A 1-m3 rigid tank contains 100 kg R-22 at ambient temperature, 15C. A valve on top of the tank is opened, and saturated vapor is throttled to ambient pressure, 100 kPa, and flows to a collector system. During the process the temperature inside the tank remains at 15C. The valve is closed when no more liquid remains inside. Calculate the heat transfer to the tank and total entropy generation in the process.