ES2979381B2 - HIGH ENERGY EFFICIENT AIR CONDITIONING SYSTEM FOR BUILDINGS THAT INCLUDES INLET FOR THE AIR FLOW INTAKED FROM THE OUTSIDE AND OUTLET FOR THE TREATED SUPPLY AIR FLOW - Google Patents

Description

HIGH ENERGY EFFICIENT AIR CONDITIONING SYSTEM FOR BUILDINGS THAT INCLUDES INLET FOR THE AIR FLOW INTAKED FROM THE OUTSIDE AND OUTLET FOR THE TREATED SUPPLY AIR FLOW

OBJECT OF THE INVENTION

The present invention reveals an air conditioning system that incorporates a compact and autonomous unit that is capable of providing a very high quality of indoor air with a very high energy efficiency compared to current conventional air conditioning systems, affecting the reduction of the dry temperature of the outside air, total renewal of the indoor air, without recirculating or impoverishing it, providing an optimal indoor relative humidity for health and comfort, ionization of the indoor air.

BACKGROUND OF THE INVENTION

Human comfort and productivity require close control of temperature and humidity. Fossil fuels have been used for centuries to supply heat, and in recent years refrigeration equipment that effects the transfer of thermal energy by mechanical means involving the compression and expansion of a working fluid has been used for cooling and humidity control. Observation confirms that most such refrigeration equipment uses electric power as its primary source of energy, and indeed the rapid growth in air conditioning capacity in recent years has placed virtually intolerable demands on electric utility systems; and has similarly increased the demand for power plants and waste heat rejection and cooling facilities.

Air conditioning installations for modern buildings, such as large office structures, commercial complexes, warehouses and the like, conventionally comprise air handling units into which water or another heat exchange fluid is pumped by which the air is cooled (in summer) or heated (in winter) and circulated to the areas to be conditioned. The heat exchange fluid for cooling is usually circulated through an evaporator/chiller of a refrigeration system which removes heat from the fluid. The heat is delivered to a second heat exchange fluid which circulates through the condenser of the refrigeration system. The second heat exchange fluid may also comprise water or another liquid or may comprise air in an evaporative or air-cooled chiller system. Such systems may also be designed to operate in reverse cycle and act as heat pumps to heat the air to be conditioned. The refrigeration system will, of course, have a cooling/heating capacity appropriate to the capacity of the air conditioning installation. For high capacity installations, such as those incorporated into office buildings and apartments, a high performance cooling system is necessary to be able to handle the expected peak load.

In order to limit the amount of space occupied in a home or residential building by air conditioning and heating systems, it has become desirable to produce residential air conditioning systems that can also serve as a heating system during the winter months and thus provide complete space conditioning for residences in a single unit. In addition, it is necessary for these air conditioning devices to be very efficient, allowing energy expenditure to be reduced in such a way that the savings on the energy bill are significant.

In the state of the art, patent application WO/2004/088219 discloses a refrigeration cycle energy efficiency improvement system composed of: an auxiliary heat exchanger unit for heat exchange between high-pressure liquid refrigerant and low-pressure vapor refrigerant; and a cabinet housing a pressure support value placed at an inlet of an inner pipe of the auxiliary heat exchanger unit, and the pressure of the liquid refrigerant having high pressure condensed in the outdoor heat exchanger being reduced by the pressure support value, maintaining the condensed pressure of the outdoor heat exchanger. The system can be used to accompany with ordinary air cooler and heat pump, etc.

Korean patent application KR100776371 shows a high-efficiency refrigeration system for saving energy and a control method thereof for operating a compressor requiring high power at a low compression ratio by maximally utilizing a heat source of a condenser, thereby increasing the operating efficiency of the compressor. A liquid refrigerant pressure control valve (101) controls a high-pressure liquid refrigerant to the refrigerant supply pressure intended for capacity selection of an expansion valve (8). A gas/liquid heat exchanger (102) removes flash gas generated by decompression of the high-pressure liquid refrigerant from the pressure control valve and performs heat exchange between the low-temperature and low-pressure refrigerant gas and the liquid refrigerant.

The present invention surpasses the energy efficiency of systems known in the art, since it uses water in combination with a direct expansion system to achieve a lowering of the outside air temperature with minimum electrical consumption, while providing it with humidity in a natural way due to the process. This system is capable of achieving this quality of indoor air by influencing the following parameters: lowering the dry temperature of the outside air, total renewal of the indoor air, without recirculating or impoverishing it, providing an optimal indoor relative humidity for health and comfort, ionization of the indoor air, elimination of polluting gases from the interior by overpressure.

