High lift, low flow water heating system

Abstract

A geothermally-based system for creating hot water, the system including a ground source of water, a heat pump for creating heated water, and at least one storage tank coupled to the heat pump and the ground source. At least one storage tank initially contains cold water from the cold water supply to be supplied to the heat pump at a low flow rate to achieve high lift, which significantly improves the efficiency of the heat pump and / or can significantly increase the outlet load temperature of water heated by the heat pump, even while operating the heat pump at its rated efficiency. Placing the storage tanks in series at the low flow rate further maintains stratification of hot and cold water contained within the storage tanks. The system further includes controls to stabilize the system during variable periods of hot water demand by monitoring the temperature and / or volume of water in the heat pump and the cold storage tank.

Description

[0001] HIGH LIFT, LOW FLOW WATER HEATING SYSTEM

[0002] Cross Reference to Related Application

[0003] This application claims priority to United States Patent Application Serial No. 63 / 705,368, filed October 9, 2024, under relevant portions of 35 USC §119 and 35 USC §120, and in which the noted priority document is incorporated by reference in its entirety.

[0004] Technical Field

[0005] This application generally relates to the field of water heating systems and more specifically to a high lift, low flow geothermally-based water heating system. The novel system utilizes serial piping between storage tanks and effective controls, while maintaining a storage of cold water in at least one of the storage tanks for purposes of more effectively and efficiently heating water. The herein described system and methodology can be employed in residential and commercial settings, such as, but not limited to single or multi-unit residential and commercial buildings having a number of tenants or customers.

[0006] Background

[0007] An original design for a typical or conventional high capacity / high load domestic hot water system for structures such as apartment buildings having a large number of tenants includes piping multiple tanks in parallel to increase hot water storage capacity covering peak load scenarios.

[0008] In addition, due to lesser capacity of modern heat pump system (but significantly higher efficiencies), the need for storage tanks is even more pronounced. However, heat pumps traditionally require a large amount of water flow to operate in a stable fashion, with the water only remaining in the heat pump sufficiently long enough to be heated up by about 10 degrees F.

[0009] This high volume / high velocity flow of the afore mentioned heating systems usually results in mixing the hot water stored in the tank with the cold make up water entering the tank on the bottom, resulting in immediately cooling down the storage tanks, which was observed under high loads. A typical and previously known piping arrangement for a residential hot water heating system is shown in FIGS. 1(a) and 1(b). This traditional system includes a heat pump 10 including a circulation pump 14 connected to the load side thereof wherein heated water from the heat pump is circulated to a series of storage tanks 20, 22, 24, each of the foregoing tanks being arranged in parallel relation to one another and further coupled to an electric buffer device 30, the purpose of which is conventionally known and which is not a part of the present invention. This traditional parallel piping, high flow system design resulted in the electric tank 30 turning on and having to supplement the hot water temperature to the building or other structure. Thus, a low flow would be desirable in order to not mix down the parallel storage tanks 20, 22, 24 with incoming cold water and to not disturb the defined stratification with stored heated water being in an upper or top portion 27 of each of the parallel arranged storage tanks and cold make up water being in the lower portion 25, as shown, particularly in FIG. 1(b).

[0010] FIG. 1(c) similarly illustrates another previously known heating system that includes multiple heat pumps 10A, 10B, with the series of storage tanks 20, 22, 24 also being disposed in parallel relation to one another. As with the system shown in FIGS. 1(a) and 1 (b), this heating system also utilizes high flow rates with the storage tanks providing additional hot water storage. It should be noted that the source side connection of the heat pump to the ground source is not shown in FIGS. 1(a), 1(b) and 1(c), though these latter connections are fairly well known and do not themselves form a part of the present inventive teachings.

[0011] Accordingly, there is a long felt and prevailing need in the field to improve the design and efficiencies of domestic water heating systems, including those reliant on geothermal heating.

[0012] Brief Description

[0013] Therefore and in accordance with at least one aspect of the teachings provided herein, there is provided a method for significantly increasing the functionality of a heat pump, the method comprising the steps of supplying cold water from a cold water storage source to the heat pump; and supplying the cold water through the heat pump at a low flow rate. The foregoing creates high lift while reducing energy consumption, which can create significantly higher efficiency of the heat pump.

[0014] In accordance with yet another embodiment, the heat pump can be operated at its usual efficiency, wherein the supplying of cold water at a low flow rate significantly increases the outlet temperature of heated water from the heat pump. In one version, a heat pump capable of producing 140 °F heated water can now produce heated water at temperatures in excess of 200 °F, while operating the heat pump at its usual pressure and power outputs. Alternatively, tradeoffs can be made between increasing efficiency and / or increasing the outlet load temperature of water heated by the pump in a water heating system.

[0015] In accordance with at least one embodiment, the cold water is supplied from at least one storage tank at a load side of the heat pump. The heat pump employs a heat exchanger, the heat exchanger being a counter flow heat exchanger. In at least one embodiment, the flow rate through the heat pump is less than 0.33 gpm per ton heat pump capacity and according to another embodiment being about 0.5 gpm / ton heat capacity or lower.

[0016] In one or more embodiments, the method further comprises monitoring the temperature of the cold water entering the heat pump and deactivating the heat pump if the temperature is above a predetermined temperature. In another version, the volume of stored cold water is measured wherein the heat pump is active only if the measured cold water volume is above a predetermined volume.

[0017] Water heated by the heat pump is supplied to at least one storage tank. In at least one embodiment, a plurality of storage tanks is disposed in series with one another and in which the storage tank closest in the flow path to the heat pump is the cold water storage source. In at least one embodiment, the concepts described herein can be applied to one or more heat pumps disposed in a commercial or residential geothermally-based hot water heating system.

[0018] In accordance with yet another aspect of the teachings provided herein, a geothermally- based system for creating hot water, the system comprising a ground source of water; a heat pump for creating heated water; and at least one storage tank coupled to the heat pump and the ground source, in which the at least one storage tank initially contains cold water from the ground source to be supplied to the heat pump as a cold storage source wherein the cold water from the cold water source is supplied to the heat pump at a low flow rate to achieve high lift while energy consumption by the heat pump is actually reduced.

[0019] In at least one alternative version, the load outlet temperature of the heat pump(s) used in the heating system can be significantly increased, if needed, by operating the heat pump at its usual efficiency (COP) when supplying cold water from the cold water storage at low flow rates. The heat transfer obtained using cold water at low flow rates can be used, depending on the operation for increasing the outlet load temperature of water and / or increasing efficiency of the heat pump(s), as needed.

[0020] In at least one embodiment, the system further comprises one or more controls for continually stabilizing the system based on user demand for heated water. In an embodiment, the one or more controls comprise a controller and at least one sensor configured to monitor the temperature of water entering the heat pump, wherein the monitored temperature is compared to a stored setpoint temperature and in which the heat pump is activated or deactivated based on a predetermined difference between the monitored temperature and the setpoint temperature. In one or more versions, the one or more controls further comprise at least one sensor for monitoring the temperature of water in the cold storage source in which the controller is configured to disable the system when the monitored temperature in the cold storage source is above a predetermined temperature or in which the volume of cold water in the cold storage space is below a predetermined volume.

