CN111059663A - Ultra-low temperature air cooling module machine part heat recovery unit and control mode - Google Patents

Abstract

The invention provides a partial heat recovery unit of an ultralow temperature air cooling module machine and a control mode, belonging to the field of air conditioning systems and comprising a compressor, a hot water side heat exchanger, a high pressure side gas-liquid separator, an economizer, an air side heat exchanger and an air conditioner water side heat exchanger; the medium sequentially passes through the hot water side heat exchanger, the high-pressure side gas-liquid separator, the first electromagnetic valve, the economizer and the electronic expansion valve from the compressor to the air-conditioning water side heat exchanger, a throttling capillary tube is arranged in parallel with the electronic expansion valve, and a second electromagnetic valve is arranged on a branch circuit where the throttling capillary tube is located; in the second branch, a medium sequentially passes through the hot water side heat exchanger, the high-pressure side gas-liquid separator, the four-way reversing valve, the air side heat exchanger, the economizer and the electronic expansion valve from the compressor to the air conditioner water side heat exchanger, an outlet and an inlet of the economizer are communicated to form an auxiliary loop, and the auxiliary loop is provided with an auxiliary loop expansion valve. The compressor is stable, and the problem of low pressure jump is not easy to occur.

Description

Ultra-low temperature air cooling module machine part heat recovery unit and control mode

Technical Field

The invention belongs to the field of air conditioning systems, and relates to a partial heat recovery unit of an ultralow-temperature air cooling module machine and a control mode.

Background

Various problems can appear in current ultra-low temperature forced air cooling part heat recovery unit when actual operation, mainly include following several kinds of situations: (1) when the environment temperature is higher and the heat recovery water temperature is lower, the heat exchange capacity of a fin tube type heat exchanger (condenser) is weakened and the heat exchange capacity of the heat recovery heat exchanger is higher, at the moment, high-temperature and high-pressure gaseous refrigerants in the system enter the heat recovery heat exchanger to carry out convective heat exchange and are excessively cooled to a wet saturation area, so that the refrigerants coming out of the heat recovery heat exchanger are in a gas-liquid mixing state, for a heat pump type unit, on one hand, when the refrigerants coming out of the heat recovery heat exchanger pass through a four-way reversing valve, a large amount of liquid refrigerants easily hit the four-way reversing valve due to the fact that the refrigerants are in the gas-liquid mixing state, on the other hand, when the gas-liquid mixing refrigerants coming out of the four-way reversing valve enter the fin tube type heat exchanger, the liquid separation of each branch is not uniform, and the heat, the supercooling degree of the system is reduced, a large amount of gaseous refrigerant appears in front of the expansion valve, so that choked flow appears in the throttling process, the pipeline behind the expansion valve is seriously frosted, and the compressor frequently jumps to low pressure; 2. when the ring temperature is low and the water temperature is low, at the moment, because a condensation fan of the unit is influenced by the ring temperature or the fin temperature or the high pressure of the system, the air volume is reduced (if the air volume is not reduced, the high pressure and the low pressure of the compressor are reduced when part of the heat recovery water pump stops and does not recover heat, and the low pressure of the compressor is jumped), the capacity of the fin tube type heat exchanger is also reduced, but the heat exchange capacity in the heat recovery heat exchanger is improved, under the condition, the supercooling degree of the system is low, a large amount of gaseous refrigerant appears in front of an expansion valve, and the compressor jumps to the low; 3. when the heat recovery water pump is started from a stop state under any working condition, the high-pressure side pressure of the system is suddenly reduced to drive the low pressure to be also suddenly reduced due to the heat recovery heat exchanger participating in heat exchange and cooling of a high-temperature and high-pressure refrigerant, and the running compressor is easy to jump to the low pressure at the moment; 4. for achieving the purpose of controlling the heat exchange capacity of hot water on the heat recovery side by controlling the air volume of the condensing fan, when the condensing air volume is suddenly reduced, part of the heat recovery heat exchange capacity is improved at the moment, the high pressure of the system is improved, but the low pressure is reduced, because on one hand, the heat exchange capacity of the fin tube type heat exchanger is reduced, and on the other hand, the part of the heat recovery heat exchange capacity is improved, the refrigerant at an outlet is in a gas-liquid mixed state, the refrigerant distribution uniformity is influenced when the refrigerant enters the fin tube type heat exchanger, so that the low pressure is lower, a pipeline behind an expansion valve frosts.

