5. CLAIMS

1. A hybrid independent tandem heat exchanger system (300), wherein the system comprises of: a. at least 2 heat exchangers (302) for the required heat transfer; b. at least 2 expansion (305) and non-return valves (304) for the flow of refrigerant through the circuit; c. a plurality of solenoid valves (306) for the control of refrigerant flow; d. cooling units (308) for evaporation of liquid/refrigerant; Characterized in that: e. at least two compressors (310) fluidly coupled to all the other components within the proposed heat exchanger system; f. a pressure equalization line fluidly coupling the first compressor and the second compressor; g. an oil equalization line / oil separation line of the individual compressors; and h. the proposed circuit arrangement enables to use the heat exchanger system as either independent or tandem system for increased heat transfer using the complete area of the second heat exchanger at lower loads.

2. The system (300) as claimed in claim 1, wherein the compressors (310) are used in the refrigeration circuit and the said compressors (310) are independent in their nature of operation and are designed/ modified to work as a tandem-independent system.

3. The system (300) as claimed in claim 1, wherein the solenoid valves (306) are four in number coupled to the compressors (310) and the said valves are operated based on the ON/OFF status of the compressors (310).

4. The system (300) as claimed in claim 1, wherein the solenoid valves (306) control and restrict the flow of refrigerant, the said solenoid valves 1 and 2 (307) are in OFF state in normal cycle of operation making the system (300) work independently.

5. The system (300) as claimed in claim 1, wherein the solenoid valves 3 or 4 (309) turns OFF respective to the compressor 1 or 2 (310), whichever is turned OFF due to the condition of lower loads on the system (300).

6. The system (300) as claimed in claim 1, wherein the non-return valves (305) positioned in the discharge line of each compressor (310) would help in avoiding the flow of refrigerant to the non-working compressor at the condition of lower loads.

7. The system (300) as claimed in claim 1, wherein the proposed Heat exchanger circuit (300) is operated for using the conventional independent heat exchanger system as a tandem at the lower loads as well as independent heat exchanger system normally.

6. DATE AND SIGNATURE Dated this 19th of May, 2020 Signature (Mr. Anugu Vijaya Bhaskar Reddy) IN/PA 2420 Agent for the Applicant

DESC:FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

1. TITLE OF THE INVENTION
HYBRID INDEPENDENT TANDEM HEAT EXCHANGER SYSTEM

2. APPLICANT(S)
(a) NAME: WERNER FINLEY PRIVATE LIMITED
(b) NATIONALITY: INDIAN
(c) ADDRESS: No. A-105, 3RD MAIN, 2ND STAGE,
PEENYA INDUSTRIAL AREA, BENGALURU - 560058,
KARNATAKA, INDIA

3. PREAMBLE TO THE DESCRIPTION
COMPLETE
The following specification particularly describes the invention and the manner in which it is to be performed.
4. DESCRIPTION

Field of the Invention

Embodiments of the invention generally relate to heating, ventilation, air conditioning & Refrigeration ("HVAC & R") systems. Specifically, embodiments of the invention relate to hybrid independent tandem system with multiple compressors.

Background of the Invention

Refrigerant cycles are utilized in applications to change the temperature and humidity or otherwise condition the environment or a process. In a standard refrigerant system, a compressor delivers a compressed refrigerant to an outdoor heat exchanger, known as a condenser. From the condenser, the refrigerant passes through an expansion device, and then to an indoor heat exchanger, known as an evaporator. In the evaporator, temperature of air/ water/ any medium passed through the coil is lowered. From the evaporator, the refrigerant returns to the compressor.
Compressor systems are commonly utilized in HVAC applications. To improve efficiency of HVAC system, multiple compressors are often utilized. Such Multiple compressors allow the compressor to turn on/off, and thus the capacity to be modulated according to an HVAC load in an enclosed space. Oftentimes, an inability of a multiple compressors in tandem circuit introduces further inefficiencies to the HVAC system during periods of maintenance.

