GB2182134A - Heating, cooling and ventilating vehicles - Google Patents

Abstract

An arrangement for controlling the interior temperature of a passenger transit vehicle 10 of the kind driven by a liquid-cooled engine and for ventilating the interior of the vehicle, comprises a primary closed system of conduits positioned near the vehicle floor and which conducts hot engine coolant from the engine to the passenger space and the driver's space of the vehicle. Arranged above the vehicle windows is at least one further closed conduit system which is embraced along at least the greater part of its length by ducting 40. The ducting communicates with fresh-air intakes 14 and is constructed to direct the incoming air into contact with the hot water conduits and to supply this air via openings 37 into the passenger space and/or the driver's space of the vehicle. In hot weather (see left hand side of Figure 2) cold liquid is supplied to the conduits in the ducting 40 and the cooled air is also supplied to the vehicle through outlets in further ducting 41. <IMAGE>

Description

SPECIFICATION An arrangement in passenger transit vehicles for controlling the interior temperature and ventilation thereof The present invention relates to an arrangement in passengertransitvehiclesforcontrollingtheinterior temperature and ventilation thereof, in accordance with the preamble of Claim 1.

A passengertransit vehicle, for example an intercity or interurban bus or coach, is normally provided with internal heating means in the form of a flanged radiatorelementwhich extends along the bottom of the vehicle passenger-area in the longitudinal direction of the vehicle on both sides thereof, and through which heated engine-coolant is forced into a closed conduit circuit embodying the radiator. The heat carried by the hot engine coolant is transmitted, in a conventional manner, to the radiator fins orflanges, extending from the conduit along which the heated coolant is conducted and dispersed to the seating area ofthe vehicle. During colder periods of the year, the temperature of the engine coolant, e.g. water, is often increased, so as to raise the air temperature of the passenger area, this being effected with the aid of a thermostat for example.

Such conventional heat exchange devices belong to the present art, and are not ableperseto assure the individual comfort of the passengers. Cold floors, windows and walls attract most ofthe heat given off bytheradiators.Thewarmairgenerated normally warms solely one side of a seated passenger, leaving the other side of the passenger cold. Conversally, passengers may find their environment equally as uncomfortable when surrounding surfaces are heated to a temperature higherthan the temperature of hislherskin, e.g. through the rays ofthe sun in the hotteryear periods. In cases such as these, the atmospheric air distributed to the vehicle interior is not able to improve the comfort of the passengers to any appreciable extent.

When the skin temperature of normal passengers is in equilibrium with the temperature ofthesur- rounding surfaces, however, the climate is felt to be comfortable.

The object of the present invention is to provide a simple, but reliable arrangement capable of creating highly uniform temperature conditions throughout the whole length of the vehicle, irrespective ofthe time of year, at lower installation costs and with a satisfactory result.

This object is realized by the basic concept of the invention setforth in the preamble of Claim 1.

Further developments of the invention are set forth in the depending claims.

The invention will now be described in more detail with reference to an exemplifying, non-limiting emb odiment thereof illustrated in the accompanying drawings, in which Figure 1 illustrates a passengertransit vehicle in the form of a coach, fitted with a heating and ventilating system according to the invention; Figure2 is a cross-sectional view ofthe coach illustrated in Figure 1; Figure3 is a schematic illustration of the heating and ventilating system according to the invention; Figure 4 is a sectional view of part of the vehicle illustrated in Figures 1 and 2, and illustrates schemat ically a preferred embodiment ofthe air ducts; and FigureS is a sideview ofthe flanged radiator.

Acoach 10 intendedforpassengertransitincor- porates conventionally a passenger space 11 and a driver's space 12. Although not shown, the coach is also provided with entrance and exit doors in one side ofthe coach, of which the entrance is normally located to the right ofthe driverwhen seen inthefor- ward direction of the coach (when driven on the right-hand side of the road). The passenger space is provided with at least one exit, most often two. An air-evacuation valve 45 is provided in the lower region of the coach, adjacent the forward entry door, for a purpose hereinafter more apparent.