(2) When the temperature of water at the air conditioner side is higher and the temperature of hot water at the hot water side is lower, the heat exchange capability at the hot water side heat exchanger side is improved, and the heat exchange capability of a shell-and-tube heat exchanger or a plate heat exchanger is reduced, so that a refrigerant coming out of the hot water side heat exchanger is in a wet saturation state and contains a large amount of liquid refrigerants, the four-way valve is easily subjected to liquid impact when passing through the four-way valve, in addition, the refrigerant distribution is uneven when entering the shell-and-tube heat exchanger or the plate heat exchanger, the supercooling degree of the system is reduced, a large amount of gaseous refrigerants are contained in front of the expansion valve, choked flow occurs in the throttling process, and a pipeline behind the expansion valve is; 2. under the conditions that the water temperature of an air conditioner side is low and the hot water temperature of a hot water side is low, the refrigerant on the high pressure side of the system is fully subjected to heat exchange, the high pressure of the system is low, the quantity of the refrigerant participating in circulation is relatively insufficient, the supercooling degree is low, the gaseous refrigerant is contained in front of an expansion valve, the low pressure of the system is reduced along with the high pressure, if the refrigerant is replenished according to the condition, the high pressure is high after the hot water pump is stopped, the refrigerant of the system is excessive under other operation working conditions, and if the refrigerant is not replenished, the finned tube heat exchanger (which is used as an evaporator at the moment) is frequently frosted; 3. when the heat recovery water pump is started from a stop state under any working condition, the heat recovery heat exchanger participates in heat exchange and cooling of high-temperature and high-pressure refrigerants, so that the high-pressure side pressure of the system is suddenly reduced, the low pressure is also suddenly reduced, and the running compressor is easy to jump to the low pressure at the moment.

Disclosure of Invention

The invention aims to solve the problems that a part of heat recovery units of an ultralow-temperature air-cooling module machine and a control mode are provided, a compressor is stable, and low pressure jumping is not easy to occur.

In order to solve the technical problems, the invention adopts the technical scheme that: the ultra-low temperature air cooling module machine comprises a heat recovery unit and a control mode, wherein the heat recovery unit comprises a compressor, a hot water side heat exchanger, a high pressure side gas-liquid separator, an economizer, an air side heat exchanger and an air conditioner water side heat exchanger;

the medium sequentially passes through a hot water side heat exchanger, a high-pressure side gas-liquid separator, a first electromagnetic valve, an economizer and an electronic expansion valve from a compressor to an air conditioner water side heat exchanger, a throttling capillary tube is arranged in parallel with the electronic expansion valve, and a second electromagnetic valve is arranged on a branch where the throttling capillary tube is located;

a medium sequentially passes through the hot water side heat exchanger, the high-pressure side gas-liquid separator, the four-way reversing valve, the air side heat exchanger, the economizer and the electronic expansion valve from the compressor to the air-conditioning water side heat exchanger, a throttling capillary tube is arranged in parallel with the electronic expansion valve, and a second electromagnetic valve is arranged on a branch circuit where the throttling capillary tube is located;

an inlet of the economizer is communicated with the compressor, an outlet of the economizer is communicated with the inlet to form an auxiliary loop, and an auxiliary loop expansion valve is arranged on the auxiliary loop;

a medium flows back to the compressor from the air conditioner water side heat exchanger through the four-way reversing valve;

and a check valve is arranged between the electronic expansion valve and the air-conditioning water side heat exchanger on the first branch, a check valve is arranged between the air side heat exchanger and the electronic expansion valve on the second branch, an outlet of the check valve on the first branch is communicated with an outlet of the check valve on the second branch through a third branch, and a high-pressure side liquid reservoir is arranged on the first branch, the second branch or the third branch.

Furthermore, a one-way valve is arranged on the third branch and flows to the second branch from the first branch, an inlet of the one-way valve on the first branch is communicated with an inlet of the one-way valve on the second branch through a fourth branch, and a one-way valve is arranged on the third branch and flows to the second branch from the first branch.

Furthermore, a low-pressure side gas-liquid separator is arranged between the four-way reversing valve and the compressor, and a first filter is arranged between the low-pressure side gas-liquid separator and the compressor.

Furthermore, the first branch and the second branch are converged and then connected with an upper end inlet of the high-pressure side liquid storage device, and an upper end outlet of the high-pressure side liquid storage device is communicated with the economizer after passing through the drying filter.

Furthermore, the first branch and the second branch are converged and then connected with an upper end inlet of the high-pressure side liquid storage device, and a lower end outlet of the high-pressure side liquid storage device is communicated with the economizer after passing through the drying filter.

Furthermore, the first branch and the second branch are respectively connected with an inlet at the upper end of the high-pressure side liquid storage device, and an outlet at the lower end of the high-pressure side liquid storage device is communicated with the economizer after passing through a drying filter.

Furthermore, a high-pressure side liquid reservoir is arranged on the third branch and is arranged at one end close to the air-conditioning water side heat exchanger.

