1. A pressure swing adsorption (PSA) process, comprising using molecular sieves, and heating a pre-adsorption stream before the pre-adsorption stream is fed into the molecular sieves, wherein most of the thermal energy needed for said heating is provided by condensation of a post-adsorption stream coming from the molecular sieves by means of an equipment arrangement for heat exchange, said equipment arrangement comprising at least two vertical Shell and Tube type heat exchangers in parallel.
2. A PSA process according to claim 1, characterized in that a separation vessel is arranged downstream from said at least two vertical Shell and Tube type heat exchangers in parallel.
3. A PSA process according to claim 1, characterized in that said equipment arrangement for heat exchange uses thermal oil.
4. A PSA process according to claim 3, characterized in that said thermal oil, after condensing the post-adsorption stream, flows to a surge tank and is then used to heat the pre-adsorption stream.
5. A PSA process according to claim 1, characterized in that said equipment arrangement for heat exchange comprises a system using a surge tank after the arrangement of molecular sieves and before the heat exchangers.
6. A PSA process according to claim 5 characterized in that a flow rate control system is arranged downstream from said surge tank.
7. A pressure swing adsorption (PSA) system, comprising molecular sieves, and a heat exchange system, said heat exchange system comprising at least two vertical Shell and Tube type heat exchangers in parallel and arranged so that most of the thermal energy needed for heating of a pre-adsorption stream being fed to the molecular sieves is provided by condensation of a post-adsorption stream coming from the molecular sieves by means of said heat exchange system.
8. The pressure swing adsorption (PSA) system according to claim 7, characterized in that a separation vessel is arranged downstream from said at least two vertical Shell and Tube type heat exchangers in parallel.
9. The pressure swing adsorption (PSA) system according to claim 7, the heat exchange system using thermal oil.
10. The pressure swing adsorption (PSA) system according to claim 9, characterized in that said thermal oil, after condensing the post-adsorption stream, flows to a surge tank and is then used to heat the pre-adsorption stream.
11. The pressure swing adsorption (PSA) system according to claim 7, characterized by comprising a system using a surge tank after the arrangement of molecular sieves and before the heat exchange system.
12. The pressure swing adsorption (PSA) system according to claim 11, characterized in that a flow rate control system is arranged downstream from said surge tank.
13. A process of thermal energy recovery in a pressure swing adsorption (PSA) process, comprising the steps of feeding a pre-adsorption stream to molecular sieves, and recovering thermal energy generated from condensation of a post-adsorption stream coming from the molecular sieves, said thermal energy being used for heating the pre-adsorption stream by means of an equipment arrangement for heat exchange comprising at least two vertical Shell and Tube type heat exchangers in parallel, wherein most of the thermal energy needed for said heating is provided by the condensation of the post-adsorption stream.
14. A process of thermal energy recovery according to claim 13, characterized in that a separation vessel is arranged downstream from said at least two vertical Shell and Tube type heat exchangers in parallel.
15. A process of thermal energy recovery according to claim 13, characterized in that said equipment arrangement for heat exchange uses thermal oil.
16. A process of thermal energy recovery according to claim 15, characterized in that said thermal oil, after condensing the post-adsorption stream, flows to a surge tank and is then used to heat the pre-adsorption stream.
17. A process of thermal energy recovery according to claim 13, characterized in that said equipment arrangement for heat exchange comprises a system using a surge tank after the arrangement of molecular sieves and before the equipment arrangement for heat exchange.
18. A process of thermal energy recovery according to claim 17, characterized in that a flow rate control system is arranged downstream from said surge tank.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A system on chip (SOC) comprising:
a slave device:
a plurality of master devices configured to generate requests to demand services from the slave device;
an interconnect device coupled to the slave device and the master devices through respective channels, the interconnect device configured to perform an arbitrating operation on the requests; and
a plurality of service controllers configured to control request flows from the master devices adaptively depending on an operational environment change of the SOC.
2. The SOC of claim 1, further comprising:
a global controller configured to generate a global control signal based on at least one state signal, the global control signal indicating the operational environment change,
wherein the service controllers are configured to control the request flows based on the global signal.
3. The SOC of claim 2, wherein the slave device includes a memory controller and the master devices include a modem and a display controller, and
wherein the state signal includes at least one of:
a first state signal that is activated when an operational temperature of the memory controller becomes greater than a threshold temperature;
a second state signal that is activated when the modem is not serviced by the slave device for a threshold time; and
a third state signal that is activated when a data buffer rate of the display controller is lower than a threshold rate.
4. The SOC of claim 1, wherein each of the service controllers includes:
a monitor configured to generate a credit value by detecting a service requirement level of the corresponding master device in realtime; and
a control block configured to generate a local control signal to control the monitor based on the operational environment change and configured to generate a priority information signal for the request from the corresponding master device based on the credit value.
5. The SOC of claim 4, wherein the local control signal includes an overflow value, a unit increment value and a unit decrement value, and
wherein the monitor includes:
a first counter configured to generate a first event signal that is activated with a period corresponding to the overflow value;
a service detector configured to generate a second event signal based on channel signals transferred between the corresponding master device and the interconnect device, the second event signal being activated when the corresponding master device is serviced by the slave device; and
a second counter configured to increase the credit value by the unit increment value in response to each activation of the first event signal and configured to decrease the credit value by the unit decrement value in response to each activation of the second event signal.
6. The SOC of claim 5, wherein the control block is configured to change at least one of the overflow value, the unit increment value and the unit decrement value based on the operational environment change to control the request flow from the corresponding master device.
