Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Social and Behavioral Sciences (11626)
- Library and Information Science (8974)
- Engineering (6329)
- Physical Sciences and Mathematics (2868)
- Arts and Humanities (2752)
-
- Civil and Environmental Engineering (2550)
- Computer Sciences (2077)
- Education (1983)
- Civil Engineering (1879)
- Life Sciences (1669)
- Comparative Literature (1407)
- Communication (854)
- Medicine and Health Sciences (725)
- Rhetoric and Composition (694)
- Feminist, Gender, and Sexuality Studies (680)
- American Studies (667)
- Film and Media Studies (638)
- Mechanical Engineering (619)
- European Languages and Societies (607)
- Reading and Language (606)
- Critical and Cultural Studies (594)
- Agriculture (585)
- Other Arts and Humanities (585)
- Psychology (552)
- Plant Sciences (546)
- Nanoscience and Nanotechnology (541)
- Theatre and Performance Studies (539)
- Other Film and Media Studies (522)
- Television (509)
- Business (488)
- Keyword
-
- Applied sciences (587)
- Comparative literature (498)
- comparative literature (488)
- Comparative cultural studies (303)
- comparative cultural studies (297)
-
- Education (220)
- Social sciences (205)
- Biological sciences (195)
- Information literacy (170)
- Pure sciences (160)
- Cultural studies (155)
- Simulation (154)
- Vegetables (153)
- cultural studies (152)
- Variety trials (147)
- Literary theory (136)
- literary theory (135)
- Construction (120)
- Optimization (118)
- Health and environmental sciences (117)
- Sustainability (106)
- CFD (95)
- Safety (94)
- Economics (92)
- Problem-based learning (92)
- Zea mays (92)
- Modeling (90)
- Mechanics (87)
- Concrete (86)
- Heat transfer (85)
- Publication Year
- Publication
-
- Against the Grain (7173)
- Purdue Road School (3846)
- International Compressor Engineering Conference (2764)
- International Refrigeration and Air Conditioning Conference (2681)
- Open Access Dissertations (2120)
-
- JTRP Technical Reports (1905)
- Department of Computer Science Technical Reports (1777)
- Open Access Theses (1616)
- CLCWeb: Comparative Literature and Culture (1418)
- Proceedings of the IATUL Conferences (1358)
- Historical Documents of the Purdue Cooperative Extension Service Archive (1121)
- Department of Physics and Astronomy Faculty Publications (1038)
- The Writing Center Journal (1028)
- Charleston Library Conference (939)
- The Summer Undergraduate Research Fellowship (SURF) Symposium (884)
- Department of Electrical and Computer Engineering Technical Reports (747)
- The Journal of Purdue Undergraduate Research (683)
- Society of Engineering Science 51st Annual Technical Meeting Archive (652)
- First Opinions, Second Reactions (609)
- CIB Conferences (503)
- International High Performance Buildings Conference (495)
- LARS Symposia (491)
- Birck and NCN Publications (488)
- Education and Culture (431)
- International Conference on Durability of Concrete Structures (359)
- CTRC Research Publications (353)
- Libraries Faculty and Staff Scholarship and Research (294)
- Midwest Vegetable Trial Reports (288)
- Publications of the Ray W. Herrick Laboratories (286)
- Journal of Southeast Asian American Education and Advancement (274)
- Publication Type
Articles 6391 - 6420 of 50088
Full-Text Articles in Entire DC Network
A Model Of Heat Exchangers And Automotive Ac System With Refrigerant-Oil Mixtures, Yongfang Zhong, Arpit Tiwari, Abhishek Jain, Mihail Spasov
A Model Of Heat Exchangers And Automotive Ac System With Refrigerant-Oil Mixtures, Yongfang Zhong, Arpit Tiwari, Abhishek Jain, Mihail Spasov
International Refrigeration and Air Conditioning Conference
We present the method to simulate refrigerant-oil mixtures (Thome 1995) via a one-dimensional (1D) transient multi-physics system-level simulation tool, GT-SUITE. The impact of oil on bubble point and evaporation enthalpy is first validated, followed by the comparison of the predicted heat transfer coefficient and friction factor with the data by Zurcher et al. (1997). A system model of an automobile air-conditioning (AC) system is developed and validated using experimental data by Liu and Hrnjak (2016). The predicted evaporator capacity and system coefficient of performance (COP) matches very well with the data (both have an average error of 1.4% and the …
