Top PDF Performance analysis of ground source heat pumps for buildings applications

Performance analysis of ground source heat pumps for buildings applications

Performance analysis of ground source heat pumps for buildings applications

Geothermal heat pumps (GSHPs), or direct expansion (OX) ground source heat pumps, are a highly efficient renewable energy technology, which uses the earth, groundwater or surface water a[r]

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Experimental Performance Analysis of Ground Source Heat Pumps (GSHPs)

Experimental Performance Analysis of Ground Source Heat Pumps (GSHPs)

Abstract Ground Source Heat Pumps (GSHP) have become as one of the most indispensable cooling and heating systems in residential applications since they have higher energy efficiency compared to the other conventional alternatives all around the world. In this study, a ground source heat pump system (GSHP) with the heat package unit model of GT018 FHP Manufacturing Co., was installed. The system setup included polyethylene U-bend ground heat exchanger pipes, nine drilled wells, and the pipes buried in soil at 15 m depth and in the cooling season of 2013. The system was tested, and its performance was reported. By the meteorological data, the values of humidity variations, air temperature, wells and water temperatures, relative humidity, and the system power supply were measured continuously for three months. The results showed that the adoption of GSHP system created a stable room indoor temperature of 25°C to 28°C. Furthermore, a great energy saving happened in the process, and the average coefficient of performance (COP) of 4.76 was achieved for the system that shows a suitable design and installation process.
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Performance analysis of air source heat pumps using detailed simulations and comparison to field trial data

Performance analysis of air source heat pumps using detailed simulations and comparison to field trial data

Whilst there is an extensive literature on the performance of ground source heat pumps in the domestic sector (e.g. Healy and Ugursal [1997], Kummert and Bernier [2008] in Canada; and Underwood and Spitler [2007], Jenkins et. al. [2009a] in the UK) the literature on ASHP performance is far more sparse. Most modelling work focuses on specific aspects of device performance (e.g. Lui et al [2003], Yao [2004]) rather than integrated performance. In those performance studies that exist, Cockroft and Kelly (2006) used a low-resolution model to determine that in a UK context ASHPs could achieve significant carbon savings in comparison to the domestic heating technologies, including condensing gas boilers. Jenkins et al. (2009b) looked at the carbon savings potential of ASHP in office buildings and concluded that the technology did not guarantee emissions savings under all circumstances; this study used a performance map model of the ASHP and hourly predictions of heating and cooling from a simulation tool.
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Dynamic thermal modelling of horizontal ground source heat pumps

Dynamic thermal modelling of horizontal ground source heat pumps

A ground-source heat pump is a sustainable technology for heating and cooling of buildings by making use of earth or ground water as the heat source or sink through a heat exchan- ger. It has lower running costs than a conventional heating and air-conditioning system and is more efficient than an air-source heat pump because of the relatively stable temperature of deep soil, but it is more expensive to install the ground-coupled heat exchanger. A heat exchanger is required to transfer heat between the fluid within the heat exchanger and surrounding soil for a ground-coupled heat pump. The heat exchanger can be installed vertically or horizontally. A horizontally coupled ground-source heat pump makes use of principally solar heat stored in the shallow soil, whereas a vertically coupled ground-source heat pump uses geothermal energy from the earth. A horizontally coupled heat exchanger is cheaper, but requires more land/area to install than a vertical borehole heat exchanger. Besides, the former needs to be longer than the latter for the same heat transfer rate because ambient conditions can have an adverse effect on the short-term performance of a horizontally coupled ground-source heat pump. However, this apparent disadvantage of a horizontally coupled heat pump can in a way become an advantage for long-term operation. Different heat transfer mechanisms between the ambient and ground surface including solar heat gains and heat losses/gains due to long-wave
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Study and Experimental Analysis of Horizontal Ground Source Heat Pump System

