CN110173923A - A kind of two-period form lithium bromide absorption type heat pump unit of single-action heating double-effect refrigeration - Google Patents

Abstract

The invention relates to a two-stage lithium bromide absorption heat pump unit with single-effect heating and double-effect refrigeration, belonging to the technical field of refrigeration equipment. The unit includes steam generator I, condenser I, evaporator I, absorber I, heat exchanger I, solution pump I, refrigerant pump I, steam generator II, low pressure generator, condenser II, evaporator II , Absorber II, Heat Exchanger II, Solution Pump II, Refrigerant Pump II, Stop Valve A, Stop Valve B. A single-effect heating and double-effect cooling two-stage lithium bromide absorption heat pump unit of the present invention is switched through a valve. When operating in the heating condition in winter, the unit operates according to the principle of the two-stage heat pump; in summer, the unit operates in the cooling condition. It operates according to the steam double-effect solution parallel refrigeration process. At the same time, the refrigeration performance coefficient of double-effect refrigeration is greatly improved, saving steam consumption, one machine with two functions, reducing the initial investment of equipment and saving floor space.

Description

A two-stage lithium bromide absorption heat pump unit with single-effect heating and double-effect refrigeration

technical field

The invention relates to a two-stage lithium bromide absorption heat pump unit with single-effect heating and double-effect refrigeration, belonging to the technical field of refrigeration equipment.

Background technique

In areas where heat sources are required in production processes and life, and low-temperature waste heat is required, and deep recovery of waste heat is required, the waste water has a large cooling range and low temperature, and the hot water produced has a high temperature rise and a large temperature difference. A multi-stage first-class lithium bromide absorption heat pump unit will be used (as shown in Figure 1 is a two-stage steam-type first-class lithium bromide absorption heat pump unit), which can save a large amount (more than 40%) of medium-pressure steam consumption and realize energy integration. use. In some occasions, not only heating is required in winter, but cooling is also required in summer. In order to be able to use one machine for dual purposes and save initial investment, steam-type first-class lithium bromide absorption heat pump units with cooling function have appeared in the past two years (as shown in Figure 2) , the unit's heating coefficient of performance is about 1.7, and the cooling performance coefficient is about 0.75. In the case of deep recovery of waste heat, it is not easy to use the unit shown in Figure 2, which will result in a small heat transfer temperature difference, a large heat transfer area, and high unit material costs. In order to meet the heating requirements, the heat pump unit needs to adopt a two-stage type. However, how to achieve double-effect refrigeration on the two-stage heat pump unit, improve the refrigeration performance coefficient, save steam, and reduce the heat exchange area of the unit, reduce the material cost of the unit, and be easy to operate, whether it is heating or cooling , safe and reliable, has become one of the important topics of current research.

Contents of the invention

The purpose of the present invention is to solve the above-mentioned background problems and provide a two-stage lithium bromide absorption heat pump unit with single-effect heating and double-effect refrigeration. , Save energy, reduce initial investment, one machine with dual functions, compact structure, simple operation, safe and reliable.

The purpose of the present invention is achieved like this: a two-stage lithium bromide absorption unit for single-effect heating and double-effect refrigeration, comprising a steam generator 1, a condenser 1, an evaporator 1, an absorber 1, a heat exchanger 1, a solution Pump I, refrigerant pump I, steam generator II, condenser II, evaporator II, absorber II, heat exchanger II, solution pump II and refrigerant pump II.

The generator condenser housing of the unit also includes cavity I and cavity II;

Both the condenser 1 and the steam generator 1 are arranged in the cavity 1;

Both the steam generator II and the condenser II are arranged in the cavity II;

A low pressure generator is also added in the cavity II;

A refrigerant steam connecting pipe is arranged between the gas phase region of the steam generator 1 and the tube side inlet of the low-pressure generator;

A low-pressure generator refrigerant water pipe is set between the tube-side outlet of the low-pressure generator and the U-shaped pipe I inlet of the condenser 1;

A cut-off valve B is set on the hot water pipeline from condenser II to condenser I;

A cooling water outlet pipe is arranged on the hot water pipeline between the outlet condenser II and the shut-off valve B, and a shut-off valve A is arranged on the cooling water outlet pipe.