The present invention has a direct expansion system installed in an adiabatic environment, where the evaporation battery and the condensation battery never suck in air under the outside temperature conditions, but do so at several degrees below the same by cooling the outside air as many degrees as possible due to its wet bulb depression. This especially increases the thermodynamic performance of the unit, by collecting water from each battery at increasingly lower temperatures in the course of the process that occurs in a "cascade", in such a way that it is capable of providing a very high quality of indoor air with a very high energy efficiency compared to current conventional air conditioning systems, and operating at total renewal of the indoor air, all of this resulting in savings in electricity consumption much higher than conventional air conditioning systems existing today.

DESCRIPTION

DESCRIPTION OF THE DRAWINGS

To complement the description being made and with the aim of helping to better understand the characteristics of the invention, in accordance with a preferred example of its practical implementation, a set of drawings is included as an integral part of said description, in which, for illustrative and non-limiting purposes, the following has been represented:

FIG 1.- It is a schematic view of the air conditioning system of the invention, where inlet arrows of the air drawn from outside into the system are shown and by means of outlet arrows the air flow driven by the system towards the outside. A pre-cooling section is shown that draws air from outside and that includes a water-air thermodynamic exchange battery (1), an adiabatic exchange system (2) and a condensation battery of the direct expansion system (6). Also shown is a cooling section that draws air from outside that includes a water-air thermodynamic exchange battery (4), a direct thermodynamic exchange system (5) and an evaporator battery of the direct expansion system (7).

FIG 2.- It is a perspective view of a preferred embodiment, where a pre-cooling section is shown that draws air from outside and that includes a water-air thermodynamic exchange battery (1) that is fed by the water collected by a water pump (BATI), an adiabatic exchange system (2), a water tank of the pre-cooling section (3) for the water that has not evaporated and that is close to or at the outside wet bulb temperature, in a first phase of the process and fed through said water pump (BAT1) and a condensation battery of the direct expansion system (6); a cooling section that draws air from outside that includes a water-air thermodynamic exchange battery (4), a direct thermodynamic exchange system (5) fed by a water pump (MEDI) that sends the water from the pre-cooling tank (3) and an evaporator battery of the direct expansion system (7); and a direct expansion system (8) installed in an adiabatic environment that is activated from the already reduced temperature section to which the adiabatic system (2) leads, and from there to the temperature required for the propulsion of air to the outside of the system and to the inside of the building.

PREFERRED EMBODIMENT OF THE INVENTION

The present invention discloses a direct expansion system consisting of a unit installed in an adiabatic environment, where the evaporation battery and the condensation battery never draw in air under the outside temperature conditions, but rather do so at several degrees below the same by cooling the outside air as many degrees as possible due to its wet bulb depression of the outside air. The technology used by the device is based on a “cascade” process of cooling the water and air inside it and which occurs between a Pre-Cooling Section and a Cooling Section. The water temperature will be progressively cooled to the different wet bulb temperatures to which the air will be drawn in the successive stages and processes, and which will be progressively lowered below the wet bulb temperature of the air in the different processes. The air temperature will be progressively cooled aided by the cooled water, and it will do so both without enthalpy variation and with enthalpy variation.

The system unit has a sophisticated sensor-based control system, which, depending on the outside air conditions, the inside temperature of the building and the primary air supply temperature of the equipment, the system presents 4 levels of air cooling in order to obtain maximum energy efficiency: Ventilation, Indirect Cooling, Indirect/Direct and Hybridization. In this case, the unit uses the direct expansion system acting as a heat pump, which reverses the cycle depending on whether it needs to supply hot or cold air. When supplying hot air, the cooling section recirculates part of the interior air, and the Pre-cooling Section recirculates the interior renewal air, expelling it to the outside after having recovered its energy in the corresponding direct expansion system coil.

The high energy efficiency air conditioning system for buildings includes an inlet for the flow of aspirated outside air and an outlet for the flow of treated supply air. The high energy efficiency air conditioning system of the present invention comprises: a pre-cooling section whose purpose is to cool water without the use of mechanical compression at the different wet bulb temperatures of the intake air. In addition, it has the function of cooling the condensation battery of the direct expansion system with the cold air resulting from the water cooling process. This pre-cooling section includes a water-air thermodynamic exchange battery (1) fed by the water collected by a water pump (BATI), an adiabatic exchange system (2), a water tank of the pre-cooling section (3) for the water that has not evaporated and that is close to the outside wet bulb temperature fed through said water pump (BATI) and a condensation battery of the direct expansion system (6).

