Patent Application
20200049381
The present invention relates generally to the field of energy systems, and more particularly to energy systems for heating and cooling multiple buildings in a campus or community development.
When developing a sustainability plan for multiple buildings, based on a Green-House Gas and Energy Reduction Strategy, the energy plan often includes provisions for all buildings to be adaptable to an alternative sustainable energy source. Air conditioning is typically not incorporated into these alternative energy systems although it is often provided for separately in many geographic locations. For example, in certain suitable geographic locations, heat pumps and geothermal wells may be used for moderating the heating and cooling of the buildings.
Generally speaking, there are two basic types of heat pumps. A first type is an air source heat pump which draws its energy from the air, and also rejects its excess energy into the air. A second type of heat pump is a water source heat pump which draws its energy from a water or ground source, and also rejects or stores its excess energy into a water or ground source. As an illustrative example, excess heat from a heat pump can be used to meet the domestic hot water requirements of a building. For this purpose, variable refrigerant flow (VRF) heat pumps may be used. VRFs have been broadly used worldwide over the past 15 to 20 years, but it has only been the past 4 or 5 years that their use in North America has gained broad acceptance. A heat pump has a COP or “Coefficient of Performance” of about 3.0 to 5.5, or more depending on the diversity of demand and efficiency of the development. A COP of 3.0 means that for one unit of energy used, 3 units of energy will be produced. Typically, a water source heat pump is more efficient than an air source heat pump, as the water source has a more constant temperature range than does the air.
Heretofore, developments of neighborhood energy systems have all been based on a ‘low carbon’ external energy source, typically a high temperature system. These have been considered as opportunities for the creation of ‘utilities’ that can earn a regulated return on their investment of infrastructure including heating/energy plants. However, these systems ignore or exclude the demand for cooling or air conditioning at a time when buildings are becoming more efficient and air tight. The problem is that these ‘sealed’ buildings retain the thermal energy to a point where very little space heating is required although the demand for domestic hot water remains. To maintain or provide occupant comfort within these environments, cooling or air conditioning has become expected.
While utilizing both heating and cooling units to moderate a temperature and humidity within a building is known, depending on the size of the building, a fully automated energy system for each building may be cost prohibitive, and a common practice is therefore to release this excess energy into the atmosphere. Furthermore, optimizing energy utilization at a building level could leave opportunities for additional efficiencies unrealized.
Therefore, what is needed is an improved system and method which can optimize energy usage on a wider scale, within multiple buildings of a campus or development.
The present disclosure describes a “passive energy loop” system and method for optimizing energy usage within multiple buildings of a campus or development.
The term “passive energy loop” is used in the present disclosure to describe a novel integrated thermal energy recycling system that harvests thermal energy from multiple buildings, and shares excess energy with adjacent buildings within a campus or development, via a fluid filled ambient temperature ground loop, preferably embodied as one or more pipes passing through or connecting all of the buildings.
The energy loop provides energy storage and buffering of the daily temperature differentials between the heat pump systems and the buildings. The temperature of the fluid in the energy loop is uniquely tempered to achieve the optimal operating temperature in order to maximize the coefficient of performance for the water source heat pumps within the buildings that are connected to the energy loop. The temperature of the fluid in the energy loop is tempered by receiving or rejecting thermal energy from mechanical or electrical equipment that can include:
The temperature of the fluid in the energy loop is tempered to meet the optimal hourly, daily, and monthly temperature of the energy system to achieve the highest possible coefficient of performance for the water source heat pumps serving the spaces within the building or buildings connected to the energy loop.
The optimal temperature is determined by Predictive Analytics based on data monitored and collected from the elements that influence the selected temperature within the building spaces and systems that can include but are not limited to;
A computer system or systems control the temperature of the fluid in the loop in advance of the predicted demand on an hourly basis to achieve the optimal operating temperature of the water source heat pumps within the buildings.
In an aspect, the energy loop provides energy storage and buffering of the daily temperature differentials between the heat pump systems and the buildings. The temperature of the fluid in the energy loop is uniquely tempered to achieve the optimal operating temperature in order to maximize the coefficient of performance for the water source heat pumps within the buildings that are connected to the energy loop. The temperature of the fluid in the energy loop is tempered by receiving or rejecting thermal energy from various mechanical or electrical equipment.
This may include sewer heat recovery and transfer/rejection systems, geo-exchange or geo-thermal ground wells or other thermal storage including water tanks, pools, or specialized bulk materials, gas or electric heaters, fluid chillers, heat pumps, solar panels or solar tubes, and any other equipment or device capable of raising or lowering the ambient temperature of the fluid within the energy loop.
