Patent Application
20180010453
The present invention relates to the field of heating systems, and, more particularly, to a hydro excavation heating system and related methods.
In northern climates, frozen ground is a problem for the construction industry during the winter months. Cold winter temperatures can cause water and sewer pipes to freeze. Frozen ground also interferes with any earth moving operation such as trenching, excavating for foundation footings, leveling for a concrete slab, or digging a gravesite. Consequently, in northern climates, mobile ground heating or thawing systems are known.
One common type of mobile heating system known in the prior art comprises a kerosene burner and a fan for discharging large volumes of heated air into a temporary enclosure which confines the heated air above the area which is to be thawed. Such systems are also used to blow heated air into an unfinished structure during later phases of construction. However, when such systems are used in this latter application, they are found to have a significant problem with water vapor, carbon dioxide, and other combustion products, which build up inside the unfinished structure. It is not desirable to expose workmen for many hours to the combustion products which emanate from such devices. Further, since water vapor is one of the principal byproducts of combustion, condensation of the water vapor in the structure can be a problem in cold weather. Such systems are also known to have a low thermal efficiency and are expensive to run because of high fuel consumption.
In another type of mobile ground heating or thawing system, a boiler, a pump and a ground heat exchanger in the form of a hose, including a plurality of ground-engaging probes, are all filled with a heat transfer fluid. The heat transfer fluid is pumped from the boiler through the hose the probes for the purpose of transferring heat to the ground or to a structure. Systems which use such a fluid coupling between the ground and a boiler are known to have better heat transfer efficiency than those employing a burner and a fan. Such systems also provide the advantage of being able to more precisely apply heat to a desired area. In such systems, heat is applied to the ground with fluid-filled rods, which are inserted into holes which are drilled into the frozen ground, or with fluid-filled hoses which are laid over the ground and covered with a suitable quantity of sand and/or other insulating materials.
In view of the foregoing background, it is therefore an object of the present invention to provide.
This and other objects, features, and advantages in accordance with the present invention are provided by a hydro excavation heating system that includes an internal combustion engine having an exhaust gas stream, a heat exchanger coupled to the exhaust gas stream and configured to heat hydro excavation water by transferring heat from the exhaust gas stream to the hydro excavation water circulating therethrough, and a tank for storing the hydro excavation water. The system also includes a water pump having an inlet coupled to an outlet of the tank storing the hydro excavation water, a hydro excavation hose coupled to an outlet of the water pump, and a coupling coupled to the hydro excavation hose and to an inlet of the heat exchanger to define a closed circulation path through the system when heating the hydro excavation water, where the coupling is configured to disconnect from the heat exchanger in order to use the hydro excavation water during a hydro excavation operation.
In another embodiment a method of heating hydro excavation water is disclosed. The method includes heating hydro excavation water by transferring heat from an exhaust gas stream of an internal combustion engine to the hydro excavation water using a heat exchanger, pumping the hydro excavation water from the heat exchanger to a tank, and pumping the hydro excavation water from the tank through a hydro excavation hose. The method also includes returning the hydro excavation water to the heat exchanger and continuing to recirculate the hydro excavation water through the heat exchanger until a temperature of the hydro excavation water exceeds a threshold temperature.
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and prime notation is used to indicate similar elements in alternative embodiments.
Referring initially to
A heat exchanger 106 is secured to the exhaust piping 104 and serves as a mechanism to transfer the heat in the exhaust gases to the hydro excavation water. A recirculating pump 108 is coupled in fluid communication with the heat exchanger 106 via hot line piping 110. The hot line piping 110 conveys the heated hydro excavation water from the heat exchanger 106 to the water tanks 112a and 112b. The recirculating pump 108 is configured to pump the hydro excavation water continuously from the heat exchanger 106 to the tanks 112a, 112b and hydro excavation hose 120, and back to the heat exchanger 106. The hydro excavation hose 120 is shown schematically being stored on a hose reel in
The water tanks 112a, 112b are in fluid communication with a secondary temperature sensor 116 via tank outlet piping 114. Downstream of the secondary temperature sensor 116 is a hydro excavation pump 118, which is coupled to a first end of the hydro excavation hose 120. A second end of the hydro excavation hose is coupled to a quick connect coupling 122. The quick connect coupling 122 is configured so that the second end of the hydro excavation hose 120 can be disconnected from recirculating the hydro excavation water back to the heat exchanger 106 and the hydro excavation water can be used for hydro excavation. When the second end of the hydro excavation hose 120 is connected with the quick connect coupling 122, the hydro excavation water is circulated back to the heat exchanger 106.
The quick connect coupling 122 is coupled to a primary temperature sensor 132 and downstream of the primary temperature sensor 132 is a control valve 124. The control valve 124 is configured to control the flow of the hydro excavation water through the heat exchanger 124. When the control valve 124 is in a first position, the hydro excavation water is directed to the heat exchanger 106. In a second position, the control valve 124 directs the hydro excavation water to bypass the heat exchanger 124.
The hydro excavation heating system 100 includes a controller 130 having a processor coupled to a memory. The controller 130 is coupled to the primary and secondary temperature sensors 122, 132 and the control valve 124. The controller 130 is configured to operate the control valve 124 in order to control the rate of flow of the hydro excavation water to the heat exchanger 106 by comparing the first temperature from the primary temperature sensor 132 to the second temperature from the secondary temperature sensor 116 and changing the rate of flow in response thereto. For example, once the temperature of hydra excavation water is at the desired temperature or exceeds a threshold temperature, the controller 130 signals the control valve 124 to move to the bypass position in order to direct the hydro excavation water to divert to the bypass piping 126 around the heat exchanger 106. A one-way valve 128 is in fluid communication between the bypass piping 126 and the hot line piping 110.
Referring now to
As shown in
Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings.
Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims.