The vehicle or coach 10 is provided with a plurality offresh-airintakesl3, 14,which are arranged suitably on the roof of the coach 10, laterally of the geometric centre-line ofthe coach. Figure 1 illustrates two such fresh-air intakes 13,14 in mutually spaced relationship, namely a fresh-air intake 13which co- acts with the arrangement according to the invention in creating a good working environmentforthe coach driver, i.e. a comfortable environment in the driver's space 12, and afresh-air intake l4which, in a similarfashion, is instrumental in supplying air toe passenger space 11. As shown in Figure 2, the passenger space 11 is served by two fresh-air intakes 14 in the illustrated, selected embodiment.Preferably, each of the fresh-air intakes 13, 14 is provided with a respective fan means (not shown) of known construction. The fresh-air intakes 13, ofthe illustra- ted embodiments are constructed to forcibly guide atmospheric air, via a horizontal channel 13', 14', to a lower, horizontal conduit 13", 14" which communicate with respective inlets in the driver's space and the passenger space. Dust, pollen and other contaminants are extracted from the incoming atmospheric airwith the aid of conventional filters, indicated at 15, so as to purify the air to the best possible extent priorto its entry into the coach.

The mannerin which the atmospheric airistreated will be explained hereinafter.

The construction ofthe heating and ventilation system according to the invention and the manner in which the system operates will be described here inafter with reference to Figure 3, which illustrates two identical systems according to the invention, one for the driver's space and the other for the passenger space.

Conventionally,thevehicle 10 hasa liqiud-cooled engine 5, from which heated coolant is pumped into the conduit 16 of a primaryclosedcircuitorsystem, in the direction of arrow A, which conduit, in the case of a coach or bus, is located at a shortdistancefrom the planeofthefloor. The conduit 16 extends in the longitudinal direction ofthe vehicle in substantially the same manner as that illustrated, i.e. along one side ofthe vehicle, while a pump (not shown) is arranged to return the heated engine coolant to the coolant chamber ofthe engine through the iilustrated return conduit 16'.The conduits 16,16' ofthe primary conduit circuit are connected in a conventional mannerto flange-type heat exchangers, or to some other suitable kind of heat exchanges, to produce convection heat and hot-air heat in the interior ofthe vehicle.

Thistype of heat distribution is normally all that is provided in collective passenger vehicles, and particularly in intercity or interurban passangertransit vehicles.

With reference to the system shown to the left of Figure 3, the right-hand system being identical to the left-hand system, it is now suggested in accordance with the invention that the known primary heating circuit is replaced with, or alternatively combined with an arrangement in which the engine coolant is distributed in a controlled and regulated fashion to a pipe 17which incorporates a pump 18 operative to pump heated coolantto an upwardly extending conduit 19 via a short connecting pipe 17', the conduit 19 bending at 20" to extend horizontally in the longitudinal direction ofthe vehicle, substantially above the upper edge of respective windows, as shown by the conduit 20.The conduit may extend along the whole or part ofthe longitudinal extension ofthe vehicle interior along one side thereof, and then turn to extend across the vehiclar interior, and finally be turned so asto extend along the other side ofthevehicle, in a mannersimilarto its extension along the firstmentioned side of the vehicle. The conduit is then bent down at 20' and is rejoined with the conduit 19 via a transverse pipe 21, the heated coolant being conducted with the aid ofthe pump 18.

The illustrated flow circuit 19,20,20', 21 is thus normally closed, and heat losses will be experienced, of course, in the liquid flowing therein. In orderto enable these losses two be compensated for and to maintainthetemperatureofthe liquid ata pre- determined level, the conduit21 has arranged therein a temperature sensor ortemperatureresponsive means 22 which when necessary, i.e.

when the temperature of the liquid falls beneath the aforesaid pre-determined value, causes a valve 23 to open, thereby enabling hot coolant to be pumped from the primary conduit 16, by means ofthe pump 18, to the upstanding conduit 19 and from there to the circuit 19,20,20', 21,untilthetemperature- responsive means 22 detects that a desired temperature has been reached and therewith causes the valve 23 to close.

To safeguard against malfunctioning of the pump 18, there is provided a pipe 17" which connects the pipe 17 with the pipe 17' downstream of the valve 23 and supplies the circuit 19,20,20', 21 with heated coolant from the primary circuit 16. A check valve 24 is arranged to ensure that coolant is notforced rearwardly along the transverse pipe 21.

As shown in Figure 3, the vertical pipe 20' extending down from the return side of the conduit 20 has incorporated at the bottom thereof a water-trap 25 for separating, air-bubblesfrom the liquid. The return conduit 16' of the primary circuit is connected to the pipe 21 ofthefurtherconduitsystem by means of a short branch or riser pipe 26.The riser pipe 26 is intended to function as a back-up de-aerating means, i.e. means for preventing air which escapes the trap 25andentersthepipe2l from being entrained bythe flowing liquid, back to the conduit 19, such air being instead removed from the pipe 21 via the riser pipe 26, and passed into the return pipe 16' of the primary circuit, where the air is treated in a manner known perseforming no part of the present invention.

