WO1996017664A1

WO1996017664A1 - Combined heating and cooling apparatus and method therefor

Info

Publication number: WO1996017664A1
Application number: PCT/NZ1995/000129
Authority: WO
Inventors: Allick Royhit Lal
Original assignee: Allick Royhit Lal
Priority date: 1994-12-08
Filing date: 1995-12-08
Publication date: 1996-06-13
Also published as: AU4125396A

Abstract

This invention provides a combined heating and cooling apparatus utilising the heat pump to transfer exhaust heat from a cooling circuit and utilise this heat in the heating circuit. Control means may be provided such that when either the cooling circuit or heating circuit have achieved a suitable temperature, alternative heat exchangers can be brought into the circuit in alternative to the primary cooling or heating means. The distillation apparatus using such a combined heating and cooling apparatus is also provided.

Description

COMBINED HEATING AND COOLING APPARATUS AND METHOD THEREFOR

BACKGROUND TO THE INVENTION

This invention relates to improvements in and relating to combined heating and cooling apparatus and method therefor which allows for the recycling of heat between both heating and cooling systems for operation of, for example, a distillation process thereby providing reduced consumption of coolant than might otherwise occur where coolant was voided to waste and reduced energy consumption.

To the present time, various types of heating and cooling systems have been used for the operation of distillation apparatus. In general practice a heat source is applied to the vessel containing the liquid to be evaporated and a cooling source is applied to the condenser system to allow condensation of the evaporated liquid. In general laboratory operation the heating source is provided by an electric heating system, commonly an oil or water bath, and the cooling system is provided by a flow of tap water through the coils of the condenser. Where distillation is carried out under vacuum a water pump is commonly used to create the vacuum and in such cases the water is generally voided to waste. It is not uncommon for water consumption for a condenser to be of up to 600 litres per hour and for an aspirator or auto-vacuum pump to be of up to 3000 litres per hour with the obtainable maximum vacuum being limited by the ambient water temperature.

Under conditions in which water conservation is required distillation apparatus which demand a high consumption of water for a prolonged period are clearly unsatisfactory for prolonged use.

In other combined heating and cooling apparatus, energy consumption is dictated by the requirements for both the heating and cooling cycles acting individually. It would be preferable to provide an apparatus that allows for the exhaust heat from the cooling cycle to be used in the heating cycle as required.

OBJECT OF THE INVENTION

It is thus an object of the present invention to provide a combined heating and cooling apparatus such that where energy in the form of heat is required and where cooling is required, heat can be at least partially recycled from the cool cycle to the heating cycle, thereby overcoming some of the disadvantages of the prior art and/or to provide the public with a useful choice.

SUMMARY OF THE INVENTION

Accordingly, in a first aspect, the invention may broadly be said to consist in a combined heating and cooling apparatus comprising:

at least one first fluid container for the containment of fluid to be cooled;

at least one second fluid container for the containment of fluid to be heated;

a cooling means to cool the fluid within said first fluid container;

heating means to heat the fluid in said second fluid container;

a heat pump in communication with said cooling means and said heating means to pass heat from said cooling means to said heating means; and temperature control means to control the temperature in both cooled and heated fluid containers.

Accordingly, in a second aspect, the invention may broadly be said to consist in a distillation apparatus comprising:

(i) an evaporation chamber for the containment of fluid to be evaporated; (ii) a condensation chamber in communication with said evaporation chamber for the collection of evaporated fluid and the condensation of that fluid; (iii) a heated fluid container for the containment of heated fluid and in thermal communication with said evaporation chamber such that heat from said heated fluid in said heated fluid chamber may be used to evaporate the fluid in said evaporation chamber; (iv) a coolant chamber for the containment of coolant in thermal communication with said condensation chamber such that said contents of said condensation chamber may be cooled to cause the condensation of evaporated fluids within said chamber; and (v) a heat pump in communication with said heated fluid chamber and said coolant chamber so that the heat from post condensation coolant returned to said coolant chamber may be pumped to at least partially compensate for the heat provided to the evaporation chamber by said heated chamber.

