Energy Analysis and Optimization of a Water-Loop Heat Pump System

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Shui Yuan ◽  
Michel Grabon
Keyword(s):  
Water Temperature ◽  
Heat Pump ◽  
Energy Savings ◽  
Water Source ◽  
Energy Performance ◽  
Heat Pumps ◽  
Pump System ◽  
Heat Pump System ◽  
Heating And Cooling ◽  
The Impact

A water-loop heat pump system consists of a set of water-source heat pumps that are connected with a closed-loop water network, which allows heat to be injected into or extracted out of the loop water. Such a configuration is able to meet simultaneous heating and cooling demands with a heat recovery capability. This paper analyzes the impact of loop water temperature on energy performance of individual heat pumps and the whole system, demonstrates that there exists a unique loop water temperature that minimizes overall power consumption of the configuration under discussion, and proposes a strategy to find the optimal temperature, which can be implemented in a real-time application. Simulations have been conducted to verify that a significant energy savings can be achieved over conventional practice.

Analysis of Water Heat Pollution of Thermal Discharge in Surface Water Source Heat Pump System

2013 ◽  
Vol 368-370 ◽  
pp. 364-368
Author(s):  
Min Wang ◽  
Yue Jin Yu
Keyword(s):  
Surface Water ◽  
Water Temperature ◽  
Heat Pump ◽  
Preventive Measures ◽  
Water Source ◽  
Heat Pumps ◽  
Thermal Discharge ◽  
Pump System ◽  
Heat Pump System ◽  
Local Water

To comprehensively evaluate surface water source heat pump system, the problem of water heat pollution of thermal discharge in surface water source heat pump system should be seriously considered. This study summarizes the causes and hazards of water heat pollution of surface water source heat pump, explores the characteristics of water heat pollution of lake-source heat pump system, river-source heat pump system and sea-source heat pump system respectively, and proposes several preventive measures for solving the problem. Concludes that surface water heat pumps discharges can change local water temperature, and various types of water bodies have different degree of heat pollution.

Photovoltaic thermal collector assisted heat pumps using environment-friendly working fluids

2020 ◽  
pp. 095440892094736
Author(s):  
AA Ammar ◽  
K Sopian ◽  
M Mohanraj
Keyword(s):  
Heat Pump ◽  
Energy Performance ◽  
Heat Pumps ◽  
Payback Period ◽  
Photovoltaic System ◽  
Coefficient Of Performance ◽  
Photovoltaic Module ◽  
Pump System ◽  
Heat Pump System ◽  
Thermal Evaporator

In this research, a photovoltaic-thermal collector assisted heat pump has been developed and tested its performance under the tropical climatic conditions of Malaysia. The refrigerants such as, R134a and R1234yf were selected based on its thermodynamic and thermo-physical properties. The temperature of the photovoltaic module was theoretically predicted under the influence of tube diameter, tube spacing and refrigerant mass flow rate. Further, the energy performance of the photovoltaic-thermal evaporator and the heat pump system are investigated experimentally. Finally, the economical feasibility of the photovoltaic-thermal collector evaporator was assessed for the period of 20 years. The results showed that, the tube spacing and diameter of the copper tubes used in the photovoltaic-thermal evaporator/collector using R134a and R1234yf were optimized to 80 mm and 12.7 mm, respectively. It was observed that, during the clear sunny day, the average photovoltaic module temperature was reduced to 30.9 °C under the influence of panel cooling using refrigerant. The output of the panel was enhanced by 21%–44% with increase in solar radiation from 400 W/m2 to 1000 W/m2. The coefficient of performance of the heat pump was varied from 4.8 to 6.84 with an average coefficient of performance of 5.8 during clear sunny days. The life cycle economic analysis indicated that, the photovoltaic-thermal collector evaporator assisted heat pump has a payback period of 3 years, whereas the reference photovoltaic system has a payback period of 8 years.

scholarly journals Design and Analysis of a Distributed Water Heat Pump System for Near- and Net-Zero Energy Commercial Buildings

2021 ◽  
Author(s):  
Maudud Hassan Quazi
Keyword(s):  
Natural Gas ◽  
Heat Pump ◽  
Cooling Tower ◽  
Heat Pumps ◽  
Base Case ◽  
Hvac System ◽  
Pump System ◽  
Heat Pump System ◽  
Heating And Cooling ◽  
Net Zero

