CN105526670A - Apparatus and method for subcooling control based on superheat setpoint control - Google Patents

Abstract

The invention discloses an apparatus and a method for subcooling control based on superheat setpoint control. A system including a setpoint module, a summer, a control module, and an expansion valve module. The setpoint module is configured to indirectly control sub-cooling of a condenser by adjusting a superheat setpoint based on (i) a return air temperature setpoint or a supply air temperature setpoint, and (ii) an outdoor ambient temperature. The summer is configured to determine an error between the superheat setpoint and a superheat level of a compressor. The control module is configured to generate a control signal based on the error. The expansion valve module is configured to electronically control a state of an expansion valve based on the control signal.

Description

The equipment of the cold control of the mistake for controlling based on superheat setpoint and method

The cross reference of related application

Present disclosure is the U.S. Patent application the 14/078th submitted on November 13rd, 2013, the part continuation application of No. 734.This application claims the U.S. Provisional Application the 61/729th submitted on November 21st, 2012, the rights and interests of No. 037.Whole disclosures of above-mentioned application are merged into herein by reference.

Technical field

Present disclosure relates to cooling system, and relates more specifically to expansion valve control system.

Background technology

That this part provides not necessarily prior art, relevant to present disclosure background information.

In the application different in a large number that cooling system will be cooled at fluid, there is applicability.Fluid can be the gas of such as air or the liquid of such as water.Example application is the heating of space such as in office and data center for cooling people place, ventilation, air-conditioning (HVAC) system.Data center can refer to the room of the electronic installation set with such as computer server.

Figure 1 illustrates the air-conditioning 50 that can such as use between computer floor.Air-conditioning 50 comprises cooling circuit 51 and rack 52.Cooling circuit 51 is arranged in rack 52, and comprises evaporimeter 54, air moving device 56, compressor 58, condenser 60 and expansion valve 62.The closed-loop path connection that evaporimeter 54, compressor 58, condenser 60 and expansion valve 62 circulate to make cooling fluid (such as, phase change refrigerant).Evaporimeter 54 can comprise there is multiple coldplate (slab) V-arrangement coil pack to provide the cooling capacity of enhancing.Evaporimeter 54 receives cooling fluid and cools the air through the opening in evaporimeter 54.Air moving device 56 (such as, fan or squirrel cage blower) is from the entrance (not shown) draw air rack 52 and make it pass evaporimeter 54.Air through cooling to be derived and from the pumping chamber 64 rack 52 out from evaporimeter 54.

Compressor 58 makes cooling fluid cycle through condenser 60, expansion valve 62, evaporimeter 54 turn back to compressor 58.Compressor 58 can be such as scroll compressor.Scroll compressor can be constant speed, numeral or variable speed compressor.Scroll compressor generally includes two offset helical dishes.First helical disk is fixed disk or scroll portion.Second helical disk is moving scroll portion.Cooling fluid is received in the porch of scroll compressor, captured between offset helical dish, is compressed, and in center (or outlet) discharged to condenser 60.Condenser 60 can be the micro-channel condenser cooled the cooling fluid received from compressor 58.Expansion valve 62 can be electric expansion valve and can make to expand, such as, from liquid to gas from condenser 60 cooling fluid out.

The position (or percent travel of expansion valve) of variable expansion valve 62 can control the suction superheat value of compressor 58.The suction superheat value of compressor equals compressor inlet temperature and deducts the saturated inlet temperature of compressor.Compressor suction pressure can be used to determine the saturated inlet temperature of compressor.Compressor inlet temperature and compressor suction pressure can be determined based on the signal from the respective sensor be connected between evaporimeter 54 and compressor 58.Superheat value refers to that the temperature of the cooling fluid being in gaseous state is by the amount heated higher than the saturated inlet temperature of compressor.

Superheat value can be used adjust the position of (or adjustment) expansion valve 62.Can control passing ratio, integration, differential (PID) the control module position (or percent travel) that performs expansion valve 62.Pid control module controls superheat value to mate constant predetermined superheat setpoint.Which ensure that compressor stability and improve compressor efficiency.

Summary of the invention

This part provides the General Introduction of present disclosure, instead of its four corner or its institute characteristic comprehensively open.

Provide a kind of system, it comprises set point module, summer, control module and expansion valve module.Set point module is configured to regulate superheat setpoint indirectly to control the excessively cold of condenser by returning air themperature set point or supply air themperature set point and (ii) outdoor environment temperature based on (i).Summer is configured to the error determined between superheat setpoint and the superheat level of compressor.Control module is configured to generate control signal based on error.Expansion valve module is configured to the state based on control signal Electronic Control expansion valve.

On the other hand, provide a kind of method, it comprises: regulate superheat setpoint by returning air themperature set point or supply air themperature set point and (ii) outdoor environment temperature based on (i), indirectly control the excessively cold of condenser; Determine the error between superheat setpoint and the superheat level of compressor; Control signal is generated based on error; And based on the state of control signal Electronic Control expansion valve.

On the other hand, provide a kind of system, and this system comprises error module, this error module is configured to carry out integration to generate error signal to the difference between heat alarm and superheat setpoint, wherein the suction superheat value of heat alarm instruction compressor.Comparison module is configured to error signal and the first predetermined threshold to compare, to compare generation first comparison signal based on this.Zero crossing module is configured to the first count value and the second predetermined threshold be compared, to generate the second comparison signal.First count value compares based at least one between heat alarm with superheat setpoint to generate.Set point module is configured to regulate superheat setpoint based on the first comparison signal and the second comparison signal.

On the other hand, provide a kind of system, and this system comprises border counter, boundary module, set point module and control module.Border counter is configured to: when the heat alarm of compressor exceedes predetermined restriction, make the first count.Boundary module is configured to: the first count value and the first predetermined threshold are compared, to generate the first comparison signal.Set point module is configured to: regulate superheat setpoint based on the first comparison signal.Control module is configured to: based on the position of superheat setpoint variable expansion valve.

On the other hand, provide a kind of system, and this system comprises unstable module, discharge module and set point module.Unstable module is configured to: determine that the instability of compressor sucks overheated condition and whether exists, and generate unstable signal.Discharge module is configured to: the blowdown presssure of compressor and predetermined pressure are compared, to generate the first comparison signal.Set point module is configured to: regulate superheat setpoint based on unstable signal and the first comparison signal.

According to the description provided herein, other areas of applicability will become obvious.Description in content of the present invention and concrete example be only intended to for illustration of object, and be not intended to limit the scope of present disclosure.

Accompanying drawing explanation

Accompanying drawing described herein is not only the object of all possible implementation for illustration of selected implementation, and is not intended to limit the scope of present disclosure.

