CA2713264A1 - Method of operating a hybrid motor including external combustion engine, a source of energy made for solid biomass and accumulators - Google Patents

Abstract

This invention consists of a method for operating a hybrid vehicle formed by an external combustion engine, a solid biomass pellet tank and an accumulator (s); in order to meet the demand for energy. According to the principles of the present invention, the energy demand is planned and the energy flows through the system according to a predetermined operating mode in order to maximize efficiency. When the driver wants to make a journey, the energy demand to make this journey is planned according to various parameters which influence consumption. The production, storage and use of energy are modulated in real time according to the position of the vehicle in relation to the entire route. When the driver makes a demand for energy, the vehicle is prepared to meet this demand. Energy can come from the accumulators and / or from the external combustion engine. This type of management makes it possible to optimize each component according to the use of the vehicle and to avoid oversizing, undersizing, over-production of energy, under-production of energy, over-storage of energy, an energy storage.

Description

FIELD OF THE INVENTION

The efficiency of internal combustion engines is about 15%. That means that only 15% of the energy in the fuel is used to drive the vehicle.
Energy is mostly lost as heat through the exhaust system, the system of cooling and braking system.

Electric motors have a high efficiency. Losses are of the order 10%. The loss are 5% for high efficiency electric motors. Also, the engines electric can be controlled by electronic components. There are different types of control as per example the control of the speed of rotation.

Electric vehicles running only with a battery like source of energy have the reputation of having a limited range, a slow cooldown.
Also the cost of batteries is high. The number of refills is limited. Raw materials for the manufacture batteries are non-renewable resources.

Hybrid motor refers to a motor that uses more than one source energy and / or more than one type of engine. For example, the Toyota Prius uses a petrol engine and electricity. The purpose of a hybrid engine is to manage the operation for get an efficiency improve. This allows the hybrid vehicle to have a consumption in fuel that is lower in urban driving compared to driving on the road.

Generally, the main source of energy allowing the movement of a hybrid vehicle is an internal combustion engine powered by a tank which contains a liquid fuel and a electric motor powered by batteries. The electric motor allows recover a part of braking energy and directed to a storage device like The batteries electric.
It is possible to produce solid bio fuel also called granules of using wood fast growing plants. Willow shrub (Salix), switchgrass (Panicum), the hybrid poplar (Populus) are some plants that can be used for organic production solid fuel.

Keeping the fuel in solid form avoids the losses incurred by transformation from a solid product to a liquid product. To transform plants into organic liquid fuel (ethanol) requires complex processes that consume large quantities of amounts of energy. The bio solid fuel production requires modest equipment that consumes little energy. This helps to be carbon neutral. Fixed plants the carbon during their growth and carbon is released during combustion.

Energy from solid bio mass pellets and energy from the accumulator complete. Accumulators have a fast response time and the engine to external combustion allows a high autonomy.

2 So, there is a need for a new and improved method that produces results to control a hybrid engine powered with a bio fuel solid for the purpose of propel a vehicle.

SUMMARY OF THE INVENTION

This invention consists of a new method and improve control for a motor hybrid fueled with a solid bio fuel in order to maximize energy efficiency and to make the driving of a vehicle reliable.

According to the principles of the present invention, when there is a demand for energy out of the hybrid engine, the electrical energy directed to the output may come from different sources.
The energy can come from the accumulator (s) and / or the combustion engine external. The choice of the source depends on different factors. It depends on the energy available, of the estimate of the energy that will be needed for a fixed duration and the response time sources energy. In the case of a vehicle, the energy estimate is based on the distance to browse, speed, load to tow, vehicle position (System of Positionnent).
Data such as route type (urban, highway), topography (relief), the density of traffic, weather conditions, road quality, road in repair, as well as other conditions that could influence the management of consumption are placed in a Internet server. These data are not influenced by the type of vehicle but they influences energy management.

The main source of energy comes from the external combustion engine, it is important of good plan the use of the firebox. Initially, the chamber of combustion is cold it is necessary to send fuel inside and proceed to ignition. it can do this with electrodes or resistors or other devices (not shown on the drawing). Once heated combustion chamber, the combustion chamber must be kept hot for the entire duration of the course.

One liter of gasoline contains 9.7 kWh of energy (evaluated in calorific value superior) One kilogram of solid bio mass pellets contains 5 kWh of energy.
So the energy contained in a 51-liter gas tank corresponds to about 100 kg of bio solid fuel.

Knowing the position in real time and the energy demand for the next steps allows to prepare the production and storage of energy according to response time and current storage levels.

If the system plans to have low power consumption for a determined distance, the system sending the minimum amount of fuel into the combustion chamber for the external combustion engine and the accumulator (s) can meet the planned request.