The mode of controlling the partial heat recovery unit of the ultra-low temperature air cooling module machine is as follows:

the first solenoid valve is opened under the following conditions:

(1) starting a heat recovery water pump;

(2) the hot water temperature of the heat recovery device is less than or equal to a set value T1;

(3) when in refrigerating operation, a condensing fan in the finned tube heat exchanger system is low-speed air;

(4) when the air conditioner is in heating operation, the water temperature of the shell-and-tube heat exchanger or the plate heat exchanger at the air conditioner side is higher than a set value T2;

(5) when in refrigeration operation, the system low pressure is lower than a set value LPC 1;

(6) during heating operation, the low pressure of the system is lower than a set value LPh 1;

the condition (1) is a precondition, the first electromagnetic valve is opened as long as one of the conditions (2), (3) and (5) is met and the condition (1) is met during refrigeration, and the first electromagnetic valve is opened as long as one of the conditions (2), (4) and (6) is met and the condition (1) is met during heating;

first solenoid valve closed condition:

(1) the heat recovery water pump is closed;

(2) the hot water temperature of the heat recovery device is higher than a set value T1;

(3) when in refrigerating operation, a condensing fan in the finned tube heat exchanger system is high-speed air;

(4) when the air conditioner is in heating operation, the water temperature of the shell-and-tube heat exchanger or the plate heat exchanger on the air conditioner side is less than or equal to a set value T2;

(5) when in refrigerating operation, the system low pressure is more than or equal to a set value LPc1+ Δ Pc 1;

(6) when the heating operation is performed, the low pressure of the system is greater than or equal to a set value LPh1+ delta Ph 1;

after the condition (1) is met, whether other conditions are met or not, the first electromagnetic valve 8 is closed within a delay time t (the delay time can be set) after the heat recovery water pump is closed; if the condition (1) is not met, the first electromagnetic valve is allowed to be closed only if the conditions (2), (3) and (5) are met simultaneously during the refrigerating operation; when the heating operation is carried out, the conditions (2), (4) and (6) must be met at the same time, and the first electromagnetic valve is allowed to be closed;

if partial heat recovery water pumps are opened when the unit meets defrosting, the unit enters defrosting and simultaneously partial heat recovery water pumps are closed, the condition (1) is met, and the first electromagnetic valve is closed in a delayed mode after the heat recovery water pumps are closed.

Further, the second solenoid on condition:

(1) opening a heat recovery water pump;

(2) when in refrigeration operation, the system low pressure is lower than a set value LPC 2;

(3) during heating operation, the low pressure of the system is lower than a set value LPh 2;

the conditions (2) and (3) are judged on the basis of the condition (1), and when the conditions (1) and (2) are met during the refrigerating operation, the second electromagnetic valve is allowed to be opened; when the heating operation is performed, the second electromagnetic valve is allowed to be opened only when the conditions (1) and (3) are satisfied.

Second solenoid valve off condition:

(1) the heat recovery water pump is closed;

(2) when in refrigerating operation, the system low pressure is more than or equal to a set value LPc2+ Δ Pc 2;

(3) when the heating operation is performed, the low pressure of the system is greater than or equal to a set value LPh2+ delta Ph 2;

if the unit meets the condition (1), the conditions (2) and (3) do not need to be judged, and the second electromagnetic valve is directly closed; if the condition (1) is not met, the condition (2) is met during the refrigerating operation, and the second electromagnetic valve is directly closed; when in heating operation, as long as the condition (3) is met, the second electromagnetic valve is directly closed;

in addition, in the defrosting process, the heat recovery water pump is forcibly closed, and the second electromagnetic valve meets the condition (1) and is directly closed;

wherein: the set value of the refrigeration low pressure LPc2 is less than or equal to LPc1, and the set return difference value delta Pc2 is less than or equal to delta Pc 1;

the heating low pressure set value LPh2 is not less than LPh1, and the heating low pressure set return difference value delta Ph2 is not less than delta Ph 1.

Further, the auxiliary circuit expansion valve is opened:

(1) starting a corresponding compressor;

(2) the ambient temperature is lower than a set value Tca during refrigeration operation;

(3) the ambient temperature is lower than a set value Tha when heating operation is performed;

(4) the exhaust temperature of the compressor exceeds a set value Tcd during the refrigeration operation;

(5) the exhaust temperature of the compressor exceeds a set value Thd during heating operation;

the condition (1) is the basis of other opening conditions, other conditions can be judged only after the condition (1) is met, the auxiliary circuit expansion valve is opened if the conditions (1), (2) and (4) are met simultaneously during refrigeration, and the auxiliary circuit expansion valve is opened if the conditions (1), (3) and (5) are met simultaneously during heating;

auxiliary loop expansion valve closing condition:

(1) closing the corresponding compressor;

(2) the environment temperature is more than or equal to a set value Tca during the refrigeration operation;

(3) the ambient temperature is greater than or equal to a set value Tha during heating operation;

(4) the exhaust temperature of the compressor is lower than a set value Tcd-delta Tc during the refrigeration operation;

(5) the exhaust temperature of the compressor is lower than a set value Thd-Delta Th during heating operation;

(6) defrosting the corresponding compressor;

if the corresponding system compressor satisfies one of the conditions, the auxiliary circuit expansion valve is closed.

Compared with the prior art, the invention has the following advantages and positive effects.