Fig. 1 is the perspective view of prior art air-conditioning;

Fig. 2 is the schematic diagram being combined with the multistage cooling system of cooling control module of an aspect according to present disclosure;

Fig. 3 is the functional block diagram of the superheat setpoint adjustment System of an aspect according to present disclosure;

Fig. 4 is the functional block diagram being combined with a part for the cooling control module of unstable module of Fig. 2 of an aspect according to present disclosure;

Fig. 5 is the logical flow chart of the superheat setpoint method of adjustment of the aspect illustrated according to present disclosure;

Fig. 6 is the functional block diagram of the superheat setpoint regulating system of an aspect according to present disclosure; And

Fig. 7 is the logical flow chart of the superheat setpoint control method of the aspect illustrated according to present disclosure.

Run through the several figure in accompanying drawing, corresponding Reference numeral represents corresponding part.

Detailed description of the invention

More fully sample implementation is described referring now to accompanying drawing.

Air-conditioning system can comprise condenser (or outdoor coil pipe used), expansion valve, evaporimeter (or indoor coil) and compressor.The position of expansion valve (or percent travel) can be adjusted to and to make the superheat value of compressor remain on predetermined (or adjustment) superheat setpoint place.Due to the change of the in-house operation condition of air-conditioning system, the instability of air-conditioning system can be caused to operate.Example disclosed in this article prevents instability condition from occurring, and if there is instability condition, then example makes air-conditioning system stabilisation.This instability prevents and stabilisation is by providing the adjustment of superheat setpoint and/or regulate.

The in-house operation condition of air-conditioning system may such as owing to changing requiring the change of temperature and/or dehumidifying setting.Operating condition changes, the loading of the loading (charge) of condenser and the relative size of capacity of evaporimeter and the cooling fluid in evaporimeter too low (be less than first predetermined load) or the cooling fluid in evaporimeter too high (be greater than second predetermined load) may cause unstable operation.The loading of cooling fluid can refer to amount or the quality of cooling fluid.Superheat value is kept, to avoid maximum discharge (output) pressure of compressor when can there is the cooling fluid of such as low loading in evaporimeter.When the blowdown presssure of compressor is greater than predetermined pressure, can close compressor.Keep superheat value may cause coming the excessively cold loss of condenser when there is the high cooling fluid loaded in evaporimeter.Cross cold loss and may cause unstable compressor operation.Unstable compressor operation may cause unstable air-conditioning system operation.

The superheat value that following public implementation comprises the compressor making to be under various operating condition is stablized.The cooling fluid that implementation comprises between management evaporimeter and condenser loads to obtain stable operation.This comprises and regulates superheat setpoint based on some parameter (such as, compressor suction pressure, compressor inlet temperature and compressor discharge pressure).Above-mentioned parameter depends on operating condition.Therefore, implementation provides the dynamic conditioning of superheat setpoint for expansion valve position control.Implementation makes the superheat setpoint of compressor to be stable into suitable set point, (or during operation of relevant air-conditioning system) can determine this suitable set point in real time.If unstable overheated condition detected, then perform superheat setpoint adjustment to reset superheat setpoint according to current setting, to make the loading rebalancing between evaporimeter and condenser, this stabilizes superheat value and Dynamic System.

Fig. 2 illustrates the schematic diagram of cooling system 100.Cooling system 100 can be frequency-conversion air-conditioning system, and comprises the upstream cooling class 102 with upstream (or first) cooling circuit 104 and downstream (or second) cooling class 106 with downstream cooling circuit 108.Cooling circuit 104,108 controls via cooling control module 109.Although show two cooling circuits, the cooling circuit of varying number can be comprised.Upstream cooling circuit 104 comprises the first evaporimeter 110, first expansion valve 112, first condenser 114, first compressor 116 and the second compressor 118.Downstream cooling circuit 108 comprises the second evaporimeter 120, second expansion valve 122, second condenser 124, the 3rd compressor 126 and the 4th compressor 128.Evaporimeter 110,120 has respective evaporator fan 130,132.Condenser 114,124 has respective condenser fan 134,136.

Cooling control module 109 can generate condenser fan signal COND1, COND2, evaporator fan signal EVAP1, EVAP2, expansion valve signal EXP1, EXP2, and signal compressor PWM1, PWM2, PUMP3, PUMP4, thus control fan 130,132,134,136, expansion valve 112,122 and compressor 116,118,126,128.

Cooling control module 109 can control fan 130,132,134,136, expansion valve 112,122 and/or compressor 116,118,126,128 based on the signal from each sensor.Such as, sensor can comprise environment temperature sensor 150, suction pressure sensor 152,154, discharge pressure (headpressure) sensor 156,158 and/or suction port of compressor (or evaporator outlet) temperature sensor 160,162.Environment temperature sensor 150 can be outdoor environment temperature sensor, and build environment temperature signal T _a.Suction pressure sensor 152,154 generates suction pressure signal SUC1, SUC2 and detects the pressure of the fluid that compressor 116,118,126,128 receives.Discharge pressure sensor 156,158 generates discharge pressure (or blowdown presssure) signal HEAD1, HEAD2 and detects the pressure from compressor 116,118,126,128 fluid out.Temperature sensor 160,162 detects the fluid in (i) evaporimeter 110,120 downstream and the temperature of (ii) fluid between evaporimeter 110,120 and compressor 116,118,126,128.Although not shown, pressure and/or temperature that pressure sensor and/or temperature sensor detect (i) fluid between condenser 114,124 and expansion valve 112,122 and/or (ii) fluid between expansion valve 112,122 and evaporimeter 110,120 can also be comprised.

Evaporimeter 110,120 can be microchannel (MC) cooling coil assembly, and/or comprises MC heat exchanger, and/or can be fin tube type (finandtube) cooling coil assembly.Expansion valve 112,122 can be the expansion valve (such as, EEV) based on electronics.EEV112,122 may be used for the stream of the cold-producing medium being adjusted to evaporimeter 110,120.This makes cooling system 100 can remain on suitable condition of work to control for accurate temperature, and provides cooling fast and by energy consumption minimized.Such as, suitable condition of work can comprise and the supercooling temperature of cooling system 100 (or from condenser 114,124 out) remained on predetermined supercooling temperature (such as, 5 °F) place and/or within the scope of the predetermined supercooling temperature of predetermined supercooling temperature.Term as used in this article " excessively cold " can refer to the fluid that the temperature under with the normal saturation temperature of fluid exists.

Each condenser in condenser 114,124 can be all kinds, such as air-cooled condenser, water cooled condenser or cold ethanediol cooler condenser.Condenser 114,124 can comprise the heat release of cooling medium heat being passed to such as extraneous air from Returning fluid.Heat release can comprise air-cooled heat exchanger or liquid cooled heat exchangers.

In each loop in loop 104,108, by respective compressor to 116,118, compressor carrys out circulating cooling fluid (cold-producing medium) to 126,128.Fluid flows out from compressor 116,118,126,128, through condenser 114,124, and expansion valve 112,122 and evaporimeter 110,120 and turn back to compressor 116,118,126,128.Evaporimeter 110,120 can hierarchical arrangement, makes air first flow through upstream evaporator 110 in a serial fashion and then flows through downstream evaporator 120.By making multiple cooling class arrange for serial air stream, reduce the temperature difference across evaporimeter 110,120.This then make evaporimeter 110,120 can operate under different pressures level and the pressure differential between evaporimeter 110 and condenser 114 and the pressure differential between evaporimeter 120 and condenser 124 can be reduced.