[0021] According to at least one embodiment, water heated by the heat pump is directed to the one or more storage tanks, wherein the low flow rate of water through the heat pump maintains stratification of heated and cold water within the one or more storage tanks, including the cold storage source. In an embodiment, the one or more storage tanks comprise at least two (2) storage tanks placed in series relative to one another, and in which the storage tank closest to the heat pump is the cold storage source. In at least one embodiment, the heat pump utilizes a counter flow heat exchanger. According to an embodiment, the system comprises two or more heat pumps and in which the controller is configured to activate or deactivate one or more of the heat pumps based on the monitored temperature of water entering a first heat pump, as compared to the setpoint. In an embodiment the system comprises two or more heat pumps in which the controller is configured to activate or deactivate one or more of the two or more heat pumps based on a monitored volume of stored cold water. According to at least one version, a first heat pump of the two or more heat pumps is activated or deactivated based on a first predetermined volume difference between monitored water entering the first heat pump and the setpoint and in which a second heat pump of the two or more heat pumps is activated or deactivated based on a second predetermined temperature or volume difference between the monitored temperature or stored volume of water. In an embodiment, the first heat pump is activated based on the presence of a first predetermined volume of stored cold water and in which a second heat pump is activated or deactivated based on a second predetermined temperature difference between the monitored temperature of water entering the first heat pump and the setpoint.

[0022] In accordance with yet another aspect of the teachings provided herein, there is provided a process for producing hot water in a geothermally-based heating system, the process comprising the steps of coupling a heat pump to one or more storage tanks, at least one of the one or more storage tanks containing cold water from a ground source; flowing cold water from the at least one storage tank through the heat pump at a low flow rate to create high lift in producing heated water with reduced energy consumption; and flowing the heated water to the one or more storage tanks and in which the low flow rate maintains stratification of the heated and cold water in at least one of the one or more storage tanks. Using this process, the efficiency of the heat pump(s) used in the system can be significantly increased and / or the outlet load temperature of heated water can be significantly increased even while operating the heat pump at its rated efficiency (COP).

[0023] In at least one embodiment, the one or more storage tanks comprise at least two storage tanks that are coupled to one another in series relation to one another. The process can further comprise the additional steps of monitoring at least one of the temperature and the volume of the water entering the heat pump and at least one of comparing the temperature of the entering water to a setpoint temperature and the monitored volume to a predetermined volume, wherein the heat pump is activated or deactivated based on a predetermined difference between at least one of the setpoint and monitored water temperature and the predetermined volume and monitored volume.

[0024] In at least one embodiment, the process further comprises activating or deactivating a second heat pump in conjunction with the first heat pump when at least one of the monitored temperature and monitored volume of the entering water are based on at least one of a second predetermined difference between the setpoint and monitored water temperature and the predetermined volume and monitored volume of water.

[0025] In one or more embodiments, the process further comprises monitoring at least one of the temperature and volume of water in at least one of the one or more storage tanks and deactivating the system when at least one of the monitored temperature exceeds a predetermined temperature and the monitored volume exceeds a predetermined volume.

[0026] The process can further comprise adding water from the ground source to the one or more storage tanks to provide a cold water storage source when the monitored temperature of water in the one or more storage tanks exceeds at least one of the predetermined temperature or the volume of cold water is below a predetermined volume.

[0027] Accordingly, and in accordance with at least one embodiment, a system that is defined with a different piping design paired with different and more sophisticated controls has been developed, the system embodying the concepts of high lift (meaning a high temperature difference between entering and leaving hot water) coupled with varying flow and the benefit of storage of cold water to achieve higher efficiencies in a novel manner. Alternatively, the increase in heat energy provided by the low flow, high lift design permits significant and prominent increases in the load outlet temperature of heated water from the heat pump. It has been determined that outlet load water temperature increases on the order of 60 °F (140 - 200 °F) or more can be realized by adding cold water at low flow rates while operating the heat pump at its normal / typical pressures and power outputs. Alternatively, both efficiency and outlet load temperature increases can be realized given the amount of heat transfer provided by the influx of cold water at low flow rates. These inventive concepts were unexpected and counterintuitive, yet designs embodying the herein described concepts have resulted in over twice the specified efficiencies, as compared to the original scope.

[0028] An important aspect of the present invention is a heating system that uses cold water from storage entering the counterflow heat exchanger of the heat pump as long as possible via low flow rates, in order to transfer much more heat energy effectively and efficiently into the heated water and with reduced energy consumption by the heat pump. In order to accomplish this counterintuitive objective, cold water initially enters a first storage tank until the first tank is filled with cold water. The colder the temperature of the stored water, the more efficient is the resulting heat transfer. In addition, and for overall operation, the larger the supply of stored cold water, the longer the heat pump(s) can be efficiently operated under the foregoing favorable conditions. As a result, the most effective combination is having an adequate volumetric storage of sufficiently cold water in the system, while the heat pump is being operated at low flow rates through the pump(s).

[0029] These and other features and advantages will be readily apparent from the following Detailed Description, which should be read in conjunction with the accompanying drawings.

[0030] Brief Description of the Drawings

[0031] FIGS. 1(a) and 1(b) depict water heating system piping designs made in accordance with the known art;

[0032] FIG. 1(c) schematically depicts another water heating system in accordance with the known art

[0033] FIG. 2 depicts a known heat pump and the effect of same on efficiency (COP) when configured for either low or high lift;

[0034] FIG. 3 is a specification sheet for another known heat pump; FIG. 4(a) graphically depicts Coefficient of Performance (COP) versus leaving load temperature between the heat pumps of FIGS. 2 and 3;

[0035] FIG. 4(b) graphically illustrates improved efficiencies between the various heat pumps of FIGS. 2 and 3;

[0036] FIG. 5 depicts a system output for the heat pump of FIG. 3, when the heat pump is configured for high flow;

[0037] FIG. 6(a) depicts a system output for the heat pump of FIG. 3, when cold water and low flow rates are used on the load side of the heat pump and providing an increase in efficiency of the heat pump;

[0038] FIG. 6(b) depicts a system output for the heat pump of FIG. 3, when cold water and flow rates are used on the load side of the heat pump, while the heat pump operates at its usual efficiency (COP) and depicting a massive increase in load outlet temperature;

[0039] FIG. 7 graphically depicts the increase in efficiency demonstrated by the system output of FIG. 6 using low flow;

[0040] FIG. 8(a) schematically depicts a heating system in accordance with aspects of the present invention including a series arrangement of storage tanks to promote stratification in combination with low flow rates;

[0041] FIG. 8(b) schematically depicts the heating system of FIG. 8(a), showing the maintained stratification of the cold water and hot water in the cold storage tank;

[0042] FIG. 9 graphically depicts further increases in efficiency in the heat pump as realized by low flow, high lift, and series relation between the storage tanks; FIG. 10 is a flow chart depicting control logic for a heating system made in accordance with the present invention; and

[0043] FIGS. 11(a) - 11(c) schematically depict a building heating system in accordance with aspects of the present invention and at varying stages of hot water demand.

[0044] Detailed Description

[0045] The following relates to various embodiments of a geothermally-based water heating system made in accordance with aspects of the present invention. The herein described embodiments are specific to a residential building heating system, though it will be readily apparent that the herein described heating system can be employed in many settings including schools, hospitals, and office buildings and in fact any structure(s) having a plurality of tenants or customers. More specifically, an evolution of an exemplary hot water heating system in accordance with aspects of the present invention is now described. It will be readily apparent that there are a number of modifications and variations that can be made embodying the inventive concepts discussed herein. In addition, the accompanying drawings are intended to depict salient features of the invention. The drawings should not be relied upon for scaling purposes.