FIG.1 illustrates a conventional refrigeration system normally, are multiplied individually and proposed as single units for the specified requirement, which has its own advantages of 50% or more redundancy & individual serviceability of components without affecting the second circuit in the system. Both the circuit are independent and are used as individual number of units based on the required output. The system comprises of heat exchanger (132), expansion valve, cooling unit (138) and compressor (140) for delivering the required temperature in the conventional HVAC/refrigeration system.

FIG. 2 illustrates a tandem circuit with two compressors (250) working in tandem with each other. The single refrigeration system is modified using two compressors (250) working in parallel with a common heat exchanger. The advantage of this was higher heat transfer efficiency at lower loads below 50%, due to the increase in heat exchange surface area i.e., the heat exchanger (242) which is designed for two compressors (250) was being used by single compressor at lower loads.

US10465937B2 discloses a hybrid tandem compressor system with a variable-speed compressor and a fixed-speed compressor. A control unit is operatively coupled to the variable-speed compressor and is operatively coupled to the fixed-speed compressor. A sensor is operatively coupled to the control unit and disposed in an enclosed space. The sensor measures at least one of a temperature and a relative humidity of the enclosed space and determines an HVAC load of the enclosed space. Responsive to a determination of the HVAC load, the control unit directs operation of the variable-speed compressor and the fixed-speed compressor. However the system works collectively and needs to be shut down whenever there is a need for maintenance.

Another patent US10168082B2 discloses a slide plate and slide rail assembly that can allow compressors to be slidably removed or adjusted to allow for easy repair or servicing. Instead of disassembling an entire compressor unit when repairs are needed on it or on neighboring components, the compressor unit can be quickly moved. Dual slide rail and slide plate configurations are described as well. However the proposed assembly for operation can be achieved when used two compressors and both the compressors are dependent and so independent system of operation and tandem system is not possible simultaneously.

Tandem compressors are normally connected together via common suction and common discharge manifolds. A tandem configuration reduces operating costs through greater capacity control and lower power consumption. Staging the operating sequence of the compressors allows system capacity to match system load. The unloading of conventional fixed speed compressors imposes a serious efficiency penalty at part load or low load conditions. But in a tandem installation, an individual compressor can be switched off while the other compressor continues to run, delivering full capacity and full load efficiency.

The limitations of existing tandem system are that the compressors, heat exchangers and accessories of individual system are not serviceable separately.

Thus, there is a need to develop tandem compressors in which the individual compressors and heat exchangers can be serviced separately along with the tandem and independent system of operations based on the active loads.

Brief Summary of the Invention

The following summary provides an introduction to selected concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. Further, while certain disadvantages of other technologies may be noted or discussed herein, the claimed subject matter is not intended to be limited to implementations that may solve or address any or all of the disadvantages of those other technologies. The sole purpose of this summary is to present some concepts of the claimed subject matter in a simplified form as a prelude to the more detailed description that is presented below.

It is an object of the present invention to increase heat transfer area while retaining the individuality of heat exchanger systems.

According to an aspect of the present invention, the proposed hybrid independent tandem heat exchanger system comprises of at least 2 heat exchangers for the required heat transfer, at least 2 expansion and non-return valves for the flow of refrigerant through the circuit, a plurality of solenoid valves for the control of refrigerant flow, cooling units for condensation of liquid/refrigerant.

In accordance with the aspect of the present invention, the compressors are characterized to fluidly couple to all the other components within the proposed heat exchanger system. The system comprises of a pressure equalization line fluidly coupling the first compressor and the second compressor, an oil equalization line / oil separation line of the individual compressors.

In accordance with the aspect of the present invention, the proposed circuit arrangement enables to use the heat exchanger system as either independent or tandem system for increased heat transfer using the complete area of the second heat exchanger at lower loads.

