Expansion Valve

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Performance Analysis of Electronic Expansion Valve in 1 TR Window Air Conditioner using Various Refrigerants

Performance Analysis of Electronic Expansion Valve in 1 TR Window Air Conditioner using Various Refrigerants

To have a maximum COP, full charge condition was determined under a standard condition of condenser temperature at 323 K and evaporator temperature 279 K. By keeping the temperature of refrigerant entering the evaporator at 279K and varying its temperature at inlet to condenser as 313K, 318K, 323K and 328K, the tests for the window air conditioner using the refrigerantsR22 and R 407C with various expansion devices such as capillary tube, thermostatic expansion valve and EEV were conducted by setting the same full charge condition for all the three expansion devices and corresponding readings were recorded continuously for 40 minutes using the data acquisition system The refrigerant effect, compressor power and COP were calculated and results for R22and R407C were analyzed. Heat infiltration load into indoor chamber was determined. Again tests were conducted by varying the refrigerant super heat temperature at inlet to the compressor from 273K to 293K in steps of 2K by adjusting the EEV .The indoor and outdoor conditions were maintained by adjusting the power supply to the heaters and controlling the humidifiers. Refrigerant side and airside readings were noted and for better accuracy, the average values were used for computing various performance parameters. For calculating the refrigeration effect and compressor power, the enthalpy values of refrigerant at salient points were obtained from the refrigerant’s thermodynamic property value tables using the pressure and temperature readings .All the three refrigerantsR22,R 407C and R290 under study were tested using electronic expansion valve alone and results were analyzed.

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Temperature distribution of R 134a through 
		aluminum and PTFE expansion valve on automotive air conditioning 
		applications

Temperature distribution of R 134a through aluminum and PTFE expansion valve on automotive air conditioning applications

From Table-1 and Table-2, the enthalpy difference (Δh) in the expansion valve made of aluminum is 152.46 kJ/kg (408.77 kJ/kg - 256.31 kJ/kg). Meanwhile, the enthalpy difference (Δh) in the expansion valve made of PTFE is 155.49 kJ/kg (404.43 kJ/kg – 248.94 kJ/kg). With the same refrigerant mass flow, this means the expansion valve made of PTFE generates potential heat absorption greater than the expansion valve made of aluminum (3.03 kJ/kg). Approaches for explaining this condition, PTFE has a very low thermal conductivity, so the heat loss in the expansion process can be reduced. 4. CONCLUSIONS

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A Controller Design For An Expansion Valve

A Controller Design For An Expansion Valve

The expansion valve is adjustable and controls the Freon flow through the system (and the pressure difference between the two sides). The inlet side of the valve is at high pressure and the Freon is a room temperature liquid at this location. In the expansion process, the pressure drops rapidly to the low pressure value and the Freon is superheated in this new pressure condition. The material then undergoes a partial change of phase, using its internal energy to provide the heat of transformation from the liquid to vapor phase. The reduction in internal energy is associated with a decrease in temperature of the two phase material exiting from the expansion valve.

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Review on Comparative Analysis of COP of Vapour Compression Refrigeration System

Review on Comparative Analysis of COP of Vapour Compression Refrigeration System

The evaporator is used in the low vapour side of refrigeration system. The liquid refrigerant from the expansion valve enters in to the evaporator where it boils and changes in to vapour. The function of evaporator is absorbing heat from the surrounding location of medium which is cooled, by means of refrigerant. A simple refrigerant circuit is built up as shown in the sketch below. In what follows, the individual components are described to clarify a final overall picture[10]. A refrigerant in liquid form will absorb heat when it evaporates and it is this conditional change that produces cooling in a refrigerating process.

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Review on Comparative Analysis of COP of Vapour Compression Refrigeration System

Review on Comparative Analysis of COP of Vapour Compression Refrigeration System

The evaporator is used in the low vapour side of refrigeration system. The liquid refrigerant from the expansion valve enters in to the evaporator where it boils and changes in to vapour. The function of evaporator is absorbing heat from the surrounding location of medium which is cooled, by means of refrigerant. A simple refrigerant circuit is built up as shown in the sketch below. In what follows, the individual components are described to clarify a final overall picture[10]. A refrigerant in liquid form will absorb heat when it evaporates and it is this conditional change that produces cooling in a refrigerating process.

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Experimentation and Fabrication of Iceplant Using Ecofriendly Refrigerant

Experimentation and Fabrication of Iceplant Using Ecofriendly Refrigerant

Refrigeration is the process of removing heat from a body. The removed heat is moved to a place where it does not affect the working system. The main objective of refrigeration is to reduce heat to a lower temperature and maintaining it at that temperature. The term cooling refers generally to any natural or artificial process by which heat is dissipated. Ice manufacture is used for producing refrigeration effect to freeze potable water in can. Refrigeration is the process of maintaining a temperature of a system lower than the temperature of surrounding by continuous removal of heat. It work on the vapour compression refrigeration cycle. The main component of the system are compressor, condenser, evaporator, expansion valve, receiver.