The low-pressure generator is arranged above or below the steam generator II.

The second steam inlet pipeline of the cavity I is provided with a steam electric regulating valve A;

A steam electric regulating valve B is also arranged on the first steam inlet pipeline of the cavity II. There is also a U-shaped tube II between the condenser II and the evaporator II. The refrigerant vapor generated by the low-pressure generator condensing the dilute solution enters the condenser II to condense, and the condensed refrigerant water enters the U-shaped tube II and then evaporates. Flash within Device II.

During the heating operation of the heat pump in winter, the low-pressure generator stops working, the stop valve A is closed, the stop valve B is opened, the concentrated solution valve A and the concentrated solution valve B can adjust the flow of the corresponding concentrated solution, the refrigerant water valve A and the refrigerant water valve B can adjust the corresponding refrigerant water flow and maintain the pressure difference between the chambers. The unit operates according to the working principle of the two-stage lithium bromide absorption heat pump: steam generator I, condenser I, evaporator I, absorber I and heat exchange Device I forms a heat pump cycle in the low temperature section; steam generator II, condenser II, evaporator II, absorber II and heat exchanger II form a heat pump cycle in the high temperature section. Due to the low temperature of the refrigerant vapor in the tube side of the low-pressure generator, the solution is not concentrated, which is equivalent to stopping the work. The steam from the external system is connected in parallel and enters steam generator I and steam generator II through steam electric regulating valves A and B respectively. The cooling heat of the tube side flows out of the unit after being utilized; the hot water is connected in series to absorber I, absorber II, condenser II, and condenser I. After the tube side completes the entire heating process, it supplies heat to the user.

When operating in double-effect cooling mode in summer, shut-off valve A is opened, shut-off valve B is closed, steam electric regulating valve B is closed, condenser I and steam generator II stop working, concentrated solution valve A and concentrated solution valve B can adjust the corresponding concentration Solution flow, refrigerant water valve A and refrigerant water valve B can adjust the corresponding refrigerant water flow and maintain the pressure difference between the chambers, the steam generator I becomes the high-pressure generator of the double-effect refrigeration unit, and the high-pressure generator , low-pressure generator, condenser II, evaporator I, absorber I, heat exchanger I and evaporator II, absorber II, heat exchanger II constitute a steam double-effect refrigeration unit in which the evaporator absorber is divided into two sections, The unit operates according to the steam double-effect solution parallel refrigeration process. The steam from the external system enters the tube side of the steam generator I through the electric steam regulating valve A to condense the dilute solution into water and flows out of the unit; the cooling water enters the absorber I in series first, then enters the absorber II, and then enters the condenser II tube side to take the heat out Unit; the cold water enters the evaporator II first in series and then enters the evaporator I to cool down in the tube side to become the cold water supply for the cold user.

The beneficial effects of the present invention are:

Through the above-mentioned new process and valve adjustment and switching, the thermal field and flow field of the heat pump with completely different heating and cooling conditions can be operated safely and reliably on the same unit, realizing the deep recovery of waste heat in winter and the operation in summer. The purpose of double-effect refrigeration is to cool down or heat up the water system in stages, which increases the concentration difference of the unit solution and the heat transfer temperature difference, so that the heat transfer area of the unit is reduced, and the material cost is reduced. Because it is double-effect refrigeration, the refrigeration performance coefficient is greatly improved. , save a lot of energy, one machine with two uses, reduce the initial investment of equipment, and save the space occupied by the equipment. Therefore, the present invention can save energy and reduce emissions during heating in winter to achieve comprehensive utilization of energy, and can produce cold sources for air conditioning and production processes in summer, which improves the annual operating utilization rate of the unit and has very good economic and social benefits.

