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

Abstract

The present invention relates to a two-stage lithium bromide absorption heat pump unit with single-effect heating and double-effect refrigeration, and belongs to the technical field of refrigeration equipment. The unit comprises a steam generator I, a condenser I, an evaporator I, an absorber I, a heat exchanger I, a solution pump I, a refrigerant pump I, a steam generator II, a low-pressure generator, a condenser II, an evaporator II, an absorber II, a heat exchanger II, a solution pump II, a refrigerant pump II, a stop valve A, and a stop valve B. The two-stage lithium bromide absorption heat pump unit with single-effect heating and double-effect refrigeration of the present invention is switched by valves. When the heating condition is operated in winter, the unit operates according to the two-stage heat pump principle; when the refrigeration condition is operated in summer, the unit operates according to the steam double-effect solution parallel refrigeration process. At the same time, the refrigeration performance coefficient of the double-effect refrigeration is greatly improved, steam consumption is saved, one machine has two uses, the initial investment of the equipment is reduced, and the floor space is saved.

Description

Technical Field

[0001] 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 Art

[0002] In areas where heat sources are needed in production processes and life, and where there is low-temperature waste heat, and where deep waste heat recovery is required, the waste water temperature drops greatly and the temperature is relatively low, while the produced hot water rises to a high temperature and the temperature difference is large. A multi-stage first-class lithium bromide absorption heat pump unit (such as Figure 1 It 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 comprehensive utilization of energy. In some occasions, not only heating in winter but also cooling in summer is required. In order to achieve dual-purpose use and save initial investment, steam type first-class lithium bromide absorption heat pump units with cooling function have appeared in the past two years (such as Figure 2 ), the unit's heating performance coefficient is about 1.7, and the cooling performance coefficient is about 0.75. In the case of deep waste heat recovery, the following is used Figure 2 The unit is not easy to realize, which will result in a small heat exchange temperature difference, a large heat exchange area, and a high material cost of the unit. 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 for both heating and cooling, reduce the material cost of the unit, and make the operation simple, safe and reliable, has become one of the important research topics at present. Summary of the invention

[0003] 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. The heat pump deeply recovers low-temperature waste heat for heating in winter and operates double-effect refrigeration in summer, thereby improving the refrigeration performance coefficient, saving energy, and reducing initial investment. It has a compact structure, is easy to operate, and is safe and reliable.

[0004] The object of the present invention is achieved in this way: a two-stage lithium bromide absorption unit with single-effect heating and double-effect refrigeration, comprising a steam generator I, a condenser I, an evaporator I, an absorber I, a heat exchanger I, a solution pump I, a refrigerant pump I, a steam generator II, a condenser II, an evaporator II, an absorber II, a heat exchanger II, a solution pump II and a refrigerant pump II.

[0005] The generator condenser housing of the unit also includes cavity I and cavity II;

[0006] The condenser 1 and the steam generator 1 are both arranged in the cavity 1;

[0007] The steam generator II and the condenser II are both arranged in the cavity II;

[0008] A low-pressure generator is also provided in the cavity II;

[0009] A refrigerant steam connecting pipe is provided between the gas phase region of the steam generator I and the inlet of the low-pressure generator tube side;

[0010] A low-pressure generator refrigerant water pipe is arranged between the low-pressure generator tube outlet and the U-shaped tube I inlet of the condenser I;

[0011] A stop valve B is installed on the hot water pipeline from condenser II to condenser I;

[0012] A cooling water outlet pipe is provided on the hot water pipeline between the outlet condenser II and the stop valve B, and a stop valve A is provided on the cooling water outlet pipe.

[0013] The low-pressure generator is arranged above or below the steam generator II.

[0014] A steam electric regulating valve A is provided on the second steam inlet pipeline of the cavity I;

[0015] The first steam inlet pipeline of the cavity II is also provided with a steam electric regulating valve B. A U-shaped tube II is also provided between the condenser II and the evaporator II. The refrigerant steam generated by the low-pressure generator concentrating the dilute solution enters the condenser II and the condensed refrigerant water enters the U-shaped tube II and then enters the evaporator II for flashing.