The system also has a cooling section whose purpose is to treat, in the different stages of the air cooling process that it implements, the primary air that will be introduced into the interior of the building to be air-conditioned. It also has the function of cooling the water that will be collected in the water tank (3) of the pre-cooling section by a device created for this purpose, this especially increases the thermodynamic performance of the unit, by collecting water from each battery at increasingly lower temperature in the course of the process that occurs in "cascade", and which will be carried by the water pump specified in the Pre-Cooling Section to the water-air exchange batteries (4), (1). The cold air flow from both Sections can be joined for the air conditioning of the interior of the building under certain circumstances, often doubling the cooling power of the unit. The cooling section also includes a water-air thermodynamic exchange battery (4), a direct thermodynamic exchange system (5) powered by a water pump (MEDI) drawing water from the pre-cooling tank (3) and an evaporator battery of the direct expansion system (7). At the same time, this section also has the function of cooling the outside air before the evaporator battery draws in that air, so as mentioned above, it has a water pump that feeds the adiabatic exchange medium of this section.

The present invention also has a direct expansion system (8) installed in an adiabatic environment that is activated from the already reduced temperature range to which the adiabatic system (2) leads, and from there to the temperature required for the propulsion of the air into the building. The direct expansion system (8) will only come into operation when the demand for air temperature inside the building is such that the conditions of wet bulb depression of the outside air do not allow it to be carried out only with the adiabatic system and it will do so only from the already reduced temperature range to which the adiabatic system leads, and from there (not from the dry temperature of the outside air), to the temperature required for the propulsion of the air into the building.

The air cooling process is developed as noted above by using water cooled to the different wet bulb temperatures of the air throughout the “cascade” process obtained by the design of the invention.

In the first stage of the process, the direct expansion system (8) does not operate, and the air in the outside conditions is drawn in by the Pre-Cooling Section, having previously filtered it, and is passed through a water-air thermodynamic exchange battery (1), which is fed by the water collected by the pump (BATI) of the device strategically located in the water collection tank (3). Thus, the previously filtered air from the outside passes through this water-air exchange battery (1) and is pre-cooled with enthalpy variation approaching the outside wet bulb temperature. Once the outside air has been pre-cooled in this way without the use of refrigerant gases, and having changed its dry and wet temperature conditions by reducing them, it is passed through a direct thermodynamic exchange system (2), this time adiabatic, and is cooled again, this time without enthalpy variation while being ionized and humidified. The water that has not evaporated and that is close to the outside wet bulb temperature at this time is collected at that temperature in the lower tank (3) to, through the aforementioned water pump (BAT1), be driven to the feed of both water-air exchange batteries (1), (4) and the adiabatic thermodynamic exchange medium (2) located in the Pre-Cooling Section of the equipment. Thus, the water pump (BATI) drives the water cooled to the thus obtained outside wet bulb temperature to the water-air thermodynamic exchange battery (4) located in the Cooling section of the equipment.

The air in the outside conditions is previously filtered, and passes to this battery (4) where it is cooled with enthalpy variation by pre-cooling it. Once pre-cooled, it passes to a direct thermodynamic exchange medium (5), which is fed by the water pump (MEDI) sucking from the tank (3), where it is cooled again this time without enthalpy variation. At this point, the temperatures of the air thus obtained, that is, both its dry and humid temperature, have been reduced without the use of a direct expansion system, below the conditions of the dry and humid temperatures of the outside air.

The water that has not evaporated in the exchange system (5) and that is at a lower temperature than the humid outside air, is collected in the water tank (3), to be absorbed by the water pump (BATI) and taken to the hydraulic circuit that first feeds both water-air batteries (1) and (4) of thermodynamic exchange of both the Pre-Cooling and Cooling sections at the same time and independently, and subsequently, when it has been heated, to the thermodynamic exchange medium of the Pre-Cooling section.

The process is repeated in the same way in a constant chain, until reaching a temperature of the supply air in the Cooling Section that is at the temperature of the humid air bubble or even below that of the conditions of the air once treated by the indirect battery (4).

Once this has occurred and the air has been driven through the Cooling Section to the temperature of the humid air at the battery outlet (4) by means of this successive “cascade” process, a second stage of the process described below begins, where the operation of the direct expansion system installed in the unit begins:

The air in the outside conditions passes once more to the Pre-Cooling Section previously filtered, and passes through the water-air thermodynamic exchange battery (1) mentioned in the first stage of the process, which is fed by the water collected in the water collection tank (3) by the pump (BAT1) and this time, is at a temperature much lower than the wet bulb temperature of the outside air. The previously filtered air from the outside passes through this battery (1) and is again pre-cooled with enthalpy variation, but this time close to the wet bulb temperature of the final supply air of the Cooling Section in the last process. The water that could condense this battery (1), will be collected at its bottom by the tank (3), cooling it even more.