[0046] According to an initial iteration (and the basis for the energy / emission saving calculations) a system was employed that initially included a first heat pump, the latter being a model GW-15 manufactured by Colmac, Inc., the heat pump having the capability of creating 140 °F hot water, with an overall efficiency of 180 %, equaling a Coefficient of Performance (COP) of 1.8 and whose specifications are listed in FIG. 2.

[0047] For purposes of the present invention, it was felt that the Colmac heat pump shown in FIG. 2 to be subpar in its current design, and furthermore the heat pump utilized a refrigerant (R134a), which was soon to be phased out due to its climate impact. As a result, and for purposes of evaluating the design concepts, an alternative and existing heat pump Model NXW360, from Waterfurnace International Inc., FIG. 3(a), was configured with a compressor capable of making 140 °F water, and further including a double wall vented counter-flow heat exchanger certified for potable water. This specific heat pump delivered an increased COP of 2.2 (220% efficiency), a significant increase of 22% in efficiency when compared to the original heat pump considered (COP 1 .8), meaning the geothermal system could see an efficiency improvement of 22% compared with the originally configured heat pump. FIG. 3 provides a specification of the latter heat pump.

[0048] FIGS. 4(a) and 4(b) depict graphical comparisons of the noted efficiency / improvement gained using the Waterfurnace heat pump, versus the originally selected Colmac heat pump. The Waterfurnace heat pump operated experimentally with a maximum temperature of 148 degrees F, a power consumption of 41.6 kilowatts, and discharge pressures of 600 psi, all at traditionally higher water flow rates (60 - 90 gpm), each as further shown as compared favorably to the system output depicted in FIG. 5, with a lead inlet water temperature of 136.8 F and a lead output water temperature of 148.2 F.

[0049] It is noted, however, that a low flow was still desired to prevent mixing of hot and cold water in the storage tanks to maintain the stratification of hot and cold water therein. When redirecting the cold water into the heat pump, instead of the storage tanks, and reducing the flow through the heat pump to 10 gpm or less, a significantly higher lift resulted, which heated the water from 39 °F to 141.8 °F, but at the same time reduced the pressures from about 600 PSI to about 400 PSI per compressor, and also reduced the power consumption from 41.6 KW to 29.6 KW for both compressors, as shown in the system output of FIG. 6(a). Each of these observations and results, as shown in FIG. 6(a), were completely counterintuitive to any conventional knowledge and wisdom concerning the function of heat pumps and alone served as a significant and inventive leap not heretofore realized. Even more surprising was a significant jump in efficiency of the Waterfumace heat pump from 2.2 by utilizing entering cold water under low flow rates and high lift( to a now measured 3.42 COP (see labeled Waterfurnace low flow), as shown graphically in FIG. 7. From this inventive insight, it became abundantly clear that a low flow was not only possible, but actually desirable, and could significantly boost overall system efficiency.

[0050] Alternatively, this large amount of heat energy generated using cold water and low flow rates through the heat pump can be used to produce a massive increase in the load outlet temperature of heated water. As shown in the system output of FIG. 6(b), and operating the heat pump of FIG. 3 at the same pressure and power output regimes as that shown in FIG. 5 (COP = 2.2), but using cold load inlet water (about 48 °F) at low flow rates (in the range about 10 gpm or less), the outlet load temperature reached in excess of 200 °F or about a 60 °F increase, which again is completely counterintuitive to known heating methodologies.

[0051] A critical key for purposes of the present invention is to operate a heating system using the cold water entering the counterflow heat exchanger of the heat pump as long as possible via the low flow rates, in order to transfer much more heat energy effectively and efficiently into the heated water. In order to accomplish this goal, the cold water initially enters the first storage tank until the first tank is filled with cold water creating a cold storage reservoir. The colder the water temperature, the more efficient is the resulting heat transfer. In addition, and for overall operation, the larger the supply of stored cold water, the longer the heat pump can be efficiently operated under the foregoing favorable conditions. As a result, the most effective combination is to provide an adequate volumetric storage of sufficiently cold water in the system, as operated at low flow rates. To that end, if higher flow rates were used, then the only way to get additional water for higher flow would be from the storage tanks, which are already heated and resulting in hotter water to get into the heat pump. Conversely, warmer water entering the heat pump, as in traditional high flow rate heating systems, results in lower efficiencies and less amounts of lift of heated water leaving the heat pump.

[0052] However, the amount of cold make up water flow into the heat pump is now determined by the hot water leaving the storage tanks into the building / structure for a system, which can fluctuate significantly dependent on the hot water usage of the building and the tenants. Consequently, this fluctuation required a radical new storage tank piping design, with the storage tanks 820, 824, 828 being piped in series, not in parallel, in conjunction with low flow, as shown in FIG. 8(a) and 8(b) and using the same heat pump 800 having circulation pump 814 on the lead input and valving 818 at the lead output to the heat pump 800. It should be noted that the source connection between the heat pump and the ground source via a loop field is not shown in these views for the sake of clarity. Using this latter series arrangement, hot and cold water stratification was effectively maintained in the upper and lower portions of the storage tank 820 closest to the heat pump 800 along the flow path with the cold water in the lower portion 825 of the storage tank 820 and heated water in the upper portion 827 thereof and with at least the storage tank 820 being initially filled with sufficiently cold water. In this system, heated water is returned from the heat pump 800 to the storage tanks 824, 822 and 820 for hot water storage with the above-noted stratification

[0053] With reference to FIG. 8(b) and now with low flow and the preservation of the stratification in place (no more hot and cold water mixing) the first storage tank 820 is now solely used for cold water storage in order to significantly increase the amount of time to operate the heat pump(s) under those favorable, as well as extremely efficient low flow conditions. The foregoing further exemplifies how counterintuitive this novel approach is; that is to provide cold water storage to significantly increase the efficiency of hot water production. The efficiencies achieved are comparatively shown in FIG. 9.

[0054] Another component of the system, as previously discussed, is the cold storage and the control system to maximize the amount of cold storage to supply the heat pump(s) with cold water for a maximum time to increase their efficiency. An important aspect is to do so at low velocity (low flow rates) so that the tank stratification is not disturbed, and undesired mixing of hot and cold water is minimized.

[0055] In addition, a new control design and new sequence of operations were needed. Since the water temperature(s) entering the heat pump(s) would fluctuate significantly every fraction of a second, depending on how much water was being used or how many faucets, showers and washing machines were using hot water at any given time, a new control system had to be designed to ensure that the water flow adopts to given temperatures instantaneously. Otherwise, and without any proper control sequencing, the system would be inherently unstable and result in frequent high-pressure lockouts of the heat pumps.

[0056] A custom, design build control system, ensuring stable operating conditions was created in accordance with at least one embodiment. That way the stratification of the storage tanks is preserved and a large amount 140 °F is actually stored in the tanks, ensuring to cover peak hot water loads. With reference to FIG. 10, there is shown a flowchart that functionally describes an examplary control sequencing. This flowchart is related to the functioning of a specific heating system, such as that schematically shown in FIG. 11(a), which is first now briefly described. The heating system of FIG. 1 1(a) utilizes a pair of heat pumps 1 110, 1120, each having a counterflow heat exchanger that enables connectivity to a ground source via a loop field as part of a geothermal heating system. The heat pumps 1110, 1120 used in this specific system are the Waterfurnace heat pumps previously described, but it will be understood that the selection and number of heat pumps can be suitably varied provided that the heat pumps are capable of creating heated water. Each heat pump 1110, 1120 includes a counter-flow heat exchanger, which enables connectivity to a ground source. Water from the ground source and a refrigerant are circulated through the source inlet and source outlet of each of the heat pumps 1110, 1120, with the entering source being intermediately coupled to an air separation and expansion tank or column 1124 that is configured to dissolve air bubbles from the entering liquid, as well as a set of redundant pump stacks 1127.