Accordingly, in a third aspect, the invention may broadly be said to consist in a method of distilling fluid comprising the steps of:

(i) providing a fluid to be evaporated in an evaporation chamber; (ii) providing a condensation chamber in communication with said evaporation chamber; (iii) heating said evaporation chamber through the provision of heat from a heated fluid source;

(iv) cooling said condensation chamber through the provision of coolant from a coolant source; and

(v) providing a heat pump to transfer heat from post condensation coolant to said source of heated fluid to at least partially compensate for the heat lost from said source of heated fluid to said evaporation chamber. Accordingly, in a fifth aspect, the invention may broadly be said to consist in a distillation apparatus comprising:

an evaporation chamber for the containment of fluid to be evaporated;

a condensation chamber in communication with said evaporation chamber for the collection of evaporated fluid and the condensation of that fluid; and

a heat pump in communication with said evaporation and condensation chambers to pass heat from the condensation chamber to the evaporation chamber to simultaneously cool the evaporated fluid in the condensation chamber and heat the fluid to be evaporated in the evaporation chamber.

BRIEF DESCRIPTION OF THE DRAWINGS

Further aspects of this invention, which should be considered in all its novel aspects, will become apparent from the following description given by way of example of a possible embodiment thereof only and in which reference is made to the accompanying drawings as follows: Figure 1: Shows a schematic representation of one embodiment of the invention; Figure 2: Shows diagrammatically shows a view of one embodiment of the invention; Figure 3A, 3B and 3C:

Shows diagrammatically a flow through one embodiment of the invention; and Figure 4: Shows diagrammatically an electrical circuit for one embodiment of the invention; and Figure 5: shows diagrammatically a further embodiment of the invention; Figure 6: shows diagrammatically a further embodiment of the invention; and Figure 7: shows a yet further embodiment of the invention

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

It will be appreciated that the present invention is described in one embodiment particularly for use with distillation apparatus. However, it will be appreciated that the present invention has applications wherever there is a requirement to provide an efficient heat cycle system. This embodiment of the invention involves a heat and water recycling distillation apparatus which may include a double bath.

In the preferred embodiment of the invention represented diagrammatically in Figure 1, in which the flow of heat energy around the heat cycle is represented by arrows, the cold bath or coolant chamber (1) is shown interconnected to the hot bath or heated fluid container or chamber (2) by means of a heat pump (3) . The hot bath (2) provides heat to the evaporating means (4) said evaporating means (4) being partially immersed in the liquid in the hot bath (2) . Alternative arrangements are possible provided the transfer of heat from the heated fluid to the evaporation chamber (4) and contents occurs.

The evaporating means or chamber (4) contains the liquid (5) to be evaporated. The vapour produced from the liquid (5) is condensed on the condenser coils (6) within a condensation chamber (12) , said condenser coils (6) being supplied by way of a pump (not shown) with coolant from the cold bath (1) .

In the schematic representation shown in Figure 1 the evaporating means (4) and condensing coils (6) form part of the distillation apparatus (8) said distillation apparatus (8) in this embodiment being a rotary evaporator wherein the evaporating means (5) may be rotated by means of a motor (9) . In this embodiment the distillation apparatus may be connected to a vacuum pump by way of the two-way tap (10) and therefore the distillation process could be carried out at below atmospheric pressure. In the embodiment shown in Figure 1 vapour condensed on the condensing coil (6) forms a liquid which collects in a collection flask (not shown) .

