**5. Estimating the indicators of optimum temperature (OT) of the engine and the vehicle under operating conditions**

= 20 (0/−20)°C. These options are characterized by the operation of phase-transitional TA and the rapid heating of the engine subsystem at the same time. For relevant temperatures of *Тamb*. = 20 (0/−20)°C, the duration of heating is reduced according to the values 14.4 (24/33.3) min for the coolant and 14.2 (25/35) min for motor oil. This option is compared with the standard systems of the engine (option 1), i.e., 22.8 (31/47.5) min for the coolant and 24.2 (33.3/50.5) min for motor oil. Thus, the duration of heating is reduced by 8.4 (7.1/14.2) min or by 36.9 (22.9/29.9)%

The indicators of the ICE thermal state during rapid after-start heating of the coolant and motor oil of the engine with the combined heating system were compared with the standard systems of the engine (option 1, **Table 1**) from 50 to 85°С, min (**Figure 5**). The greatest reduction in the heating time was obtained in options 3, 7–11, 14–19 for ambient temperatures at

The duration of maintaining the engine *Т*<sup>c</sup> ≈ 50°С and *Т*МО ≈ 50°С, min (**Figure 6**) within the combined heating system (option 1, **Table 1**) was compared with the standard systems. A substantial increase in long-duration stop of the engine with the combined heating system when the engine was not running in an idling mode was obtained. The duration of maintenance did not change in option 2 for the coolant and motor oil, in options 5 and 6 for the coolant, in options 12 and 13 for motor oil. According to **Figure 6**, the increase in the maintenance duration occurred in options 3–18 for both the coolant and for motor oil for ambient temperatures

 = 20 (0/−20)°C. The most significant increase in duration occurred in option 19 for the coolant and motor oil, in options 15 and 17 for the coolant, in options 9 and 11 for motor oil respectively. These options are characterized by simultaneous operation of phase-transitional TA and the rapid heating of the engine subsystem, contact thermal accumulator subsystem as well as thermal accumulator for storing motor oil and thermal accumulator for storing a coolant previously heated to *Т*HAМ *=* 85°С. The duration of maintaining *Т*<sup>c</sup> ≈ 50°С and *Т*МО ≈ 50°С is increased according to the values from 720 (600/510) min to 2410 (2078/1870) min for the coolant and from 720 (600/510) min to 2410 (2078/1870) min for motor oil. This option was compared with the standard systems of the engine (option 1), i.e., 80 (40/20) min for the coolant and 100 (60/30) min for motor oil. Thus, the duration of maintaining the temperatures is increased from 640 (560/490) min. to 2330 (2038/1850) min or ranging from 9 (14/24) to 29.13 (50.95/92.50) times for the coolant and from 620 (540/480) min to 2310 (2018/1840) min or ranging from 6.2

(9/16) to 15.9 (33.63/61.33) times for motor oil for appropriate operating conditions.

needs, climatic conditions and the category of the vehicle.

The use of the combined heating system is generally effective (**Figures 4**–**6**) for pre-start and after-start thermal development of the vehicular engine and for maintaining it for a long time when it is not running under different climatic conditions. The peculiarities of the combined heating system components and the technology for use are chosen depending on operational

 = 20(0/−20)°C. These options are characterized by the operation of phase-transitional TA and the rapid heating of the engine subsystem at the same time. The duration of heating is reduced according to the values 9.7 (19.2/26.2) min for the coolant and 10.5 (21.2/28.2) min for motor oil. This option is compared with the standard systems of the engine (option 1), i.e., 22.8 (31/47.5) min for the coolant and 24.2 (33.3/50.5) min for motor oil. Thus, the duration of heating is reduced by 13.1 (11.8/21.3) min or by 57.5 (38/44.8)% for the coolant and by 13.7

for the coolant and by 10 (8.3/15.5) min or by 41.3 (25/30.8) % for motor oil.

(12.1/22.3) min or by 57 (36/44.2)% for motor oil.

*Тamb*.

116 HVAC System

*Тamb*.