Comprehensive Modeling Of A Chemical Looping Heat Pump With A Reverse Fuel Cell, Junyoung Kim, Nelson A. James, James E. Braun, Eckhard A. Groll, Davide Ziviani
Comprehensive Modeling Of A Chemical Looping Heat Pump With A Reverse Fuel Cell, Junyoung Kim, Nelson A. James, James E. Braun, Eckhard A. Groll, Davide Ziviani
International Refrigeration and Air Conditioning Conference
HVAC, refrigeration, and water heating accounted for approximately 22 quads of primary energy consumed in the United States in 2018, according to US EIA. Most of HVAC&R industry still relies on vapor compression and heat-driven technologies. The development of highly efficient technologies that would significantly improve both COP and annual energy savings is an open challenge for the new decade. Among the novel technologies, the Chemical Looping Heat Pump (CLHP) combined with a reverse fuel cell has been modeled with estimates of a COP increase of over 20% relative to a conventional vapor compression (VC) cycle. However, limitations of simplified …
Efficient Simulation Method For Parallel Tube Evaporators For Vehicle Battery Cooling, Bernhard Einberger, Christoph Zainer, Andreas Ennemoser, Sebastian Möller, Andreas Egger, Michael Lang
Efficient Simulation Method For Parallel Tube Evaporators For Vehicle Battery Cooling, Bernhard Einberger, Christoph Zainer, Andreas Ennemoser, Sebastian Möller, Andreas Egger, Michael Lang
International Refrigeration and Air Conditioning Conference
Due to its size, the cooling of a vehicle battery by means of a refrigeration system has to be implemented e.g. via parallel evaporator tubes. After the throttle, the two-phase refrigerant flow must be uniformly distributed into several cooling channels so that uniform cooling can be achieved throughout the entire volume. The simulation of the three-dimensional effects in the distributor and also in the collector of an evaporator with several parallel evaporator tubes can only be done by computational fluid dynamics (3D CFD). However, the 3D CFD simulation of the evaporator is time consuming and can be replaced by a …
Experimental Analysis Of A Draft Beer Ice Bank Machine, Santiago Torras, Carles Oliet, Joaquim Rigola, Carlos-David Pérez-Segarra
Experimental Analysis Of A Draft Beer Ice Bank Machine, Santiago Torras, Carles Oliet, Joaquim Rigola, Carlos-David Pérez-Segarra
International Refrigeration and Air Conditioning Conference
In a long-term established application as draft beer cooling and servicing machines, seems difficult to see any research application at first sight. However, this perspective change when one considers that the costs associated to maintenance/operating problems are very high for breweries with a very extensive network of machines. Moreover, the strong competitive market among different companies means that any cooling failure could be an opportunity for the competence. An additional aspect to consider, is that the climate and installation variability among different machines asks for a complete a-priori understanding of the unit behavior under integrated operating conditions, in order to …
Experimental And Theoretical Analysis Of Subcooling Control In Residential Air Conditioning Systems, Bruno Yuji Kimura De Carvalho, Pega Hrnjak
Experimental And Theoretical Analysis Of Subcooling Control In Residential Air Conditioning Systems, Bruno Yuji Kimura De Carvalho, Pega Hrnjak
International Refrigeration and Air Conditioning Conference
Widespread use of electronic expansion valves in residential air conditioning systems has provided an opportunity to further improve performance by use of alternative refrigerant flow control strategies. This paper focuses on an experimental and theoretical investigation on the effect of subcooling control in air conditioning system. A 2 Ton (7 kW) R410-A system was used in the experimental study and a model for the same system was developed and validated. The paper provides a theoretical analysis and determination of a control scheme to maximize COP and an experimental validation on the performance of a RAC system with subcooling control against …