[0057] One or more variable speed (e.g., circulation) pumps 1130 are disposed at the load inlet of each heat pump 1110, 1120 to control the water temperature produced by the heat pumps 1110, 1120, as well as a fast reacting valve 1140 disposed at the load outlet of each pump to further supplement the regulation of the water flow. In this system, heat pump HP1 or 1110 is referred to as the “lead heat pump”, and heat pump HP2 or 1120 is referred to as the “lag heat pump”. It will be understood that the roles of the heat pumps 1110, 1120 can be reversed after a predetermined number of cycles to avoid overuse. The heat pumps 1110, 1120 are fluidically coupled via piping to a series of storage tanks STI 1160, ST2 1170 and ST3 1180, each of which are disposed in series arrangement with one another. The closest storage tank STI 1160 to the heat pumps 1110, 1120 along the flow path is herein referred to as the “cold storage tank” or “cold storage source”. The herein described system includes a plurality of fast reacting and reporting temperature sensors (not shown) that are configured for measuring the incoming and outgoing water temperature to and from the heat pump(s), as well as temperature sensors being provided in or about the storage tanks 1160, 1170 and 1180. It will be understood that three (3) storage tanks STI, ST2 and ST3 are provided in this system embodiment, though this parameter can also be suitably varied. For example, and according to an alternative embodiment, a single large storage tank could be utilized. According to at least one embodiment, temperature sensors are disposed at the inlet of the heat pump(s) 1110, 1120, at a middle location within the first storage tank STI 1160 acting as the cold storage reservoir in this example, and at the bottom of the tank 1160. In at least some versions, the temperature sensors might be placed at a certain distance from the heat pump to further predict the entering or leaving water temperature in and out of the heat pump. Placement of the temperature sensors further enables a determination of volume of cold water in the cold storage tank STI 1160. Certain control algorithms can be applied vis a vis a processor to control the water flow via the variable speed circulation pump 1130 and the variable speed valve 1140. An electric buffer device 1190 is coupled to the system adjacent the furthest storage tank 1180 from the heat pumps 1110, 1120 along the flow path. A master controller (not shown) controls the logic herein described in terms of operation, the controller having a keypad or other user interface, as well as memory and the processor that stores the specific control algorithms and in which inputted readings from the temperature sensors can be received and in which the pumps, compressors and valving of the system can be controlled.

[0058] With reference to FIG. 10, the system is started at step 1004 and then initialized at step 1008. A determination is then made as to the temperature of hot storage water in the system by monitoring the various temperature sensors and monitoring the temperature of the water to determine if the temperature is less than a predetermined setpoint temperature or within a percentage range of the setpoint, as stored by the master controller. If the monitored hot storage temperature is equal to or greater than the stored setpoint, then per steps 1010, 1012, 1014 and 1016, the compressor of the lead heat pump (step 1010), the source pump (step 1012), the lead load pump (step 1014), and the lead load valve (step 1016) are each switched OFF. If, on the other hand, the monitored hot storage water temperature is less than the setpoint, then a further determination is made at step 1020 to determine whether the temperature of cold storage water in the system is less than a predetermined low threshold. If the cold storage is not less than the low threshold, then the control logic determines if the hot storage in terms of both temperature and volume is greater than or equal to the setpoint (step 1062), similar to step 1008 and reverts to switching off each of the compressor of the lead heat pump (step 1010), source pump (step 1012), lead load pump (step 1014) and closing of the lead load valve (step 1016). By placement of the temperature sensors within the cold storage tank STI, both temperature and volume of cold water storage can be monitored by the system.

[0059] If the temperature hot storage is below the set point and the temperature of the cold storage water is less than the low threshold indicative of the presence of sufficiently cold water in the cold storage tank, then each of the compressor of the lead heat pump (step 1024), the source pump (step 1026), the lead load pump (step 1028) are switched ON and the lead load valve is opened (step 1030). Upon switching ON of the source pump and per step 1032, the source pump is modulated in order to maintain suction temperature into the heat pump at the setpoint. Similarly, and upon opening the lead load pump, the pump is modulated to maintain the load water temperature at the setpoint temperature (step 1034) and the opening of the lead load valve creates modulation of the valve to maintain the load water temperature at the setpoint temperature (step 1036).

[0060] At the same time, a parallel determination is made (step 1038) as to whether the hot storage temperature is increasing. If the hot storage temperature is not increasing, then a further determination is made via the temperature sensor(s) as to whether the hot storage temperature is actually decreasing. If the hot storage temperature is decreasing, then the compressor of the lag pump, as well as the lag load pump are each switched ON (steps 1042, 1044) and the lag load valve is opened (step 1046). Upon switching ON of the lag load pump and per step 1048, the load pump of the lag heat pump is modulated in order to maintain load water temperature into the heat pump at the setpoint. Similarly, and upon opening the opening of the lead load valve, modulation of the fast reacting valve occurs (step 1050) to maintain the load water temperature at the setpoint temperature.

[0061] A parallel determination is made according to this control logic after the compressor of the lag pump has been switch on (step 1056) to determine if the temperature and volume of the hot storage is increasing. If the hot storage is increasing, then a follow-up determination is made as to whether the hot storage temperature increase is greater than or equal to a predetermined lag threshold (step 1058). If this latter threshold has been met, then the compressor of the lag heat pump is switched OFF (step 1060), the lag load pump is switched OFF (step 1052) and lag load valve is closed (step 1054). If the hot storage is not increasing (step 1056) and / or if the lag threshold has not been met (step 1058), then the lag pump remains fully active in modulating the load water temperature to the setpoint. Similarly, the lead heat pump remains active until the hot storage has reached or exceeded the setpoint temperature (step 1062). Significant to the system’s operation and if the cold water storage is depleted; that is, the monitored water temperatures entering the heat pump are increasing, which are recognized by the temperature sensors in the entering water lines, the heat pump(s) will be shut down and the valving will be opened between the bottom of the first storage tank and the cold supply to permit cold water to fill the first storage tank and with any retained heated water to be pushed to the remaining storage tanks. This will again create the reservoir for cold storage.

[0062] FIGS. 11(b) and 11(c) depict sequential time frames of the examplary system including the above noted control logic and indicating the advantageous features of the invention. This system as shown is the system previously described at FIG. 11(a) but at a different point of time. FIG. 11(b) illustrates a situation in which the lead heat pump (HP2) is running in which the entering temperature of water is 119.2 °F and the water leaving temperature is 140.5 °F. Power usage of this heat pump is measured at 18. 4 KW per compressor. Water is flowing backwards through the storage tanks STI - ST3, with water entering the first storage tank STI at 135.7 °F and pushing water out from the top through the bottom of the tank ST-1, leaving the bottom of the tank ST-1 at 130.4 °F. At this point in the system, there is very little cold storage and both heat pumps HP-1 and HP-2 are shut down, as shown. Water flow into storage tank ST-1 has reversed due to the lack of cold storage in the system, with water entering from the cold supply from the bottom of the storage tank ST-1 at 68.2 °F and pushing hot water out through the top towards tank ST-2 in the series connection at 135.1 °F.