1. The invention is provided with the throttling capillary tube connected with the electronic expansion valve in parallel, a branch of the throttling capillary tube is provided with the second electromagnetic valve, and the second electromagnetic valve is opened and closed strictly according to the set conditions, so that the plug flow is avoided, the heat exchange capability of the air side heat exchanger is ensured, the refrigerant distribution uniformity is ensured, the compressor stably runs, the whole unit stably runs, the high pressure and the low pressure are stable and not easy to fluctuate in the running process, the refrigerant in front of the electronic expansion valve of the main loop under any condition can be ensured to have enough supercooling degree, the low pressure fault can not occur under different ring temperatures in the starting and stopping process of the hot water pump and different hot water temperatures, and the auxiliary loop can be ensured to obtain enough refrigerant to carry out air injection enthalpy increase and simultaneously reduce the;

2. the first branch is provided with the first electromagnetic valve, and the opening and closing of the first electromagnetic valve are also strictly opened and closed according to set conditions, so that when defrosting is carried out, the first electromagnetic valve can be closed in a delayed mode, shunting and current limiting are effectively realized, frosting of a pipeline is avoided, the stability of the operation of a structure is improved, and the stable operation of the compressor is ensured;

3. set up third branch road and fourth branch road, realized thermal recovery and recycled, the structure of this application has fine the problem of having solved existence among the background art, has realized the even running of compressor, long service life.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is a flow chart of the heat recovery unit of the ultra-low temperature air-cooled modular unit and the control method of embodiment 1 of the present invention;

FIG. 2 is a flow chart of the ultra-low temperature air-cooled modular unit part heat recovery unit and control method embodiment 2 of the present invention;

FIG. 3 is a flow chart of the ultra-low temperature air-cooled modular unit part heat recovery unit and control method embodiment 3 of the present invention;

fig. 4 is a flowchart of the ultra-low temperature air-cooled modular unit part heat recovery unit and the control method embodiment 4 of the present invention.

Reference numerals:

1. a hot water side heat exchanger; 2 is a compressor; 3. a first filter; 4. a low-pressure side gas-liquid separator; 5. an air-side heat exchanger; 6. a four-way reversing valve; 7. a high pressure side gas-liquid separator; 8. a first solenoid valve; 9. a main-path electronic expansion valve; 10. drying the filter; 11. a one-way valve; 12. a high-pressure side reservoir; 13. a second solenoid valve; 14. throttling the capillary tube; 15. an auxiliary loop expansion valve; 16. an air-conditioning water side heat exchanger; 17. an economizer; 20. a first branch; 30. a second branch circuit; 40. a fourth branch; 50. a third branch; 60. and a fifth branch.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The following detailed description of specific embodiments of the invention refers to the accompanying drawings.

As shown in fig. 1, example 1: the invention relates to a part of heat recovery units of an ultralow temperature air cooling module machine and a control mode, comprising a compressor 2, a hot water side heat exchanger 1, a high pressure side gas-liquid separator 7, an economizer 17, an air side heat exchanger 5 and an air conditioner water side heat exchanger 16;

a first branch 20, from the compressor 2, the medium passes through the hot water side heat exchanger 1, the high pressure side gas-liquid separator 7, the first electromagnetic valve 8, the economizer 17, the electronic expansion valve to the air-conditioning water side heat exchanger 16 in sequence, a throttle capillary 14 is arranged in parallel with the electronic expansion valve, and a second electromagnetic valve 13 is arranged on a branch where the throttle capillary 14 is located;

a second branch 30, in which a medium passes through the hot water side heat exchanger 1, the high pressure side gas-liquid separator 7, the four-way reversing valve 6, the air side heat exchanger 5, the economizer 17, the electronic expansion valve to the air-conditioning water side heat exchanger 16 in sequence from the compressor 2, a throttle capillary 14 is arranged in parallel with the electronic expansion valve, and a second electromagnetic valve 13 is arranged on a branch where the throttle capillary 14 is located;

an inlet of the economizer 17 is communicated with the compressor 2, an outlet of the economizer 17 is communicated with the inlet to form an auxiliary loop, and an auxiliary loop expansion valve 15 is arranged on the auxiliary loop;

a fifth branch 60, wherein the medium flows back to the compressor 2 after passing through the four-way reversing valve 6 from the air conditioner water side heat exchanger 16;

a check valve 11 is arranged on the first branch 20 between the electronic expansion valve and the air-conditioning water side heat exchanger 16, a check valve 11 is arranged on the second branch 30 between the air side heat exchanger 5 and the electronic expansion valve, an outlet of the check valve 11 on the first branch 20 is communicated with an outlet of the check valve 11 on the second branch 30 through a third branch 50, and a high-pressure side liquid reservoir 12 is arranged on the first branch 20, the second branch 30 or the third branch 50 to ensure the output and supplement of the refrigerant.

Preferably, the third branch 50 is provided with a check valve 11 and flows from the first branch 20 to the second branch 30, an inlet of the check valve 11 on the first branch 20 is communicated with an inlet of the check valve on the second branch 30 through the fourth branch 40, and the third branch 50 is provided with a check valve 11 and flows from the first branch 20 to the second branch 30.

Preferably, a low-pressure side gas-liquid separator 4 is provided between the four-way selector valve 6 and the compressor 2, and a first filter 3 is provided between the low-pressure side gas-liquid separator 4 and the compressor 2.

