Patent Abstract:
A heating, ventilating, and air-conditioning system utilizes a pressurized fluid to generate heat and drive the components of the system. As the pressurized fluids turns the components heat is generated. The heat in the fluid can be transferred to air via a heat exchanger and/or a radiant heater. A generator is turned by the pressurized fluid and generates electricity for an auxiliary fluid heater and operation of the system and/or backfed to a battery or power grid.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/547,100, filed Feb. 24, 2004. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The present invention relates to heating, ventilating, and air conditioning (HVAC) systems that utilize a pressurized fluid for generating heat, air conditioning, and electric current.  
         [0004]     2. Description of the Related Art  
         [0005]     Many applications require the generation and transferring of heat. Examples that require the generation of heat to warm a fluid medium (i.e. water or air) include systems for heating buildings, clothes dryers, and water heating units. Such known configurations utilize various heat sources. Known heat sources include electrical resistance elements and oil, natural-gas, coal, and other burners.  
         [0006]     Electrical resistance elements are inexpensive, develop high temperatures in short time periods, and can be readily supplied with electrical operating power. However, such resistance elements have high power consumption rates and are therefore costly to operate compared to other available heating systems. Oil and gas burner units can be more cost effective to operate than electrical resistance based units, but oil and gas burner units also have their drawbacks such as limitations based on availability of the respective combustible fluids in particular localities, the potential for operating cost fluctuations based on various global factors and the bulkiness of the overall units.  
         [0007]     The above problems show that each of the commonly known heating configurations has its associated advantages and disadvantages. In general, operational efficiencies must be compromised if operational costs are to be minimized. Furthermore, the overall compactness of prior-art units represents a significant limitation.  
         [0008]     U.S. Pat. No. 5,979,435 proposes a solution using a heated liquid medium. The heated liquid medium is pressurized, released, and heated through friction. The heated fluid is used to donate heat to other systems.  
         [0009]     If hydraulic fluid is used in a system like the one proposed in U.S. Pat. No. 5,979,435, many limitations become obvious. While the patent teaches using water and air as fluids, hydraulic fluid is required for reasons of heat capacity and pressurization. To create a heat transfer equaling conventional heaters, a system utilizing hydraulic fluid requires pressures above 17.25 mPA (2500 psi) and temperatures above 140° C. However, at these temperatures and pressures, hydraulic fluid breaks down. Furthermore, when heated by the frictional heaters, the hydraulic fluid foams. In addition, the pumps needed to create the pressure cause cavitation, which adds gas to the fluid. When gas bubbles exist in the plumbing, hammering and knocking occurs. When the gas is vented from the hydraulic fluid, the fumes are noxious. Finally, hydraulic fluid is toxic and poses risk whenever applied near people, especially, in homes.  
         [0010]     Experiments have shown that a system taught by U.S. Pat. No. 5,979,435 run with hydraulic fluid at a temperature below 140° C. to avoid break down only allowed 0.189 m 3 /s (400 ft 3 /min) of air to be heated. This amount of heat exchange is not sufficient for most household applications.  
         [0011]     Therefore, there exists a need for a heating system that uses a liquid medium for heat that supplies sufficient heat within traditionally sized systems to replace traditional systems and that does not produce noxious fumes and risks of toxic spills.  
       SUMMARY OF THE INVENTION  
       [0012]     An object of the invention is to develop an all-electrical based (i.e. non fossil fuel burning) heating system with a low operating cost. The system will take in cold, fresh, moist air and heat it to a comfortable room temperature without significantly removing the moisture from the air. This system not only makes heat, but also provides energy for additional tasks. The system raises the fluid temperature to compensate for increases in work output. The heating system receives cold air at very low temperatures with the capacity to raise the indoor temperature to 80° C. or higher. This will allow for greater fresh air intake and stale air venting.  
         [0013]     A generator is also a component of this system. The generator provides electricity that can be used by an auxiliary heater. The generator is powered by a turbine that is turned by the pressurized fluid. The electricity created by the generator also can power the power controller (i.e. CPU), the electric-powered valves, and the drive pump. Unused power can be stored in batteries or fed to the power grid. By recapturing some of the power input, the generator directly reduces the primary electrical power required to run the heating system, as well as mechanically heat the fluid.  
