CN203036904U

CN203036904U - Refrigerating heat pump unit for CO2 trans-critical cycle

Info

Publication number: CN203036904U
Application number: CN201320032668.5U
Authority: CN
Inventors: 秦海涛
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-01-22
Filing date: 2013-01-22
Publication date: 2013-07-03
Anticipated expiration: 2023-01-22

Abstract

The utility model belongs to the technical field of trans-critical CO2 refrigerating heat pumps and discloses a refrigerating heat pump unit for a CO2 trans-critical cycle. The refrigerating heat pump unit for the CO2 trans-critical cycle comprises a CO2 refrigerant compressor, a gas cooler, a heat regenerator, a throttling valve I, a gas-liquid separator, a throttling valve II, an evaporator, a controller, a pressure sensor, a temperature sensor and a superheat temperature sensor. All the components are connected into a closed system through pipelines. The controller controls the opening degree of the throttling valve I and the opening degree of the throttling valve II according to detected refrigerant pressure in the gas cooler, the refrigerant temperature at an outlet of the gas cooler, the refrigerant superheat degree at an outlet of the evaporator and the highest cooling pressure Pg of system operation, and therefore the unit can operate with high cycle efficiency. The refrigerating heat pump unit for the CO2 trans-critical cycle has the advantages that when environment temperatures or cooled room environment temperatures change, the controller can regulate the unit, and therefore the unit can operate with the high cycle efficiency; and the refrigerating heat pump unit is simple in method, easy to realize, reliable and stable.

Description

CO 2Stride the refrigerating heat pump unit of critical cycle

Technical field

The utility model belongs to strides critical CO ₂The refrigerating heat pump technical field.

Background technology

Because the material impact that CFCs warms for ozone layer and atmosphere, protection environment are realized that CFCs substitutes and are become the common problem of paying close attention in the whole world.HFCs class cold-producing medium substitutes as CFCs's, though do not damage the ozone layer, its tangible greenhouse effects are still to environment certain influence of warming.So people begin to advocate energetically use nature cold-producing medium.CO ₂The nature cold-producing medium is subjected to extensive concern, CO again ₂The research of refrigerating heat pump device becomes valued focus in the world again with application.

Of the prior artly stride critical CO ₂Refrigeration system mainly comprises compressor, cooler, regenerator, choke valve, gas-liquid separator, evaporimeter etc., prior art stride critical CO ₂The deficiency of refrigeration system is: when the residing environment of system changed, the cold-producing medium distribution in the system can change, because the HTHP CO in gas cooler ₂Cold-producing medium can not liquefy, and causes the cold-producing medium distribution in each parts bigger to the influence of system pressure, and the height pressure of refrigeration system is regulated difficulty; Owing to stride critical CO ₂Temperature and pressure be not corresponding one by one, supercritical CO ₂Heat release in cooler, variations in temperature are very big, and the bigger cooler import and export temperature difference makes strides the raising of critical cycle efficient, different outlet temperatures, and the cooling pressure of a corresponding optimum makes cycle efficieny the highest.So when environment temperature changes when causing that gas cooler exit temperature changes, can not make corresponding adjustment to cooling pressure, to guarantee that refrigeration system has the higher coefficient of performance, and different with subcritical cycle be, cooling pressure is not more low more good, but at different outlet temperatures, has an optimal value, therefore, regulate difficulty.

Summary of the invention

The utility model proposes for addressing the above problem, and its purpose is to provide a kind of CO ₂Stride the refrigerating heat pump unit of critical cycle, reasonable, brief compactness that unit arranges by the control to system cools pressure, is kept the system optimization operation.

The technical solution of the utility model is: CO ₂Stride the refrigerating heat pump unit of critical cycle, comprise CO ₂Coolant compressor, gas cooler, regenerator, the choke valve I, gas-liquid separator, the choke valve II, evaporimeter and controller, it is characterized in that: unit also comprises pressure sensor, temperature sensor and overtemperature sensor, described each parts connect into a closed-system by pipeline: exhaust outlet of compressor links to each other with the gas cooler import, the gas cooler outlet links to each other with regenerator import I, regenerator outlet I is divided into two-way, one the tunnel through linking to each other with evaporator after the choke valve II, another road links to each other with the gas-liquid separator air inlet pipe through the choke valve I, gas-liquid separator top escape pipe is communicated with the pipeline that the choke valve II links to each other with evaporator, gas-liquid separator bottom drain pipe is communicated with the pipeline that the choke valve II links to each other with evaporator, evaporator outlet links to each other with regenerator import II, regenerator outlet II links to each other with the compressor air suction mouth, pressure sensor is arranged on exhaust outlet of compressor and the pipeline that the gas cooler import links to each other, temperature sensor is arranged on the pipeline that gas cooler exports with regenerator import I links to each other, the overtemperature sensor is arranged on the pipeline of evaporator outlet, pressure sensor, the overtemperature sensor links to each other with controller by holding wire with temperature sensor.

