Self Contained ICE-Maker Energy Efficiency Boosting System

The present invention relates to systems and methods related to improving the energy efficiency of compressor-based restaurant equipment, more specifically ice-making equipment. Various methods or reutilizing the cold wastewater generated from the ice-making process are proposed including utilizing this wastewater to cool the exhaust air of the icemaker, to cool the input air of the ice maker before reaching the coils, as well as using the wastewater to cool the input water to the icemaking process. Further, a control system to manage and select between the approaches based on seasonality and machine learned historical performance is presented.

Quick Serve Restaurants (QSRs) are generally run in relatively tight spaces with an abundance of equipment positioned in close proximity to each other within the space. A great deal of time and effort are put into determining the most efficient layout of this equipment to generate the maximum amount of food in the most expeditious manner possible. This has typically led to equipment being tightly packed in and around the food cooking and preparation area. Even larger restaurants with large seating areas may have the same constraints within their kitchens.

Much of the equipment used to store, prepare, and cook food generates a considerable amount of heat. For example, a refrigerator or freezer operates on the principle of removing heat from inside the equipment and exhausting this heat, usually right into the space adjacent to the equipment and into the tightly packed food preparation area. This hot exhaust is uncomfortable to those working in the space. It also affects other equipment causing it to be less efficient. The HVAC units must work harder to cool the space, and even then, hot spots in tightly packed areas are difficult to address with typical HVAC ducting and ventilation.

While stoves and grills are provided with hoods that function to exhaust smoke and other biproducts to the exterior of the building, these cooking areas still create ambient heat which affects the space within which they operate. Other restaurant equipment, such as food warmers, heating lamps, ovens and toaster ovens also contribute to the release of heat into the surrounding workspace.

During cold winter months, all this release of heat may function to warm the space, and even to reduce the need for heating by the HVAC, raising the temperature in the space to a comfortable level. Often, however, the confines of the hot kitchen area still get so hot that they must be cooled even in the winter months due to the tightly packed equipment and the resultant heat from cooking that is generated.

During the hot summer months, the additional heat can add a significant load to the HVAC equipment. Lowering the temperature in the kitchen area to a comfortable level and reducing hot spots in the working area is also much more challenging.

While the main cooking area of the restaurant may be the most affected by this phenomenon, even self-serve drink stations with ice makers and other congregations of equipment suffer from the same effects.

Cooling equipment, such as ice makers, ice-cream makers, frosty or snow-cone makers, etc. are some of the largest energy users in a QSR and some of the largest heat generators. Further, these are used the most during hot summer months when cooling the space is the most challenging and takes the most energy due to an already large temperature differential with the outside air and the desired inside temperature. To maintain the cold temperatures required inside these types of equipment to make the ice, compressors or cooling systems within the machines expel a significant amount of heat into the working space by means of fans. Each of these pieces of equipment can expel air at a temperature that can exceed 120° F.

Due to the limited space available, there is usually insufficient areas to to run ductwork to extract the hot air expelled from these units. In addition, the equipment in question may be relocated or may be reconfigured making any form of venting difficult if not impractical.

As a result of the above, the ambient temperature of the surrounding working space rises causing the HVAC equipment to cycle on to compensate. This means that energy is being used to cool the inside of the equipment, which causes the space to be heated, which in turn requires still more energy to be used removing that resultant heat from the space. This very inefficient system has been the norm for many decades.

Energy costs continue to climb. As electricity rates climb, the need to eliminate unnecessary energy equipment loading and reduce the impact of equipment on HVAC loads is even more important. One challenge that QSRs face is that the footprint of the space is relatively small, and as stated above, the amount and location of the equipment may be predefined and limited due to the space constraints and process engineering requirements. In some circumstances, new machines are required to support new products or offerings, and these must be added into an already tight configuration.

Further, rising energy costs and growing environmental concerns have led to an increased awareness and desire to reduce energy consumption. Energy efficiency has grown beyond a simple number on a spreadsheet than a successful restaurant can write-off as an energy expense on a spreadsheet. Concern for the environmental impact has become an important driver towards rooting out and identifying energy inefficiencies. Government incentives also play a role, but conscientious business owners are looking for energy efficient solutions and implementing these when these are available.