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Increasing C O P Of A Refrigerator Using Diffuser

Increasing C O P Of A Refrigerator Using Diffuser

Thermostatic expansion valve or TEV is one of the most commonly used throttling devices in the refrigerator and air conditioning systems. The thermostatic expansion valve is the automatic valve that maintains proper flow of the refrigerant in the evaporator as per the load inside the evaporator. If the load inside the evaporator is higher it allows the increase in flow of the refrigerant and when the load reduces it allows the reduction in the flow of the refrigerant. This leads to highly efficient working of the compressor and the whole refrigeration and the air conditioning plant. The thermostatic expansion valve also prevents the flooding of the refrigerant to the compressor ensuring that the plant would run safely without any risk of breakage of the compressor due to compression of the liquid. The thermostatic expansion valve does not controls the temperature inside the evaporator and it does not vary the temperature inside the evaporator as its name may suggest. Beside the capillary tube, the thermostatic expansion valve is used widely in the refrigeration and air conditioning systems. While the capillary tube is used in the small domestic systems, the thermostatic expansion valve is used in the systems of higher capacities. It is commonly used in the industrial refrigeration plants, high capacity split air conditioners, packaged air conditioners, central air conditioners and many other systems.

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Surgical treatment of tricuspid regurgitation after mitral valve surgery: a retrospective study in China

Surgical treatment of tricuspid regurgitation after mitral valve surgery: a retrospective study in China

Most tricuspid valve replacements were performed due to the request of the patient and the surgeon ’ s pre- ference that also played a role since most of tricuspid valve replacement was performed by one surgeon (XRK) while others preferred tricuspid annuloplasty. Further, in our most recent practice, we (ZXL, XCL, WBJ, and GWH) prefer annuloplasty in the tricuspid position even in the second operation. This principle is actually more acceptable most recently [18]. As reported by Singh and colleagues, tricuspid valve repair is associated with better perioperative, midterm, and event-free survi- val than replacement in patients with organic tricuspid disease. We agree that repair should be performed whenever possible in patients with organic tricuspid dis- ease [18].

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Structural Design and FEM Analysis of Large Butterfly Valve

Structural Design and FEM Analysis of Large Butterfly Valve

ABSTRACT:Valves for hydro power projects are installed for safety, maintenance, and shut-off, as well as for flow and pressure regulation. A Butterfly valve is a type of flow control device, which is widely used to regulate a fluid flowing through a section of pipe. This type of valve is mainly used as safety valve, turbine inlet valve, and pump valve for low to medium design pressures. They are operated by oil hydraulic systems for opening and closing or by closing weight and hydraulic pressure for opening. For turbine inlet valves, oil pressure can also be taken from the governor hydraulic oil system. The sealing system is of flexible, adjustable rubber/metal type to reduce leakage to a minimum.Water flow through the valve is possible in both directions.The main objective of this thesis work is to analyses the option of fabricated variant for door & body in place of casted, reduction in the material of valve body & door by structural design & FEM analysis & optimization in the material of valve component.The 3D modeling to be performs for butterfly valve by using CAD software. Further the stress & displacement FEM analysis of the butterfly valve to be performed by using ANSYS tool to evaluate the optimized result.

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Optimization of automotive valve train components with implicit filtering

Optimization of automotive valve train components with implicit filtering

The different processors communicate through a master-slave arrangement. The master first sends modeling information to each of the processors and then waits. Each slave simulates the valve train at a particular engine speed and sends simulation data back to the master. If more simulations need to be done, the master sends the modeling information for those speeds to the slaves which have already returned their simulation data to the master. Once all the simulation data for every speed is received by the master, the master then evaluates the objective function for the system identification (3.9) or the cam optimization (3.10).

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Analysis of Performance Effect Factors of Three- Stage Electro-Hydraulic Servo Valve

Analysis of Performance Effect Factors of Three- Stage Electro-Hydraulic Servo Valve

forward in this paper to develop a nonlinear model for a higher performance three stage electro-hydraulic servo valve. The simulation results and experimental results on existing valve are consistent, which proves that the developed model is right. The analysis of the model shows that pilot valve bandwidth mainly affects the bandwidth of three-stage electro-hydraulic servo valve and is responsible for overshoot. The analysis also indicates that pilot valve resolution affects the resolution of three-stage electro- hydraulic servo valve and pilot valve rated flow affects the bandwidth and overshoot. The result further reveal that the position transducer affects the bandwidth and overshoot, servo controller affects the bandwidth and stability, the spool diameter and mass affect the bandwidth and hydraulic natural frequency, flow force on spool affects the bandwidth, overlap distance of restriction edge affects the dead zone size of mid-position and resolution of mid- position, coulomb friction force between spool and sleeve affects the resolution and radial clearance affects leakage flow and resolution. The analytical results are very useful because the methods can be applied to other similar systems.