Preferably, the first branch 20 and the second branch 30 join together and then are connected to the upper inlet of the high-pressure side accumulator 12, and the upper outlet of the high-pressure side accumulator 12 is communicated with the economizer 17 after passing through the filter-drier 10, in this embodiment, the resistance loss of the first branch 20 and the second branch 30 needs to be considered, so as to ensure that the pressure difference between the first branch 20 and the second branch 30 is consistent, the pressure difference is consistent, and is not completely consistent, but within a certain pressure difference range, and the pressure difference is close, so that the refrigerant can be prevented from directly entering the high-pressure side accumulator 12 after the first electromagnetic valve 8 is opened, and the refrigerant on the second branch 30 is prevented from entering the high-pressure side accumulator 12 to a certain extent, and the balance of the pipelines can not be realized.

As shown in fig. 2, example 2: different from the above structure, the upper end import that connects high-pressure side reservoir 12 after first branch road 20 and second branch road 30 converge, the lower extreme export of high-pressure side reservoir 12 communicates with economic ware 17 behind drier-filter 10, and this mainly used deals with the condition of gaseous refrigerant in the output of high-pressure side reservoir 12, makes things convenient for the in-process of the just start-up operation of system, and the refrigerant is exported, avoids the refrigerant undulant, promotes compressor 2's stability.

As shown in fig. 3, example 3: different from embodiment 1, the first branch 20 and the second branch 30 are respectively connected to the inlet at the upper end of the high-pressure side reservoir 12, the pressure difference between the first branch 20 and the second branch 30 does not need to be considered, the resistance design requirement of the pipeline is reduced, the outlet at the lower end of the high-pressure side reservoir 12 is communicated with the economizer 17 after passing through the drying filter 10, and the output is more balanced and stable.

As shown in fig. 4, example 4: different from the embodiment 1, the third branch 50 is provided with the high-pressure side accumulator 12 and is arranged at one end close to the air-conditioning water side heat exchanger 16, and the high-pressure side accumulator 12 is used in the heating process, so that the supplement of the refrigerant is realized, and the heating effect is ensured.

The invention is suitable for the ultra-low temperature movement of-15 to-30 ℃, mainly realizes the heating function and keeps the refrigeration effect, the working process of the implementation 2 is taken as an example for description, and the working processes of other embodiments are the same as the embodiment 2.

In the practical application process, during refrigeration, high-temperature and high-pressure superheated gaseous refrigerant discharged by a compressor 2 firstly passes through a hot water side heat exchanger 1 for sensible heat exchange, then passes through a high-pressure side gas-liquid separator 7 for gaseous refrigerant to be discharged into a four-way reversing valve 6 from the upper side, liquid refrigerant is discharged from the lower side, passes through a first electromagnetic valve 8 and then enters a high-pressure side liquid reservoir 12, gaseous refrigerant discharged from the four-way reversing valve enters an air side heat exchanger 5, the air side heat exchanger 5 is a fin-tube type heat exchanger system (condenser), is cooled and heat exchanged again and then enters the high-pressure side liquid reservoir 12, when an auxiliary loop expansion valve 15 meets the valve opening condition, a part of refrigerant is throttled by the auxiliary loop expansion valve 15 and then enters an economizer 17 for heat absorption and then enters an air supplement port of the compressor 2 to complete auxiliary loop circulation, and in addition, the main, The throttling capillary tube 14 (when the second electromagnetic valve 13 meets the valve opening condition) enters the air-conditioning water side heat exchanger 16, the air-conditioning water side heat exchanger 16 is a shell-and-tube heat exchanger or a plate heat exchanger (evaporator), and then enters the low-pressure gas-liquid separator through the four-way reversing valve 6 and then returns to the compressor 2 to complete a refrigeration part heat recovery cycle.

During heating, high-temperature and high-pressure superheated gaseous refrigerant discharged by a compressor 2 firstly passes through a hot water side heat exchanger 1 to perform sensible heat exchange, then passes through a high-pressure side gas-liquid separator 7 to be discharged into a four-way reversing valve 6 from the upper side, liquid refrigerant is tapped out from the lower side, passes through a first electromagnetic valve 8 and then enters a high-pressure side liquid reservoir 12, the gaseous refrigerant discharged from the four-way reversing valve 6 enters an air-conditioning water side heat exchanger 16, the air-conditioning water side heat exchanger 16 is a shell-and-tube heat exchanger or a plate heat exchanger (condenser), is cooled by heat exchange again and then enters the high-pressure side liquid reservoir 12, if an auxiliary loop expansion valve 15 meets the valve opening condition, a part of refrigerant enters an economizer 17 after throttling through the auxiliary loop expansion valve 15 to absorb heat; the main loop refrigerant passes through a main loop expansion valve, a second electromagnetic valve 13 and a throttle capillary tube 14 (the second electromagnetic valve 13 meets the valve opening condition), enters a finned tube type heat exchanger system (an evaporator), absorbs heat from ambient air, enters a low-pressure side gas-liquid separator 4 through a four-way reversing valve 6, and returns to a compressor 2 to complete a heating part heat recovery cycle.