It will be seen that in the Figure 1 embodiment heat transfer occurs from the hot bath (2) to the evaporating liquid (5) said evaporating liquid being vaporised and said vapour being condensed on the condensing coils (6) . By this means there is heat transfer from the vapour to the coolant liquid circulating in the condensing coils (6) . The transfer of heat to the coolant in the condensing coils causes a rise in temperature in the circulating coolant which is then transferred back to the cold bath (1) by means of the pump. Thus an increase in the temperature of the cold bath results. Heat from the cold bath (1) is then transferred by way of the heat pump (3) to the hot bath (2) to at least partially conserve the energy supplied by the hot bath (2) to the fluid (5) to be evaporated. A schematic view of the embodiment shown in Figure 1 is represented in Figure 2. In Figure 2 the cold bath

(1) and the heating bath (2) are not shown for clarity. A cooling means (14) and heating means (15) are connected to the compressor (16) being a closed loop heat pump, said compressor (16) being connected to a temperature control unit (not shown) . An air condenser (18) and air evaporator 19 are also provided. The operation of the compressor (16) is provided by an external power supply and control switch. In use the temperature of the baths is regulated through a thermostat/temperature display unit which allows for control of the temperature both of the cold bath (1) and the hot bath (2) . A temperature probe allows monitoring of the temperature in the cold bath (1) and a temperature probe allows monitoring of the temperature in the hot bath (2) .

In the event that the temperature of the hot bath

(2) is at the required temperature whereas the temperature of the cold bath (1) is above the required temperature for that bath, the temperature control unit allows the air condenser (18) to dispel the excess heat rather than overheating the hot bath (2) .

Similarly the air evaporator may be used to supply heat to the system if the cold bath (1) is sufficiently cooled and further heating of the hot bath (2) is required.

Referring to figure (2) , an expansion valve (20) is shown to provide a low pressure fluid of reduced temperature prior to the fluid returning to the cooling means being a water evaporator or similar (14) .

The heating means (15) may comprise a water condenser or similar heat exchange apparatus.

Figure 2 also shows a number of solenoid valves (21), (22), (23), (24), (25) and (26) . These solenoid valves may be controlled by a suitable control means to divert the flow as necessary through the circuit to bring the air condenser (18) or air evaporator (19) into operation.

It should also be noted that in a distillation apparatus of this type, a magnetic stirrer may be provided in the hot bath (2) so that heat transfer is facilitated.

Turning now to figures (3a) , (3b) and (3c) , the operation of the general circuit is shown. The arrows on each of these diagrams indicate the flow of fluid through the heat transfer apparatus. If required, non return valves (27) and (28) may be provided in the fluid circuit providing the heat transfer.

Referring to figure (3a) , the operation of the apparatus can be observed while both heating and cooling are simultaneously taking place. Fluid through the heat transfer apparatus flows from the compressor (16) which supplies a high pressure high temperature fluid through open solenoid valve (21) to a heat exchanger (15) to provide such heat as may be required to the hot bath of the distillation apparatus or, in other embodiments, a hot water tank or similar. The high pressure fluid which is now of a reduced temperature having passed through the heat exchanger (15) may then run through the non return valve (27) and along conduit loop (29) until it passes through the thermostatic expansion valve (20) .

Having passed through this expansion valve, the high pressure fluid is reduced to a low pressure fluid of cold temperature. This may then travel through solenoid valve 25 and through the heat exchanger (14) to provide such cooling as may be required. The fluid then returns to the compressor (16) and is recycled.

Referring to figure (3b) , the same apparatus can be seen in which solenoid valve (21) has been closed and solenoid valve (22) opened so that the fluid flow through the heat transfer apparatus is diverted through an alternative heat exchanger such as an air condenser (18) rather then through the heating means (15) . This may be the circuit in operation when sufficient heat has been supplied by the heating means (15) for its purpose and yet additional cooling is still required.

Referring to figure (3c) , if sufficient cooling has been provided by the cooling means (14) and yet heating is still required by the heat means (15) , solenoid valve (25) may close and solenoid valve (26) open so that the cooling side of the apparatus is now directed through an alternative heating exchanger (19) so that the cooled fluid entering the heat exchanger (19) may be heated before returning to the compressor (16) .