In an aspect, water source heat pumps harvest and recycle thermal energy from todays' inherently air tight efficient buildings, and repurpose it for other uses, such as heating hot water for circulation in the building. In turn, the domestic hot water can be recycled and regenerated through a building waste water heat recovery unit, to recapture the heat from the waste water.
In an embodiment, the building's heat pump condensing units are linked together by a fluid loop within each building, and between adjacent buildings by an ambient temperature ground loop or “passive energy loop”, as referenced above. Excess energy within the system can also be made available through a municipal sewer system to a downstream building within the campus or development, such that the downstream building can extract that heat utilizing its own sewer heat recovery and rejection unit.
Advantageously, the system and method described herein creates an ambient temperature ground or “passive energy loop” by utilizing either an integrated geothermal well field which stores the excess energy to meet seasonal demand, and or by a building scale or community scale sewer heat recovery and rejection unit that transfers energy to and from waste water passing through adjacent buildings.
A fully integrated “passive energy loop” system can achieve a COP of 5 to 7 times the amount of input energy, typically provided as an electrical input, and provide for building space heating and cooling, as well as domestic hot water needs.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or the examples provided therein, or illustrated in the drawings. Therefore, it will be appreciated that a number of variants and modifications can be made without departing from the teachings of the disclosure as a whole. Therefore, the present system, method and apparatus is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
The present system and method will be better understood, and objects of the invention will become apparent, when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings, wherein:
In the drawings, embodiments are illustrated by way of example. It is to be expressly understood that the description and drawings are only for the purpose of illustration and as an aid to understanding, and are not intended as describing the accurate performance and behavior of the embodiments and a definition of the limits of the invention.
As noted above, the present invention relates to a passive energy loop system and method.
The present disclosure describes a “passive energy loop” system and method for optimizing energy usage within multiple buildings of a campus or development.
The term “passive energy loop” is used in the present disclosure to describe a novel integrated thermal energy recycling system that harvests thermal energy from multiple buildings, and shares excess energy with adjacent buildings within a campus or development, via a fluid filled ambient temperature ground loop, preferably embodied as one or more pipes passing through or connecting all of the buildings.
The energy loop provides energy storage and buffering of the daily temperature differentials between the heat pump systems and the buildings. The temperature of the fluid in the energy loop is uniquely tempered to achieve the optimal operating temperature in order to maximize the coefficient of performance for the water source heat pumps within the buildings that are connected to the energy loop. The temperature of the fluid in the energy loop is tempered by receiving or rejecting thermal energy from mechanical or electrical equipment that can include:
The temperature of the fluid in the energy loop is tempered to meet the optimal hourly, daily, and monthly temperature of the energy system to achieve the highest possible coefficient of performance for the water source heat pumps serving the spaces within the building or buildings connected to the energy loop.
The optimal temperature is determined by Predictive Analytics based on data monitored and collected from the elements that influence the selected temperature within the building spaces and systems that can include but are not limited to;
A Computer system or systems control the temperature of the fluid in the loop in advance of the predicted demand on an hourly basis to achieve the optimal operating temperature of the water source heat pumps within the buildings.
In an aspect, water source heat pumps harvest and recycle thermal energy from todays' inherently air tight efficient buildings, and repurpose it for other uses, such as heating hot water for circulation in the building. In turn, the domestic hot water can be recycled and regenerated through a building waste water heat recovery unit, to recapture the heat from the waste water.
In an embodiment, the building's heat pump condensing units are linked together by a fluid loop within each building, and between adjacent buildings by an ambient temperature ground loop or “passive energy loop”, as referenced above. Excess energy within the system can also be made available through a municipal sewer system to a downstream building within the campus or development, such that the downstream building can extract that heat utilizing its own sewer heat recovery and rejection unit.
Advantageously, the system and method described herein creates an ambient temperature ground or “passive energy loop” by utilizing either an integrated geothermal well field which stores the excess energy to meet seasonal demand, or by a building scale or community scale sewer heat recovery and rejection unit that transfers energy to and from waste water passing through adjacent buildings.
A fully integrated “passive energy loop” system and method in accordance with the present invention can achieve a COP of 5 to 7 times the amount of inputs energy, typically provided as an electrical input, and provide for space heating and cooling, as well as hot water needs for all of the buildings. Thus, the purpose of the present system and method is to optimize the thermal energy recycling process to provide the highest COP possible, with the objective of using the least amount of inputs energy to regenerate the highest amount of heat. By harvesting and recycling thermal energy collected by today's air tight energy efficient buildings, and optimizing thermal energy recycling through all of the buildings within a campus or development, the system and method is able to achieve a COP for the buildings collectively, which otherwise would not be achievable individually.
