A study on the performance of multi-stage condensation heat pumps

Jung, Dongsoo; Lee, Yoonhak; Park, Byungjin; Kang, B.H.

doi:10.1016/s0140-7007(99)00083-3

Cited by 13 publications

(8 citation statements)

References 10 publications

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“…Optimum condensing temperature can be calculated easily in a few minutes with the help of practical formulae. A thorough search of the present literature showed that there were several studies about the HPS performance and optimization (Ubbels & Boumann 1979;NEI Projects Ltd 1983;Smith 1983;Wright & Steward 1985;Tyagi 1989;Kent 1997;Li 1999;Sahin & Kodal 1999;Salah El-Din 1999 ;Bourouis et al 2000 ;Jung et al 2000;Kodal et al 2001;Sahin B et al 2001;Kaushik et al 2002). All of these studies are not directly related to the present work.…”

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confidence: 89%

Operational cost minimization of heat pump for milk pasteurization in dairy

Söylemez

2005

Journal of Dairy Research

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A thermo economic optimization analysis is presented yielding simple algebraic formula for estimating the optimum operating conditions of interconnected heat pump assisted milk pasteurizing systems. The overall operational cost method including the cost of auxiliary heater is used in the present study, together with the thermal analyses of all system components, for thermo economic analysis of the system.

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mentioning

confidence: 89%

Operational cost minimization of heat pump for milk pasteurization in dairy

Söylemez

2005

Journal of Dairy Research

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“…The compressors and heat exchangers in parallel arrangement allow operating on a wider capacity range by switching on and off compressors and therefore tuning the refrigerant mass flows. Jung et al (2000) presented a promising concept for tap water heating with a three-stage condensation heat pump (see concept MC 7 with p-h diagram in Table 2). The cycle comprises a three-stage compressor and offers multiple heat sinks to best align the refrigerant temperature to the water temperature.…”

Section: Mc1 Inmentioning

confidence: 99%

“…Heat pumps are highly attractive energy conversion devices for the industry, since they offer efficient means to reduce primary energy consumption by utilizing heat recovery (Jung et al 2000).…”

Section: Introductionmentioning

confidence: 99%

“…Three-stage compressor (or multi-stage compressor) with three heat sinks for hot water production  1 multi-stage compressor  3 condensers (LT 2, MT, HT)  1 evaporator (LT 1)  Transcritical CO2 booster system possible  2 subcoolers (cooled by external water) (Jung et al, 2000) Water heating HT: 85°C MT: 73°C LT 2: 62°C LT 1: 50°C 3 sinks 1 source Multiple ejector CO2 cycle for refrigeration  3 or more (parallel) compressors  1 condenser/gas cooler  2 evaporators  1 liquid ejector  1 or more gas ejectors  2 accumulators  2 expansion valves (1 optional for highpressure) (Hafner et al, 2014;Schönenberger, 2014Schönenberger, , 2013 (Schönenberger, 2014(Schönenberger, , 2013 MEJ 4  CO2  I (Hafner et al, 2014) MEJ 4  CO2  D (Hill Phoenix, 2011) CAS 4   CO2 , HFC I Refrigeration (Baek et al, 2002) MC 4  CO2  S (Cecchinato et al, 2009) MC 4  CO2  S (Yari, 2009) MC 4  CO2  S (Sarkar, 2010) EJ 2  CO2  S (Yu et al, 2013) MEJ 3  R32 S Elbel, 2014, 2013) EJ 3  R134a, R1234yf S (Lin et al, 2012;Lino et al, 2013Lino et al, , 2012 MEJ (Jung et al, 2000) MC 7  R123, R141b S (Zehnder et al, 1999) CAS 1  R407C, others S, D (Kondou and Koyama, 2014) CAS 2  R1234ze, R365mfc S (Neksa, 2002) SGC 1  CO2  D (Stene, 2005) SGC 1  CO2  S, D (Blanco et al, 2013a) SGC 2  R410A D …”

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confidence: 99%

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Multi-temperature heat pumps: A literature review

Arpagaus

Bless

Schiffmann

et al. 2016

International Journal of Refrigeration

113

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Please cite this article as: Cordin Arpagaus, Frédéric Bless, Jürg Schiffmann, Stefan S. Bertsch, Multi-temperature heat pumps -A literature review, International Journal of Refrigeration (2016), http://dx.doi.org/Highlights (3-5 bullets, max. 85 characters including spaces):  A review on multi-temperature heat pumps and refrigeration systems is given.  Design strategies for multi-temperature heat pumps are presented.  Application examples in refrigeration, air-conditioning and heating are discussed.  First Law and Second Law efficiencies of the cycles are calculated based on thermodynamic models. AbstractThis review highlights the major advantages and challenges of mechanically driven heat pumps and refrigeration systems with focus on multi-temperature applications. Different design strategies are presented, including cycles with multi-stage compressors, ejectors, expansion valves, cascades, and separated gas coolers. Most multitemperature heat pump cycles use two heat sources and one heat sink. In supermarket applications, multi-stage compressor cycles with transcritical CO2 is an established key technology. Cascades with secondary loops are another frequently applied type of system. Expansion valve cycles are applied in household refrigeration and air conditioning. Cycles with ejectors seem to be a promising modification for system performance improvement. Separated gas coolers for space heating and hot water production have recently attracted attention due to the possible combination with supercritical CO2 cycles. Thermodynamic simulations reveal that multi-stage compressor cycles have the highest COPs and Second Law efficiencies, followed by cascade, ejector, and expansion valve cycles. The baseline cycle consisting of two single-stage heat pumps in parallel shows lower Second Law efficiency than the multi-stage compressor and cascade cycles, and higher efficiency than the ejector and expansion valve cycles.

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“…Payne [4] also measured the refrigeration and heating capacities of a heat pump with R32/R290, R32/R152a, and R290/R600a. Jung et al [5] studied the performance of multi-stage heat pumps using R11, R123, and R141b with the water temperature raised 50-85°C. Li et al [6] tested the performance of a heat pump with R22/R141b at an output temperature of 80°C.…”

Section: Introductionmentioning

confidence: 99%