HEATING SYSTEM FOR VEHICLES

Abstract: The invention relates to a heating system for vehicles, particularly vehicles with air-cooled engines, and aims at exploiting heat from the exhaust gases of the vehicle for the heating of a space in the vehicle. The system has a heat absorber (3) which is disposed around the exhaust gas pipe of the vehicle, and a heat emitter (6) which is disposed in the space to be heated. The heat absorber and the heat emitter are interconnected by means of a pipe circuit (8, 8') for transporting heat-carrying liquid (7), a collecting vessel (9) and a liquid transporting means (10) being inserted in said pipe circuit. The collecting vessel is inserted in the pipe circuit (8) between the outlet (2) of the heat absorber (3) and the inlet (4) of the heat emitter and disposed on a lower level than the heat absorber, whereby the liquid (7) by gravity will flow into the collecting vessel in order, when the system is inoperative, to empty at least the heat absorber (3) of liquid.

Description: 1 The present invention relates to a heating system for vehicles, particularly vehicles with air-cooled en¬ gines / said system having a heat absorber equipped with an inlet and an outlet for absorption of heat from the exhaust gases of the engine, a heat emitter equipped with an inlet and an outlet which are connected to the inlet and outlet, respectively, of the heat absorber by means of a pipe circuit for transporting heat-carrying liquid, said heat absorber being adapted to deliver heat to a space to be heated, a collecting vessel connected to the heat absorber, and a liquid transporting means inserted in the pipe circuit. The object of the present invention is to exploit the exhaust gases of a motor vehicle for heating a space of the vehicle, for example the driver's cab. This object is achieved by means of the heating system according to the invention which is characterized in that the collecting vessel is connected in the pipe circuit between the outlet of the heat absorber and the inlet of the heat emitter and disposed on a lower level than the heat absorber, whereby the liquid by gravity can flow down into the collecting vessel in order, when the system is inoperative, to empty at least the heat absorber of liquid. An embodiment of the invention will be described in greater detail below, with reference to the accompanying drawing in which a heating system is diagrammatically shown. The heating system according to the invention com- prises two main components, namely a heat absorber 3 for absorption of heat from the exhaust gases of a vehicle engine, and a heat emitter 6 for delivering heat to a space to be heated. The heat absorber and the heat emitter each have one inlet 1 and 4, respectively, and one outlet 2 and 5, respectively, the outlet 2 of .the heat absorber being connected to the inlet 4 of the heat emitter via a first conduit 8 and the outlet 5 of the heat emitter being connected with the inlet 1 of the heat absorber via a second conduit 8' . The heat absorber 3 is in the form of a can which surrounds part of the exhaust gas- pipe of the vehicle. The part of the exhaust gas pipe " which is surrounded by the can is shaped such that its heat emitting surface is as large as possible, for example by the pipe being cor¬ rugated or having some type of heat emitting fins. The heat emitter can be of any conventional type whatever that is suitable in the connection contemplated and preferably is combined with a fan which is adapted to move the heat emitted by the heat emitter into the space to be heated. The heat from the heat absorber is transferred to the heat emitter by a heat-carrying liquid 1. for example water or a water glycol mixture which is transported in the conduits 8 and 8 1 by a circulation pump 10 inter- •posed in the first conduit 8. The heated liquid is caus¬ ed to flow from the outlet 2 of the heat absorber 3 to the inlet 4 of the heat emitter 6, where it gives off its heat. The cooled liquid in the heat emitter is transport- ed from the outlet 5 of the heat emitter to the inlet 1 of the heat absorber via the second conduit 8' . A constriction 13 of somewhat smaller cross-sectiona area than what corresponds to the pumping capacity of the circulation pump 10 is provided in the outlet of the heat absorber, and the heat absorber is therefore con¬ stantly filled with liquid 7 when operating with maximum heat emission, which will be described in greater detail below."With this constriction 13 it is thus possible to regulate the time during which the liquid shall be con- tained in the heat absorber. A collecting vessel 9 is inserted in the first con¬ duit 8 between the constriction 13 and the circulation OMPI pump 10. The collecting vessel 9 has an opening 14 at the upper end for communication with ambient air and such a volume that a free liquid surface and thus normal pressure is constantly maintained in the vessel. The collecting vessel is disposed on a lower level than the heat absorber such that the liquid in the heat absorber can flow down into the collecting vessel by gravity. A shunt valve, preferably a three-way valve 11, is connected in the first conduit 8 between the inlet 4 of the heat emitter 6 and the circulation pump 10. A shunt line 12 is connected between a shunt outlet 15 of the •shunt valve and the collecting vessel. The amount of liquid flowing to the heat emitter 6 can be controlled by means of the shunt valve and the shunt line. The shunt valve 11 is connected to heat control means (not shown) in the space to be heated. The circulation pump 10 is • also connected to said heat control means, and the pump can be made inoperative when the control means is closed, and operative when the control means is set for heat emission. When the heat control means is set for maximum heat the shunt valve 11 is adjusted in such a way that all liquid 7 flows through the valve to the inlet 4 of the heat emitter. After heat emission the liquid is pumped to the heat absorber 3 via the second conduit 8' . The pumping capacity of the pump 10 being slightly higher than what corresponds to the cross-sectional area of the constriction 13 the heat absorber will be filled complete¬ ly. In order that there shall not be created any pres- sure above atmospheric in the system when the heat absorber is entirely filled, the circulation pump 10 is of such a design that the liquid can stream in rearward direction into the collecting vessel when a predetermined pressure is established in the first conduit 8 between the pump 10 and the shunt valve 11. From the heat absorber the liquάd flows by gravity down into the collecting vessel and continues to the pump. _OMPI_ When the heat control means is set for a lower heat emission the position of the shunt valve 11 is changed in such a way that a certain proportion of the liquid is pumped from the pump via the shunt line 12 direct to the collecting vessel 9. The amount of liquid that is pumped via the shunt line 12 is dependent upon the setting of the heat control means. By reduced supply of liquid to the heat emitter the heat emission to the space to be heated is diminished. An infinitely variable heat control is thus achieved. When a lower amount of heat is supplied to the heat emitter the heat supply to the heat absorber 3 is reduced. The constriction 13 having the same cross- sectional area regardless of the liquid supply to the heat absorber the liquid level in said absorber.will sink.. At the same time the heat absorbing surface in the heat ab- sorber 3 is diminished, which reduces the risk that the liquid in the heat absorber will boil. When the heat control means is closed the pump is made inoperative, the heat absorber being emptied in that the liquid flows down into the collecting vessel 9. •