Due to the function that compressor horsepower is the pressure differential between evaporimeter and condenser, so low pressure differential is more Energy Efficient.It is right that each cooling circuit in cooling circuit 104,108 can comprise series connection (tandem) compressor (such as, compressor 116,118 or compressor 126,128).Each compressors in series can be scroll compressor (such as, compressor 116,126) or the variable-displacement scroll compressor (such as, compressor 118,128) of fixed capacity.The control signal that the scroll compressor of fixed capacity can generate based on cooling control module 109 activates (start) and stops using (shutdown).Variable-displacement scroll compressor can control via the corresponding digital signal received from cooling control module 109.

Each cooling circuit in cooling circuit 104,108 can comprise the series connection group of compressor.Each group in series connection group two compressors that can comprise equal volume discharge capacity.First compressor can be digital pulsewidth modulation (PWM) scroll compressor, and this PWM scroll compressor receives the speed and capacity that PWM percentage signal controls the first compressor.Second compressor can be the scroll compressor of the fixed speed with simple ON/OFF volume controlled.Can by the intake line of these two compressors and discharge tube concurrently pipe connect to form series connection group.Exemplarily, compressor 116,126 can be PWM scroll compressor, and compressor 118,128 can be the scroll compressor of fixed speed.Except receiving except pwm signal from cooling control module 109, the scroll compressor of fixed speed can receive ON/OFF control signal.

Series connection group compressor configuration can be controlled by the temperature of providing the capacity modulation of wide region to realize Energy Efficient to the cooling circuit of air-conditioning system.By making digital PWM scroll compressor activate before the scroll compressor of fixed speed, series connection group provides the configuration of Energy Efficient when compressor is opened.This makes series connection group can operate for part discharge capacity the volumetric displacement/capacity providing reduction effectively, until fixing scroll compressor needs other capacity.

Also with reference to Fig. 3, superheat setpoint adjustment System 200 is shown.Superheat setpoint adjustment System 200 comprises cooling control module 109 and cooling circuit 202 one of the cooling circuit 104,108 of Fig. 2 (such as).Cooling control module 109 comprises unstable module 204, compressor discharge module 206, set point module 208, summer 210, pid control module 212, expansion valve (EV) module 214, saturation block 216 and crosses thermal modules 218.Unstable module 204 determines whether there is unstable overheated condition based on superheat setpoint SET and the heat alarm SH comprising superheat value.Superheat setpoint SET is target superheat value.Superheat value SH indicates the superheat level of the compressor (such as, one of compressor 116,118,126,128) of cooling circuit 202.Unstable module 204 generates and indicates whether the unstable signal INST that there is instability condition.Unstable signal can be data signal.The determination of unstable overheated condition is further described below about Fig. 4 and Fig. 5.

Compressor discharge module 206 determines that whether the blowdown presssure of compressor is more than the first predetermined pressure PredPres ₁.Compressor discharge module 206 can compare the discharge signal CompDIS and generation discharge comparison signal DC that receive from emission sensor (such as, one of sensor 152,158).Predetermined pressure PredPres ₁can be accessed from the memory 220 storing predetermined pressure and threshold value 222.

Set point module 208 generates superheat setpoint signal SET based on unstable signal INST and discharge signal DC.Set point module 208 can generate superheat setpoint signal SET based on such as the first reconciliation statement 223.The example of reconciliation statement is provided as table 1.

Table 1-reconciliation statement

Summer 210 deducts heat alarm SH to generate error signal ERROR from superheat setpoint SET ₁.Pid control module 212 provides the control of the position of EV224 to cooling circuit 202 one of (such as, EV112,122).Pid control module 212 is based on error signal ERROR ₁generate control signal CONTROL with the position of control EV224.Pid control module 212 can have the tuner parameters of such as PID gain, and PID gain may be used for the pid value determining EV control.EV module 214 generates based on control signal CONTROL the position that EV signal adjusts EV224.EV224 is electronic control type expansion valve.

Cross thermal modules 218 and receive the sensor signal of sensor 226 (such as, sensor 154,156,160,162) from cooling circuit 202 and/or the saturation temperature SatTemp from saturation block 216.Sensor signal can comprise suction pressure signal SucPres and compressor inlet temperature signal CompINTemp.Saturation block 216 determines the saturation temperature SatTemp of compressor based on suction pressure signal SucPres.Cross thermal modules 218 can comprise the second summer 230, second summer 230 and can deduct saturation temperature SatTemp to generate heat alarm SH from compressor inlet temperature CompINTemp.

Also with reference to Fig. 4, show a part for cooling control module 109.Cooling control module 109 comprises unstable module 204, set point module 208 and memory 220.Nonsteady behavior and stable behavior are distinguished by unstable module 204.Unstable signal can present the rectilinear oscillation that amplitude is greater than predetermined threshold and/or set point.It is unstable that module 204 comprises error module 240, comparison module 242, zero crossing counter 244, zero crossing module 246, counter 248 is touched on border, module 250 is touched on border and evaluation module 252.

Error module 240 receives heat alarm SH and superheat setpoint signal SET, and can generate the second error signal ERROR ₂.Second error signal ERROR ₂generate based on the difference between heat alarm SH and set point signal SET.Such as, error signal can be sinusoidal signal.Difference between heat alarm SH and set point signal SET (or the first error signal ERROR ₁) can be integrated in time and normalization based on Moving Window as described further below.

In order to detect unstable overheated condition, error module 240 can based on Moving Window by the first error signal ERROR ₁absolute value integration in time, to generate the second error signal ERROR ₂.Moving Window may be used for restriction and is integrated to provide the second error signal ERROR ₂the amount of data history.Moving Window can comprise the first error signal ERROR of predetermined number ₁sinusoidal cycles.Can use such as that formula 1 is to determine integration, wherein t is the time and WindowSize is the size of Moving Window.

${\mathrm{ERROR}}_2={\∫}_{t-WindowSize}^t|SET-SuperHeat|dt---\left(1\right)$

Moving Window can have pre-sizing, and this pre-sizing can be stored in memory 220 and to be accessed by error module 240.Second error signal ERROR ₂amplitude A can be equaled be multiplied by WindowSize and be multiplied by 2/ π again.In order to provide Moving Window and perform the first error signal ERROR ₁integration, error module 240 can comprise timer 254, and timer 254 is incremented to the value of the size equaling window WindowSize.

