Theoretical and experimental analysis of a CO2 heat pump for domestic hot water

Minetto, Silvia

doi:10.1016/j.ijrefrig.2010.12.018

Cited by 107 publications

(27 citation statements)

References 23 publications

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“…Nekså proposed that CO 2 is highly suitable for application of building heating . It has been used in a variety of applications like fire extinguisher, lasers, refrigeration, supercritical drying, domestic hot water, solar water heating, mobile air conditioning (MAC) and heating for vehicles, CO 2 heat pump with Phase Change Materials, and geothermal heat transfer fluid, and so on. Gullo et al investigated the efficiency of R404A and R744 systems.…”

Section: History Of Refrigerantsmentioning

confidence: 99%

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

2019

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Summary Refrigerants bearing high global warming potential (GWP) and ozone depletion potential (ODP) were outlawed or facing time‐beared permission under the Montreal (1987), Kyoto (1997) protocols, F‐Gas law (2015), Paris Accord (2016), and recent Kigali Amendment to Montreal Protocol (2019). In order to modify followed by the paradigm shift of existing heating and cooling systems, American Society of Heating, Refrigeration, and Air‐Conditioning Engineers (ASHRAE) envisaged natural and synthetic refrigerants (Synrefs) are under investigation globally. Carbon dioxide (CO2) is a popular natural refrigerant (Natref) replacing Synrefs used in commercial heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems globally. A rampant rise is observed in markets of Asia (Japan and China), North America (the United States and Canada), the Australian continent, and Africa (South Africa) by reaching 20 000 CO2‐stores around the globe. The European markets are leading the utilization of CO2 in the heat pump, and refrigeration, CO2 based markets estimate 14% of the total food retail stores (400 m2). Japan is the second leading market of CO2 heat pump and refrigeration with more than 10 200 CO2 condensing units. CO2 transcritical systems have a share of more than 10% in only European market (large stores); however, their share is less than 10% of total stores in other major markets of the world. New pump and compressor‐driven transcritical CO2 systems integrate ejectors, condensers, and booster systems to reduce energy consumptions, enhance efficiency, efficacy, and coefficient of performance. This article reports a critical review of the CO2 based heating, cooling, and refrigeration system and presents updated literature along with barriers and challenges on commercial use of Natref‐based heating and cooling applications worldwide.

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Section: History Of Refrigerantsmentioning

confidence: 99%

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

2019

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“…Cecchinato, Corradi and Minetto [29] suggested that a real-time algorithm for determining the optimal (or quasi-optimal) pressure value could provide a more efficient and robust solution. Minetto [30] first proposed a real-time control algorithm for a CO 2 heat pump water heater. In his approach, realtime estimation on COP required real compressor performance and additional assumptions.…”

Section: Introductionmentioning

confidence: 99%

Minimizing COP loss from optimal high pressure correlation for transcritical CO2 cycle

Liu

Cai

et al. 2015

Applied Thermal Engineering

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“…Minetto has conducted theoretical and experimental analysis on the performance of a water heater in consideration of the influence of inlet water temperature [25]. On the other hand, some studies have been conducted under unsteady states including charging and tapping modes: Fernandez et al have investigated the performance of a water heating system composed of a heat pump and a storage tank in the charging mode [26]; Yokoyama et al have conducted numerical simulations on such a system and have clarified the effects of the ambient and operation temperatures on system performance values under a daily cyclic change in hot water demand [27,28]; Yokoyama has conducted the exergy analysis of the system based on the results obtained by numerical simulation [29]; Yokoyama et al have also investigated daily changes in system performance values under daily changes in standardized and simulated hot water demands [30,31].…”

Section: Introductionmentioning

confidence: 99%

Numerical analysis on performance enhancement of a CO2 heat pump water heating system by extracting tepid water

Ohkura

Yokoyama

Nakamata

et al. 2015

Energy

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Water heating systems each of which is composed of an air-to-water heat pump using CO2 as a natural refrigerant and a hot water storage tank have been developed, and are expected to contribute to energy saving in residential hot water supply.However, the area of tepid water in the storage tank expands because of heat conduction during long time storage, which leads to a degradation of the system performance.One of the ways to reduce the area of tepid water and enhance the system performance is to extract tepid water from the side of the storage tank. In this paper, the performance enhancement of a CO 2 heat pump water heating system with such a revised storage tank is analyzed by numerical simulation. The simulation model developed previously for a conventional system is extended by modifying the model for the storage tank and verifying its validity through experiments. Through a performance analysis using a standardized hot water demand, it is clarified how system performance 2 values of the revised system are enhanced, and especially how the trade-off relationship between the system efficiency and the volume of unused hot water is improved, in comparison with those of the conventional system.

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Theoretical and experimental analysis of a CO2 heat pump for domestic hot water

Cited by 107 publications

References 23 publications

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

Minimizing COP loss from optimal high pressure correlation for transcritical CO2 cycle

Numerical analysis on performance enhancement of a CO2 heat pump water heating system by extracting tepid water

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Theoretical and experimental analysis of a CO2 heat pump for domestic hot water

Cited by 107 publications

References 23 publications

Review of carbon dioxide (CO 2 ) based heating and cooling technologies: Past, present, and future outlook

Review of carbon dioxide (CO 2 ) based heating and cooling technologies: Past, present, and future outlook

Minimizing COP loss from optimal high pressure correlation for transcritical CO2 cycle

Numerical analysis on performance enhancement of a CO2 heat pump water heating system by extracting tepid water

Contact Info

Product

Resources

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Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook

Review of carbon dioxide (CO ₂ ) based heating and cooling technologies: Past, present, and future outlook