Numerical Analysis For Heat Driven Ejector Refrigeration Systems For Various Refrigerants, Tokitaka Yoshida, Takeshi Matsubara, Masaaki Ajima, Masamichi Iwasaki, Stefan Elbel
Numerical Analysis For Heat Driven Ejector Refrigeration Systems For Various Refrigerants, Tokitaka Yoshida, Takeshi Matsubara, Masaaki Ajima, Masamichi Iwasaki, Stefan Elbel
International Refrigeration and Air Conditioning Conference
In this study, a numerical efficiency analysis for ejector refrigeration systems driven by low grade waste heat (65-85 °C) is performed. A 1-D numerical ejector model which was validated is applied to estimate the characteristics of the ejector. Investigation is focused on various refrigerants such as HFC (R134a, R245fa, R365mfc), HFO (R1234yf, R1234ze(E), R1233zd(E), R1336mzz(Z)), and natural refrigerants (NH3, R600, R600a), and their COPs (Coefficient of Performance) are compared. Main operating conditions (e.g. generation temperature, evaporation temperature, condensation temperature) are also considered to compare the system characteristics for each refrigerant. Simulations are performed for different operating conditions and their effects …
Applying Two-Phase Zeotropic Heat Transfer Fluids To Solid-State Cooling Cycle And Comparison With Baseline Using Single Phase Water, Minwoong Kang, Stefan Elbel
Applying Two-Phase Zeotropic Heat Transfer Fluids To Solid-State Cooling Cycle And Comparison With Baseline Using Single Phase Water, Minwoong Kang, Stefan Elbel
International Refrigeration and Air Conditioning Conference
Solid-state caloric cooling cycles are considered to be a promising alternative to conventional cooling technology. Theoretically, they can compete with the conventional vapor compression cycle and are much more efficient. However, this technology does have one problem: its performance decreases rapidly if the temperature difference between the condenser and evaporator gets larger. The environment where cooling technology is used often has large temperature differences between condenser and evaporator. For instance, in a typical automotive system, the condenser operates at 45°C and the evaporator at 5°C. Thus, the temperature difference between the condenser and evaporator reaches 40°C. The cooling load of …
Numerical Simulation Of Ice Slurry Flow In Improved Plate Heat Exchanger Geometries With Consideration Of Different Phase Interaction Parameters, Shaimaa Hefny Badawi, Christiane Thomas, Ullrich Hesse
Numerical Simulation Of Ice Slurry Flow In Improved Plate Heat Exchanger Geometries With Consideration Of Different Phase Interaction Parameters, Shaimaa Hefny Badawi, Christiane Thomas, Ullrich Hesse
International Refrigeration and Air Conditioning Conference
Concerning the cold supply, ice slurry technology is a safe, environmentally friendly and efficient solution for energy storage. Previous studies have shown that ice slurry is potentially one of the most important phase change material (PCM) slurries used as a secondary refrigerant due to its high cooling capacity and flexibility in application. However, agglomeration phenomena are observed with ice particle slurry flows, which can lead to blocking of e.g. heat exchangers and pipes. The study applies an Euler-Euler approach based on the kinetic theory of granular flow to describe the melting of an ice slurry flow. The Eulerian model was …
Investigation Of Pressure Drop In Refrigerant Pipes Of An Automotive Air Conditioning System, Robin Meinert, Gerhard Schmitz
Investigation Of Pressure Drop In Refrigerant Pipes Of An Automotive Air Conditioning System, Robin Meinert, Gerhard Schmitz
International Refrigeration and Air Conditioning Conference
This paper presents an experimental and numerical investigation of the pressure drop of automotive refrigerant pipes. The measurement is done with a test rig that is able to set a defined one-or two-phase state at the inlet of an exchangeable test section. With the experimental data, CFD simulations are validated. There is a liquid and a hot gas line being investigated in this work. It turns out that transition pieces between pipe and hose elements have a significant influence on the pressure drop. Although the connection technology is the same, it must always be checked how the internal structure of …
