Remote Sensing Bulb Location

After the surface is properly prepared, it is painted aluminum paint to minimize future corrosion. The clamp and screws nonferrous metals to prevent corrosion. Sensitive lamp must be located within the refrigeration space so diat it can accurately measure die of overheating. Suction line less than% (2.2 cm) outer diameter (OD), sensing bulb mounted on top of the line. Suction line, more than% (2.2 cm) OD sensing lamp is located on the 4 or 8 hours. In this position provides a more efficient control over the expansion valve. The bulb is not tied down to the bottom of the tube, because oil or liquid, which is deposited at the bottom of the die tube will prevent accurate measure of overheating.

Sensitive lamp must be located so that it is not influenced temperatures other than the suction line temperature, especially during compressors outside the loop. If the die temperature of the bulb for out-of-cycle allowed to rise significantly higher than in the evaporator, the valve will open. Therefore, the evaporator is filled with liquid refrigerant diat will flood back into the compressor when it starts. When the light is inside the refrigerated space, the difference in temperature between valve and the evaporator is usually not large enough to affect the expansion valve operation. Conversely, when the remote sensing of the ball is out of the cooled space, light and suction line should be well isolated from the environment. Insulation should be nonliygroscopic (water absorption) and shall extend at least 1 ft (30.5 cm) above the two ends of the sensing bulb.

Care must be taken to find the sensing bulb at least 1.5 metres (46 cm) from the point where the bare suction line leaves the refrigerated space. This strategy reduces the likelihood that carefully enumerates the lamp due to the heat. If this situation occurs, TXV will open allowing the fluid to fill the evaporator during the die-off cycle. Every time when the ball is in such a condition that the possibility exists that can open the valve on the die cycle, the solenoid valve should be installed in the liquid line near the expansion valve and the system will work widi a pump-down cycle. This ensures positive disable flow of fluid during the die-off cycle.

Care should be taken to organize the suction pipe so that oil and liquid will flow by gravity from sensing the location of the bulbs in the direction of the compressor. If the suction line of the sensing bulb location must be caught or partially trapped, TXV's performance will decline. In these situations sensing lamp must be installed correctly. These installation strategies to prevent oil or fluid from collecting in the location of the sensors and affecting the operation of the expansion valve. This pipeline agreements frequently used in large plants to minimize the possibility of ingress of liquid refrigerant in the compressor. Depicts an installation in which the fluid can accumulate in the suction traps, located at the outlet of the evaporator. When diis happens, TXV hunts, as a trap alternately fills and empties. TXV operations under this condition may become irregular, so that the liquid can be fed back into the compressor steam pressure that builds up in the evaporator above trap. This bullet can lead to severe damage of the compressor.

In conditions when there is poor air circulation through the evaporator, the refrigerant liquid can pass through some schemes without boiling and, consequently, without affecting the sensing bulb. This condition may cause flooding back to die compressor. Correct sensing bulb location is shown by the dashed line. However, changing sensing location of the bulbs in the application will not improve the evaporators efficiency, if there is poor air distribution. This is only to minimize the possibility of flooding back to compressor. To maximize system capacity and efficiency of air distribution problem should be solved.

Search sensing bulb on a vertical section of the suction line must be avoided whenever possible. However, if no other, perhaps, the lamp should be installed above the liquid trap on the suction line of the circuit. In some cases, it may be necessary or desirable to use the pipelines wells home sensing bulb. This design places the light within the suction line. As a rule, pipes are also used whenever low superheats are employea or sensing bulb was probably under the influence of heat conducted througli suction line with warm place. This capillary tube to act as a measuring device while maintaining the operating pressure differential between the high and low pressure sides of the system.

Resistance to the flow of the refrigerant, produced capillary, depends on the length of the barrel and pressure difference through its ports. There is a direct relationship between the size of the cylinder and the differential pressure between condenser and evaporator, while the inverse relationship that exists between the die refrigerant mass flow and length of the tube. The cap of the tube for the selected application based on the saturation pressure in the condenser and evaporator along widi flow of the liquid refrigerant is necessary to meet the requirements of the system during operation...