Patent Application
20250003629
The present disclosure relates generally to systems and methods for HVAC (Heating Venting and Air-Conditioning) efficiency. More specifically, the efficiency of existing systems is improved by reutilization of the evaporated liquid from the condenser coils of the HVAC or gathered from other sources in conjunction with a timed sprayer to use this liquid to cool the coils at peak usage times.
HVAC equipment is one of the largest energy users in commercial establishments that serve the public. Gains in efficiency leading to energy savings, even when small in term of percentage, can lead significant monetary savings. Improved efficiency can also improve the lifespan of the equipment.
In typical HVAC systems, heat is absorbed by the evaporator coil. Warm air, drawn in through a vent, blows over a cold evaporator coil raising the refrigerant temperature. This heat is transferred outside, and the refrigerant gets cold. This process is repeated.
The warm and often humid air that is being blown across the cold coil generates moisture which collects on the evaporator coil and drips into a pan. In most typical systems, this condensate is simply drained to the exterior as a waste byproduct.
While there are other systems that offer ways to capture this condensate and reuse it for irrigation or other purposes, the system and method described herein utilizes the liquid to aid in cooling the condenser coils which are part of the refrigeration cycle by reintroducing the condensate, for example by spraying that condensate over the coils.
Further, in many applications the availability of condensate is limited, and systems that look to use the condensate for other operations such as spraying the coils will often have periods when the condensate has been used up and is unavailable.
While some systems have been envisioned for spraying/misting water over condenser coils to improve their efficiency, the control of that spraying and logic behind it is not workable on a large scale. For example, effective control is important as is winterizing to avoid water in exterior lines that can be frozen to make such a solution workable on a large scale.
U.S. Pat. No. 10,605,503 to Shan describes a process by which condensate is used to cool refrigerant. U.S. Pat. No. 7,150,160 to Herbert teaches a method of using the condensate byproduct in a heat exchanger to provide refrigerant pre-cooling. However, these references do not consider monitoring the temperature of the AC unit or other associated temperatures or sensor data to determine when to spray or what rate to spray at, nor do these references consider peak energy usage periods and the costs associated as part of the system in providing the misted condensate as a cooling method.
What is desired then is a system and method that can improve the efficiency of condenser-based cooling systems by reusing condensate to cool the coils of HVAC systems through a sprayer using control systems which receive data on temperature, humidity and other operational data and control inputs to effectively implement a condenser cooling system on a large scale using centralized control.
It is further desired to provide a system and method that can utilize the coil spraying system at optimal times, to ensure that the coil cooling mechanism is used at the most expensive rate times and at high use times when the system is running close to its peak capacity or where outside temperatures are appropriate for use of the condensate.
It is still further desired to provide a system and method that can monitor the level of available condensate or coolant in the tray for use and set a schedule for using the condensate for spraying based on a set of prioritized times.
It is still further desired to provide a system and method that is able to pool condensate collection from multiple HVAC units and other compressor-based systems which may produce condensate as well as other systems such as fuel cells that generate water as a biproduct from their normal operation.
It is still further desired to provide a system and method that can monitor the level of available condensate or coolant in the tray for use and set a schedule for using the condensate for spraying based on a set of prioritized target condenser-based systems using a prioritized schedule for use in each target when multiple such systems are in use.
It is still further desired to provide a system and method that can utilize external sensors such as thermostats and humidity level as well as detecting occupancy to influence the schedule and predict the most appropriate times to utilize the condensate.
It is still further desired to provide a system and method that can utilize machine learning to continue to optimize the schedules and predict both the condensate availability as well as the peak needs for cooling.
It is still further desired to provide a system and method that is aware of the utility billing models and that uses the peak usage period data and rate data to determine the most beneficial time to utilize the condensate for spraying the coils.
It is further desired to provide a system that can be drained remotely and/or winterized to avoid damage to the system in cold periods.
