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.

Solar-Assisted Heat Pump Systems: A Review of Existing Studies and Their Applicability to the Canadian Residential Sector

2013 ◽  
Author(s):  
Jenny Chu ◽  
Cynthia A. Cruickshank
Keyword(s):  
Heat Pump ◽  
Residential Buildings ◽  
International Energy Agency ◽  
Heat Pumps ◽  
Hot Water ◽  
Performance Criteria ◽  
Space Heating ◽  
Residential Sector ◽  
Heating And Cooling ◽  
System Configurations

Heat pumps are commonly used for space-heating and cooling requirements. The combination of solar thermal and heat pump systems as a single solar-assisted heat pump (SAHP) system is a promising technology for offsetting domestic hot water, space-heating and cooling loads more efficiently. Task 44 of the Solar Heating and Cooling Programme of the International Energy Agency is currently investigating ways to optimize SAHP systems for residential use. This paper presents a review of past and current work conducted on SAHP systems. Specifically, the key performance data from many studies are highlighted and different system configurations are compared in order to establish insight towards which system configurations are suitable for the Canadian residential sector. It was found that the most suitable configuration for Canadian residential buildings depend on a combination of factors which may include occupant behavior, building characteristics, operation parameters, system components, the performance criteria of interest and climate. A large variety of configurations and parameters exist for SAHP systems and this made analyzing a specific system, comparing differing systems and establishing an optimal design fairly difficult. It was found that different authors used various different performance criterions and this inconsistency also added to the difficulty of comparing the studies of different systems. Overall, a standard performance criterion needs to be established for SAHP systems in order to meaningfully compare different configurations and determine optimal configurations for certain requirements.

An Hourly Building Simulation Model Aimed at Fuel Cell Applications

2006 ◽  
Author(s):  
Hugh I. Henderson ◽  
Bharathkrishna Karambakkam ◽  
Jeffrey Boyer ◽  
Rhonda Staudt
Keyword(s):  
Fuel Cell ◽  
Simulation Model ◽  
New York State ◽  
Hot Water ◽  
Building Simulation ◽  
Weather Data ◽  
Space Heating ◽  
Simulation Tool ◽  
Water Heating ◽  
Heating And Cooling

The successful widespread adoption of fuel cell systems is highly dependent upon the economics of the installation. This entails closely matching system capabilities with customer requirements. System sizing requires accurate predictions of building thermal and electrical loads. The TRNSYS-based building simulation model presented in this paper was developed to accurately integrate a fuel cell into the space heating, water heating, and cooling equipment in a building. The simulation tool determines water heating, space heating, and cooling loads for a single zone building on an hour-by-hour basis throughout the year using TMY2 weather data. It integrates empirical and theoretical state point models of the components of a fuel cell-based cogeneration and tri-generation system as well as baseline HVAC technologies. The key components include: hot water loops, stratified water tanks, boilers, furnaces, air conditioners, absorption chillers, space conditioning coils, heat rejection equipment, and ventilation controls. Various control options are incorporated to maintain setpoints, stage equipment, and limit power export. Renewable power systems such as PV and wind are also integrated into the model. The TRNSYS calculation engine iterates to find the state of the system for each hour. The simulation tool also includes post-processing capabilities to apply complex electric tariffs, organize annual simulation results, and manage multiple parametric runs. The tool has been developed to optimize the configuration of a fuel cell in a given building application and to complete numerous parametric runs to evaluate the economics of a system in different locations and building applications. This work was funded in part by the New York State Energy Research and Development Authority.

The Role of Passive Solar Design on Peak and Annual Heating and Cooling Loads in Office Buildings in Mexico

2009 ◽  
Author(s):  
Ani´bal Figueroa ◽  
Victor Fuentes ◽  
Gloria Castorena
Keyword(s):  
International Energy Agency ◽  
Peak Load ◽  
Central Area ◽  
Cost Effective ◽  
System Size ◽  
Temperate Climate ◽  
Cooling Load ◽  
Energy Agency ◽  
Heating And Cooling ◽  
The Impact

According to the International Energy Agency in 2006 nearly 36% of the total world energy was consumed by buildings and urbanization. This paper dimensions the effect of passive design corrections on the envelope of a new corporate office building in the temperate climate of Mexico City’s central area. It confirms that these are the most cost effective measures to reduce HVAC peak load, minimize system size and improve performance. It used thermal analysis to evaluate the impact of three corrective strategies: low E double glassing, adjusting shading coefficient (SC) and insulation of walls and ceiling. Results show that if low E double glassed windows are installed, heating requirements are cut by half, while peak cooling load is reduced one fifth. A 50% Shading Coefficient (SC) has also a significant effect, reducing peak cooling load in May an additional 26%.