Permeability Analysis Of Additively-Manufactured Wick Structures With Heat Exchanger Applications, Jordan Alexander Morrow, Carlos Espino Mendez, Melanie M Derby
Permeability Analysis Of Additively-Manufactured Wick Structures With Heat Exchanger Applications, Jordan Alexander Morrow, Carlos Espino Mendez, Melanie M Derby
International Refrigeration and Air Conditioning Conference
Heat pipes and other heat transfer applications use capillary-driven liquid motion to enhance performance. This research uses water and a low surface tension fluid FC-40 to test additive-manufactured polymer wicks using a rateof-rise test. The rate-of-rise tests give a measure of the wicks’ performance capabilities as well as being able to calculate the wicks’ permeability and effective pore radius. Four wicks were measured having two different internal structures (i.e., 1.0 mm triangle and 1.75 mm square) and two external structures (i.e., layered and column). The 1.0 mm Triangle wicks performed better than their 1.0 mm Square counterparts for both water …
Characterization Of Solid Desiccant For Dehumidification Applications, Kashif Nawaz, Omar Abdelaziz, Anthony Jacobi
Characterization Of Solid Desiccant For Dehumidification Applications, Kashif Nawaz, Omar Abdelaziz, Anthony Jacobi
International Refrigeration and Air Conditioning Conference
Solid desiccant-based dehumidification systems have been considered extensively for separate sensible and latent cooling systems. The performance of overall system heavily depends on the desiccant characteristics. The objective of the current study is to investigate the steady state and transient properties of a solid desiccant systems. Test schemes have been proposed to investigate the performance of desiccants where samples are exposed to various humidity conditions. The moisture adsorption and desorption behaviors have been evaluated and the data has been used to establish moisture adsorption and desorption isotherms at various temperature. Along with steady state performance, transient behavior has been investigated …
An Updated Quantification Method For Liquid Refrigerant Distribution In Microchannel Evaporators Using Infrared Thermography, Yuping Gao, Daniel Silsbee, Ke Tang, Stefan Elbel
An Updated Quantification Method For Liquid Refrigerant Distribution In Microchannel Evaporators Using Infrared Thermography, Yuping Gao, Daniel Silsbee, Ke Tang, Stefan Elbel
International Refrigeration and Air Conditioning Conference
Refrigerant distribution in the parallel tubes of a microchannel evaporator significantly affects its heat transfer performance, which can further affect the coefficient of performance of the whole air-conditioning or refrigeration system. This paper proposes an easy-to-implement quantification method using infrared thermography for the liquid refrigerant distribution in microchannel evaporators to update the original method developed by Li and Hrnjak (2015). Before the detailed discussion of the new quantification method, the effect of surface emissivity on the infrared thermography is investigated, and the calibration process of the infrared thermography is presented for a microchannel heat exchanger sample. Then, the updated quantification …
Performance Evaluation Of A Flooded Ice Rink Chiller Retrofit From R-22 To R-449a, David Snyder, Charles Allgood, Tim Mcrae
Performance Evaluation Of A Flooded Ice Rink Chiller Retrofit From R-22 To R-449a, David Snyder, Charles Allgood, Tim Mcrae
International Refrigeration and Air Conditioning Conference
The selection criteria of working fluids for industrial refrigeration, dictated by both safety and environmental factors, has evolved continuously since the advent of refrigerant technology. With each advancement in working fluid class, considerations are made around the compatibility with regards to retrofitting existing equipment. This is still the case for the transition to HFO blends. The combination of the R-22 phase out with a large majority of well-maintained R22 ice rink chillers currently in operation creates a need for a retrofit gas that will meet or exceed existing performance criteria while complying with current regulatory requirements. However, it has long …
