Regasification apparatus for the supply of vehicles' endothermic engines

Abstract

A regasification apparatus includes a closed loop heat transfer fluid circulation assembly, for the storage of the cold energy extracted from fuel during its regasification, and provides: a first tank, for containing at ambient temperature the heat transfer fluid, and an insulated second tank where the latter is kept cold; a fluid/fluid heat exchanger, defining the heating means, in which the fluid, coming out of the first tank, is placed in heat transfer with the cold branch of the pipe and therefore cooled, then stored in the second tank. From the latter departs at least one insulated branch, to supply with cold fluid at least one utility present in the aforementioned vehicle, for example an air/fluid heat exchanger located downstream an intercooler of the engine. By means of a pipe, the heat transfer fluid, heated back to ambient temperature, returns to the first tank.

Claims

1. A regasification apparatus for a supply of a vehicle's endothermic engine of the type in which there is provided at least one cryogenic cylinder for the storage, in liquid form, of a fuel gas mixture, beating means interposed along a fuel supply pipe connecting the cryogenic cylinder to the fuel supply system of the engine, operable to heat the fuel gas mixture in liquid form from a sub-zero temperature from which it is taken, to bring it back to a gaseous state at a temperature compatible with the fuel supply system of the engine, and a closed loop circulation assembly where a heat transfer fluid is circulated, for the storage of cold energy extracted from the fuel gas mixture during a heating phase, comprising: a first tank, adapted to store, at ambient temperature, a volume not less than 0.1 m.sup.3 of the heat transfer fluid in liquid phase; means for the withdrawal, with a controlled flow rate, of the fluid from the first tank and for flowing it through a first pipe; a fluid/fluid heat exchanger, defining the heating means and located downstream of the first pipe between the cryogenic cylinder and the fuel supply system of the engine, in which the heat transfer fluid exchanges heat with a cold branch of the fuel supply pipe, thereby lowering its temperature; an insulated second tank adapted to store a volume not less than 0.1 m.sup.3 of the heat transfer fluid in liquid phase; an insulated second pipe, at an output of the fluid/fluid heat exchanger, for conveying the cooled heat transfer fluid to the second tank: at least one insulated derivative piping connected to the second tank for receiving the cold heat transfer fluid and conveying it to at least one of a plurality of utilities present in the vehicle in which a cooling action is required, the at least one utility being not in thermal contact with the first tank and second tank and a third pipe, placed downstream of the at least one utility, for returning the heat transfer fluid, heated back to ambient temperature, into the first tank.

2. The regasification apparatus according to claim 1, wherein the fluid/fluid heat exchanger is of the indirect type, providing a double circuit inside it, in which an intermediate heat exchanger fluid is circulated, provided for exchanging heat between the fuel gas mixture in liquid state and the heat transfer fluid.

3. The regasification apparatus according to claim 1, further comprising a heat transfer fluid circulating in the closed loop circulation assembly, the heat transfer fluid being an antifreeze liquid which is in liquid phase at ambient pressure and at a temperature of −15° C.

4. The regasification apparatus according to claim 3, wherein the antifreeze liquid is a mixture of water and ethylene glycol operable to keep the antifreeze fluid in the liquid state up to at least a temperature of −15° C., and wherein the intermediate heat transfer fluid is a pressurized inert gas including nitrogen, helium, a hydrocarbon or mixtures thereof, operable to work at a temperature equal or lower than −150° C. without incurring in a phase change.

5. The regasification apparatus according to claim 1, further comprising a programmable management system operable to define control parameters according to which the cold heat transfer fluid is supplied to the at least one utility.

6. The regasification apparatus according to claim 5, wherein the programmable management system is interfaced by least one remote device provided for receiving and transmitting data from or to the programmable management system.

7. The regasification apparatus according to claim 6, wherein the utility is an air/fluid heat exchanger or aftercooler placed downstream an air/air heat exchanger of the engine, wherein the programmable management system is adapted to control the supply of the cold heat transfer fluid from the second tank to the utility, so as to enable activation of the aftercooler, as a function of settable parameters including the vehicle's weight, load conditions and information from on board or the at least one remote device about the route, traffic, weather conditions, or expected time of arrival received from the at least one remote device operable for setting optimal parameters for the operation of the engine.

8. The regasification apparatus according to claim 5, wherein programmable management system is interfaced with at least one device located on board of the vehicle, operable to provide specific information to the management system useful for defining or correcting the control parameters according to which the cold fluid is supplied to the at least one utility.

9. The regasification apparatus according to claim 5, wherein the insulated derivative piping comprises a cold collector or distributor and the third pipe comprises a hot collector, wherein the plurality of utilities are included between the cold collector or distributor and the hot collector, wherein the programmable management system is operable for controlling the cold collector or distributor to manage the supply of the cold heat transfer fluid to each of the plurality of utilities.

