GB/T 38274-2019Lubrication systems - Efficiency assessment method (English PDF)

3.1 Test preparation and general test conditions

3.1.1 Develop a test outline.

3.1.2 The test equipment should be checked for correctness and functional suitability before the test. Period.

3.1.3 Check the valve and control system of the system under test to eliminate factors that affect normal testing.

3.1.4 Power supply. voltage fluctuation ± 5%, frequency fluctuation ± 1%.

3.1.5 The kinematic viscosity of the test lubricating oil is 288mm2/s ~ 352mm2/s (at the temperature of 40 °C).

3.1.6 The solid particle pollution level of the test oil shall meet the requirements of-/ 20/17 ~-// 21/18 in Table 1 of GB/T 14039-2002.

3.2 Lubrication pump test conditions

3.2.1 During the test, the oil temperature shall be 40 ° C ± 3 ° C.

3.2.2 Use the torque and speed sensor to detect the torque and speed of the input end of the tested lubrication pump. Torque and speed sensors are installed horizontally, using When the rigid coupling is used, the coaxiality of the pump device must be less than 0.05mm; when the flexible coupling is installed, the coaxiality of the pump device must be less than 0.05mm. 0.2mm. The installation diagram of the torque speed sensor is shown in Figure 1. Figure

3.3 Cooler test conditions

3.3.1 The inlet temperature of the cooling medium (cooling water) of the cooler is 28 °C ± 2 °C.

3.3.2 The flow rate of the cooling medium (cooling water) of the cooler is

1.5 times the flow rate of the cooling medium (lubricating oil).

3.3.3 The relative error of heat balance should be less than 5%. The calculation of the relative error of the heat balance is shown in equation (8).

3.4 Electric heater test conditions

3.4.1 The volume of the test fuel tank is 1.2m3, and the lubricating oil inside the tank is 1m3.

3.4.2 The lubricating oil is heated from an initial temperature of 10 ° C ± 2 ° C to 25 ° C ± 2 ° C.

3.4.3 The ratio of the electric energy loss of the electric heater to the total electric energy should be less than 5%. The calculation is shown in equation (15).

3.5 Measurement accuracy The allowable error of measuring instruments and meters should be within the range specified in Table 1. Table

1 Allowable errors of measuring instruments and meters Measurement category unit instrument, meter reading accuracy Temperature °C ± 1.0% Pressure MPa ± 1.6% Flow L/min ± 1.5% Torque N · m ± 1.0% Speed r/min ± 1.0%

4.3 Lubrication pump energy efficiency assessment method

4.3.1 Instructions for energy efficiency assessment of lubrication pumps The energy efficiency evaluation of the lubrication pump is described as follows:

a) Test the volumetric efficiency and mechanical efficiency of the lubrication pump under the set conditions, and calculate the total efficiency of the lubrication pump. The total efficiency of the lubrication pump The value is used as the energy efficiency evaluation value of the lubrication pump.

b) Refer to Appendix A for the schematic diagram of the lubrication pump energy efficiency test, and refer to Appendix B for the schematic diagram of the lubrication pump energy efficiency test.

4.3.2 Test methods and calculations

4.3.2.1 Treat the flow of the lubrication pump at zero pressure difference as the theoretical flow. Start the tested lubrication pump and adjust the outlet pressure of the lubrication pump. When the outlet pressure is approximately zero (<=0.05MPa), record the flow rate of the pump at this time, and record the flow rate of the lubrication pump at zero pressure difference as Q0.

4.3.2.2 Calibrate and adjust the outlet pressure of the lubrication pump to the maximum working pressure of the lubrication system. Q, the speed of the pump is recorded as n, and the torque of the pump is recorded as T.

4.3.2.3 The principle of performing three measurements on each parameter and taking the average value to participate in the calculation.

4.3.2.4 The ratio of the actual output power of the lubrication pump after the volume loss to the theoretical output power of the lubrication pump is called the volumetric efficiency. The method is shown in formula (2). etav = QDeltap Q0Deltap × 100% = Q0 × 100% (2) Where. etav

--- volumetric efficiency of the lubrication pump,%; Q

--- the actual flow of the pump, the unit is liters per minute (L/min); Deltap

--- the differential pressure between the inlet and outlet of the lubrication pump, in megapascals (MPa); Q0

--- The flow rate of the lubrication pump at zero pressure difference, the unit is liters per minute (L/min).