Various systems have been proposed in the past with limited success for removing hot exhaust air from various appliances. For example, U.S. Pat. No. 7,500,911 to Johnson, describes a system for removing hot air via ducts and fans from racks of equipment. The system includes a fan unit preferably configured to serve as a back door of an equipment rack or enclosure and configured to provide access to an interior of the rack or enclosure. The fan unit provides multiple fans coupled to internal exhaust ducts that are arranged to draw and to remove exhaust air vented from rack-mounted equipment. The fan unit is further configured to vent exhaust air to an area external to a rack or enclosure, such as an external exhaust duct or plenum. Removal of hot and warm exhaust air vented from rack-mounted equipment enables the equipment to operate effectively, drawing sufficient amounts of cooling air to meet its cooling requirements. The fan unit is constructed for portability and for easy attachment to and removal from a rack or enclosure, providing flexibility in handling equipment exhaust needs.

Chinese patent CN201041443Y describes a system for reusing the runoff water from the evaporator coils for re-circulation in future ice making processes. However, there are significant food safety concerns in doing so.

Therefore, a need exists for a better solution for avoiding the addition of hot air into rooms where such hot air is created by ice-making machines in tight spaces. Further, a system that can reutilize the generated cold-water runoff with little to no additional energy burden would be ideal to efficiently capture and transport heat from equipment positioned in a QSR.

When looking at icemakers in particular, a byproduct is a large amount of runoff water which is typically drained. This water is relatively cold, near freezing, and is generated when the system sprays water on ultra-cold plates to make the ice. While icemakers come in various forms, in general there is an ice making cycle and a harvesting cycle. During the ice-making cycle, water is sprayed on or otherwise contacted with cold surfaces and ice begins to form on what are typically metal plates, usually stainless-steel. As more water is sprayed, the ice thickens. When the ice reaches a given thickness or after an elapsed time or other measure such as weight or visual sensing, the process switches to harvesting. The harvesting cycle warms the plate creating a thin layer of water under the newly formed ice allowing the ice to fall off the plate and into a collection tray where the ice is ready for consumption. This process then repeats itself to the extent additional ice is needed. This is usually at an interval of about 10-20 minutes.

In a typical commercial ice-machine, 3-5 gallons of near freezing water are generated in each ice making cycle. This wastewater is usually just run down the drain. This near freezing water can have many secondary uses as will be described herein. Particularly, waste water from the ice making process is fed through one or more heat exchangers to cool other fluid(s) which are associated with the ice making process such as new water to freeze, incoming air and/or exhaust air. This water left over from the ice making process can be used as a coolant within a cooling system for the hot air that is expelled by the ice maker, it can be used to cool in incoming air that flows over the compressor coils, and/or it can be used to precool the water flowing into the icemaking process. All of these provide an energy efficiency boost to the icemaker or to the overall room efficiency and can be incorporated into an existing icemaker with minimal effort. Further, the incorporation of intelligent management through a controller can prioritize and adjust the flowrates and utilization of the system to maximize efficiency based on external factors such as seasonality, historical savings or efficiency, environmental conditions, and utility rates.

Accordingly, it is desired to provide a system and method that captures and transports the cold run-off water from the ice-making process and uses it to reduce the heat of the exhaust air, to cool the air blowing over the coils of the compressor, and/or to cool the input water feeding the ice making process are all ways an icemaker can be made more efficient.

It is an object of the present invention to provide a method of cooling the expelled air from the vents of restaurant refrigeration equipment in an efficient manner. This allows for this air to enter the environment in a cooled state thus reducing the ambient heat that can impact the surrounding temperature and have a negative impact on HVAC systems. Further, such a system eliminates the need for expensive and bulky duct work to exhaust the air out of the space. It also makes the movement and adjustment of equipment easier as there are no bulky and immovable vents to contend with.

It is further desired to provide a system and method for capturing the wastewater in a reservoir and providing a level sensor, and a pump that feeds water into a heat exchanger with a thermostat and controllable valve to manage the water flow. The cold water is pumped to one or more heat exchangers and these heat exchangers are installed in front of the vent where the hot air is exiting, or where warm air is entering to blow over the coils.

It is further desired to provide a heat exchanger used to transport the water input to the ice making process and passing the water through a heat exchanger placed in a bin of collected cold water from the ice making process.