Impact Of Mechanical Ventilation And Indoor Air Recirculation Rates On The Performance Of An Active Membrane Energy Exchanger System, Andrew Fix, James Braun, David Warsinger
Impact Of Mechanical Ventilation And Indoor Air Recirculation Rates On The Performance Of An Active Membrane Energy Exchanger System, Andrew Fix, James Braun, David Warsinger
International Refrigeration and Air Conditioning Conference
As concern for indoor air quality grows, many buildings will likely opt to provide higher rates of outdoor air than would traditionally be specified. This imposes a challenge on air conditioning systems since the latent loads associated with ventilation air are much higher than those associated with recirculated air. Membrane-based technologies, which enable mechanical separation of water vapor from air, have recently emerged as promising candidates for efficiently providing dehumidification, however, limitations remain. To date, most modeling work on these types of systems has focused on 100% outdoor air configurations that employ isothermal dehumidification designs. However, we have proposed a …
Heat Transfer Enhancement Of Falling Film Evaporation Of Hfo-1233zd(E) And Hfc-134a On A Horizontal Tube By Thermal Spray Coating, Tsutomu Ubara, Katsumi Sugimoto, Hitoshi Asano
Heat Transfer Enhancement Of Falling Film Evaporation Of Hfo-1233zd(E) And Hfc-134a On A Horizontal Tube By Thermal Spray Coating, Tsutomu Ubara, Katsumi Sugimoto, Hitoshi Asano
International Refrigeration and Air Conditioning Conference
A falling film evaporator can reduce the amount of refrigerant compared with a flooded evaporator. Required functions for the heat transfer surface in falling liquid film evaporation are thin liquid film formation without breaking at low heat flux, nucleate boiling promotion in liquid film, and suppression of liquid entrainment at high heat flux. In this study, a porous thermal spray coating using copper as the coating material was made on a copper cylinder. The heat transfer performance of falling film evaporation and pool boiling was evaluated using HFO1233zd(E) as the refrigerant, and the obtained results were compared with those for …
A Study On Computational Cost Reduction Of Simulations Of Phase-Change Material (Pcm) Embedded Heat Exchangers, Daniel Bacellar, Tanjebul Alam, Jiazhen Ling, Vikrant Aute
A Study On Computational Cost Reduction Of Simulations Of Phase-Change Material (Pcm) Embedded Heat Exchangers, Daniel Bacellar, Tanjebul Alam, Jiazhen Ling, Vikrant Aute
International Refrigeration and Air Conditioning Conference
Thermal storage can be implemented using Phase-Change Materials (PCM), which absorb significant latent heat with a relatively small temperature change. PCM phase-change processes are transient and are driven by thermal diffusion and natural convection – the latter, especially for melting process. Modeling and simulation of PCM heat exchangers (HX’s) is typically computationally intensive due to the relatively complex time-dependent physics. Most of the PCM modeling work in the literature uses high-order modeling tools such as Computational Fluid Dynamics (CFD) and Lattice-Boltzmann Method (LBM). For design purposes, the existing PCM modeling approaches are not practical, limiting researchers in their ability to …
Research On Oil Circulation Rate Of Co2 Inverter Rotary Compressors, Li Li, Min Sun
Research On Oil Circulation Rate Of Co2 Inverter Rotary Compressors, Li Li, Min Sun
International Compressor Engineering Conference
The oil circulation rate(OCR) of a CO2 inverter rotary compressor is higher than expected. The computational fluid dynamics(CFD) method is used to build a flow field simulation model of the compressor. Boundary conditions are determined according to the real running conditions of the compressor, involving the pressure, the temperature, the mass flow rate and other necessary parameters. There are four paths for refrigeration gas and oil flowing across: the motor rotor channel, the air gap between the motor rotor and the motor stator, the winding gap and the motor stator core cut. The CO2 mass flow rates of these four …
