WO2014033328A1

WO2014033328A1 - A heating system

Info

Publication number: WO2014033328A1
Application number: PCT/EP2013/068200
Authority: WO
Inventors: Denis O'dwyer
Original assignee: Denis O'dwyer
Priority date: 2012-09-03
Filing date: 2013-09-03
Publication date: 2014-03-06
Also published as: IES86173B2; IES20120381A2

Abstract

A heating system comprises a liquid-filled radiator 10 whose contained liquid is heated by an electrically powered positive temperature coefficient (PTC) heating element 16. The electric power may be derived from a battery 24 or solar energy 22.

Description

A Heating System

Field of the invention

This invention relates to a heating system, and in particular, but not exclusively, to a system that can be adapted to control automotive vehicle heating / climate control systems but also can be adapted to control domestic, commercial or industrial buildings heating systems and domestic hot water systems in addition to being used as a preheater or temperature regulator for vehicle subsystems in order to regulate the temperature of one or more working fluids such as lubricants, coolants and the like.

Background of the invention

Automotive vehicles and especially vehicles such as ambulances and specialized vehicles require for passenger and patient care to have the climate (interior temperature) to be at a comfortable level at all times. This necessitates either using a diesel or gasoline powered heater which necessitates having to run the engine to operate such heater systems efficiently and keep batteries at a certain voltage. Some conventional systems in a vehicle use a water heater which is connected into the cooling (coolant) system of the vehicle, but this still needs to have the vehicle's engine running and also has a delay period where it takes the vehicle's engine some time to heat all the coolant (added coolant due to added lengths of hosing / pipe work and heater matrix) to a sufficient level for heating of the vehicle's compartments sufficiently. Sizeable fuel consumption and emissions is typical of these conventional heating systems.

With vehicles operated in extreme climates, in particular low temperature climates found in areas such as the Artie, Antarctic, Scandinavia, Canada and Russia, there can be numerous complications due to the reduced temperatures, which can freeze or significantly increase the viscosity of various working fluids of the vehicle such as oil or other lubricants, radiator coolant, etc. rendering the vehicle inoperative. As a result it is often necessary to fit what is referred to as a "block heater" (an engine block heater) to the vehicle, which is conventionally powered from a mains supply, although block heaters do exist that are powered from the vehicle fuel supply, such as petrol or diesel. These block heaters are conventionally located in line with the radiator or heater supply pipes in order to heat the working fluid, which will then heat the engine block in order to allow the vehicle to start and operate as normal. In the absence of such a block heater it may be necessary to continuously run the vehicle engine to prevent the working fluids from freezing. Obviously this can be a very costly undertaking, in particular in connection with commercial or larger vehicles having high capacity engines with significant fuel consumption. It is therefore an object of the present invention to provide a heating system, in particular but not exclusively for use in automotive vehicles / emergency service vehicles, which avoids or mitigates the above-mentioned problems.

Summary of the invention

According to a first aspect of the present invention there is provided a heating system comprising a liquid-filled radiator whose contained liquid is heated by an electrically powered positive temperature coefficient (PTC) heating element.

Unlike conventional heating systems the invention does not require the use of hydrocarbon fuel such as oil, gas, diesel or solid fuels as is commonly used today. Its PTC heating element can be powered by a solar panel or by one or a combination of batteries and as the heating element heats up its power consumption reduces.

Preferably, the electric power is at least partially derived from at least one of a battery, a mains supply and/or solar energy.

Preferably, the heated liquid is circulated in the radiator by a pump.

Preferably, the heated liquid is circulated in the radiator by convection. Preferably, the radiator is selectively connectable to a separate source of heated fluid.

Preferably, the heating system includes an electric ian providing forced convection of the radiator.

Preferably, there are a plurality of stacked liquid-filled radiators through which the heated fluid circulates.

Preferably, the heating system is mounted in an engine-powered vehicle, wherein the electric power is at least partially derived from a battery which is recharged by a vehicle alternator when the vehicle's engine is running.