This objective of this project is to determine the energy and environmental potential of distributed common loop water source heat pump system in a near or net-zero commercial office building, which has simultaneous heating and cooling load in winter and shoulder seasons. It is expected that the perimeter zones will have heating demand during those months, while the core zones will have consistent cooling demand throughout the year. The motive is to reclaim the rejected heat from the cooling operation and transfer it to the zones requiring heating. The building under study is a 60,000 ft2 three storey commercial office building, which has private offices along the perimeter, and open work area in the core. In the first part of the analysis, the base building has been modelled and simulated to the minimum requirements of ASHRAE 90.1-Energy Standard for Buildings except Low-Rise Residential Buildings using simulation software eQuest 3.65. The Heating Ventilation and Airconditioning (HVAC) system used is four-pipe fan coil system serving individual zones. The fan coil units use a centralized natural gas boiler and a variable capacity centrifugal chiller as external source of heating and cooling respectively. The base case consumes a total of 524.54 x 1000 kWh of electricity and 1,056 million Btu of natural gas annually. The second part is the modelling and simulation of a proposed case, which uses the same building envelope, occupancy, lighting and equipment as the base case. The HVAC system used is a distributed common loop heat pump system connected to a cooling tower for heat rejection, and a condensing boiler for heat addition. During the occupied hours, when simultaneous cooling and heating loads exist in the building, the cooling zone heat pumps rejects exhaust heat into the common loop, and the heat is subsequently used by the heat pumps operating in heating mode. Using this method, the heat pump system reduces its dependence on the cooling tower and the boiler, which only operate to maintain the loop temperature in an acceptable range. There is 9,510 kWh (1.81%) increase in electricity consumption by proposed case comparing to the base building. Natural gas consumption has been reduced by 353.65 million Btu (33.48%). Annual utility bill has increased by $1,483.00 which is 1.88% higher than the base case. 15.7 tonnes of greenhouse gas can be reduced if the proposed case is adopted.

scholarly journals Heat Pump Heating System Development of Educational Building based on Energy, Economical and Environmental Impacts

2019 ◽  
Vol 63 (3) ◽  
pp. 207-213
Author(s):  
Miklós Kassai
Keyword(s):  
Heat Pump ◽  
Energy Savings ◽  
System Development ◽  
Heating System ◽  
Heat Pumps ◽  
The European Union ◽  
Pump System ◽  
Environmental Friendliness ◽  
Heat Pump System ◽  
Payback Time

In this research the technical designing of energy efficient heating system with vertical-borehole heat pumps for institutional buildings was performed. The local government would like to change the old gas boiler-based heat producing system to up-to-date, environmental friendly equipment with the financial support of the European Union. The payback time was calculated and environmental calculations were achieved with carbon dioxide saving by various conditions that were also achieved during the research project. The results show that the heat pump system also provides a significant reduction of environmental load, in addition to significant energy savings. The amount of calculated savings justifies the environmental friendliness of heat pump systems.

scholarly journals Design and Analysis of a Distributed Water Heat Pump System for Near- and Net-Zero Energy Commercial Buildings

2021 ◽  
Author(s):  
Maudud Hassan Quazi
Keyword(s):  
Natural Gas ◽  
Heat Pump ◽  
Cooling Tower ◽  
Heat Pumps ◽  
Base Case ◽  
Hvac System ◽  
Pump System ◽  
Heat Pump System ◽  
Heating And Cooling ◽  
Net Zero

This objective of this project is to determine the energy and environmental potential of distributed common loop water source heat pump system in a near or net-zero commercial office building, which has simultaneous heating and cooling load in winter and shoulder seasons. It is expected that the perimeter zones will have heating demand during those months, while the core zones will have consistent cooling demand throughout the year. The motive is to reclaim the rejected heat from the cooling operation and transfer it to the zones requiring heating. The building under study is a 60,000 ft2 three storey commercial office building, which has private offices along the perimeter, and open work area in the core. In the first part of the analysis, the base building has been modelled and simulated to the minimum requirements of ASHRAE 90.1-Energy Standard for Buildings except Low-Rise Residential Buildings using simulation software eQuest 3.65. The Heating Ventilation and Airconditioning (HVAC) system used is four-pipe fan coil system serving individual zones. The fan coil units use a centralized natural gas boiler and a variable capacity centrifugal chiller as external source of heating and cooling respectively. The base case consumes a total of 524.54 x 1000 kWh of electricity and 1,056 million Btu of natural gas annually. The second part is the modelling and simulation of a proposed case, which uses the same building envelope, occupancy, lighting and equipment as the base case. The HVAC system used is a distributed common loop heat pump system connected to a cooling tower for heat rejection, and a condensing boiler for heat addition. During the occupied hours, when simultaneous cooling and heating loads exist in the building, the cooling zone heat pumps rejects exhaust heat into the common loop, and the heat is subsequently used by the heat pumps operating in heating mode. Using this method, the heat pump system reduces its dependence on the cooling tower and the boiler, which only operate to maintain the loop temperature in an acceptable range. There is 9,510 kWh (1.81%) increase in electricity consumption by proposed case comparing to the base building. Natural gas consumption has been reduced by 353.65 million Btu (33.48%). Annual utility bill has increased by $1,483.00 which is 1.88% higher than the base case. 15.7 tonnes of greenhouse gas can be reduced if the proposed case is adopted.