Solar-Assisted Heat Pump Systems: A Review of Existing Studies and Their Applicability to the Canadian Residential Sector

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
Jenny Chu ◽  
Cynthia A. Cruickshank
Keyword(s):  
Heat Pump ◽  
Residential Buildings ◽  
International Energy Agency ◽  
Heat Pumps ◽  
Hot Water ◽  
Specific System ◽  
Energy Agency ◽  
Residential Sector ◽  
Heating And Cooling ◽  
System Configurations

Combining solar thermal collectors and heat pumps into a single solar-assisted heat pump (SAHP) system is a promising technology for offsetting domestic hot water (DHW), space-heating, and cooling loads more efficiently. Task 44 of the Solar Heating and Cooling (SHC) Programme of the International Energy Agency (IEA) is currently investigating ways to optimize solar and heat pump systems for residential use. This paper presents a review of past and current work conducted on SAHP systems. Specifically, the key performance data from many studies are highlighted and different system configurations are compared in order to establish insight toward which system configurations are suitable for the Canadian residential sector. It was found that the most suitable configuration for Canadian residential buildings depends on a combination of factors which include occupant behavior, building characteristics, operation parameters, system components, and climate. A large variety of configurations and parameters exist and this made analyzing a specific system, comparing differing systems and establishing an optimal design difficult. It was found that different authors used different performance criterion and this inconsistency also added to the difficulty of comparing the studies of different systems.

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.

scholarly journals Development of a hybrid solar cascade heat pump heating system

2021 ◽  
Author(s):  
Jamie Fine
Keyword(s):  
Case Studies ◽  
Co2 Emissions ◽  
Heat Pump ◽  
Thermal Performance ◽  
Heating System ◽  
Solar Heating ◽  
Hot Water ◽  
Solar Irradiation ◽  
Solar Still ◽  
Evacuated Tube

Society’s use of fossil fuels has led to increasingly high levels of CO2 in the atmosphere. These levels have been linked to global average temperature rises, and increases in the severity and frequency of major weather events. To combat these effects, nations around the world have committed to reducing their CO2 emissions, and transition to renewable energy. This thesis focuses on the development of a novel solar heating system, which combines a hybrid solar panel and cascade heat pump. The thesis begins by presenting a high-level literature review of solar and heat pump technologies, followed by the initial design development of the system. Two design iterations are presented, illustrating that the final design was selected because it exhibits improved peak heat output, and reduced sensitivity to panel temperature. Next, a manuscript-based chapter is presented that focuses on utilizing the proposed solar heating system for water distillation. Case studies are presented that compare the performance of the proposed system with a solar still at four different locations. The final conclusion from these studies is that using the proposed system offers area-based performance improvements of 780% compared to a basic solar still. A second manuscript-based study is then presented, which focuses on utilizing the proposed solar heating system for domestic hot water production. Additional case studies are detailed that compare the proposed system to an evacuated tube design, and a single heat pump. The conclusions from these studies are that the proposed system exceeds the performance of the evacuated tube system by up to 64%, and that the proposed system is most beneficial during seasons with higher average dry-bulb temperatures, and increased solar irradiation. A final manuscript-based study is then presented, which focuses on a methodology for improving alternate mode thermal performance estimates for hybrid solar panels. The conclusion from this study is that the proposed methodology can successfully estimate thermal performance within 5% of actual values. Each of these studies contributes to the project goal of developing a novel solar energy heating system, which can be further developed to reduce global CO2 emissions, and reduce the effects of climate change.

scholarly journals Development of a hybrid solar cascade heat pump heating system

2021 ◽  
Author(s):  
Jamie Fine
Keyword(s):  
Case Studies ◽  
Co2 Emissions ◽  
Heat Pump ◽  
Thermal Performance ◽  
Heating System ◽  
Solar Heating ◽  
Hot Water ◽  
Solar Irradiation ◽  
Solar Still ◽  
Evacuated Tube

Society’s use of fossil fuels has led to increasingly high levels of CO2 in the atmosphere. These levels have been linked to global average temperature rises, and increases in the severity and frequency of major weather events. To combat these effects, nations around the world have committed to reducing their CO2 emissions, and transition to renewable energy. This thesis focuses on the development of a novel solar heating system, which combines a hybrid solar panel and cascade heat pump. The thesis begins by presenting a high-level literature review of solar and heat pump technologies, followed by the initial design development of the system. Two design iterations are presented, illustrating that the final design was selected because it exhibits improved peak heat output, and reduced sensitivity to panel temperature. Next, a manuscript-based chapter is presented that focuses on utilizing the proposed solar heating system for water distillation. Case studies are presented that compare the performance of the proposed system with a solar still at four different locations. The final conclusion from these studies is that using the proposed system offers area-based performance improvements of 780% compared to a basic solar still. A second manuscript-based study is then presented, which focuses on utilizing the proposed solar heating system for domestic hot water production. Additional case studies are detailed that compare the proposed system to an evacuated tube design, and a single heat pump. The conclusions from these studies are that the proposed system exceeds the performance of the evacuated tube system by up to 64%, and that the proposed system is most beneficial during seasons with higher average dry-bulb temperatures, and increased solar irradiation. A final manuscript-based study is then presented, which focuses on a methodology for improving alternate mode thermal performance estimates for hybrid solar panels. The conclusion from this study is that the proposed methodology can successfully estimate thermal performance within 5% of actual values. Each of these studies contributes to the project goal of developing a novel solar energy heating system, which can be further developed to reduce global CO2 emissions, and reduce the effects of climate change.

