GB2525963A

GB2525963A - Apparatus for providing three separate functions of heating, cooling, and simultaneous heating and cooling

Info

Publication number: GB2525963A
Application number: GB1503695.7A
Authority: GB
Inventors: Andrew John Ingram
Original assignee: I I ICE Ltd
Current assignee: I I ICE Ltd
Priority date: 2014-04-30
Filing date: 2015-03-03
Publication date: 2015-11-11
Anticipated expiration: 2035-03-03
Also published as: GB201407668D0; GB2525963B; GB201503695D0

Abstract

Apparatus 2 for providing three separate functions of heating (winter mode), cooling (summer mode), and simultaneous heating and cooling (autumn and spring mode). The apparatus comprises a heat pump section 4 for providing the heating, a chiller section 6 for providing the cooling, and a balancing section 8 for providing heating or cooling. The apparatus being such that the chiller is connected to the heat pump whereby the chiller is able to expel heat to the heat pump to provide cooling; the heat pump is connected to the chiller whereby the heat pump is able to obtain heat from the chiller to provide heating; the chiller is connected to the balancing section whereby when heat is not required to be expelled by the chiller to the heat pump then heat is able to be expelled by the chiller to the balancing section with the balancing section then acting as a heat sink; the heat pump is connected to the balancing section whereby when the heat pump requires heat to provide the heating and the heat is not available from the chiller, the heat pump is able to draw heat from the balancing section then acting as a heat source.

Description

I

APPARATUS FOR PROVIDING THREE SEPARATE FUNCTIONS OF

HEATING. COOLING, AND

SIMULTANEOUS HEATING AND COOLING

This invention relates to apparatus for providing heating and cooling.

More especially, this invention relates to apparatus which is for providing heating and cooling, and which operates with heat recovery.

Apparatus is known which is for heating and cooling and which operates with heat recovery. The known apparatus is not as efficient as desired in its heat recovery. There may be conditions in summer, autumn, winter and spring when environmental conditions prevent the required heat recovery.

It is an aim of the present invention to obviate or reduce the above mentioned problem.

Accordingly, in one non-limiting embodiment of the present invention there is provided apparatus for providing three separate functions of heating, cooling, and simultaneous heating and cooling, the separate functions being provided to means requiring the functions, and the apparatus comprising: (i) a heat pump section for providing heating; (ii) a chiller section for providing cooling; and (iii) a balancing section for use in providing heating and/or cooling, and the apparatus being such that: (iv) the chiller section is so connected to the pump section that the chiller section is able to expel heat to the heat pump section and thereby provide cooling; (v) the heat pump section is so connected to the chiller section that the heat pump section is able to obtain heat from the chiller section and thereby provide heating; (vi) the chiller section is so connected to the balancing section that when heat is not required to be expelled by the chiller section to the heat pump section then heat is able to be expelled by the chiller section to the balancing section with the balancing section then acting as a heat sink; (vii) the heat pump section is so connected to the balancing section that when the heat pump section requires heat in order to provide heating and the heat is not available from the chiller section, then the heat pump section is able to draw heat from the balancing section with the balancing section then acting as a heat source; and (viii) the apparatus includes flow and return conduits which connect the chiller section to the heat pump section, and the heat pump section to the balancing section, and which enable the apparatus to provide the three separate functions of the heating, the cooling, and the simultaneous heating and cooling.

The apparatus of the present invention is advantageous in that the balancing section enables the apparatus to operate with required heat recovery irrespective of whether the apparatus is operating in summer, autumn, winter or spring. The balancing section is able to act as a heat sink when required, and also a heat source when required. The balancing section also enables the apparatus to provide the three separate functions of the heating, the cooling. and the simultaneous heating and cooling. The provision of the simultaneous heating and cooling is advantageous in conditions such for example as those encountered in autumn or spring when some parts of the means requiring the three separate functions of heating, cooling and simultaneous heating and cooling may require the heating and some other parts may require the cooling.

The means requiring the three separate functions of the heating, the cooling, and the simultaneous heating and cooling may be a building or a process. The building may typically be industrial premises such for example as factories, offices or supermarkets. The building may alternatively be domestic premises such for example as blocks of flats. The process may be any one of a wide variety of chemical processes.

The apparatus of the present invention may include defrost means for defrosting the balancing section in winter when the balancing section is acting as a dry air cooler and is relying on ambient conditions which are cold enough to cause frosting of the balancing section.

