GB2383839A

GB2383839A - A liquified gaseous fuel powered vehicle and air conditioner.

Info

Publication number: GB2383839A
Application number: GB0200125A
Authority: GB
Inventors: Neville Tubb
Original assignee: Individual
Current assignee: Individual
Priority date: 2002-01-04
Filing date: 2002-01-04
Publication date: 2003-07-09
Also published as: GB0200125D0

Abstract

A vehicle powered by a liquified gaseous fuel in which the said fuel is used as the fluid medium of a heat exchanger 5 for the heat exchange between the said fuel and the internal air of the vehicle, where by the heat is transferred to the said fuel. Preferably the fuel is a compressed gas or a compressed natural gas. The vehicle may include a liquified gaseous fuel supply line 1 with a solenoid valve 2 and expansion valve 4 disposed there in before the heat exchanger. The solenoid valve may be controlled by a thermostat 3 which monitors the internal air temperature 8 of the vehicle. Preferably there is a pressure drop from seven bar to one bar across the expansion valve which causes the liquified gas to vaporise cool. Cold vapour and liquified gas flow into the heat exchanger and the internal air is preferably blown or fanned over the heat exchanger. As the heat is absorbed from the internal air this results in a superheated vapour exiting the heat exchanger which may be controlled by a pressure regulating valve 6 to a pressure of 1 bar, before returning to a return mixing line 7. The vehicle may have more than one internal compartment which may need air conditioning or refrigerating. Additional heat exchanges and pumps maybe utilised to accommodate the other internal compartments. A pressure switch (14, fig.4) maybe used to control the solenoid valve. Preferably the heat exchanger is disposed within a eutectic beam which changes the liquified gas to a solid state at the desired temperature.

Description

A method of cooling the internal air of a vehicle.

This invention relates to transport refrigeration and transport air conditioning.

Transport refrigeration and transport air conditioning are well known.

Typical systems use a standard vapour compression cycle using the phase change of a refrigerant to move the heat from inside the vehicle to outside the vehicle. The vehicle may have several compartments each at different temperatures. These systems are mainly powered in two ways. Either by a prime mover such as a diesel engine or a mechanical power "take off" from the vehicle's engine.

These systems require large capital investment and frequent maintenance. Further they produce significant levels of carbon fuel and noise pollution.

The present invention relates to liquefied gaseous fuel powered vehicles and their internal cooling requirements for passengers, perishable foodstuffs, and other cargo that require temperature control, in single or multiple temperature compartment format. The improvement relates to the reduction of : co2 and noise pollution, capital cost and life cost when compared with a conventional transport system.

According to the present invention there is provided a heat exchanger having means for effecting heat exchange between the liquefied gaseous fuel and the internal air of the vehicle whereby heat is removed from the internal air of the vehicle and said heat is transferred to the liquefied gaseous fuel.

A specific embodiment of the invention will now be described by way of examples with reference to the accompanying drawings in which :- Figure 1 shows one method of transferring heat between the liquefied gaseous fuel and the internal air of the vehicle for one compartment.

Line 1 is the supply of liquefied gaseous fuel to solenoid valve 2, which is controlled by thermostat 3. If the vehicle internal air temperature 8 is above the thermostat set point valve 2 opens. This supplies the expansion valve with liquefied gaseous fuel. The pressure drop across the expansion valve 4 from approximately 7 bar (g) to 1 bar (g) causes the some of the liquid to vaporise cooling the remaining liquid to approximately- 35 C.

Cold vapour and liquid flow into heat exchanger 5. Air passes over 5 by means of fan 9.

Air with a greater temperature then the vapour and liquid mixture in the heat exchanger 5 will further vapourise the mixture, thereby absorbing heat from the air. The expansion valve will control the amount of liquid present to ensure that the vapour is superheated at the exit of heat exchanger 5. Valve 6 is a pressure regulating valve which ensures the superheated vapour is presented to line 7 at the correct pressure (approximately 1 bar (g))

to mix with other vapour for the internal combustion engine. When the air is at the required temperature thermostat 3 closes valve 2.

Some vehicles have more then one compartment and temperature requirement.

Additional feeds from line 1 facilitate multiple compartment temperature control. Figure 2 shows one additional compartment, more feeds from line 1 facilitate more compartments.

Figure 3 shows another arrangement of figure I where a liquid moved by a pump 10 transfers the heat to heat exchanger 5 from heat exchanger 12 which absorbs heat from the internal air of the vehicle 8 by means of fan 9. Multiple temperature control can be achieved by introduction of more heat exchangers 12 into the coolant circuit.

Figure 4 shows another arrangement of figure 1 where the liquid and vapour mixture are expanded after the expansion valve 4 in a heat exchanger inside a eutectic beam, which changes the liquid to a solid at the desired temperature. Solenoid valve 4 is controlled by pressure switch 14. The eutectic absorbs heat from the internal air of the vehicle by changing back to a liquid.

Claims

CLAIMS 1. A vehicle with an internal combustion engine fuelled with a liquefied gaseous fuel having means for effecting heat exchange between the liquefied gaseous fuel and the internal air of the vehicle whereby heat is removed from the internal air of the vehicle and said heat is transferred to the liquefied gaseous fuel.
2. As in claiml the liquefied gaseous fuel delivered to the heat exchanger comprising means for vaporising said liquid.
3. As in claiml having means to deliver heat from the internal air of the vehicle to the said heat exchanger.
4. As in claim 3 means to control amount of heat removed from the internal air of the vehicle to said heat exchanger thereby control temperature of the internal air of the vehicle.
5. As in claim 3 having means for effecting heat exchange between the, vehicle fabric heat gains, passengers, and product heat load, and the internal air of the vehicle.
6. As in claim 1 using the expansion of gaseous fuel in a vehicle powered by compressed gas or compressed natural gas.