Figure (4) shows a possible circuit diagram for controlling the distillation apparatus shown in the previous figures.

It can be seen that the electrical diagram provides controllers (30) and (31) over the heating and cooling circuits respectively with probes (32) and (33) provided to check the temperature in the hot and cold baths as required. From an AC power supply, power may be supplied to the heat pump circuit as well as to a cold water circulation pump to drive the cold water through the condensating coil, power to the Venturi pump if the condensation of the distillate is done under vacuum and power to the hot water magnetic stirrer.

On the heat pump circuit, power can be supplied via relays to the necessary solenoid valves with the solenoid valves SI, S2, S3, etc relating to solenoid valves (21) , (22) , (23) , etc previously described.

Referring now to figure 5, an alternative configuration could be seen in which the heat exchange unit is provided in line with the previous embodiments. However, in this embodiment, pump units (34) and (35) are provided to transfer fluid from a cooling slave tank (36) and boiling slave tank (37) respectively. Such an embodiment may be of use when dealing with volatile materials so that the entire heat transfer side of the apparatus including all control gear and switching may be isolated from the area in which distillation takes place. The pump units (34) and (35) merely transfer fluid from the slave tanks to the respective heat exchangers (14) and (15) . Referring now to figure (6) , a similar distillation apparatus can be seen although in this embodiment no cold and hot water baths are provided. Instead, heat exchangers (14) and (15) operate directly on the solvent and distillate. As can be seen, a filling pump (38) with a suitable float switch (40) may be used to keep a continuous level of solvent in an evaporation chamber (4) which houses the heating heat exchanger (15) . Material evaporated from the solvent may then pass along passage (39) to a condensating chamber (12) being directly in contact with the evaporative heat exchanger (14) . Distillate may be taken from the chamber (12) as it is produced. Unlike the previous embodiments, no buffer of cold and hot baths is provided, however, the operation of the heat transfer is the same.

Referring now to figure (7) , the same heat transfer apparatus can be seen to operate a hot water heating tank and an air conditioning unit. Again, the cooling means (14) and heating means (15) operate directly in conjunction with the air conditioning and hot water heating tank respectively. Control of the apparatus may again be provided to bring into use an air condenser (18) or air evaporator (19) as required.

Thus it can be seen that the apparatus provides a general combined heating and cooling apparatus as well as specific applications relating to distillation which utilise some of the energy redundant from the cooling cycle into the heating cycle of the apparatus.

Claims

1. A combined heating and cooling apparatus comprising:

at least one first fluid container for the containment of fluid to be cooled;

at least one second fluid container for the containment of fluid to be heated;

a cooling means to cool the fluid within said first fluid container;

heating means to heat the fluid in said second fluid container;

a heat pump in communication with said cooling means and said heating means to pass heat from said cooling means to said heating means; and

temperature control means to control the temperature in both cooled and heated fluids.

2. A combined heating and cooling apparatus as claimed in claim 1 wherein said cooling means comprises a heat exchanger utilising a coolant to reduce the temperature of the fluid to be cooled and said heating means comprises a heat exchanger using a heated fluid to pass heat to the fluid to be heated.

3. A combined heating and cooling apparatus as claimed in claim 2 wherein said heat pump may draw heat from the coolant after having taken heat from said fluid to be cooled and supply said heat to the fluid to be used in the heat exchanger to heat the fluid to be heated.

4. A combined heating and cooling apparatus as claimed in claim 3 wherein an alternative heat exchanger is provided to supply heat to said heat pump which passes heat to the fluid to be heated when said cooled fluid has reached the desired temperature.

5. A combined heating and cooling apparatus as claimed in claims 3 wherein an alternative heat exchanger is provided to remove heat from said heat pump which extracts heat from the fluid to be cooled when said heated fluid has reached the desired temperature.