The defrost means may comprise at least one extra heat exchanger where heat recovery can take place, and conduit means for enabling the heat recovered from the extra heat exchanger to be pumped over the balancing section. Other types of defrost means may be employed.

The apparatus of the present invention may include a three-way control valve for use in providing desired control of the apparatus for balancing the operation of the heat pump section and the chiller section. The three-way valve may be so connected as to balance the apparatus by controlling the amount of flow into the chiller section, or diverting the flow back around the apparatus so that more heat can be recovered. Other types of control means for balancing the operation of the heat pump section and the chiller section may be employed.

The apparatus may include a buffer section for storing heat or cold that is not required and that would otherwise be expelled to ambient. The buffer section may include one or more buffer tanks.

The apparatus may be one in which the heat pump section comprises an evaporator, a compressor, and a condenser, in which the evaporator is a plate1ype heat exchanger or a shell and tube-type heat exchanger, and in which the condenser is a plate-type heat exchanger or a shell and tube-type heat exchanger. Other constructions for the heat pump section may be employed.

The apparatus may be one in which the chiller section comprises an evaporator, a compressor, and a condenser, in which the evaporator is a plate-type heat exchanger or a shell and tube-type heat exchanger, and in which the condenser is a plate-type heat exchanger or a shell and tube-type heat exchanger. Other constructions for the chiller section may be employed.

The apparatus may be one in which the heat pump section comprises a pump which connects between an outlet from the balancing section and an inlet to the condenser of the chiller section.

Embodiments of the invention will now be described solely by way of example and with reference to the accompanying drawings in which: Figure 1 shows first apparatus of the present invention; Figure 2 shows second apparatus of the present invention which is like the first apparatus of the present invention but which is additionally provided with a defrost facility for a chiller section forming part of the apparatus: and Figure 3 shows third apparatus of the present invention and which is like the apparatus shown in Figure 2, but which additionally includes a three-way control valve for use in providing desired control of the apparatus for balancing the operation of a heat pump section and a chiller section of the apparatus.

Referring to Figure 1, there is shown apparatus 2 for providing three separate functions of heating, cooling, and simultaneous heating and cooling.

The separate functions of the heating, cooling, and simultaneous heating and cooling are provided to means requiring the functions. Typically the means requiring the functions is a building or a process.

The apparatus 2 comprises a heat pump section 4 for providing heating, a chiller section 6 for providing cooling, and a balancing section 8 for use in providing heating and/or cooling.

The apparatus 2 is such that the chiller section 6 is so connected to the heat pump section 4 that the chiller section 6 is able to expel heat to the heat pump section 4 and thereby provide cooling.

The heat pump section 4 is so connected to the chiller section 6 that the heat pump section 4 is able to obtain heat from the chiller section 6 and thereby provide heating.

The chiller section 6 is so connected to the balancing section 8 that when heat is not required to be expe'led by the chiller section 6 to the heat pump section 4, then heat is able to be expelled by the chiller section 6 to the balancing section 8 with the balancing section 8 then acting as a heat sink.

The heat pump section 4 is so connected to the balancing section 8 that when the heat pump section 4 requires heat in order to provide heating and the heat is not available from the chiller section 6, then the heat pump section 4 is able to draw heat from the balancing section 8 with the balancing section 8 then acting as a heat source.

The apparatus 2 includes flow and return conduits 10, 12 for providing cooling or air conditioning to the means requiring the functions, for example the building or the process. The apparatus 2 further includes flow and return conduits 14, 16 for providing heating to the means requiring the functions, for example the building or the process. The apparatus 2 has connecting conduits whereby the apparatus 2 is able to provide the three separate functions of the heating, the cooling, and the simultaneous heating and cooling.

The heat pump section 4 comprises an evaporator 18, a compressor 20, and a condenser 22. The evaporator 18 may be a plate-type heat exchanger, or it may be a shell and tube-type heat exchanger. The condenser 22 may be a plate-type heat exchanger, or it may be a shell and tube-type heat exchanger. The heat pump section 4 also includes a pump 24 and a valve 26. The valve 26 is a flow control valve 26 and it may be an expansion valve or a float valve. The evaporator 18, compressor 20, condenser 22, pump 24 and valve 26 in the heat pump section 4 are connected as shown, with fluid flow being indicated by the arrows.