According to a second aspect of the present invention there is provided a vehicle comprising heating system according to the first aspect of the invention, in which the temperature of one working fluids of the vehicle can be regulated by the heating system. Preferably, the heating element is mounted in line with a radiator of the vehicle, in order to permit the working fluid within the radiator to be heated prior to the engine being started.

As used herein, the term "PTC" heating element is intended to mean a positive temperature coefficient heating element, or one in which the heating element experiences an increase in electrical resistance as the temperature increases, thereby effectively providing a self regulation heating element. PTC heating elements conventionally utilise a ceramic based material whose electrical resistance increase dramatically beyond a particular temperature, known as the "curie temperature", such that above this temperature effectively no current will be able to flow through the element, thereby regulating the temperature of the element.

Brief description of the drawings Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a schematic diagram of a first embodiment of the invention. Figures 2 and 3 show modifications of the system of Figure 1.

Figure 4 is a schematic diagram of a second embodiment of the invention. Figure 5 is a schematic diagram of a third embodiment of the invention.

Detailed description of the drawings

Referring to Figure 1 , the embodiment of heating system there shown comprises a conventional domestic hot water radiator 10 with inlet and outlet valves 12a, 12b respectively. The input and output valves are connected via a 12 240 volt ac/dc circulating pump 14 and a 12 240 volt ac/dc PTC ceramic heater element 16 with adjustable temperature sensing, housed in a chamber 18. The radiator 10 optionally includes an adjustable external temperature sensor 20. By adjustable temperature sensing we mean using a sensor (not shown) in the manner of a thermostat to monitor the temperature of the PTC element 16, or the coolant (not shown) that surrounds the element 16, and when the temperature rises above, or falls below, a pre-determined adjustable threshold level switching off, or on, the electrical supply to the element 16 to maintain the temperature at about the threshold level. It is also possible to monitor the current flow to the PTC element 16 and as the element's electrical load decreases substantially as the element 16 reaches the "curie" temperature this can be used to control switching on and or off the electrical supply to the element 16 at a pre-determined electrical load / device temperature.

The radiator 10 optionally includes an adjustable external temperature sensor 20 whose primary function is to control the switching of the fan when a fan assisted system is used (Figures 4 and 5). It could also be used to turn on or off the power supply to the PTC element 16 when the temperature of the working fluid of the radiator 10 reaches a pre-determined level. The temperature sensor 20 is positioned at a low level to help insure that the working fluid of the radiator 10 has reached the desired temperature.

The PTC heater element 16 is electrically powered, and preferably by one or more solar panels 22, which also charge a 12 or 24 volt battery pack 24. The battery pack 24 provides reserve power at night and also supplements the solar power during the day. Although not shown, the pump 14 is also powered by the battery pack 24. Alternatively, the circulating pump 14 and PTC heater element 16 can be powered from a 1 10-240 volt ac mains.

The system shown in Figure 1 is a closed system in which water as the working fluid is heated by the PTC heater element 16 and circulated in the radiator 10 by the pump 14. It will of course be appreciated that any other suitable arrangement may be employed, for example where the radiation uses a different working fluid, the solar panel 22 is replaced by a suitable functional alternative, and the function of the pump 14 is carried out by some other suitable component (not shown). Figure 2 shows a modification of the system of Figure 1. In this case the pump 14 is omitted and the PTC heater element 16 is connected between the top and bottom of the radiator so that hot water is circulated in the radiator 10 by convection, being heater within the PTC heater element 16 and rising to enter the top of the radiator 10, while cooler water or other working fluid is drawn into the lower end of the element 16 from the bottom of the radiator 10. The solar/battery power supply is not shown in Figure 2 but may of course be employed, as may any other suitable arrangement of power supply.

Figure 3 shows that how the system of Figure 1 can be connected into a conventional boiler system by flow and return pipes 26a, 26b incorporating on/off valves 27. Again, the solar/battery power supply is not shown.