[0063] The cold storage and hot storages are now enabled to allow HP -2 to be activated with the system as shown with maximum amount of cold storage in terms of temperature and volume, shown in FIG. 11(c), with water entering the load side of the heat pump HP -2 at 67.8 F and leaving at 137.2 F, which is a high lift of 69.4 F. Conversely and unexpectedly, the power consumption is down from 18.4 to 15.3 KW per compressor, which is a counterintuitive result given the considerably higher lift.

[0064] Appendix A includes another examplery and somewhat more detailed control logic for a high lift low flow rate heating system. It has been further determined in at least one embodiment that the final efficiency (COP) of the heat pump(s) can be further increased by higher loop field temperatures thus far (per the following Table.

[0065] More specifically, this table shows multiple measurements over time documenting the stable operation of the system, but also the extremely high efficiency (COP over 4.5) despite high LLT (leaving load temperatures) above 140 °F, which normally would result in COP around or less than 2.2 (Waterfurnace unit). In addition, and as previously shown in FIG. 6(b) and using the same efficiencies (COP=2.2), the load outlet temperature of heated water can be increased significantly given the increase in heat energy that is available. Usually, the heat extraction from the source water is rated at around 170,200 BTU / H (FIG. 3), however, due to the entering cold load water (ELT) around 70 °F (low flow) instead of 130+°F (high flow) in FIG. 3, the system can transfer significantly higher energy from the source water, in this case Heat Extraction (HE) is between 380,000+ BTU / H and 400,000+ BTU / H as shown in the table above. In addition, the energy consumption of compressor A in KW (KWA) and compressor B in KW (KWB) is significantly lower than rated in high flow scenarios (i.e., usually around 20+KW). Thus, heat extraction from the ground source is significantly higher (more than 2X) and electrical consumption is significantly lower (by about 20%), resulting in significantly higher efficiencies overall).

[0066] It is also conceivable that performance (COP) of the system might be slightly decreased by colder ground temperatures and higher loads, especially in the winter in colder climes, after long term load on the loop field. However, it was further observed that operating the heat pump(s) at lower water temperatures, for example at 130 °F instead of 140 °F, would significantly increase efficiencies (i.e., COP) or alternatively load outlet temperatures, further.

[0067] Upon the counterintuitive and unexpected realization / understanding that heat pumps work more efficient when flushed continuously with cold water, an overriding goal became to actually provide cold storage, in lieu of solely hot storage water, to allow the heat pumps to operate as long as possible under those favorable conditions in which significantly greater efficiencies and / or outlet load temperatures of heated water can be realized.

[0068] An additional realized benefit of the low flow was significantly reduced pumping power. Low and variable flow now requires the installation and control of very efficient variable speed ECM pumps, which under low flow scenarios use only around 50 watts, instead of 1,000 watts.

[0069] As a result of the foregoing design, a novel anomaly was observed showing that geothermal heat pumps can generate domestic hot water with thus far unprecedented efficiencies. Due to high population densities in the apartments representing over 35%-40% of the overall energy load, and 40% - 45% of the total fossil fuel use, the above described efficiency gains might have significant and demonstrable impact in benefitting the energy and emission reductions goals and electrification efforts.

[0070] While the concepts have been described in terms of particular variations and illustrative figures, those of ordinary skill in the art will recognize the concepts are not limited to the variations or figures described. In addition, where methods and steps described above indicate certain events occurring in certain order, those of ordinary skill in the art will recognize that the ordering of certain steps may be modified and that such modifications are in accordance with one or more variations. Additionally, certain of the steps may be performed concurrently in a parallel process, when possible, as well as performed sequentially as described above. Therefore, to the extent there are variations involving the concepts described herein, which are within the spirit of the disclosure or equivalent to that recited found in the claims, it is the intent that this patent will cover those variations as well. To the extent that the claims recite the phrase “at least one of’ in reference to a plurality of elements, this is intended to mean at least one or more of the listed elements and is not limited to at least one of each element. For example, “at least one of an element A, element B, and element C,” is intended to indicate element A alone, or element B alone, or element C alone, or any combination thereof. “At least one of element A, element B, and element C” is not intended to be limited to at least one of an element A, at least one of an element B, and at least one of an element C.

[0071] This Detailed Description uses examples to disclose various aspects of the pet training system, including the best mode, and to enable any person skilled in the art to practice, including making and using any devices or systems and performing any incorporated methods. The intended scope of the concepts described herein is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. For example, it will be clearly understood that the shapes and configurations of the receiver and remote transmitting / control device can be suitably varied while still performing all functions that have been described herein.

[0072] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”), and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes,” or “contains” one or more steps or elements possesses those one or more steps or elements but is not limited to possessing only those one or more steps or elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes,” or “contains” one or more features possesses those one or more features but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way but may also be configured in ways that are not listed.

[0073] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below, if any, are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description set forth herein has been presented for purposes of illustration and description but is not intended to be exhaustive or limited to the form disclosed. Other modifications and / or variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiments were chosen and described in order to best explain the principles of one or more aspects set forth herein and the practical application, and to enable others of ordinary skill in the art to understand one or more aspects as described herein for various embodiments with various modifications as are suited to the particular use contemplated and in accordance with the following appended claims. Additional embodiments include any one of the embodiments described above and described in any and all exhibits and other materials submitted herewith, where one or more of its components, functionalities or structures are interchanged with, replaced by, or augmented by one or more of the components, functionalities or structures of a different embodiment described above.

[0074] APPENDIX A - EXEMPLARY CONTROL SEQUENCING FOR HIGH-LIFT, LOW FLOW HEATING SYSTEM

[0075] Master Controller functions, variables, and BMS Set Points

[0076] The following list of variables and set points will include, but not be limited to the following:

[0077] 1. System On / OFF (BMS Network Binary Value)

[0078] 2. Hot Water Supply Set Point (140 °F adj) (BMS Network Analog Value)

[0079] 3. Saturated Suction Temperature Source Pump Set Point (35 °F adj) (BMS Network Analog Value)

[0080] 4. ON Offset (40 °F adj) (Master Controller interface only)

[0081] 5. Lag OFF Offset (15 °F adj) (Master Controller interface only)

[0082] 6. Lead OFF Offset (15 °F adj) (Master Controller interface only)

[0083] 7. Fluid Temperature Max (135 °F adj) (Master Controller interface only)Grundfos Load Start Percent (40% adj) (Master Controller interface only)Wilo Source Start Percent (25% adj) (Master Controller interface only)

[0084] 8. Heatpump ON Timer (30 s adj) (Master Controller interface only)

[0085] 9. Heatpump OFF Timer (10 s adj) (Master Controller interface only)

[0086] 10. Saturated Suction Temperature Source Pump Set Point (35 °F adj) (BMS Network Analog Value)

[0087] 11. Leaving Load Temperature Setpoint (135 °F adj) (Master Controller interface only)

[0088] 12. Grundfos minimum Speed Temperature (85 °F adj) (Master Controller interface only)

[0089] 13. Load Valve Full Open Temperature (80 °F adj) (Master Controller interface only)

[0090] 14. Network alarm reset - Central work station can clear alarms at each building (Binary Value)

[0091] 15. Network / local mode - The Master Controller can be set at a keypad or alternatively at a central work station in the system Network or a Local mode for service. The mode can be commanded at either location and both have equal priority. (Binary Value) The list of control functions will include, but will not be limited to the following functions:

[0092] 1. Setpoint and Timer Control for staging of the Heatpumps

[0093] 2. PID Loop for Source Pumps to maintain suction temperature set point in all circuits (Master Controller Keypad only)

[0094] 3. PID Loop for Load Pumps to maintain Leaving Load Temperature of Heatpump 1&2 (Master Controller Keypad only)

[0095] 4. PID Loop for Load Valves 1 to maintain Leaving Load Temperature of Heatpump 1&2 (Master Controller Keypad only)

[0096] Heatpump Staging:

[0097] The Master Controller shall utilize an Equal Run Time Rotation to determine the lead and the lag Heatpump on a monthly basis and all ON and OFF commands shall be done over bacnet via “network” Y1 / Y2 calls to each Heat Pump.