It is further contemplated that one could use multiple heat exchangers in the same system, combining the above approaches as the ice water cools. As an example, the water coming from the utility may be at 60 degrees, and cold ice water at 35 or 40 degrees can help to cool this water. Even after the ice maker run-off water used in this process that is collected in the bin through which the tap water passes warms up to, say 50 degrees, that 50 degree water is still cold enough to provide cooling to the input air which comes in at 75-85 degrees and blows across the coils. Similarly, even after this second heat exchanger warms up the water further, for example to 60 degrees, that water can be used in a different heat exchanger to cool the exhaust air which may be coming out at well over 100 degrees.

Of course, maximum efficiency is used by providing the coldest water possible to each system, if multiple systems are employed and while a limited supply of run off water can be used in series as described above, it is also possible to utilize a system of valves to send the cold water directly to each heat exchanger.

Accordingly, a system comprising a wastewater reservoir, one or more heat exchange devices coupled to a pump via a supply line, which are in turn connected to the reservoir, along with thermostats to measure the water temperature and controllable valves to manage the water flow into the heat exchangers is described.

In one configuration, a system for capturing and transporting heat from equipment is provided, comprising a detachable heat exchanger detachably connected to a first equipment, the detachable heat exchanger comprising an internal coil structure, a first connection port adapted to receive a quick-connect hose connector, the first connection port connected to a first end of the internal coil structure, and a second connection port adapted to receive a quick-connect hose connector, the second connection port connected to a second end of the internal coil structure. The system further comprises a pump including a supply pipe extending from the pump to the first connection port, and a heat exchange device including a supply pipe extending from the heat exchange device to the pump, and a return pipe extending from the first equipment to the heat exchange device. The system is provided such that the supply pipes that extend from the heat exchange device to the pump, and from the pump to the first connection port which comprises a supply loop, and the return pipe that extends from the second connection port to the heat exchange device comprises a return loop. The system is still further provided such that heated air exhausted by the first equipment is directed into and captured by the detachable heat exchanger, and the captured heat is transported to the heat exchange device.

In another configuration, a system for capturing and transporting heat from equipment is provided comprising a detachable heat exchanger detachably connected to a first equipment, the detachable heat exchanger comprising: an internal coil structure, a first connection port adapted to receive a quick-connect hose connector, the first connection port connected to a first end of the internal coil structure, and a second connection port adapted to receive a quick-connect hose connector, the second connection port connected to a second end of the internal coil structure. The system further comprises a pump including a supply pipe extending from said pump to said first connection port, and a heat exchange device including a supply pipe extending from said heat exchange device to said pump, and a return pipe extending from said first equipment to said heat exchange device. The system is provided such that heated air exhausted by the first equipment is directed into and captured by the detachable heat exchanger, and the captured heat is transported to the heat exchange device.

In a further configuration a system is provided for capturing and transporting heat from equipment. A heat exchanger is configured to be positioned in or adjacent the housing of an icemaker. A reservoir is configured to receive water from the ice maker which water is excess water which was directed at a cooling plate for making ice in the ice maker. The heat exchanger is configured to receive the water to cool the heat exchanger and the heat exchanger cools a second fluid which passes the heat exchanger, wherein the second fluid is fluid which enters the housing of the ice maker.

In certain aspects the second fluid is incoming water for making ice and in further aspects the second fluid is air which is urged by a fan over a heated portion of the ice maker to cool the heated portion of the ice maker. In yet other aspects the heated portion of the ice maker is a condenser of the ice maker. In still other aspects the heat exchanger is positioned such that heated air passing through the housing which is expelled by the ice maker is cooled by the heat exchanger. In yet other aspects the heat exchanger is positioned to cool air which is urged by a fan passed the heat exchanger and exhausted out of the housing. In yet other aspects a controller is provided with a temperature sensor coupled to the controller. The temperature sensor is provided to measure either the air exhausted by the first equipment or the temperature of the fluid in the return pipe coupled to the second connection port. The variable speed is pump coupled to the controller and the controller comprises a setpoint and when a measured temperature deviates from the setpoint, said controller adjust the speed of the variable speed pump and also adjusts electronically controlled valves to adjust flow of the water.