[0016] In winter, when the heat pump is heating, 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 corresponding concentrated solution flow, 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 cavities, and 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 exchanger I form a low-temperature heat pump cycle; steam generator II, condenser II, evaporator II, absorber II and heat exchanger II form a high-temperature heat pump cycle. Since the refrigerant steam temperature in the low-pressure generator tube is low, the solution is not concentrated, which is equivalent to stopping work. The steam from the external system is connected in parallel and enters the steam generator I and steam generator II pipes respectively through steam electric regulating valves A and B to concentrate the dilute solution and condense it into water to flow out of the unit; the waste hot water is connected in series and first enters the evaporator II for cooling and then enters the evaporator I pipe for cooling. The heat is used for cooling and then flows out of the unit; the hot water is connected in series in the absorber I, absorber II, condenser II, and condenser I pipes in sequence to complete the entire heating process and then provide heat to the user.

[0017] When operating in double-effect refrigeration mode in summer, stop valve A is opened, stop 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 concentrated solution flow, refrigerant water valve A and refrigerant water valve B can adjust the corresponding refrigerant water flow and maintain the pressure difference between each cavity, steam generator I becomes the high-pressure generator of the double-effect refrigeration unit, and the evaporator and absorber are divided into two sections, which are composed of high-pressure generator, low-pressure generator, condenser II, evaporator I, absorber I, heat exchanger I and evaporator II, absorber II, heat exchanger II. The unit operates according to the steam double-effect solution parallel refrigeration process. The steam from the external system enters the steam generator I tube pass through the steam electric regulating valve A to concentrate the dilute solution and condense it into water to flow out of the unit; the cooling water is connected in series and first enters the absorber I, then enters the absorber II, and then enters the condenser II tube pass to take the heat out of the unit; the cold water is connected in series and first enters the evaporator II, then enters the evaporator I tube pass to cool down and become the produced cold water to supply cold users.

[0018] The beneficial effects of the present invention are:

[0019] Through the above-mentioned new process and valve adjustment and switching, the heat pump heating condition and the completely different thermal field and flow field of the cooling condition can be safely and reliably operated on the same unit, achieving the purpose of deep recovery of waste heat for heating in winter and double-effect refrigeration in summer. The water system cools down or heats up in stages, increasing the concentration difference and heat exchange temperature difference of the unit solution, reducing the heat exchange area of ​​the unit, and reducing the material cost. Because it is double-effect refrigeration, the refrigeration performance coefficient is greatly improved, saving a lot of energy, one machine for two purposes, reducing the initial investment of the equipment, and saving the space occupied by the equipment. Therefore, the present invention can save energy and reduce emissions when providing heating in winter to achieve comprehensive utilization of energy, and can produce cold sources in summer to meet the use of air conditioning and production processes, thereby improving the annual operation utilization rate of the unit and having very good economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the working flow diagram of the previous two-stage steam type first-class lithium bromide absorption heat pump unit.

[0021] Figure 2 This is the working flow diagram of the previous steam-type first-class lithium bromide absorption heat pump unit with refrigeration function.

[0022] Figure 3 The present invention is a working flow chart of a two-stage lithium bromide absorption unit with single-effect heating and double-effect refrigeration.

[0023] Figure 4 This is a working flow chart of another embodiment of a two-stage lithium bromide absorption unit with single-effect heating and double-effect refrigeration of the present invention.

[0024] in:

[0025] 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 tube 10.

[0026] 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 tube 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 connecting pipe 35, low pressure generator 36, low pressure generator refrigerant water pipe 37, cavity I50, cavity II51;

[0027] First steam inlet 38, first condensate outlet 39, cold water outlet 40, waste hot water outlet 41, cold water inlet 42, waste 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 DESCRIPTION

[0028] The present invention is further described in detail below with reference to the accompanying drawings.

[0029] like Figure 3 As shown, 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, a solution pump I25, a refrigerant pump I26, a steam generator II14, a condenser II15, an evaporator II22, an absorber II21, a heat exchanger II17, a solution pump II24 and a refrigerant pump II23;

[0030] The generator condenser housing of the unit also includes a cavity I50 and a cavity II51;

[0031] The condenser I12 and the steam generator I13 are both arranged in the cavity I50;

[0032] The steam generator II14 and the condenser II15 are both arranged in the cavity II51;

[0033] A low-pressure generator 36 is further provided in the cavity II51, and the low-pressure generator 36 is arranged above the steam generator II14;

[0034] A refrigerant steam connecting pipe 35 is provided between the gas phase region of the steam generator I13 and the tube side inlet of the low pressure generator 36;

[0035] A low-pressure generator refrigerant water pipe 37 is provided between the low-pressure generator 36 tube outlet and the U-shaped tube 129 inlet of the condenser 112;

[0036] A stop valve B34 is provided on the hot water pipe from the outlet condenser II15 to the inlet condenser I12;

[0037] A cooling water outlet pipe is provided on the hot water pipeline between the outlet condenser II15 and the stop valve B34, and a stop valve A33 is provided on the cooling water outlet pipe.