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A comparison of wear behaviour of heat resistant steel engine valves and TiAl engine valves

A comparison of wear behaviour of heat resistant steel engine valves and TiAl engine valves

In the former work of Qu et al. [19, 20], the friction and wear characteristics of 23-8N steel (austenitic engine valve steel) and 42Cr9Si2 steel (martensitic engine valve steel) against 3Cr3Mo3W2V die steel were respectively investigated at high temperature. At the temperature range from 400 °C to 650 °C, the average COF of 23-8N steel on steady state varied in the range from 0.35 to 0.65 [19]. At the temperature range from 200 °C to 400 °C, the average COF of 42Cr9Si2 steel on steady state varied in the range from 0.4 to 0.7 [20]. As reported by Sun et al. [21], the COF of TiAl alloy against GH3128 nickel-based superalloy was about 0.27 and 0.36 at 800 °C with two sliding speeds. The wear test of TiAl alloy against Si3N4 at elevated temperatures is reported by Kang et al. [22]. At the temperatures from 25 °C to 900 °C, the COF of TiAl slightly decreased from 0.42 to 0.39. Although the material of matched specimens in the sliding wear tests were not real seat insert materials, the value of COF could be used. Consequently, the COF of the contact element in simulation set-up 2 was respectively set in the range from 0.1 up to 0.7 with 0.1 intervals. The simulation was carried out using ANSYS 14.0 software.

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The study of cardiac valve annular dimensions and their clinical significance

The study of cardiac valve annular dimensions and their clinical significance

The mitral vavlular complex comprises a) The mitral atrio-ventricular orifice and its valvular annulus b) leaflets, c) chordae tendinae and d) papillary muscles. The mitral annulus, in contrast to tricuspid, constitutes a relatively continuous ring of fibrous tissue. Although the entire annuluar circumference contacts the underlying left ventricular wall, the remaining 20% to 30% of the annulus is intracavitary and continuous with the aortic valve and the right and left fibrous trigones. Between the membranous septum and the cardiac crux, the mitral annulus becomes increasingly more posterior than the tricuspid annulus as the coronary sinus ostium and atrio ventricular septum intervene between the two valves.

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Transcatheter versus surgical aortic valve replacement: a systematic review and meta-analysis of randomised and non-randomised trials

Transcatheter versus surgical aortic valve replacement: a systematic review and meta-analysis of randomised and non-randomised trials

(PRISMA) guidelines where possible in performing our systematic review. 13 We performed a systematic search through MEDLINE (from 1950), PubMed (from 1946), EMBASE (from 1949), Current Contents Connect (from 1998), the Cochrane library, Google scholar, Science Direct and Web of Science until May 2014. The search terms included “ trans-catheter aortic valve implantation, percutaneous aortic valve implantation, percutaneous aortic valve replacement, transfemoral aortic valve implantation, transapical aortic valve implantation, trans- arterial aortic valve implantation, direct aortic valve implantation, transcatheter aortic-valve replacement (TAVR) ” , safety end points (stroke, myocardial infarction, atrial fi brillation, major vascular complications, acute kidney injury, blood transfusion), aortic valve stenosis (AS) AND “ surgical aortic valve replacement (SAVR) ” , which were searched as text word and as exploded medical subject headings where possible. No language restrictions were used in either the search or study selection. The ref- erence lists of relevant articles were also searched for appropriate studies. A search for unpublished literature was not performed. The search was conducted by two researchers (VN and JR).

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DESIGN AND ANALYSIS OF STORAGE PRESSURE VESSEL

DESIGN AND ANALYSIS OF STORAGE PRESSURE VESSEL

Meiqiu LI [1] has shown that Visual Design System Development of Wellhead‟s High Pressure Valve. The article introduces the advantages and the application of the visual design, analyzes the tendency and shortage of product development about high pressure valve used in wellhead. Combining the visual design method with collaborative design idea, a visual design system is designed for high pressure valve used in wellhead, which includes three modules. The development process and function of the system is described in detail. Based on a great deal database and modularized collaborative design, basic geometric design, three-dimensional Modeling, virtual assembly and finite element analysis (FEA) on chief parts are finished successfully. Practice indicated that the visual design system was an effective measure to improve efficiency of design, meet the demand of the development of product serialization, and reduce the cycle of development of product, reduce the cost. Geometric Design illustrates the function of the visual system. In general, it consists of four parts: Design Content: gate valve, check valve, relief valve, throttles valve and globe valve.