A system control program:

opening condition of the first electromagnetic valve 8:

(1) starting a heat recovery water pump;

(2) the hot water temperature of the heat recovery device is less than or equal to a set value T1;

(3) when in refrigerating operation, a condensing fan in the finned tube heat exchanger system is low-speed air;

(4) when the air conditioner is in heating operation, the water temperature of the shell-and-tube heat exchanger or the plate heat exchanger at the air conditioner side is higher than a set value T2;

(5) when in refrigeration operation, the system low pressure is lower than a set value LPC 1;

(6) during heating operation, the system low pressure is below the set point LPh 1.

The condition (1) is a precondition, the first electromagnetic valve 8 is opened as long as one of the conditions (2), (3) and (5) is satisfied and the condition (1) is satisfied during cooling, and the first electromagnetic valve 8 is opened as long as one of the conditions (2), (4) and (6) is satisfied and the condition (1) is satisfied during heating.

First solenoid valve 8 closed condition:

(1) the heat recovery water pump is closed;

(2) the hot water temperature of the heat recovery device is higher than a set value T1;

(3) when in refrigerating operation, a condensing fan in the finned tube heat exchanger system is high-speed air;

(4) when the air conditioner is in heating operation, the water temperature of the shell-and-tube heat exchanger or the plate heat exchanger on the air conditioner side is less than or equal to a set value T2;

(5) when in refrigerating operation, the system low pressure is more than or equal to a set value LPc1+ Δ Pc 1;

(6) when the heating operation is performed, the low pressure of the system is greater than or equal to a set value LPh1+ delta Ph 1;

after the condition (1) is met, whether other conditions are met or not, the first electromagnetic valve 88 is closed within a delay time t (the delay time can be set) after the heat recovery water pump is closed; if the condition (1) is not met, the first electromagnetic valve 8 is allowed to be closed only if the conditions (2), (3) and (5) are met simultaneously during the refrigerating operation; during heating operation, the conditions (2), (4), and (6) must be satisfied at the same time, and the first electromagnetic valve 8 is allowed to be closed.

If partial heat recovery water pump is opened when the unit meets defrosting, the unit enters defrosting and the partial heat recovery water pump is closed at the same time, the condition (1) is met, and the first electromagnetic valve 8 is closed after the heat recovery water pump is closed for delay time t.

Opening condition of the second electromagnetic valve 13:

(1) opening a heat recovery water pump;

(2) when in refrigeration operation, the system low pressure is lower than a set value LPC 2;

(3) during heating operation, the low pressure of the system is lower than a set value LPh 2;

the conditions (2) and (3) are judged on the basis of the condition (1), and when the conditions (1) and (2) are met during the refrigerating operation, the second electromagnetic valve 13 is allowed to be opened; in the heating operation, the second electromagnetic valve 13 is allowed to be opened only when the conditions (1) and (3) are satisfied.

Second solenoid valve 13 closed condition:

(1) the heat recovery water pump is closed;

(2) when in refrigerating operation, the system low pressure is more than or equal to a set value LPc2+ Δ Pc 2;

(3) when the heating operation is performed, the low pressure of the system is greater than or equal to a set value LPh2+ delta Ph 2;

if the unit meets the condition (1), the conditions (2) and (3) do not need to be judged, and the second electromagnetic valve 13 is directly closed; if the condition (1) is not met, the condition (2) is met during the refrigerating operation, and the second electromagnetic valve 13 is directly closed; in the heating operation, the second electromagnetic valve 13 is directly closed as long as the condition (3) is satisfied.

In addition, during defrosting, the heat recovery water pump is forcibly closed, and at the moment, the second electromagnetic valve 13 is directly closed when meeting the condition (1).

Wherein:

the set value of the refrigeration low pressure LPc2 is less than or equal to LPc1, and the set return difference value delta Pc2 is less than or equal to delta Pc 1;

the heating low pressure set value LPh2 is not more than LPh1, and the heating low pressure is set back to the difference value delta Ph2 is not more than delta Ph 1;

and the above set values may be set in a program by a low pressure sensor or satisfy the control strategy by selecting a low pressure switch of the corresponding value.

Opening conditions of the auxiliary circuit expansion valve 15:

(1) corresponding to the compressor 2 being started;

(2) the ambient temperature is lower than a set value Tca during refrigeration operation;

(3) the ambient temperature is lower than a set value Tha when heating operation is performed;

(4) the exhaust temperature of the compressor 2 exceeds a set value Tcd during the refrigeration operation;

(5) the exhaust temperature of the compressor 2 exceeds a set value Thd during heating operation;

the condition (1) is the basis of other opening conditions, and other conditions can be judged only when the condition (1) is met, the auxiliary circuit expansion valve 15 is opened if the conditions (1), (2) and (4) are met simultaneously during refrigeration, and the auxiliary circuit expansion valve 15 is opened if the conditions (1), (3) and (5) are met simultaneously during heating.