In accordance with the aspect of the present invention, the solenoid valves, along with non-return and pressure equalizing line aid in the making the system to work as either independent system or tandem system.

In accordance with the other aspect of the present invention, the system can also work with more than two compressors with the corresponding changes in the circuit and fulfils the object of the present invention to provide hybrid independent tandem system in which each independent unit can be serviced without affecting the other unit.

Other features of the embodiments will be apparent from the accompanying drawings and the detailed description that follows.

Brief Description of the Drawings

Example embodiments of the present invention are illustrated by accompanying drawings, wherein:

FIG.1 illustrates a conventional multiple circuit refrigeration system;

FIG. 2 illustrates a tandem circuit with two compressors working in tandem with each other;

FIG. 3 illustrates a hybrid tandem independent system circuit, according to one embodiment of the invention;

FIG. 4 illustrates a hybrid tandem independent system with the detailed flow lines of the fluid/refrigerant according to one embodiment of the invention.

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present invention in any way.

Detailed Description of the Invention

It is to be understood that the present disclosure is not limited in its application to the details of composition set forth in the following description. The present disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

The use of “including”, “comprising” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

Refrigerant cycles are utilized in applications to change the temperature and humidity or otherwise condition the environment. In a standard refrigerant system, a compressor delivers a compressed refrigerant to an outdoor heat exchanger, known as a condenser. From the condenser, the refrigerant passes through an expansion device, and then to an indoor heat exchanger, known as an evaporator. In the evaporator, temperature of air/ water/ any medium passed through the coil is lowered. From the evaporator, the refrigerant returns to the compressor. This cycle continues and the required temperature is achieved and maintained.

FIG. 3 illustrates a hybrid tandem independent system circuit, according to an exemplary embodiment of the present invention. As shown in FIG. 3, the proposed hybrid independent tandem heat exchanger system (300) comprises of at least 2 heat exchangers (302) for the required heat transfer, at least 2 expansion (305) and non-return valves (304) for the flow of refrigerant through the circuit, a plurality of solenoid valves (306) for the control of refrigerant flow, cooling units (308) for Cooling of liquid/any media, at least two compressors (310) fluidly coupled to all the other components within the proposed heat exchanger system, a pressure equalization line fluidly coupling the first compressor and the second compressor, an oil equalization line / oil separation line of the individual compressors.

In accordance with the exemplary embodiment of the present invention, the proposed circuit arrangement (300) enables to use the heat exchanger system as either independent or tandem system for increased heat transfer using half the area of the second heat exchanger (302) at lower loads. The hybrid tandem independent system (300) has two compressors (310) to deliver the compressed refrigerant to the required heat exchanger (302). The system (300) may have more than two compressors as well.

In accordance with the exemplary embodiment of the present invention, the two compressors (310) work independently to deliver the compressed refrigerant to the heat exchanger (302) in the hybrid tandem independent system circuit.

In accordance with the exemplary embodiment of the present invention, the two compressors work as tandem / independent in the hybrid tandem independent system circuit.

In accordance with the exemplary embodiment of the present invention, the solenoid valves (306), namely solenoid valve 1, solenoid valve 2 (307), solenoid valve 3 and solenoid valve 4 (309) along with non-return valve 1 and non-return valve 2 (304) and pressure equalizing line aid in the making the system (300) to work as either independent system or tandem system.

In accordance with the exemplary embodiment of the present invention, the solenoid valves (306) (four in number) are coupled to the compressors (310) and the said valves are operated based on the ON/OFF status of the compressors (310).

In accordance with the exemplary embodiment of the present invention, the present hybrid independent tandem system (300) allows the servicing of individual heat exchangers (302).

In accordance with the exemplary embodiment of the present invention, the present hybrid independent tandem system (300) provides more heat exchanger area at lower loads.

