A. Overview
The present invention includes a number of aspects all of which have broad and far-reaching application. Although specific embodiments are described herein, the present invention is not to be limited to these specific embodiments. One aspect of the invention relates to the use of a heat extraction and recovery apparatus, method and system for recovering heat that would have been wasted to the atmosphere from a cooling system at an industrial food processing and refrigeration plant for heating water to be used within the plant or wherever a need for heated water exists.
For a better understanding of the invention, one example of how the invention could be made and used will now be described in detail. It is to be understood that this is but one example of the invention.
The context of this exemplary embodiment will be with respect to the refrigeration unit 12 of the type that might be used with a cold storage facility. It would utilize a closed coolant system and conventional refrigeration components and techniques, including a coolant circulation system that includes a condenser coil 20 that extends outside of the housing of the refrigeration unit 12 and through which heated refrigerant gas from refrigeration unit 12 passes. It is to be understood, however, the principles described regarding the system of the exemplary embodiment can be scaled up or down by appropriate modification such as are with one skilled in the art. Additionally, exemplary embodiments could be applied to a single refrigeration unit 12 or apply individually to multiple refrigeration units, all working to refrigerate a single facility.
The present invention contemplates numerous other options in the design and use of the heat extraction and recovery apparatus, method and system.
B. Heat Source from Refrigeration System
C. Heat Extraction Subsystem
A vessel 16 is also provided performing the function of a heat exchanger. Within the vessel 16 is the condenser coil 20, or condenser. Heated refrigerant gas 14 from the refrigeration system 12 travels along the flow pathway 44 from refrigeration system 12 into the vessel 16 at the vessel inlet 18. Inside the vessel 16 the heated refrigerant gas 14 from the refrigeration system 12 travels through the condenser coil 20. The vessel 16 is filled with water from a pressurized water source 30 that flows along the water flow path 44 into a pressure reducer 32 and through the water inlet 28 into the vessel 16. Water from the water source 30 enters the vessel 16 at or near the average water temperature associated with well water, city water, or some other suitable water source (e.g., usually 55°-60° F.). The heat contained in the heated refrigerant gas 14 from the refrigeration system 12 is transferred from the condenser coil 20 to the water 42 in the vessel 16. The heated refrigerant gas 14 from the refrigeration system is subsequently cooled in the condenser coil 20 by transferring heat from the heated refrigerant gas 14 into the water 42 in the vessel 16. The refrigerant gas 14 is then returned to the cooling system 12 through the outlet 22 in the vessel 16.
Positioned on the top of the vessel 16 is a thermostatically controlled valve 26, such as are commercially available. The thermostatically controlled valve 26 has a preset temperature, or the temperature the water in the vessel 16 must reach before the valve 26 opens. Thus, the heated water 42 within the vessel 16 travels out of the vessel 16 through the thermostatically controlled valve 26 positioned at the outlet 40 when the heated water 42 reaches the preset temperature of the thermostatically controlled valve 26. The heated water 42 travels out of the vessel 16 and along the flow path 44 toward the heated water storage tank 36 when the thermostatically controlled valve 26 opens. Heated water 42 moved without the vessel 16 through the thermostatically controlled valve 26 is simultaneously replaced by water from the pressurized water source 30.
D. Controlled Flow
As can be appreciated, the size of vessel 16 can vary according to desire and need. In one version of the exemplary embodiment, relatively low-pressure municipal water at a relatively cool temperature is input into the vessel 16 at or near bottom section of vessel 16. Thermostatically controlled valve 26 either blocks or, in a controlled manner, releases water from the top of vessel 16. Therefore, without any pumps, complex valving, motors, or other complex circuitry or combinations, constant supply relative low-pressure water is available to push water higher up in vessel 16, once heated to a sufficient level as controlled by thermostatically controlled valve 26, out the top of vessel 16. Thus, the hottest water, at the top of vessel 16 where the hottest refrigerant gas within the condenser 20 enters, is always the first to be pushed through valve 26. The vertical placement of condenser coil 20 with optional fins 24 is designed to extract as much heat as possible from condenser coil 20 and then, in a controlled flow manner, remove heated water from vessel 16. This is the “controlled flow” aspect of heat extraction.