Second error signal ERROR ₂can be normalized relative to baseline.Baseline can comprise size and the predetermined oscillation amplitude A of Moving Window.Predetermined oscillation amplitude A makes a comment or criticism the peak of sinusoidal cycles of string background signal and the amplitude of paddy.Predetermined oscillation amplitude A is confirmed as the maximum amplitude of vibration for stable and Dynamic System.At the first error signal ERROR ₁there is the amplitude and/or the second error signal ERROR that are greater than predetermined amplitude A ₂when being greater than predetermined threshold, instability condition can be there is.

Comparison module 242 is by the second error signal ERROR ₂with the first predetermined threshold PredThr ₁compare, and generate application condition signal EC.Application condition signal EC indicates the second error signal ERROR ₂whether be greater than the first predetermined threshold PredThr ₁.

Zero crossing counter 244 receives heat alarm SH and superheat setpoint signal SET, and makes the first count value Count when heat alarm SH equals superheat setpoint signal SET ₁increase progressively.Zero crossing module 246 determines the first count value Count ₁whether be greater than the second predetermined threshold PredThr ₂.Zero crossing module 246 generates zero crossing comparison signal ZC with instruction when the first count value Count ₁be greater than the second predetermined threshold PredThr ₂.Second predetermined threshold PredThr ₂can be normalized relative to the second baseline, the second baseline is determined by Moving Window size WindowSize and cycle of oscillation.Second predetermined threshold PredThr ₂can be configured to equal such as 1 or value in the preset range of 1.

Border is touched counter 248 and is received heat alarm SH and by heat alarm SH and preset range limits and/or predetermined value BOUNDARY (hereinafter referred to as boundary value BOUNDARY) compares.When heat alarm SH is greater than predetermined value BOUNDARY, border is touched counter 248 and is made the second count value Count ₂increase progressively.Module 250 is touched by the second count value Count in border ₂with the 3rd predetermined threshold PredThr ₃compare, and generate border comparison signal BC.Border is touched module 250 and is generated border comparison signal BC with instruction when the second count value Count ₂be greater than the 3rd predetermined threshold PredThr ₃.The 3rd baseline can determined with respect to Moving Window size WindowSize and cycle of oscillation is to the 3rd predetermined threshold PredThr ₃be normalized.3rd predetermined threshold PredThr ₃can be configured to equal 1 or value in the preset range of 1.

Module 240 to 252 is used to eliminate wrong report that whether unstable overheated condition exist and fails to report.By being normalized and integration error signal, the number of zero crossing being normalized and determining, and by being normalized the overheated number of times exceeding predetermined margin and determining, preventing and report instability condition via evaluation module 252.

Evaluation module 252 based on the comparison signal EC, ZC, BC generates unstable signal INST.Unstable signal INST can indicate exists instability condition under such as EC and ZC is genuine situation.There is raising or the reduction that instability condition triggers overheated set point signal SET (or superheat setpoint) in unstable signal INST instruction.The change of superheat setpoint signal SET can signal EC, ZC, BC based on the comparison.Method with reference to Fig. 5 further describes the superheat setpoint adjustment System 200 of Fig. 3 and Fig. 4 and the operation of unstable module 204.

Superheat setpoint adjustment System 200 can use large metering method to operate, and the method for Fig. 5 provides exemplary method.In Figure 5, the logical flow chart of diagram superheat setpoint method of adjustment is shown.Method can start at 300 places.Although the main implementation with reference to Fig. 2 to Fig. 4 of task below describes, easily can modify to task other implementations being applied to present disclosure.Can execute the task iteratively.

At 302 places, can open or reset timer 254.Can at unlatching and/or the replacement timer 254 after 332 to 346 of executing the task at every turn.

At 304 places, error module 240 determines superheat value based on heat alarm SH.At 305 places, the superheat value of the current time stamp indicated by timer is stored in memory 220.

At 307 places, unstable module 204 determines whether timer 254 equals WindowSize.Execute the task 308 when timer 254 equals WindowSize, otherwise execute the task 324.

At 308 places, error module 240 generates error signal (such as, the first error signal ERROR based on the superheat value stored during task 304 to 307 and superheat setpoint ₁).First error signal ERROR ₁value can by determining that the difference between each superheat value in superheat value and superheat setpoint generates.In Moving Window, anomalous integral normalization is carried out to generate the second error signal ERROR to error signal as mentioned above ₂.

At 309 places, as mentioned above, in Moving Window, calculate also normalization zero crossing (or first) counting Count ₁.At 310 places, as mentioned above, also normalization border counting (or second) counting Count is calculated ₂.

At 312 places, comparison module 242 determines the second error signal ERROR ₂whether be greater than the first predetermined threshold PredThr ₁and generate error (or first) comparison signal EC.At the second error signal ERROR ₂be greater than the first predetermined threshold PredThr ₁when, 314 can be executed the task, otherwise 316 can be executed the task.

At 314 places, zero crossing module 246 determines the first counting Count ₁whether be greater than the second predetermined threshold PredThr ₂and generate zero crossing (or second) comparison signal ZC.Perform this when being under stable state to compare, to prevent the first error signal ERROR ₁integration " terminate (windingup) ".Zero crossing counter 246 is used as the second examination criteria counted the number of times that heat alarm SH and superheat setpoint are intersected.If the first counting Count ₁be greater than the second predetermined threshold PredThr ₂, then execute the task 318, otherwise execute the task 316.

At 316 places, border is touched module 250 and is determined the second counting Count ₂whether be greater than the 3rd predetermined threshold PredThr ₃and generate border comparison signal BC.If the second counting Count ₂be greater than the 3rd predetermined threshold PredThr ₃, then execute the task 318, otherwise execute the task 320.

At 318 places, signal EC, ZC, BC instruction can there is unstable overheated condition in evaluation module 252 based on the comparison.This can indicate via unstable signal INST.Under task 314 or task 326 are genuine situation, there is instability condition.At 320 places, signal EC, ZC, BC instruction can there is thermal stability condition in evaluation module 252 based on the comparison.This can indicate via unstable signal INST.When task 316 is false, there is stable condition.After task 318 and 320, execute the task 322 and 332.

At 322 places, make counter decrements, stab with the very first time of Moving Window the first superheat value be associated and decline and/or delete, remaining superheat value is moved forward, and reset counting Count ₁, Count ₂.This makes the superheat value determining to upgrade during the successive iterations of task 304.During the successive iterations of task 304 to 305, determine the superheat value of renewal and it can be used as last superheat value to be stored in memory 220.Then execute the task 308 successive iterations time use the superheat value of up-to-date storage.Task 304,305,307,322 and 324 provides Moving Window, and this Moving Window is for storing the superheat value of up-to-date predetermined number.

Exemplarily, during task 304 to 307 and 324, the superheat value of the predetermined number that the size by Moving Window can be indicated is stored in starting in the first address and the address place of in the end end of address (EOA) of memory 220.When remaining superheat value moves forward, the first pointer of being associated can be stabbed from (being associated with the superheat value declined) the first address shift to the second address by with the very first time of Moving Window.Second superheat value was previously stored in the second address place.Can by with the final time of Moving Window stab be associated and the last pointer previously pointing to (being associated with last previously stored superheat value) FA final address be displaced to FA final address after address or the first address.This makes each superheat value displacement in superheat value and makes the superheat value upgraded be stored in first superheat value at subsequent addresses or overriding the first address place.

