Ejector and refrigerating system

An ejector for use in a refrigeration system, comprising:

• a mixing chamber comprising a mixed fluid outlet;
• a high-pressure fluid passage extending from a high-pressure fluid inlet to the mixing chamber, a flow valve for controlling a flow rate being disposed in the high-pressure fluid passage;
• a suction fluid passage extending from a suction fluid inlet to the mixing chamber;
• a thermal bulb disposed upstream of the flow valve, in the high-pressure fluid passage or outside the high-pressure fluid passage;
• and an elastic diaphragm disposed in the high-pressure fluid passage, wherein a closed cavity is on a first side of the elastic diaphragm, and the high-pressure fluid passage is on a second side of the elastic diaphragm;
• the thermal bulb is in communication with the closed cavity, and the thermal bulb and the closed cavity are filled with fluid;
• and the elastic diaphragm is associated with the flow valve so that an opening degree of the flow valve varies in response to a change in a pressure difference across two sides of the elastic diaphragm;
• wherein the elastic diaphragm is associated with the flow valve such that when a pressure of the high-pressure fluid is lower than a desired pressure, the opening degree of the flow valve will decrease, thereby increasing the pressure of the high-pressure fluid;
• and when the pressure of the high-pressure fluid is higher than the desired pressure, a pressure of the fluid in the closed cavity is lower than that of the high-pressure fluid, and the opening degree of the flow valve will increase, thereby decreasing the pressure of the high-pressure fluid.