An experiment was conducted to analyze a tubular heat exchanger's turbulent heat transfer characteristics. The heat ex-changer was equipped with a newly designed perforated (rectangular) conical baffle plate consisting of two rectangular opposite-oriented flow deflectors with adjustable tilt angles. The baffle plate was installed at the entrance of the heat ex-changer, resulting in a counter-swirling flow pattern downstream. Three baffle plates were installed along the flow direction with different pitch ratios (spacing between baffle plates divided by the diameter of the heat exchanger). The experiment examined the effects of pitch ratio (ranging from 0.6 to 1.2), deflector tilt angle (ranging from 30° to 50°) and Reynolds numbers (ranging from 16 500 to 30 000) on the heat transfer performance. The results showed that the pitch ratio and tilt angle significantly affected the performance of the heat exchanger. In particular, a configuration with a tilt angle of 30° and a pitch ratio of 1 resulted in an average improvement of 26.9% in the heat exchanger's performance compared to a heat exchanger without a conical baffle plate under similar operating conditions.