[0098] The Master Controller shall use the Tank Sensor (TS-1) mounted in the closest Tank to the Heatpump as input to determine the compressor staging required to meet the hot water SETPOINT (140 °F adjustable through BMS and via Master Controller Interface, adjustable range shall be 120-145 °F).

[0099] When the value of TS-1 drops below SETPOINT less 40 °F (“ON Offset” from SETPOINT shall be adjustable through Master Controller interface only) the lead Heatpump (both compressors - Y1&Y2 signal) shall be commanded ON.

[0100] If TS-1 is still below SETPOINT less 40 °F (“ON Offset” from SETPOINT shall be adjustable through Master Controller interface only) after a period of 15 minutes (adjustable through Master Controller interface only), the lag Heatpump (both compressors - Y1&Y2 signal) shall be commanded ON. In addition to a time delay, the staging of the heatpump could also by facilitated by a second temperature sensor located either in a tank or connection pipe further away from the heatpump.

[0101] When TS-1 reaches SETPOINT less 15 °F (“Lag OFF Offset” from SETPOINT shall be adjustable through Master Controller interface only) the lag Heatpump (both compressors - Y1&Y2 signal) shall be commanded OFF, as long as the minimum run time of 5 minutes for the lag Heatpump has elapsed, otherwise the OFF command shall be sent immediately upon the elapsing of the minimum run time.

[0102] When TS-1 reaches SETPOINT less 5 °F (“Lead OFF Offset” from SETPOINT shall be adjustable through Master Controller interface only) the lead Heatpump (both compressors - Y1&Y2 signal) shall be commanded OFF.

[0103] In addition, the Master Controller shall use the load heat exchanger entering water temperature sensors installed inside the Heatpump (analog value available via Bacnet, Inst Number: 19 - LoadEntWaterTemp-st [°F]) as input for a high limit shut off for each of the Heatpumps. Each Heatpump shall be commanded OFF if the entering water temperature of the corresponding Heatpump is at 135 °F or above (adjustable through Master Controller interface only, adjustable Range shall be 105 °F - 140 °F).

[0104] Lead Heatpump ON Command procedure:

[0105] {Initialization Sequence} When a heating demand for the Lead Heatpump, based on the TS-1 value, is present the corresponding Load Valve shall be fully opened via a 10 VDC signal and the corresponding Grundfos Load Pump shall be set to 16% (adjustable through Master Controller interface only). In addition and at the same time, the source isolation valve shall be opened and the Lead Source Pump Stack shall be set 25% (adjustable through Master Controller interface only).

[0106] Once flow is proven by the flow switch or pump GPM, for both the source and load side, both compressors of the Lead Heatpump shall be commanded ON via a network Y1 & Y2 command. Once the compressor has been proven to be in operation (bacnet value from heatpump internal compressor current sensors) and a period of 30 seconds (adjustable through Master Controller interface only) has elapsed the Load Pump and Load Valve Control shall be switched over to the PID-control Loop to maintain the leaving temperature setpoint and the Source pump shall be switched over to the PID-control Loop to maintain the Saturated Suction Temperature Set Point.

[0107] Lag Heatpump ON Command procedure: When a heating demand for the Lag heatpump, based on the TS-1 value and timer, is present the Load Valve and Grundfos Load Pump for both the Lead and the Lag Heatpump shall be initialized simultaneously to prevent a stalling of the lead heatpump water flow.

[0108] Both Load Valves shall be fully opened via a 10 VDC signal and both Grundfos Load Pumps shall be set to 20 % (preferably adjustable through the Master Controller interface only).

[0109] Once flow is proven by the flow switch or pump GPM, for both the source and load side, both compressors of the Lag Heatpump shall be commanded ON via a network Y1 & Y2 command. Once the compressor has been proven to be in operation (bacnet value from heatpump internal compressor current sensors) and a period of 30s (adjustable through Master Controller interface only) has elapsed the Load Pumps and Load Valves Control shall be switched over to the PID-control Loop to maintain the leaving temperature setpoint.

[0110] Lead Heatpump OFF Command procedure:

[0111] When a heating demand for the Lead Heatpump, based on the TS-1 value, is satisfied and no longer present, both compressors of the Lead Heatpump shall be commanded OFF. Once the compressor has been proven to be not in operation (bacnet value from heatpump internal compressor current sensors) and a period of 10 seconds (adjustable through Master Controller interface only) has elapsed, the corresponding Load Valve shall be closed with a 0 VDC signal, the corresponding Load Pump shall be commanded OFF and the Lead Source Pump Stack shall be commanded OFF.

[0112] Lag Heatpump OFF Command procedure:

[0113] When a heating demand for the Lag Heatpump, based on the TS-1 value, is satisfied and no longer present, both compressors of the Lag Heatpump shall be commanded OFF. Once the compressor has been proven to be not in operation (bacnet value from heatpump internal compressor current sensors) and a period of 10 seconds (adjustable through Master Controller interface only) has elapsed, the corresponding Load Valve shall be closed with a 0VDC signal and the corresponding Load Pump shall be commanded OFF. Source Pump Control (Ground Loop):

[0114] The Master Controller shall directly control the Wilo Source Pumps over bacnet to maintain the Saturated Suction Temperature Source Pump Set Point (35 °F adjustable through BMS and via Master Controller Interface, adjustable range shall be 30-45 °F). The Saturated suction temperature is a standard analog value available via bacnet from the Heatpump controller.

[0115] There is a 4 total of source pumps herein referred to as S1 / S2 / S3 / S4 - with S1 / S2 being in series, S3 / S4 being in series, and S1 / S2 Stack being in parallel with the S3 / S4 Stack. The Master Controller shall utilize an Equal Run Time Rotation to determine the lead and the lag Source Pump Stack on a monthly basis.

[0116] After the Lead Heatpump has been commanded ON and the initial start procedure timer has elapsed, the commanded source pump speed shall be increased or decreased using a PID- control Loop to maintain the saturated suction temperature setpoint.

[0117] When the Lag Heatpump has been commanded ON in addition to the Lead Heatpump, the Master Controller will increase or decrease the speed of the pumps to ensure that all circuits are maintaining the saturated suction temperature set point (at a minimum).

[0118] When no compressor commands are present the Lead Source Pump Stack will be commanded OFF.

