Patent Description:
The long-term stability and growth of an economy requires an adequate supply of energy, and in particular, electrical energy. In many of the cases in which a power supply is required, it needs to be highly reliable, not allowing power outages in locations with high requirements, such as hospitals, data and telecommunications centers, continuous production industries, etc..

In this sense, the use of generator sets is essential for the development of emergency systems that make it possible to make up for deficiencies or outages in power supply, as well as the absence thereof, thus ensuring continuity in the operation of electrical equipment.

Currently, most of the generator sets developed are oversized to deliver the power demanded, which is why low levels of energy efficiency, high operating costs and fuel consumption and polluting emissions are achieved, in addition to incurring in high costs derived from the maintenance of equipment.

Among the latest technologies implemented in the generator sets, there are pieces of equipment with a speed variator that allow the generation of electric current to be adapted to the power demanded at each moment, which are considered high efficiency alternatives. Other technologies implemented, such as electronic control or automatic voltage regulator, allow the equipment to operate autonomously and remotely, optimizing the variables of the equipment based on demand and allowing the management of equipment operation and component maintenance through different telecommunication systems.

Among the generator sets intended for rental applications (also called rental applications), the most widespread and used generators are electric generators with diesel engines, which have the following drawbacks:.

Within the gas-based electric generators, all of them have external fuel tanks, which require their corresponding transportation and installation in each work location, including the logistics associated with said activities. The fuel is stored in pressurized tanks that are very sensitive to both high temperatures and sparks that can initiate any gas leakage.

Due to the safety characteristics of gas tanks and the conditions of the generator sets, the gas tanks where the fuel is stored for its operation are independent elements from the generator sets themselves, so the complete transport involves the use of two vehicles and two trailers, or a large transport vehicle which implies the establishment of complex and expensive logistics.

In addition, the installation of the electric generators in each location requires both the installation of the generator set, the installation of the gas tank and the gas pipes necessary to carry the fuel to the engine of the generator set.

Thus, considering the products available on the market, versatile and robust solutions that combine the characteristics demanded by the use of gas-based electric generators for the rental sector have not yet been developed, since there are compact electric generators that use liquefied petroleum gases as fuel, but all of them have gas storage tanks as elements unrelated to the generator itself.

Therefore, there is a fervent demand in the field of gas-based electric generators for the rental application sector for the development of an electric generator that integrates a generator set and gas tanks in the same structure in order to facilitate the relocation of said electric generators without having to transport two different pieces of equipment, thus avoiding the use of two towing vehicles or equipment transport vehicles for the generator set and for the fuel tank. One such genset can be found in <CIT>.

The present invention satisfies this demand.

The electric generator according to the present invention arises from the high inefficiency associated with the relocation of the generator sets powered by LPG, used in the rental applications sector. Due to the characteristics of the sector, in which generator sets are rented to provide energy for different events and applications, in different locations that require the transfer of the elements that allow electricity generation, which mainly include the generator set and the fuel tank(s).

In a first aspect, the present invention relates to an electric generator comprising a frame defining a first compartment and a second compartment. The generator comprises a generator set established in the first compartment. Innovatively, the electric generator comprises at least one tank of liquefied petroleum gas, LPG, established in the second compartment and a liquid-phase feed gas train that connects said tank to the generator set for the supply of LPG.

Thus, the present invention consists of new electrical generation equipment supplied entirely with liquefied petroleum gases LPG in which the LPG tank itself is integrated with the generator set in the same single structure or frame.

The exclusive use of a gaseous fuel source requires that the tank be pressurized and, therefore, the generator can include auxiliary systems to condition said fuel.

The present invention focuses on applications of generator sets that use LPG as fuel for electricity generation for the rental sector, which is strongly driven by aspects such as noise pollution, engine efficiency, gas emissions and eventual increase in energy demand. Thus, the present invention relates to an electric generator that allows reducing the logistics necessary for uses and applications involving frequent relocation.

