if (File.Exists(Util.XLSXFileName))
{
File.Delete(Util.XLSXFileName);
}
Workbook workbook = new Workbook();
workbook.LoadFromFile(Util.CSVFileName, ",", 1, 1);
Worksheet sheet = workbook.Worksheets[0];
sheet.Name = "csv to excel";
workbook.SaveToFile(Util.XLSXFileName, ExcelVersion.Version2010);
var workbookFileInfo = new FileInfo(Util.XLSXFileName);
using (var excelPackage = new ExcelPackage(workbookFileInfo))
{
var worksheet = excelPackage.Workbook.Worksheets.SingleOrDefault(x => x.Name == "Evaluation Warning");
excelPackage.Workbook.Worksheets.Delete(worksheet);
excelPackage.Save();
}