The system monitors condensate levels and correlates these to temperature and humidity functions to establish a baseline of expected condensate availability. This baseline is adjusted based on actual measured condensate levels with the help of sensors which will also account for variables such as normal evaporation and/or possible pan leakage or spills.
The system also monitors outside temperature and occupancy levels to determine ideal use and most appropriate use when occupancy is highest and temperature outside is highest. The system can also leverage external feeds such as temperature forecasts to make predictions.
The system can also be aware of billing data such as peak usage, and rate tables to predict cost information so that it can optimize the spraying of condensate where it can help improve operational efficiency when costs are highest, thus reducing costs. The machine learning can be used to predict condensate availability for these times enduring that we can benefit from the system when it is most needed.
As an example, if only 1 gallon of condensate is generated and will only last for 1 hour of spraying, the system will reserve this condensate, accounting for any evaporation, and keep the spray system off except for the key peak periods where either energy costs are the highest or the condensate will help alleviate peak demand.
If there is sufficient condensate, the system will estimate the condensate need and increasingly utilize it for windows where it will provide the most benefit up to and including using it all the time assuming an unlimited supply,
Once a piece of equipment is put into service, and the expected baseline has been established, a monitoring exercise that accounts for the duty cycle and operational elements in the environment is created. For example, for a HVAC at a fast-food restaurant, the number of people in the room, the temperature is all used to help establish the baseline.
These elements are fed into the system to influence the priorities in addition to the costing data.
The level of the coolant tank is also measured to determine the approximate length of time the system can be cooled, and the volume of water is managed accordingly as are the hours of operation of the pump.
In one configuration, a system for automatically learning and adapting to the condensate availability according to a control input providing the current level of condensate is disclosed. Further, the system monitors and times the use of condensate over time in various conditions of humidity and device operations and is able to thus predict the usage of the available condensate over time. For example, when the condensate level is at ½ of the 10 gallon tank, and we know that at 100 degrees F. there will be some evaporation of the condensate that accompanies the spraying of the condensate, the amount of time the current level of condensate is available to be used can be calculated. We also know that at the current temperature and humidity level, new condensate is added to the pan at a predictable rate when the system is operating. Using these formulas and with machine learning making the formulas more precise we can prioritize the window of spraying based on the available condensate. In an example, say we know that with the rate of evaporation and the rate of new condensate creation we have enough condensate to spray the coils for 2 hours. We can thus start spraying 1 hour before the peak usage period and spray for 1 hour after the peak usage period maximizing the effect of the condensate. If we had 4 hours of spray time, we would start 2 hours before and continue 2 hours after. Further, if we actually had 8 hours of spray, and the peak period lasted 4 hours, we would spray over the whole peak usage time, and look for secondary peaks when to spray. There may be many peak usage periods such as the following: (a) at lunch time there is a rush of people, the ovens are on, the doors are opening and closing, and it's the hottest time of the day. This is the largest peak period of the day which is top priority for the spraying. (b) when the store opens, all the ovens are pre-heated, the grills are pre-heated, the freezer and refrigerator doors are opened to extract food. This may be the secondary peak period in a priority sense. (c) at dinner time, while it is no longer as hot outside, the influx of people, the opening of the door and the added cooking also create a peak which, if there is enough condensate left to accommodate would also merit spraying. The machine learning may also detect other patterns of use. For example, the facility may start a bread baking cycle to prepare bread in the afternoon if the morning sales were good this repeatable pattern may be picked up. Even dynamic monitoring of energy use can help detect increased activity. The system, knowing that it has enough condensate to cover the known peaks, can decide to spray condensate dynamically in the measured and unexpected peak.
An example system comprises: a computer having a storage and coupled to a network, a sensor coupled to the network and associated with the equipment monitoring the level, and software executing on the computer including an expected condensate level over time expected based on equipment use and temperature and humidity readings. The system is provided such that the sensor measures the condensate level when the spray system is in use and out of use transmitting the condensate level data to the computer.