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Design Optimisation of Cam Shaft Angle Monitoring System For Industrial Improvements

Design Optimisation of Cam Shaft Angle Monitoring System For Industrial Improvements

The actual level of these stresses as compared to design or expected stress levels in their studied engine was unknown. Cams are designed to control the open and close intervals of the inlet and exhaust poppet valves. The radial cam used for this purpose consists of a circular disc having a semi- oval triangular protrusion. Rotation of the cam causes its profile to slide against the smooth flat closed end of a cylindrical shaft. The cam profile has a follower lift or valve opening side and a corresponding follower fall or valve closing side. Both the lift and fall sides of the profile can be divided in to three phases which are; the cam ramp, the cam flank and, the cam nose and measure the angle of cam shaft with 0.5mm precision level. Reference of given graph form computer, we can measure the Camshaft profile to obtain on line data logging system and also identify whether the casting dimension within the specification and Control the product quality. Data transmit from PC to Controller through CAN. For generation of cam shaft sensor signals, APU was used in this system instead of analog I/O channels. Analog output channels were used for simulation of other pressure and temperature sensor signals. Since the APU handles generation of the crank and cam shaft signals when the waveform is given, the CPU processing power can be used for running engine models or for other computational operations.

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Determination of mitral valve area with echocardiography, using intra-operative 3-dimensional versus intra- & post-operative pressure half-time technique in mitral valve repair surgery

Determination of mitral valve area with echocardiography, using intra-operative 3-dimensional versus intra- & post-operative pressure half-time technique in mitral valve repair surgery

MVA: Mitral valve area; TEE: Transoesophageal echocardiography; MVR: Mitral valve repair surgery; MV: Mitral valve; MS: Mitral valve stenosis; MR: Mitral valve insufficiency; 2D: 2-dimensional; PHT: Pressure half time; 3D: 3- dimensional; TTE: Transthoracic echocardiography; CPB: Cardiopulmonary bypass; MVA-PHT1: Mitral valve area measured as pressure half time technique with transoesophageal echocardiography; VTI: Velocity time integral; MVA-3D1: Mitral valve area measured as 3 dimensional planimetry technique; LA: Left atrium; LV: Left ventricle; AML: Anterior mitral leaflet; PML: Posterior mitral leaflet; MVA-PHT2: Mitral valve area measured as pressure half time technique with transoesophageal echocardiography by observer A; MVA-PHT3: Mitral valve area measured as pressure half time technique with transoesophageal echocardiography by observer B; MVA- 3D2: Mitral valve area measured as 3 dimensional planimetry technique by observer A; MVA-3D3: Mitral valve area measured as 3 dimensional planimetry technique by observer B; MVA-TTE: Mitral valve area measured as pressure half time technique with transthoracic echocardiography; SD: Standard deviation; ICC: Intraclass correlation coefficient; CI: Confidence interval; MDCT: Multi-detectors computed tomography.

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Experimental Analysis on the Effect of Condenser Diameter on the Performance of a Simple Vapor Compression Refrigeration System

Experimental Analysis on the Effect of Condenser Diameter on the Performance of a Simple Vapor Compression Refrigeration System

A simple vapour compression refrigeration system consists of mainly five components namely compressor, condenser, expansion device, evaporator and a filter/drier. The following study is focused towards finding out the effect of the condenser tube on the performance of the refrigeration system. A condenser tube is a small diameter tube which is used for the rejection of heat from refrigerant to surroundings to decrease the temperature of refrigerant or change of phase of the flowing fluid. The pressure difference between the entry and exit ends of the condenser tube is always equal to the discharge pressure of compressor. The diameter of the condenser tube used in the refrigeration appliances varies from 3mm to 4.5mm. The effect of the condenser tube as well as expander tube has been investigated by many researchers in the past and encouraging results were obtained.

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Combined Air Refrigeration, Air Conditioning and Water Dispenser Systems

Combined Air Refrigeration, Air Conditioning and Water Dispenser Systems

The three units are installed in a single unit and hence for effective working of these units, it is important some mechanism is used to be installed which would control the amount of the refrigerant into the system. For these purpose capillary tubes of different diameter are connected in diffuser valve. Thus, diffuser valve maintains the correct quantity of the refrigerant in three compartments.

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Investigation of droplet nucleation in CCS relevant systems – design and testing of the expansion chamber

Investigation of droplet nucleation in CCS relevant systems – design and testing of the expansion chamber

A droplet nucleation apparatus for CCS relevant systems is under construction in our laboratory. A newly designed expansion part of this apparatus was tested in this work. We used two arrangements for expansions in low and high pressure system using nitrogen as an expansion gas. The experiments showed that for the low- pressure system the expansion rate could be adjusted

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