The air in the output conditions of the described process is passed again through the thermodynamic exchange system (2), further reducing its dry temperature. The water resulting from the process and which has not evaporated is collected again in the lower tank (3). The air in these conditions is passed this time through the condensation battery of the direct expansion system (6), which is already working. As the temperature of this air is well below the temperature of the outside air, the system achieves significant energy savings that facilitates the cooling process of the unit's supply air, with the help of the direct expansion system (6) with a minimum of electrical consumption. This working air is thrown outside hot and with high humidity. Additionally, in this step the air from inside the building can be returned to the intake of this Pre-Cooling Section, significantly improving the energy efficiency of the unit, since this Section will operate in a recuperative mode of the energy carried by the already cooled air from inside the building without ceasing to operate at a total renewal of this interior air.

The air in the outside conditions is driven to the suction inlet of the Cooling Section, which will be treated by the air-water coil (4) this time with a temperature even lower than the previous process, cooling it once again. The water that may condense in this coil (4) will be collected in the tank (3) from where the pump (BATI) absorbs water.

Under these new conditions, this time it will pass through the evaporator battery of the direct expansion system (7) that is in operation, cooling it with enthalpy variation and having sucked it in temperature conditions much lower than those of the outside air, with the consequent saving in electrical consumption and its corresponding increase in the energy efficiency of the unit object of this invention. The condensation water that is produced will once again be collected in the tank (3) cooling it even more, where the pump (BAT1) sucks it.

It is under these conditions that the air exits the evaporator coil (7) and will pass through the adiabatic cooling medium (5) fed by the water pump (MED1) again to lower its temperature. The non-evaporated water and under the humid air temperature conditions at that point is collected again in the lower tank device of the Pre-cooling Section to be sent to both water-air exchange coils (1) and (4) and subsequently to the evaporative thermodynamic exchange system (2) of the Pre-cooling Section, and repeat the whole process to continue lowering the temperature of the supply air inside the building.

The configuration of the unit can be adapted in its components, such as the position of the water pump suction in the lower tank position in both sections of the unit, or even the elimination of the water-air exchange coil (1), to adapt the performance of the unit to an adjustment in the cost of the unit, while still maintaining high energy efficiency. The direct expansion system can also be eliminated, leaving the equipment only with the operation described for process A and maintaining very high energy efficiency.

Claims (5)

1. - High energy efficiency air conditioning system for buildings that includes an inlet for the flow of aspirated outside air and an outlet for the treated supply air flow and is characterized by comprising: a pre-cooling section that draws air from outside and includes a water-air thermodynamic exchange battery (1) that is fed by water collected by a water pump (BAT1), an adiabatic exchange system (2), a water tank (3) for water that has not evaporated and that is close to the outside wet bulb temperature fed through said water pump (BAT1) and a condensation battery of the direct expansion system (6); a cooling section that draws air from outside and includes a water-air thermodynamic exchange battery (4), a direct thermodynamic exchange system (5) powered by a water pump (MEDI) that sends water from the pre-cooling tank (3) and an evaporator battery of the direct expansion system (7); and a direct expansion system (8) installed in an adiabatic environment that is activated from the already reduced temperature section to which the adiabatic system (2) leads, and from there to the temperature required for the propulsion of air to the outside of the unit and to the inside of the building. 2. - High energy efficiency air conditioning system for buildings that includes an inlet for the flow of aspirated outside air and an outlet for the treated supply air flow according to claim 1 and that is characterized in that the system has a sensorized control system that depends on the conditions of the outside air, the interior temperature of the building and the supply temperature of the primary air of the equipment. 3. - High energy efficiency air conditioning system for buildings that includes an inlet for the flow of aspirated outside air and an outlet for the treated supply air flow according to claim 1 and that is characterized in that the system has 4 levels of air cooling: Ventilation, Indirect Cooling, Indirect/Direct and Hybridization. 4. - High energy efficiency air conditioning system for buildings that includes an inlet for the flow of aspirated outside air and an outlet for the treated supply air flow according to claim 1 and that is characterized in that the direct expansion system (8) is a heat pump, which reverses the cycle depending on whether it needs to supply hot or cold air. 5. - High energy efficiency air conditioning system for buildings that includes an inlet for the flow of aspirated outside air and an outlet for the treated supply air flow according to claim 1 and that is characterized in that when it supplies hot air, the Cooling Section recirculates part of the interior air, and the Pre-cooling Section recirculates the interior renewal air, recovering that energy in the battery of the direct expansion system (8).