The energy savings may be quantified through the analysis of the kilowatt hours of energy used per square meter of building per year (kwh/m2/yr), for all of the buildings connected by the “passive energy loop”.
An illustrative embodiments of the system and method will now be described with reference to the drawings.
Referring to
More generally, the “passive energy loop” 110 connects multiple energy transfer centers 130a, 130b, 130c within each building 120a, 120b, 120c, respectively, allowing the buildings 120a-120c to share and to store excess energy, or to reject excess energy to the “passive energy loop” 110, where it can be transferred to downstream energy systems of other buildings 120a-120c connected to the “passive energy loop” 110.
Still referring to
Still referring to
In an embodiment, the sewage heat recovery and transfer unit 150 is also connected to a building waste water drainage pipe 160 which receives waste water from each of the buildings 120a-120c. The sewage heat recovery and transfer unit 150 is configured to extract heat from the waste water flowing through the waste water drainage pipe 160, and to store it for transfer back into the passive energy loop” 110, as may be required. If the thermal energy from the waste water is not required at a given time, the waste water may be discharged to the municipal waste water system 170. The thermal energy collected from the municipal waste water system 170 may be controlled by a remotely controllable valve 172.
Still with reference to
In an embodiment, the system control center 200 is connected to a plurality of sensors located at each of the buildings and components to which it is connected. In addition, system control center 200 measures current ambient environmental conditions, and also stores historic environmental conditions within the campus or development. The system control center 200 therefore utilizes current and historical environmental data to create an optimal environment for all of the buildings 120a-120c over any given period of time. Historical and current conditions are used to anticipate the optimal temperature of the passive loop thereby tempering it to optimize the COP of the heat pumps.
Now referring to
Still referring to
In a preferred embodiment, the system 100 utilizes a variable refrigerant flow or VRF type water source heat pump for each of the water source heat pumps 210a-210c as illustrated in
VRF heat pumps are more efficient than heat pumps that have been typically used in earlier systems, which typically relied on air, ground or water sources as their energy source. Major suppliers of VRF heat pumps include Mitsubishi, Daiken and LG. A VRF heat pump can simultaneously recover heat or cooling being rejected by a fan coil unit, and use this thermal energy to simultaneously satisfy the demand from another unit in the same energy loop system.
Another type of VRF heat pump that may be used is the heat pump, which is a three pipe system of Hot, Ambient, and Cold liquid. This heat pump is controlled by a specialized valve, which allows all three pipes to be individually controlled. This type of heat pump is typically used in larger scale municipal projects, but may be scaled down to perform on a “micro” scale—for residential or commercial buildings—using multiple units to perform a similar function.
Electricity is the initial energy source used to power the VRF Heating and Cooling system within a building. This VRF system then primarily utilizes the thermal energy within a building as its primary energy source. The system reclaims or harvests the excess heat from cooling in one area of the building and transfers the heat to another via refrigerant lines. It also efficiently generates thermal energy through a condensing unit to provide heating or cooling. The condensing unit is the main component of a VRF heat pump to which the fan coil units are connected by refrigerant lines, and transfers thermal energy from and to the water/fluid loop within the building. The condensing unit can thus generate heat from or reject heat to the water loop.
The fluid loop transfers the thermal energy between floors in the building or between buildings. When connected to a ground loop, the excess energy can also be transferred and stored in the ground via a geo-exchange well field using the ‘earth’ like a ‘battery’. It effectively stores the excess heat in the summer for use in the winter. However, before any excess heat leaves the building, it can be captured by a heat pump to provide domestic hot water for the building. This domestic hot water is then used for showers, bathing, laundry and dishwashers before being drained into the sanitary sewer system. Prior to the waste water leaving the building, it may be captured by the sewer heat recovery system, where it is run through a heat exchanger followed by a heat pump which ‘recycles’ that heat back into domestic hot water. Buildings or developments within an urban setting can also tap directly into a larger municipal sewer main to extract or reject heat from the building system. An illustrative example is the SHARC Wastewater Energy Exchange System offered by SHARC Energy Systems.
Mixed use developments have a diversity of uses with heating and cooling loads making an ambient passive energy loop system more efficient. A commercial office building with a high percentage of vision wall glazing or a grocery store with its refrigeration requirements contribute significant heat or ‘thermal energy’ into the system.