Study and Experimental Analysis of Horizontal Ground Source Heat Pump System

of space heating and cooling is growing very fast. As a renewable energy technology, the ground source heat pump system plays an important role for the fulfill the requirement. The ground source heat pump system (GSHPs) also called as the geothermal heat pump system. Ground source heat pump system is highly efficient as compared to other conventional heat pumps. It absorbs heat from underground by pumping water through it. The heat pump then increases the temperature, and the heat is used to provide home heating. The pump needs electricity to run, but the idea is that it uses less electrical energy than the heat is produced. The heat pump performs the same role as a boiler does in a central heating system, but it uses ambient heat from the ground rather than burning fuel to generate heat. GSHP are receiving increasing interest because of their potential to reduce primary energy consumption and thus reduce emissions of greenhouse gases. This paper investigates the performance characteristics of Ground Source Heat Pump system, concentrating on thermodynamic analysis with R-22 as the refrigerant for a heating mode. The main purpose of this paper is to study the energetic potential of the deployment in Dhanbad, India of the Ground Source Heat Pump (GSHP) system for heating mode application. Therefore, a GSHP system using horizontal Ground Heat Exchanger (GHE) has been installed and experimented in BIT Sindri, Dhanbad, India. In the present study based upon the measurements made in the heating mode from the 5 th of
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Analysis on Several Heat Pump Applications in Large Public Buildings

Analysis on Several Heat Pump Applications in Large Public Buildings

ing accounts for 37% to 50% [1] of energy used. Many studies [2]-[5] on specific regions and modes about heating and cooling have been done in previous research, however, taking the origin, transport requirements and price of energy into consideration, little economic research comparing different regions and climate conditions about different heating and cooling modes has been done. Many programs can be used in district heating and cooling systems which only consider economic aspects in a simple source evaluation and ignore functional dif- ferences that may problematic in actual operation and management, causing poor performance, low energy sav- ings, poor environmental benefits, etc.
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HIGH TEMPERATURE HEAT PUMPS TECHNOLOGY FOR GEOTHERMAL DISTRICT HEATING APPLICATIONS

HIGH TEMPERATURE HEAT PUMPS TECHNOLOGY FOR GEOTHERMAL DISTRICT HEATING APPLICATIONS

solution offers a very good flexibility. Figures 1a and 1b show simplified schemas of two-stage heat pump with the heating capacity of 5'000 kW designed for a project in the region Île-de-France. In winter and intermediate season the heat pump produces hot water at 80°C and chilled water at 5°C simultaneously. As the cooling demand especially in winter is reduced, the required heat source capacity may be completed from the ground water by means of an intermediate heat exchanger. As shown in Figure 1a, the compressors are connected in series producing very high isentropic lift. The coefficient of performance (COP) for heating is 3.0 and if the complete cooling capacity of 3'350 kW may be used, the total COP for heating and cooling rises up to 5.0.
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Performance Investigation of Multiple-Tube Ground Heat Exchangers for Ground-Source Heat Pump

Performance Investigation of Multiple-Tube Ground Heat Exchangers for Ground-Source Heat Pump

The geothermal energy source is categorized based on ASHRAE [1] for using in high-temperature electric power production; > 150 ο C, intermediate and low–temperature direct-use applications; < 150 ο C, and Ground-source heat pump (GSHP) system applications; generally < 32 ο C. The GSHP system has been widely used in engineering application for space heating and cooling. The GHEs used in the GSHP system are installed in either horizontal trenches or vertical boreholes. Short-term and long-term performances are important issues of the GSHP system. Both the short-term and long-term behavior of ground loop heat exchangers is critical to the design and energy analysis of ground-source heat pump systems [2]. Short-term analysis is required for detailed building energy analysis and the design of hybrid GSHP system [3, 4]. It helps to understand the effects of short duration peak loads on the ground response [5-9] and to establish the running control strategies for alternative operation modes in short time scales of operation such as for cooling, heating, and hot water heating according to different requirements [10]. The GHEs used in the GSHP system are installed in either horizontal trenches or vertical boreholes. Temperature distributions, energy and exergy performances
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Development of an integrated building load and ground source heat pump model to assess heat pump and ground loop design and performance in a commercial office building

Development of an integrated building load and ground source heat pump model to assess heat pump and ground loop design and performance in a commercial office building