10. The regasification apparatus according to claim 1, wherein each of the first tank and second tank is adapted to contain a volume of the heat transfer fluid in a range of 0.25 m.sup.3 to 0.5 m.sup.3.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The characteristics of the invention will be clear from the following description of a preferred embodiment of the main elements of a regasification apparatus for the supply of vehicles' endothermic engines, in accordance with the provisions of the claims and with the aid of the attached drawing, in which FIG. 1 shows a schematic block view of the apparatus of the invention in a vehicle equipped with an endothermic engine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

(2) In the aforesaid FIGURE it is pointed as whole with reference sign 1 a regasification apparatus of the invention, intended for supplying with fuel an endothermic engine M of a vehicle (not shown). Preferably, although not necessarily, said endothermic engine M is of the Otto cycle spark ignition type, applied to large industrial vehicles, such as trucks, buses, earth-moving machines and the like, as well as to agricultural tractors.

(3) The apparatus 1, in a manner known per se, comprises at least one cryogenic cylinder H for storing, in liquid form, a fuel gas mixture, for example natural gas such as methane, and heating means C, placed along a pipe 3 connecting said cryogenic tank H with the engine's fuel supply system, said heating means being suitable for heating the fuel in liquid form, from the sub-zero temperature (−150/−160° C.) at which it is taken from the cryogenic tank, for example by means of a suitable pump 2, to bring it back to the gaseous state and to a temperature compatible with the power supply of the same engine M.

(4) The apparatus 1, according to the invention, comprises a closed loop circulation assembly, 10, for circulating a heat transfer fluid, adapted for storing the cold energy extracted from the said fuel gas mixture during its heating for regasification.

(5) The heat transfer fluid is an antifreeze liquid made, as a non-limiting example, of a mixture of water with a high content (20-50%) of ethylene glycol or other suitable substance to ensure that it remains in liquid phase, at atmospheric pressure, up to about −15° C.

(6) The assembly 10 comprises the elements described below, enclosed within the dotted line K in the attached FIGURE.

(7) In said elements, a first tank A is provided, suitable for containing, at ambient temperature, a volume of not less than 0.1 m.sup.3, preferably higher than 0.2 m.sup.3, of said antifreeze fluid in liquid phase.

(8) From the first tank A, through a proper device 11, for example a valve, the antifreeze fluid flows, with controlled flow rate, into a first duct 12, which conveys to a fluid/fluid heat exchanger 13, which also defines in the present embodiment, said heating means C.

(9) In said fluid/fluid heat exchanger 13, the antifreeze fluid exchanges heat with the cold branch of the aforementioned pipe 3 between the cryogenic cylinder H and the fuel supply system of the engine M, thereby undergoing a lowering of its temperature.

(10) Advantageously, the fluid/fluid heat exchanger 13 is of the indirect type, providing a double circuit 13C inside it, in which an intermediate heat exchanger fluid is circulated, provided for exchanging heat between the cold fuel in liquid form and said antifreeze fluid. The intermediate heat transfer fluid is an inert pressurized gas, (for example, Nitrogen or Helium), a pure hydrocarbon or mixture of hydrocarbons thereof suitable for operating at a temperature lower than −150° C. without incurring in a phase change. At the same time, also the intermediate heat transfer fluid extracts heat from the antifreeze fluid without causing a phase change of the latter.

(11) An insulated second pipe 14 exits from the fluid/fluid heat exchanger 13, for the transport of the cooled antifreeze fluid to an insulated second tank, B, for example with a double wall and adequately insulated to minimize heat transfer between the cold fluid contained therein and the external environment. The second tank B is also suitable for containing a volume of not less than 0.1 m.sup.3, preferably larger than 0.2 m.sup.3, of said antifreeze fluid in the liquid phase.

(12) The second tank B is suitable to keep the cold antifreeze fluid stored as long as it is not required to be used (up to several hours).

(13) From the second tank B departs at least one insulated derivative pipe 15, for conveying cold fluid to a user U1 present in the aforementioned vehicle, in which cooling action is required. In the accompanying FIGURE, the insulated derivative pipe 15 comprises a first branch 15A along which a delivery pump N is arranged, suitable for keeping a cold collector/distributor, D, moderately pressurized to which said first branch 15A leads. The cold collector/distributor D has advantageously multiple outputs: in the illustrated example, the second branch 15B of the aforementioned insulated derivative pipe 15 is connected to an output; similarly, other outputs are suitable to be connected with further insulated branches 16, 17, for conveying cold fluid to corresponding users U2, U3.

(14) The utilities U1, U2, U3 and any others can be of various types, such as, for example, a cooling room for keeping refrigerated a load in the vehicle, the air-conditioning system of the cabin, cooling means for cooling mechanical organs and further more.

(15) The insulated derivative pipe 15 is advantageously intended to serve a user U1, located in the aforementioned fuel supply system of the engine M, which is supercharged by a turbocharger G in this embodiment of the invention. The utility U1 is located downstream of an air/air heat exchanger F, or intercooler, provided in a known manner in the engine M, for a first cooling of the intake air. Said utility U1 is an air/fluid heat exchanger E, or aftercooler, in which the cold fluid coming from the second tank B performs a further and more accentuated cooling of the same combustion air entering the engine M. This allows to considerably increase the density of the air introduced into the engine M, thus improving its volumetric efficiency and, therefore, its performance.