An ambient temperature ground loop itself provides storage and ‘buffering’ of the daily temperature differentials between the heat pump systems and buildings. In an embodiment, the ground loop is a simple un-insulated pipe that transfers energy in the water throughout the system. When buried in the ground, it also uses the ground enroute to store energy. A computer controlled highly efficient pump system regulates the flow through this ‘passive energy’ loop for maximum efficiency. Predictive Analytics (PA) are programmed to ensure the system is optimized for daily, monthly and annual energy demands ensuring efficiency in all phases of operation.
A neighbourhood scale SHARC sewer heat recovery system can also be installed to capture the waste heat from the main sewer line before it leaves the development. This heat is used to raise the ambient temperature in the loop or store it in the ground via the geo-exchange wells. If there is an excess of heat in the system including the thermal storage, typically in the summer months, the ‘ SHARC’ will reject that excess heat from the entire system into the sewer line to maintain an ideal ambient operating temperature.
In an embodiment, the primary energy source used by the system is thermal energy harvested from the buildings using water source heat pump technology. With reference back to
In another embodiment, the passive energy loop 110 is tempered with thermal energy harvested from the buildings water source heat pumps or refrigeration systems and stored in geothermal wells and or rejected to sewer heat recovery and rejection systems in advance of demand to boost the efficiency of water source heat pumps.
Predictive analytics are used to determine the optimal temperature of the energy loop. For example, an optimal temperature for the passive energy loop is determined by predictive analytics based on data monitored and collected from the elements that influence the selected temperature within the building spaces and systems that can include but are not limited to thermostats, occupant load, building envelope performance calculations, water source heat pumps, fan coil units, building fans, electrical meters, calculated electrical loads of equipment including lighting, use of building spaces, temperature forecasts and ground temperatures. A computer is programmed to control the temperature of the fluid in the passive energy loop in advance of the predicted demand, e.g. on an hourly basis or on another more suitable time increment, to achieve the optimal operating temperature of the water source heat pumps within the buildings.
Data may be monitored and collected from multiple points. For example:
Water Source Heat Pumps and Fan Coil Units
Fan Coil Units
Building Units
Outdoor Temperature
Domestic Water
Domestic Hot Water
Building Heat Exchanger
The data collected as described above may be continually gathered throughout the year to determine any imbalance in the thermal energy demand within the passive energy system. Predictive analytics through machine learning are used to determine the thermal energy that will be required to balance or temper the passive energy loop for the optimization of the system. Input or rejection of thermal energy to or from the passive energy loop is managed over time in advance of the demand to optimize the delivery by avoiding ‘peak’ supply and or demand requirements.
The Passive Energy Loop effectively buffers the peak demand on the system by tempering the fluid within the loop in advance and over a longer duration to manage the energy required to deliver the thermal requirements of the connected loads.
In an embodiment, the system 100 optimizes the temperature of the fluid within the energy loop by optimizing the efficiency of the water source heat pumps, thereby increasing the Coefficient of Performance resulting in decreased building energy costs. The present system 100 addresses multiple conflicting systems in modern buildings, as previously mentioned in the Background section. Using existing water source heat pump technology, the system 100 harvests the excess thermal energy within the buildings, thereby providing cooling. The thermal energy is also recycled within the building and regenerated for domestic hot water. Excess energy is shared via a fluid energy loop within the building and via a ground loop to other buildings within the ‘community’ or stored in geothermal wells to meet seasonal demands.
In comparison to prior art solutions, the present system 100 is more efficient by tempering the fluid in the building loop or ground loop in advance of the demand from the water source heat pumps within the buildings. It draws on the thermal energy stored in the geothermal wells and or from the waste water heat recover/rejection system. Predictive analytics would be used to determine the optimal temperature of the energy loop to maximize the efficiency of the units thereby increasing the Coefficient of Performance of the Passive Energy System.
Advantageously, multiple building systems are integrated into a holistic passive energy system that optimizes the recycling of thermal energy within the buildings, and between the buildings of a campus or development, to achieve a Coefficient of Performance or COP that is several times greater than the sum of the individual buildings. As an illustrative example of a development, a passive energy system may be incorporated into a design of a multi-lot, multi-acre development of over 1,000,000 ft.2 mixed us residential community, with a planned ambient temperature energy loop connecting all of the buildings within the development. However, the system can also be scaled down to a much smaller development, or similarly scaled up to cover even larger communities.