As a result of these challenges, “Modeling approaches to infiltration are typically very simple” (U.S. Department of Energy, 2010, p. 29). In many commercial applications, it is assumed that building envelopes are airtight, but Persily and Grot found that when results are normalized by envelope area, envelope airtightness for American commercial buildings display similar levels of airflow as American houses (ASHRAE 2009 Fundamentals HandBook, 2009, p. 16.25). Another approach applies a fan pressurization test to measure flow rate through a building’s envelope at a certain supply pressure, and subsequently normalizes the flow rate by the building’s surface area. Using this method, Persily and Grot found air leakage rates, “Ranging from 1080 to 5220cm 3 /(s ·m 2 ) at 75Pa” (ASHRAE 2009 Fundamentals HandBook, 2009, p. 16.25). Tamura and Shaw found that air leakage values at 75Pa for tight, average and leaky walls were “500, 1500, and 3000cm 3 /(s ·m 2 )” respectively (ASHRAE 2009 Fundamentals HandBook, 2009, p. 16.25). ASHRAE Standard 90.1-2004 proposed an ideal maximum building leakage of 2000cm 3 /(s ·m 2 ) for above-grade envelope area (exterior walls and roof) (U.S. Department of Energy, 2010, p. 29).
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Experimental Study and Modeling of Ground-Source Heat Pumps with Combi-Storage in Buildings

Experimental Study and Modeling of Ground-Source Heat Pumps with Combi-Storage in Buildings

Abstract: There is a continuous growth of heat pump installations in residential buildings in Germany. The heat pumps are not only used for space heating and domestic hot water consumption but also to offer flexibility to the grid. The high coefficient of performance and the low cost of heat storages made the heat pumps one of the optimal candidates for the power to heat applications. Thus, several questions are raised about the optimal integration and control of the heat pump system with buffer storages to maximize its operation efficiency and minimize the operation costs. In this paper, an experimental investigation is performed to study the performance of a ground source heat pump (GSHP) with a combi-storage under several configurations and control factors. The experiments were performed on an innovative modular testbed that is capable of emulating a ground source to provide the heat pump with different temperature levels at different times of the day. Moreover, it can emulate the different building loads such as the space heating load and the domestic hot water consumption in real-time. The data gathered from the testbed and different experimental studies were used to develop a simulation model based on Modelica that can accurately simulate the dynamics of a GSHP in a building. The model was validated based on different metrics. Energetically, the difference between the developed model and the measured values was only 3% and 4% for the heat generation and electricity consumption, respectively.
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Ground Source Heat & Shallow Geothermal Energy

Ground Source Heat & Shallow Geothermal Energy

Subsoil type map Identifies different subsoil types that occur between the base of the soil zone and above the top of the bedrock. Different subsoil types have different moisture contents and thermal properties. Tills (shown in dark blue and purple) can be silt- or clay- rich, with clays particularly favouring moisture retention. Peats (shown in brown) have a very high moisture content. Sands/gravels (shown in green), unless fully saturated with groundwater (i.e. below the water table), are generally poor at retaining moisture and, therefore, are poor at conducting heat through the ground. Alluvium (river sediments, shown in orange) are usually saturated, but limited in extent.
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Parametric Study of Vertical Ground Loop Heat Exchangers for Ground Source Heat Pump Systems

Parametric Study of Vertical Ground Loop Heat Exchangers for Ground Source Heat Pump Systems

The average convective heat transfer coefficient, h, for the fluid along the full length of the U-tube pipe was computed as a part of simulation and was found to be 1779 W/m 2 K. This value is consistent with typical heat transfer coefficient values for turbulent flows in similar conditions [e.g. see Schwencke 2013 and Young 2004]. The magnitudes of individual thermal resistances were computed to quantify the contribution of each thermal resistance to the heat flow and to determine which one is the controlling thermal resistance. As mentioned earlier in Chapter 1, there are two fluid nodes in the given case and also the conductive thermal resistance in the grout is 2D, which makes it difficult to accurately quantify each thermal resistance. As seen earlier in the results, the difference in fluid temperatures between the two pipes is very small as compared to that in the grout, hence, to simplify this analysis, a single fluid node is assumed. Based on computed heat transfer coefficient and other physical and thermal properties of the model the individual thermal resistance of each component was calculated using the equations outlined in section 1.2.4. The values of these thermal resistances are presented in Table 3-4.
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Simplified modelling of air source heat pumps producing detailed results