[0119] Each pump will have data sent back to the master controller and BMS. This data will include pump RPM, estimated flow, estimated Kw consumption, and alarm faults. If an alarm fault is present, the Standby Pump Stack will be enabled to meet the set point and the lead pump.

[0120] Load Pump Control (Domestic Hot Water):

[0121] The Master Controller shall control the Grundfos Load Pumps over bacnet. After the corresponding Heatpump has been commanded ON and the initialization procedure timer has elapsed, the Master Controller shall use the Heatpump Leaving Load Sensor (TS-2 & 3) mounted in the Load Out Pipe from the Lead and Lag Heatpump and wired to the Master Controller as input to maintain the Leaving Load Temperature Setpoint of 135 °F (adjustable through Master Controller interface only, adjustable Range shall be 120F - 145 °F), and use the load heat.

[0122] Instead of a water temperature sensor, it would also be feasible to regulate the Load Pump based on the refrigerant pressure of the corresponding heat pump exchanger entering water temperature sensors installed inside the Heatpump (analog value available via Bacnet, Inst Number: 19 - LoadEntWaterTemp-st [°F]) installed inside the Heatpumps to select the operation mode of each of the Grundfos Pumps.

[0123] There are two (2) control scenarios:

[0124] - Only the Lead Heatpump is On. In this case, the operation mode and modulation shall be based on the Lead Heatpump sensors and the Lag Heatpump Load Grundfos pump shall be OFF

[0125] Both the Lead and the Lag Heatpump are On. In this latter case, the mode of operation shall be determined by the lower of the load heat exchanger entering water temperature sensor values. In addition, the modulation shall be based on the larger of the Heatpump Leaving Load Sensor values.

[0126] It should be noted that instead of using one load pump per heatpump, that alternatively one common load pump could be used that serves all heatpumps in combination through use of a modulating valve per heat pump. In this latter case, the mode of operation shall be determined by the temperatures of all active heatpumps as described.

[0127] The three (3) operation modes the Load Pumps shall have are as follows:

[0128] - OFF

[0129] When both Compressors of the respective Heatpump are commanded OFF, the Grundfos Load Pump shall be shut down.

[0130] - Minimum Speed

[0131] When the Fluid Temperature entering the load heat exchanger is below 85 °F (adjustable through Master Controller interface only) the pump speed shall be set to the minimum. Modulating Speed

[0132] When the Fluid Temperature entering the entering the load heat exchanger is at 85 °F or Above (adjustable through Master Controller interface only) the pump speed shall be controlled by a PID loop to maintain Leaving Load Temperature setpoint. The PID Loop shall use the analog Heatpump Leaving Load Sensor (TS-2 & 3) Leaving Load Temperature sensor mounted in the Load Out Pipe from the Lead and Lag Heatpump and wired to the Master Controller as the feedback data and increase and decrease the pump speed. As previously discussed, it would also be feasible to control the load pump based on the refrigerant.

[0133] Load Valve 0-10V Modulating-Control:

[0134] The Master Controller shall control the Load Valve via a 0-10 volt signal through the Master Controller Point Expander. After the corresponding Heatpump has been commanded ON and the initialization procedure timer has elapsed, the Master Controller shall use the Heatpump Leaving Load Sensor (TS-2 & 3) mounted in the Load Out Pipe from the Lead and Lag Heatpump and wired to the Master Controller as input to maintain the Leaving Load Temperature Setpoint of 135 °F (adjustable through Master Controller interface only, adjustable Range shall be 120 °F - 145 °F), and use the load heat exchanger entering water temperature sensors installed inside the Heatpump (analog value available via Bacnet, Inst Number: 19 - LoadEntWaterTemp- st [°F]) installed inside the Heatpumps to select the operation mode of each of the load valves. The control for the valve shall a low limit of 3.2 volts (the latter being preferably adjustable through the Master Controller interface only), which shall be active during the modulating stage in order to prevent the full closure of the modulating valve. As noted above, it would also be feasible to control the load pump based on the refrigerant pressure. In addition, it should further be noted that this modulating control could also be achieved alternatively using a modulating valve using a different form of communication other than the 0 - 10 volt signal.

[0135] There are two (2) control scenarios: Only the Lead Heatpump is On. In this case, the operation mode and modulation shall be based on the Lead Heatpump sensors and the Lag Heatpump Load Valve shall be fully closed

[0136] Both the Lead and the Lag Heatpump are On. In this latter case, the mode of operation shall be determined by the lower of the load heat exchanger entering water temperature sensor values. And the Modulation shall be based on the larger of the Heatpump Leaving Load Sensor values.

[0137] The three (3) Operation modes that the Load Pumps shall have are as follows:

[0138] - OFF

[0139] When both Compressors of the respective Heatpump are commanded OFF, the Load

[0140] Valve shall be fully closed.

[0141] - Fully Open Stage

[0142] When the Fluid Temperature entering the load heat exchanger is at or above 80 °F (adjustable through Master Controller interface only) Load Valve shall be set to fully open.

[0143] Modulating Stage

[0144] When the Fluid Temperature entering the entering the load heat exchanger is below 80 °F (adjustable through Master Controller interface only) the opening of the Load Valve shall be controlled by a PID loop to maintain Leaving Water Temperature Setpoint. The PID Loop shall use the analog Heatpump Leaving Load Sensor (TS-2 & 3) Leaving Load Temperature sensor mounted in the Load Out Pipe from the Lead and Lag Heatpump and wired to the Master Controller as the feedback data and increase and decrease the Valve Opening Position. As previously noted, it would also be feasible to alternatively control the lead pump based on the refrigerant.

[0145] Error Handling

[0146] Stall of Load Flow / No Load Flow: Should the Grundfos Estimated Flow (analog value available via Bacnet, ID: Al, 5 - readout is in m7hr) return 0 at any time all active controlled load valves shall be commanded open to 80% (adjustable through Master Controller interface only).

[0147] Heatpump Unit Lockout:

[0148] Should the Lead Heatpump Lockout, an automatic changeover from the Lag and Lead Heatpump shall be initialized and the lockout conditions recorded and sent. Then the faulted Heatpump shall be reset via the Bacnet AlarmReset c command.

[0149] Should the Lag Heatpump Lockout, the lockout conditions shall be recorded and sent. Then the faulted Heatpump shall be reset via the Bacnet AlarmReset c command.

[0150] Unexpected Compressor Shut Down:

[0151] Should one of the compressors unexpectedly turn off (ABCA HDW CC st; Inst 19; or ABCB HDW CC st; Inst 30) unexpectedly return the Value 0, then both compressors shall be commanded off. After a predetermined waiting period (e.g, 10 seconds), the Grundfos load pump shall be commanded off and the belimo valve shall be closed. After a predetermined waiting period (e.g., 5 minutes, preferably adjustable through the Master Controller interface only), the heatpump shall be reenabled and if a demand is still present it shall be sequenced on. Should the shut down occur a predetermined number of times (e.g., 3 times) on the lead heatpump within the same operation cycle, a lead - lag switchover shall be initialized.

[0152] Unit does not Engage:

[0153] Should the compressors of the Heatpump not return an active status by a predetermined period (e.g., 30 seconds) after they have been commanded on, both compressors shall be commanded off, the load Grundfos pump shall turned off and the load belimo valve shall be closed. After a waiting Period of 5 min shall be reenabled and if a demand is still present it shall be sequenced on. Should the fault occur a predetermined number of times (e.g., 3 times) on the lead heatpump within the same operation cycle, a lead - lag switchover shall be initialized. Load Pump Critical Error / Failure:

[0154] Should the master controller receive a critical error or failure message from a load pump the corresponding heat pump shall be deactivated until the error is resolved.