Comparative Studies Of Scroll And Rotary Compressors For Us Market Heat Pumps And Air Conditioners, Song Li, James Carow, Daniel Bacellar, Cara Martin
Comparative Studies Of Scroll And Rotary Compressors For Us Market Heat Pumps And Air Conditioners, Song Li, James Carow, Daniel Bacellar, Cara Martin
International Compressor Engineering Conference
Rotary compressors have long been developed and adopted for heating, ventilation, and air-conditioning (HVAC) applications across Asia, primarily due to their simpler mechanism and fewer parts as compared to their counterparts such as scroll compressors. However, rotary compressors in heat pumps (HPs) and air conditioners (ACs) in the US have limited market share and are often confined to systems smaller than 3.0 tons (10.6 kW). This paper consists of two parts; the first is on rotary compressor technology and its advantages and disadvantages from both technical and market standpoints. The review consists of a survey of the literature, as well …
Horizontal Scroll Compressor For Refrigeration Applications, Mikhail A. Antimonov, Michael M. Perevozchikov, Kirillm. Ignatiev
Horizontal Scroll Compressor For Refrigeration Applications, Mikhail A. Antimonov, Michael M. Perevozchikov, Kirillm. Ignatiev
International Compressor Engineering Conference
New efficiency regulations, as well as trends in applications of new low GWP refrigerants, force compressors to be re-designed, especially for A3 refrigerants, because of the regulatory limitations of the refrigerant charge. The paper addresses compressor design allowing for more efficient use of the refrigerant charge. An oil sump retains significant amount of refrigerant diluted in the oil. Elimination of the oil sump allows to use the limited refrigerant charge more effectively. Furthermore, it reduces the size of the compressor and simplifies the compressor structure. Another benefit of this type of compressor is its orientation flexibility-the same compressor can be …
Design Optimization For Discharge Valve In A Rotary Compressor, Joonhyung Kim, Munseong Kwon, Hyolim Heo
Design Optimization For Discharge Valve In A Rotary Compressor, Joonhyung Kim, Munseong Kwon, Hyolim Heo
International Compressor Engineering Conference
Rotary compressor used for refrigerant compression is the core equipment for room air conditioners(RACs). For an energy efficient RACs, energy efficiency metrics is moving to seasonal performance evaluation. And the compressor efficiency at low load conditions is getting more important than high load conditions. Therefore, compression efficiency under low load conditions is a major indicator of overall operational efficiency. This paper presents a design optimization procedure to improve the efficiency of a rotary compressor under low load condition using response surface method(RSM) and fluid-structure interaction(FSI) technique. Three shape dimensions associated with the discharge valve system were selected as design parameters, …
Research On Noise Reduction Of Variable Speed Rotary Compressor With Large Capacity, Haijun Wang, Zhibin Xie, Yinxiao Lu, Weiyan Chu, Zheng Li
Research On Noise Reduction Of Variable Speed Rotary Compressor With Large Capacity, Haijun Wang, Zhibin Xie, Yinxiao Lu, Weiyan Chu, Zheng Li
International Compressor Engineering Conference
With the increasing speed and capacity of variable-speed rotary compressors, the problem of noise especially low and medium frequency noise in the air conditioning system which can't be solved by wrapping soundproof cotton has became more serious. In this paper, based on the noise problem of the rotor compressor with a working capacity of more than 80CC, the main frequency and the position of the noise source within 1000Hz are confirmed by simulation and experiment. Then on the base of this，the muffler and accumulator are respectively optimized and improved combining with Computer Aided Engineering (CAE) means. The final application results …
A Study Of "Oval" Scroll Compressor For Capacity Increase, Wataru Iwatake, Raito Kawamura, Keisuke Narumi, Daisuke Kudo
A Study Of "Oval" Scroll Compressor For Capacity Increase, Wataru Iwatake, Raito Kawamura, Keisuke Narumi, Daisuke Kudo