Architecture Design of Building Integrated Solar Collector

2014 ◽  
Vol 889-890 ◽  
pp. 1333-1336
Author(s):  
Yu Fu ◽  
Kai Chen ◽  
Fei Ying Fu ◽  
Xin Bin Wang
Keyword(s):  
Water Supply ◽  
Solar Collector ◽  
Residential Buildings ◽  
Radiation Energy ◽  
Hot Water ◽  
Space Heating ◽  
Solar Collectors ◽  
Domestic Hot Water ◽  
Heating And Cooling ◽  
Hot Water Supply

Solar thermal collector converts solar radiation energy into useful thermal energy and transfers to a transport fluid flowing through the system. The collected energy can be used either direct to space or water heating equipment, or to a thermal storage for later use. Along with fast development, not only domestic hot water supply is needed, but also space heating and cooling are required. Also, limited roof space is another key barrier that should be considered. Furthermore, most of the building integration with solar collectors are mounted on the roof top by flat or tilt angle at present. It is considered to be a failure of low level architectural quality because the collector is used only for application and seems as an independent technical element of the building. With the consideration of the above, novel type of solar collector has been proposed to realize the utilization and offset the barriers. This novel solar collectors is especially suitable to supply domestic hot water, and combines with ASHP for multi-function, space heating and cooling as well as domestic hot water supply. Additionally, it is well integrated with high-rise residential buildings, which is good for aesthetic.

Simulation Study on Solar Collector - Air Source Heat Pump Combined System for Space Heating in Cold Region

2012 ◽  
Vol 238 ◽  
pp. 478-481
Author(s):  
Zhen Qing Wang ◽  
Yan Chen ◽  
Hai Xia Wang
Keyword(s):  
Heat Pump ◽  
Simulation Study ◽  
Hot Water ◽  
Office Building ◽  
Space Heating ◽  
Combined System ◽  
Pump System ◽  
Heat Pump System ◽  
Heating And Cooling ◽  
Air Source Heat Pump

An air source heat pump system (ASHPS) was set up, which provided space heating and cooling, as well as hot water for an office building in Tianjin. Its operating performance in winter was evaluated based on test data. Considering the local abundant solar radiation and the way to provide energy in an office building, a simulation study was carried out on the combsystem of ASHP and flat plate air collector (FPAC). The effects of collector area and its outlet parameters on the heating performance of ASHP were studied, and the favorable operating and matching mode were recommended. The results indicate that ASHPS is a technically viable method in Tianjin in winter, but not economically, and the air-solar combsystem should be taken into account for its massive replacement for conventional energy.

scholarly journals Modelling and testing a passive night-sky radiation system

2017 ◽  
Vol 28 (1) ◽  
pp. 76 ◽  
Author(s):  
G.D. Joubert ◽  
R.T. Dobson
Keyword(s):  
Storage Tank ◽  
Cold Water ◽  
Water Storage ◽  
Heating System ◽  
Hot Water ◽  
Theoretical Simulation ◽  
Water Storage Tank ◽  
Heating And Cooling ◽  
Night Sky ◽  
Radiation Cooling

The as-built and tested passive night-sky radiation cooling/heating system considered in this investigation consists of a radiation panel, a cold water storage tank, a hot water storage tank, a room and the interconnecting pipework. The stored cold water can be used to cool a room during the day, particularly in summer. A theoretical time-dependent thermal performance model was also developed and compared with the experimental results and it is shown that the theoretical simulation model captures the experimental system performance to within a reasonable degree of accuracy. A natural circulation experimental set-up was constructed and subsequently used to show that under local (Stellenbosch, South Africa) conditions the typical heat-removal rate from the water in the tank is 55 W/m2 of radiating panel during the night; during the day the water in the hot water-storage tank was heated from 24 °C to 62 °C at a rate of 96 W/m2. The system was also able to cool the room at a rate of 120 W/m3. The results thus confirmed that it is entirely plausible to design an entirely passive system, that is, without the use of any moving mechanical equipment such as pumps and active controls, for both room-cooling and water-heating. It is thus concluded that a passive night-sky radiation cooling/heating system is a viable energy-saving option and that the theoretical simulation, as presented, can be used with confidence as an energy-saving system design and evaluation tool. Keywords: passive cooling and heating, buoyancy-driven fluid flow, theoretical simulation, experimental verification Highlights:Passively driven renewable energy heating and cooling systems are considered.Time-dependent mathematical simulation model is presented.Experimental buoyancy-driven heating and cooling system built and tested.Experimental results demonstrate the applicability of the theoretical simulation model.Saving and evaluation design tool.

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