The further closed circuit 19,20,20', 21 is connected to a cooling unit 27functioning in accordance with known principles, at some suitable location in the circuit, for example to the conduit 19. When required, for example during the summer months,the liquid can be cuased to flow through the cooling unit 27, which is incorporated in a branch pipe 28 connected to the conduit 19 at two mutually spaced locations therein. In addition hereto there is oncorporated upstream and downstream ofthe cooling unit 27 a respective valve 29 and 30, which can be operated from the driver's space, for example.

The flow circuit 20,20', 21 illustrated to the left of Figure 3 is intended to serve solely the passenger space of the vehicle. An identical further system of conduits or circuit referenced 31,32,33,34,35 is shown on the right ofthe Figure and is itended to serve solely the driver's space in the vehicle.

This latter circuit incorporates a water trap 25' sim ilarto the watertrap 25 of the previously described circuit. The conduits 20 and 32,33 of respective circuits for conducting the flowing liquid, i.e. the con duits extending in the longitudinal direction ofthe coach according to Figure 3 and transversally to the long axis of the vehicle in the driver's space and at the rear of the vehicle, have extending radially therefrom mutually adjacent, closely located, circularfins or flanges, forming thereby known flanged heating elements. Figure 5 illustrates one such known flanged heating element, or fin type heating-element, in which thefins orflanges extend at right anglestothe longitudinal axes of respective conduits.

Figure 4 illustrates an exemplifying embodiment which incorporates one such heating element, the heating element being mounted in the interior ofthe vehicle on a plane extending substantially level with the upper edges ofthe side windows and thewindscreen. Part of one side window Wis shown schema tically in Figure 4. The flanged heating elementis supported throughoutthe whole of its length buy a profiled section, which in the illustrated embodiment comprises two half-sections 36,36' which are screwed together and house the heating element therebetween. Each profiled section 36,36' informed so as to enclose a large area of the heating element, suitably 40 - 70% in a close or substantially close re- lationship. The undersurface of the profiled section presents an opening 37 which extends, preferably continuously,throughoutthewhole length ofthe vehicle, and also transversallythereof, at least in the driver's space, and one section-half 36 is provided with means 38 for attachment of the half-section to a bracket structure attached to the body of the vehicle.

Such attachment or suspension points are distributed throughoutthe vehicle and are arranged so to ensurethatthe heating elements are mounted in the position desired, the opening or mouth 37 provided in the profiled section 36,36' being inclined slightly towards the windows of the vehicle. In practice the opening or mouth 37 has the form of an elongated exit slotwhich faces downwardly, or obliquely downwardly towards the surface ofthe windows in the vehicle. A preferred angle between the surface of a window and the air stream is between about 15-25", suitably 20". The above description of the arrangement ofthe flanged heating element in the passenger space 11 also applies in all respects to the separate arrangement in the driver's space.

Thefresh-airducts 14"and 13" illustrated in Figure 1 communicate with a firstducting 40 (Figure 4) which in the Figure 4 embodiment is assumed to be made of a flexible material, for examplefabric- coated plastic, and which is connected with the profiled sections 36,36' along the length oftheflanged heating element 20. The ducting 40, made of said flexible material, is connected so close to respective heating elements as to form a pressure chamber, the prevailing pressure in which is considerably higher than that prevailing in the passenger space and the driver's space. The cross-sectional area ofthe ducting 40 is in given proportion with the length ofthe ducting and the width of the exit slot 37.Consequently, the relatively large quantity of air entering the ducting 40 will be forcibly guided down between the flanges or fins of the heating element 20 etc. along the whole of its length, these flanges extending at right angles to the longitudinal axis of the associated conduit. Thus, in wintertimethe incoming atmos phericairis heated by the heating elements and passes out through the opening or slot 37, from where it sweeps down over the inner surface ofthe vehicle windows, in both the passenger space and the driver's space. The particular construction ofthe ducting 40 and the manner in which it functions ensures that substantially the same volume ofair isdispersed along the two long sides of the passenger space.

Thus, in the illustrated embodiment, the heated air exiting through the elongated slot-like opening is brought into contactwith the heatgiven-offbythe primary heating circuit ofthe vehicle, through the conduit system 16, 16' (Figure 3). The relatively large quantity of air entering through the fresh-air intakes in the roof of the vehicle creates in the passenger space a slight but nevertheless desirable overpressure. The aforementioned air-evacuation valve 45 (Figure 1) is held constantly open during vehicle transit and as a result of the aforesaid overpressure air under pressure will constantly flowtowards said valve 45. The driver's space can therefore be said to form a subpressure zone.The direction of airflow is shown by arrows in Figures 1 and 2, i.e. from the rear towards the front, and the right-hand part of Figure 2 illustrates howthe combined system is utilized in wintertime, during periods of very cold or extremely cold weather, whereas the left-hand side of Figure 2 shows, by way of example, how the system is utilized during the summer months, this latter usage being described hereinafter.