If the system plans to have a high energy consumption for a determined distance, the system sending a higher amount of fuel into the chamber of combustion so that the external combustion engine and the accumulator (s) can meet the planned request.

j If necessary, the external combustion engine must produce surpluses are directed to the accumulator (s).

The charge level of the accumulators must be maintained over a minimum limit for do not damage the batteries. Accumulators are used to the maximum to improve efficiency and allow charging during periods of downtime. By example, as we approach end point, the system may decrease the temperature of the chamber of combustion and use at the maximum accumulators.

Energy management is done in two levels. The first level consists of management on the whole journey. The second level consists of event management punctual as for example unplanned braking and accelerations.

In the case of a new course. The user indicates the point of arrival. The system of positioning determines the initial position. The computer receives the data of the server on the shape of the road and other variables. The computer traces a route in order to make an optimal assessment of energy management.

In the case of a repeated journey, for example for vehicles transportation common delivery vehicles. The course is recorded and the system make an evaluation performance in order to improve efficiency. The computer receives external data which influences consumption.

In the case of unforeseen events, the system must be capable of sufficient for there to be no interruption and have time to readjust the energy levels in according to his new position.

During braking, the energy can be recovered. This energy can be directed to the accumulator (s) or to a heat exchanger (s). This is the system of management that determines which is the most efficient according to the energy level of the accumulators, the use of the engine external combustion and energy demand for the rest of the course.
For a vehicle conventional, acceleration and braking account for about 6% of the energy consumed urban driving and 2% driving on the road. When the driver does a request of braking is the conventional brake that starts braking. A percentage or the whole Braking is transferred to the recovery system safely.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a hybrid vehicle fueling organic solid fuel.
FIG. 2 is a logic diagram for the control of the operating system of a powered vehicle by hybrid engine.
FIG. 3 is a graphical representation of the distribution of demand in planned energy.
FIG. 4 is a logic diagram of the management of the operation of the chamber of combustion and the external combustion engine according to the planned demand at the FIG. 3.
FIG. 5 is a logic diagram of the acceleration management for a hybrid vehicle feed with a solid bio fuel.

FIG. 6 is a logic diagram of the braking management of a vehicle hybrid feed with a solid bio fuel.
FIG. 7 is a schematic diagram of an exemplary hydraulic accumulator.
DETAILED DESCRIPTION OF THE INVENTION

In the following description, the term solid bio-fuel refers to granules formed with plants also called wood pellets.

The term external combustion engine refers to an engine that uses a fluid motor and a cycle thermodynamic. The working fluid evolves according to a cycle then returns to its initial state. A
example of this type of cycle is the steam power cycle called cycle of Rankine. For make the drawing clearer, the regeneration cycle is not shown.

The term accumulator refers to storage devices such as electric batteries, super-capacitors, flywheels, accumulators hydraulic, batteries oleopneumatic, hydropneumatic batteries as well as systems similar.

The term global positioning system refers to a system capable of determine where the vehicle is. It allows to know the position in time real.

The term electric motor refers to a motor that drives the wheel and allows the recovery of kinetic energy during braking.

The term load to tow represents the fixed load and the loads variables.

The term variable factors represents all the external factors such as that the factors climate (temperature, winds), the shape of the road (slope intensity), quality of the road, flow of traffic.

The term available energy represents the energy stored in the Accumulators electrical, mechanical and thermal.

The term response time refers to the time that elapses between the time of the request in energy and the moment that energy is delivered.

Application According to the principles of the present invention, if a person wants to make a course with a vehicle powered by the hybrid engine 1O (FIG. 1), a set of information have entered the central control unit 12, to enable the management of energy.
The user must provide the point of arrival and the towed load (the towed load can be measured by sensors).
The global positioning system 14 indicates the position in real time. The server 16 transmits a set of information (variable factors) from outside. Examples variable factors are distance, speed, conditions climate (temperature, direction and intensity of the wind, rain, snow, ice), type of trip (city, road), topography (location of positive and negative slopes, slope intensity, curves), quality of the road, traffic density (position of the traffic jams), as well as other conditions that could influence the management of consumption such as the need for heating and air conditioner.

FIG. 1 shows the elements that make up the entire hybrid engine 10.
When the driver makes a demand for energy, the energy comes from accumulator (s) 42 and / or external combustion engine 26. The working fluid is converted into steam by the room combustion 20. The combustion chamber is fed by a bio tank solid mass 18.
Steam can be stored in a tank 22. The valve 24 allows to operate the engine 26.
After leaving the motor 26, the fluid passes through the condenser 28. The fluid can then be pumped by the pump 30 and the cycle starts again. The air that enters the room of combustion is heated by the exhaust gases in the heat exchanger 34.
exhaust gas pass through an anti-pollution system 36. The ashes are recovered by a tank 38. The motor 26 drives alternator / generator 40 by actuating clutch 54.
The engine to External combustion can also drive the wheel 60 by operating the clutch 56.

