Small ammonia heat pumps for space and hot tap water heating

Zajacs, Aleksandrs; Lalovs, Arturs; Borodiņecs, Anatolijs; Bogdanovics, Raimonds

doi:10.1016/j.egypro.2017.07.307

Cited by 9 publications

(9 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The measured heating COP was 3.8 to 4.8 for evaporating temperatures ranging from −13 °C to 2 °C and a condensing temperature of 48 °C. Zajacs et al (2017) designed an 8.4 kW NH 3 GSHP to provide space heating and DHW. They chose the main components and materials to avoid corrosion, and optimized the tank volume to minimize heating demand during the peak hours with high electricity price.…”

Section: Progress In Gshps Using Nh3mentioning

confidence: 99%

Progress in ground-source heat pumps using natural refrigerants

Skye

2018

International Journal of Refrigeration

View full text Add to dashboard Cite

Natural refrigerants are attractive candidates for replacing the high Global-Warming- Potential fluorinated refrigerants used in ground-source heat pumps (GSHPs). This paper presents a comprehensive survey on GSHPs using CO2, NH3, water, and hydrocarbons. We compared the refrigerants’ thermodynamic properties, analyzed their performance in brine-to-air and brine-to-water GSHPs, and discussed recent progress in their use in GSHPs. Studies of CO2 were the most common due to its favorable properties, covering advanced cycles, direct-expansion, secondary fluid, and hybrid GSHPs. Though with toxicity concerns, NH3 was the second most studied, including vapor-compression GSHPs for heating, absorption-type GSHPs to eliminate ground imbalance, and hybrid compression-absorption GSHPs to widen the operating temperature range. A few studies evaluated water as a refrigerant for absorption-type GSHPs, including applications for solar cooling, ground imbalance, and district heating. Propane was the only hydrocarbon considered for GSHPs, including analyses on refrigerant charge, performance analysis, and propane as a secondary fluid.

show abstract

Section: Progress In Gshps Using Nh3mentioning

confidence: 99%

Progress in ground-source heat pumps using natural refrigerants

Skye

2018

International Journal of Refrigeration

View full text Add to dashboard Cite

show abstract

“…As residents' living standards are continuously improved, the demand for building heating energy consumption will gradually increase, thus making full use of renewable energy becomes a momentous method to meet the increasing demand of building heating energy consumption [1][2][3]. Solar water heating systems and air source heat pump (ASHP) systems are widely used in people's lives because of their energy-saving properties and low cost of use [4,5].…”

Section: Introductionmentioning

confidence: 99%

Simulation Research on the Heating Performance of the Combined System of Solar Energy and Heat-Source Tower Heat Pump in a Hot Summer and Cold Winter Area

Shen

Yongga

2021

Energies

View full text Add to dashboard Cite

Three connection methods for the combined heating systems of a closed-type heat-source tower heat pump (CHTHP) and solar collector (SC) were proposed in this paper: the heat-source tower (HST) and solar collector were connected in series (HST+SC), and the solar collector and heat pump (HP) condenser were connected in series (SC+HP) and in parallel (SC//HP). The calculation module of the closed heat-source tower was built using programming software based on C++ language, and three corresponding calculation models of the combined heating systems were established in the TRNSYS. Under the climatic conditions of the cold season in Changsha, the combined heating performance of the three systems was simulated and analyzed. The results indicate that the simulation results of the established models are in good agreement with the test results, and the simulation results can be used for the research of the system’s combined heating performance. When the outdoor air temperature and solar radiation intensity are low, the HST+SC system has the best heating performance; however, when the solar radiation intensity and ambient temperature are high, the heating performance of the SC//HP system is the best. When the solar radiation intensity and outdoor air temperature are between the previous two working conditions, the SC+HP system is the best performer for heating among the three systems. On the basis of the collector area and heat pump power designed in this study, the best operating condition interval diagrams of the three combined heating systems are established.

show abstract

“…To address the degradation performance problem caused by an imbalance in the heating and cooling loads, a number of researchers have proposed hybrid GHE systems and different operation strategies [3]. For example, hybrid GHE, solar energy systems, and heat pump have been suggested by a number of researchers [4][5][6][7][8], to cope with performance deterioration. Dai et al [4] carried out an experimental study on a solar assisted ground source heat pump system.…”

Section: Introductionmentioning

confidence: 99%

“…While the theoretical COPs were found to be 3.67, 3.64, and 3.52, which are quite different from the theoretical values. In addition, research on small ammonia heat pumps for space and hot tap water heater with a capacity of 8.4 kW to provide space heating and hot water has been done by Aleksandrs Zajacs et al [8]. In this study, equation calculations have been carried out using the engineering equation solver (EES) to estimate the heat pump performance.…”

Section: Introductionmentioning

confidence: 99%

Mathematical Modelling and Operational Analysis of Combined Vertical–Horizontal Heat Exchanger for Shallow Geothermal Energy Application in Cooling Mode

Sofyan

Kotousov

et al. 2020

Energies

View full text Add to dashboard Cite

Geothermal heat exchangers (GHEs) represent a buried pipe system, which can be utilised to harness renewable thermal energy stored in the ground to improve the efficiency of heating and cooling systems. Two basic arrangements of GHEs have been widely used: vertical and horizontal. Vertical GHEs generally have a better performance in comparison with the horizontal arrangement, and these systems are particularly suitable for confined spaces. Nevertheless, the main technical challenge associated with GHEs, for either the vertical or the horizontal arrangement, is the performance deterioration associated with an increase in the operation times during summer or winter seasons. In this paper, a combined horizontal-vertical GHE arrangement is proposed to address the current challenges. The combined GHE arrangement can be operated in five different modes, corresponding to different thermal loading conditions. These five operation modes of the combined GHE are analysed based on the transient finite difference models previously developed for the horizontal and vertical arrangements. The simulation results reveal that for the single operation mode (horizontal or vertical only), the vertical GHE performs better than the horizontal GHE due to relatively stable ground temperature deep down. While, for the combined operation mode, the series operations (horizontal to vertical or vertical to horizontal) of the GHE are superior to the split mode. It is found that the effect of the fluid mass flow rate ratio is trivial on the heat dissipation of the split mode GHE. The highest heat transfer rate in the split flow operational mode is rendered by the ratio of the mass flow rate of 40% horizontal and 60% vertical. In addition, the climate condition has more effect on GHE’s performance and the increase of the fluid flow rate it can enhance the amount of energy released by the GHE.

show abstract

Small ammonia heat pumps for space and hot tap water heating

Cited by 9 publications

References 4 publications

Progress in ground-source heat pumps using natural refrigerants

Progress in ground-source heat pumps using natural refrigerants

Simulation Research on the Heating Performance of the Combined System of Solar Energy and Heat-Source Tower Heat Pump in a Hot Summer and Cold Winter Area

Mathematical Modelling and Operational Analysis of Combined Vertical–Horizontal Heat Exchanger for Shallow Geothermal Energy Application in Cooling Mode

Contact Info

Product

Resources

About