Figure 4 shows an industrial application of the invention in which a number of standard radiators 10 or comparable heat exchangers are stacked on their side and connected so that the hot water heated by the PTC element 16 circulates through all the radiators 10 from the inlet valve 12a to the outlet valve 12b. The heat output is increased by an electric fan 30 which assists the air flow through the radiators 10 (forced convection). The optional temperature sensor 20, if present, can be used to control the fan 30 cut in and out. The radiator stack could be fixed in position or mounted on a trolley. As before, the solar/battery power supply is not shown. Figure 5 shows an embodiment of the invention for use in an engine-powered vehicle such as an emergency vehicle or marine craft, or for example a vehicle which is intended to be operated in cold climates in which one or more working fluids of the engine may freeze or become inoperably thickened due to the lowered temperature. In this embodiment, as well as having forced convection by a fan 30, the vehicle alternator 32 is used to charge the battery pack 24 when the vehicle's engine is running. The embodiment shows the heating element 16 fitted in line with the fluid inlet of the vehicle radiator 10 which regulates the temperature of the engine block, with the pump 14 being used to circulate the working fluid around the system. While the radiator 10 is, during normal operation of the vehicle, used to extract heat from the engine block and pass it to the environment, by fitting the heating element 16, the radiator operation can be effectively reversed such as to permit the radiator 10 to transfer heat back to the engine block. The working fluid within the radiator 10 and related network of piping can therefore be heated before the engine has been started, in order to heat the engine block, and the oil contained therein, to allow the engine to be started despite the significantly reduced temperature of the surrounding environment. The advantages of one or more embodiments of the invention are:

• No hydrocarbon fuel use

• No emissions

• Substantially reduced heat loss

· Rapid response to reaching required temperatures

• The higher the temperature of the PTC element the less power consumption so maintaining the temperature demands less power consumption.

• Can be powered directly by solar panels or a combination of solar panels and batteries.

• System will operate even if there is mains power cut unlike conventional heating systems in domestic, commercial or industrial buildings

• Unlike some of the modern day solar panels systems where heat pumps or an auxiliary heating system is necessary when snow or frost is on the roof and the solar panels coolant can have a potential of freezing, this is not a problem with the present invention.

• There is no pipe connections or routing of such pipe-work to roof solar panels reducing heat loss and coolant to be heated

• There is no flow and return pipes to be ran to boilers etc. Seriously reduced pipework and seriously reduced heat loss. Seriously reduced coolant to heat

• System will work even when no sunlight is available (at night) with battery reserve power.

• Can also be used of course to heat water for domestic purposes (domestic hot water). It will therefore be appreciated that the heating system of the present invention provides a relative simple yet effective means of regulating the temperature of a working fluid within a radiator system or the like.

Claims

1. A heating system comprising a liquid-filled radiator whose contained liquid is heated by an electrically powered positive temperature coefficient (PTC) heating element.

2. A heating system as claimed in claim 1 , wherein the electric power is at least partially derived from at least one of a battery, a mains supply and/or solar energy.

3. A heating system as claimed in claim 1 or 2, wherein the heated liquid is circulated in the radiator by a pump.

4. A heating system as claimed in claim 1 or 2, wherein the heated liquid is circulated in the radiator by convection.

5. A heating system as claimed in any preceding claim, wherein the radiator is selectively connectable to a separate source of heated fluid.

6. A heating system as claimed in any preceding claim, including an electric fan providing forced convection of the radiator.

7. A heating system as claimed in any preceding claim, wherein there are a plurality of stacked liquid-filled radiators through which the heated fluid circulates.

8. A heating system as claimed in any preceding claim mounted in an engine-powered vehicle, wherein the electric power is at least partially derived from a battery which is recharged by a vehicle alternator when the vehicle's engine is running.

9. A vehicle comprising a heating system according to any of the preceding claims, in which the temperature of one or more working fluids of the vehicle can be regulated by the heating system.

10. A vehicle according to claim 9 in which the heating element is mounted in line with a radiator of the vehicle, in order to permit the working fluid within the radiator to be heated prior to the engine being started.