Description of drawings

Figure 1 is the working flow chart of the previous two-stage steam type first type lithium bromide absorption heat pump unit.

Fig. 2 is a working flow chart of the steam type I lithium bromide absorption heat pump unit with refrigeration function in the past.

Fig. 3 is a working flow diagram of a two-stage lithium bromide absorption unit with single-effect heating and double-effect refrigeration according to the present invention.

Fig. 4 is a working flow chart of another embodiment of a two-stage lithium bromide absorption unit for single-effect heating and double-effect refrigeration according to the present invention.

in:

Generator 1, condenser 2, evaporator 4, absorber 5, heat exchanger 3, solution pump 6, refrigerant pump 7, steam electric regulating valve 8, cooling water bypass valve 9, U-shaped pipe 10.

Steam electric regulating valve A11, condenser I12, steam generator I13, steam generator II14, condenser II15, steam electric regulating valve B16, heat exchanger II17, concentrated solution valve B18, U-shaped pipe II19, refrigerant water valve B20 , absorber II21, evaporator II22, refrigerant pump II23, solution pump II24, solution pump I25, refrigerant pump I26, evaporator I27, absorber I28, U-shaped tube I29, refrigerant water valve A30, heat exchanger I31 , Concentrated solution valve A32, stop valve A33, stop valve B34, refrigerant steam communication pipe 35, low pressure generator 36, low pressure generator refrigerant water pipe 37, cavity I50, cavity II51;

First steam inlet 38, first condensate outlet 39, cold water outlet 40, residual hot water outlet 41, cold water inlet 42, residual hot water inlet 43, cooling water inlet 44, heating hot water inlet 45, heating hot water outlet 46, Cooling water outlet 47 , second steam inlet 48 , second condensate outlet 49 .

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 3, a two-stage lithium bromide absorption unit with single-effect heating and double-effect refrigeration includes a steam generator I13, a condenser I12, an evaporator I27, an absorber I28, a heat exchanger I31, and a solution pump I25 , refrigerant pump I26, steam generator II14, condenser II15, evaporator II22, absorber II21, heat exchanger II17, solution pump II24 and refrigerant pump II23;

The generator condenser housing of the unit also includes cavity I50 and cavity II51;

Both the condenser I12 and the steam generator I13 are arranged in the cavity I50;

Both the steam generator II14 and the condenser II15 are arranged in the cavity II51;

A low-pressure generator 36 is also added in the cavity II51, and the low-pressure generator 36 is arranged above the steam generator II14;

A refrigerant steam connecting pipe 35 is arranged between the gas phase region of the steam generator I13 and the tube side inlet of the low pressure generator 36;

A low-pressure generator refrigerant water pipe 37 is set between the outlet of the tube side of the low-pressure generator 36 and the inlet of the U-shaped pipe I29 of the condenser I12;

Set stop valve B34 on the hot water pipe going out of condenser II15 into condenser I12;

A cooling water outlet pipe is set on the hot water pipeline between the outlet condenser II15 and the shut-off valve B34, and a shut-off valve A33 is arranged on the cooling water outlet pipe.

The second steam inlet 48 of the cavity I50 is provided with a steam electric regulating valve A11;

The pipeline of the first steam inlet 38 of the cavity II51 is also provided with a steam electric regulating valve B16.

A U-shaped pipe II19 is also arranged between the condenser II15 and the evaporator II22.

