Empirical Modeling of a Rolling-Piston Compressor Heat Pump for Predictive Control in Low-Lift Cooling
Inverter-driven variable-capacity air conditioners, heat pumps, and chillers can provide energy-efficient cooling, particularly at part-load capacity. Varying the capacity of vapor compression systems enables operation at lower pressure ratios, or low lift, which fundamentally improves the coefficie...
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American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)
2013
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Online Access: | http://hdl.handle.net/1721.1/80413 https://orcid.org/0000-0002-5631-7256 |
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author | Gayeski, Nicholas Zakula, Tea Armstrong, Peter R. Norford, Leslie Keith |
author2 | Massachusetts Institute of Technology. Department of Architecture |
author_facet | Massachusetts Institute of Technology. Department of Architecture Gayeski, Nicholas Zakula, Tea Armstrong, Peter R. Norford, Leslie Keith |
author_sort | Gayeski, Nicholas |
collection | MIT |
description | Inverter-driven variable-capacity air conditioners, heat pumps, and chillers can provide energy-efficient cooling, particularly at part-load capacity. Varying the capacity of vapor compression systems enables operation at lower pressure ratios, or low lift, which fundamentally improves the coefficient of performance of the system by reducing the required compressor work while providing a similar cooling effect. This is illustrated in Figure 1, which shows conventional and low-lift vapor compression cycles for refrigerant R22. A cycle with a lower condensing temperature, higher evaporating temperature, and/or slower compressor speed (the low-lift cycle) can achieve a similar (or even greater) cooling effect (the area below the evaporation process line) to that of the conventional cycle (the area inside the cycle polygon) with less compressor work.
The use of radiant cooling, precooling of thermal energy storage, and predictive control of compressor speed, condenser flow rate, and evaporator flow rate allow for low-pressure ratio, or low-lift, chiller operation (Armstrong et al. 2009a, 2009b) to meet daily cooling loads in a near-optimal manner. The combination of these strategies will here be called low-lift cooling. Radiant cooling requires moderate chilled-water temperatures, around 60 [degrees]F to 65 [degrees]F (15.5 [degrees]C to 18.3 [degrees]C), rather than about 44 [degrees]F (6.6 [degrees]C) for conventional systems, allowing for higher evaporating temperatures and pressures. Pre-cooling thermal energy storage allows night-time operation of a heat pump or chiller, providing lower condensing temperatures and pressures |
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id | mit-1721.1/80413 |
institution | Massachusetts Institute of Technology |
language | en_US |
last_indexed | 2024-09-23T15:43:21Z |
publishDate | 2013 |
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spelling | mit-1721.1/804132024-06-26T00:35:08Z Empirical Modeling of a Rolling-Piston Compressor Heat Pump for Predictive Control in Low-Lift Cooling Gayeski, Nicholas Zakula, Tea Armstrong, Peter R. Norford, Leslie Keith Massachusetts Institute of Technology. Department of Architecture Leslie Keith Norford Gayeski, Nicholas Zakula, Tea Armstrong, Peter R. Norford, Leslie Keith Inverter-driven variable-capacity air conditioners, heat pumps, and chillers can provide energy-efficient cooling, particularly at part-load capacity. Varying the capacity of vapor compression systems enables operation at lower pressure ratios, or low lift, which fundamentally improves the coefficient of performance of the system by reducing the required compressor work while providing a similar cooling effect. This is illustrated in Figure 1, which shows conventional and low-lift vapor compression cycles for refrigerant R22. A cycle with a lower condensing temperature, higher evaporating temperature, and/or slower compressor speed (the low-lift cycle) can achieve a similar (or even greater) cooling effect (the area below the evaporation process line) to that of the conventional cycle (the area inside the cycle polygon) with less compressor work. The use of radiant cooling, precooling of thermal energy storage, and predictive control of compressor speed, condenser flow rate, and evaporator flow rate allow for low-pressure ratio, or low-lift, chiller operation (Armstrong et al. 2009a, 2009b) to meet daily cooling loads in a near-optimal manner. The combination of these strategies will here be called low-lift cooling. Radiant cooling requires moderate chilled-water temperatures, around 60 [degrees]F to 65 [degrees]F (15.5 [degrees]C to 18.3 [degrees]C), rather than about 44 [degrees]F (6.6 [degrees]C) for conventional systems, allowing for higher evaporating temperatures and pressures. Pre-cooling thermal energy storage allows night-time operation of a heat pump or chiller, providing lower condensing temperatures and pressures Masdar Institute of Science and Technology Pacific Northwest National Laboratory (U.S.) Mitsubishi Electronic Research Laboratories 2013-09-12T16:02:32Z 2013-09-12T16:02:32Z 2010-10 Article http://purl.org/eprint/type/JournalArticle http://hdl.handle.net/1721.1/80413 Gayeski, Nicholas T.; Armstrong, Peter R.; Zakula, Tea; Norford, Leslie K. "Empirical modeling of a rolling-piston compressor heat pump for predictive control in low-lift cooling." ASHRAE Transactions, Vol. 116, No. 1. (2010). https://orcid.org/0000-0002-5631-7256 en_US http://www.thefreelibrary.com/Empirical+modeling+of+a+rolling-piston+compressor+heat+pump+for...-a0272754958 ASHRAE Transactions Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) MIT web domain |
spellingShingle | Gayeski, Nicholas Zakula, Tea Armstrong, Peter R. Norford, Leslie Keith Empirical Modeling of a Rolling-Piston Compressor Heat Pump for Predictive Control in Low-Lift Cooling |
title | Empirical Modeling of a Rolling-Piston Compressor Heat Pump for Predictive Control in Low-Lift Cooling |
title_full | Empirical Modeling of a Rolling-Piston Compressor Heat Pump for Predictive Control in Low-Lift Cooling |
title_fullStr | Empirical Modeling of a Rolling-Piston Compressor Heat Pump for Predictive Control in Low-Lift Cooling |
title_full_unstemmed | Empirical Modeling of a Rolling-Piston Compressor Heat Pump for Predictive Control in Low-Lift Cooling |
title_short | Empirical Modeling of a Rolling-Piston Compressor Heat Pump for Predictive Control in Low-Lift Cooling |
title_sort | empirical modeling of a rolling piston compressor heat pump for predictive control in low lift cooling |
url | http://hdl.handle.net/1721.1/80413 https://orcid.org/0000-0002-5631-7256 |
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