Various objects of the invention are achieved by a fluid distribution system is provided for controlling distribution of fluid to cooling flow over a condenser of an air conditioning, refrigeration or heat pump system. The distribution system includes a controller, one or more sensors and one or more distribution elements configured to distribute fluid, the one or more distribution elements comprising first distributor and a second distributor. The controller is configured to receive sensor data from the one or more sensors and in response to the sensor data, the controller configured to control one or more fluid distribution elements. When the sensor data indicates temperature above a first threshold value, the controller is configured to distribute fluid into cooling flow for the condenser using the first distributor. When the sensor data indicates temperature below a second threshold value, the controller is configured to adjust the second distributor to drain the fluid distribution system.
Additional objects are achieved by a fluid distribution system for controlling distribution of fluid to cooling flow over a condenser of an air conditioning, refrigeration or heat pump system. The distribution system includes a controller, one or more sensors and one or more distribution elements configured to distribute fluid, the one or more distribution elements comprising first distributor. The controller is configured to receive sensor data from the one or more sensors and in response to the sensor data, the controller configured to control one or more fluid distribution elements. When the sensor data indicates temperature above a first threshold value, the controller is configured to distribute fluid into cooling flow for the condenser using the first distributor. When the sensor data indicates temperature below the first threshold value, the controller is configured to not distribute fluid into the cooling flow.
In certain aspects the first distributor includes a pump. In other aspects the second distributor includes a valve. In other aspects a reservoir is arranged to collect condensed fluid from an evaporator, the reservoir arranged to feed the fluid which is distributed into the cooling flow and the second distributor arranged to drain the reservoir. In other aspects at least a first one of the one or more sensors is arranged to measure a temperature at or adjacent the condenser and sensor data from the first one of the one or more sensors is compared to the first threshold to determine if fluid is distributed into the cooling flow. In still other aspects at least a first one of the one or more sensors is arranged to measure an ambient temperature at or adjacent a unit which includes the condenser and sensor data from the first one of the one or more sensors is compared to the first threshold to determine if fluid is distributed into the cooling flow. In yet other aspects the first threshold comprises at least two threshold values associated with different ones of the one or more sensors and further comprising at least a second one of the one or more sensors is arranged to measure an ambient temperature at or adjacent a unit which includes the condenser and sensor data from the first and second ones of the one or more sensors is compared to corresponding threshold values of the first threshold to determine if fluid is distributed into the cooling flow. In yet other aspects the first distributor is configured to spray water into the cooling flow. In yet other aspects the controller is configured to receive a selection indicative of a refrigerant type used in the condenser and one or more values of the first threshold are based on the selection. In certain aspects the controller is configured to adjust a rate of distribution of the fluid based on the sensor data. In other aspects the rate of distribution of the fluid increases when the sensor data indicates an increase in temperature. In yet other aspects a cleaning agent is configured to be distributed with the fluid onto the condenser via at least one of the one or more distribution elements.
Other aspects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.
Referring now to the drawings, wherein like reference numerals designate corresponding structure throughout the views. The following examples are presented to further illustrate and explain the present invention and should not be taken as limiting in any regard.
The vapor-compression refrigeration cycle is the pattern cycle for the great majority of commercially available refrigeration systems. This thermal transfer cycle is customarily accomplished by a compressor, condenser, throttling device and evaporator connected in serial fluid communication with one another. The system is charged with refrigerant, which circulates through each of the components. More particularly, the refrigerant of the system circulates through each of the components to remove heat from the evaporator and transfer heat to the condenser. The compressor compresses the refrigerant from a low-pressure superheated vapor state to a high-pressure superheated vapor state thereby increasing the temperature, enthalpy and pressure of the refrigerant. A superheated vapor is a vapor that has been heated above its boiling point temperature. It leaves the compressor and enters the condenser as a vapor at some elevated pressure where the refrigerant is condensed as a result of the heat transfer to ambient air. The refrigerant then flows through the condenser condensing the refrigerant at a substantially constant pressure. The refrigerant then leaves the condenser and the pressure of the refrigerant is decreased as it flows through the expansion valve, resulting in a temperature drop. The refrigerant temperature then increases through the evaporator as a result of heat transfer from the refrigerated space. This vapor then enters the compressor to complete the cycle.