FIG. 4 illustrates the hybrid tandem independent system with the detailed flow lines of the fluid/refrigerant according to the exemplary embodiment of the present invention. As shown in FIG.4, the compressors (410) in the circuit are fluidly coupled to each component in the system and configured to operate based on the active loads on the system (higher loads/lower loads) and the said compressors (410) are connected to the solenoid valves. The solenoid valves are operated based on the operation of the compressors ON/OFF status. In normal cycle of operation, the solenoid valve 1 and solenoid valve 2 are in OFF position making the system (400) to work as two independent HVAC systems.

In accordance with the exemplary embodiment of the present invention, the system may be in working condition while the second system can undergo for maintenance works. When the solenoid valve 1 and solenoid valve 2 are in OFF position, there is no inter-relationship between the two systems.

When the system load is low & either of the compressor 1 or compressor 2 (410) is OFF, solenoid valve 1 & solenoid valve 2 turns ON at the same time. At this time, the solenoid valve 3 or solenoid valve 4 turns OFF respective to the inactive compressor 1 or 2 (410) respectively. The non-return valve (NRV 1) in the discharge line of each compressor (410) avoids the flow of refrigerant to the “OFF” compressor (Non-working) respectively. This arrangement further helps the independent heat exchanger system to function as a tandem heat exchanger system at the required lower loads.

It will be recognized that the above described subject matter may be embodied in other specific forms without departing from the spirit or essential characteristics of the disclosure. Thus, it is understood that, the subject matter is not to be limited by the foregoing illustrative details, but it is rather to be defined by the appended claims.

While specific embodiments of the invention have been shown and described in detail to illustrate the novel and inventive features of the invention, it is understood that the invention may be embodied otherwise without departing from such principles.
,CLAIMS:5. CLAIMS
I/We CLAIM
1. A hybrid independent tandem heat exchanger system (300), wherein the system comprises of:
a. at least 2 heat exchangers (302) for the required heat transfer;
b. at least 2 expansion (305) and non-return valves (304) for the flow of refrigerant through the circuit;
c. a plurality of solenoid valves (306) for the control of refrigerant flow;
d. cooling units (308) for evaporation of liquid/refrigerant;
Characterized in that:
e. at least two compressors (310) fluidly coupled to all the other components within the proposed heat exchanger system;
f. a pressure equalization line fluidly coupling the first compressor and the second compressor;
g. an oil equalization line / oil separation line of the individual compressors; and
h. the proposed circuit arrangement enables to use the heat exchanger system as either independent or tandem system for increased heat transfer using the complete area of the second heat exchanger at lower loads.

2. The system (300) as claimed in claim 1, wherein the compressors (310) are used in the refrigeration circuit and the said compressors (310) are independent in their nature of operation and are designed/ modified to work as a tandem-independent system.

3. The system (300) as claimed in claim 1, wherein the solenoid valves (306) are four in number coupled to the compressors (310) and the said valves are operated based on the ON/OFF status of the compressors (310).

4. The system (300) as claimed in claim 1, wherein the solenoid valves (306) control and restrict the flow of refrigerant, the said solenoid valves 1 and 2 (307) are in OFF state in normal cycle of operation making the system (300) work independently.

5. The system (300) as claimed in claim 1, wherein the solenoid valves 3 or 4 (309) turns OFF respective to the compressor 1 or 2 (310), whichever is turned OFF due to the condition of lower loads on the system (300).

6. The system (300) as claimed in claim 1, wherein the non-return valves (305) positioned in the discharge line of each compressor (310) would help in avoiding the flow of refrigerant to the non-working compressor at the condition of lower loads.

7. The system (300) as claimed in claim 1, wherein the proposed Heat exchanger circuit (300) is operated for using the conventional independent heat exchanger system as a tandem at the lower loads as well as independent heat exchanger system normally.

6. DATE AND SIGNATURE

Dated this 19th of May, 2020
Signature

(Mr. Anugu Vijaya Bhaskar Reddy)
IN/PA 2420
Agent for the Applicant