4.3.2.5 The actual input power Pr of the lubrication pump is calculated as shown in equation (3). Pr = n × T (3) Where. Pr

--- the actual input power of the lubrication pump, in kilowatts (kW); n

--- the speed of the lubrication pump in revolutions per minute (r/min); T

--- the torque of the lubrication pump, the unit is Nm (N · m).

4.3.2.6 The ratio of the theoretical output power of the lubrication pump to its actual input power is called the mechanical efficiency of the lubrication pump. The calculation method is shown in equation (4). etam = Q0 × Deltap Pr × 100% (4) Where. etam

--- mechanical efficiency of the lubrication pump,%.

4.4 Evaluation method of energy efficiency of cooler

4.4.1 Energy efficiency assessment instructions for coolers Description of cooler energy efficiency assessment.

a) Lubrication system cooler usually adopts non-phase change, counter-flow type partition wall cooler. Lubrication system cooler energy efficiency assessment applies to Non-phase change, counter-flow type inter-wall cooler.

b) The energy efficiency of the cooler is evaluated by its heat exchange efficiency, and the value of the heat exchanger efficiency of the cooler is used as the energy efficiency evaluation value of the cooler.

c) Refer to Appendix C for the energy efficiency test schematic diagram of the cooler, and refer to Appendix D for the energy efficiency test installation diagram of the cooler.

4.4.2 Test methods and calculations

4.4.2.1 Calculation of exothermic heat of lubricating oil and endothermic heat of cooling water.

a) The exothermic heat of lubricating oil is calculated according to formula (6). Q1 = qm1c1 (t'1-t " 1) = W1 (t'1-t " 1) (6) Where. Q1

--- exothermic heat of lubricating oil, unit is watt (W); qm1

--- mass flow of lubricating oil, unit is kilogram per second (kg/s); c1

--- Constant pressure specific heat capacity of lubricating oil, unit is joule per kilogram Celsius [J/(kg · °C)]; t'1

--- lubricating oil inlet temperature, unit is Celsius (° C); t " 1

--- temperature of lubricating oil output, in degrees Celsius (° C); W1

--- The thermal capacity of lubricating oil, in watts per degree Celsius (W/°C).

b) The heat absorbed by the cooling water is calculated according to formula (7). Q2 = qm2c2 (t " 2-t'2) = W2 (t " 2-t'2) (7) Where. Q2

--- heat absorption heat of cooling water, unit is watt (W); qm2

--- mass flow of cooling water, unit is kilogram per second (kg/s); c2

--- specific heat capacity of constant pressure of cooling water, unit is joule per kilogram Celsius [J/(kg · °C)]; t'2

--- cooling water inlet temperature, unit is Celsius (° C); t " 2

--- cooling water outlet temperature, unit is degrees Celsius (°C); W2

4.5 Evaluation method of energy efficiency of electric heater

4.5.1 Evaluation of energy efficiency of electric heaters The energy efficiency evaluation of electric heaters is described as follows:

a) The energy efficiency of electric heaters is evaluated by the heating efficiency of electric heaters. The heating efficiency value of electric heaters is used as the energy efficiency of electric heaters. Evaluation value

b) Refer to Appendix E for the schematic diagram of the energy efficiency test installation of electric heaters.

4.5.2 Test methods and calculations

4.5.2.1 Measure the temperature rise of heating oil of electric heater. The temperature rise of heating oil of electric heater For the temperature measuring element, the distance between the three temperature measuring elements and the electric heater is 100mm, and the average of the three measurements is taken.

4.5.2.2 The measurement of heating time shall comply with the requirements of 3.4.2, measuring the heating time T when the electric heater heats the lubricating oil to 25 ° C.

4.5.2.3 The method for calculating the power of electric heaters is as follows:

a) Use a multimeter to measure the resistance of the electric heater.

b) Use a multimeter to measure the voltage of the electric heater during operation.

c) Calculate the power of the electric heater, see equation (13). P = U2 1000R (13) Where. P

--- the power of the electric heater in kilowatts (kW); U

--- the voltage when the electric heater works, the unit is volt (V); R

--- the resistance of the electric heater, the unit is Europe (Omega).

d) Calculate the heat dissipation power of the fuel tank according to formula (14). Pd = kADeltat (14) Where. Pd

--- the cooling power of the fuel tank, in kilowatts (kW); k

--- coefficient of heat dissipation in watts per square meter Celsius [W/(m2 · °C)]; A

--- The heat radiation area of the fuel tank, the unit is square meter (m2); Deltat

--- The temperature rise of the lubricating oil, the unit is Celsius (°C).