In certain aspects the heat exchanger comprises at least two heat exchangers, at a first one of the two heat exchangers is configured to cool the second fluid which is incoming water for making ice and the second of the at least two heat exchangers is configured to cool a third fluid which passes through the heat exchanger, wherein the third fluid is fluid which enters the housing of the ice maker and the third fluid is air. In certain aspects the second of the at least two heat exchangers is positioned such that heated air passing through the housing which is cooled by the heat exchanger and expelled out the housing. In still other aspects the second of the at least two heat exchangers is positioned downstream of a fan which blows the third fluid over a condenser if the ice maker. In still other aspects the controller controls one or more pumps, each of the one or more pumps urges the water through one of the at least two heat exchangers. In further aspects the controller receives status data from a heating unit, a venilation unit and/or a cooling unit associated with a space where the ice maker is positioned and the controller selectively operates the one or more pumps based on the status data.

In other aspects a system for capturing and transporting heat from equipment is provided including an ice maker having a housing and a heat exchanger configured to be positioned in the housing. A reservoir is configured to receive water from the ice maker which water was directed at a cooling plate for making ice in the ice maker. The heat exchanger is configured to receive the water from the reservoir to cool the heat exchanger and the heat exchanger cools a second fluid which passes through the heat exchanger. The second fluid is fluid which enters the housing of the ice maker.

In certain aspects the second fluid is incoming water for making ice. In other aspects the second fluid is air which is urged by a fan over a heated portion of the ice maker to cool the heated portion of the ice maker. In certain aspects the heated portion of the ice maker is a condenser of the ice maker. In other aspects the heat exchanger is positioned such that heated air passing through the housing which is cooled by the heat exchanger and expelled out the housing. In still other aspects the heat exchanger is positioned to cool air which is urged by a fan passed the heat exchanger and exhausted out of the housing.

In other aspects a method is provided for capturing and transporting heat from equipment and includes one or more of the steps of: installing a heat exchanger in or adjacent a housing of an ice maker; connecting the heat exchanger to a water source which collects water which was directed at a cooling plate for making ice in the ice maker such that the water from the water sources passes through and cools the heat exchanger; and positioning the heat exchanger and/or a source of second fluid such that the heat exchanger cools the second fluid which passes the heat exchanger, wherein the second fluid is fluid which enters the housing of the ice maker.

In certain aspects the second fluid is incoming water for making ice. In other aspects the second fluid is air which is urged by a fan over a heated portion of the ice maker to cool the heated portion of the ice maker. In still other aspects the heated portion of the ice maker is a condenser of the ice maker. In yet other aspects the heat exchanger is positioned such that the second fluid is heated air passing through the housing which heated air is cooled by the heat exchanger and expelled out of the housing.

Adaptations of the above for providing cooling of the input air into the ice maker to cool the compressor coils and to provide cooling to the input water for the ice making process as well as cooling for the air exhausted from the ice maker used to cool the condenser.

While the examples above primarily utilize the wastewater from the ice making process, the cold water may also be fed by other equipment that uses water to generate cooling such as shaved ice machines and slushy machines and the like. In some circumstances it may be possible to provide an alternate cold water source or a secondary cold water source such as a cooling tower, or by passing the water through the ground using geothermal systems, or any other means by which the liquid can be sufficiently cooled to provide a large temperature differential to extract the heat from the air passing by the coils of the heat exchanger.

Other objects of the invention and its features and advantages will become more apparent from consideration of the following drawings and accompanying detailed description.

Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views.

shows a commercial/industrial ice making machine and depicts the ice making process in general. While a commercial/industrial machine is shown, it is understood that smaller ice makers may benefit from the disclosure herein, including those in drink machines, refrigerators and other situations which cold water is generated but normally discarded. Input water from the water utilityis transported to sprayersand sprayed onto a cold surface. After some time, this water builds up on the cold surfaceas ice and the surfaceis briefly heated to cause the ice to fall down into a bin below (not shown). As the water is sprayed onto the cold surface, some of the water does not stick but runs off into a collection bin. This water is then drainedor may be recirculated during a particular ice making process and then finally drained once ice making is complete for and the system will transition to heating briefly to harvest the ice from the plates.

shows a typical ice making process. The internal structure within the housingof the ice maker is shown. Input water from the water utilityis transported to sprayersand sprayed onto a cold surface. After some time, this water builds up on the cold surfaceas ice and the surfaceis briefly heated to cause the ice to falloff into a bin. The resultant iceis then stored in binand a level sensoris used to stop and start the process when the bin is full. As the water is sprayed onto the cold surface, some of the water does not stick but runs off into a collection bin. This water is then drainedor recirculated and drained as described above.

