How much will it be from the chang an grand hotel beijing to the cruise port of xingang

Do you mean the taxi fare from your hotel to the cruise port of Xingang?
I think the cruise port of Xingang is the one in Tianjin, right? If so, the direct taxi not suggested, because it will be so high. Generally speaking, if you take the taxi to reach Tianjin city downtown, the fare is around 300 to 400RMB.
It is suggested to take the intercity train to reach Tianjin Railway Station from BJ South Railway Station and then change to local light rail to reach Citizen Square Station. Then you can take a taxi to reach the port.
The subway fare from your hotel to south railway station is about 2RMB. The intercity train ticket costs 55RMB for second class seat and 66RMB for the first seat. The light rail in Tianjin cost about 9RMB and then the taxi fare from Citizen Square to your port is around 25 to 30RMB.

Thank you Katie for taking the time to answer my worries. There are three of us travelling and the transfers if bought with the cruise were very expensive. Thanks Dee