Excess thermal energy is extracted from todays' efficient airtight buildings and recycled to satisfy demand within building, for heating and cooling and for domestic hot water, before sharing the excess thermal energy with other buildings on the passive energy loop, or stored in ground. Excess energy is transferred via an existing municipal waste water system to supply downstream demand.
By way of example, and not by way of limitation, a possible implementation of the passive energy loop 110 is a DESS 10 pipe, which is a 2 pipe system of a warm and cool loop with a 3 way valve that manages the flow of energy between them.
This passive energy system achieves the sustainability objectives of an Energy and GHG Reduction Strategy required as a condition of development. It contributes significantly to the LEED Gold objectives and will likely achieve the Near Net-Zero Energy reduction targets being set by certain municipalities, including the City of Vancouver.
Advantageously, as this system is based on heat recovery, there is little or no requirement for fossil fueled (i.e. natural gas) heating systems. Rather, existing thermal energy which may otherwise be wasted is converted through highly efficient heat pumps and condensers providing COPs three to five or more times higher than high efficiency gas fired boilers can provide. However, each building may have an efficient condensing gas boiler or electric heater that would be used as a standby for domestic hot water or to satisfy a peak heating demand.
The system and method described here are suitable for any multi-building projects or developments where an alternative energy source that will reduce their GHG (Green House Gas) emissions is desired. This system moves towards a near ‘Net Zero’ emissions solution that recovers or harvests excess thermal energy, and minimizes the need for any energy sources that would add to GHG.
Thus, in an aspect, there is provided a system for optimizing energy utilization in a multi-building development, comprising: a passive energy loop comprising a continuous fluid filled pipe; one or more thermal energy transfer centers connecting each of a plurality of buildings in the multi-building development onto the passive energy loop; and a system control center adapted to control the plurality of thermal energy transfer centers to extract excess thermal energy from or input required thermal energy to each one of the plurality of buildings, thereby to buffer the temperature differentials, improve energy utilization, and reduce greenhouse gases produced by the plurality of buildings in the multi-building development.
In an embodiment, each of the thermal energy transfer centers includes one or more heat pumps, and wherein the system control center is further adapted to determine an optimal temperature in the passive energy loop to maximize a coefficient of performance for the one or more heat pumps in each of the thermal energy transfer centers.
In another embodiment, the heat pumps are water source heat pumps connected directly or indirectly to the passive energy loop via a thermal energy coupling.
In another embodiment, the optimal temperature in the passive energy loop is achieved by regulating the thermal energy transferred to or from the passive energy loop for a plurality of equipment within each of the plurality of buildings capable of raising or lowering the ambient temperature of the fluid within the passive energy loop.
In another embodiment, the equipment comprises a sewer hear recovery unit.
In another embodiment, wherein the equipment comprises a geo-exchange or geo-thermal ground well.
In another embodiment, the equipment comprises a thermal storage unit including water tanks, pools, or specialized bulk materials.
In another embodiment, the equipment comprises gas or electric heaters, fluid chillers, or heat pumps.
In another embodiment, the equipment comprises solar panels or solar tubes.
In another embodiment, the system is adapted to adjust the temperature of the fluid in the passive energy loop is tempered to meet changing requirements over time.
In another embodiment, the system is adapted to adjust the temperature on an hourly basis to optimize the coefficient of performance for any water source heat pumps in the one or more thermal energy transfer centers connecting the buildings to the passive energy loop.
In another embodiment, the system is adapted to adjust the temperature based on one or more sensors and data from each of the buildings.
In another embodiment, the one or more sensors include a plurality of temperature and humidity sensors monitoring ambient temperature and ground temperature.
In another embodiment, the data includes occupant load and building envelope performance calculations.
In another embodiment, the one or more sensors include a plurality of sensors monitoring performance data from one or more of water source heat pumps, fan coil units, building fans, electrical meters, calculated electrical loads of equipment, and utilization of building space.
In another embodiment, the system is adapted to buffer peak energy requirements by tempering the passive energy loop outside peak energy times, thereby decreasing load on infrastructure requirements.
In another embodiment, the system is further adapted to perform predictive analysis based on measured data and seasonal temperature forecasts.
In another embodiment, the system is adapted to perform predictive analytics based on data collected from room thermometers and thermostat temperature settings.
In another embodiment, the system is adapted to perform predictive analytics based on data collected from occupant sensors, use of building spaces, and building envelope performance calculations.
In another embodiment, the system is adapted to collect and utilize historical performance and usage data to predict seasonal demands.
While illustrative embodiments have been described above by way of example, it will be appreciated that various changes and modifications may be made without departing from the scope of the system and method, which is defined by the following claims.