provides further detail of the ice making machine with the enhancements introduced for use of the cold water. The ice making processis made up of cooling platesand a sprayer. Water is intermittently sprayed onto the platesallowing ice to build up. While ice is forming, some of the sprayed water maymay collect in the upper tank and the level thereof may be determined by a float sensor(or other level sensor). After the ice has formed, a harvest cycle is started whereby the platesare slightly warmed causing a layer of water to form under the ice, and the ice falls into a collection tray. While the ice-making process is more complex, for the sake of explaining the enhancements within the above basic explanation will suffice. Throughout the ice-making process, the sprayeralso creates run-off waterwhich builds up in a reservoir. When full, or when the ice making process completes and goes into harvest mode, a valveis opened and the waterruns down into a secondary collection tank. As an alternative, the valvemay be plumbed such that the water is run through one of the heat exchanger coils directly in order to reduce the need for that water to be pumped through the exchanger. In the tank, a float sensor(or other level sensor) is present to detect the water level and a thermostatto detect the water temperature. A pumpis used to flow waterto a coilwhich is placed in front of the exhaust fan, thus placing a heat exchanger filled with near-freezing water in front of the hot exhaust air coming from the coil. Another thermostatis placed by the coilwith a valveallowing the water from the coil to exit to the drain valve.

Cold water from the reservoiris thus pumped to the heat exchanger coiluntil it warms up beyond a threshold and is then drained and replaced with fresh cold water from the reservoir. Meanwhile as the ice making process continues, additional water is supplied to the reservoir. If the reservoir floatdetects the reservoir is too full, the system will drain water through the coil allowing water to pass through regardless of the temperature.

Turning now towe see an adaptation of the icemaker efficiency system applied to cooling input water to the ice making process. An additional tank′ is provided below the ice maker process tank containing water(see). Or alternately the plumbing/additions shown inmay be applied to the tank of. A heat exchanger coilis provided so that input watercoming from the water utility (or other supply for ice making) is pumpedthrough the coil. Valveis provided for moving water from tankinto tank′ as needed. Tank′ also has a float sensor′ and thermostat (which may be integrated with the float sensor or a separate sensor) in order to measure water level and temperature so that it can be determined if valveshould be opened to move the water into another tank (e.g.) or to the drain. Pump′ circulates the water in tank′ through the coil.

If the water level/′ as measured by sensor/′ shows sufficient water to continue spraying, the ice maker may continue to use that water until sufficient ice has formed, thus reducing the need for utility supplied water (which is usually warmer) to be introduced into the system. However, when utility water is needed for purposes of ice making, it may be beneficial to recirculate some of the stored water through the heat exchanger coilto pre-cool that incoming warmer water.

shows an icemaker with alternate configuration where the heat exchanger coilis placed on the back of the unit cooling the input air drawn in by fanwhich is generally directed over the compressor coils and out an exit vent.

shows another view of where the heat exchanger coil icemaker with alternate configuration where the heat exchanger coilis placed next to the condenser coilsthe back of the unit cooling and the input air pathand output air pathfor illustration purposes.

show various embodiments with different tanks and coil configurations. It is understood that these may be stand alone systems or that the systems may all be combined into one with a heat exchanger located both before and after the fanand the coil/heat exchangerprovided for cooling incoming water. It is understood that some or all the sensors/thermostats disclosed herein may be and preferably are connected to the controller and that the various valves and pumps or other devices to implement the controls may also be connected to the controller which will manage operation of and use of the cold water in connection with the heat exchanger.

It is understood that configurations of icemakers may vary and the application of one or more of these systems, combinations thereof can all be considered either individually or combined for the ice maker at hand.

shows an overview of the logic in a block diagram depicting the valve control and energy saving process.

The ice making process beginswith the sprayers spraying water onto the cold surfaces and water running off into the first storage bin as excess water is accumulated during ice making. The level of this first reservoir is checkedand if fullthe water is drainedinto a storage tank which may be insulated to keep the water at the cold temperature desired.

The level of the storage tank is also monitoredand if this tank becomes full, water is pumpedthrough the exchanger coil and drained to avoid overfilling the tank or moved to a different holding tank which feeds one of the other coils/heat exchangers described herein.