Method for increasing the valve capacity of a refrigeration unit

摘要

A system supplies a fluid to an evaporator of a refrigeration unit and has first and second lines connected to a fluid inlet of the evaporator. The system has an expansion valve with a continuously modifiable first flow cross section, disposed in the first line, the continuously modifiable first flow cross section setting a first mass flow through the first line. A shut-off device is disposed in the second line and switchable discretely between an open position and a closed position. A throttle with a constant second flow cross section is disposed in the second line. A control unit continuously modifies the first flow cross section of the expansion valve and controls the shut-off device as a function of the first flow cross section.

主权项

1. A system for supplying a fluid to an evaporator of a refrigeration device, the system comprising:
a first line connected to a fluid inlet of the evaporator; a second line connected to the fluid inlet of the evaporator; an expansion valve with a continuously variable first flow cross section, wherein the expansion valve is positioned in the first line in such a manner that the continuously variable first flow cross section sets a first mass flow of the fluid through the first line; a shut-off device positioned in the second line, the shut-off device being discretely switchable between an open position and a closed position such that a second mass flow of the fluid is conveyed through the second line when the shut-off device is in the open position and a fluid flow through the second line is prevented when the shut-off device is in the closed position; a throttle with a constant second flow cross section, the throttle being positioned in the second line in such a manner that the second mass flow is conveyed through the second flow cross section when the shut-off device is in the open position; and a control unit to control the expansion valve and set the continuously variable first flow cross section, and to control the shut-off device as a function of the continuously variable first flow cross section defined by the expansion valve, to thereby control a total mass flow including the first mass flow through the first line and a second mass flow through the second line, wherein controlling the total mass flow includes: increasing the total mass flow above a threshold mass flow by: switching the shut-off device from the closed position to the open position, to thereby allow the second mass flow of the fluid through the second line, and controlling the expansion valve to reduce the first mass flow of the fluid through the first line.