scholarly journals Influence of the quantity profile of the domestic hot water demand and the energy demand for the heating in a single-family house on the SCOP of the air-to-water heat pump

2018 ◽  
Vol 44 ◽  
pp. 00162 ◽  
Author(s):  
Kamil Skoneczny

In the article it was discussed how the energy efficiency of the air-to-water heat pump can change depending on the different ways of the building usage. The author shows that the following factors influence this efficiency: the DHW demand and the demand of the energy for the heating of the building. The article shows that it is very important to take into account the cooperation of both systems, the DHW and the heating. Two models of the SCOP calculations were discussed: in monthly and hourly steps of the calculation. For each model the following assumptions were considered: the different profiles of the domestic hot water demand and the different profiles of the demand for the heating of building.

2018 ◽  
Vol 44 ◽  
pp. 00158
Author(s):  
Ilona Rzeźnik

The results of experimental investigation of determining the time of temperature drop in domestic hot water circuit were presented in this paper on the example of single-family house. The test were carried out on vertical sections of installations made of PE-X/Al/PE pipes (cross-linked polyethylene and aluminum) with and without insulation. The temperature drop process was investigated in temperature range typical for domestic hot water installation from 55ºC to 40ºC. On the basis of the obtained results with appropriate adjustment of the working time of circulation pump, energy savings of 90% were achieved.


2021 ◽  
Vol 2095 (1) ◽  
pp. 012077
Author(s):  
Xiaoming Zhang ◽  
Qiang Wang ◽  
Qiujin Sun ◽  
Mingyu Shao

Abstract There have been few practical applications of solar coupled groundwater source heat pump (GWHP) systems in large public buildings, and data on this technology are scarce. A solar coupled GWHP system was investigated in this study. The system uses an underground water source heat pump system for heating in winter, cooling in summer, and providing part of the domestic hot water, and it also uses a solar energy system to prepare domestic hot water. These two types of energy are complementary. The system was tested throughout the cooling season. This experiment ran from May 10, 2021, to September 10, 2021. The results show that the system can guarantee the indoor design temperature and the supply of domestic hot water. The solar water heating system operated for 1233 min in the summer; hot water (2334 m3) was prepared. During the summer, the average energy efficiency ratio of the GWHP unit was approximately 4.88. The energy efficiency ratio of the entire system was approximately 3.34. Such projects can play a key role in demonstrating this type of system.


Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5476
Author(s):  
Sławomir Zator ◽  
Waldemar Skomudek

This article presents a case study of a single-family house, whose current energy source is electricity only. Nine years ago, the heat source for the heating system and domestic hot water was an oil boiler, which was changed to an air–water heat pump. Four years ago, when Poland formed the basis of the prosumer market, the first photovoltaic system was established. It was expanded in the following years. In this work are presented the impact of using a heat accumulator on the coefficient of performance of the heat pump, the self-consumption of energy from the photovoltaic system, and the cost of purchasing energy. Comparative calculations were made, with the demand-side management (DSM) active on work days, and on free days (weekends and public holidays) it was not. Attention was paid to the self-consumption factor depending on the algorithms used in an energy meter. The prosumer market in Poland was also described. The calculations described the house as having an annual energy self-consumption from photovoltaic about 6% higher than average values obtained in buildings with heat pumps. Simultaneously, due to energy storage in heat and the load shifting in the multi-zone tariff, the cost of purchasing energy was 47% lower than in a single-zone tariff (without heat storage and load shifting).


Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8238
Author(s):  
Paolo Artuso ◽  
Giacomo Tosato ◽  
Antonio Rossetti ◽  
Sergio Marinetti ◽  
Armin Hafner ◽  
...  

This paper presents a reversible heat pump based on CO2 as the refrigerant, able to provide heating, cooling, and domestic hot water to high energy demand buildings. The unit was developed and tested under the EU H2020 project MultiPACK, which has the main goal of assuring the market about the feasibility, reliability, and energy efficiency of CO2 integrated systems for heating and cooling and promoting a fast transition to low environmental impact solutions. Within the project, the confidence raising was performed by installation and monitoring of fully integrated state-of-the art CO2 systems in the Southern European Climate. With the aim of predicting the unit behaviour under variable load and boundary conditions, a dynamic model of the entire unit was developed with commercial software, considering actual components and the implemented control system and it was validated with experimental data, collected at the factory’s lab before commissioning. The validation against experimental data collected during operation as a heat pump demonstrated a maximum percentage difference between the experimental and predicted value of gas–cooler heat flow rate equal to +5.0%. A preliminary comparison with the experimental data in chiller configuration is reported, however further development was required to achieve a satisfactory validation. Lastly, the numerical model was utilized to simulate a typical operation in heat pump configuration with the system coupled with a hot water tank storage for the production of domestic hot water and space heating; the model predicts higher COP when operating in domestic hot water operation due to the lower water inlet temperature.


Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6509
Author(s):  
Agnieszka Malec ◽  
Tomasz Cholewa ◽  
Alicja Siuta-Olcha

Domestic hot water preparation is one of the main sources of energy consumption in households. One of the most important elements of domestic hot water (DHW) preparation installation is the storage tank. Its design can significantly affect the efficiency of the system and energy consumption for hot water preparation. This paper presents the results of an experimental study to examine seven different designs of the cold water inlet to the storage tank and the use of two types of obstacles inside this tank placed at three different heights. The number of stratification and the energy efficiency of the system for each variant were examined. Additionally, tests were carried out for different profiles of hot water consumption in order to examine the temperature changes in the DHW tank. A system with an inlet, as an elbow facing down with a single plate, turned out to be the most advantageous variant (3–8% increase in energy efficiency compared to the basic inlet variant). An analogous analysis of the use of obstacles inside the tank showed that the most optimal solution is to place the partition, which allows the water flow on the sides of the tank, in its lower parts (energy efficiency higher by up to 15% compared to the variant without a partition). These solutions showed the highest energy efficiency for DHW production and the lowest energy demand for hot water heating in the tank among all analyzed variants.


Sign in / Sign up

Export Citation Format

Share Document