In order to avoidthe "radiation" of cold, particularlywhen the aforesaid ducting 40 comprises fabric-coated plastics, a further duct 41 ,which serves to insulate the fabric coating, may be arranged so as to surround the ducting 40 along the side thereof remote from the body ofthevehicle and to form, atthe sametime, a separate air-transit passage communicating partly with the ducting 40 and partly with the central region of the vehicle interior, via nozzles 42 and/or a rearwardly located outlet 43 for example.

The further ducting 41, however, is intended for use mainly during the warm year period, and consequently means (not shown) are provided for closing and opening communication between the ducting 40 and the ducting 41 as necessary. In the autumn and spring both ductings can be used, the ducting 40 to transportwarm air and the ducting 41 to transport cold air.

The circuit 31-35 illustrated to the right of Figure3 is separate from the circuit 19-21 shown to the left of the Figure, but of identical construction, and is intended to serve solely the driver's space, as beforementioned. At least the conduits 32,33 of the circuit31-35 havetheform offlanged heating conduits which co-operate with guide and attachment means in the same manner as that described with reference to Figure 4. Thus an exit slot corresponding to the exit slot 37 is arranged to cause warm or cool airto flow down towards the side-windows of the driver's space, while a similarexitslot is arranged to cause air to flow down onto the inner surface of the wind- owscreen.

In the aforegoing the description has dealt mainly with creating pleasant conditions in the passenger compartment ofthe vehicle during cold periods of the year. During warmer periods ofthe year it may suffice solely to use the circuit 19-21, shown on the left of Figure 3, togetherwith the cooling unit 27, in order to provide a comfortable temperature in the passenger space. Means (not shown) for controlling the illustrated and described heating/cooling and ventilating system are conveniently provided at a location readily accessible to the driver of the vehicle.

The aforedescribed heating/cooling and ventilating circuit or circuits located on the same level as, or immediatelyabove,the upperedge of at leastthe greater part of the window-area of the vehicle can, under certain conditions, alone provide a pleasant climate within the vehicle interior, both for the pas sender and the driver. This will only apply, of course, in countries which experience a mild climate and where the differences in temperature between different periods oftheyearare not so noticeable.

In countries where prevailing weather conditions are similartothose ofthe Nordic countries, however, it is probable that it will be necessary to use the primary floor-mounted radiator system of the vehicle (as shown in Figure 2) in conjunction with the novel heating system according to the invention, the temperature of this primary standard system being controlled in the same manner as the conduit-circuits 1921 or31-33.

The systems according to the invention are constructed so that the liquid conducted therethrough need only be heated to a relatively lowtemperature, normally about 30"C, while still affording adequate heating. Forexample,whenthe liquidflowing through respective systems or circuits has a tem perature of about 30"C, the airflowing through re spective air slots 37 down into the passenger space and the driver's space will have a temperature of about 25"C, i.e. a temperature which imparts to the window surfaces the correct physiological temperature level to be in balance with the skin tem peratureofnormal passengers. Thedownwardlydir ected airflow, which loses some of its heat to the colder surfaces of respective windows, meets the uprising convection heat emitted bythefloor-mounted radiators, thus also keeping the floortemperature at a comfortable level. It can be mentioned by way of examplethatthetemperature of liquid flowing in the circuits 16,16', 19-21,31-34 in in wintershould be only slighter higherthan the skin temperature of a normal passenger, whereas in the summertime the system can be set to a temperature just below the mean temperature of the air outside the vehicle.

Although the vehicle referred to in the description has the form of a coach, it will be obvious thatthe invention can be installed in other types of vehicles.

Similarly the profiled sections or ducting can have a form differentto that illustrated and described.

Claims (15)

1. Atemperature-controlling and vehicle- ventilating arrangement for passenger transit vehicles (10) ofthe kind equipped with a liquidcooled engine (5) and a primary closed conduitcircuit (16, 16') which is operative to conduct hot coolant from the engine in orderto heatthe passenger space (11) and the driver's space (12) of the veh icle through the agency offlanged radiatorsorsim- ilar heat-emitting devices located in the proximity of the vehicle floor, wherein the arrangement also includes at least one further closed conduit-circuit (19 21 ) which is separate from and located above the primary circuit (16, 16') at a distance therefrom; wherein the at least one further conduit circuit is enclosed in a ducting system (40) adapted to receive atmosphericairfromexternally locatedfresh-airin- takes (13,14) provided herefor; and wherein the ducting is constructed in a mannerto direct airflowing therethrough and contacting the conduits (20) in the closed conduit-circuit (19-21) down into the passengerspace (11) and/orthe driver's space (12) ofthe vehicle.