         [0014]     The system operates at lower pressures than normally used in hydraulic systems. The system has an electric motor that drives a fluid pump. This pump pressurizes the system and provides flow for a fluid motor that turns a gearbox that provides the proper RPM for the generator. The fluid then flows to a second fluid motor that mechanically turns the blower. The blower draws air through an air filter, through a heat exchange unit, and forces it through the duct system into areas to be heated. If the required fluid temperature drops below a minimum, an auxiliary electrical heater element brings the fluid to the required temperatures as controlled by a thermostat. Next, the fluid flows through the heated air exchange unit to a ported valve system that will allow the warm fluid to continue the heating process by an optional or primary radiant heating system. The fluid then flows back to the reservoir and the initial fluid drive pump to repeat the next cycle.  
         [0015]     In accordance with the objects of the invention, a heating system is provided. The heating system includes a fluid, tubing, a drive pump, a generator, and an air handler. The fluid is pressurized by the drive pump and circulated through the tubing. The generator creates electricity and is connected to the tubing downstream of the drive pump. The pressurized fluid turns the generator and thereby heats the pressurized fluid. The air handler is connected to the tubing downstream of the generator and has a heat exchanger and a fan. The heat exchanger is heated by the fluid. The fan is turned by the fluid and thereby heats the fluid and blowing air to be heated through the heat exchanger.  
         [0016]     The fluid is a proprietary fluid. For use in cold locations, the fluid should have a pouring temperature no greater than −43° C. To guarantee that the fluid continues to work even in abnormally high, yet foreseeable, temperatures, the fluid should have a boiling point greater than 316° C. To provide quiet operation and prevent formation of noxious fumes, the fluid should not foam or cavitate under operating conditions. Specifically, the fluid should not foam and cavitate at a temperature below 60° C. and a pressure below 3.45 mPa.  
         [0017]     A further object of the invention is to provide a heating system that has enough heat capacity to heat at least 0.236 m 3 /s, and more preferably at least 0.473 m 3 /s, of air to at least 30° C. above an intake temperature.  
         [0018]     It is a further object of the invention to provide a heater that heats air immediately upon startup. To prevent a lag between drive-pump startup and heat, an electrical heater can be disposed in the heat exchanger. The heat exchanger heats the fluid to a set temperature, preferably at least 37.8° C. The electrical heater can also be used to supplement the heat of the fluid during sustained operation that requires extra amounts of heat capacity. A further object of the invention is to provide an electrical heater that heats the fluid to at least 43.3° C. When the fluid is heated to 43.3° C., for most airflows, the air is heated to at least 40.6° C.  
         [0019]     In accordance with a further object of the invention, electricity generated by the generator can be used to power the electrical heater. Alternatively, the electrical heater can be fed by a primary source such as a battery or power grid.  
         [0020]     In accordance with a further object of the invention, a radiant heater can be connected to the tubing downstream of the air handler. The radiant heater would include a radiator that allows heat to be radiated from the fluid. The radiant heater can be buried in the flooring or walls.  
         [0021]     Other features which are considered as characteristic for the invention are set forth in the appended claims.  
         [0022]     Although the invention is illustrated and described herein as embodied in a pressurized liquid and a fluid-turbine generator, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.  
         [0023]     The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0024]     The FIGURE is a partial schematic and partial diagrammatic view of the system according to the invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]     Referring now to the single FIGURE of the drawing, it is seen that a heating system has a (non-electrical) circuit formed by a power pack, which is connected to an air handler, which is connected to a radiant heat module, which is connected to the power back.  
         [0026]     The sole FIGURE of the application shows a preferred embodiment for a heating and cooling system. Generally, except where specified below, the heating and cooling system is formed by a closed (i.e. recycling) circuit of piping that carries a fluid. The heating and cooling system includes several subsystems: a power pack  100 , an air-conditioner cycle  200 , an air handler  300 , and radiant heater  400 .  
         [0027]     The power pack  100  includes a fluid tank  101 . The fluid tank  101  acts as a reservoir for collecting fluid, holding extra fluid, and providing fluid as needed. In addition, the fluid tank  101  allows a space for expansion of the fluid upon return. The fluid tank  101  has a fluid tank outlet  102 . The fluid tank outlet  102  is connected to a first drive pump  103 . The first drive pump  103  pressurizes the fluid through the system. Pressures between 2.07 Mpa and 3.45 Mpa (i.e. 300-500 psi) are generated by the first drive pump  103 . The first drive pump  103  is powered by a motor  104 . The motor  104  is preferably an electrical motor. In particular, an axial field motor like the one taught in U.S. Pat. No. 5,982,074 is used. The horsepower of the drive pump  103  and motor can be tailored to the application. For applications, requiring greater heat exchange, a larger horsepower motor  104  is used.  