The chiller section 6 comprises an evaporator 28, a compressor 30, and a condenser 32. The evaporator 28 may be a plate-type heat exchanger, or it may be a shell and tube-type heat exchanger. The condenser 32 may be a plate-type heat exchanger, or it may be a shell and tube-type heat exchanger. The chiller section 6 further includes a valve 34. The valve 34 is a flow control valve. The valve 34 may be an expansion valve or a float valve.

The evaporator 28, compressor 30, condenser 32 and valve 34 in the chiller section 6 are connected as shown, with fluid flow being indicated by the arrows.

The apparatus 2 may operate with any appropriate operational fluid.

The operational fluid may be any medium which is naturally stable as a liquid at normal ambient conditions, or it may be a medium in a pressurised system where the liquid, at a pressurised pressure operates stabily in the liquid form so that it absorbs and expels heat energy without changing state. The fluid may be a liquid or a gas. Examples of liquids are water, glycol or tyfoxit.

Examples of gases are carbon dioxide or nitrogen.

If the chiller section 6 is operating, then its condenser 32 is working to expend heat from the refrigeration process that is cooling from conduits 10, 12 connected to the building or process. Thus if the chiller section 6 is working, then heat energy will be expelled out of the condenser 32 and into circulating operational fluid, for example glycol that will warm up. This may be effected at point 33 shown in Figure 1. The circulating fluid then travels to the evaporator 18 of the heat pump section 4 via point 35 in the conduit system for the apparatus 2. Heat energy in the operating fluid, for example a glycol/water mix, is absorbed by the evaporation process at the evaporator 18 if the heat pump section 4 is working. This heat energy is then expelled at conduits 16, 14 so that the heat section 4 is able to provide heat to the building or process.

If the heat section 4 is not operating, then heat energy will not be absorbed by the heat section 4. In this case, the heat energy leaves the evaporator 18 in the heat pump section 4 at point 37, with this heat being in the glycol passing through the evaporator 18. The glycol will be warm glycol and it will travel to the balancing section 8 which acts as an external heat exchanger because it will be warmer than the ambient. The heat will then be expelled from the heat exchanger section 8 so that the heat exchanger section 8 then acts as a heat sink in order to cool the glycol. The expelling of the heat may occur naturally, or it may be forced via a fan of a dry air cooler forcing air across the balancing section 8.

When the glycol leaves the balancing section 8, itis cooled. The glycol enters the balancing section 8 at position 39 and leaves at position 41.

Thereafter, the glycol travels to the pump 24, having been cooled already by the heat sink function of the balancing section 8. The glycol then travels back around the system to start the process all over again, entering the condenser 32 of the chiller section 6 at point 43.

If the chiller section is not running, there will be no cooling required.

Since there is a continuous circuit, the glycol leaves in an unheated condition because the chiller section is not running. In this case, the glycol leaves at position 33 and goes to position 35 for the evaporator 18 of the heat pump section 4. In the evaporator 18, heat is removed from the glycol so that the glycol is cooled. The cooled glycol leaves the evaporator 18 of the heat pump section 4 at point 37 and then travels to position 39 where it enters the balancing section 8 which acts as an outside heat exchanger. Because the temperature is getting colder than the ambient, heat energy is absorbed in the glycol so that the balancing section 8 then becomes a heat source. The warmed glycol leaves the balancing section 8 at point 41 and then passes to the heat pump 24. The heat pump 24 pumps the glycol back around the circuit to the point 43. The operational fluid enters the condenser 32, and the chiller section 6 commences operation so that the circuit starts all over again.

The balancing section 8 is able to act as a heat sink or a heat source.

The balancing section 8 may be either a geothermic heat exchanger under the ground, or an ambient dry air cooler, Either acts the same as a heat exchanger. If the system is in a balanced condition, i.e. the chiller section 6 is running and providing cooling for the building or process from pipes at connections 12, 10, and the heat pump section 4 is running in balance producing heat at the connections 14, 16, then the entire system is balanced.

If for example there is an ambient of 16° air or geothermic ground temperature of 16°C, then the apparatus 2 is balanced with both units running off the heat pump section 4 and the chiller section 6.

