Method to charge multiple refrigerants with desired concentrations

A charging method comprising:

• receiving a first refrigerant in vapor form via a first inlet of a charging device;
• receiving the first refrigerant in liquid form via a second inlet of the charging device;
• receiving a second refrigerant in liquid form via a third inlet of the charging device,
• wherein the second refrigerant is a different type of refrigerant than the first refrigerant;
• outputting the first and second refrigerants from an outlet of the charging device to a refrigeration system;
• and
• selectively opening first, second, and third valves and charging the refrigeration system with target amounts of the first and second refrigerants, respectively,
• wherein:
• the first valve is fluidly connected between the first inlet and the outlet;
• the second valve is fluidly connected between the second inlet and the outlet;
• the third valve is fluidly connected between the third inlet and the outlet;
• selectively opening the first, second and third valves includes, before opening the second and third valves, opening the first valve and outputting the first refrigerant in vapor form to the refrigeration system;
• and
• selectively opening the first, second, and third valves includes, after a pressure of the refrigerant within the refrigeration system is greater than a predetermined pressure, closing the first valve and selectively opening the second and third valves.

A charging device comprising:

• a first inlet configured to receive a first refrigerant in vapor form;
• a second inlet configured to receive the first refrigerant in liquid form;
• a third inlet configured to receive a second refrigerant in liquid form,
• wherein the second refrigerant is a different type of refrigerant than the first refrigerant;
• an outlet configured to output the first and second refrigerants to a refrigeration system;
• a first valve fluidly connected between the first inlet and the outlet;
• a second valve fluidly connected between the second inlet and the outlet;
• a third valve fluidly connected between the third inlet and the outlet;
• a control module configured to selectively open the first, second, and third valves and charge the refrigeration system with target amounts of the first and second refrigerants, respectively,
• wherein the control module is configured to, before opening the second and third valves, open the first valve and output the first refrigerant in vapor form to the refrigeration system,
• wherein the control module is configured to open the first valve and output the first refrigerant in vapor form to the refrigeration system until a pressure of refrigerant within the refrigeration system is greater than a predetermined pressure,
• wherein the control module is configured to, after the pressure of the refrigerant within the refrigeration system is greater than the predetermined pressure, close the first valve and selectively open the second and third valves;
• and
• a pump fluidly connected between the third valve and the outlet and configured to pump the second refrigerant to the outlet,
• wherein the control module is configured to operate the pump when the third valve is open, and
• wherein the control module is configured to operate the pump based on a target concentration of the second refrigerant, a predetermined density of the second refrigerant, and a mass flowrate of the first refrigerant.