International Compressor Engineering Conference
In recent years, there has been demand for a large-capacity scroll compressor to reduce cost and improve performance. To increase the capacity of the scroll compressor, technology to expand the stroke volume without increasing the shell size is required. To expand the stroke volume, expanding the wrap height in the axial direction is most effective. However, the higher wrap height raises the stress on the wrap and causes the orbiting scroll to overturn. So, we started to study a new shape of wrap to expand the stroke volume in the horizontal direction. The base plate of an orbiting scroll is …
Study On The Performance Of Co2 Two-Stage Rotary Compressor In Freezing And Cold Storage Conditions, Yusheng Hu, Huijun Wei, Jia Xu, Liping Ren, Peng Zou
Study On The Performance Of Co2 Two-Stage Rotary Compressor In Freezing And Cold Storage Conditions, Yusheng Hu, Huijun Wei, Jia Xu, Liping Ren, Peng Zou
International Compressor Engineering Conference
This paper describes a new type CO2 two-stage rotary compressor for cold storage and freezing of food. A two-stage compression form with an upper cylinder (first-stage) and a lower cylinder (second-stage), unique oil road structures and technical parameters have been used in the rotary compressor to increase the performance. The results indicating that the optimized CO2 two-stage rotary compressor has a significant performance advantage, which the coefficient of performance (COP) increases by 4.4% ~ 6.7%.
Parametric Studies On A New Schukey Type Rotary Compressor, Bin Cui, Martin Gottschlich, Ulrich Lüdersen, Stephan Kabelac
Parametric Studies On A New Schukey Type Rotary Compressor, Bin Cui, Martin Gottschlich, Ulrich Lüdersen, Stephan Kabelac
International Compressor Engineering Conference
Efficient compressors are generally important for applications in air conditioning and refrigeration systems. Therefore, innovative technologies are needed to improve their performance and expand their area of application. A new type of rotary compressor, called “Schukey compressor”, has been investigated both experimentally and theoretically. The Schukey-technology goes back to its founder Jürgen Schukey in 1987, who invented a special gear that enables two rotors to rotate out of phase in the same direction within the compressor housing. Each rotor consists of four rectangular shaped piston wings that interlock and perform non-uniform rotary movements, leading to a periodic change of the …
Development Of Large-And-Small Volume-Switching Rotary Compressor For Residential Multi-Connected Air-Conditioner, Mingzhu Dong, Yusheng Hu, Huijun Wei, Jia Xu, Peizhen Que, Yanjun Hu
Development Of Large-And-Small Volume-Switching Rotary Compressor For Residential Multi-Connected Air-Conditioner, Mingzhu Dong, Yusheng Hu, Huijun Wei, Jia Xu, Peizhen Que, Yanjun Hu
International Compressor Engineering Conference
Residential Multi-Connected Air-Conditioner(RMAC) are widely used in urban residential in China, but they have low energy efficiency problems in daily use. They are mainly due to the air-conditioning habits of Chinese residents in "part space and part time", Which makes RMAC most of the time only 1-2 indoor units are turned on, and 60% of the operating time is at a low load rate of less than 30%. During low load operation, the compressor's efficiency drops sharply, and there is also the problem of frequent start and stop when the minimum output is too large. In order to solve this …
Experimental Comparison Of Seasonal Performance In R410a Chiller Using Single Speed And Two Stage Compressor, Sugun Tej Inampudi, Francesco Botticella, Stefan Elbel
Experimental Comparison Of Seasonal Performance In R410a Chiller Using Single Speed And Two Stage Compressor, Sugun Tej Inampudi, Francesco Botticella, Stefan Elbel
International Compressor Engineering Conference