7. The SOC of claim 6, wherein the control block is configured to promote the request flow of the corresponding master device by decreasing the overflow value, increasing the unit increment value or decreasing the unit decrement value, and configured to demote the request flow from the corresponding master device by increasing the overflow value, decreasing the unit increment value or increasing the unit decrement value.
8. The SOC of claim 5, wherein the local control signal further includes a steal value that is provided when the operational environment change occurs, and second counter decreases the credit value by the steal value.
9. The SOC of claim 4, wherein at least one of the service controllers includes:
a limiter configured to block the request flow from the corresponding master device in response to a limit signal from the control block.
10. The SOC of claim 9, wherein the control block is configured to activate the limit signal when the credit value is smaller than a grant value, and configured to change the grant value based on the operational environment change to control the request flow from the corresponding master device.
11. The SOC of claim 9, wherein the limiter includes:
a synchronizer configured to generate a synchronized limit signal based on the limit signal;
a first logic gate configured to output a masked valid signal by performing a logic operation on the synchronized limit signal and a valid signal from the corresponding master device; and
a second logic gate configured to output a masked ready signal by performing a logic operation on the synchronized limit signal and a ready signal from the interconnect device.
12. The SOC of claim 4, wherein the control block is configured to set a plurality of operation modes by dividing ranges of the credit value and configured to change values of the local control signal based on the operation modes to control the request flow from the corresponding master device.
13. The SOC of claim 12, wherein the operation modes include:
a promotion mode corresponding to the credit value greater than a upper boundary value;
a default mode corresponding to the credit value smaller than the upper boundary value and greater than a lower boundary value; and
a demotion mode corresponding to the credit value smaller than the lower boundary value.
14. The SOC of claim 13, wherein the control block is configured to change the values of the local control signal based on the operation modes such that the corresponding master device is allowed to have a larger bandwidth in the promotion mode than the default mode and a larger bandwidth in the default mode than the demotion mode.
15. The SOC of claim 1, wherein the slave device includes:
a request queue configured to store the requests transferred from the master devices via the interconnect device; and
a scheduler configured to adjust a service order with respect to the stored requests based on priorities of the stored request.
16. The SOC of claim 15, wherein the master devices include at least one realtime master device, and the service controller corresponding to the realtime master device is configured to generate an urgent signal indicating that the realtime master device requires an urgent service from the slave device.
17. The SOC of claim 16, wherein the scheduler is configured to increase the priority of the stored requests from the realtime master device based on the urgent signal.
18. The SOC of claim 16, further comprising a transmission line that is point-to-point coupled between the slave device and the service controller corresponding to the realtime master device,
wherein the urgent signal is transferred via the signal line directly from the service controller corresponding to the realtime master device to the slave device.
19. The SOC of claim 15, wherein the master devices include at least one best effort master device, the slave device is configured to generate an external limit signal based on the operational environment change, and the service controller corresponding to the best effort master device is configured to block the request flow from the best effort master device in response to the external limit signal.
20. The SOC of claim 19, wherein the slave device is configured to activate the external limit signal when the number of the stored requests in the request queue is greater than a threshold number.
21. The SOC of claim 19, wherein the master devices further include at least one realtime master device, and the slave device is configured to activate the external limit signal in response to an urgent signal indicating that the realtime master device requires an urgent service from the slave device.
22. The SOC of claim 21, wherein the realtime master device includes a display controller and the best effort master device includes a processor.
23. The SOC of claim 19, further comprising a transmission line that is point-to-point coupled between the slave device and the service controller corresponding to the best effort device,
wherein the external limit signal is transferred via the signal line directly from the slave device to the service controller corresponding to the best effort master device.
24. A method of controlling a system on chip (SOC) including at least one slave device, a plurality of master devices configured to generate requests to demand services from the slave device, respectively, and an interconnect device coupled to the slave device and the master devices through respective channels, the method comprising:
generating at least one state signal indicating an operational state of at least one of the slave device and the master devices;
generating a global control signal based on the state signal, the global control signal indicating an operational environment change of the SOC; and
controlling request flows from the master devices adaptively depending on the global control signal.
25. A service controller configured to control a request flow from a master device to a slave device, the service controller comprising:
a monitor configured to generate a credit value by detecting a service requirement level of the master device in realtime; and
a control block configured to generate a local control signal to control the monitor based on an operational environment change and configured to generate a priority information signal for requests from the master device based on the credit value.
26. A system on chip (SOC) comprising:
a slave device:
first master and second master devices configured to generate requests to demand services from the slave device;
a sensor configured to detect whether an environmental condition of the SOC is in an abnormal state;
a service controller configured to increase a priority of the request from one of the first and second master devices, and decrease a priority of the request from the other one of the first and second master devices when the abnormal state has been detected; and
an interconnect device coupled to the slave device and the master devices through respective channels, the interconnect device configured to perform an arbitrating operation on the requests based on the corresponding priorities.
27. The SOC of claim 26, wherein the environmental condition is a temperature of the slave device and the abnormal state indicates that the temperature exceeds a threshold temperature.
28. The SOC of claim 26, wherein the environmental condition is latency of an exchange between the slave device and one of the master devices, and the abnormal state indicates the latency is greater than a threshold time.
29. The SOC of claim 26, wherein the environmental condition is a data buffer rate of a data buffer in one of the master devices, and the abnormal state indicates the data buffer rate is lower than a threshold rate.