324 are executed the task after task 322.At 324 places, make timer increments.Timer 254 can increase progressively for each iteration in task 304 to 307.

Task 326 to 330 below can perform concurrently with task 302 to 324.At 326 places, the blowdown presssure that compressor (such as, one of compressor 116,118,126,128) determined by counter 248 is touched on border.At 328 places, border is touched counter 248 and is determined whether blowdown presssure CompDIS is greater than predetermined pressure PredPres ₂.Predetermined pressure PredPres is greater than at blowdown presssure CompDIS ₂when, execute the task 330, otherwise execute the task 332.

At 330 places, border is touched counter 248 and blowdown presssure (or discharge pressure) can be indicated to be maximum discharge pressure.This can have been come by the maximum discharge mark of setting such as in memory 220.

At 332 places, set point module 208 determines whether to generate unstable signal INST.326 to 330 can be finished the work finishing the work before 302 to 324.Task 332 makes to regulate superheat setpoint SET:(i in the case where there) blowdown presssure CompDIS is not less than or equal to the second predetermined pressure PredPres ₂; (ii) task 326 to 330 was done before task 302 to 324.When unstable signal INST is not generated by set point module 208 and/or received, execute the task 334, otherwise execute the task 338.

At 334 places, set point module 208 can determine whether blowdown presssure CompDIS is less than or equal to the second predetermined pressure PredPres ₂.The second predetermined pressure PredPres is less than or equal at blowdown presssure CompDIS ₂when, execute the task 336, otherwise execute the task 342.At 336 places, set point module 208 can keep (or avoid change) superheat setpoint SET.

At 338 places, the result of set point module 208 task based access control 312 to 316 determines whether there is stable condition and whether blowdown presssure CompDIS is less than or equal to the second predetermined pressure PredPres ₂.If there is stable condition and blowdown presssure CompDIS is less than or equal to the second predetermined pressure PredPres ₂.Then execute the task 336, otherwise execute the task 340.

At 340 places, the result of set point module 208 task based access control 312 to 316 determines whether there is stable condition and whether blowdown presssure CompDIS is greater than the second predetermined pressure PredPres ₂.If be true, then execute the task 342, otherwise execute the task 344.

At 342 places, set point module 208 can reduce superheat setpoint SET.Set point module 208 can determine the amount reducing superheat setpoint SET.The amount reduced can based on the second error signal ERROR ₂, blowdown presssure CompDIS, Counter Value Count ₁, Count ₂, the result of task 312,314,316 and/or 318, unstable signal INST and/or other suitable parameters and/or information.Then, set point module 208 correspondingly can reduce superheat setpoint SET.

At 344 places, the result of set point module 208 task based access control 312 to 316 determines whether there is instability condition and whether blowdown presssure CompDIS is less than or equal to the second predetermined pressure PredPres ₂.If be true, then execute the task 346, otherwise execute the task 342.

At 346 places, set point module 208 can improve superheat setpoint SET.Set point module 208 can determine the amount improving superheat setpoint SET.The amount improved can based on the second error signal ERROR ₂, blowdown presssure CompDIS, Counter Value Count ₁, Count ₂, the result of task 312,314,316 and/or 318, unstable signal INST and/or other suitable parameters and/or information.Then, set point module 208 correspondingly can improve superheat setpoint SET.

At 348 places, unstable module removing stores dsc data excessively in memory and resets count value Count ₁, Count ₂.Remove overheated data and comprise the superheat value of deleting and storing during task 304,305.Task 302 can be performed after task 348.

The set point management that above task provides, for adjusting superheat setpoint SET, makes the overheated condition of compressor carry out stabilisation for the superheat setpoint SET upgraded.Which improve robustness and the reliability of Dynamic System.

Cooling system can operate and stand various different operating condition under various varying environment.Such as, some part of cooling system can stand the indoor temperature of 60 °F to 105 °F, and other parts of cooling system can stand the outdoor temperature of-30 °F to 105 °F.Exemplarily, the evaporimeter of cooling system can be positioned at indoor and the condenser of cooling system can be positioned at outdoor.Traditionally, the superheat value of compressor is controlled so as to mate constant superheat setpoint, to guarantee the security of compressor and to improve system effectiveness.But, due to various operating condition, superheat value is remained on constant superheat setpoint value and the refrigerant charge of the difference of compressor can be caused to manage and cause unstable Dynamic System.

Example described below comprises and determines whether to regulate superheat setpoint to manage refrigerant charge between indoor pipe dish (such as, evaporimeter) Yu outdoor pipe dish (such as, condenser) to obtain stable operation.Superheat setpoint keeps based on operating condition and predetermined and/or initial value and/or regulates.Superheat setpoint is set appropriately for each operating condition in operating condition, to provide the load balance between indoor pipe dish and outdoor pipe dish with thermal stability value and indirectly to keep predetermined subcooled water to put down.

Fig. 6 illustrates the superheat setpoint regulating system 350 comprising cooling control module 109 ' and cooling circuit 202.Cooling control module 109 ' can replace the cooling control module 109 of Fig. 2.Although be shown as the module different from the cooling control module 109 of Fig. 3, cooling control module 109 ' can be cooling control module 109.In other words, single cooling control module can provide the instability of the invariant feature of the cooling control module 109 of Fig. 3 and the cooling control module 109 ' of Fig. 6 to prevent feature.If the instability condition determined by the method for such as Fig. 5 is existed, then the superheat setpoint that the corresponding superheat setpoint control method can skipping (override) superheat setpoint regulating system 350 and Fig. 7 provides controls.If instability condition exists, then can control superheat setpoint SET via the method for Fig. 5 but not based on the method for Fig. 7.If instability condition does not exist, then can perform the method for Fig. 7.Thus, if instability condition detected, then cool control module can perform the method for Fig. 5 and the method for Fig. 7, and can skip Fig. 7 method and based on Fig. 5 method regulate superheat setpoint.

Cooling control module 109 ' comprises compressor discharge module 206, set point module 208 ', summer 210, pid control module 212, expansion valve (EV) module 214, saturation block 216, crosses thermal modules 218, memory 220 and mode selection module 351.Set point module 208 ' comprises the second reconciliation statement 352.Second reconciliation statement 352 can comprise first reconciliation statement 223 of Fig. 3 and/or superheat setpoint SET is determined in the input that may be used for based on being supplied to set point module 208 '.Input is illustrated in figure 6 and is described in the following.

Memory stores predetermined pressure and threshold value 222, predetermined temperature 354 and predetermined initial SH set-point value 356.Predetermined temperature 354 and predetermined initial SH set-point value 356 can be provided by the user interface 329 of Fig. 2, and/or can be predetermined and be stored in memory 220.Different predetermined temperatures and/or predetermined initial SH set-point value can be stored in memory 220, for: dissimilar cooling system; There is the cooling system of dissimilar parts (such as, dissimilar condenser, evaporimeter, expansion valve, compressor etc.); And/or different cooling system configurations.