Auxiliary circuit expansion valve 15 closing condition:

(1) corresponding to the compressor 2 being turned off;

(2) the environment temperature is more than or equal to a set value Tca during the refrigeration operation;

(3) the ambient temperature is greater than or equal to a set value Tha during heating operation;

(4) the exhaust temperature of the compressor 2 is lower than a set value Tcd-delta Tc during the refrigeration operation;

(5) the exhaust temperature of the compressor 2 is lower than a set value Thd-Delta Th during heating operation;

(6) corresponding to the compressor 2 going into defrost.

If one of the conditions is satisfied for the system compressor 2, the auxiliary circuit expansion valve 15 is closed.

And the above set values may be set in a program by a low pressure sensor or satisfy the control process by selecting a low pressure switch of a corresponding value.

While one embodiment of the present invention has been described in detail, the description is only a preferred embodiment of the present invention and should not be taken as limiting the scope of the invention. All equivalent changes and modifications made within the scope of the present invention shall fall within the scope of the present invention.

Claims (10)

1. Ultra-low temperature air cooling module machine part heat recovery unit, its characterized in that: the system comprises a compressor, a hot water side heat exchanger, a high-pressure side gas-liquid separator, an economizer, an air side heat exchanger and an air conditioner water side heat exchanger;

the medium sequentially passes through a hot water side heat exchanger, a high-pressure side gas-liquid separator, a first electromagnetic valve, an economizer and an electronic expansion valve from a compressor to an air conditioner water side heat exchanger, a throttling capillary tube is arranged in parallel with the electronic expansion valve, and a second electromagnetic valve is arranged on a branch where the throttling capillary tube is located;

a medium sequentially passes through the hot water side heat exchanger, the high-pressure side gas-liquid separator, the four-way reversing valve, the air side heat exchanger, the economizer and the electronic expansion valve from the compressor to the air-conditioning water side heat exchanger, a throttling capillary tube is arranged in parallel with the electronic expansion valve, and a second electromagnetic valve is arranged on a branch circuit where the throttling capillary tube is located;

an inlet of the economizer is communicated with the compressor, an outlet of the economizer is communicated with the inlet to form an auxiliary loop, and an auxiliary loop expansion valve is arranged on the auxiliary loop;

a medium flows back to the compressor from the air conditioner water side heat exchanger through the four-way reversing valve;

and a check valve is arranged between the electronic expansion valve and the air-conditioning water side heat exchanger on the first branch, a check valve is arranged between the air side heat exchanger and the electronic expansion valve on the second branch, an outlet of the check valve on the first branch is communicated with an outlet of the check valve on the second branch through a third branch, and a high-pressure side liquid reservoir is arranged on the first branch, the second branch or the third branch.

2. The ultra-low temperature air-cooled modular machine portion heat recovery unit of claim 1, wherein: the third branch is provided with a one-way valve and flows to the second branch from the first branch, the inlet of the one-way valve on the first branch is communicated with the one-way inlet on the second branch through a fourth branch, and the third branch is provided with a one-way valve and flows to the second branch from the first branch.

3. The ultra-low temperature air-cooled modular machine portion heat recovery unit of claim 1, wherein: and a low-pressure side gas-liquid separator is arranged between the four-way reversing valve and the compressor, and a first filter is arranged between the low-pressure side gas-liquid separator and the compressor.

4. The ultra-low temperature air-cooled modular machine portion heat recovery unit of claim 1, wherein: the first branch and the second branch are connected with an upper end inlet of the high-pressure side liquid storage device after being converged, and an upper end outlet of the high-pressure side liquid storage device is communicated with the economizer after passing through the drying filter.

5. The ultra-low temperature air-cooled modular machine portion heat recovery unit of claim 1, wherein: the first branch and the second branch are converged and then connected with an upper end inlet of the high-pressure side liquid storage device, and a lower end outlet of the high-pressure side liquid storage device is communicated with the economizer after passing through a drying filter.

6. The ultra-low temperature air-cooled modular machine portion heat recovery unit of claim 1, wherein: the first branch and the second branch are respectively connected with an upper end inlet of the high-pressure side liquid storage device, and a lower end outlet of the high-pressure side liquid storage device is communicated with the economizer after passing through the drying filter.

7. The ultra-low temperature air-cooled modular machine portion heat recovery unit of claim 1, wherein: and the third branch is provided with a high-pressure side liquid reservoir and is arranged at one end close to the air-conditioning water side heat exchanger.