A system for cooling that sprays condensate over the hot coils to lower the temperature and improve the efficiency of the HVAC unit during peak times will provide a distinct advantage over existing systems. In doing so, the HVAC does not have to run as long to reach the target temperature, and the HVAC runs more efficiently as the coils are cooler and provide better cooling. Particularly, the challenge with refrigerant systems, especially air conditioners is that when the refrigerant leaves the compressor and enters the condenser as a vapor at some elevated pressure, the ability to then condense the refrigerant and provide heat transfer to ambient air is dependent largely on the temperature of the ambient air, with hot temperatures providing for less efficient cooling and forcing the cooling unit to work harder to provide e.g. air conditioned spaces in the building. The head pressure of the refrigerant should be about 325-375 psi in some examples, e.g. with R-410 refrigerant. However, if the ambient air is too hot, this pressure will increase and the system will then have to work harder. At the same time, if the condenser is cooled off too much, the head pressure can get too low and the compressor then is being fed refrigerant in a liquid state and not a gaseous state, causing operational problems. Depending on the refrigerant used in the system, the ideal pressure may be different. Since the systems are closed loops, the temperature and pressure are proportionate and the pressure can be inferred or approximated when knowing the temperature of the refrigerant or something indicative of refrigerant temperature (e.g. the temperature of the condenser). However, since the evaporator will produce water as a byproduct, that water can be misted into the cooling flow from the fan through the condenser so that the water can provide added ability to absorb heat, particularly in phase change from a fine liquid mist to steam, or simply by allowing the liquid to absorb heat at a rate that the ambient air alone could not.
Referring to
The pump 14 may be variable in that it operates at a variable speed that can increase or decrease the rate of fluid sprayed through the sprayer 10 into the cooling flow. Particularly, at higher temperatures measured by one or more of the sensors 18, 20, 22, 24, the pump 14 may be operated at higher speeds by the controller to provide more fluid flow to the sprayer 10. In this case, since the AC unit is running more frequently and a known volume of air is being cooled, the rate of condensate production can be determined or approximated. For example, sensor 20 may include multiple sensor types, including e.g. humidity. Thus, depending on the temperature and humidity, the controller can determine the rate at which the evaporator 2 will produce condensate liquid and then spray water via the sprayer 10 at an appropriate rate. It may be preferable to use the condensate produced at evaporator for spraying as condensate temperature may be relatively low as compared to a normal water supply.
A water supply would require plumbing lines run to the refrigerator/AC unit, resulting in a more complex installation. Nonetheless, if the condensate produced is insufficient, a supply line 13 may be provided to provide water to the sprayer system and/or to supplement the reservoir. This may be necessary in climates that are both hot and dry. A valve 15 may be controllable by the controller to allow external water from the water supply into the reservoir 3 as needed. The control of the valve may be based on. Float sensor 5 or another type of fluid level sensor may be in communication with the controller 12 and may be used to monitor the water level in the reservoir for purposes of the controller controlling valve 15 to supplement/fill the reservoir 13 and/or for purposes of controlling the pump 14 and the resulting rate of spray of water through the sprayer 10.
The float sensor 5 may also include a temperature sensor to measure the temperature of the condensate in the reservoir 3. The temperature of the condensate in the reservoir 3 may further be used by the controller to determine the rate at which the pump 14 is activated in order to maintain optimal temperature of the condenser 6 as measured by sensor 18 or to maintain optimal temperature of one or more of the lines as measured by sensors 22, 24, and/or 26. Furthermore, the controller can be connected to additional sensors 28 which may be positioned in the space that is being cooled/conditioned and may measure various internal environmental parameters. This may be an existing thermostat, humidity and/or occupancy sensor/light sensor, or a sensor array with a combination of these sensors or other known environmental sensors.