Mode selection module can select concrete operations pattern.Method below about Fig. 7 describes these operator schemes.Cooling circuit 202 comprises expansion valve 224 and sensor 226.Method below about Fig. 7 further describes the cooling module of control module 109 ' and the operation of device.

Fig. 7 illustrates superheat setpoint control method.Although the implementation that task below relates generally to Fig. 6 to Fig. 7 describes, task of can easily revising is to be applied to other implementations of present disclosure.Can execute the task iteratively.

Method can start at 400 places.At 402 places, measure and/or determine suction pressure SucPres, compressor inlet temperature CompINTemp, outdoor environment temperature T _a, and compressor discharge pressure CompDis.Can detect as mentioned above and/or determine these temperature and pressures.

At 404 places, as mentioned above, saturation block 216 determines saturation temperature SatTemp based on suction pressure SucPres.At 406 places, cross thermal modules 218 and determine actual superheat value SH, it is determined based on saturation temperature SatTemp and compressor inlet temperature CompINTemp.

Task 408 to 416 below can performing before task 404 to 406, during task 404 to 406 and/or after task 404 to 406.At 408 places, compressor discharge module 206 is by compressor discharge pressure CompDis and the first predetermined pressure PredPres ₁relatively to generate discharge comparison signal DC, this discharge comparison signal DC indicates compressor discharge pressure CompDis and the first predetermined pressure PredPres ₁between difference.

Task 410 below can performing before task 408, during task 408 and/or after task 408.At 410 places, mode selection module 351 can select operation in such as first mode, the second pattern, the 3rd pattern or four-mode.This selection can input based on the user of user interface 329.User can select operation in first mode, the second pattern, the 3rd pattern or four-mode.Whether this selection can based on to provide in 220 in memory and storage returns air themperature set point T _rASETor supply air themperature set point T _sASET.Return air themperature set point T _rASETrefer to the predetermined temperature being back to the air of (or being supplied to) evaporimeter.Supply air themperature set point T _sASETrefer to the predetermined temperature from evaporimeter (and/or cooling system) air out.These set points can be set via the user interface 329 of Fig. 2 by user, or can be stored in the predetermined set-points in memory 220.Predetermined temperature 354 comprises these set points.Mode selection module 351 generates the mode signal MODE of instruction selection mode.

First mode can refer to use first indoor regulatory factor AdSHid1 and outdoor regulatory factor AdSHod.Second pattern can refer to use outdoor regulatory factor AdSHod and the second indoor regulatory factor AdSHid2.First mode can not comprise the indoor regulatory factor AdSHid2 of use second.Second pattern can not comprise the indoor regulatory factor AdSHid1 of use first.3rd pattern can refer to use all regulatory factor AdSHid1, AdSHod, AdSHid2.Four-mode can refer to avoid regulating superheat setpoint SET.Although can select four-mode, this can be skipped (override) by the method for Fig. 5.

Regulatory factor AdSHid1, AdSHod, AdSHid2 can be 416 places use predetermined default value to regulate superheat setpoint SET.The setting of the cooling system that regulatory factor AdSHid1, AdSHod, AdSHid2 can be employed based on the factor and/or this cooling system are set by the operating condition used.Each dissimilar cooling system can have different values for regulatory factor AdSHid1, AdSHod, AdSHid2.In mode 3, can be weighted to provide the indoor regulatory factor obtained to indoor regulatory factor AdSHid1 and AdSHid2.To these factors be weighted can comprise these factors are multiplied by weight (or be more than or equal to 0 and be less than or equal to 1 value) and sue for peace the factor through weighting to provide the indoor regulatory factor obtained.

At 412 places, set point module 208 ' determines whether to regulate superheat setpoint SET.This is determined can based on such as mode signal MODE, discharge comparison signal DC and/or other parameters.Exemplarily, regulate superheat setpoint SET when can operate in one of pattern 1 to 3, and can not superheat setpoint SET be regulated when operating in pattern 4.As another example, if discharge comparison signal DC is greater than predetermined value, then can forbids and improve and/or regulate superheat setpoint SET.This makes superheat setpoint reduce and/or remain on current superheat setpoint place.If do not regulated superheat setpoint, then can execute the task 414.If will regulate superheat setpoint, then can execute the task 416.If allow superheat setpoint reduce and do not allow superheat setpoint to improve, then only can use the adjustment of two or more factors in the factors A dSHid1 by using for institute lectotype, AdSHod, AdSHid2 and the value obtained that provides, with when the value obtained and for regulating superheat setpoint SET negative.Corresponding entry in the formula 2 to 7 that the value obtained provides below can being.Exemplarily, the corresponding entry of AdSHid1 can be AdSHid1 ^*(T _rASET-T ₁).Limit below and describe the parameter of corresponding entry.

At 414 places, superheat setpoint SET is remained on currency place by set point module 208 '.At 416 places, set point module 208 ' regulates superheat setpoint SET.Superheat setpoint SET can regulate according to the arbitrary formula in formula 2 to 4.The selection of a formula in formula 2 to 4 can based on mode signal MODE, wherein SH _iNITit is initial superheat setpoint.Initial superheat setpoint SH _iNITit can be the predetermined initial SH value 356 be stored in memory 220.Such as, if operated in mode 1, then can select formula 2.If in pattern 2 times operations, then formula 3 can be selected.If operated under mode 3, then can select formula 4.

SET＝SH _INIT+AdSHid1 ^＊(T _RASET-T ₁)+AdSHod ^＊(T ₂-T _A)(2)

SET＝SH _INIT+AdSHid2 ^＊(T _RASET-T ₃)+AdSHod ^＊(T ₂-T _A)(3)

$\begin{array}{c}SET={\mathrm{SH}}_{INIT}+\[{W_1}^{*}AdSHid{1}^{*}(T_{RASET}-T_1)\]+{\mathrm{AdSHod}}^{*}(T_2-T_A)+\\ \[{W_2}^{*}AdSHid{2}^{*}(T_{RASET}-T_3)\]\end{array}---\left(4\right)$

Indoor regulatory factor AdSHid1 is based on returning air themperature set point T _rASETwith the first predetermined temperature T ₁(such as, 75 °F) regulate.Outdoor regulatory factor AdSHod is based on outdoor environment temperature T _awith the second predetermined temperature T ₂(such as, 95 °F) regulate.Indoor regulatory factor AdSHid2 is based on supply air themperature set point T _sASETwith the 3rd predetermined temperature T ₃(such as, 55 °F) regulate.In formula 4, indoor regulatory factor AdSHid1, AdSHid2 pass through weights W ₁, W ₂regulate.