Simplified modelling of air source heat pumps producing detailed results

The SAP methodology may benefit by the creation of a tool to simply estimate the potential impact of innovative technologies to energy estimation and regulation. This tool could also address the discrepancies raised with the current SAP methodology. A novel advanced dynamic calculation method (IDEAS – Inverse Dynamics based Energy Analysis and Simulation) of assessing the controllability of a building and its servicing systems has been developed. The IDEAS method produces results that are comparable to SAP. The purpose of the IDEAS tool is to suggest where advanced controllability of dwellings and a dynamic framework could supplement SAP. The IDEAS calculation method is based upon current SAP parameters to produce a simple to use method which is familiar to current users of SAP: most importantly IDEAS has been calibrated with over a large range of test cases. IDEAS allows for an extension of SAP in many areas such as: the use of various climate files with values that change on a minutely and not monthly or yearly basis, the flexibility to amend the heating setpoint which is tracked (for example, comparisons can be made between tracking a constant setpoint of 21 degrees vs. the Standard varying SAP setpoint) and the additional of advanced controllability algorithms to be applied to a SAP environment. IDEAS has been described in depth (8, 9).
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Damage event analysis of vertical ground source heat pump systems in Germany

Damage event analysis of vertical ground source heat pump systems in Germany

sidence of up to 10 cm was measured up to a distance of 200 m from the drilling site. Cracks started to appear in adjacent buildings. Twenty neighbouring houses were dam- aged and four of them finally had to be demolished (AD-HOC-AG Geologie 2011). With a final depth of 70 m, drillings had reached the transitional zone between the Emscher formation and the karstified Plänerkalk group (Fig. 4). The Emscher formation and par- ticularly the Plänerkalk group are characterised by water-conducting faults that are interconnected with the karst system of the Plänerkalk group (AD-HOC-AG Geologie 2011). Low volumes of cuttings indicated a loss of drilling fluid during the drilling pro- cess already. The cuttings were flushed into the karst system by the drilling fluid. The loss of drilling fluid went unnoticed at the surface: groundwater flow from the quater- nary aquifer into the borehole compensated the loss of drilling fluid. Groundwater flow was facilitated by the absence of an annulus casing. When the drilling team pulled out the pipes in the evening, groundwater flow was reinforced. With increasing flow veloci- ties, large amounts of sediment were eroded and transported into the karst formation. A sinkhole formed around the uncased annulus. At a certain point, the material loss was balanced by a lateral mass transfer from the quaternary aquifer. This subrosion process led to subsidence in the surrounding area. The borehole was grouted with 750  m 3 of
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Non-ducted air conditioners and heat pumps Testing and rating for performance

Non-ducted air conditioners and heat pumps Testing and rating for performance

Note 1 to entry: It can be either single-package or split-system and comprises a primary source of refrigeration for cooling and dehumidification. It can also include means for heating other than a heat pump, as well as means for circulating, cleaning, humidifying, ventilating or exhausting air. Such equipment can be provided in more than one assembly, the separated assemblies (split-systems) of which are intended to be used together.

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Performance evaluation of reversible heat pumps when using refrigerant mixtures

Performance evaluation of reversible heat pumps when using refrigerant mixtures

The presence o f more than one component in mixture refrigerants changes the superheat required to initiate and sustain nucléation [Shock, 1977]. This change in the effective superheat is the main and the most complex contribution to the HTC degradation o f mixtures [Collier and Thome, 1996]. Bubble growth during nucléation is limited by the fact that the liquid close to the bubble surface becomes depleted in the more volatile component. As shown in figure 2.6, in the case of a binary mixture, the minimum heat flux increases with the presence o f an additional component. This indicates that relatively a higher amount of heat transfer and a larger wall superheat are required to initiate the boiling process; implying a delay in the onset o f nucleate boiling [Wang and Chato, 1995b]. These cause considerable reduction in nucleate boiling heat transfer.
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Performance Assessment of a Variable Capacity Air Source Heat Pump and a Horizontal Loop Coupled Ground Source Heat Pump System

