The disclosure herein relates generally to a heat recovery system, such as for example, a refrigerant system that provides cooling and heating. In particular the disclosure herein relates to a heat recovery system that includes a liquid separator, which allows for less refrigerant charge to be needed for operation of the heat recovery system relative to certain serial and parallel flow systems.
Heat recovery systems are known, which employ a heat recovery exchanger, for example to heat water for various uses, including residential or commercial use. The refrigerant charge used in heat recovery systems can be relatively high. For example, depending on the amount of capacity used by the heat recovery exchanger, a high amount of liquid refrigerant can be exited from the heat recovery heat exchanger. The condenser may then fill up with the high amount of liquid, where a liquid receiver is in fluid communication with the liquid outlet of the condenser, for example where the liquid receiver is in fluid communication with the condenser intermediate of the condensing portion and the sub-cooler portion. A relatively large receiver is employed to handle the refrigerant charge.
The disclosure herein relates generally to a heat recovery system, such as for example, a refrigerant system that provides cooling and heating. In particular the disclosure herein relates to a heat recovery system that includes a liquid separator, which allows for less refrigerant charge to be needed for operation of the heat recovery system relative to for example certain serial and parallel flow systems.
Heat recovery exchangers are useful in heat recovery systems, but in some circumstances can require a significant refrigerant charge, because the outlet of the heat recovery exchanger can contain a substantial amount of liquid refrigerant that flows to the condenser. The liquid rate into the condenser increases and, when the inlet of condenser is with high liquid rate, the refrigerant amount in the condenser fills with liquid, and is much higher than when the inlet of the condenser receives refrigerant vapor only.
Using a liquid separator in the heat recovery systems herein to separate the liquid and vapor from the fluid exiting the heat recovery exchanger can ensure that the inlet of the condenser coil is sourced with vapor and minimizes liquid entering the condenser coil, if at all, such as during normal operating modes (e.g. cooling and/or heat recovery modes).
In an embodiment, the liquid separator does not receive liquid refrigerant from the condenser coil, such as in a regular operating mode (e.g. cooling and/or heating mode). The use of the liquid separator and its arrangement within the fluid circuit can thereby reduce the operating refrigerant charge needed for the system.
In an embodiment, liquid flows out of the liquid separator and through a valve, then into another portion of the fluid circuit. For example, the liquid flows out of the liquid separator to a liquid portion of the condenser coil, such as for example a sub-cooling section, while vapor flows out of the liquid separator and into the condenser coil at a vapor inlet to be condensed to liquid by the condenser coil and then flow into the liquid portion. The liquid in other examples can flow to the expansion device and not flow to the condenser, e.g. liquid portion or sub-cooling section.
Heat recovery systems herein can include any suitable fluid system which can recover heat generated and/or rejected by the system to be used for another purpose. Examples include but are not limited to fluid chillers, such as for example water chillers, and also heat pumps, which may include heat recovery and/or hot water supply. In an embodiment, the charge of fluid is one or more refrigerants or a refrigerant mixture, which may include a lubricant such as for example oil, and potentially other additives.
The heat recovery systems herein, by use of the liquid separator, can provide both cooling and heating (e.g. heat recovery) at a relatively large capacity but with relatively lower refrigerant charge requirements. This can result in being able to employ a relatively smaller receiver, as the receiver acts as a liquid separator.
The heat recovery design herein can be useful in the design of for example a fluid chiller, such as for example an air cooled chiller with heat recovery options having less refrigerant charge added and high reliability. Use of the liquid separator reduces and/or avoids liquid from going into the inlet of the condenser coil, requiring less charge.
In an embodiment, a flow control device can control the heat recovery and/or cooling capacity of the heat recovery system.
In an embodiment, a heat recovery system includes a compressor, a heat recovery exchanger in fluid communication with the compressor, a liquid separator in fluid communication with the heat recovery exchanger. The liquid separator includes a vapor outlet and a liquid outlet. The heat recovery system includes a condenser having an inlet in fluid communication with the vapor outlet of the liquid separator. The liquid outlet of the liquid separator is in fluid communication with a component of the system other than the inlet of the condenser, where liquid from the liquid outlet flows downstream of the condenser. The heat recovery system includes an expansion device in fluid communication with the condenser and the component, and an evaporator in fluid communication with the expansion device and the compressor.
In an embodiment, the heat recovery system includes a flow control device between the vapor outlet of the liquid separator and the inlet of the condenser, the flow control device is in fluid communication with the vapor outlet of the liquid separator and in fluid communication with the inlet of the condenser.
In an embodiment, the heat recovery system includes a flow control device between the liquid separator and the component, the flow control device is in fluid communication with the liquid outlet of the liquid separator and in fluid communication with an inlet of the component.
In an embodiment, one or more of the flow control devices herein are one of a solenoid valve, multiple solenoid valves in parallel flow, and a graduating device.
In an embodiment, the heat recovery exchanger is in fluid communication with the condenser during cooling mode and/or heat recover mode only by way of the vapor outlet of the liquid separator.