6. A combined heating and cooling apparatus as claimed in claims 4 and 5 wherein two alternative heat exchangers are provided.

7. A combined heating and cooling apparatus as claimed in claim 6 wherein said temperature control means controls the operation of said heat pump and can introduce either of said two alternative heat exchangers as required.

8. A distillation apparatus comprising:

(a) an evaporation chamber for the containment of fluid to be evaporated;

(b) a condensation chamber in communication with said evaporation chamber for the collection of evaporated fluid and the condensation of that fluid;

(c) a heated fluid container for the containment of heated fluid and in thermal communication with said evaporation chamber such that heat from said heated fluid in said heated fluid chamber may be used to evaporate the fluid in said evaporation chamber;

(d) a coolant chamber for the containment of coolant in thermal communication with said condensation chamber such that said contents of said condensation chamber may be cooled to cause the condensation of evaporated fluids within said chamber; and (e) a heat pump in communication with said heated fluid chamber and said coolant chamber so that the heat from post condensation coolant returned to said coolant chamber may be pumped to at least partially compensate for the heat provided to the evaporation chamber by said heated chamber.

9. A distillation apparatus as claimed in claim 8 wherein said heated fluid chamber comprises a bath of heated fluid in which said evaporation chamber may be partially immersed.

10. A distillation apparatus as claimed in claim 8 or claim 9 wherein said coolant is communicated to said condensation chamber through a coil carrying said coolant through said condensation chamber.

11. A distillation apparatus as claimed in any one of claims 8 to 10 wherein said apparatus includes a vessel in communication with said condensation chamber to collect said condensation fluid.

12. A distillation apparatus as claimed in claim 10 wherein a fluid pump is provided to pump said coolant from said coolant chamber through said condensation coil.

13. A distillation apparatus as claimed in any one of claims 8 to 12 wherein said coolant chamber and heated fluid chamber are provided in a double bath separated by said heat pump.

14. A distillation apparatus as claimed in any one of claims 8 to 13 wherein said condensation chamber is provided with a connection means for the connection of vacuum to said chamber.

15. A method of distilling fluid comprising the steps of:

(a) providing a fluid to be evaporated in an evaporation chamber;

(b) providing a condensation chamber in communication with said evaporation chamber;

(c) heating said evaporation chamber through the provision of heat from a heated fluid source;

(d) cooling said condensation chamber through the provision of coolant from a coolant source; and (e) providing a heat pump to transfer heat from post condensation coolant to said source of heated fluid to at least partially compensate for the heat lost from said source of heated fluid to said evaporation chamber.

16. A distillation apparatus comprising: an evaporation chamber for the containment of fluid to be evaporated;

17. The distillation apparatus as claimed in claim 16 wherein an evaporative heat exchanger is provided in the condensation chamber and a heating heat exchanger is provided in the evaporation chamber and a fluid circuit to carry a heat exchanging fluid is provided interconnecting said heat exchangers with a compressor in said fluid circuit to compress fluid flowing from the evaporative of heat exchanger to the heating heat exchanger and an expansion valve in the circuit from the heating heat exchanger to the evaporative heat exchanger.

18. A distillation apparatus as claimed in claim 17 wherein a secondary evaporator is provided in parallel in the fluid circuit to the evaporative heat exchanger.

19. A distillation apparatus as claimed in claim 17 wherein a secondary condenser is provided in parallel with said heating heat exchanger in said fluid circuit.

20. A distillation apparatus as claimed in 18 and claim 19 wherein said secondary evaporator and said secondary condenser are both provided respectively in parallel with said evaporative heat exchanger and said heating heat exchanger.

21. A combined heating and cooling apparatus substantially is hereinbefore described with reference to the accompanying drawings.

22. A distillation apparatus substantially as hereinbefore described with reference to the accompanying drawings.

23. A method of distilling fluid substantially as hereinbefore described with reference to the accompanying drawings.