2. An arrangement according to Claim 1, wherein the at least one further closed conduit circuit (19-21 ) is located on a level with or adjacent to the upper edges of the windows of the vehicle; and wherein the ducting (40) which houses the conduit circu it is constructed to direct air flowing therethrough downwardlyto the vehicle passenger space and/orthe driver's space via the surfaces of the windows located beneath the circuit

3. An a rra n gement accordi ng to Claim 1 orClaim 2, wherein the at least one further conduit-circuit (1921) is connected in series, or in parallel, with a cooling unit(27).

4. An arrangement according to any of Claims 13, wherein means (22) are provided for controlling the temperature ofthe liquid in the at least one furtherconduit-circuit (19-21); and wherein the at least one further conduit-circuit is connected to the primary conduit-circuit (16,16') in a manner to enable heated coolant to be passed automatically from the primary circuitto thefurthercircuit (19-21) as required.

5. An arrangement according to any of Claims 1 4, wherein the arrangement incorporates at least one further closed conduit-circuit (19-21) with associated ducting system effective to control the climate ofthe passenger space, and at least one further closed conduit circuit (31-34) with associated ducting system ef festive to control the climate ofthe driver's space.

6. An arrangement according to any of the preceding Claims, wherein the at least one further conduit circuit, or both ofthe further circuits, together with associated ducting (40) extends, or extend, along both sides of the passengerspace; and wherein conduits of each said at least one further circuit are provided with radially extending flanges or fins, to form flanged heating elements.

7. An arrangement according to Claim 6, wherein each flanged heating element is arranged to co-act with means (36,36', 37) for guiding the inflowing atmospheric airforcibly between and in contact with the flanges ofthe element and overthesurfaces of underlying windows in the passenger space.

8. An arrangement according to Claim 7, wherein the means forforcibly guiding air between the flanges of each flanged element comprises a profiled section (36,36') which forms part of the ducting (40) and surroundstheflanged element in relatively close relationship therewith and which profiled section presents obliquely downwardly extending side port iona which are spaced aparttoform a slot-like open- ing (37) through which air flowing through the ducting (40) and the profiled section is directed downwards into the vehicle interior; and wherein the slot -like opening extends at least along the greater part of the length of the flanged element, so as to distribute air uniformlythroughoutthe entire length of the vehicle.

9. An arrangement according to Claim 7 and Claim 8, wherein the ducting (40) is made of a flexible material; wherein the ducting is at least partially sur- rounded by an auxiliary ducting (41); and wherein means are provided for opening and closing communication between the ducting and the auxiliary ducting and for connection with the passenger space of the vehicle.

10. An arrangement according to Claim 8, wherein the slot-like opening (37) is directed towards adjacent window surfaces at a given angle thereto, preferably 15-20".

11. An arrangement according to any of the preceding Claims, wherein the ducting (40) is so arranged as to form a pressure chamber, which ensures that the incoming atmospheric air is distributed uniformly along the whole length ofthe ducting.

12. An arrangement according to one or more of the preceding Claims, wherein an air-evacuation valve (45) capable of being opened to the ambient surroundings is arranged forwardly of the passenger space and beneath the driver's space; and wherein means are provided for holding the valve open when the vehicle is in transit, so as to form in the driver's space a region of low pressure, such that air exiting through the opening (37) into the passenger space is continuously drawn therefrom out through the valve.

13. An arrangement according to any of the preceding Claimsforuse intimes of lowoutsidetem- peratures, wherein means are provided for maintaining the temperature of the liquid passing through the conduits ofthe at least one further circuit or circuits at a level which differs only slightlyfrom the skin temperature of an average passenger.

14. An arrangement according to anyoneof Claims 1-12foruse in times of relatively high outside temperatures, wherein means are provided for disconnecting theflowofenginecoolanttothe primary circuit and the at least one further circuit or circuits, such that the temperature ofthe air entering the interior ofthe vehicle through the ducting (40) is lower than the mean outside temperature.

15. Atemperature-controllingandvehicle- ventilating arrangement substantially as hereinbefore described with reference to, and as illustrated in the accompanying drawings.