[0038] A steam electric regulating valve A11 is provided on the second steam inlet 48 pipeline of the cavity I50;

[0039] A steam electric regulating valve B16 is also provided on the first steam inlet 38 pipeline of the cavity II51.

[0040] A U-shaped tube II19 is also provided between the condenser II15 and the evaporator II22.

[0041] In winter, when the heat pump is heating, 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 corresponding concentrated solution flow, 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 cavities, and the unit operates according to the working principle of the two-stage lithium bromide absorption heat pump: the steam generator I13, the condenser I12, the evaporator I27, the absorber I28 and the heat exchanger I31 form a low-temperature heat pump cycle; the steam generator II14, the condenser II15, the evaporator II22, the absorber II21 and the heat exchanger II17 form a high-temperature heat pump cycle. Since the refrigerant steam temperature in the low-pressure generator 36 pipe 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 steam electric regulating valve A11 and the steam electric regulating valve B16 to enter the steam generator I13 and steam generator II14 pipes respectively to concentrate the dilute solution and condense it into water to flow out of the unit; the waste hot water is connected in series to first enter the evaporator II22 for cooling and then enter the evaporator I27 pipe for cooling. The heat is used for cooling 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 pipes in sequence to complete the entire heating process and then provide heat to the users.

[0042] When operating in double-effect refrigeration mode in summer, stop valve A33 is opened, stop valve B34 is closed, steam electric regulating valve B16 is closed, condenser I12 and steam generator II14 stop working, concentrated solution valve A32 and concentrated solution valve B18 can adjust the corresponding concentrated solution flow, refrigerant water valve A30 and refrigerant water valve B20 can adjust the corresponding refrigerant water flow and maintain the pressure difference between each cavity, steam generator I13 becomes the high-pressure generator of the double-effect refrigeration unit, and the evaporator and absorber are divided into two sections of steam double-effect refrigeration unit composed of high-pressure generator, low-pressure generator 36, condenser II15, evaporator I27, absorber I28, heat exchanger I31 and evaporator II22, absorber II21, heat exchanger II17. The unit operates according to the steam double-effect solution parallel refrigeration process. The steam from the external system enters the steam generator I13 pipe line through the steam electric regulating valve A11 to concentrate the dilute solution and condense it into water to flow out of the unit; the cooling water is connected in series and first enters the absorber I28, then enters the absorber II21, and then enters the condenser II15 pipe line to take the heat out of the unit; the cold water is connected in series and first enters the evaporator II22, then enters the evaporator I27 pipe line to cool down and become the produced cold water to supply cold users.

[0043] The working principle of the steam double-effect solution parallel refrigeration process cycle in which the above-mentioned evaporator absorber is divided into two sections is as follows: the dilute solution is pumped into the high-pressure generator by the solution pump I25 to be concentrated into a concentrated solution, and the generated high-temperature refrigerant steam enters the heat transfer tube of the low-pressure generator 36 through the refrigerant steam connecting pipe 35, heats the dilute solution pumped into the low-pressure generator 36 by the solution pump II24 to make it a concentrated solution, and the refrigerant steam in the heat transfer tube of the low-pressure generator 36 condenses into refrigerant water, enters the U-shaped tube I29 through the refrigerant water pipe 37 of the low-pressure generator, and then enters the evaporator I27 to flash; the refrigerant steam generated by the low-pressure generator 36 concentrating the dilute solution enters the condenser II15 for condensation, and the condensed refrigerant water enters the U-shaped tube II19 and then enters the evaporator II22 to flash; in the evaporator The refrigerant water that has not flashed in the evaporator I27 is pumped into the surface of the heat transfer tube of the evaporator I27 by the refrigerant pump I26 to absorb heat and evaporate to produce cold water. The evaporated refrigerant vapor enters the absorber I28 and 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 has not flashed in the evaporator II22 is pumped into the surface of the heat transfer tube of the evaporator II22 by the refrigerant pump II23 to absorb heat and evaporate to produce cold water. The evaporated refrigerant vapor enters the absorber II21 and is absorbed by the concentrated solution from the low-pressure generator 36 and sprayed on the surface of the heat transfer tube of the absorber II21. 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 carried out of the unit by the cooling water. In this way, the required cold water is produced in a continuous cycle for users to use.

[0044] like Figure 4As shown, in another embodiment, the steam generator II14, condenser II15 and low-pressure generator 36 of the two-stage lithium bromide absorption unit with single-effect heating and double-effect refrigeration described in the present invention are in the same cavity, and the low-pressure generator is arranged below the steam generator II14.