For example, if valve 26 does not sense a temperature to open, it would remain closed. Water that is in fill tank 16 would reside there indefinitely. However, once valve 26 opens, water exceeding the opening temperature of valve 26 is thus “recovered” from the refrigeration unit 12. Simultaneously, cooler supply water, by its pressure, enters the vessel 16 and replaces the removed heated water. Thus, valve 26 can operate to let a lot of water out of tank 16 or a little bit, or none. In any event, it is essentially an automatic controlled flow system of extracting heat and recovering heat in water.
The level of pressure of water in most municipal water supplies is well-know. Pressure reducer 32 can further reduce the pressure according to desire and need based on the size and configuration of the system. One of ordinary skill in the art can select the pressure and the necessary pressure reduction. The type and specifications of the valve 26 can furthermore be selected by one of ordinary skill in the art to meet the requirements of the particular system.
In the exemplary embodiment, it is to be understood that the temperature of the heated water released from tank 16 may not be extremely hot. However, it is fairly hot compared to the source water. Depending upon the efficiency of heat extraction and heat exchange, in this example, if the coolant and condenser 20 is 120° F., the heated water out of tank 16 may be close to that temperature. A subtlety of the system is that even though it might not produce very hot water, any heating of source water by the extraction and recovery of heat from the refrigeration system would save energy otherwise needed to heat the water to a hot temperature.
It should further be understood that it is usually desirable that heat insulation be applied to the system. This would include any exposed parts of condenser coil 20, vessel 16, flow paths 44, etc.
Again, it is emphasized, that heat is extracted and sent to a recovery output without moving parts, motors, pumps, electrical equipment and the like. The system would be relatively quiet because of the absence of these types of things.
E. Hot Water Recovery Subsystem
As shown in
Still further, by any number of means such as are well-known in the art, the heat from the heated water in heated water storage tank 36 could be extracted and used for other purposes. For example, heat could be radiated for heating outbuildings or even homes or machinery and the like.
The heated water storage tank 36 has a floating insulator disk that sits atop the water line in the tank 36 to preserve heat within the heated water 38. Additionally, the entire tank 36 would be insulated thermally.
F. Method of Operation
The method of operation has been substantially described above. Relatively cooler water from a suitable water source fills vessel 16. If thermostatically controlled valve 26 senses water in tank 16 has reached certain predetermined temperature by transferring heat from condenser coil 20 into the water 42, the thermostatically controlled valve 26 opens in a controlled flow manner. The heated water in the vessel 16 is pushed out by the water that automatically comes in from the bottom of tank 16 from the pressurized water source until valve 26 closes when the water 42 within the vessel 16 drops below its preset temperature. This process would repeat automatically. Heated water would be sent to hot water storage tank 36 or whatever use is needed or desired. The system basically therefore automatically reloads water into vessel 16 and can operate at a continuously controlled, relatively high-level of filling heated water tank 36 if the parameters are met. On the other hand it could have relatively slow controlled flow of heated water to tank 36. So further, it could release some heated water, valve 26 could close completely, and the system would wait until the water is heated to the preset temperature of the thermostatically controlled valve 26 and remove a little more.
As will be appreciated, the system works a little bit like a cooling system for internal combustion engines of automobiles. The thermostat in an internal combustion engine coolant system regulates the flow of coolant to keep the engine running at an optimal temperature. The thermostat lets out coolant that has exceeded a threshold point so that cooler coolant can come back in and maintain a desired temperature level of the engine. It is important to understand that in this present exemplary embodiment, the thermostatically controlled flow from vessel 16 has, as a significant benefit, a practical and effective way of extracting heat from condenser coil 20 on a continuous basis without the expense of energy costs. This controlled regulated flow actually can help the coolant or refrigeration system 12 operate more efficiently. Regardless of temperature or other environmental conditions, heat is extracted in a regulated manner to try to get as much heat out of the heated refrigerant gas in the condenser coil 20 as possible to return cooler refrigerant gas to the refrigeration system to help it operate efficiently.
