency ranging between 63.5–69.4% for combined water-heating/space-heating during the winter months. The relative humidity was maintained in the home at substantially lower level than that of the outside air, and the inside temperature was kept at the desired setting.

scholarly journals Overview of Solutions for the Low-Temperature Operation of Domestic Hot-Water Systems with a Circulation Loop

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3350
Author(s):  
Theofanis Benakopoulos ◽  
William Vergo ◽  
Michele Tunzi ◽  
Robbe Salenbien ◽  
Svend Svendsen
Keyword(s):  
Low Temperature ◽  
Heat Loss ◽  
District Heating ◽  
Heating System ◽  
Hot Water ◽  
Heating Power ◽  
Circulation Loop ◽  
Space Heating ◽  
District Heating System ◽  
Domestic Hot Water

The operation of typical domestic hot water (DHW) systems with a storage tank and circulation loop, according to the regulations for hygiene and comfort, results in a significant heat demand at high operating temperatures that leads to high return temperatures to the district heating system. This article presents the potential for the low-temperature operation of new DHW solutions based on energy balance calculations and some tests in real buildings. The main results are three recommended solutions depending on combinations of the following three criteria: district heating supply temperature, relative circulation heat loss due to the use of hot water, and the existence of a low-temperature space heating system. The first solution, based on a heating power limitation in DHW tanks, with a safety functionality, may secure the required DHW temperature at all times, resulting in the limited heating power of the tank, extended reheating periods, and a DH return temperature of below 30 °C. The second solution, based on the redirection of the return flow from the DHW system to the low-temperature space heating system, can cool the return temperature to the level of the space heating system return temperature below 35 °C. The third solution, based on the use of a micro-booster heat pump system, can deliver circulation heat loss and result in a low return temperature below 35 °C. These solutions can help in the transition to low-temperature district heating.

Calculation and Analysis of Gravity Head Coefficient in Hot Water Heating System

2014 ◽  
Vol 580-583 ◽  
pp. 2432-2437
Author(s):  
Wen Wen Xie ◽  
Yong Zheng Fu
Keyword(s):  
Water Temperature ◽  
Mathematical Expectation ◽  
Heating System ◽  
Hot Water ◽  
Heating Period ◽  
Water Heating ◽  
Average Value ◽  
Return Water ◽  
Regulation Mode

This paper presented a method of mathematical expectation to calculate gravity head coefficient, and this method was applied to calculate the value of gravity head coefficient of some selected cities in China in different operation regulation mode and different design supply and return water temperature. The results show that gravity head coefficient calculated by this method reflects the average value during the whole heating period. It has more representative significance. When the temperature of design supply and return water in heating system is reduced, the gravity head coefficients change very little. In different operation regulation modes, the gravity head coefficients change larger. The gravity head coefficients have a certain difference in different areas.

Theoretical Comparison of Solar Water/Space-Heating Combi Systems and Stratification Design Options

2007 ◽  
Vol 129 (4) ◽  
pp. 438-448 ◽  
Author(s):  
E. Andersen ◽  
S. Furbo
Keyword(s):  
Thermal Performance ◽  
International Energy Agency ◽  
Heating System ◽  
System Size ◽  
Hot Water ◽  
Weather Data ◽  
Space Heating ◽  
Energy Agency ◽  
Operation Conditions ◽  
Heating And Cooling

A theoretical analysis of differently designed solar combi systems is performed with weather data from the Danish Design Reference Year (55 deg N). Three solar combi system designs found on the market are investigated. The investigation focuses on the influence of stratification on the thermal performance under different operation conditions with different domestic hot water and space heating demands. The solar combi systems are initially equipped with heat exchanger spirals and direct inlets to the tank. A step-by-step investigation is performed demonstrating the influence on the thermal performance of using inlet stratification pipes at the different inlets. Also, how the design of the space heating system, the control system of the solar collectors, and the system size influence the thermal performance of solar combi systems are investigated. The work is carried out within the Solar Heating and Cooling Programme of the International Energy Agency (IEA SHC), Task 32.

