Condensing unit configuration system

A system and method for configuring a condensing unit for a cooling system includes inputting one of a cooling system characteristic, a condensing unit characteristic and a compressor characteristic for the cooling system, applying embedded design rules and accessing a condensing unit database of component attributes and their relationships. A base condensing unit is determined based on the one of a cooling system characteristic, a condensing unit characteristic and a compressor characteristic for the cooling system. The method further includes selecting various accessories of the condensing unit for customizing the base condensing unit based on the particular application.

FIELD OF THE INVENTION

The present invention relates to condensers, and more particularly to configuring a condensing unit for an air-conditioning or refrigeration system.

BACKGROUND OF THE INVENTION

Traditional cooling systems, such as refrigeration and air-conditioning systems, include a compressor, a condensing unit, an expansion valve and an evaporator. The compressor compresses gaseous refrigerant exiting the evaporator and discharges the high pressure refrigerant to the condensing unit. The condensing unit operates as a heat exchanger enabling heat transfer from the gaseous refrigerant to a heat sink (e.g. air or water). The refrigerant condenses within the condensing unit and a state change occurs from gas to liquid. The liquid refrigerant exits the condensing unit and flows to the evaporator through the expansion valve. The evaporator also operates as a heat exchanger enabling heat transfer from the atmosphere surrounding the evaporator to the liquid refrigerant. As the heat transfer occurs, the temperature of the refrigerant increases until a state change occurs from liquid to gas. The gas refrigerant is drawn into the suction side of the compressor and the cooling cycle continues.

The condensing unit can be one of an air-cooled condensing unit (ACU) or a water-cooled condensing unit (WCU). An ACU typically includes a fin-tube refrigerant-to-air heat exchanger, an air flow device such as a fan motor and fan blade and associated controls (not shown). In the case of an ACU, air provides the heat sink enabling heat transfer from the condensing unit. A WCU typically includes a refrigerant-to-water heat exchanger and associated controls (not shown). In the case of a WCU, water provides the heat sink enabling heat transfer from the condensing unit.

The particular configuration of the condensing unit depends on various system parameters including the compressor, heat exchanger, controls, refrigerant type, operating temperatures and the like. As a result, repetitive design and testing steps are typically required to provide an appropriate condensing unit for a given cooling system.

SUMMARY OF THE INVENTION

The present invention provides a system and method for knowledge-based configuration of a condensing unit for a cooling system. The method includes inputting one of a cooling system characteristic, a condensing unit characteristic, a compressor characteristic for the cooling system and accessing design rules and a database of valid component relationships and their attributes. A base condensing unit is determined based on the one of a cooling system characteristic, a condensing unit characteristic and a compressor characteristic for the cooling system. The method further includes selecting desired accessories for customizing the base condensing unit.

In one feature, the cooling system characteristic includes a cooling system capacity.

In another feature, the cooling system characteristic includes a cooling system horsepower.

In another feature, the cooling system characteristic includes design criteria. The design criteria includes at least one of a group consisting of refrigerant type, temperature range, evaporator temperature, normal air temperature, maximum air temperature, frequency, phase and voltage.

In another feature, the condensing unit characteristic includes a condensing unit model number.

In another feature, the compressor characteristic is a compressor model number.

In still another feature, the method further comprises determining the price of the configured condensing unit and outputting a quote (spec) sheet summarizing key characteristics and bill-of-materials of the condensing unit cost.

In another feature, the accessories include at least one of a group consisting of an accumulator, a filter drier, a moisture indicator, a shrader fitting, a discharge line thermostat, a crankcase heater, a monel discharge tube, a conduit, a service cord, a base mounted electrical box, condenser end covers, a fan guard and a defrost timer.

In another feature, the method further comprises determining high and low side options such as low ambient controls, pressure vessel (receiver) and shut-off valves.

In yet another feature, the method further comprises determining various pressure control options for the base condensing unit.

Another feature provides embedded rules to verify if the configuration meets Underwriter Laboratories safety regulations.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now toFIG. 1, a generic cooling system10includes a compressor12, a condensing unit14, an expansion valve16and an evaporator18. The compressor12is controlled by a controller20and compresses gaseous refrigerant exiting the evaporator18. The compressor12discharges the high pressure refrigerant to the condensing unit14. The condensing unit14operates as a heat exchanger enabling heat transfer (Q1) from the gaseous refrigerant to a heat sink (e.g., air or water). The refrigerant condenses within the condensing unit14and a state change occurs from gas to liquid. The liquid refrigerant exits the condensing unit14and flows to the evaporator18through the expansion valve16. The evaporator18also operates as a heat exchanger enabling heat transfer (Q2) from the atmosphere surrounding the evaporator18to the liquid refrigerant. As the heat transfer occurs, the temperature of the refrigerant increases until a state change occurs from liquid to gas. The gas refrigerant is drawn into the suction side of the compressor12and the cooling cycle continues.