scholarly journals Measured performance of exhaust air heat pumps in Finnish apartment buildings

2021 ◽  
Vol 246 ◽  
pp. 06001
Author(s):  
Petri Pylsy ◽  
Jarek Kurnitski
Keyword(s):  
Heat Pump ◽  
Ventilation System ◽  
Measurement Data ◽  
District Heating ◽  
Energy Performance ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Apartment Buildings

The energy efficiency of existing apartment buildings is playing an important role in energy and climate targets. In Finland, mechanical exhaust ventilation system is commonly used in older apartment buildings. Hence, there could be an energy saving potential by an exhaust air heat pump system (EAHP). In this work two cases have been studied. Buildings were built in 1960’s and 1970’s and in renovation equipped with hybrid heating system: district heating and exhaust air heat pump system. Two years measurement data, 2018 and 2019, was collected to evaluate the performance of exhaust air heat pump systems. According to measurement data the monthly coefficient of performance (COP) was calculated as well as seasonal coefficient of performance (SCOP) was defined. The monthly COP values varied from 3,1 to 4,6 and SCOP values were about 3,7. Heating energy cost savings were 23-31 %. Energy performance class before and after EAHP installation was calculated. If at least 50 % of heating energy consumption was covered by EAHP then also energy performance class was improved.

scholarly journals Life cycle cost analysis of different residential heat pump systems

2020 ◽  
Vol 207 ◽  
pp. 01014
Author(s):  
Nadezhda Doseva ◽  
Daniela Chakyrova
Keyword(s):  
Energy Efficiency ◽  
Life Cycle ◽  
Heat Pump ◽  
Life Cycle Cost ◽  
Residential Buildings ◽  
Energy Performance ◽  
Coefficient Of Performance ◽  
Pump System ◽  
Heat Pump System ◽  
Heating And Cooling

Nowadays, the application of air-source heat pumps for heating and cooling in residential buildings has been increased significantly. The main occasion for this is the accessibility of a heat source for these devices - the external air. Nevertheless, the increase of the energy efficiency of the air source heat pump systems is a difficult design problem because their capacity and performance are a function of the dynamically changing parameters of the outdoor air. Because of that, the main aim of this study is to develop an approach for choosing a structural scheme of an air-to-water heat pump system under specific climatic conditions. The considered systems are monovalent, bivalent-parallel and bivalent-alternative heat pump systems. In the current paper is conducted a dynamic energy modeling of heating and cooling demand of a typical residential building situated in Varna, Bulgaria and applying the bin temperature data. It is assessed the effect of the heat pump capacity over the annual and seasonal energy performance of the heat pump systems. It is established the effect of the bivalent temperature, cut-off temperature and on-off cycles duration on rates of the criteria for techno-economic assessment. The seasonal coefficient of performance (SCOP), seasonal energy efficiency rate (SEER) and life cycle costs (LCC) of the analyzed heat pump systems are adopted as assessment parameters.

Analysis of the Water Intake Technology of Open-Lakes Water Source Heat Pump System in Chongqing

2011 ◽  
Vol 250-253 ◽  
pp. 3168-3172
Author(s):  
Gong Duan Fan ◽  
Zhi Zhang ◽  
Jing Luo ◽  
Xin Wan ◽  
Chao Liu
Keyword(s):  
Water Quality ◽  
Water Temperature ◽  
Heat Pump ◽  
Water Intake ◽  
Lower Layer ◽  
Water Source ◽  
Pump System ◽  
Heat Pump System ◽  
Distribution Features ◽  
Lakes And Reservoirs

To research the suitable water intake technology of open-lakes Water Source Heat Pump system (WSHPs) in Chongqing, water temperature, water quality and other water features of lake and reservoir are analyzed. Results show that the temperature of water source in Chongqing’s lakes and reservoirs excelled the air temperature, and the water quality basically meets the requirements of open-lakes WSHPs. Thus the water source in Chongqing’s lakes and reservoirs is a hot and cold source of good quality. For depth of water is greater than 6m, there is an obvious vertical stratification of water temperature in summer, which is not obvious in winter. pH value, turbidity and algal density also have obvious characteristics in vertical distribution, while hardness and salinity have little characteristics. According to the spatial and temporal distribution features of water temperature and water quality, water intake head should be installed in the middle and lower layer of the lake. Less investment and water head loss, lower operation and maintenance costs, and higher reliability should be considered when we choose the way of water intake for WSHPs in Chongqing. Water intake ways such as pump truck water intake, pontoon intake, gravity pipe intake, integrated device are alternative. Comparison between technical and economic should be made first.

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