Scroll kompresorių alyva

Scroll tipo šaldytuvų kompresorių alyvos

Rūšis

Klampumas prie 40ºC, mm2 /s

Tankis, prie 15ºC, kg/m3

Pliūpsnio temperatūra PMCC, ºC

Stingimo temperatūra ºC,

Panaudojimas, savybės

 

Nyco              

Nycobase 7450

 

 

 

22

 

 

 

997

 

 

 

258

 

 

 

-63

 

 

Sintetinė poliesterių pagrindo sroll refrižeratorinė alyva,

skirta naudojimui su bechloriais šaldymo agentais (HFC /  FKW), tokiais kaip R 134a, R 404A, R 407A, R 410A, R507, R 23 ir kt. plokščiasriegiams Scroll kompresoriams.

Atitinka :

Copeland Scroll alyva 22CC

Danfoss MLZ alyva

Daikin LXE alyva

Refra ZB, ZS, ZF alyvos

DIN 51503 KD specifikacijos alyva

 

Šaldymo alyvos parinkimas visų gamintojų Scroll kompresoriams

NYCOBASE 7450

Sintetinė POE šaldytuvų SCROLL kompresorių alyva

NYCOBASE - tai sintetinė tarpinės ISO VG 22-32  klasės šaldytuvų kompresorių alyva sudėtinių neopoliolio esterių pagrindu. Ši alyva specialiai sukurta naudojimui su R 134a ir kitais ekologiškai nekenksmingais aplinkai HFC šaldymo agentais.

Savybės

·      puikus terminis, oksidacinis ir cheminis stabilumas

·      labai geras abipusis tirpumas su R 134a ir kitais HFC tipo šaltnešiais žemose temperatūrose

·      puikus takumas ir aukštas klampumo indeksas mažina energijos sąnaudas žemoje temperatūroje

·      puikios tepimo savybės, stabdančios judančių detalių dėvėjimąsį

·      ilgas eksploatavimo laikotarpis, energotaupus efektyvumas

·      suderinamumas su elastomerais / sandarikliais, kartu naudojamais šaldymo sistemoje

·      Atitinka DIN 51503, Part 1standarto kategoriją KD

·      Keičia EAL Arctic 22CC ir atitinka Bitzer esterių alyvų 4.1 punktą (BSE 32 kategorija)

Panaudojimas

  • Alyva NYCOBASE rekomenduojama naudoti atviruose, pusiau atviruose ir hermetiškai užsandarintuose kompresoriuose, dirbančiuose su šaldymo agentais R 134a, R 404A, R 407A, R 410A, R507, R 23 ir kitais HFC šaldymo agentų mišiniais.
  • Alyva tinkama visiems šaldytuvų ir oro kondicionierių tipams: pramoniniai šaldytuvai, šaldymo sistemos maisto produktų sandėliuose, mobilūs transporto priemonių ir stacionarūs oro kondicionieriai, prekybinės maisto vitrinos.
  • Visų tipų stūmokliniams, plokščiasriegiams Scroll, diskiniams bei kitų konstrukcijų kompresoriams

Tipinės charakteristikos

Parametras

Vienetai

Tipinės vertės

Specifikacijos

       Metodas

 

-    Išvaizda prie 20°C

-

   skaidrus skystis

   skaidrus skystis

              -

-    Spalva

-

           < 0.5

           £ 0.5

ISO 2049

-    Tankis prie 20°C

kg/dm3

           0.997

              -

ISO 12185

-    Kinematinis klampumas prie

                                100°C

                                  40°C

mm2/s

 

6.2

            22.3

 

              -

       18.0 - 23.0

ISO 3104

-    Klampumo indeksas

-

            132

           >125

        ISO 2909

-    Stingio pradžios taškas

°C

            - 63

              -

        ISO 3016

-    Pliūpsnio taškas

°C

            258

              -

        ISO 2592

-   Rūgštingumas

mg KOH/g

0.01

# 0.05

ISO 6618

-   Hidroksilo kiekis

mg KOH/g

1

-

ASTM E 222 B

-    Vandens kiekis

mg/kg

             25

            £ 50

     MO-10-001 A

Duomenys yra tipiniai šiuo metu gaminamai produkcijai. Iki naujos produkcijos patvirtinimo Nyco specifikacijomis pasiliekama teisė keisti produkto charekteristikas.

Scroll komresoriaus alyvos tiekimas / Oil Supply System of a Scroll Compressor

After the oil flow reaches its steady state, the oil supply rates to bearings are larger for smaller viscosity value. These results qualitatively agree with the experimental results obtained by Cho et al. (2002) and Drost et al. (1992). Since their test data was obtained without an orbiting bearing, a direct or quantitative comparison is difficult. However, both tests and numerical data point to the same direction: the variation of the oil supply rate to bearing caused by the viscosity change is small compared to the magnitude of the oil flow rate. Conceptually, lower viscosity makes it easier for the oil to flow in the gallery and inside the bearings. This provides a physical ground for the results obtained. A lower viscosity also reduces the bearing dry time (Figure 7 and Figure 8). The magnitude of the dry time reduction is also in the same order as the total oil supply rate to the bearings. The features of the oil supply curves are similar for the upper main and orbiting bearings. The oil supply rates for the lower main bearing are different for two viscosity values. The oil supply rate for higher viscosity (26.4 centipoises) takes longer to reach its maximum value. The viscosity also changes the oil flow rate through the ports in the system. The oil flow rate through the port at the annulus below the lower main bearing shows different features. The higher viscosity value makes more oil pass through the port. This partially results from the lower flow rates through the bearings. The resistances through the bearings are high and the oil takes the least resistance route. The most noticeable feature of oil flow through the port is the periodic oscillation. This phenomenon is caused by the rotation of the feed holes. The magnitude of the oscillation is bigger for lower viscosity cases.