But additionally, the combination of heat extraction subsystem and hot water storage subsystem together not only extract heat to help efficient operation of the refrigeration system 12 but recover heat to be put to beneficial use. Again, this is all without moving parts, energy-using machines, complex structure, and the like.
G. Options and Alternatives
As can be appreciated, the invention can take many different configurations. Variations obvious to those skilled in the art will be included within the invention.
For example, as mentioned, the specific components can be selected according to need and desire. The scale of the systems can be designed according to skill of those skilled in the art. Certain optimization techniques can be used. For example, the amount of insulation used with the components and number of coils and fins on the condenser can vary. Practicalities would be taken into account.
The water source 30 may consist of a city water mainline, a well mainline or some other suitable water source. The average ground water temperature is representative of the average temperature of the water coming from the water source 30 whether a city water, well water mainline or some other suitable water source. To prevent heat loss in the system, heat insulation 48 is used on the vessel 16, the flow path 44 between the vessel 16 and the heated water storage tank 36. In addition, heat insulation 48 is used on the flow path 44 of the heated refrigerant gas 14 from the cooling system 12 into the vessel 16 to preserve heat within the heated refrigerant gas 14. Heat insulation is also used on all the other lines to keep the temperature of the water near the temperature of the water from the water source 30.
The heated water storage tank 36 could be centrally located main storage tanks for distribution to other points or could be modular tanks situated near a point of use.
The cooling apparatus, method and system increases heating and cooling efficiencies. Refrigeration systems 12 often waste hot air to the atmosphere in order to cool the refrigerant within the system. The apparatus, method and system uses the waste heat from the cooling system 12 for a beneficial purpose. First, the waste heat from the refrigeration system 12 is used to heat water to the temperature of the heated refrigerant within the refrigeration system 12. The heated water 42 has the potential of reaching the temperature of the heated refrigerant gas of the refrigeration system 12. For example, the heated water 42 in the vessel 16 could reach 120° F. if this is the temperature of the heated refrigerant gas 14 of the cooling system 12. This heated water 42 has many beneficial uses. The heated water 42 could be stored at modular or centrally located points for distribution as needed. Additionally, the heated water 42 could be further heated within a water heater thereby substantially reducing the overall utility requirement to heat the water. For example, if the average water temperature is 60° F. the utility requirement necessary to heat the 60° water within the hot water heater to 180° F. is significantly higher then the utility requirement needed to heat the heated water 42 within the vessel 16 already at a temperature of 120° F. Secondly, the cooling system 12 is able to run more efficiently as the refrigerant is cooled within the vessel 16 to near the temperature of the water from the water source 30. For example, if the average water temperature is 65° F., the refrigerant in the condenser coil 20 is capable of being cooled to 65° F. or the temperature of the water from the water source 30. The controlled flow heat extraction and recovery apparatus, method and system 10 is preferably designed for utilizing waste heat from refrigeration systems used at large cold storage and food processing plants.
The controlled flow heat extraction and recovery apparatus, method and system offers many other numerous advantages. The apparatus, method and system has no pumps, fans, blowers, electronics requirement and/or manual valves. Its operation is nearly inaudible as the thermostatically controlled valve controls the flow of heat extraction and recovery. It also needs little maintenance, supervision and/or calibration and because of its scalability it is economically feasible to extract and recover heat from refrigeration systems of varying BTU capacity. The apparatus, method and system significantly decrease the utility requirement of pre-existing water heating systems as well as cooling systems.
These and other options, variations, are all within the spirit and scope of the invention.