During the heating operation of the heat pump in winter, the low-pressure generator 36 stops working, the stop valve A33 is closed, the stop valve B34 is opened, the concentrated solution valve A32 and the concentrated solution valve B18 can adjust the flow rate of the corresponding concentrated solution, the refrigerant water valve A30 and the refrigerant water Valve B20 can adjust the corresponding refrigerant water flow and maintain the pressure difference between the chambers. The unit operates according to the working principle of the two-stage lithium bromide absorption heat pump: steam generator I13, condenser I12, evaporator I27, absorber I28 and heat pump The exchanger I31 forms a low-temperature section heat pump cycle; the steam generator II14, condenser II15, evaporator II22, absorber II21 and heat exchanger II17 form a high-temperature section heat pump cycle. Because the refrigerant vapor temperature in the low-pressure generator 36 tubes is low, the solution is not concentrated, which is equivalent to stopping work. The steam from the external system is connected in parallel through the electric steam regulating valve A11 and the electric steam regulating valve B16 respectively to enter the steam generator I13 and the steam generator II14 tube side to condense the concentrated dilute solution into water and flow out of the unit; The cooling heat that enters the evaporator I27 tube side is utilized and then flows out of the unit; the hot water is connected in series to the absorber I28, absorber II21, condenser II15, and condenser I12 tubes to supply heat to the user after completing the entire heating process.

When operating in double-effect cooling mode in summer, the shut-off valve A33 is opened, the shut-off valve B34 is closed, the steam electric regulating valve B16 is closed, the condenser I12 and the steam generator II14 stop working, the concentrated solution valve A32 and the concentrated solution valve B18 can adjust the corresponding concentration Solution flow, refrigerant water valve A30 and refrigerant water valve B20 can adjust the corresponding refrigerant water flow and maintain the pressure difference between the chambers. The steam generator I13 becomes the high-pressure generator of the double-effect refrigeration unit. The high-pressure generator , low-pressure generator 36, condenser II15, evaporator I27, absorber I28, heat exchanger I31, evaporator II22, absorber II21, and heat exchanger II17 constitute a steam double-effect refrigeration unit in which the evaporator and absorber are divided into two sections , the unit operates according to the steam double-effect solution parallel refrigeration process. The steam from the external system enters the tube side of the steam generator I13 through the steam electric regulating valve A11 to condense the dilute solution into water and flows out of the unit; the cooling water enters the absorber I28 in series first, then enters the absorber II21, and then enters the condenser II15 tube side to take out the heat Unit; the cold water enters the evaporator II22 in series first, and then enters the evaporator I27 tube side to cool down and become the cold water supply for the cold user.

The above-mentioned evaporator absorber is divided into two stages, and the working principle of the steam double-effect solution parallel refrigeration process cycle is as follows: the solution pump I25 injects the dilute solution into the high-pressure generator and concentrates it into a concentrated solution, and the generated high-temperature refrigerant vapor passes through the refrigerant vapor The connecting pipe 35 enters the heat transfer tube of the low-pressure generator 36, and heats the dilute solution pumped into the low-pressure generator 36 by the solution pump II24 to make it into a concentrated solution. The refrigerant vapor in the heat transfer tube of the low-pressure generator 36 condenses into refrigerant water. The refrigerant water pipe 37 of the low-pressure generator enters the U-shaped pipe I29 and then enters the evaporator I27 for flashing; the refrigerant vapor generated by the concentrated dilute solution of the low-pressure generator 36 enters the condenser II15 for condensation, and the condensed refrigerant water enters the U-shaped pipe II19 then enters the evaporator II22 for flashing; the refrigerant water that is not flashed in the evaporator I27 is pumped into the evaporator I27 by the refrigerant pump I26 to absorb heat and evaporate on the surface of the heat transfer tube to produce cold water, and the evaporated refrigerant steam enters In the absorber I28, it is absorbed by the concentrated solution from the high-pressure generator and sprayed on the surface of the heat transfer tube of the absorber I28. The concentrated solution becomes a dilute solution and enters the bottom of the absorber I28; the refrigerant water that does not flash in the evaporator II22 The refrigerant pump II23 pumps into the surface of the heat transfer tube of the evaporator II22 to absorb heat and evaporate to produce cold water. The evaporated refrigerant vapor enters the absorber II21 and is sprayed on the surface of the heat transfer tube of the absorber II21 by the low-pressure generator 36. The concentrated solution is absorbed, and the concentrated solution becomes a dilute solution and enters the bottom of the absorber II21. The concentrated solution absorbs the heat released by the refrigerant vapor and is taken out of the unit by the cooling water. Such continuous circulation produces the required cold water for the user to use.