The oil flow inside the oil pump and sump is a complex physical process. When a scroll compressor starts, oil remains inside the sump. The bearings and pump are dry. As the motor rotates, the centrifugal force gradually overcomes gravity and surface tension. The pressure generated by the centrifugal force inside the flow field drives the oil into the oil gallery. The shape of the oil surface is determined by the balance of gravity, centrifugal force, and surface tension as well as gas flow above the oil surface. The rising oil level eventually reaches the bearings and ports. When the oil pressure overcomes the resistance of the bearings and ports, the oil starts flowing into bearings and ports in the system. The oil supply rates to bearings are resulted from design features and working conditions of oil pump and bearings. The design objective of the oil supply system is to provide sufficient oil to the bearings and minimize the bearing dry period.

The oil supply system is an integrated part of a scroll compressor. Figure 1(a) shows the schematic of a scroll compressor with the oil supply system. The oil supply system is located in the low-pressure side of the scroll compressor. Oil is pumped up from oil sump and feeds the lower main, upper main and orbiting bearings. There are a few ports connected to the oil gallery to send gas out and discharge the dirt in the system. Figure 1(b) shows the flow domain in the oil supply system. The lower main and orbiting bearings are end–port fed and the upper main bearing is side-port fed. The oil supply system includes three parts: oil sump, oil gallery, and bearings. The multiphase flow regime shows distinguishable features during the startup process in different parts of the system. The refrigerant gas-oil flow contains both continuous and dispersed gas and oil phases. To simulate this process, the flow inside the oil supply system is treated as a heterogeneous Eulerian-Eulerian multiphase flow. A commercial solver based on the finite volume method is used for this analysis. The oil in the shaft, including flows in the gallery and feed holes, is calculated in a rotating frame of reference. The oil sump is calculated in a stationary frame of reference. All the field quantities are obtained at each time step. The oil supply rates to bearings and ports are also calculated at each time step.

Scroll compressors for refrigeration

The compressor is the heart of every compression refrigeration circuit. It takes refrigerant in vapour form from a low pressure level (low-pressure suction side) to a high level (highpressure discharge side). There are several compressor types. For example, there are scroll compressors, screw compressors, rotary vane compressors, turbo compressors and reciprocating compressors. Today, we are focusing on scroll compressors for refrigeration applications. Scroll compressors are in widespread use in air-conditioning systems (their classic application is chiller). Scroll compressors are also gaining an increasing share of the market in the heat pump sector too. However, scroll compressors are highly suitable for refrigeration applications as well.

As the orbiting scroll orbits, centrifugal forces on the sides of the mating scrolls, along with some lubricating oil, form a seal that prevents gas pocket leakage. This is often referred to as “flank sealing,” a major contributor to the scroll’s high efficiency. A small amount of lubricating oil is usually entrained in the suction gases, and along with the centrifugal forces, provides the flank sealing. 
Tight up-and-down mating or sealing of each scroll’s tips prevents any compressed gas pocket leakage and adds to the efficiency. This up-and-down sealing is often referred to as “axial” sealing. Some scroll manufacturers use tip seals for the axial seal (Fig. 1). 

Scroll tip seals act the same as piston rings in a reciprocating piston-type compressor. These tip seals ride on the surface of the opposite scroll and provide a seal so gases cannot escape between mating scroll parts and the tips of the scrolls. 
The scroll compressor requires no valves, so it does not have valve losses that contribute to inefficiencies as piston-type compressors do. As mentioned earlier, the scroll compressor has no re-expansion of discharge gases, which can be trapped in a clearance volume and cause low volumetric efficiencies. This is why the scroll compressor has a very high capacity in high- compression ratio applications. 
A considerable distance separates the scroll compressor’s suction and discharge ports or locations. This greatly reduces the transfer of heat between the suction and discharge gases. Because of this, the suction gases will see less heat transferred into them and will have a higher density. This will increase the mass flow rate of refrigerant through the scroll compressor. 
Because of the scroll’s continuous compression process, and the fact that it has no valves to create valve noise, the scroll compressor produces very low gas-pulsation noises and very little vibration when compared to piston-type compressors. 
Finally, the scroll compressor’s simplicity requires only the stationary and the orbiting scroll to compress gas. Piston-type compressors require about 15 parts to do the same task.

In summary, the main reasons scroll compressors are gaining popularity over piston-type compressors in energy efficiency, reliability, and quieter operation are: 
• No volumetric losses through gas re-expansion as with piston-type compressors. 
• The scroll compressor requires no valves, so it does not have valve losses that contribute to inefficiencies as piston-type compressors do. 
• Separation of suction and discharge gases reduces heat transfer losses. 
• Centrifugal forces within the mating scrolls maintain nearly continuous compression and constant leak-free contact. 
• Radial movement eliminates high-stress situations and allows for just the right amount of contact force between mating scroll surfaces. This action allows the compressor to handle some liquid. 
• Scroll compressors have a continuous compression process and have no valves to create valve noise. This creates very low gas-pulsation noises and very little vibration when compared to piston-type compressors.