PMC

Effects of engine load on (a) engine load on O₂ emissions, (b) engine speed on O₂ emissions, (c) engine load on CO₂ emissions, (d) engine speed on CO₂ emissions, (e) engine load on CO emissions, (f) engine speed on CO emissions, (g) engine load on NO emissions, (h) engine speed on NO emissions, (i) engine load on SO₂ emissions and (j) engine speed on SO₂ emissions.

Effects of engine load on (a) engine speed, (b) PTO torque, (c) PTO speed on PTO torque, (d) engine load on brake power, (e) engine speed on brake power, (f) engine load on fuel consumption, (g) engine speed on fuel consumption, (h) engine load on (BSFC). (i) engine speed on (BSFC), (j) engine load on BMEP, (k) engine speed on BMEP, (l) engine speed on BTE and (m) engine load on BTE.

Engine was operated at four steady-state modes. One of the selected modes at each of the engine speeds represented heavy engine load (M2 and M4 with an engine speed of 2950 rpm and 2100 rpm, torque of 108.4 Nm and 138 Nm, and power 34.3 kW and 30.6 kW, respectively), while the other was more representative of light engine load (M1 and M3 with an engine speed of 2950 rpm and 2100 rpm, torque of 63.7 Nm and 73.2 Nm, and power 17.2 kW and 14.9 kW, respectively).

a The most probable power P^* with τ. Black circles represent P^* for the Gaussian engine, blue triangles represent P^* for the non-Gaussian engine with κ = 10 at the hot reservoir and red squares represent P^* for the non-Gaussian engine with κ = 20 at the hot reservoir. With decreasing τ, P^* increases considerably (inset) for the non-Gaussian engine with κ = 10 at the hot reservoir and rapidly falls off for τ ≤ 8 s. For the non-Gaussian engine with κ = 20 at the hot reservoir, the increase in P^* is rather small and it decays for τ ≤ 10.6 s. The blue and red solid lines are calculated from the fit to Eq. () and are overlaid on the experimental data. The blue (red) vertical dashed line indicates the τ below which P^* is negative for the non-Gaussian engine with κ = 10 (κ = 20) at the hot reservoir. b The most-probable efficiency ε^* for various τ. Black circles represent ε^* for the Gaussian engine, blue triangles represent ε^* for the non-Gaussian engine with κ = 10 at the hot reservoir and red squares represent ε^* for the non-Gaussian engine with κ = 20 at the hot reservoir. The blue solid lines indicate the theoretically calculated Stirling saturation, ε_Sat. Efficiency just before the rapid drop in power at τ = 8 s (τ = 10.6 s) of the non-Gaussian engine with κ = 10 (κ = 20) at the hot reservoir agrees with the Curzon–Ahlborn efficiency ε_CA. The error bars indicate the standard deviations of the mean and the most probable quantities across different experiments. Note that the black vertical line through the first data point (smallest τ) is a portion of a large error bar. The error bars at other τ values are smaller than the symbol size.