Described choke valve I (4) is electric control valve, and choke valve II (6) is electric control valve or mechanical type control valve.

Process of refrigerastion of the present utility model is:

CO ₂Compressor sucks refrigerant gas, and the compression back is discharged high temperature and high pressure gas and entered in the gas cooler, enters cooling again in the regenerator after the gas cooler cooling, cooled CO ₂Cold-producing medium is respectively by two choke valves in parallel: throttling becomes gas-liquid two-phase CO through the choke valve II for choke valve I and the throttling of choke valve II, cold-producing medium ₂Enter into evaporimeter heat absorption vaporization, throttling becomes gas-liquid two-phase CO through the choke valve I on another road ₂Enter into gas-liquid separator, freeze through entering into evaporimeter after the top and bottom interface pipeline of gas-liquid separator and the refrigerant mixed after the choke valve II respectively again, refrigeration back cold-producing medium becomes the low-temp low-pressure gas-liquid mixture and enters into evaporimeter, enter into regenerator after heat absorption becomes overheated gas through evaporimeter, the cold-producing medium heat exchange of in regenerator, coming out with gas cooler, temperature enters into compressor suction after raising, so circulation.The utility model comes the regulating system cold-producing medium to distribute by the two-way throttling, thereby regulating system pressure remains on the optimal design operating mode.The choke valve II major control evaporator outlet degree of superheat prevents that overfeeding from causing the contracting of compressor hydraulic pressure or degree of superheat heat exchange efficiency bigger than normal to descend, and functional equivalent is in the choke valve of conventional refrigeration system; Choke valve I mainly comes the distribution of cold-producing medium in the regulating system according to cooling pressure, too high when cooling pressure, choke valve leaves greatly, makes cold-producing medium discharge increase in the cooler, and is stored in the gas-liquid separator with liquid state through after the throttling; When cooling pressure is crossed when low, choke valve I turns down, and the cold-producing medium discharge reduces in the cooler, but compressor is constantly air-breathing, the liquid refrigerant of storing in the gas-liquid separator progressively replenishes cooling pressure is improved, and gas-liquid separator is equivalent to the cushion space of cold-producing medium storage.

Pass through the utility model, when evaporimeter environment of living in or gas cooler environment of living in change, the refrigerating heat pump unit can be according to the exit refrigerant superheat degree of evaporimeter, high side pressure and the gas cooler exit temperature of system, with system control stable operation under the evaporating temperature of the best and high-pressure, thereby improve the cooling effectiveness of system, can prevent effectively that high side pressure from increasing unusually simultaneously.

The beneficial effects of the utility model are: when environment temperature or an environment temperature that is cooled change, controller can be judged and regulate unit in the detected temperature of the outlet temperature sensor of gas cooler with at the detected pressure of the pressure sensor of gas cooler import department according to cold-producing medium moves unit under high cycle efficieny: method is simple, be easy to realize, and reliable, stable.

Description of drawings

Fig. 1 is the utility model refrigerating heat pump machine set system schematic diagram.

In the accompanying drawing:

The 1-compressor; The 2-gas cooler; The 3-regenerator; 4-choke valve I; The 5-gas-liquid separator; 6-

The choke valve II; The 7-drain pipe; The 8-air inlet pipe; The 9-escape pipe; The 10-evaporimeter; The 11-pressure sensor; The 12-controller; The 13-temperature sensor; 14-overtemperature sensor.

The specific embodiment

Below, with reference to drawings and Examples the utility model is described in detail.

Stride critical CO ₂Cold-producing medium refrigerating heat pump unit comprises CO ₂Coolant compressor 1, gas cooler 2, regenerator 3, choke valve I 4, gas-liquid separator 5, choke valve II 6, evaporimeter 10, controller 12, pressure sensor 11, temperature sensor 13 and overtemperature sensor 14, each parts connects into a closed-system by pipeline: compressor 1 exhaust outlet links to each other with gas cooler 2 imports, gas cooler 2 outlets link to each other with regenerator 3 import I, regenerator 3 outlet I are divided into two-way, one the tunnel through linking to each other with evaporator after the choke valve II 6, another road links to each other with gas-liquid separator 5 entrances through choke valve I 4, gas-liquid separator 5 top escape pipes are communicated with the pipeline that choke valve II 6 links to each other with evaporator, gas-liquid separator bottom drain pipe is communicated with the pipeline that choke valve II 6 links to each other with evaporator, evaporimeter 10 outlets link to each other with regenerator 3 import II, regenerator 3 outlet II link to each other with compressor 1 air entry, pressure sensor 11 is connected on compressor 1 exhaust outlet and the pipeline that gas cooler 2 imports link to each other, temperature sensor 13 is arranged on the pipeline that gas cooler 2 exports with regenerator 3 import I link to each other, overtemperature sensor 14 is connected on the pipeline of evaporimeter 10 outlets, pressure sensor 11, overtemperature sensor 14 links to each other with controller by holding wire with temperature sensor 13.