         [0028]     The accelerated fluid reaches a generator junction  105  in the piping. The accelerated fluid can be passed through a generator  106  and/or a bypass valve  107 . The bypass valve  107  diverts flow from the generator  106  when open. When the bypass valve  107  is closed, the fluid turns a generator turbine  108 . The generator turbine  108  is mechanically coupled to a gearbox  109 . Preferably, the gearbox  109  is a speed doubler. The gearbox  109  turns the generator  106 . The generator  106  produces electrical current as it is turned. The generator  106  is preferably an axial field generator, like those described in U.S. Pat. No. 5,982,074, which is incorporated by reference. In alternative embodiments, the generator can be an alternator or other means for converting mechanical energy to electrical energy. The generator  106  is connected to a power controller  110 . The fluid leaves the generator and/or bypass valve at the generator junction  111 .  
         [0029]     The generator  106  restricts flow through the generator turbine  108  and creates friction, which increases the fluid temperature in the system. This heating reduces the dependence on an ancillary heater (i.e. heater  307 ). When used, the generator  106  and the output power controller  110  direct power as required to optimize and reduce the demand on the incoming primary power. The power controller  110  can open and close the bypass valve  107  to throttle the generator  106 .  
         [0030]     The power controller  110  controls the generator fluid bypass valve  107  to adjust the speed of the generator  106  as required and buffer system on/off cycles. The power controller  110  thereby optimizes the output power of the generator  106  and reduces the required primary power.  
         [0031]     From the generator junction  111 , the fluid flows to the air-conditioner split  201 . An air-conditioner control valve  202  controls the flow of fluid that reaches a chiller  204 . An air-conditioner bypass valve  203  diverts flow from the chiller  204  when the air-conditioner  200  is not operating. An air-conditioner check valve  205  prevents fluid from flowing backward into the chiller  204 . The fluid flowing from the chiller  204  and/or the air-conditioner bypass valve  203  joins at the air-conditioner junction  206 .  
         [0032]     Although not detailed, the air conditioner involves a typical air conditioner system with a refrigerant compressor, a blower, and an evaporator/heat exchanger. The coolant system is separate from the pressure fluid system. The compressor motor and air-conditioner blower are powered by the pressurized fluid. In a further possible embodiment, refrigerant for the air-conditioner is the same fluid that is pressurized and used throughout the system.  
         [0033]     From the air-conditioner junction  206 , the fluid reaches the air handler  300  at the air-handler split  301 . A third drive pump  302  is downstream of the air-handler spit  301 . A bypass valve  303  allows diversion of fluid from the third drive pump  302 .  
         [0034]     The air handler  300  includes a cabinet  304 . The cabinet  304  is sized to comply with standard sized air handlers. Within the cabinet  304 , a blower assembly  305  is disposed. The blower assembly  305  includes a fan  306 , which is preferably a drum fan. The fan  306  is connected to a fan turbine  302 . The fan turbine  302  is turned by the pressurized fluid. As it spins, the fan turbine  302  turns the fan  306 . As the fan turbine  302  spins the fluid becomes further heated. The fan  306  pushes air through the heat exchanger  308 . An electrical heater  307  heats the fluid if necessary; typically the electrical heater  307  is necessary if extremely low temperatures exist or when the electric motor has not been active for a long time. The heat exchanger  308  heats the air pushed by the fan  306 . The fluid pressure drops significantly after passing through the heat exchanger  308 . An air filter  309  filters the heated air following the heat exchanger  308 . The heated air passes through a plenum, which is not shown, and can be distributed throughout a building by air ducts, which are also not shown.  
         [0035]     The heat exchanger  308  is preferably a multi-staged unit. The fluid flow is controlled so a maximum heat exchange can take place between the fluid and air flow. The moisture level in the incoming air flow is maintained and will not be sufficiently altered by the heating system. However, if moisture control is required, a humidifier can be added to the air handler  300 .  
         [0036]     Although  FIG. 1  shows one heat exchanger, more heat exchangers can be included to increase the heat transfer.  
         [0037]     In addition, multiple air handlers  300  can be connected in parallel or series with each other. By having more than one air handler  300 , more zones can be heated. Furthermore, each air handler can have a respective thermostat  307  controlling it.  
         [0038]     Multiple thermostats  307  allow for zones within to be heated to different temperatures.  