Considering the chiller section 6, if the chiller section 6 is switched off because it has achieved temperature and load, and heating is still required, then the apparatus 2 is able to draw heat from the glycol section between the balancing section 8 and the condenser 32 in the chiller section 6 and the evaporator 18 in the heat pump section 4. As heat energy is absorbed, then the glycol circulating in the circuit to the balancing section 8 starts to drop in temperature. Once the glycol drops below 16°C, the heat energy starts naturally being absorbed into the heat exchanger. If the apparatus 2 acts as a dry air cooler, then a sensor may switch on fans in order to obtain forced convection. As the temperature drops still further, more energy is absorbed into a glycol heat exchanger in the balancing section 8, and this supplies the balance to the system. If then the chiller section 6 starts back up, then the glycol starts to warm up and balance is then achieved again. If then the chiller section 6 is still running, and the heat pump section 4 is achieving its required temperature and loads and switches off, then again the apparatus 2 operates to expel heat from the chiller section into the glycol and the glycol starts to warm up. As the glycol warms past 16°c, then the glycol starts to expel heat energy in the heat exchanger in the balancing section 8. The heat energy is expelled to ambient or geothermal. The expelled heat enables the system to rebalance as the glycol is circulated around. Again, if the heat pump then starts back up and starts absorbing the heat energy, then balance of the apparatus 2 is again achieved.

The balancing section 8 can also work at other temperatures than that mentioned above. Control systems may be employed to cause fans to operate at different temperatures. Geothermic temperature is basically substantially stable at 16°C but an ambient dry air cooler has more variant temperature, and may be controlled via a three-way control valve or a combination of the three-way control valve and fans.

The apparatus 2 may operate as follows. Any heat from a process or air conditioning units in a building can be recycled to enter the evaporator 28 of the chiller section 6. All of the heat energy is then pumped over the condenser 32 of the chiller section 6. Here the operational liquid, for example the glycol or water, removes the heat energy from the condenser 32. The heat energy then enters the evaporator 18 of the heat pump section 4.

Substantially all of the heat energy is recovered. Any excess heat energy that is not absorbed or required by the apparatus 2 can be exhausted to the balancing section 8 acting as a dry air cooler, or to the balancing section 8 acting as a geothermal heat exchanger and expelled to the ambient.

The heat energy is able to be pumped over to the condenser 22 of the heat pump section 4, where another operational fluid system for an air conditioning water system is able to remove the heat energy so that the apparatus 2 can provide heat for the building or process via the flow and return conduits 14, 16. By connecting the heat pump section 4 to the chiller section 6 as shown, instead of a low grade heat source being recoverable and usable, a much higher heat source medium is recoverable and usable.

For example, instead of a 30°C water temperature, a 600 -70°C water outlet temperature may be achieved. For heat energy efficiency, a 40 -50 medium of hot water -glycol may be employed. The heat energy expelled can in turn go to the building or process requiring the heating.

The balancing section 8 is able to operate as a dry air cooler forming a heat source, or as a thermal heat exchanger when it acts as a heat sink. In winter, there may not be a great deal of heat energy coming out of the building or process. In this case, required heat energy can be taken from the balancing section 8 to balance the requirements of the apparatus 2, and thereby to enable the apparatus 2 to provide the heating loads required by the building or process.

In summer, heating may not be required. In this case, the chiller section 6 is able to expel heat energy to the balancing section 8 with the balancing section 8 then acting as a heat sink. The balancing section 8 may be regarded as a combined dry air cooler and geothermic heat exchanger.

In autumn or spring, the two functions of heating and cooling may simultaneously be required. More specifically, some parts of a building or process may require chilling or cooling, whilst other parts of the building or process may require heating. The process may be a simple process, or a combination of processes. The apparatus 2 is able to provide at the same time both the required cooling and the required heating. The balancing section 8 balances the total heat recovery from the ambient, or the total heat reject to the ambient. Thus the apparatus 2 is able to provide the three separate functions of the heating, the cooling, and the simultaneous balanced heating and cooling all year round and as required. This is all provided from one piece of apparatus 2. In contrast, with known apparatus 2 employing a heat pump, it is only possible to have the separate functions of heating or cooling, and it is not possible to have the additional function of the simultaneous balanced heating and cooling. Also, with known systems, and as mentioned above, the heat recovered is of a low temperature. With the apparatus 2, the building or process is able to have required heating and cooling all year around, and importantly in spring and autumn when the building or process may have a part or parts requiring heating, and simultaneously have another part or parts requiring cooling. The apparatus 2 is thus extremely versatile.

