For the same technical solution, if there is a physical product, it is recommended to apply for two patents: a utility model (to protect the product) and an invention patent (to protect the method).
Whether one can apply for two patents has nothing to do with the number of technical effects. The main reasons are that the protected objects are different (new methods cannot be protected) and the technical problems solved are different.
For example, if a technical solution can not only improve efficiency, but also save energy and protect the environment, you cannot apply for two patents separately, whether it is an invention or a new type.
In addition, if the focus of your protection is a technical solution, which means that such a solution should fall within the scope of your protection no matter what product it is applied to, then it is recommended that you give priority to applying for an invention;
If there are also physical products for sale, it is recommended that you also consider applying for a utility model.
In addition, when writing, be careful not to write the invention and new model as exactly the same technical solution. In this way, it is easy to be regarded as the same invention and creation. When the invention is authorized, the new model may become invalid.