[0045] In addition to the above embodiments, the present invention also includes other implementation modes. Any technical solutions formed by equivalent transformation or equivalent replacement should fall within the protection scope of the claims of the present invention.

Claims

1. A two-stage lithium bromide absorption heat pump unit with single-effect heating and double-effect cooling, the unit comprising a steam generator I (13), a condenser I (12), an evaporator I (27), an absorber I (28), a heat exchanger I (31), a solution pump I (25), a refrigerant pump I (26), a steam generator II (14), a condenser II (15), an evaporator II (22), an absorber II (21), a heat exchanger II (17), a solution pump II (24) and a refrigerant pump II (23); characterized in that: The generator condenser housing of the unit further includes a cavity I (50) and a cavity II (51); The condenser I (12) and the steam generator I (13) are both arranged in the cavity I (50); The steam generator II (14) and the condenser II (15) are both arranged in the cavity II (51); A low-pressure generator (36) is also provided in the cavity II (51); A refrigerant steam connecting pipe (35) is provided between the gas phase region 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 provided between the tube outlet of the low-pressure generator (36) and the inlet of the U-shaped tube I (29) of the condenser I (12); A stop valve B (34) is provided on the hot water pipeline from the outlet of condenser II (15) to the inlet of condenser I (12); A cooling water outlet pipe is provided on the hot water pipeline between the outlet condenser II (15) and the stop valve B (34), and a stop valve A (33) is provided on the cooling water outlet pipe; A steam electric regulating valve A (11) is provided on the second steam inlet (48) pipeline of the cavity I (50); a steam electric regulating valve B (16) is also provided on the first steam inlet (38) pipeline of the cavity II (51); In winter, when the heat pump is in heating operation, the low-pressure generator (36) stops working, the stop valve A (33) is closed, the stop valve B (34) is opened, and the unit operates according to the working principle of a two-stage lithium bromide absorption heat pump: the steam generator I (13), the condenser I (12), the evaporator I (27), the absorber I (28) and the heat exchanger I (31) form a low-temperature heat pump cycle; Steam generator II (14), condenser II (15), evaporator II (22), absorber II (21) and heat exchanger II (17) form a high-temperature heat pump cycle. Since the refrigerant steam temperature in the low-pressure generator (36) tube is low and the solution is not concentrated, the steam from the external system is connected in parallel through the steam electric regulating valve A (11) and the steam electric regulating valve B (16) to enter the steam generator I (13) and steam generator II (14) tubes respectively to concentrate the dilute solution and condense it into water to flow out of the unit; the waste hot water is connected in series to first enter the evaporator II (22) for cooling and then enter the evaporator I (27) tube for cooling. The heat is used for cooling and then flows out of the unit; the hot water is connected in series to the absorber I (28), absorber II (21), condenser II (15) and condenser I (12) tubes in sequence to complete the entire heating process and then provide heat to the user; In the summer, when the double-effect refrigeration unit is in operation, the stop valve A (33) is opened, the stop valve B (34) is closed, the steam electric regulating valve B (16) is closed, the condenser I (12) and the steam generator II (14) stop working, and the steam generator I (13) becomes the high-pressure generator of the double-effect refrigeration unit, which is composed of the high-pressure generator, the low-pressure generator (36), the condenser II (15), the evaporator I (27), the absorber I (28), the heat exchanger I (31) and the evaporator II (22), the absorber II (21), the heat exchanger II (17). The steam double-effect refrigeration unit is divided into two sections, the evaporator and the absorber. The unit operates according to the steam double-effect liquid parallel refrigeration process. The steam from the external system enters the steam generator I (13) pipe line through the steam electric regulating valve A (11) to concentrate the dilute solution and condense it into water to flow out of the unit; the cooling water is connected in series to first enter the absorber I (28), then enter the absorber II (21), and then enter the condenser II (15) pipe line to take the heat out of the unit; the cold water is connected in series to first enter the evaporator II (22), then enter the evaporator I (27) pipe line to cool down and become the produced cold water to supply cold users.

2. A two-stage lithium bromide absorption heat pump unit with single-effect heating and double-effect cooling according to claim 1, characterized in that: The low-pressure generator (36) is arranged above or below the steam generator II (14).

3. A two-stage lithium bromide absorption heat pump unit with single-effect heating and double-effect cooling according to claim 1, characterized in that: A U-shaped tube II (19) is also provided between the condenser II (15) and the evaporator II (22).

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