The condensing unit configurator is provided as a software package that enables easy entry of pertinent data, as well as automatic access to engineering design rules and various databases containing pertinent component attributes and their relationship information. As a software package, the condensing unit configurator quickly and seamlessly determines the configuration of the condensing unit14and provides comprehensive performance information. More specifically, the condensing unit configurator provides a rule-based algorithm that automates the engineering design and associated processes used to streamline the design process.

The configurator incorporates engineering design standards, Underwriter Laboratories (UL) safety regulations and pricing information to provide a quick response to customer needs. A user inputs system requirements including thermal performance, application type and optional components. The condensing unit configurator generates information including standard, off-the-shelf products, custom design solutions, engineering drawings, thermal performance information, bill of material (BOM) identifying key components and pricing information.

The elements of the condensing unit configurator include component databases, engineering rules, design processes and pricing algorithms. Other elements include physical and electrical component relationships and thermodynamic algorithms. The configurator uses two component categories to configure valid condensing unit assemblies. A major components category is used to build the thermal capacity module of the condensing unit. The components in the major components category include compressors, heat exchangers, air flow devices (e.g., fan motor and fan blade) and mounting chassis. An optional components category does not effect thermal performance, but is used for other functions of the condensing unit. The components in the optional components category include controls, pressure vessels, valves, fittings, electrical boxes and the like.

Referring now toFIG. 2, a flowchart provides a general outline of the condensing unit configurator according to the present invention.FIGS. 3 through 15provide software screen-shots illustrating particular steps of the configurator. The condensing unit configurator provides a user with three starting paths to initiate the configuration process: application requirements, condensing unit model number and compressor model.

Using the application requirements path, the user enters the capacity (Btu/hour or horsepower), electrical parameters (e.g., volts, frequency, phase), refrigerant type and application type (e.g., high, medium and low temperature installation). Using the condensing unit model number path, the user inputs a known, standard off-the-shelf unit. The configurator assists the user in modifying the standard unit by selecting optional components (i.e., custom design). Using the compressor model path, the user inputs a specific compressor model, its electrical parameters, refrigerant type and application type.

The configurator lists condensing units that feature the selected compressor model. In step100, the user selects between the application requirements path, the condensing unit model number path or the compressor model path (seeFIG. 3). If the user selects the application requirements path the configurator continues in step102. If the user selects the condensing unit model number path, the configurator continues in step104and if the user selects the compressor model path, the configurator continues in step106.

In step102, the user inputs the application parameters. The application parameters include design criteria, mode and application type. More specifically, the design criteria include refrigerant type, application range, evaporator temperature, normal ambient temperature, maximum ambient temperature and electrical information (e.g., frequency, phase and voltage). The application types indicate the particular type of fixture (e.g., walk-in, reach-in, environmental/medical, industrial, other or unknown). The key application parameter is the mode, which includes either capacity or horsepower.FIG. 4illustrates an application parameter input screen for the capacity mode andFIG. 5illustrates an application parameter input screen for the horsepower mode.

In step108, the configurator determines condensing units based on the application parameters and provides an output screen based on the particular mode (seeFIG. 6). The output screen shows the basic condensing unit configurations (i.e., without optional components) and provides associated information such as physical dimensions, thermal performance, electrical information and pricing information.

In step104, the user inputs known, relevant condensing unit information (seeFIG. 7). This information includes condensing unit model number, design parameters, electrical parameters and application type. More specifically, the design parameters include refrigerant type, application range and maximum ambient temperature. The electrical parameters include frequency, phase and voltage. The application types indicate the particular type of fixture (e.g., walk-in, reach-in, environmental/medical, industrial, other or unknown).

The user can immediately select a condensing unit model number. However, if the user is unsure of the exact model number, the condensing unit model number list narrows based on the condensing unit information input. In other words, the condensing unit model number list gradually becomes shorter as information such as refrigerant type, application range, voltage, application type and the like are input. In step110, the user selects the exact condensing unit desired. As shown inFIG. 8, the configurator summarizes the specific condensing unit information for the chosen condensing unit. The configurator also summarizes relevant condensing unit information as seen inFIG. 9. This information includes, design information such as normal air temperature, evaporator temperature, maximum air temperature, unit capacity, dimensions and electrical parameters. The base price (without optional components) of the condensing unit is also provided.

In step106, the user inputs known, relevant compressor information (seeFIG. 10). This information includes compressor model number, design conditions, electrical parameters and application type. More specifically, the design conditions include refrigerant type, application range, maximum air temperature, evaporator temperature and normal air temperature. The electrical parameters include frequency, phase, voltage and electrical code. The application types indicate the particular type of fixture (e.g., walk-in, reach-in, environmental/medical, industrial, other or unknown).

The user can immediately select a compressor model number. However, if the user is unsure of the exact model number, the compressor model number list narrows based on the compressor information input. In other words, the compressor model number list gradually becomes shorter as information such as refrigerant type, application range, voltage, application type and the like are input. In step112, the user selects the exact compressor desired. As shown inFIG. 11, the configurator summarizes the information for the chosen compressor. As seen inFIG. 12, the configurator lists the specific condensing units available for use with the user specified compressor. The information for the possible condensing units is summarized. This information includes, design information such as normal air temperature, evaporator temperature, maximum air temperature, unit capacity, dimensions and electrical parameters. The base price (without optional components) of the condensing unit is also provided.