The estimation was based on the mathematical modeling of the "combined heating of the engine and the vehicle" system. The mathematical modeling was carried out for various components of the CHS used for the truck and a car. The options of operating conditions and methods of the engine and the vehicle heating were chosen in accordance with the provisions of [1, 5, 10, 11, 16–19].

The influence of various components of the CHS on pre-start heating of the engine was analyzed in terms of fuel consumption (kg/h). The results revealed the most significant components of the CHS, namely in options 2 and 3. For them, additional estimation studies were carried out to determine the specific indicators of the total influence of the CHS components on the coolant and MO heating time from *Т*amb. to 50°C and from 50 to 85°C. All indicators were compared with thermal development indicators of the engine standard systems. **Figure 7(a)** shows the main indicators of the truck engine thermal development when heating the coolant and MO from *Т*amb. to 50°C. The most significant components of the CHS were studied. They have the greatest influence on thermal processes in the engine coolant and MO. Thus, a phase-transitional TA has the greatest influence on the parameters of the engine coolant heating for all ambient temperatures +20 (0/−20°С) − 0.085 (0.134/0.168) kg/h; and for MO heating, respectively 0.085 (0.133/0.167) kg/h.

To estimate the total influence of the CHS components on the coolant and MO heating time, the most significant components were chosen, namely in options 3–6, 12, 13 and 19 (**Figure 7(b)**. All indicators were compared with the indicators of the engine standard systems. The total influence on thermal development processes implies the total time of pre-start (from *Т*amb. to 50°C) and after-start heating (from 50 to 85°C) and the time of maintaining the coolant and MO temperature within ≈50°C in relation to the fuel consumed for thermal development. **Figure 7b** shows the main study results of the influence of the CHS components on the total time of the coolant and MO thermal development. It is determined in the specific indicators of fuel consumption, kg/h. The lowest fuel consumption indicators were obtained for the CHS with such components: TA + CTA + TASMO (ТHАМ = 85°С) + ТАSC (ТHАМ = 85°С). Phasetransitional TA indicators are worth mentioning as well. They are optimal for all options of the heating, both according to the options of the heating and the ambient temperatures.

In general, to provide the OT of the engine with the CHS, it is advisable to use all options of simultaneous influence on the coolant and MO.

To provide the temperature influence on the CC of the EGCS indicators, it is advisable to use TA installed in the exhaust system of the engine. When using TAEGCS, depending on the option of the engine heating, the time of reaching the temperature at the Light-off point (250°С/523 K) of the CC heating curve is 3–5 min of the CC operation for all options. This indicator is almost twice as good as the experimentally obtained indicators of the CC heating.

To ensure the compliance with the requirements for the heating periods of different areas of the vehicle interior and the driver, the use of the CHS is completely stipulated. In this case,

combined heating system on thermal development indicators of the engine and the vehicle were obtained. The use of the combined heating system in the vehicular engine for different ambient temperatures enables to improve the indicators of the duration of coolant and motor oil thermal development. It is possible at: pre-start and after-start heating by 22.9–57.5% and 25–57%, and for a long storage ranging from 9 to 92 times and from 6.2 to 61 times, without the engine operation in an idling mode. The use of the combined heating system is generally effective for pre-start and after-start thermal development of the vehicular engine and for maintaining it for a long time when it is not running under different climatic conditions. The peculiarities of the combined heating system components and the technology for use are chosen depending on operational needs, climatic conditions and the category of the vehicle. Thus, in order to ensure safety in terms of maintaining the OT of the engine and the vehicle,

Improving the Vehicular Engine Pre-Start and After-Start Heating by Using the Combined…

http://dx.doi.org/10.5772/intechopen.79467

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• maintaining the coolant and MO temperature within ≈50°C when the vehicle is stopped – TA + CTA + TASMO (ТHAМ = 85°С) + TASC (ТHAМ = 85°С) and phase-transitional TA;

• by total specific indicators - TA + CTA + TASMO (ТHAМ = 85°С) + TASC (ТHAМ = 85°С) and

To ensure the harmless environmental impact, it is expedient to use TAEGCS, TA + CTA + TASMO