Claims: CLAIMS 1. A heating system for vehicles, particularly ve¬ hicles with air-cooled engines, comprising a heat ab¬ sorber (3) equipped with an inlet (1) and an outlet (2) for absorption of heat from the exhaust gases of the en- gine, a heat emitter (6) equipped with an inlet (4) and an outlet (5) which are connected to the inlet (1) and outlet (2) of the heat absorber by means of a pipe cir¬ cuit (8, 8') for transporting heat-carrying liquid (7), said heat emitter being adapted to emit heat to a space to be heated, a collecting vessel (9) connected to the heat absorber (3) and liquid transporting means (10) in¬ serted in the pipe circuit, wherein the collecting ves¬ sel (9) is inserted in the pipe circuit (8) between the outlet (2) of the heat absorber (3) and the inlet (4) of the heat emitter (6) and disposed on a lower level than the heat absorber, whereby the liquid by gravity will flow into the collecting vessel in order, when the system is inoperative, to empty at least the heat ab¬ sorber (3) of liquid. 2. A system as claimed in claim X, wherein the liquid transporting means (10) is inserted in the pipe cir¬ cuit between the collecting vessel (9) and the heat emit¬ ter (6) and disposed on a lower level than the collect¬ ing vessel. OMPI

Inventors: SELLIN G
Applicants: BLACKSTONE TERMFROST AB, SELLIN G, BLACKSTONE TERMOFROST AB
Application year: 1979
Main classification: B60H1
IPC codes: B60H1