If desired, the apparatus 2 may be used with critically charged ammonia systems to provide a good coefficient of performance, and zero global warming and ozone depletion. This makes the apparatus 2 very advantageous. Also, because the heat pump section 4 and the chiller section 6 can be critically charged with ammonia, very small charges of ammonia can be used. Thus ammonia is able to be used in conditions where it would normally be excluded in known apparatus for having a toxic and/or explosive potential.

Referring now to Figure 2. there is shown apparatus 44 for providing three separate functions of heating, cooling, and simultaneous heating and cooling. The apparatus 44 is like the apparatus 2, and similar parts have been given the same reference numerals for ease of comparison and understanding.

The apparatus 44 differs from the apparatus 2 in that the apparatus 44 includes defrost means 46 for defrosting the balancing section 8 in winter when the balancing section 8 is acting as a dry air cooler and is relying on ambient conditions which are cold enough to cause frosting of the balancing section 8. The defrost means 46 comprises at least one extra heat exchanger 48 where heat recovery can take place. The defrost means 46 also includes conduit means as shown for enabling the heat recovered from the extra heat exchanger 46 to be pumped over the balancing secUon 8. More specifically, the heat exchanger 48 is connected via a pipe 50 to the condenser 22 of the heat pump section 4. The heat exchanger 48 is provided with an outlet pipe 52 for providing hot water to a building or process as required. The heat exchanger 48 is connected to a pump 54 as shown for pumping operational fluid to the balancing section 8. The balancing section 8 is shown as comprising two balancing units 56, 58, whereas the balancing section in the apparatus 2 shown in Figure 1 comprises only one balancing unit. The balancing unit 56 is provided with fans 60. The balancing unit 58 is provided with fans 62. Solenoid control valves 64, 66, 68, 70, 72, 74 are connected in circuit as shown.

The apparatus 44 is able to operate to provide a defrost facility for the balancing section 8 in winter. More specifically, when the balancing section 8 is acting as a dry air cooler with the illustrated balancing units 56, 58, then reliance will be placed on air temperature for providing a heat source/heat sink facility. A geothermal source is able to have a very constant temperature.

However, when acting as dry air coolers, the balancing units 56, 58 will be relying on ambient conditions which will not provide a constant temperature.

Thus the balancing units 56, 58 may be exposed to very low or high temperatures. High temperatures are not a problem. However low temperatures can cause the balancing units 56, 58 to start freezing up. If this occurs, then the balancing units 56, 58 may start to blind-side with ice. This means that their efficiency drops off dramatically, and insufficient or no heat energy can be absorbed from the ambient. The apparatus 44 overcomes the problem by providing the defrost facility which involves providing the balancing section 8 with the two balancing units 56, 58. If desired, a further one or more balancing units may be employed.

The apparatus 44 operates such that it uses the hot water outlet to go through the defrost heat exchanger 48 where heat recovery can take place.

The heat recovery from the heat exchanger 48 is then pumped over the balancing units 56, 58 acting as dry air coolers. The solenoid control valves 64, 66, 68, 70, 72, 74 are inlet and outlet solenoid control valves as can be appreciated. When the valves close, hot glycol (or other operational liquid) from the heat exchanger 48 is pumped throUgh the balancing unit 56, thereby defrosting the entire balancing section 88. This gives the advantage that the apparatus 44 is able to work at temperatures as low as -10°C ambient. The apparatus 44 is thus able to operate at low ambient conditions, in addition to being able to provide required heating and cooling to building or processes all the year round in the same manner as described above with reference to the apparatus 2.

Referring now to Figure 3, there is shown third apparatus 76 of the present invention. The apparatus 76 is like the apparatus 44. Similar parts have been given the same reference numerals for ease of comparison and understanding.

The apparatus 76 includes a 3-way control valve 78. The control valve 78 is for use in providing desired control of the apparatus 76 for balancing the operation of the heat pump section 4 and the chiller section 6. As can be seen from Figure 3, the control valve 78 is so connected as to balance the apparatus 76 by controlling the amount of flow into the chiller section 6, or diverting the flow back around the apparatus 76 so that more heat can be recovered.