Regulatory factor AdSHid1, AdSHod, AdSHid2 can be configured to predetermined default value, and/or the type of the cooling system that can be employed based on regulatory factor AdSHid1, AdSHod, AdSHid2 and/or setting.Exemplarily, the default value of regulatory factor AdSHid1, AdSHod, AdSHid2 can be 0.3,0.13,0.3 respectively.The default value of the second indoor regulatory factor AdSHid2 can be different from the default value of the first indoor regulatory factor AdSHid1.Predetermined temperature T ₁, T ₂, T ₃can pre-determined baseline value be configured to, and/or can based on predetermined temperature T ₁, T ₂, T ₃the type of the cooling system be employed and/or setting.If temperature T _rASET, T _a, T _sASETequal predetermined temperature T respectively ₁, T ₂, T ₃, then superheat setpoint SET equals initial superheat setpoint SH _iNIT.

Outdoor environment temperature T _acan in the predetermined amount of time (such as, 5 minutes) by average to provide mean temperature.This mean value can be determined by the set point module 208 ' in cooling control module 109 ' or thermal module (not shown).Mean temperature is outdoor environment temperature T _athe mean value of multiple readings (iteration is determined) within a predetermined period of time.Can mean temperature be used and not use outdoor environment temperature T in formula 2 to 4 provided below and/or formula 5 to 7 _a.This provides the stability of a system by preventing the change of the superheat setpoint SET caused due to the of short duration lasting fluctuation of outdoor environment temperature.Outdoor environment temperature can fluctuate due to such as fitful wind and/or other outdoor environment key elements.If (such as during start-up of cooling system) is not determined average outdoor environment temperature and/or do not determined outdoor environment temperature within a predetermined period of time, then AdSHod can there is no ^*(T ₂-T _a) item when calculate superheat setpoint SET.Therefore, one of formula 5 to 7 can be used to replace one of formula 2 to 4 accordingly.

SET＝SH _INIT+AdSHid1 ^＊(T _RASET-T ₁)(5)

SET＝SH _INIT+AdSHid2 ^＊(T _RASET-T ₃)(6)

SET＝SH _INIT+[W ₁ ^＊AdSHid1 ^＊(T _RASET-T ₁)]+[W ₂ ^＊AdSHid2 ^＊(T _RASET-T ₃)](7)

In one embodiment, if outdoor environment temperature T _abe less than or equal to predetermined temperature (such as, 50 °F), then in order to the object of formula 2 to 4, by outdoor environment temperature T _abe arranged on predetermined temperature (such as, 50 °F) place.This is because at temperature under predetermined temperature, outdoor environment temperature 50 °F is on crossing the minimum or not impact of cold impact.At temperature under predetermined temperature, the cooling fluid volume of the inner and corresponding condenser inside of corresponding evaporimeter can not change.For this reason, maintain the excessively cold of scheduled volume owing to not regulating at these tem-peratures when superheat setpoint SET, regulate so superheat setpoint SET can not be performed.At temperature under predetermined temperature, discharge comparison signal DC can remain on constant set point place.

If do not provide outdoor environment temperature because such as outdoor environment temperature sensor 150 disconnects or lost the signal from outdoor outdoor environment temperature sensor 150, then can use the previous outdoor environment temperature (T previously determined _a) as current outdoor environment temperature.If do not provide outdoor environment temperature or the respective sensor signals from outdoor environment temperature sensor 150 being less than in predetermined amount of time (such as, 1 to 2 second), then can use previous outdoor environment temperature.When the voltage drop of outdoor environment temperature signal is more than scheduled volume and/or for bearing, cooling control module 109 ' can detect the loss of outdoor environment temperature signal.This prevent due to the loss of outdoor environment temperature signal and regulate superheat setpoint SET irrelevantly.

After task 406,414 and/or 416, execute the task 418.At 418 places, the superheat setpoint SET that summer 210 provides based on set point module 208 ' generates the first error signal ERROR with the superheat level SH that thermal modules 218 provides excessively ₁.Superheat setpoint SET can be the superheat setpoint of the current superheat setpoint that provides at 414 places or the renewal at 416 places.Executing the task after 416, the superheat setpoint of renewal becomes current superheat setpoint.

At 420 places, pid control module 212 is based on the first error signal ERROR ₁generate control signal CONTROL.At 422 places, EV module 214 generates EV signal with the state of variable expansion valve 224 based on control signal CONTROL.

Described method providing of Fig. 7 to keep the robustness overheating detection of superheat setpoint and Automatic dispatching and/or regulates.By regulating superheat setpoint SET and controlling the state of expansion valve 224 based on the superheat setpoint SET through regulating, expansion valve 224 makes a response to manage evaporimeter (such as, one of evaporimeter 110,120 of Fig. 2) flow balance for system loading with the cooling agent (or cooling fluid) between condenser one of the condenser 114,124 of Fig. 2 (such as).This made coldly be kept and/or keep predeterminated level excessively cold in the porch of expansion valve 224.

The method keeps subcooled water to put down for measuring from condenser pressure out and/or from when the pressure sensor of the temperature of condenser cold-producing medium (or fluid) out and/or temperature sensor when not having to use.

The above-mentioned task of Fig. 5 and Fig. 7 is intended to illustrative example; In the period of overlap or according to the different order depending on application, can sequentially, synchronously, side by side, continuously execute the task.In addition, depend on realization and/or the order of event, can not perform or skip any one in task.

Description is above only illustrative in essence and is never intended to restriction present disclosure, its application or purposes.The broad teachings of present disclosure can be realized in a variety of manners.Therefore, although present disclosure comprises concrete example, the true scope of present disclosure should not be so limited, because other amendment will become obvious when studying accompanying drawing, description and claims.As used in this article, at least one in phrase A, B and C should be interpreted as the logic (A or B or C) using non-exclusive logic " or (OR) ", and is not appreciated that expression " at least one in A, at least one in B and C at least one ".Should be appreciated that can with one or more step in different order (or) manner of execution simultaneously, and without the need to changing the principle of present disclosure.

In this application, comprise restriction below, term " module " or term " controller " can use term " circuit " to replace.Term " module " can refer to following item, is a part for following item, or comprises: special IC (ASIC); Digital circuit, analog circuit or hybrid analog-digital simulation/digital discrete circuit; Digital circuit, analog circuit or hybrid analog-digital simulation/digital integrated electronic circuit; Combinational logic circuit; Field programmable gate array (FPGA); The processor circuit of run time version (shared, special or group); The memory circuitry (shared, special or group) of the code that storage of processor circuit performs; Other suitable hardware componenies of described function are provided; Or the above-mentioned combination of some or all, such as, in SOC(system on a chip).

Module can comprise one or more interface circuit.In some instances, interface circuit can comprise be connected to LAN (LAN), internet, wide area network (WAN) or its combination wireline interface or wave point.The function of any given module of present disclosure can be distributed between the multiple modules connected via interface circuit.Such as, multiple module can allow load balance.In another example, server (also referred to as long-range or cloud) module can represent client modules and realize some functions.