The high temperature and high pressure gas of discharging from the high-pressure side blast pipe of compressor 1 enters into gas cooler 2, be cooled into supercritical fluid, the supercritical fluid that gas cooler 2 comes out enters into 3 li of regenerators, carry out heat exchange with the cold-producing medium that comes out from evaporimeter 10, cold-producing medium after temperature reduces is divided into two-way, and wherein 6 throttlings of one tunnel process choke valve II become saturated gas-liquid two-phase CO ₂Cold-producing medium enters into evaporimeter 10 and carries out sweat cooling, and 4 throttlings become saturated gas-liquid two-phase CO through the choke valve I on another road ₂Enter into gas-liquid separator 5, cold-producing medium carries out sweat cooling by entering into evaporimeter 10 after gas-liquid separator 5 bottom drain pipes 7 and its top escape pipe 9 and the choke valve II 6 exit refrigerant mixed.

When refrigerating heat pump device environment of living in changes, cause that cold-producing medium changes at the state of systemic circulation, controller 12 is according to the highest cooling pressure Pg of pressure sensor 11 detected gas cooler 2 inner refrigerant pressure P k, temperature sensor 13 detected gas cooler 2 outlet refrigerant temperature tk, overtemperature sensor 14 detected evaporimeter 10 outlet refrigerant superheat degree and system's operation, the aperture of control choke valve I 4 and choke valve II 6; Choke valve I 4 specifically is controlled to be; The setting optimum pressure is Pz, Pz=-0.71471+0.27243tk, and controller 12 compares Pk, Pg, three parameters of Pz: as Pz≤Pg, during and Pk＞Pz, controller 12 output signals control choke valve I 4 valve port opening are left greatly, make Pk=Pz; As Pz≤Pg, during and Pk＜Pz, controller 12 output signals control choke valve I 4 valve port opening turn down, and make Pk=Pz; As Pz＞Pg, during and Pk＞Pg, controller 12 output signals control choke valve I 4 valve port opening are left greatly, make Pk=Pg; As Pz＞Pg, during and Pk＜Pg, controller 12 output signals control choke valve I 4 valve port opening turn down, and make Pk=Pg; Choke valve II 6 specifically is controlled to be; Refrigerant superheat degree setting value is tz, when the degree of superheat is higher than setting value tz, opens big choke valve II 6, makes refrigerant superheat degree convergence setting value tz, when the degree of superheat is lower than setting value tz, turns down choke valve II 6, makes refrigerant superheat degree convergence setting value tz.

More than be an embodiment of the present utility model, the utility model is not limited only to this.For example, in the present embodiment, compressor (1) can single machine two-stage, also can be the unit single-stage; Choke valve II (6) can be electrodynamic type, also can be mechanical type; The form of gas cooler (2) and evaporimeter (10) can be various forms such as air source formula, water source type, and the pipe arrangement formation in the above-mentioned embodiment etc. is not limited thereto.

Claims

1.CO ₂Stride the refrigerating heat pump unit of critical cycle, comprise CO ₂Coolant compressor (1), gas cooler (2), regenerator (3), choke valve I (4), gas-liquid separator (5), choke valve II (6), drain pipe (7), steam inlet pipe (8), escape pipe (9), evaporimeter (10) and controller (12) is characterized in that the described critical CO that strides ₂Cold-producing medium refrigerating heat pump unit also comprises pressure sensor (11), temperature sensor (13) and overtemperature sensor, described each parts connect into a closed-system by pipeline: compressor (1) exhaust outlet links to each other with gas cooler (2) import, gas cooler (2) outlet links to each other with regenerator (3) import I, regenerator (3) outlet I is divided into two-way, one the tunnel through linking to each other with evaporator after the choke valve II (6), another road links to each other with gas-liquid separator air inlet pipe (8) through choke valve I (4), gas-liquid separator (5) top escape pipe (9) is communicated with the pipeline that choke valve II (6) links to each other with evaporator, gas-liquid separator (5) bottom drain pipe (7) is communicated with the pipeline that choke valve II (6) links to each other with evaporator, evaporimeter (10) outlet links to each other with regenerator (3) import II, regenerator (3) outlet II links to each other with compressor (1) air entry, pressure sensor (11) is arranged on compressor (1) exhaust outlet and the pipeline that gas cooler (2) import links to each other, temperature sensor (13) is arranged on the pipeline that gas cooler (2) exports with regenerator (3) import I links to each other, overtemperature sensor (14) is arranged on the pipeline of evaporimeter (10) outlet, pressure sensor (11), overtemperature sensor (14) links to each other with controller by holding wire with temperature sensor (13).

2. according to the described CO of claim 1 ₂Stride the refrigerating heat pump unit of critical cycle, it is characterized in that described choke valve I (4) is electric control valve, choke valve II (6) is electric control valve or mechanical type control valve.