To ensure the transportation comfort, it is expedient to use any means of thermal development in the engine CS. The best of them are – the vehicle - TA + CTA + TASMO (ТHAМ = 85°С), the vehicle - TA + CTA + TASMO (ТHAМ = 85°С) + TASC (ТHAМ = 85°С) and phase-transitional TA. In order to ensure the engine capacity at its start, that is the ability to have the load on the engine immediately after its start, it is expedient to use TAEGCS, the vehicle - TA + CTA + TASMO

In order to ensure specific efficient fuel consumption when maintaining the OT of engines and vehicles, it is expedient to use TA + CTA + TASMO (ТHAМ = 85°С) + TASC (ТHAМ = 85°С).

it is advisable to use the following options:

phase-transitional TA.

**Definitions/acronyms**

CC catalytic converter

CS cooling system

EG exhaust gases

CHS combined heating system

CTA contact thermal accumulator

EGCS exhaust gases cleaning system

• heating from *Т*amb. to 50°С - SS + RHE and phase-transitional TA; • heating from 50 to 85°С - SS + RHE and phase-transitional TA;

(ТHAМ = 85°С) + TASC (ТHAМ = 85°С) and phase-transitional TA.

(ТHAМ = 85°С) + TASC (ТHAМ = 85°С) and phase-transitional TA.

**Figure 7.** The results of investigating the influence of the CHS components on the coolant and MO heating time (a) and on the total time of the coolant and MO thermal development (b) in terms of fuel consumption (kg/h).

the interior and the driver are heated by the engine CS, that is, without changing the design of the vehicle. The results of the mathematical modeling of the interior heat transfer processes confirmed the feasibility of using the CHS. When using the CHS, the requirements are fully met in terms of the efficiency and safety of the heating system. It means that 15 min after the vehicle starts its motion at the ambient temperature to −25°C the requirements of the standard for heating the driver's head, legs, and body are fully met.

#### **6. Summary**

The development and the study of the engine combined heating system with phase-transitional thermal accumulators for pre-start and after-start heating under cold operating conditions were considered. To ensure optimal temperature condition of the ICE and the vehicle, general and individual tasks were determined. The combined heating system scheme of the ICE and the vehicle in operation was developed. The objects of experimental studies in operation were described. Using a systems approach to ensure optimal temperature condition of the vehicle in operation, the "combined heating system of the engine and the vehicle" and its application methods were developed. The results of significant impact of the combined heating system on thermal development indicators of the engine and the vehicle were obtained. The use of the combined heating system in the vehicular engine for different ambient temperatures enables to improve the indicators of the duration of coolant and motor oil thermal development. It is possible at: pre-start and after-start heating by 22.9–57.5% and 25–57%, and for a long storage ranging from 9 to 92 times and from 6.2 to 61 times, without the engine operation in an idling mode. The use of the combined heating system is generally effective for pre-start and after-start thermal development of the vehicular engine and for maintaining it for a long time when it is not running under different climatic conditions. The peculiarities of the combined heating system components and the technology for use are chosen depending on operational needs, climatic conditions and the category of the vehicle.

Thus, in order to ensure safety in terms of maintaining the OT of the engine and the vehicle, it is advisable to use the following options:


To ensure the harmless environmental impact, it is expedient to use TAEGCS, TA + CTA + TASMO (ТHAМ = 85°С) + TASC (ТHAМ = 85°С) and phase-transitional TA.

To ensure the transportation comfort, it is expedient to use any means of thermal development in the engine CS. The best of them are – the vehicle - TA + CTA + TASMO (ТHAМ = 85°С), the vehicle - TA + CTA + TASMO (ТHAМ = 85°С) + TASC (ТHAМ = 85°С) and phase-transitional TA.

In order to ensure the engine capacity at its start, that is the ability to have the load on the engine immediately after its start, it is expedient to use TAEGCS, the vehicle - TA + CTA + TASMO (ТHAМ = 85°С) + TASC (ТHAМ = 85°С) and phase-transitional TA.

In order to ensure specific efficient fuel consumption when maintaining the OT of engines and vehicles, it is expedient to use TA + CTA + TASMO (ТHAМ = 85°С) + TASC (ТHAМ = 85°С).