8. A method for controlling the ultra-low temperature air-cooled modular machine part heat recovery unit according to any one of claims 1 to 7, characterized in that:

the first solenoid valve is opened under the following conditions:

(1) starting a heat recovery water pump;

(2) the hot water temperature of the heat recovery device is less than or equal to a set value T1;

(3) when in refrigerating operation, a condensing fan in the finned tube heat exchanger system is low-speed air;

(4) when the air conditioner is in heating operation, the water temperature of the shell-and-tube heat exchanger or the plate heat exchanger at the air conditioner side is higher than a set value T2;

(5) when in refrigeration operation, the system low pressure is lower than a set value LPC 1;

(6) during heating operation, the low pressure of the system is lower than a set value LPh 1;

the condition (1) is a precondition, the first electromagnetic valve is opened as long as one of the conditions (2), (3) and (5) is met and the condition (1) is met during refrigeration, and the first electromagnetic valve is opened as long as one of the conditions (2), (4) and (6) is met and the condition (1) is met during heating;

first solenoid valve closed condition:

(1) the heat recovery water pump is closed;

(2) the hot water temperature of the heat recovery device is higher than a set value T1;

(3) when in refrigerating operation, a condensing fan in the finned tube heat exchanger system is high-speed air;

(4) when the air conditioner is in heating operation, the water temperature of the shell-and-tube heat exchanger or the plate heat exchanger on the air conditioner side is less than or equal to a set value T2;

(5) when in refrigerating operation, the system low pressure is more than or equal to a set value LPc1+ Δ Pc 1;

(6) when the heating operation is performed, the low pressure of the system is greater than or equal to a set value LPh1+ delta Ph 1;

after the condition (1) is met, whether other conditions are met or not, the first electromagnetic valve 8 is closed within a delay time t (the delay time can be set) after the heat recovery water pump is closed; if the condition (1) is not met, the first electromagnetic valve is allowed to be closed only if the conditions (2), (3) and (5) are met simultaneously during the refrigerating operation; when the heating operation is carried out, the conditions (2), (4) and (6) must be met at the same time, and the first electromagnetic valve is allowed to be closed;

if partial heat recovery water pumps are opened when the unit meets defrosting, the unit enters defrosting and simultaneously partial heat recovery water pumps are closed, the condition (1) is met, and the first electromagnetic valve is closed in a delayed mode after the heat recovery water pumps are closed.

9. The method for controlling a ultra-low temperature air-cooled modular machine portion heat recovery unit of claim 8, further comprising:

opening conditions of the second solenoid:

(1) opening a heat recovery water pump;

(2) when in refrigeration operation, the system low pressure is lower than a set value LPC 2;

(3) during heating operation, the low pressure of the system is lower than a set value LPh 2;

the conditions (2) and (3) are judged on the basis of the condition (1), and when the conditions (1) and (2) are met during the refrigerating operation, the second electromagnetic valve is allowed to be opened; when the heating operation is performed, the second electromagnetic valve is allowed to be opened only when the conditions (1) and (3) are satisfied.

Second solenoid valve off condition:

(1) the heat recovery water pump is closed;

(2) when in refrigerating operation, the system low pressure is more than or equal to a set value LPc2+ Δ Pc 2;

(3) when the heating operation is performed, the low pressure of the system is greater than or equal to a set value LPh2+ delta Ph 2;

if the unit meets the condition (1), the conditions (2) and (3) do not need to be judged, and the second electromagnetic valve is directly closed; if the condition (1) is not met, the condition (2) is met during the refrigerating operation, and the second electromagnetic valve is directly closed; when in heating operation, as long as the condition (3) is met, the second electromagnetic valve is directly closed;

in addition, in the defrosting process, the heat recovery water pump is forcibly closed, and the second electromagnetic valve meets the condition (1) and is directly closed;

wherein: the set value of the refrigeration low pressure LPc2 is less than or equal to LPc1, and the set return difference value delta Pc2 is less than or equal to delta Pc 1;

the heating low pressure set value LPh2 is not less than LPh1, and the heating low pressure set return difference value delta Ph2 is not less than delta Ph 1.

10. The method for controlling a ultra-low temperature air-cooled modular machine portion heat recovery unit of claim 8, further comprising:

opening conditions of the auxiliary loop expansion valve:

(1) starting a corresponding compressor;

(2) the ambient temperature is lower than a set value Tca during refrigeration operation;

(3) the ambient temperature is lower than a set value Tha when heating operation is performed;

(4) the exhaust temperature of the compressor exceeds a set value Tcd during the refrigeration operation;

(5) the exhaust temperature of the compressor exceeds a set value Thd during heating operation;

the condition (1) is the basis of other opening conditions, other conditions can be judged only after the condition (1) is met, the auxiliary circuit expansion valve is opened if the conditions (1), (2) and (4) are met simultaneously during refrigeration, and the auxiliary circuit expansion valve is opened if the conditions (1), (3) and (5) are met simultaneously during heating;

auxiliary loop expansion valve closing condition:

(1) closing the corresponding compressor;

(2) the environment temperature is more than or equal to a set value Tca during the refrigeration operation;

(3) the ambient temperature is greater than or equal to a set value Tha during heating operation;

(4) the exhaust temperature of the compressor is lower than a set value Tcd-delta Tc during the refrigeration operation;

(5) the exhaust temperature of the compressor is lower than a set value Thd-Delta Th during heating operation;

(6) defrosting the corresponding compressor;

if the corresponding system compressor satisfies one of the conditions, the auxiliary circuit expansion valve is closed.

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