The provision of the 3-way control valve 78 allows more versatile control and closer control of the apparatus 76, in order to balance the chiller section 6, and the heat recovery of the heat pump section 4. The control valve 78 enables close control of water temperatures leaving the evaporators. It also enables close control of the water temperatures leaving the condenser of the chiller section 6. The control valve 78 basically keeps the temperature constant. By keeping the temperature constant, the control valve 78 allows the apparatus 76 to be balanced more accurately than just losing/gaining excess heat through the balancing section 8 when low or high ambient temperatures are present. The control valve 78 allows close control of the heat pump section 4 and the chiller section 6 in order to maintain a constant output.

It is to be appreciated that the embodiments of the invention described above with reference to the accompanying drawings have been given by way of example only and that modifications may be effected. Thus, for example, the points 33, 35, 37, 39, 41 and 43 may be regarded as positions or connects. Where reference has been made to glycol, then the glycol may alternatively be another operational fluid. Where reference has been made to a building or process, then these may alternatively be another means requiring the functions. The apparatus 2, 44, 76 may include a buffer section for storing heat that is net required during a period of operation of the apparatus 2, 44, 76 and that would otherwise be expelled to ambient.

Individual components shown in the drawings are not limited to use in their drawings and they may be used in other drawings and in all aspects of the invention.

Claims

CLAIMSApparatus for providing three separate functions of heating, cooling, and simultaneous heating and cooling, the separate functions being provided to means requiring the functions, and the apparatus comprising: (i) a heat pump section for providing heating; (ii) a chiller section for providing cooling; and (iii) a balancing section for use in providing heating and/or cooling, and the apparatus being such that: (iv) the chiller section is so connected to the pump section that the chiller section is able to expel heat to the heat pump section and thereby provide cooling; (v) the heat pump section is so connected to the chiller section that the heat pump section is able to obtain heat from the chiller section and thereby provide heating; (vi) the chiller section is so connected to the balancing section that when heat is not required to be expelled by the chiller section to the heat pump section then heat is able to be expelled by the chiller section to the balancing section with the balancing section then acting as a heat sink; (vii) the heat pump section is so connected to the balancing section that when the heat pump section requires heat in order to provide heating and the heat is not available from the chiller section, then the heat pump section is able to draw heat from the balancing section with the balancing section then acting as a heat source; and (viii) the apparatus includes flow and return conduits which connect the chiller section to the heat pump section, and the heat pump section to the balancing section, and which enable the apparatus to provide the three separate functions of the heating, the cooling, and the simultaneous heating and cooling.
2. Apparatus according to claim 1 in which the means requiring the functions is a building or a process.
3. Apparatus according to claim I or claim 2 and including defrost means for defrosting the balancing section in winter when the balancing section is acting as dry air cooler and is relying on ambient conditions which are cold enough to cause frosting of the balancing section.
4. Apparatus according claim 3 in which the defrost means comprises at least one extra heat exchanger where heat recovery can take place, and conduit means for enabling the heat recovered from the extra heat exchanger to be pumped over the balancing section.
5. Apparatus according any one of the preceding claims and including a three-way control valve for use in providing desired control of the apparatus for balancing the operation of the heat pump section and the chiller section.
6. Apparatus according to claim 5 in which the three-way valve is so connected as to balance the apparatus by controlling the amount of flow into the chiller section, or diverting the flow back around the apparatus so that more heat can be recovered.
7. Apparatus according to any one of the preceding claims and including a buffer section for storing heat that is not required and that would otherwise be expelled to ambient.
8. Apparatus according to claim 7 in which the buffer section includes a buffer tank.
9. Apparatus according to any one of the preceding claims in which the heat pump section comprises an evaporator, a compressor, and a condenser, in which the evaporator is a plate-type heat exchanger or a shell and tube-type heat exchanger, and in which the condenser is a plate-type heat exchanger or a shell and tube-type heat exchanger.
10. Apparatus according to any one of the preceding claims in which the chiller section comprises an evaporator, a compressor, and a condenser, in which the evaporator is a plate-type heat exchanger or a shell and tube-type heat exchanger, and in which the condenser is a plate-type heat exchanger or a shell and tube-type heat exchanger.
11. Apparatus according to claim; 10 in which the heat pump section comprises a pump which connects between an outlet from the balancing section and an inlet to the condenser of the chiller section.
12. Apparatus for providing three separate functions of heating, cooling, and simultaneous heating and cooling, substantially as herein described with reference to the accompanying drawings.