Performance Assessment of a Variable Capacity Air Source Heat Pump and a Horizontal Loop Coupled Ground Source Heat Pump System

Energy savings from the use of these more efficient heat pump systems translated into significant reductions in greenhouse gas emissions relative to conventional alternatives. Annual electricity savings relative to a conventional electric furnace and air conditioner were converted to the equivalent carbon dioxide based on electricity generation sources in Ontario to arrive at emission reductions of 2,330 and 2,449 kg eCO 2 for the ASHP and GSHP, respectively. If instead, the heat pump displaced natural gas during the heating season, the annual emissions reductions would rise to 3329 and 3549 kg eCO 2 . By comparison, average per capita emissions from private vehicles in Canada was 2149 kg eCO 2 in 2007 (Statistics Canada, 2010). Thus, the emissions savings from heat pumps are greater than the savings achieved by a family that chooses to replace all annual car travel with zero emission alternatives such as walking or biking. As the electrical grid in Ontario continues to decarbonize, future emissions reductions associated with heat pump systems will also continue to rise.
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“OPTIMIZATION OF GROUND SOURCE HEAT PUMP:A REVIEW”

“OPTIMIZATION OF GROUND SOURCE HEAT PUMP:A REVIEW”

Jimin Kim et. al. [2015] [11] In order to solve environmental problems such as global warming and resource depletion in the construction industry, interest in new renewable energy (NRE) systems has increased. The ground source heat pump (GSHP) system is the most efficient system among NRE systems. However, since the initial investment cost of the GSHP is quite expensive, a feasibility study needs to be conducted from the life-cycle perspective. Meanwhile, the efficiency of GSHP depends most significantly on the entering water temperature (EWT) of the ground heat exchanger (GHE). Therefore, this study aims to assess the environmental and economic effects of the use of GHE for selecting the optimal GHE. This study was conducted in three steps: (i) establishing the basic information and selecting key factors affecting GHE performances; (ii) making possible alternatives of the GHE installation by considering EWT; and (iii) using life-cycle assessment and life-cycle cost, as well as comprehensive evaluation of the environmental and economic effects on the GHE. These techniques allow for easy and accurate determination of the optimal design of the GHE from the environmental and economic effects in the early design phase. In future research, a multi-objective decision support model for the GSHP will be developed.
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'' SEISMIC ANALYSIS OF BUILDINGS RESTING ON SLOPING GROUND ''

'' SEISMIC ANALYSIS OF BUILDINGS RESTING ON SLOPING GROUND ''

In this study various numbers of structures are modelled and analyzed which are same in plan but vary in total height of building i.e. number of story variations. All columns, beams and structural slabs were included in the model of each building. All models are subjected to dynamic analysis with the help of ETABS 2013. The dimension of all the beams and columns are design according to IS 456-2000 .The building is designed to resist dead load, live load & seismic load and all the result based on IS1893:2000 13 combination are taken for the analysis and design all 24 model.
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Time History analysis  of the buildings on sloping ground

Time History analysis of the buildings on sloping ground

In normal design practice the designers generally ignore the effect of sloping ground on the structural behavior of the building. It is very important to consider earthquake effect and design earthquake resistant buildings from the safety point of view. Earthquake is the most disastrous due to its unpredictability and huge power of devastation. Earthquakes themselves do not kill people, rather the colossal loss of human lives and properties occur due to the destruction of structures. Earthquakes causes serious damage to buildings, such as failure of members in the building and if the intensity of earthquake is high, it leads to collapse of the structure. Hill buildings constructed in masonry with mud mortar or cement mortar without conforming to seismic codal provisions have proved unsafe and resulted in loss of life and property when subjected to earthquake ground motions. In recent years population has been increased drastically and due to which cities and towns started spreading out. The economic growth and rapid urbanization in hilly region has accelerated the real estate development. Due to this, population density in the hilly region has increased enormously. Therefore,
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