To determine how much energy comes from the accumulator (s) 42 and how much energy comes from the engine 26, the central control unit 12 makes a management based on knowledge of the whole journey to go. The positioning system 14 indicates the position in time real. The server 16 indicates changes that could influence the consumption. The switch 48 makes it possible to direct the energy towards the speed control 44 or towards the accumulator (s) 42. The switch 50 makes it possible to direct the energy of the accumulator (s) 42 to the speed control 44. The electric motor 58 converts the energy electric from speed control 44 in rotational movement of the wheel 60.

In the case of braking, kinetic energy is converted into energy electric by motor / brake 58. The energy is transformed by brake control 46 to be directed to the accumulator (s) 42 or to the heat exchanger 32 via the switch 52.

FIG. 2 shows a characteristic of this management system. By knowing the point of arrival (step 201), the control unit 12 (FIG. 1), makes an evaluation (step 203) to determine if the trip is new. If the journey is not new then the estimate of energy is based on comparable prior data (step 204). This estimate takes into account factors variables at step 202. If the path is new (step 203), the unit of control 12 (FIG.1) makes a research to determine if the end point is known (step 206). If the point is unknown, then the control unit 12 does an interpolation based the known point the closer (step 207). If the point of arrival is new and known, then the control unit 12 (FIG.1) makes a estimating the energy required (step 208).

FIG. 3 represents an example of an estimate of the energy consumed for all of one path. The equation of curve 301 indicates the energy estimate consumed according to the position. The central control unit 12 (FIG. 1) must prepare the production and the distribution of the energy according to the response times. For example if the vehicle is located at point A, then the central control unit 12 FIG.1 must plan the energy management to answer the request scheduling for the AB interval. This is a continuous process on the entire duration of course because consumption is not linear.

There are 2 types of management.

Long-term management.
It's management over the entire journey, this type of management is represented by an example to the FIG.3. It is based on the maximum of information. The response times are different.
The electric accumulator has a fast response time. In a way general, the batteries electrical appliances have the ability to provide a strong electrical current during a short period of time. The response time of the external combustion engine is relatively slow because the fluid motor must travel the entire circuit to power the motor to external combustion. It is why it is important to have good planning. Accumulators have a intermediate response time.

FIG. 4 represents the management of the external combustion engine. Temperature of the room combustion is adjusted (step 401) according to the planned demand in FIG.
FIG.3. Steam may be stored in a tank (s) (step 402) depending on the pressure level optimum and safe. The external combustion engine is operated to meet the planned request in respecting the response times at step 403. The external combustion engine must produce surplus to adjust the energy level of the accumulators (404) and minimize the charges and discharges of accumulators.

In the case of acceleration, FIG. 5 represents a strategy for the Energy management. Yes we start from the stop position (speed equal to zero), the energy comes from of the accumulator electrical (step 501) (FIG.1). This allows to begin the propulsion of the vehicle. As soon as the energy from the mechanical accumulator is available (step 503) (42 FIG.1) is the mechanical accumulator that takes over. The transition must be done gradually to avoid shaking. Once the mechanical accumulator has finished provide energy, external combustion engine takes over (step 506) (FIG.1). The transition must be done gradually. This is the position of the contacts on switches 48 and 50 FIG. 1 which allows choose the flow of electrical energy. The passage of the accumulator electric to the mechanical accumulator then to the external combustion engine is determined, in part, by the estimate of the energy that will be consumed (FIGS. 2 and 3). It is by operating the clutch (56 FIG. 1) that the external combustion engine supports and replace the electric motor (58 FIG.1). The clutch (54 FIG.1) allows the external combustion engine (26 FIG.1) to operate the alternator / generator (40 FIG.1). Alternator / generator can route electrical energy to the accumulator (s) (42 FIG.1) or to the motor (58 FIG.1) in selecting the position of switch (48 and 50 FIG. The surplus energy produced by the engine to external combustion (Fig. 1) are directed to the battery (42). This evaluation is prepared so continuous, so that if the driver presses on the accelerator, the system is ready to react.

In the case of an acceleration from a constant speed different from 0, then FIG.5 apply. However, the external combustion engine 26 is already in surgery. Engine electrical 58 then comes in support, the time that the combustion engine external adjusts according to the speed required and the consumption forecasts for next steps.
In the case of a recovery (after braking), the speed of the vehicle is different from 0. FIG.5 apply. It is the electric motor 58 that is the first to answer the request. Load is gradually transferred to the external combustion engine 26.