         [0039]     After the air handler  300 , the fluid reaches the radiant heater  400 . The radiant heater  400  has a radiant heater split  401 . At the radiant heater split  401 , the fluid can be diverted between the radiator  402  and the radiant heater bypass  403 . A radiant-heater bypass valve  404  controls the flow through the radiant-heater bypass  403 . When the radiant-heater bypass valve  404  is open, the fluid flows through the radiant-heater bypass  403 . When the radiant-heater bypass valve  404  is closed, the fluid cannot flow through the bypass  403 . Similarly, a radiator valve  405  controls flow of the fluid through the radiator  402 . The radiator  402  is formed by at least one pipe; when more than one pipe is used, the pipes are typically disposed parallel to each other. For radiant floor heating, the radiator  402  is disposed within the flooring, foundation, or wall of the room to be heated. A radiator check valve  406  is placed downstream from the radiator  402  and prevents the fluid from flowing backward into the radiator  402 . The radiator bypass  403  joins fluid from the radiator  402  at the radiant-heater junction  407 .  
         [0040]     From the radiant heater  400 , the fluid returns to an inlet  110  of the fluid tank  101  of the power pack  100 . The fluid collects in the fluid tank  101 . A fluid filter  112  interconnects the return  500  and the fluid tank  101 . The fluid filter  112  strains particles in the fluid and separates them from the fluid entering the fluid tank  101 .  
         [0041]     Steel hydraulic piping is used to connect the power pack  100  to the air-conditioner  200  and to the air handler  300 . Pressures after the air handler  300  are significantly less 0.069 Mpa to 0.10 Mpa (10 to 15 psi) are typical. The radiant heater  400  and the return  500  can be manufactured from standard copper plumbing because the fluid has significantly less pressure.  
         [0042]     The preferable fluid is a fluid sold under the trade name HCL-3. The fluid is preferably a proprietary high-viscosity, biodegradable, non-toxic, non-hazardous, synthetic hydraulic and heat transfer fluid. The fluid is made with the thermally and oxidatively stabile non-toxic and non-hazardous base fluids. The combined fluid is further enhanced with additives that extend the fluid life and thermal performance over other competitive synthetic fluids. Proprietary chemistry for this product also provides for even higher operating temperatures, in both open and closed systems. The fluid is approved by the USDA for H-1 applications and fully complies with the requirements of the FDA Rule § 178.3570 (21 CFR 178.3570). This is a biodegradable fluid, which is non-toxic and non-hazardous, and does not form carbon in most specifications. The properties of the fluid are Viscosity cSt @ 316° C. (600° F.) using Test Method D-445. The fluid has a pour point −43° C. (−45° F.)  
         [0043]     The power controller  110  preferably includes a central processing unit that evaluates and controls the various functions of the system.  
         [0044]     For example, thermostats  207 ,  310 , and  408  are connected by wiring to the power controller  110 . When the thermostat  207  detects a temperature above a set temperature, the power controller opens the air-conditioner control valve  202  and closes the air-conditioner bypass valve  203 . In addition, the power controller  110  activates the electric motor  104  to pressurize the fluid. When the thermostat  207  detects that the room temperature has reached the set point, the power controller closes the air-conditioner control valve  202  and opens the air-conditioner bypass valve  203 . If no other system requires pressurized fluid, the power controller  110  deactivates the electric motor  104 .  
         [0045]     If the thermostat  307  detects a room temperature below a set point, the power controller  110  activates the air handler  300 .  
         [0046]     The power controller  110  activates the air handler  300  by powering the electric motor  104  to pressurize the fluid. The power controller  110  closes the air-handler bypass valve  303 . The temperature of the fluid at the heat exchanger  308  is measured by the thermocouple  311 . If the fluid temperature at the thermocouple is too low, the electric heater  307  is activated by the power controller. The power controller  110  closes the bypass valve  107  to divert fluid through the generator  106 ; the generator  106  provides the electrical power for the electric heater  307 . When the thermostat  307  detects that the room temperature has reached the set point, the power controller opens the air handler bypass  303  and deactivates the heater  307  if the heater  307  is on. If no other system requires pressurized fluid, the power controller  110  deactivates the electric motor  104 .  
         [0047]     The power controller  110  activates the radiant heater  400  when the thermostat  408  reads a room temperature below a set point. The power controller  110  activates the electric motor  104  to pressurize the fluid. After the fluid passes the generator  106  and the heat exchanger  308 , the fluid will have gained enough heat to work as a medium for radiating heat. The power controller  110  opens the radiator valve  405  and closes the radiant-heater bypass valve  404  to allow the heated fluid to flow through the radiator  402 . When the room temperature reaches the set point, the power controller  110  closes the radiator valve  405  and opens the radiant-heater bypass valve  404 . If no other system requires pressurized fluid, the power controller  110  deactivates the electric motor  104 .

Technology Classification (CPC): 5