Rising cooling needs for the residential and commercial air conditioning sectors and the requirement of higher SEER values increased the focus on energy-efficient part load performance. Although several studies exist on the topic of capacity modulation, there is no comprehensive study that compares different modulation strategies in the same experimental facility. In a first step, this paper aims to experimentally compare two different capacity controls for scroll compressors (single speed vs two-stage compressor) using the same R410A water ethylene glycol (WEG) chiller having a nominal cooling capacity of 8kW. The tests were conducted according to AHRI Standard 551/591 (2018). The …
A Critical Analysis Of The Characterization Of Scroll Compressors Energy Consumption, Javier Marchante-Avellaneda, Jose Miguel Corberan, Emilio Navarro-Peris, Som S. Shrestha
A Critical Analysis Of The Characterization Of Scroll Compressors Energy Consumption, Javier Marchante-Avellaneda, Jose Miguel Corberan, Emilio Navarro-Peris, Som S. Shrestha
International Compressor Engineering Conference
This paper presents the analysis of the energy consumption of scroll type compressors. The study has included the data of several AHRI reports: (especially AHRI-11 and AHRI-21) as well as data from other source. A total of 8 different scroll compressors, of different size, some of them tested with various refrigerants (R134a, R32, R410A, R404A…) have been considered in the study. The values of the compressor consumption, and of the corresponding compressor efficiency, and the shape of the corresponding response surfaces, for all the studied compressors and refrigerants, have been analyzed with the objective of understanding better the dependence of …
Development Of A New Dual-Cylinder Rolling Piston Compressor, Li Zhang, Chunhui Liu, Ruixiong Wang, Lei Zhang
Development Of A New Dual-Cylinder Rolling Piston Compressor, Li Zhang, Chunhui Liu, Ruixiong Wang, Lei Zhang
International Compressor Engineering Conference
In recent years, the requirement of energy efficiency for refrigeration and air condition systems becomes more and more higher while the cost needs to be more and more lower, at the same time some new applications of refrigeration and air condition systems are emerging rapidly. All of these demands need a new compressor to meet. In this paper, a new dual-cylinder rolling piston compressor with two independent suction ports and two independent discharge ports was proposed. The structure and working principal of this compressor were described, and the performance was tested. Then simulation model was built to research the performance …
Performance Comparison Between Rolling Piston And Coupled Vane Compressor, Qi Jing Chen, Kim Tiow Ooi
Performance Comparison Between Rolling Piston And Coupled Vane Compressor, Qi Jing Chen, Kim Tiow Ooi
International Compressor Engineering Conference
In this paper, the performance of the rolling piston compressor and the coupled vane compressor are compared, and differences or similarities are presented and discussed. The comparison is based on one of the available sizes of the rolling piston compressor as used in a room air-conditioner. The extent of the theoretical comparison includes their respective design features, relative sizes, individual flow and frictional energy losses, details of PV diagrams, valve flow analysis and other performance parameters such as “compressor” COP. The coupled vane compressor is a novel compressor recently design with the objective to save raw materials in the production …
A Unified Mpc Formulation For Control Of Commercial Hvac Systems In Multiple Climate Zones, Naren Srivaths Raman, Bo Chen, Prabir Barooah
A Unified Mpc Formulation For Control Of Commercial Hvac Systems In Multiple Climate Zones, Naren Srivaths Raman, Bo Chen, Prabir Barooah
International High Performance Buildings Conference
Model predictive control (MPC) has been widely investigated for climate control of commercial buildings for both energy efficiency and demand flexibility. However, most MPC formulations ignore humidity and latent heat. The inclusion of moisture makes the problem considerably more challenging, primarily since a cooling and dehumidifying coil model which accounts for both sensible and latent heat transfers is needed. In our recent work, we proposed an MPC controller in which humidity and latent heat were incorporated in a principled manner, by using a reduced-order model of the cooling coil. Because of the highly nonlinear nature of the process in a …