In an embodiment, the inlet of the condenser is not in fluid communication with a liquid line of the system.
In an embodiment, the condenser includes a condensing section and a sub cooling section. The inlet of the condenser is to the condensing section, and the sub cooling section is the component in fluid communication with the liquid outlet of the liquid separator.
In an embodiment, a method of fluid flow through a fluid circuit during a cooling mode and/or a heat recovery mode includes: compressing a working fluid into a vapor; directing the working fluid from the compressor to a heat recovery exchanger in fluid communication with the compressor; recovering heat from the working fluid passing through the heat recovery exchanger, the working fluid including some liquid as a result of the step of recovering heat; directing the working fluid to a liquid separator in fluid communication with the heat recovery exchanger, the liquid separator including a vapor outlet and a liquid outlet; separating vapor from the liquid of the working fluid; directing the separated vapor into an inlet of a condenser, which is in fluid communication with the vapor outlet of the liquid separator; directing the liquid from the working fluid into an inlet of a component, which is in fluid communication with the liquid outlet of the liquid separator; directing the vapor through the condenser to condense the vapor into liquid, and directing the liquid condensed by the condenser and the liquid from the component to an expansion device to expand the liquid, the expansion device is in fluid communication with the condenser; directing the expanded liquid to an evaporator to evaporate the expanded liquid, the evaporator is in fluid communication with the expansion device; and directing the evaporated fluid back to the compressor.
In an embodiment, the method includes controlling flow to the inlet of the condenser by using a flow control device between the liquid separator and the condenser, the flow control device is in fluid communication with the vapor outlet of the liquid separator and in fluid communication with the inlet of the condenser.
In an embodiment, the method includes controlling flow to the inlet of the component by using a flow control device between the liquid separator and the component, the flow control device is in fluid communication with the liquid outlet of the liquid separator and in fluid communication with the inlet of the component. In embodiment, the flow control device between the liquid separator and the component is to let liquid in the liquid separator flow out and stop vapor flow until for example, there is no liquid in the separator.
In an embodiment, the step of directing the separated vapor into the inlet of the condenser includes fluid communication of the heat recovery exchanger with the condenser only by way of the vapor outlet of the liquid separator.
In an embodiment, the step of directing the separated vapor into the inlet of the condenser includes the inlet of the condenser not being in fluid communication with a liquid line of the fluid circuit.
In an embodiment, the condenser includes a condensing section and a sub-cooling section. The inlet of the condenser is to the condensing section, and the sub-cooling section is the component in fluid communication with the liquid outlet of the liquid separator.
These and other features, aspects, and advantages of the heat recovery system and methods of use thereof will become better understood when the following detailed description is read with reference to the accompanying drawing, wherein:
While the above figures set forth embodiments of the heat recovery system and methods of use thereof, other embodiments are also contemplated, as noted in the following descriptions. In all cases, this disclosure presents illustrated embodiments of the heat recovery system and methods of use thereof by way of representation but not limitation. Numerous other modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of the heat recovery system and methods of use thereof described herein.
The disclosure herein relates generally to a heat recovery system, such as for example, a refrigerant system that provides cooling and heating. In particular the disclosure herein relates to a heat recovery system that includes a liquid separator, which allows for less refrigerant charge to be needed for operation of the system relative to for example certain and parallel flow systems.
In the example shown, the heat recovery system is an air-cooled chiller with heat recovery capability. The heat recovery exchanger 10 is between the discharge of the compressor 1 and the condenser, e.g. the condensing section of the coil 3. This connection is called a serial design. In
The system of
Furthermore, serial connection designs need significantly more refrigerant charge. A reason is that refrigerant entering the condenser coil 3 is two phase (vapor and liquid) instead of superheated refrigerant vapor, since the refrigerant first passes through the heat recovery exchanger 10 and condenses before entering the condenser coil 3. This can result in more liquid charge in the condenser coil 3 and relative piping. Such a system may also employ additional devices to regulate water flow, and to limit heat exchange capacity, such as when a water temperature through the heat recovery exchanger is too low.
While the serial design of
In
In both of the serial design (
The design of
It will be appreciated that the liquid outlet of the liquid separator is in fluid communication with a component of the system other than the inlet of the condenser. In an embodiment, the heat recovery system does not include a sub-cooling section 5. In
In an embodiment, the condenser 3 includes a condensing section in fluid communication with a sub cooling section. The inlet of the condenser is to the condensing section, and the sub cooling section is the component in fluid communication with the liquid outlet of the liquid separator. This configuration is shown in
As shown in
In some designs, pressure regulating valve or valves 7 provide such functions. For example, the valve 7 is a check, which ensures refrigerant flow out of the condenser 3. It will be appreciated that the valve 7 may be changed to a regulating valve with variable flow, so that the flow rate through the condenser 3 can be changed, and so as to change the heat transfer through the condenser 3. The less flow through the condenser, then the more flow through valve 9, which can in some circumstances result in more refrigerant condensing in the heat recovery exchanger 10 providing more heat recovery. It will be appreciated that a regulating valve may be used as the flow control device 4. Its function is the same as using a regulating valve as the valve 7. The differences potentially are size and cost.