Regardless of the path used to determine the base condensing unit (i.e., major components category), the configurator continues in steps114,116and118to determine the desired options (i.e., optional components category) for air-cooled condensing units. In step114, the user selects desired accessories from an accessory menu (seeFIG. 13). The accessories include an accumulator, a filter drier, a moisture indicator/sight glass, a shrader in the compressor's process connector, a discharge line thermostat, a crankcase heater, a monel discharge tube, a conduit, a service cord, a base mounted electrical box, condenser end covers, a fan guard and a defrost timer. The user selects a check box next to the desired accessory. Only valid accessory choices are displayed. Those accessories that are unavailable for the particular model type are grayed and not selectable by the user. The configurator also checks and indicates agency approval for the particular condensing unit and optional components selected, including UL/CSA, UR or none.

In step116, the user indicates desired high and low side options (seeFIG. 14). The high-side options include a receiver, a flare connection, a liquid base valve (shut-off valve) or a braze directly into condenser. Other options include connection size, connection type (flare or sweat), pumpdown capacity and low ambient (fan cycling, head pressure) controls. The low-side options include a suction valve, braze directly to compressor, connection type (flare or sweat) and connection size.

In step118, the user indicates desired pressure control options (seeFIG. 15). The pressure control options include fixed-set point type control and adjustable set-point type control. The fixed set-point type control includes high pressure and the adjustable set-point type controls include low pressure, high pressure and dual pressure. The availability of the pressure control options depend on the particular condensing unit selected. The configurator checks the electrical load handling capability of the pressure control against that of the condensing unit in addition to the maximum pressure requirements of the condensing unit's refrigerant to select the appropriate pressure control part number.

Having selected the desired options in steps114,116and118configuration of the condensing unit is complete. The condensing unit configurator of the present invention provides additional business and customer-service information capabilities, such as developing reports (step120), which will be discussed more fully below.

Referring now toFIG. 16 through 26, the various business and customer-service capabilities will be described in detail. With particular reference toFIG. 16, a user can quickly retrieve or input customer details including name, address, principal contact, shipping address and the like. Customer details are stored in a database that enables searching for an existing customer or adding new customers. The configurator draws data from a central computer system and transforms it into a compatible database on a periodic basis so that data is current. The user selects the customer (by name) and the configurator fills all of the appropriate fields such address, customer contact, application engineer (supporting customer), etc., which automatically reduces the data entry time and human errors. This information is then brought into the next screen shown inFIG. 17.FIG. 17shows customer details and ordering information. The customer details (address, contact, etc.) are filled in and the order number and quantity, etc., are entered by the user in the appropriate fields.

Referring now toFIG. 18, key information regarding the condensing unit is displayed. The user can enter any special customer requests such as shipment of samples before delivery of actual units. A search of standard off-the-shelf units is also available, which may be close to the configured condensing unit. The configurator provides a graphical comparison of the standard condensing unit and the configured condensing unit. This is accomplished by choosing the Like BOM (Bill-of-Material) button. An example, of the graphical comparison is shown inFIG. 19.

FIG. 19illustrates the graphical comparison showing the optional components of the standard off-the-shelf and configured condensing unit. This is provided for informational purposes so that the customer may decide to choose the standard unit with shorter delivery time and possibly with a lower cost instead of the configured condensing unit. The first row labeled ‘Selection’ shows the optional components of the configured condensing unit. The row entitled ‘LIKE208’ shows the optional components of the standard unit having BOM number208. The next two rows show the components that must be added or deleted relative to the standard BOM. A summary of the added/deleted components is provided in the last row labeled ‘LIKE BOM(s)’.

Referring now toFIG. 20, the configurator enables viewing and printing of reports. The report formats include HTML and MS Word. The user can view/print a consolidated report (e.g., Cover Letter (seeFIG. 21), Quote Sheet (seeFIG. 22), Design Quote Team (DQT) Form (seeFIG. 23) and BOM Summary (seeFIG. 24)) by choosing the All Reports button. Reports can be viewed/printed individually by choosing the relevant button. The printing function is available when the report is under view.

Thermal performance information is generated by choosing the Unit Performance View button. Thermodynamic algorithms are integrated in the configurator to generate thermal performance based on the configured components of the condensing unit. Default performance data is provided for standard ambient air conditions (e.g., 70-100° F., 75-105° F., 80-110° F., 85-115° F., 90° F.-120° F., 95-125° F. or 100-130° F.) (seeFIG. 26). The user may generate performance for other selectable ambient air conditions. Generic drawings showing the layout of the condensing unit are accessed by choosing Unit Drawing|View button (seeFIG. 25).

The configurator also enables saving of the condensing unit configuration for future retrieval and editing. This is accessed by choosing the Commit Changes to Database button. This function saves data in a database on a network. The Save button saves data to the local hard drive of the user's computer. The objective of saving to local hard drive is for cases where the configurations are not finalized and have not been submitted to the customer.