public ActionResult FuelParameters(FuelParametersView model)
        {
            if (ModelState.IsValid)
            {
                var variant = db.Variants.Find(model.Id);
                if (variant == null)
                {
                    return(HttpNotFound());
                }

                if (variant.InputData == null)
                {
                    variant.InputData = new InputData();
                }

                variant.InputData.Id          = model.Id;
                variant.InputData.HeatBlast   = model.HeatBlast.Value;
                variant.InputData.HeatFull    = model.HeatFull.Value;
                variant.InputData.HeatNatural = model.HeatNatural.Value;
                variant.IsFuelParametersExist = true;

                if (variant.ResultData != null)
                {
                    Session["old_result"] = ResultView.CopyFrom(variant.ResultData);
                }

                try
                {
                    Calculate(variant);
                }
                catch (Exception exc)
                {
                    ModelState.AddModelError("", "Не удалось выполнить расчет");
                    ModelState.AddModelError("", exc.Message);
                    return(View(model));
                }

                db.SaveChanges();
                return(RedirectToAction("Results", new { id = model.Id, checkOldResults = true }));
            }

            return(View(model));
        }