(16) From the utility U1, that is the air/fluid heat exchanger E (aftercooler), a third pipe 18 departs for conveying the fluid, heated back to ambient temperature, in said first tank A. In the present embodiment, in which there are several utilities, a hot collector L is associated with the third pipe 18, and the hot collector L receives the heat transfer fluid from several branches 18B, 18C for the return of the fluid flow from the respective users U2, U3. Between the utilities U1, U2 and U3 and the first tank A, the manifold L is interposed and, similarly, between the second tank B and the users U1, U2 and U3 the manifold D is interposed. Between the utilities and the two tanks there is not substantially any heat exchange.

(17) In the apparatus 1, a programmable management system 20 is provided, schematically indicated by a dotted line in the attached diagram. The programmable management system 20, consisting of conventional electronic devices either hardware and software, is designed to control the parameters according to which the utility(ies) is (are) supplied with cold fluid. These parameters are calibrated to achieve the best time to time performance. In the presence of a plurality of users, the programmable management system 20 is adapted to control said cold collector/distributor D to manage the supply parameters of each utility. An interface between the programmable management system 20 and the operator can be located on board of the vehicle and, in addition or alternatively, include a remote device, connected in radiofrequency, for example a tablet, a smartphone or the like, capable of receiving and transmitting data from/to the system 20 itself. As a further possible embodiment, the programmable management system 20 is interfaced with at least one device located on board of the vehicle, for example a satellite navigator or a GPS, designed to provide specific information to the system 20 in real time, useful for the selection or the correction of the aforementioned supply parameters of an user. For example, depending on the planned route, traffic, weather conditions, expected time of arrival, or any other data that may serve the purpose, the programmable management system 20 can set the optimal cold energy supply parameters for each utility (engine operation, refrigeration of the load, air conditioning of the passenger compartment, cooling of mechanical members and even more).

(18) From the above description, it is intuitive to understand the peculiar characteristics of the regasification apparatus proposed with the present invention, which combines the primary function of supplying vehicle's endothermic engines with a fuel which is a mixture of combustible gas previously stored in liquid form in a cryogenic cylinder, together with the functions of: storing the cold energy extracted from the fuel during the regasification process in an antifreeze fluid; managing the stored cold energy; and supplying the stored cold energy in a delayed manner to one or more users on board of the vehicle according to variable and selectable modes. It is done by an optimisation procedure, managed on board of the vehicle based on the artificial intelligence and on the collection of external data (position, traffic, weather conditions etc.) and on self learning.

(19) Thanks to the technical solution providing a closed loop heat transfer fluid circuit comprising a cold and a hot tank, it is possible to extract the maximum amount of cold energy from the fuel and keep it stored with a low heat loss. The use of an antifreeze fluid as the heat transfer fluid allows a heat exchange without using a phase change fluid and thus a great simplification of the closed loop heat transfer fluid circuit. Moreover, the first tank A and the insulated second tank B are materially and thermally completely separated from the utilities U1, U2 and U3, so that the cold energy can be stored for a delayed use. Thanks to the presence of the hot and cold collectors L and D placed between the tanks A and B and the utilities U1, U2, and U3, it is possible to manage a plurality of utilities in order to optimize the exploitation of the cold energy stored in the second tank B.

(20) Indicatively, for a commercial truck with power output in the range 200-300 kW, the two tanks A and B have advantageously a capacity of 0.25-0.5 m.sup.3 each, corresponding to a stored cold energy estimated between 7 and 14 KWh, which can be accumulated in about 1-2 hours of operation of the engine through the heat exchanger 13. Then, the stored cold energy can be distributed at any time to the utilities that need it. In particular, the management system 20 is configured to decide the use of the cold energy on the basis of the cooling requirements of the loads, that are largely a priori programmable. Furthermore, the supply of cold energy to the aftercooler E, which is conveniently activated depending on the performance and working regime required to the engine M, can be determined automatically by the management system 20 itself as a function of settable parameters such as the vehicle's weight, load conditions and also thanks to the presence on board of communication devices that allow to obtain information on the route to be taken such as, for example, the slopes to be overcome, the average speeds, the traffic along the route, the weather conditions, in order to predict the engine operating regimes and, therefore, the need for activation of the aftercooler E.

(21) Advantageously, by combining the programmable management system whose potentials and functions are certainly larger than the ones described as a non-limiting example, the use of the stored cold energy can be calibrated according to the real need of the user, with the least waste possible, so as to obtain, on the whole, a high cold energy exploitation efficiency. It is also possible to combine a control system with self-learning functions that are able, especially under repetitive service conditions such as those occurring in public transport or planned logistics, to setup and adjust the working parameters to optimize the use of cold energy.

(22) To this end, the ability of connecting the managing system 20 with remote devices such as smartphones and the like, and/or with on-board systems able to interact with the apparatus of the invention are useful to optimize the operation of the apparatus itself.

(23) However, it is understood that the above description has an exemplifying and non-limiting value, therefore any variants of details of components of the described apparatus that may be necessary for technical and/or functional reasons are considered from now on falling within the same protective scope defined by the following claims.