The Energy-Saving and Carbon Emission Analysis of Solar-Assisted Air Source Heat Pump System for Hot Water Supply

2015 ◽  
Vol 799-800 ◽  
pp. 1440-1444
Author(s):  
Yuan Yu ◽  
Ke Zhi Yu ◽  
Hai Zhang
Keyword(s):  
Energy Consumption ◽  
Carbon Emission ◽  
Operating Cost ◽  
Heating System ◽  
High Energy ◽  
Hot Water ◽  
Cost Comparison ◽  
Water Heating ◽  
Emission Analysis ◽  
Pump System

The innovation of solar water heating system of students living community in Shanghai Ocean University is illustrated in this paper. A new water heating system including solar, air source heat pumps and gas boiler is established owing to the high energy consumption of original system. The comprehensive energy consumption, carbon emission and operating cost comparison between the original and new system is analysed based on the measured water, power and natural gas consumption. The results show that the comprehensive energy consumption is reduced by about 27.5%, the carbon commission decreased by 6%, and the operating costs reduced by approximately 23.6%, which means the new hot water system is successful.

scholarly journals Impact of Domestic Hot Water Systems on District Heating Temperatures

Energies ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4694
Author(s):  
Tina Lidberg ◽  
Thomas Olofsson ◽  
Louise Ödlund
Keyword(s):  
Low Temperature ◽  
District Heating ◽  
Heating System ◽  
Hot Water ◽  
Space Heating ◽  
Circulation System ◽  
District Heating System ◽  
Domestic Hot Water ◽  
Temperature Levels ◽  
The Impact

When buildings become more energy effective, the temperature levels of district heating systems need to be lower to decrease the losses from the distribution system and to keep district heating a competitive alternative on the heating market. For this reason, buildings that are refurbished need to be adapted to suit low-temperature district heating. The aim of this paper is to examine whether four different energy refurbishment packages (ERPs) can be used for lowering the temperature need of a multi-family buildings space heating and domestic hot water (DHW) system as well as to analyse the impact of the DHW circulation system on the return temperature. The results show that for all ERPs examined in this study, the space heating supply temperature agreed well with the temperature levels of a low-temperature district heating system. The results show that the temperature need of the DHW system will determine the supply temperature of the district heating system. In addition, the amount of days with heating demand decreases for all ERPs, which further increases the influence of the DHW system on the district heating system. In conclusion, the DHW system needs to be improved to enable the temperature levels of a low-temperature district heating system.

Geothermal Hot Water and Space Heating System in Egypt

2010 ◽  
Vol 7 (7) ◽  
pp. 1-14
Author(s):  
H. Farghally ◽  
F. Fahmy ◽  
M. EL-Sayed
Keyword(s):  
Heating System ◽  
Hot Water ◽  
Space Heating

Research on Composite System of Solar Energy Reclaimed Water Heat Pump and Phase Change Energy Storage

2014 ◽  
Vol 521 ◽  
pp. 56-59
Author(s):  
Hui Xing Li ◽  
Peng Cheng ◽  
Guo Hui Feng ◽  
Ran Zhang
Keyword(s):  
Heat Pump ◽  
Operating Cost ◽  
Reclaimed Water ◽  
Water Source ◽  
Heating System ◽  
Hot Water ◽  
Water Heating ◽  
Pump System ◽  
Heat Pump System ◽  
Important Approach

New energy development and utilization is an important approach to solve the problem of energy shortage,a new type of composite heating system is proposed in this study. It expounds the research ideas, the technical principle and operation plan of the system. Through a comparative analysis of the performance coefficient of composite heating system, reclaimed water source heat pump system and solar hot water heating system, it Comes to the conclusions that the composite heating system can not only reduce the operating cost but also improve the running performance of reclaimed water source heat pump and reduce the heat loss of solar hot water heating system.

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