[0155] Source Pump Critical Error / Failure:

[0156] Should the master controller receive a critical error or failure message from one of the source pumps then the corresponding source pump stack shall be deactivated until the error is resolved.

[0157] Parts List for FIGS. 1-11(c)

[0158] 10 heat pump

[0159] 14 circulation pump

[0160] 20 storage tank

[0161] 22 storage tank

[0162] 24 storage tank

[0163] 25 lower portion, storage tank

[0164] 27 upper portion, storage tank

[0165] 30 electric buffer device

[0166] 800 heat pump

[0167] 814 circulation pump

[0168] 818 valve

[0169] 820' storage tank

[0170] 822 storage tank

[0171] 824 storage tank

[0172] 825 lower portion, storage tank

[0173] 827 upper portion, storage tank

[0174] 830 electric buffer device

[0175] 1000 flowchart

[0176] 1004 - 1062 steps, flowchart

[0177] 1110 heat pump, lead 1120 heat pump, lag

[0178] 1124 air separation / expansion column

[0179] 1127 pump stacks, redundant

[0180] 1130 variable speed (circulation) pump

[0181] 1140 valve, fast reacting

[0182] 1160 storage tank, cold storage

[0183] 1170 storage tank

[0184] 1180 storage tank

[0185] 1190 electric buffer device

[0186] It will be understood that various modifications and variations are possible that incorporate the inventive aspects described herein, including the following appended claims.

Claims

Claims:

1. A method for improving the performance of a heat pump, the method comprising: supplying cold water from a cold water storage source to an inlet of the heat pump; and supplying the cold water through the heat pump at a low flow rate, thereby creating high lift while reducing energy consumption, thereby creating higher efficiency of the heat pump and with increased lift.

2. The method according to claim 1, wherein the method further comprises: operating the heat pump at its rated efficiency (COP) while supplying the cold water from the cold water source at the low flow rate through the pump, thereby significantly increasing the temperature of heated water leaving an outlet of the heat pump.

3. The method according to claim 1, further comprising supplying the cold water from at least one storage tank to a load side of the heat pump.

4. The method according to claim 1, wherein a heat exchanger is disposed within the heat pump, the heat exchanger being a counter flow heat exchanger.

5. The method according to claim 1, wherein the flow rate through the heat pump is less than 0.33 gpm per ton heat pump capacity.

6. The method according to claim 1, wherein the method further comprises monitoring the temperature of the cold water entering the heat pump and activating the heat pump when the monitored temperature is below a predetermined temperature.

7. The method according to claim 1, further comprising measuring the volume of stored cold water and enabling the heat pump only when a predetermined volume of desired cold storage is reached, and in which the volume of desired cold storage is below a predetermined temperature.

8. The method according to claim 7, in which the desired volume of cold storage water is determinable by the placement of temperature sensors within the cold storage source9. The method according to claim 4, in which water heated by the heat pump is supplied to at least one storage tank.

10. The method according to claim 1, in which a plurality of storage tanks is disposed in series with one another and in which the storage tank closest in the flow path to the heat pump is the cold water storage source.

11. The method according to claim 1, wherein the heat pump is used in a commercial or residential geothermally-based hot water heating system.

12. A geothermally-based system for creating hot water, the system comprising: a ground source of water; a heat pump for creating heated water; and at least one storage tank coupled to the heat pump and the ground source, in which the at least one storage tank initially contains cold water from the ground source to be supplied to the heat pump as a cold storage source wherein the cold water from the cold water source is supplied to the heat pump at a low flow rate to achieve high lift.

13. .The system according to claim 12, further comprising one or more controls for continually stabilizing the system based on user demand for heated water.

14. The system according to claim 13, in which the one or more controls comprise a controller and at least one sensor configured to monitor the temperature of water entering the heat pump, wherein the monitored temperature is compared to a stored setpoint temperature and in which the heat pump is activated based on a predetermined difference between the monitored temperature and the setpoint temperature.

15. The system according to claim 13, wherein the one or more controls further comprises at least one sensor for monitoring the temperature and volume of water in the cold storagesource in which the controller is configured to disable the system when the monitored temperature in the cold storage source is above a predetermined temperature or the monitored volume of cold water is below a predetermined volume.

16. The system according to claim 12, in which water heated by the heat pump is directed to the one or more storage tanks and wherein the low flow rate of water through the heat pump maintains stratification of heated and cold water within the one or more storage tanks including the cold storage source.

17. The system according to claim 12, in which the one or more storage tanks comprise at least two (2) storage tanks placed in series relative to one another, and in which the storage tank closest to the heat pump is the cold storage source.

18. The system according to claim 12, in which the heat pump utilizes a counter flow heat exchanger.

19. The system according to claim 14, comprising two or more heat pumps and in which the controller is configured to activate one or more of the heat pumps based on the monitored temperature of water entering a first heat pump as compared to the setpoint.

20. The system according to claim 14, comprising two or more heat pumps and in which the controller is configured to activate one or more of the two or more heat pumps based on a monitored volume of stored cold water.

21. The system according to claim 20, in which a first heat pump of the two or more heat pumps is activated based on a first predetermined volume difference between monitored water entering the first heat pump and the setpoint and in which a second heat pump of the two or more heat pumps is activated based on a second predetermined temperature or volume difference between the monitored temperature or stored volume of water.

22. The system according to claim 20, in which the first heat pump is activated based on a first predetermined volume of cold water stored which a second heat pump is activated based on a second predetermined temperature difference between the monitored temperature of water entering the first heat pump and the setpoint3. A process for producing hot water in a geothermally-based heating system, the process comprising: coupling a heat pump to one or more storage tanks, at least one of the one or more storage tanks containing cold water from a ground source; flowing cold water from the at least one storage tank through the heat pump at a low flow rate to create high lift in producing heated water; flowing the heated water to the one or more storage tanks and in which the low flow rate maintains stratification of the heated and cold water in at least one of the one or more storage tanks.

24. The process according to claim 23, wherein the one or more storage tanks comprise at least two storage tanks that are coupled to one another in series relation to one another.

25. The process according to claim 23, further comprising monitoring at least one of the temperature and the volume of the water entering the heat pump and at least one of comparing the temperature of the entering water to a setpoint temperature and the monitored volume to a predetermined volume, wherein the heat pump is activated based on a predetermined difference between at least one of the setpoint and monitored water temperature and the predetermined volume and monitored volume.

26. The process according to claim 25, further comprising activating a second heat pump in conjunction with the first heat pump when at least one of the monitored temperature and monitored volume of the entering water are based on at least one of a second predetermined difference between the setpoint and monitored water temperature and the predetermined volume and monitored volume of water.

27. The process according to claim 25, further comprising monitoring at least one of the temperature and volume of water in at least one of the one or more storage tanks and deactivating the system when at least one of the monitored temperature exceeds a predetermined temperature and the monitored volume exceeds a predetermined volume.

8. The process according to claim 25, comprising adding water from the ground source to the one or more storage tanks to provide a cold water storage source when the monitored temperature of water in the one or more storage tanks exceeds at least one of the predetermined temperature and predetermined volume.

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