As above the term code used can comprise software, firmware and/or microcode, and can refer to program, routine, function, class, data structure and/or object.Term share processor circuit contains the single processor circuit performed from some or all codes of multiple module.Term group processor circuit contains the processor circuit performing some or all codes from one or more module with other processor circuit in combination.Multiple processor circuits of mentioning be encompassed in multiple processor circuits in separate dies, multiple processor circuits on a single die, multiple cores of single processor circuit, single processor circuit many threads, or more combination.Term shared storage circuit contains the single memory circuit stored from some or all codes of multiple module.Term group memory circuitry contains the memory circuitry storing some or all codes from one or more module with other memory in combination.

Term memory circuit is the subset of term computer-readable medium.Term computer-readable medium as used in this article does not contain the transient state signal of telecommunication or electromagnetic signal propagated by medium (such as on carrier wave); Therefore term computer-readable medium can be considered to tangible and non-transient state.The non-limiting example of non-transient state, tangible computer computer-readable recording medium is: Nonvolatile memory circuit (such as flash memory circuit, Erarable Programmable Read only Memory circuit or mask ROM circuit); Volatile memory circuit (such as static random access memorizer circuit or dynamic RAM circuit); Magnetic storage medium (such as analog or digital tape or hard disk drive); And optical storage media (such as CD, DVD or Blu-ray Disc).

Can partly or wholly realize the equipment that describes in this application and method by special-purpose computer, this special-purpose computer produces by being configured to all-purpose computer to perform one or more specific function be included in computer program.Functional block described above and flow chart key element are used as software application, and this software application can be converted into computer program by the routine work of technical staff or programmer.

Computer program comprises the processor executable be stored at least one non-transient state, tangible computer computer-readable recording medium.Computer program can also comprise or depend on stored data.Computer program can comprise: the basic input/output (BIOS) mutual with the hardware of special-purpose computer; With the device driver that the specific device of special-purpose computer is mutual; One or more operating system; User applies; Background service; Background application etc.

Computer program can comprise: the descriptive text that (i) will resolve, such as HTML (HTML) or XML (extend markup language); (ii) assembly code; (iii) object code generated from source code by compiler; (iv) source code for being performed by interpreter; (v) source code etc. for being compiled by instant compiler and performing.Only exemplarily, the grammer in language can be used to write source code, this language comprise C language, C++, C#, target C language, Haskell, Go, SQL, R, Lisp, fortran, Perl, Pascal, Curl, OCaml, hTML5, Ada, ASP (Active Server Pages), PHP, Scala, Eiffel, Smalltalk, Erlang, Ruby, visual lua and

Except non-usage phrase " for ... device " clearly record key element or use phrase " for ... operation " or " for ... step " claim to a method when, key element described in detail in the claims is all not intended to as the device in 35U.S.C. § 112 (f) implication adds functional imperative.

Claims (20)

1. a system, comprising:

Set point module, described set point module is configured to regulate superheat setpoint by returning air themperature set point or supply air themperature set point and (ii) outdoor environment temperature based on (i), indirectly controls the excessively cold of condenser;

Summer, described summer is configured to determine the error between described superheat setpoint and the superheat level of compressor;

Control module, described control module is configured to generate control signal based on described error; And

Expansion valve module, described expansion valve module is configured to the state based on described control signal Electronic Control expansion valve.

2. system according to claim 1, wherein said set point module is configured to: the initial predetermined superheat level based on described compressor regulates described superheat setpoint.

3. system according to claim 2, wherein said set point module is configured to: while determining described superheat setpoint, based on the described initial predetermined superheat level returning air themperature set point or described supply air themperature set point and (ii) described outdoor environment temperature described in (i) and regulate described compressor.

4. system according to claim 1, wherein said set point module is configured to: regulate described superheat setpoint based on the initial predetermined superheat level returning air themperature set point, (ii) described outdoor environment temperature and (iii) described compressor described in (i).

5. system according to claim 1, wherein said set point module is configured to: regulate described superheat setpoint based on the initial predetermined superheat level of supply air themperature set point, (ii) described outdoor environment temperature and (iii) described compressor (i) described.

6. system according to claim 1, also comprises the mode selection module being configured to select operating mode,

Wherein, described set point module is configured to according to selected operator scheme, based on returning air themperature set point described in (i) or (ii) described supply air themperature set point regulates described superheat setpoint.

7. system according to claim 1, wherein said set point module is configured to: change described superheat setpoint based on described outdoor environment temperature.

8. system according to claim 1, wherein said set point module is configured to: the mean value determined based on described outdoor environment temperature iteration within a predetermined period of time regulates described superheat setpoint.

9. system according to claim 1, wherein said set point module is configured to: the loss of (i) sensing chamber external environment temperature signal; And (ii) is based on the described loss of described outdoor environment temperature signal, avoid changing described superheat setpoint.

10. system according to claim 1, wherein:

Described set point module is configured to based on discharge comparison signal and avoids changing described superheat setpoint; And

Described discharge comparison signal indicates the difference between the blowdown presssure of described compressor and predetermined pressure.

11. 1 kinds of methods, comprising:

Regulate superheat setpoint by returning air themperature set point or supply air themperature set point and (ii) outdoor environment temperature based on (i), indirectly control the excessively cold of condenser;

Determine the error between described superheat setpoint and the superheat level of compressor;

Control signal is generated based on described error; And

Based on the state of described control signal Electronic Control expansion valve.

12. methods according to claim 11, the initial predetermined superheat level comprised based on described compressor regulates described superheat setpoint.

13. methods according to claim 12, also comprise: while determining described superheat setpoint, based on the described initial predetermined superheat level returning air themperature set point or described supply air themperature set point and (ii) described outdoor environment temperature described in (i) and regulate described compressor.

14. methods according to claim 11, comprising: regulate described superheat setpoint based on the initial predetermined superheat level returning air themperature set point, (ii) described outdoor environment temperature and (iii) described compressor described in (i).

15. methods according to claim 11, comprising: regulate described superheat setpoint based on the initial predetermined superheat level of supply air themperature set point, (ii) described outdoor environment temperature and (iii) described compressor (i) described.

16. methods according to claim 11, also comprise:

Select operating mode; And

According to selected operator scheme, based on returning superheat setpoint described in air themperature set point or (ii) described supply air themperature setpoint adjustments described in (i).

17. methods according to claim 11, also comprise: change described superheat setpoint based on described outdoor environment temperature.

18. methods according to claim 11, also comprise: the mean value determined based on described outdoor environment temperature iteration within a predetermined period of time regulates described superheat setpoint.

19. methods according to claim 11, also comprise:

The loss of sensing chamber's external environment temperature signal; And

Based on the described loss of described outdoor environment temperature signal, avoid changing described superheat setpoint.

20. methods according to claim 11, also comprise: avoid changing described superheat setpoint based on discharge comparison signal,

Wherein said discharge comparison signal indicates the difference between the blowdown presssure of described compressor and predetermined pressure.