In the case where the vehicle has to climb a steep slope, the two engines 26 and 58 can work together for a short period of time in order to meet the request. It is necessary keep in mind that the vehicle knows before starting a climb it must to have some amount of energy in the accumulators 42 and that it must also prepare the energy production of the external combustion engine 26 according to the energy that it will have provide.

In the case of braking (FIG. 6), the strategy is to transfer the conventional braking 601) to braking capable of recovering kinetic energy. The battery mechanical allows absorb the braking energy and return it quickly. Yes the mechanical accumulator is not available to store energy so check if the accumulator electric is available to receive energy (step 603). Generally, batteries have a time of load that is relatively slow. A quick charge could damage the batteries. If the accumulators are charged or the braking speed is too high (too much available energy for a short time), then the kinetic energy from braking is directed to the heat exchanger (step 604). The electric current generated by the motor / brake Electromagnetic (58 FIG.1) is routed to the heat exchanger (32).
FIG. 1). This exchanger consists of resistors that will transform the energy electric heat. This heat is recovered by warming the fluid that is directed to the chamber of combustion (20 FIG. 1) (regeneration). If none of the energy recovery devices is not available, so it is the conventional braking system that is actuated at step 605 (system not shown).
This assessment is prepared on an ongoing basis, so that if the driver press on the brake, system is ready to react. The systems can operate simultaneously, by example, the Breakdown distribution could be 20% conventional braking, 80% braking regenerative.

There is also short-term management.
It's the management of stops, starts, accelerations, decelerations not planned. These variations are damped by the accumulator (s) (42 FIG 1). It exists different type of accumulators mechanical devices such as flywheels, batteries oleopneumatics, hydropneumatic accumulators, hydraulic accumulators.
The privileged accumulator for this type of variation is the mechanical accumulator. This reduces the use of electric accumulators like chemical batteries and to increase their lifetime. The FIG. 7 is a schematic example of a hydraulic accumulator. In pressing the clutch 82 and the valve 74, the control 12 allows the pump to transfer the fluid contained in the tank 70 to the cylinder 76. The pumping completed, the valve 74 is closed for conserved energy. To recover stored energy, valve 74 is opened. The spring 78 placed in the cylinder 76 returns the fluid to the tank 70 while passing by the pump 72. The pump drives the wheel 60 by actuating the clutch 82.

Knowing the distance and the recharge time makes it possible to design a system with optimum dimensions for the different components like the combustion engine external accumulators, electric motors. This means that the configuration could be very different depending on the type of vehicle and its use.

A skilled person in the field will notice that steps can to be withdrawn, added and / or executed in a different order.
Several modifications can be made without deviating from the spirit of the present invention.

Claims (9)

The claims are: 1. Method for operating a hybrid engine comprising a combustion engine external, a energy source formed of solid bio mass and accumulator (s).
The method included;
A system capable of measuring available energy levels in real time.
A system capable of estimating the required energy demand for make a course determine.
A system capable of anticipating energy demand by taking into account its position in real time.
A system capable of planning the production of energy based on estimating energy demand, speed of energy production and the ability storage.
A system capable of choosing the optimal distribution of energy based on the estimate of the demand for energy.
A system able to choose the optimal recovery of energy by holding account of his real time position.
A system able to evaluate the response time of different sources energy. The method of claim 1, wherein the set of data that influences the consumption of a route are contained in a computer server for a transmission to the central control unit at the appropriate time. The method of claim 1, wherein the temperature of the combustion chamber, the production of steam and steam storage are adjust between a maximum level and a minimum level allowed by the solid fuel supply system and the system of combustion. The method of claim 1, wherein the energy source varies according to the time of source response. In acceleration mode, the first choice for the source of energy is the chemical accumulator, the second choice is the mechanical accumulator, the third choice is the external combustion engine. The method of claim 1, wherein the recovery of the braking energy varies depending on the response time and the availability of recovery systems. The first choice for the recovery of energy is the mechanical accumulator, the second choice is the accumulator chemical, the third choice is the heat exchanger. The method of claim 1, wherein the energy levels of the different sources are adjusted in preparation for the estimated demand. 7.Method according to claim 1, wherein the external combustion engine operated by steam can be replaced by a conventional internal combustion engine or a motor Stirling type. 8.The method of claim 1, wherein the accumulator is constituted different devices like 1) chemical batteries 2) ultra capacitors 3) wheels of inertia 4) hydraulic accumulators 5) oleopneumatic accumulators 6) Accumulators hydropneumatic. 9.The method of claim 1, wherein the system has a margin sufficient for absorb unplanned variations.