초록 ▼

A heat pump apparatus includes a start assist valve for permitting refrigerant to flow from an outlet of a condenser to an inlet of an evaporator during start-up of the heat pump apparatus. The heat pump apparatus preferably includes an expansion orifice connected in fluid communication between the

A heat pump apparatus includes a start assist valve for permitting refrigerant to flow from an outlet of a condenser to an inlet of an evaporator during start-up of the heat pump apparatus. The heat pump apparatus preferably includes an expansion orifice connected in fluid communication between the outlet of the condenser and the inlet of the evaporator. The start assist valve provides a bypass for refrigerant flow around the expansion orifice during start-up of the heat pump apparatus. The apparatus also preferably includes a series of check valves cooperating with the start assist valve so that the start assist valve is operable only when the heat pump apparatus is in the cooling mode. The invention is particularly applicable to a direct expansion heat pump apparatus where one or more earth tap heat exchangers serve as the condenser when operating in the cooling mode. The apparatus preferably further includes a vapor refrigerant bleed connected in fluid communication with an expansion valve for bleeding vapor therefrom. The vapor bleeding causes the expansion valve to pass a greater amount of liquid refrigerant to thereby reduce liquid refrigerant in the condenser. Method aspects of the invention are also disclosed.

대표청구항 ▼

[ That which is claimed is:] [1.] A heat pump apparatus comprising:a condenser, an evaporator, and a compressor for circulating refrigerant through said condenser and said evaporator;expansion means connected in fluid communication between an outlet of said condenser and an inlet of said evaporator

[ That which is claimed is:] [1.] A heat pump apparatus comprising:a condenser, an evaporator, and a compressor for circulating refrigerant through said condenser and said evaporator;expansion means connected in fluid communication between an outlet of said condenser and an inlet of said evaporator for restricting liquid refrigerant flow from said condenser to said evaporator; andstart assist valve means movable between open and closed positions for permitting liquid refrigerant to flow from the outlet of said condenser to the inlet of said evaporator during start-up of the heat pump apparatus to thereby provide a bypass for liquid refrigerant flow around said expansion means during start-up of the heat pump apparatus.