With such a design as in
By adjusting pressure regulating valve and fan speed, different heat recovery capacity can be obtained. And the manufacturing cost may be close to a-serial type designs. It will be appreciated that the flow control device or valve 4 can be removed when there may be cost limitations, and where there may not be a need for high capacity heat recovery or where the ambient temperature is always high.
In an embodiment, of the control items 1 and 2 provide further explanation.
1. When there is cooling only, the flow control device 4, e.g. solenoid valve, is open. Refrigerant is discharged from compressor 1, to heat recovery exchanger 10, then to liquid separator 6, and then to the condensing section of the coil 3, then into the sub cooling section 5 of the coil, and then passing to the expansion device (e.g. valve), then into the evaporator 13 for cooling. Flow control device 9, e.g. solenoid valve, can be open to reduce the risk of oil logging in the liquid separator 6.
In an embodiment, it will be appreciated that the flow control device can also be one valve controlled by a liquid level in the liquid separator 6.
In an embodiment, the flow control device can be floating valve and built in the receiver.
2. If the flow control device 4 includes multiple valves, e.g. solenoid valves, that are paralleled, then different valve(s) can be opened to obtain get different heat recovery capacity. In an embodiment, the flow control device can be a controllable and/or graduated device that is not structured as multiple valves but provides capacity management. Some refrigerant passes heat recovery exchanger 10, and different levels of heating capacity, including relatively lower levels of heating capacity may be obtained. Fans 2 are adjusted by differential pressure.
Aspects: Any of aspects 1 to 8 may be combined with any of aspects 9 to 14.
Aspect 1. A heat recovery system, comprising:
Aspect 2. The heat recovery system of Aspect 1, further comprising a flow control device between the vapor outlet of the liquid separator and the inlet of the condenser, the flow control device is in fluid communication with the vapor outlet of the liquid separator and in fluid communication with the inlet of the condenser.
Aspect 3. The heat recovery system of Aspect 2, wherein the flow control device between the liquid separator and the condenser is one of a solenoid valve, multiple solenoid valves in parallel flow, and a graduating device.
Aspect 4. The heat recovery system of any one of Aspects 1 to 3, further comprising a flow control device between the liquid separator and the component, the flow control device is in fluid communication with the liquid outlet of the liquid separator and in fluid communication with an inlet of the component.
Aspect 5. The heat recovery system of Aspect 4, wherein the flow control device between the liquid separator and the component is one of a solenoid valve, multiple solenoid valves in parallel flow, and a graduating device.
Aspect 6. The heat recovery system of any one of Aspects 1 to 5, wherein the heat recovery exchanger is in fluid communication with the inlet of the condenser only by way of the vapor outlet of the liquid separator.
Aspect 7. The heat recovery system of any one of Aspects 1 to 6, wherein the inlet of the condenser is not in fluid communication with a liquid line of the system.
Aspect 8. The heat recovery system of any one of Aspects 1 to 7, wherein the condenser includes a condensing section and a sub cooling section, the inlet of the condenser is to the condensing section, and the sub-cooling section is the component in fluid communication with the liquid outlet of the liquid separator.
Aspect 9. A method of fluid flow through a fluid circuit during both a cooling mode and a heat recovery mode, comprising:
Aspect 10. The method of Aspect 9, further comprising controlling flow to the inlet of the condenser by using a flow control device between the liquid separator and the condenser, the flow control device is in fluid communication with the vapor outlet of the liquid separator and in fluid communication with the inlet of the condenser.
Aspect 11. The method of Aspect 9 or 10, further comprising controlling flow to the inlet of the component by using a flow control device between the liquid separator and the component, the flow control device is in fluid communication with the liquid outlet of the liquid separator and in fluid communication with the inlet of the component.
Aspect 12. The method of any one of Aspects 9 to 11, wherein the step of directing the separated vapor into the inlet of the condenser includes fluid communication of the heat recovery exchanger with the condenser only by way of the vapor outlet of the liquid separator.
Aspect 13. The method of any one of Aspects 9 to 12, wherein the step of directing the separated vapor into the inlet of the condenser includes the inlet of the condenser not being in fluid communication with a liquid line of the fluid circuit.
Aspect 14. The method of any one of Aspects 9 to 13, wherein the condenser includes a condensing section and a sub-cooling section, the inlet of the condenser is to the condensing section, and the sub-cooling section is the component in fluid communication with the liquid outlet of the liquid separator.
The terminology used in this specification is intended to describe particular embodiments and is not intended to be limiting. The terms “a,” “an,” and “the” include the plural forms as well, unless clearly indicated otherwise.
While the embodiments have been described in terms of various specific embodiments, those skilled in the art will recognize that the embodiments can be practiced with modification within the spirit and scope of the claims.
Filing Document | Filing Date | Country | Kind |
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PCT/CN2015/083065 | 7/1/2015 | WO | 00 |