In this way, the electric generator according to the present invention intends to respond to the needs of the rental sector by developing compact generator equipment that integrates the LPG fuel tanks in the same equipment, maintaining the conditions of safety, autonomy and compactness and increasing ease of transfer while reducing the logistics required for relocation.

In two preferred embodiments, the generator sets according to the present invention comprise four different powers, one of <NUM>, <NUM>, <NUM> and <NUM> kVA, which allow their application to be validated within the ranges of the range intended for the rental sector.

In a preferred embodiment, the generator comprises three LPG tanks with a useful capacity of <NUM> liters. The LPG tanks are sized to ensure autonomy of at least <NUM> hours in the preferred embodiment of <NUM> kVA, operating at a normal regime of <NUM>% of the nominal load of the generator set of the electric generator.

The electric generator includes a single filling point for the three tanks. The electric generator includes a system for external feeding both in liquid phase and in vapor phase.

Additionally for the gaseous phase, the electric generator may comprise a second gas train that connects a gas source external to the electric generator to the generator set for the supply of LPG.

In addition, the electric generator accepts motorization and generators for both <NUM> and <NUM>.

The electric generator comprises a frame that defines two compartments which can be divided by a rock wool partition or the like in a first embodiment and by a sub-frame in a second embodiment.

The electric generator comprises at least two gas sensors, one in each compartment of the frame to increase safety. The generator can be programmed to stop its operation immediately after detecting a presence of gas above the established limit.

The electric generator includes safety valves and conduits that evacuate the gas to the outside of the generator set in the event that excess pressure is detected inside the fuel tanks.

To complement the description that is being made and in order to help a better understanding of the features of the electric generator, according to a preferred example of its practical embodiment, a set of drawings is attached as an integral part of said description, wherein by way of illustration and not limitation, the following has been represented:.

The electric generator (<NUM>) shown in <FIG> powered by LPG comprises a single frame (<NUM>) which is shown in its entirety in <FIG>. The electric generator (<NUM>) also comprises a generator set (<NUM>) and a set of pressurized LPG tanks or reservoirs (<NUM>), in particular, three LPG tanks, which are shown in <FIG>. The electric generator (<NUM>) of <FIG> has a power of <NUM> kVA. In other preferred embodiments, the electric generator (<NUM>) can have powers of <NUM>, <NUM> and <NUM> kVA. The three LPG tanks or reservoirs (<NUM>) have a useful capacity of <NUM> liters, which may require <NUM> minutes to be fully refueled.

With regard to the frame (<NUM>), it comprises inside a first part or compartment (110a) and a second part or compartment (110b) as can be seen in <FIG>. The frame (<NUM>) of the electric generator (<NUM>) includes a separation partition or barrier (<NUM>) and a casing (<NUM>) as well as ventilation means (<NUM>). The first compartment (110a) is adapted to house the generator set (<NUM>). The second compartment (110b) is adapted to house the LPG tanks or reservoirs (<NUM>). Thus, the frame (<NUM>) of <FIG> is a single indivisible frame that forms two compartments (110a, 11b): one for the generator set (<NUM>), that is, for motorization and electricity generation, and another for LPG tanks or reservoirs (<NUM>).

Additionally, the frame (<NUM>) includes bulkhead fittings for fuel lines, sensors and electronics. The bulkhead fittings and flexible pipes prevent vibrations caused by the operation of the generator set. In addition, the electric generator (<NUM>) can comprise two gas detectors per compartment (110a, 110b) to speed up the detection of potential leaks.

In addition, the frame (<NUM>) includes openings at the bottom of the frame (<NUM>) to vent potentially explosive accumulations inside the bodywork.