The controller 12 may include a wireless connection 9 such as radio, wifi, Bluetooth or other wireless data connection. This may allow the sensors shown to be connected wirelessely instead of hardwired. The sensor data obtained from the sensors shown can be communicated to a central computer which can monitor and adjust the controller's control logic software.
For example, in situations where the reservoir 3 does not include an external water connection 13, conserving the water for use in peak times may be desirable and this may further be determined based on the electricity rate.
Referring to
Usage priorities 460 and a prioritized schedule 465 are developed and form the baseline of when to turn on the spraying systems.
The system then monitors outside temperature and humidity 470 as well as the condensate level 475 through the various sensors described herein (see. E.g.
If sufficient condensate does not exist (i.e. condensate is insufficient), a peak schedule 485 is used to selectively spray the prioritized HVACs at the prioritized time periods based on the availability and expected duration of spray time. This spraying is used most sparingly—spraying only when energy costs are the highest and/or utilization is closest to peak demand.
If sufficient condensate exists, a non-peak program 490 is followed where additional spray windows are used for non-peak times. This algorithm adds windows based on the availability up to an including keeping the sprayers on at all times assuming sufficient condensate.
The monitoring continues 495, and the system adapts its predictions based on sensor information such as whether the condensate has been depleted or if excess condensate remains.
Referring to
Referring to
The efficiency gains improve the lifespan of the HVAC, get the room to the desired temperature faster in a cost effective manner as the condensate is created by the system or other systems under normal operation. By employing temperature sensors and thermostats as well as timers, the use of the condensate can be optimally used by targeting the most lucrative periods where savings will yield the best results or efficiency will provide the most comfort in the use of the equipment. For example, especially in systems that do not have an external water supply, when peak evening rates exist and it is expected to be relatively warm overnight, it may be preferable to conserve the condensate at times when the system would normally call for condensate spraying based on the temperature. However, running the AC unit in a less efficient manner at a lower rate in order to save the condensate for use when rates increase may be overall less expensive, depending on the amount of condensate available and the expected ambient temperatures and demand for AC and the resulting supply of condensate during peak rate times. Additionally, the reservoir 3 may be provided with a cleaning solution 300 which is water soluble at a relatively slow rate. This cleaning solution may provide light cleaning by capturing and/or assisting in removal of dust, dirt and debris from the condenser, thus increasing its efficiency and reducing the need for frequent cleanings of the condenser.
In energy billing, there are important cost factors to consider such as peak energy usage, cost of energy at peak times and the occupancy of the space being cooled. For example, large savings can be obtained by reducing peak usage-based demand charges which may affect energy bills in a long-lasting fashion. Using any energy saving solutions at times that can offer maximal cost benefits is paramount to getting the most of out of the efficiencies offered by such systems.
While many of the examples above have been made in connection with cooling equipment for an HVAC system, similar factors can be considered when applied to various different types of equipment including freezers and refrigerators. Any compressor-based cooling system can benefit from the example system as described herein to save energy costs.
Further, while the examples described herein primarily focus on the condensate reuse from the same HVAC which is being cooled, larger deployments can make use of pooled condensate reservoirs applying the timing and spray of the reservoir to those systems that need it the most and at the most opportune time. Further, technologies such as fuel cells or other clean water generating devices can also contribute to the condensate pool.
It will be understood by those of skill in the art that while examples using HVAC are utilized, the same system can be adapted and used for any compressor-based systems, and any systems that can gain efficiency by utilizing a spray of water.
While the invention is susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. Is should be understood however that the invention is not to be limited to the particular forms or methods or embodiments disclosed.
| Number | Date | Country | |
|---|---|---|---|
| 63524345 | Jun 2023 | US |