As shown in Figure 4, in another embodiment, the steam generator II14, condenser II15 and low-pressure generator 36 of a two-stage lithium bromide absorption unit of a single-effect heating and double-effect refrigeration according to the present invention In the same cavity, and the low-pressure generator is arranged below the steam generator II14.

In addition to the above-mentioned embodiments, the present invention also includes other implementations, and any technical solution formed by equivalent transformation or equivalent replacement shall fall within the protection scope of the claims of the present invention.

Claims (6)

1. A two-stage lithium bromide absorption heat pump unit for single-effect heating and double-effect refrigeration, said unit comprising a steam generator I (13), a condenser I (12), an evaporator I (27), and an absorber I (28), heat exchanger I (31), solution pump I (25), refrigerant pump I (26), steam generator II (14), condenser II (15), evaporator II (22), Absorber II (21), heat exchanger II (17), solution pump II (24) and refrigerant pump II (23); it is characterized in that: the generator condenser shell of the unit also includes cavity I ( 50) and cavity II (51); The condenser I (12) and the steam generator I (13) are both arranged in the cavity I (50); Both the steam generator II (14) and the condenser II (15) are arranged in the cavity II (51); A low pressure generator (36) is additionally installed in the cavity II (51); A refrigerant steam communication pipe (35) is provided between the gas phase area of the steam generator I (13) and the tube side inlet of the low pressure generator (36); A low-pressure generator refrigerant water pipe (37) is set between the outlet of the tube side of the low-pressure generator (36) and the inlet of the U-shaped tube I (29) of the condenser I (12); Set stop valve B (34) on the hot water pipeline from condenser II (15) to condenser I (12); Set a cooling water outlet pipe on the hot water pipeline between the outlet condenser II (15) and the shut-off valve B (34), and set the shut-off valve A (33) on the cooling water outlet pipe. 2. The single-effect heating and double-effect cooling two-stage lithium bromide absorption heat pump unit according to claim 1, characterized in that: the low-pressure generator (36) is set at the steam generator II (14) above or below. 3. A two-stage lithium bromide absorption heat pump unit with single-effect heating and double-effect refrigeration according to claim 1, characterized in that: the pipeline of the second steam inlet (48) of the cavity I (50) A steam electric regulating valve A (11) is provided; a steam electric regulating valve B (16) is also provided on the pipeline of the first steam inlet (38) of the cavity II (51). 4. A two-stage lithium bromide absorption heat pump unit with single-effect heating and double-effect refrigeration according to claim 1, characterized in that: there is a gap between the condenser II (15) and the evaporator II (22). A U-tube II (19) is provided. 5. A two-stage lithium bromide absorption heat pump unit with single-effect heating and double-effect refrigeration according to claim 1, characterized in that: when the heat pump is heating in winter, the low-pressure generator (36) stops working, and the cut-off Valve A (33) is closed, shut-off valve B (34) is opened, and the unit operates according to the working principle of the two-stage lithium bromide absorption heat pump. 6. A two-stage lithium bromide absorption heat pump unit with single-effect heating and double-effect cooling according to claim 3, characterized in that: when operating in double-effect cooling mode in summer, the cut-off valve A (33) is opened, and the cut-off valve A (33) is closed. Valve B (34) is closed, steam electric regulating valve B (16) is closed, condenser I (12) and steam generator II (14) stop working, and steam generator I (13) becomes the high-pressure generator of the double-effect refrigeration unit consists of high pressure generator, low pressure generator (36), condenser II (15), evaporator I (27), absorber I (28), heat exchanger I (31) and evaporator II (22), Absorber II (21) and heat exchanger II (17) constitute a steam double-effect refrigeration unit in which the evaporator absorber is divided into two sections, and the unit operates according to a steam double-effect solution parallel refrigeration process.