The electric generator (<NUM>) comprises a liquid-phase feed gas train (<NUM>) which is shown in <FIG> and which connects the three LPG tanks or reservoirs (<NUM>) of the electric generator (<NUM>) to the generator set (<NUM>) for the supply of LPG to the generator set (<NUM>). The liquid-phase feed gas train (<NUM>) for feeding the generator set (<NUM>) with LPG gas stored in the LPG tanks may include a manual valve, a particulate filter, a primary pressure regulator, a solenoid valve, a vaporizer, a low pressure switch and pressure gauges for the inlet and outlet of the gas train (<NUM>).

The three LPG tanks or reservoirs (<NUM>) established in the second compartment (110b) are independently isolated from the generator set (<NUM>) and from the necessary pipes and elements by means of a separation partition or barrier (<NUM>) that may comprise rock wool.

Also seen is a second gas-phase feed gas train <NUM> shown in <FIG> and <FIG> which is established in frame compartment 110a. The second gas-phase feed gas train (<NUM>) connects an external gas source to the generator set (<NUM>) for the supply of LPG or NG (Natural Gas) to the generator set (<NUM>).

The gas-phase feed gas train (<NUM>) for the external supply of the generator set (<NUM>) with LPG or NG gas may include a manual valve, a particulate filter, a primary pressure regulator, a double solenoid valve, a low and high pressure switch and pressure gauges for the inlet and outlet of the gas train (<NUM>).

To manage these three possibilities of fuel supply to the generator, there is an optional selector on the control panel with three positions depending on the option chosen: supply from internal LPG tanks in liquid phase, external supply of LPG in gaseous phase or external supply in gaseous phase of NG.

With regard to the thermal management of the LPG tanks or reservoirs (<NUM>), they are isolated, thus avoiding excessive heating of the reservoirs. <FIG> shows the installation of the LPG tanks or reservoirs (<NUM>) in the lower part of the generator set (<NUM>), in the part farthest from the main heat sources. Two critical points in heat generation are identified: Peaks of maximum power requirements continued over time, and after stopping the generator set engine, at which time the cooling system stops working and heat continues to be emitted from the hot spots of the system. Thus, to increase the thermal insulation between the compartments (110a, 110b), the separation partition or barrier (<NUM>) of the frame (<NUM>) shown in <FIG> comprises rock wool between the first compartment (110a) and second compartment (110b) of the frame (<NUM>).

The LPG tanks or reservoirs (<NUM>) have been isolated in the second compartment (110b) of the frame (<NUM>) and are independent of the generator set (<NUM>) established in the first compartment (110a) of the frame (<NUM>). The first and second compartments (110a, 110b) comprise direct outlets to the outside for possible gas leaks.

The first and second compartments (110a, 110b) comprise gas sensors. The compartment (110b) comprises passive ventilation for the LPG tanks or reservoirs (<NUM>) directly with the outside and ducts for the overpressure valves that expel the gas directly to the outside of the frame (110b).

In another preferred embodiment, the frame (<NUM>) comprises a subframe between the two compartments (110a, 110b) where the generator set (<NUM>) and the LPG tanks or reservoirs (<NUM>) are located, replacing the partition with rock wool. This subframe allows greater insulation than the separation partition or barrier (<NUM>) with rock wool in the event of an increase in the power of the electric generator (<NUM>) from <NUM> kVA to <NUM> kVA in a second preferred embodiment.

Claim 1:
An electric generator (<NUM>) operating on liquefied petroleum gas, LPG, comprising:
a frame (<NUM>) comprising a first compartment (110a) and a second compartment (110b), and
a generator set (<NUM>) driven by LPG established in the first compartment (110a), and
wherein the electric generator (<NUM>) comprises at least one LPG tank (<NUM>) established in the second compartment (110b); and
a first liquid-phase feed gas train (<NUM>) connecting the at least one LPG tank (<NUM>) to the generator set (<NUM>) for supplying LPG to the generator set (<NUM>), and
characterized by a first gas leak sensor in the first compartment (110a) of the frame (<NUM>) and a second gas leak sensor in the second compartment (110b) of the frame (<NUM>).